BACKGROUND OF THE INVENTION
[0001] This invention relates generally to systems and methods for determining effluent
concentration profiles.
[0002] Determination of the service life of filter cartridges or filter beds in the filter
cartridges of air purifying respirators is a regulatory requirement in the United
States. Moreover, many users of air purifying respirators desire to have change out
data and/or an estimated service life calculation. Change out data may include, for
example, a schedule for when the cartridges in air purifying respirators should be
changed out, or replaced, with new cartridges. The estimated service life calculation
may include a determination of how long the cartridges in an air purifying respirator
should last. Both the change out data and the estimated service life calculation may
be based in whole or part on the input of the conditions in which the cartridges and
respirators are used.
[0003] Known methods and systems used to determine change out data and service life calculations
for air purifying respirator cartridges have several shortcomings. For example, known
systems and methods do not provide a graphical output of an effluent concentration
profile, a breakthrough time or a service life of a filter cartridge. Also, these
systems and methods do not provide for dynamic calculation of an effluent concentration
profile, a breakthrough time or a service life based on dynamically changing inputs
from a user. Moreover, to the extent these systems and methods do determine a breakthrough
time or service life, the mathematical models upon which the breakthrough time or
service life is based do not accurately determine the breakthrough time or service
life for many contaminants, including many contaminants having relatively low molecular
weights and/or low boiling points.
[0004] WO2009/029326, which is considered to represent the closest prior art, discloses a method and associated
system for determining a condition of a component coupled to an article of personal
protection equipment, the method comprising providing at least one component removably
coupled to an article of personal protection equipment; providing a smart tag coupled
with the component or the article; tracking usage of the component, said tracking
comprising retrieving data from the smart tag; and, determining a condition of the
component based on comparing tracked data of the component against at least one predetermined
criterion.
[0005] Thus, a need exists for a system and method for determining change out data and service
life calculations for air purifying respirator cartridges that provide a graphical
output of effluent concentration profiles, allow for dynamic calculations of service
life calculations and are based on more accurate models.
BRIEF DESCRIPTION OF THE INVENTION
[0006] According to a first aspect of the present invention there is provided a method for
determining an effluent concentration profile according to claim 1.
[0007] The present invention further provides a system for determining an effluent concentration
profile according to claim 4.
[0008] In order that the invention may be well understood, there will now be described an
embodiment thereof, given by way of example, reference being made to the accompanying
drawings, in which:
Figure 1 is a block diagram of an effluent concentration calculation system according
to the invention;
Figure 2 is an illustration of a graphical user interface used to enter one or more
parameters into the system shown in Figure 1 and to display output shown in Figure
1 to a user according to one embodiment;
Figure 3 is an illustration of a graphical user interface used to enter one or more
parameters into the system shown in Figure 1 according to one embodiment;
Figure 4 is a flowchart for a method of determining at an effluent concentration profile
according to the invention;
Figure 5 illustrates a block diagram of exemplary manners in which one or more embodiments
described herein may be stored, distributed and installed on computer-readable medium;
and
Figure 6 is an exploded view of a filter cartridge according to example embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The foregoing summary, as well as the following detailed description of certain embodiments
of the present invention, will be better understood when read in conjunction with
the appended drawings. To the extent that the figures illustrate diagrams of the functional
blocks of various embodiments, the functional blocks are not necessarily indicative
of the division between hardware circuitry. Thus, for example, one or more of the
functional blocks (for example, processors or memories) may be implemented in a single
piece of hardware (for example, a general purpose signal processor or random access
memory, hard disk, or the like). Similarly, the programs may be stand alone programs,
may be incorporated as subroutines in an operating system, may be functions in an
installed software package, and the like. It should be understood that the various
embodiments are not limited to the arrangements and instrumentality shown in the drawings.
[0010] As used herein, an element or step recited in the singular and proceeded with the
word "a" or "an" should be understood as not excluding plural of said elements or
steps, unless such exclusion is explicitly stated. Furthermore, references to "one
embodiment" of the present invention are not intended to be interpreted as excluding
the existence of additional embodiments that also incorporate the recited features.
Moreover, unless explicitly stated to the contrary, embodiments "comprising" or "having"
an element or a plurality of elements having a particular property may include additional
such elements not having that property.
[0011] It should be noted that although one or more embodiments may be described in connection
with a filter cartridge for an air purifying respirator, the embodiments described
herein are not limited to air purifying respirators. In particular, one or more embodiments
may be implemented in connection with different types of filtration systems, including,
for example, air filtration systems for buildings. Moreover, while one or more embodiments
may be described as being implemented using one or more computer devices or systems,
the embodiments described herein are not limited to computer-based systems and methods.
In particular, one or more embodiments may be implemented in connection with non-computer
based devices and methods. For example, while one embodiment includes calculating
a breakthrough time or a service life of a filter cartridge based on one or more parameters
input by a user into a computer-based system, the breakthrough time or service life
may be calculated using a slide rule or a wheel calculator. The slide rule or wheel
calculator can provide a breakthrough time or service life based on various known
inputs.
[0012] Example embodiments of systems and methods for calculating and displaying information
are described in detail below. In particular, a detailed description of example systems
and methods for dynamically determining and displaying effluent concentration profiles,
breakthrough times and filter cartridge recommendations is provided. A technical effect
of one or more of the embodiments described herein includes at least one of graphically
displaying a breakthrough time and/or effluent concentration profile based on one
or more parameters input by a user, dynamically adjusting the breakthrough time and/or
effluent concentration profile based on changed inputs from a user, recommending a
filter cartridge to a user based on input from a user, and dynamically altering a
recommended filter cartridge based on changed inputs from a user.
[0013] Figure 6 is an exploded view of a filter cartridge 600 according to example embodiment.
The filter cartridge 600 includes top and bottom bodies 602, 604 that house a filter
bed 606. The filter bed 606 may include, for example, activated carbon impregnated
with one or more chemicals. A plurality of additional filter layers 608, 610 may each
include additional layers of activated carbon. Retention elements 612, 614 may hold
the filter layers 608, 610 within the filter cartridge 600. A screen 616 mechanically
filters aerosol particles passing through the filter cartridge 600. A sealing element
618 and an adhesive 620 are provided to seal the filter cartridge 600 in an assembled
state. In operation, air passes through an intake port 622 in the bottom body 604
and passes through the filter layers 608, 610 and the filter bed 606. As the air passes
through the filter layers 608, 610 and the filter bed 606, one or more chemical contaminants
in the air may be filtered out or adsorbed to the material in the filter layers 608,
610 and/or the filter bed 606. The filtered air continues through the filter cartridge
600 and out of the filter cartridge 600 through a port 624 in the top body 602. The
filtered air may then be communicated to a user through one or more tubes or pipes,
for example. The effectiveness of the filter bed 606 may decrease with continued use.
For example, as more and more contaminated air passes through the filter bed 606 and/or
as higher concentrations of chemical contaminants pass through the filter bed 606,
the filter bed 606 becomes less effective in filtering out the chemical contaminants.
Eventually, the concentration of the chemical contaminants passing through the filter
bed 606 may exceed a maximum allowable concentration. The time at which this occurs
may be referred to as the breakthrough time or service life of the filter cartridge
600. Once the breakthrough time or service life of the filter cartridge 600 has passed,
the filter cartridge 600 may no longer be usable to protect the user from the chemical
contaminants.
[0014] Figure 1 is a block diagram of an effluent concentration calculation system 100 according
to one embodiment. The system 100 includes a processor module 102 that receives, among
other things, input 104 from a user at a user interface 106 and determines at least
one of an effluent concentration profile 204 (shown in Figure 2 and embodying the
invention), a breakthrough time 206 (shown in Figure 2 and outside the scope of the
invention), and a filter cartridge recommendation 240 (shown in Figure 2 and outside
the scope of the invention). The effluent concentration profile 204 includes a graphical
representation of the concentration of one or more chemical species that pass through
a filter bed of a filter cartridge over time. In one embodiment, the effluent concentration
profile 204 represents the concentration of one or more chemical species at one end
of the filter bed 606 (shown in Figure 6) with respect to time. For example, the effluent
concentration profile 204 represents the concentration of a chemical species at the
end of the filter bed 606 that is closest to the port 624 (shown in Figure 6) in the
top body 602 (shown in Figure 6) of the filter cartridge 600 (shown in Figure 6).
In such an example, the effluent concentration profile 204 represents the approximate
concentration of the chemical species that passes through the filter cartridge 600
to the user of the filter cartridge 600. The breakthrough time 206 includes a time
at which a given concentration of one or more chemical species breaks through the
filter cartridge from the surrounding environment and reaches a user of the filter
cartridge. The filter cartridge recommendation 240 includes one or more filter cartridges
recommended to the user based on criterion set forth by the user.
[0015] In another embodiment, the processor module 102 receives input 104 from the user
at the user interface 106 and determines a bed profile. The bed profile is a graphical
representation of the concentration of one or more chemical species in the filter
bed 606 (shown in Figure 6) with respect to the position in the filter bed 606. For
example, the bed profile may graphically illustrate the concentration of a chemical
species in the filter bed 606 with respect to various positions in the thickness of
the filter bed 606 at a given time. The processor module 102 determines the bed profile
for a variety of times in one embodiment. The movement of the chemical species through
the filter bed 606 may then be visualized by comparing a plurality of bed profiles
generated by the processor module 102 at increasing time periods.
[0016] The processor module 102 and the user interface 106 are directly or indirectly communicatively
coupled with one another through one or more wired, wireless, or network (such as
a LAN, WAN, Internet or intranet) connections. The user interface 106 includes a device,
system or apparatus capable of communicating one or more input parameters and communicating
the input parameters as the input 104 to the processor module 102. For example, the
user interface 106 can include one or more of a keyboard, mouse, stylus, touch-sensitive
screen, microphone, and the like. In another example, the user interface 106 includes
a stand-alone computing device such as a PC, a laptop computer, a smart phone, and
the like. In one embodiment, the processor module 102 and the user interface 106 communicate
with one another through one or more network connections (including the Internet).
For example, the system 100 may be an Internet-based system that employs a web browser
as the user interface 106.
[0017] In the illustrated embodiment, the processor module 102 is communicatively coupled
to a computer-readable storage medium 110. The computer-readable storage medium 110
may include one or more computer-readable memories capable of storing data, such as
a hard drive, RAM, ROM, flash memory, CD drive, DVD drive, and the like. The computer-readable
storage medium 110 may directly or indirectly communicate with the processor module
102 through one or more wired, wireless, or network (such as a LAN, WAN, Internet,
or intranet) connections. In another embodiment, a plurality of computer-readable
storage mediums is communicatively coupled to the processor module 102. For example,
an additional computer-readable storage medium 112 may be communicatively coupled
to the processor module 102. The computer-readable storage medium 112 may include
a database 114 that stores one or more parameters usable by the processor module 102
to determine at least one of the effluent concentration profile 204 (shown in Figure
2), the breakthrough time 206 (shown in Figure 2), and the filter cartridge recommendation
240 (shown in Figure 2).
[0018] The processor module 102 is communicatively coupled to an output device 108. The
output device 108 includes a device, system or apparatus capable of receiving the
effluent concentration profile 204, the breakthrough time 206, the filter cartridge
recommendation 240, a bed profile and/or data representative of the effluent concentration
profile 204, the breakthrough time 206, the filter cartridge recommendation 240 and/or
the bed profile and presenting the same to the user. For example, the output device
108 can include a CRT display, a printer, a mobile display unit such as a Palm Pilot,
mobile phone, Blackberry, and the like, a computer memory, an LCD screen, and the
like. In one embodiment, the processor module 102 and the output device 108 communicate
with one another through one or more network connections (including the Internet).
For example, the system 100 may be an Internet-based system that employs a web browser
as the output device 108. The processor module 102 communicates the effluent concentration
profile 204, the breakthrough time 206, the filter cartridge recommendation 240 and/or
data representative of the same as output 120 to the output device 108. A plurality
of the processor module 102, user interface 106 and output device 108 are physically
separate components of the system 100 in one embodiment. Alternatively, a plurality
of the processor module 102, user interface 106 and output device 108 are combined
into a single component. For example, the processor module 102 and the output device
108 may be provided as one or more microprocessors and an LCD screen housed within
an air respirator.
[0019] In one embodiment, the processor module 102 is communicatively coupled to an active
sensor 116. The active sensor 116 includes a powered device configured to sense or
measure data relevant to one or more parameters. The data or parameters are usable
by the processor module 102 to determine at least one of the effluent concentration
profile 204, the breakthrough time 206, and the filter cartridge recommendation 240.
The processor module 102 and active sensor 116 may be directly or indirectly connected
through one or more wired, wireless, or network (such as a LAN, WAN, Internet, or
intranet) connections. The active sensor 116 may proactively report measured or sensed
data to the processor module 102 as input 122. For example, the active sensor 116
may be a powered sensor capable of communicating parameters to the processor module
102 as input 122.
[0020] In one embodiment, the processor module 102 is communicatively coupled to a passive
sensor 118. The passive sensor 118 includes a non-powered device configured to sense
data relevant to one or more parameters. The data or parameters are usable by the
processor module 102 to determine at least one of the effluent concentration profile
204, the breakthrough time 206, and the filter cartridge recommendation 240. The processor
module 102 and passive sensor 118 may be directly or indirectly connected through
one or more wired, wireless, or network (such as a LAN, WAN, Internet, or intranet)
connections. The processor module 102 may measure the data or parameters from the
passive sensor 118 as input 124.
[0021] The processor module 102 includes a plurality of sub-modules, including a recommended
filter cartridge sub-module 126, an effluent concentration profile sub-module 128,
a breakthrough time sub-module 130, and an output sub-module 132. The processor module
102 is illustrated conceptually as a collection of sub-modules 126 through 132, but
may be implemented utilizing any combination of dedicated hardware boards, DSPs, processors,
etc. Alternatively, the processor module 102 and/or the sub-modules 126 through 132
may be implemented utilizing an off-the-shelf PC with a single processor or multiple
processors, with the functional operations distributed between the processors. As
a further option, the sub-modules 126 through 132 may be implemented utilizing a hybrid
configuration in which certain modular functions are performed utilizing dedicated
hardware, while the remaining modular functions are performed utilizing an off-the-shelf
PC and the like. The sub-modules 126 through 132 also may be implemented as software
modules within a processing unit.
[0022] The operations of the sub-modules 126 through 132 may be controlled by the processor
module 102. The sub-modules 126 through 132 may perform mid-processor operations,
for example. The recommended filter cartridge sub-module 126 receives one or more
input parameters (described below), accesses any of a list, table, database, and the
like, of available filter cartridges, and recommends one or more filter cartridges
in the list based on the input parameters. For example, the user may input several
criteria for a filter cartridge as one or more input parameters described below. The
recommended filter cartridge sub-module 126 receives these criteria and narrows down
the list of all potential filter cartridges. Based on these criteria and the remaining
filter cartridges, the recommended filter cartridge sub-module 126 selects one or
more filter cartridges to recommend to the user. The initial list of possible filter
cartridges to recommend may be stored in one or more of the computer-readable storage
media 110, 112.
[0023] The effluent concentration profile ("ECP") sub-module 128 receives one or more input
parameters (described below) and calculates the effluent concentration profile or
curve 204 (shown in Figure 2) and/or a bed profile. For example, the user may input
several parameters for calculating the effluent concentration profile for a filter
cartridge in an environment with one or more chemical contaminants at one or more
concentrations. The ECP sub-module 128 receives these parameters and calculates an
effluent concentration profile 204 based on the parameters and one or more mathematical
models for calculating the effluent concentration profile 204 based on the parameters.
In one embodiment, the ECP sub-module 128 obtains one or more default values for any
parameters or variables required by the mathematical model used to calculate the effluent
concentration profile 204 but that is not input by the user. For example, the ECP
sub-module 128 may obtain the default values for any variables not input by the user
from one or more of the computer-readable storage media 110, 112.
[0024] The breakthrough time sub-module 130 receives one or more input parameters (described
below) and calculates a breakthrough time 206 (shown in Figure 2). For example, the
user may input several parameters for calculating the service life of a filter cartridge
in an environment with one or more chemical contaminants at one or more concentrations.
The breakthrough time sub-module 130 receives these parameters and calculates a breakthrough
time 206 based on the parameters and one or more mathematical models for calculating
the breakthrough time 206 based on the parameters. In one embodiment, the breakthrough
time sub-module 130 obtains one or more default values for any parameters or variables
required by the mathematical model used to calculate the breakthrough time 206 but
that is not input by the user. For example, the breakthrough time sub-module 130 may
obtain the default values for any variables not input by the user from one or more
of the computer-readable storage media 110, 112.
[0025] The output sub-module 132 communicates the output of one or more of the sub-modules
126 through 130 (described above) to the output device 108 as the output 120. The
output sub-module 132 may cause the output 120 to graphically display the output 120,
to print the output 120, or to otherwise communicate the output 120 to the user of
the system 100.
[0026] In operation, the processor module 102 receives one or more parameters and uses the
parameters to generate the effluent concentration profile 204, the breakthrough time
206, a bed profile at one or more times, and/or the filter cartridge recommendation
240. In a first operational mode referred to as a service life calculation mode, the
processor module 102 obtains or receives one or more parameters to determine one or
more of the effluent concentration profile 204 and the breakthrough time 206. In a
second operational mode referred to as a cartridge selection mode, the processor module
102 obtains or receives one or more parameters to determine a recommended filter cartridge.
The processor module 102 may perform both the service life calculation mode and the
cartridge selection mode concurrently or separately.
[0027] In the service life calculation mode, the effluent concentration profile 204 or the
breakthrough time 206 can be used to represent the service life of a filter cartridge
based on the parameters. For example, based on the input parameters, the processor
module 102 can determine how long a filter cartridge can be used before one or more
chemical contaminants breakthrough the filter at an unsafe level and reach the user.
The input parameters used by the processor module 102 in the service life calculation
mode include, but are not limited to, one or more use condition parameters. The use
condition parameters include data or information relevant to the manner in which a
filter cartridge is or will be used. For example, the use condition parameters may
include, but are not limited to, one or more of a cartridge type, a chemical contaminant,
a chemical concentration, an occupational exposure limit, and a site condition.
[0028] The cartridge type is the type of filter cartridge that is being used or that is
desired to be used. For example, a cartridge type that is desired by a user to be
included in an air respirator can be input by a user at the user interface 106 and
communicated to the processor module 102 as the input 104. In another example, the
active sensor 116 can determine what filter cartridge is being used by a user and
communicate the cartridge type to the processor module 102 as the input 122. In another
example, the cartridge type can be determined by the processor module 102 based on
a user's preference for a particular type of respirator and/or a particular particulate
protection level. The type of respirator can include the make and/or model of the
air respirator in which the filter cartridge is used or will be used. The particulate
protection level can include the amount of chemical particulates that the user deems
can be allowed to pass through the filter cartridge to the user. The type of respirator
and/or particulate protection level can be input by a user with the user interface
106 and communicated as the input 104. Alternatively, the type of respirator can be
determined by one or more of the active and passive sensors 116, 118 and communicated
to the processor module 102 as the input 122, 124. Based on the type of respirator
and/or particulate protection level, the processor module 102 can narrow down a list
of all potential filter cartridges available to a user. A list of available filter
cartridges can be stored at one or more of the computer-readable storage media 110,
112. The processor module 102 can access the list and eliminate those filter cartridges
that do not meet the criteria defined by the type of respirator and/or particulate
protection level. For example, some filter cartridges in the list may not work in
the type of respirator input to the processor module 102. Based on the narrowed list
of potential filter cartridges, the processor module 102 can determine the effluent
concentration profile 204 and/or the breakthrough time 206 for one or more filter
cartridges in the narrowed list. Alternatively, the processor module 102 can present
the narrowed list of filter cartridges to the user at the output device 108. The user
can then select one or more filter cartridges from the list using the user interface
106.
[0029] The chemical contaminant is one or more chemical species that are to be filtered
by the filter cartridge. The chemical contaminants can include those chemical species
that are detected by the passive and/or active sensors 118, 116 and communicated to
the processor module 102 as the input 124, 122. Alternatively, the chemical contaminants
can include those chemical species input by a user with user interface 106 and communicated
as the input 104.
[0030] The chemical concentration is the concentration of one or more of the chemical contaminants
in an environment where the filter cartridge is used or will be used. For example,
the chemical concentration may be a vapor, liquid and/or aerosol concentration. The
chemical concentration can include the concentrations that are detected by the passive
and/or active sensors 118, 116 and communicated to the processor module 102 as the
input 124, 122. Alternatively, the chemical concentration can include the concentrations
of those chemical species input by a user with user interface 106 and communicated
as the input 104. In another embodiment, the chemical concentration is the maximum
concentration of one or more of the chemical contaminants that passes, or breaks through,
a filter cartridge. This maximum concentration may be referred to as a breakthrough
concentration. The processor module 102 may obtain a default value for the chemical
concentration parameter. For example, the processor module 102 may obtain a default
value for the chemical concentration of a chemical contaminant input by the user from
one or more of the computer-readable storage media 110, 112. The default value for
the chemical concentration parameter may be associated with one or more of the other
parameters input by the user. For example, the default value used for the chemical
concentration may be different for different chemical contaminants and/or cartridge
types that are input by the user. The association between various default values for
one or more of the chemical concentration parameters and the input parameters from
the user may be stored in a table, database, or other memory structure in at least
one of the computer-readable storage media 110, 112.
[0031] The occupational exposure limit includes one or more limits on the amount or concentration
of one or more chemical contaminants in an environment that a filter cartridge is
to be used. For example, the occupational exposure limit may be a legally mandated
limit on the amount or concentration of a chemical contaminant that a human being
may be exposed to during a particular time period. The occupational exposure limit
may be input by a user at the user interface 106 and communicated as the input 104.
Alternatively, the occupational exposure limit may be stored at the computer-readable
storage medium 110 and/or 112 and obtained by the processor module 102 from the same.
The processor module 102 may obtain a default value for the occupational exposure
limit parameter. For example, the processor module 102 may obtain a default value
for the occupational exposure limit from one or more of the computer-readable storage
media 110, 112. The default value for the occupational exposure limit parameter may
be associated with one or more of the other parameters input by the user. For example,
the default value used for the occupational exposure limit may be different for different
chemical contaminants and/or cartridge types that are input by the user. The association
between various default values for the occupational exposure limit parameter and one
or more other input parameters from the user may be stored in a table, database, or
other memory structure in at least one of the computer-readable storage media 110,
112.
[0032] The site condition parameter includes one or more parameters relevant to the environment
in which a filter cartridge is being used or will be used. For example, an ambient
pressure, temperature, and/or relative humidity may be communicated to the processor
module 102 as a site condition parameter. In one embodiment, a breathing rate is communicated
to the processor module 102 as a site condition parameter. The breathing rate is the
breathing rate desired by a user or is a measured breathing rate of a user currently
using a particular filter cartridge. One or more of the site conditions may be input
by a user at the user interface 106 and communicated to the processor module 102 as
the input 104. In one embodiment, the active and/or passive sensors 116, 118 measure
or sense one or more site conditions and the site conditions are received by the processor
module 102 as the input 122 and/or 124. The processor module 102 may obtain default
values for one or more site condition parameters. For example, the processor module
102 may obtain a default value for the ambient pressure, temperature, relative humidity,
and/or breathing rate from one or more of the computer-readable storage media 110,
112. The default value for the site condition parameter may be associated with one
or more of the parameters input by the user. Different default values for one or more
of the site condition parameters may be associated with different chemical contaminants
and/or cartridge types input by the user. For example, the default value used for
the breathing rate may be different for different chemical contaminants and/or cartridge
types that are input by the user. The association between various default values for
one or more of the site condition parameters and the input parameters from the user
may be stored in a table, database, or other memory structure in at least one of the
computer-readable storage media 110, 112.
[0033] In one embodiment, the user inputs a confidence level that is associated with one
or more of the parameters. For example, the user may input a confidence level of 5%
for one or more of the ambient pressure, the breathing rate, the temperature, the
relative humidity, the chemical concentration, and the like. Other confidence levels
may be input by the user. In general, a larger confidence level indicates that the
user has less confidence in the numeric value of the input parameter. For example,
a confidence level of 5% for an input temperature parameter of 27 degrees celsius
(80 degrees Fahrenheit) indicates that the user believes that the temperature parameter
is between 24 and 29 degrees celsius (76 and 84 degrees Fahrenheit). In comparison,
a confidence level of 10% for the temperature parameter of 27 degrees celsius (80
degrees Fahrenheit) indicates that the user believes that the temperature parameter
is between 22 and 31 degrees celsius (72 and 88 degrees Fahrenheit).
[0034] In the service life calculation mode, the processor module 102 receives one or more
of the use condition parameters and, based on the parameters and one or more mathematical
models applied to the parameters, generates the effluent concentration profile 204
and/or the breakthrough time 206. Either or both of the effluent concentration profile
204 and the breakthrough time 206 can be used to determine how long a particular cartridge
can be used by the user in an environment and manner of use described by the use condition
parameters. For example, with a given type of filter cartridge to be used in an environment
with particular chemical contaminants at given concentrations, the effluent concentration
profile 204 and/or the breakthrough time 206 can be used to determine how long the
cartridge can be used in the environment before one or more chemical contaminants
breakthrough the filter cartridge and reach the user.
[0035] In one embodiment, the processor module 102 does not determine the effluent concentration
profile 204 and/or the breakthrough time 206 until a minimum number or amount of the
use condition parameters are received by the processor module 102. For example, the
processor module 102 may not determine the effluent concentration profile 204 and/or
the breakthrough time 206 until the cartridge type, the chemical contaminant(s) and
the chemical concentration(s) are received by the processor module 102. In one embodiment,
the processor module 102 obtains default values for any other parameters or variables
that are required to generate the effluent concentration profile 204 and/or the breakthrough
time 206. These default values may be obtained from one or more of the computer-readable
storage media 110, 112.
[0036] The processor module 102 communicates the bed profile, the effluent concentration
profile 204 and/or the breakthrough time 206 (or data representative of either) to
the output device 108 as the output 120. The output device 108 provides the effluent
concentration profile 204 and/or the breakthrough time 206 to the user. For example,
the output device 108 may display the effluent concentration profile 204 and/or the
breakthrough time 206 plotted on a graph. Alternatively, the output device 108 may
display the effluent concentration profile 204 and/or the breakthrough time 206 as
a tabular report provided to the user. In one embodiment, the processor module 102
determines the effluent concentration profile 204 and/or the breakthrough time 206
and the output device 108 presents the same to a user. The user may then alter, change
or add to the parameters input to the processor module 102. The processor module 102
then determines an updated version of the effluent concentration profile 204 and/or
the breakthrough time 206 and the output device 108 presents the same to the user.
For example, the user may change the parameters input to the processor module 102
and the processor module 102 dynamically changes or updates the effluent concentration
profile 204 and/or the breakthrough time 206 in response thereto. By updating the
effluent concentration profile 204 and/or the breakthrough time 206, the user may
then visually see the impact of varying one or more parameters on the effluent concentration
profile 204 and/or the breakthrough time 206.
[0037] In one embodiment, the processor module 102 determines at least one of a bed profile,
the effluent concentration profile 204 and/or the breakthrough time 206 (or data representative
of any of the bed profiles, effluent concentration profiles 204 and/or breakthrough
times 206) for each of a plurality of chemical species or contaminants and communicates
the same to the output device 108 as the output 120. The output device 108 displays
the plurality of bed profiles, effluent concentration profiles 204, and/or breakthrough
times 206. For example, a plurality of effluent concentration profiles 204 may be
displayed on a single graph, with each effluent concentration profile 204 representing
the concentration of a different chemical species or contaminant. Alternatively, the
processor module 102 determines, and the output device 108 displays, at least one
bed profile, effluent concentration profile 204 and/or breakthrough time 206 for each
of a plurality of different parameter scenarios. A parameter scenario includes a set
of parameters input by the user. Different parameter scenarios may include different
permutations of the potential input parameters that are input by the user. For example,
different parameter scenarios may include one or more different chemical contaminants,
different sets of chemical contaminants, different filter cartridges, and the like.
The user may then easily visually compare the bed profiles, effluent concentration
profiles 204, and/or breakthrough times 206 for different chemical contaminants and/or
parameter scenarios at the same time.
[0038] A plurality of the parameter scenarios are saved and stored in one or more computer-readable
storage media and are accessible by the processor module 102 in one embodiment. For
example, several parameter scenarios may be stored in the computer-readable storage
medium 110. The user may select one or more parameter scenarios to be communicated
to the processor module 102. The parameters of the parameter scenario may be communicated
to the output device 108 and presented to the user. The processor module 102 may then
employ one or more of the parameters in the parameter scenario selected by the user
to determine a bed profile, the effluent concentration profile 204 and/or the breakthrough
time 206. In one embodiment, the user selects a parameter scenario previously input
and saved by another user and then modifies one or more parameters in the parameter
scenario, inputs additional parameters to the parameter scenario and/or removes one
or more parameters from the parameter scenario. The processor module 102 may then
determine the effluent concentration profile 204, for example, based on this modified
parameter scenario.
[0039] In one embodiment, the processor module 102 determines at least one of a bed profile,
the effluent concentration profile 204 and/or the breakthrough time 206 (or data representative
of any of the bed profiles, effluent concentration profiles 204 and/or breakthrough
times 206) for one or more values of an input parameter, with the values being within
the range of values that fall within the confidence level for that input parameter.
For example, if the user inputs the temperature parameter as being 27 degrees celsius
(80 degrees Fahrenheit) with a confidence level of 5%, then the processor module 102
may determine a plurality of bed profiles, effluent concentration profiles 204 and/or
breakthrough times 206 for a plurality of values that fall within 5% of 27 degrees
celsius (80 degrees Fahrenheit). These plural bed profiles, effluent concentration
profiles 204 and/or breakthrough times 206 may be displayed simultaneously at the
output device 108. Alternatively, the processor module 102 determines the bed profile,
effluent concentration profile 204 and/or breakthrough time 206 for the value of the
parameter within the confidence level that provides the safest, or most conservative,
of the various bed profiles, effluent concentration profiles 204 and/or breakthrough
times 206 that are determined using the range of the parameter values that fall within
the confidence level. For example, the processor module 102 may determine that for
a temperature parameter of 27 degrees celsius (80 degrees Fahrenheit) with a confidence
level of 5%, or 24 to 29 degrees celsius (76 to 84 degrees Fahrenheit), the shortest
breakthrough time 206 for a plurality of temperatures between 24 to 29 degrees celsius
(76 and 84 degrees Fahrenheit) occurs at a temperature parameter of 29 degrees celsius
(84 degrees Fahrenheit). In such an example, the processor module 102 communicates
the shortest of the breakthrough times 206 to the output device 108 for presentation
to the user. The processor module 102 thus may determine and the output device 108
may present a conservative bed profile, effluent concentration profile 204 and/or
breakthrough time 206 as a safety limit based on the user's input confidence level.
[0040] The effluent concentration profile 204, the breakthrough time 206 and/or one or more
bed profiles at a plurality of times may be calculated using any of a number of mathematical
models that use one or more of the input parameters described above to determine the
effluent concentration profile 204, the breakthrough time 206 and/or the bed profiles.
For example, in one embodiment, a new model for determining the effluent concentration
profile 204 is employed. This model, referred to as the Ding model, includes two hypotheses
to an adsorption process: (a) for a well-developed, constant-feed, adsorption process,
the dimensionless chemical potential may change exponentially with bed location and
(b) the speed of the concentration wave accelerates with time when the wave evolves
out from the bed. The Ding model may be capable of fitting experimental data over
a wide range of concentrations of several orders of magnitude. The Ding model can
be used as a predictive tool given the adsorption equilibrium and the sensitivities
of the two parameters to certain operating conditions. The Ding model also may be
applied to both adsorptive and reactive processes for air purification processes.
The Ding model may be used to overcome several shortcomings in existing models. For
example, the Ding model may be used to calculate service life at different toxicity
levels, at different feed concentrations, and at different residual life times. The
Ding model may be used to back-estimate an adsorption bed profile at different times
in order to assist in designing filters. The Ding model may more accurately calculate
the effluent concentration profiles and/or breakthrough times of chemical contaminants
having relatively low molecular weights and/or boiling points.
[0041] In one embodiment, the mathematical model that is employed to calculate effluent
concentration profiles and/or breakthrough times is based on a combination of parameters
input by the user (as described above) and physical properties of the chemical contaminants
sought to be filtered. The chemical contaminants may be input by the user, as described
above. The physical properties of the chemical contaminants may be obtained from a
computer-readable storage medium such as one or more of the computer-readable storage
media 110, 112. For example, the computer-readable storage medium 112 may include
a database that stores relevant physical properties of the chemical contaminants input
by the user. The database also can include physical property data on other relevant
chemicals and compounds. For example, the database can store physical property data
on water and atmospheric air. The database of physical property data may be one or
more of a public database, a private database and a custom database. With respect
to a public database, the database may be a publicly accessible database available
over the Internet. A private database may be a database that is accessible by a limited
number of users. For example, the private database can be a database that is available
over an intranet that is accessible only by those users that are authenticated through
a login and password procedure. A custom database can be a database that obtains physical
property data from a public and/or private database but that organizes and/or filters
the data in a customized manner, for example.
[0042] For example, a database may include one or more properties for each chemical contaminant
that could be selected by the user. These properties include, but are not limited
to, one or more of a Chemical Abstracts Service ("CAS") registry number, a chemical
formula, a molecular weight, a liquid density (in grams per cubic centimeter, for
example), a molar polarity (in Pe, for example), a water solubility, a vapor model
(Model 0 or Model 1, for example), one or more of vapor models A, B and C, a chemical
name, a nickname or alias, an Immediately Dangerous to Life and Health ("IDLH") limit
(in parts per million, for example), a Recommended Exposure Limit ("REL") (in parts
per million, for example), a Permissible Exposure Limit ("PEL") (in parts per million,
for example), a Threshold Limit Value ("TLV") (in parts per million, for example),
and a comment. The comment can include any additional relevant information. In one
embodiment, Model 0 of the vapor model may be a vapor model of the Antoine format
and described by the following equation:

Model 1 of the vapor model may be a vapor model of the Antoine format and described
by the following equation:

The properties of the chemicals may be input by an administrator of the system 100.
In one embodiment, one or more of the chemical properties are obtained from the NIST
Web book, available at http://webbook.nist.gov/. One or more of the chemical properties
may be obtained from the NIOSH IDLH guidebook or webpage, available at http://www.cdc.gov/niosh/idlh/intridl4.html.
If a particular property is not available in the database and has not been provided
by the user, the system may issue an audible and/or visual warning to the user.
[0043] The Ding model defines a chemical potential difference of a chemical contaminant
sought to be filtered by a filter cartridge as:

where Φ is the difference between the local chemical potential of the chemical contaminant
in the filter bed of a filter cartridge and the chemical potential of the chemical
contaminant in the feed concentration, or the concentration in the environment in
which the filter cartridge is used;
ϕ is the chemical potential of the chemical contaminant at a given location in the
filter bed;
ϕf is the chemical potential of the chemical contaminant in the feed concentration;
ϕ0 is the chemical potential of the chemical contaminant at the front of the wave, or
the breakthrough curve front, of the chemical contaminant as the chemical contaminant
passes through the filter bed. C
0 is defined as the concentration of the chemical contaminant at the breakthrough curve
front. C* and C
0* are defined as dimensionless variables referenced to the substantially constant
or constant feed concentration (C
f). The chemical potential (
ϕ) may be defined as follows:

[0044] In one embodiment, the breakthrough curve front may be arbitrarily defined so as
to effectively eliminate the effect of any clean regions of the filter bed, or regions
where there is substantially no concentration of the chemical contaminant. In such
an embodiment, a dimensionless position (ζ) of the chemical contaminant and a dimensionless
time (τ) associated with a particular position of the chemical contaminant in the
filter bed may be defined as follows:

where z is a position, or location, in the filter bed expressed in meters; z
0 is the position of the breakthrough curve front in the filter bed expressed in meters;
z
ref is the reference position in the filter bed expressed in meters; t is a time expressed
in seconds; t
0 is the time in seconds at which the breakthrough curve front is located at the position
z
0 in the filter bed; and t
ref is the reference time expressed in seconds. In one embodiment, at the breakthrough
wave front, both the cobra value ζ and the time τ are zero and a concentration (C)
of the chemical contaminant at the breakthrough wave front is C
0, as described above. In this embodiment, at the reference point both the position
(ζ) and the time (τ) are 1 and the concentration (C) is a reference concentration
(C
ref). As the time (τ) increases and approaches infinity (∞), the concentration (C) equals
the reference concentration (C
ref).
[0045] If the filter cartridge remains in the environment that includes the chemical contaminant,
or as the constant feed of the chemical contaminant continues, Φ, or the difference
between the local chemical potential of the chemical contaminant in the filter bed
of a filter cartridge and the chemical potential of the chemical contaminant in the
feed concentration, changes with the position in the filter bed. The change in Φ may
be represented as follows:

where Φ
ref is the difference between the chemical potential of the chemical contaminant in the
filter bed at the reference position and the chemical potential of the chemical contaminant
in the feed concentration.
[0046] When the wave of the chemical contaminant evolves out of the filter bed in the filter
cartridge, the position of the wave may accelerate with respect to time. The speed
at which the wave evolves out of the filter bed may change with respect to time according
to:

where v* is the speed and zeta (

) is an acceleration factor referred to as a "cobra value." Zeta (

) is referred to as the cobra value due to the cobra-like shape of the effluent concentration
profile 204 (shown in Figure 2) for many chemical contaminants. In one embodiment,
waves of chemical contaminants that evolve out of the filter bed at a substantially
constant or decelerated speed (v*) have cobra values (

) that are less than 1, while waves that evolve out of the filter bed with accelerated
speeds (v*) have cobra values (

) that are greater than 1. One or more cobra values (

) may be determined empirically from data or input by the user. For example, at list
of cobra values (

) may be determined from experimental data and stored in one or more of the computer-readable
storage media 110, 112 to be accessed by the processor module 102.
[0047] Accordingly, the position (ζ) of the chemical contaminant may be represented as follows:

Substituting Equation 6 into Equation 4 yields the following relationship:

[0048] Equation 7 is used with the Ding model to represent the general form of a bed profile
and may be used alone or in combination with one or more of the other equations described
herein to generate an effluent concentration profile. For example, the concentration
of chemical contaminants at the end of the filter bed 606 (shown in Figure 6) that
is closest to the port 624 (shown in Figure 6) of the filter cartridge 600 (shown
in Figure 6) may be calculated using the Ding model for a plurality of times. The
concentration of the chemical contaminants at the end of the filter bed 606 may then
be graphed with respect to time to illustrate the concentration of the chemical contaminants
that breakthrough the filter bed 606.
[0049] A stoichiometric time (t
s) of the Ding model can be determined from the following:

[0050] In one embodiment, the reference point used for Equation 7 is arbitrarily defined.
For example, for an arbitrary point 1 in an effluent concentration profile similar
to the effluent concentration profile 204, Equation 8 becomes:

Applying Equation 8, the reference point may be represented in the following:

where the superscript ' denotes a new reference point for the Ding model. Accordingly,
different reference points may be selected for different applications without having
to alter the values of one or more parameters in the Ding model.
[0051] In one embodiment, the Ding model may be used to determine the breakthrough time
206 by determining the effluent concentration profile 204 and comparing the effluent
concentration profile 204 to a breakthrough concentration input by the user. For example,
once an effluent concentration profile 204 is created by the processor module 102,
the time at which the breakthrough concentration occurs in the effluent concentration
profile 204 can be the breakthrough time 206. Alternatively, the Ding model may be
used to directly calculate the breakthrough time 206. For example, the reference point
described above may be set to be equal to the stoichiometric center defined in Equation
9 so that the breakthrough time 206 may be defined as:

where q represents the loading of the chemical contaminant(s) in the filter bed,
or the adsorption equilibrium, expressed in moles per kilogram; p
b represents the density of the filter particles in the filter bed, expressed in kilograms
per cubic meters; V represents the volume of the filter bed, expressed in cubic meters;
F represents the flowrate of the chemical contaminant(s) through the filter bed, expressed
in cubic meters per second; t
r represents the breakthrough time 206, or the residence time; and Λ represents a separation
ratio that is calculated at the feed concentration C
f. The value of the adsorption equilibrium (q) may be calculated from experimental
data, simulated isotherm models, or input by the user. From Equation 12, the separation
ratio (Λ) and the breakthrough time 206 (t
r) may be determined using the following equations:

[0052] Alternatively, one or more other mathematical models other than the Ding model described
above may be used to determine one or more of a bed profile, the effluent concentration
profile 204 and the breakthrough time 206. For example, one or more of the models
described in
Wood, Gerry O., Estimating Service Lives of Organic Vapor Cartridges, American Industrial
Hygiene Association Journal (Jan. 1994), pp. 11-15;
Wood, Gerry O., Moyer, Ernest S.; A Review of the Wheeler Equation and Comparison
of Its Applications to Organic Vapor Respirator Cartridge Breakthrough Data, Am. Ind.
Hyg. Assoc. J. 50(8): 400-407 (1989);
Wood, Gerry O., Estimating Service Lives of Air-Purifying Respirator Cartridges for
Reactive Gas Removal, J. of Occupational and Environmental Hygiene, 2:414-423 (2005);
Wood, Gerry O., Organic Vapor Respirator Cartridge Breakthrough Curve Analysis, J.
of the International Society for Respiratory Protection, Winter 1992-1993 (collectively referred to as the "Wood model") may be used.
[0053] In one embodiment, one or more of the variables described above in connection with
Equations 1 through 14 may be input into the processor module 102 by the user at the
user interface 106. Alternatively, one or more of these variables may be obtained
by the processor module 102 from one or both of the computer-readable storage media
110, 112. For example, a default value for a variable may be obtained from the computer-readable
storage medium 110, as described above. In one embodiment, the processor module 102
may acquire data on the chemical contaminants from a public, private and/or custom
database instead of requiring the user to input this data, as described above.
[0054] In the cartridge selection mode, the processor module 102 obtains or receives one
or more parameters to determine a recommended filter cartridge. In one embodiment,
the processor module 102 also may determine one or more of the effluent concentration
profile 204 and the breakthrough time 206, as described above. The recommended filter
cartridge is a filter cartridge that is recommended for a user to use based on the
input parameters. The input parameters used by the processor module 102 in the cartridge
selection mode include, but are not limited to, one or more cartridge selection parameters.
One or more of the use condition parameters also may be used as input parameters.
The cartridge selection parameters include data or information relevant to the usefulness
or utility of a filter cartridge to the user. For example, the cartridge selection
parameters may include, but are not limited to, one or more of a minimum service life,
a comfort indicator, a price, an empirical result, an inventory, a regional requirement,
a phasing out indication, a phasing out indication, and a flexibility of use parameter.
[0055] The minimum service life parameter includes the minimum service life of a filter
cartridge that is desired to be used. For example, the user may input a minimum service
life that the user requires for any filter cartridge that will be recommended by the
processor module 102. The processor module 102 may use the minimum service life to
eliminate one or more filter cartridges from a listing of all possible filter cartridges.
For example, based on the minimum service life and one or more use condition parameters,
the processor module 102 may determine the breakthrough time 206 for several filter
cartridges do not meet or exceed the minimum service life input by the user. These
filter cartridges are eliminated from the list of possible cartridges to recommend
to the user. The minimum service life may be input as an amount of time or as a range
of acceptable service life times. The minimum service life may be input using the
user interface 106 and communicated to the processor module 102 as the input 104.
[0056] The comfort indicator includes information related to the ease of use of a filter
cartridge. For example, the comfort indicator may be expressed as a weight of a filter
cartridge and/or an inhalation resistance of a filter cartridge. The user may input
the comfort indicator as a maximum weight and/or a maximum inhalation resistance of
the filter cartridge that will be recommended by the processor module 102. The processor
module 102 may use the comfort indicator(s) to eliminate one or more filter cartridges
from a listing of all possible filter cartridges. For example, based on the maximum
weight and/or maximum inhalation resistance, the processor module 102 may eliminate
several filter cartridges from the list of possible cartridges to recommend to the
user. The eliminated filter cartridges may have a weight that exceeds the maximum
filter weight and/or an inhalation resistance that exceeds the maximum inhalation
resistance. The comfort indicator can be input using the user interface 106 and communicated
to the processor module 102 as the input 104.
[0057] The price parameter includes the cost to the user of a filter cartridge. For example,
the price may be the current market cost to purchase a filter cartridge. The user
may input the price as a maximum cost of the filter cartridge that will be recommended
by the processor module 102. The processor module 102 may use the price to eliminate
one or more filter cartridges from a listing of all possible filter cartridges. For
example, based on the maximum cost input by the user, the processor module 102 may
eliminate several filter cartridges from the list of possible cartridges to recommend
to the user. The eliminated filter cartridges may have a cost that exceeds the maximum
cost input by the user. The price can be input using the user interface 106 and communicated
to the processor module 102 as the input 104.
[0058] The empirical result includes a recommendation of a filter cartridge to the user
based on a previous recommendation of a filter cartridge based on one or more common
input parameters. A plurality of empirical results from previous filter cartridge
recommendations based on corresponding input parameters may be stored in the computer-readable
storage medium 110 and/or 112 as a database or table, for example. The processor module
102 may query the database or table to determine if one or more cartridge selection
parameters input by the user correspond to the cartridge selection parameters previously
input by another user. If a sufficient number of cartridge selection parameters from
a previous filter cartridge recommendation are substantially similar to the cartridge
selection parameters currently input by the user, the processor module 102 may recommend
the same filter cartridge as was previously recommended. In one embodiment, the number
of common cartridge selection parameters that is required before a filter cartridge
is recommended based on an empirical result can be modified by the user.
[0059] The inventory parameter includes an amount of available filter cartridges. For example,
one or more filter cartridges that could be recommended to the user by the processor
module 102 may be out of stock or otherwise unavailable. The processor module 102
may consider the inventory of available filter cartridges and remove the filter cartridges
that are out of stock from the list of all filter cartridges to recommend to the user.
In doing so, the processor module 102 avoids recommending an unavailable filter cartridge
to the user. The processor module 102 may access the inventory of available filter
cartridges from a database or list of available filter cartridges stored at one or
more of the computer-readable storage media 110, 112.
[0060] The regional requirement parameter includes a regional filter cartridge requirement.
For example, various governments and/or jurisdictions may have varied minimum requirements
for filter cartridges. These minimum requirements may be stored in one or more of
the computer-readable storage media 110, 112 and accessible to the processor module
102. The processor module 102 may access relevant regional requirements to eliminate
one or more filter cartridges from set of available filter cartridges. For example,
one or more filter cartridges may not meet or exceed the requirements of a particular
jurisdiction. The processor module 102 may eliminate these filter cartridges from
the list of possible filter cartridges to recommend to the user. In one embodiment,
the processor module 102 may determine regional requirements for the user by obtaining
the Internet Protocol ("IP") address of the user. For example, the processor module
102 may obtain the IP address of the user interface 106 employed by the user to input
the cartridge selection parameters. Based on this IP address, the processor module
102 can determine what regional requirements may apply to the user and eliminate any
filter cartridges that do not meet or exceed these regional requirements.
[0061] The phasing out indication includes an indication that one or more filters are in
the process of being removed from the market. For example, a filter cartridge may
be associated with data that indicates that the filter cartridge is no longer being
manufactured and the existing inventory of the filter cartridge is the remaining inventory
of the filter cartridge. The phasing out indications for the filter cartridges may
be stored in a list, table or database stored in one or more of the computer-readable
storage media 110, 112. The processor module 102 may consider the phasing out of available
filter cartridges and remove the filter cartridges that are being phased out from
the list of all filter cartridges to recommend to the user. In doing so, the processor
module 102 avoids recommending a filter cartridge that is being phased out to the
user.
[0062] The phasing in indication includes an indication that one or more filters are in
the process of being introduced to the market. For example, a filter cartridge may
be associated with data that indicates that the filter cartridge is relatively new
and is being phased in to be used in a particular market or industry. The phasing
in indications for the filter cartridges may be stored in a list, table or database
stored in one or more of the computer-readable storage media 110, 112. The processor
module 102 may consider the phasing in of filter cartridges and recommend only the
filter cartridges that are being phased in.
[0063] The flexibility of use parameter includes an indication of the number of air respirators
that may be able to use a particular filter cartridge. For example, a flexibility
of use parameter may include a number of air respirators with which a filter cartridge
is compatible. Alternatively, the flexibility of user parameter may be a relative
indication of how many air respirators may use a particular filter cartridge. For
example, if a first filter cartridge may be used with more air respirators than a
second filter cartridge, then the first filter cartridge may be associated with a
larger flexibility of use parameter than the second filter cartridge. The flexibility
of use parameter may be associated with each of a plurality of filter cartridges in
a list, table, database, and the like, in one or more of the computer-readable storage
media 110, 112, for example.
[0064] In the cartridge selection mode, the processor module 102 receives one or more of
the cartridge selection parameters and, based on the parameters recommends one or
more filter cartridges to the user. For example, the processor module 102 may access
a list of filter cartridges from the computer-readable storage medium 110 and/or 112.
Based on the cartridge selection parameters input by the user and/or accessed by the
processor module 102, the processor module 102 eliminates one or more filter cartridges
from the list of filter cartridges. The processor module 102 may recommend one or
more filter cartridges that remain in the list after eliminating those filter cartridges
that do not meet the parameters input by the user. In one embodiment, the processor
module 102 also receives one or more use condition parameters. The processor module
102 may employ the use condition parameters to determine the breakthrough time 206
of one or more filters in the list. The processor module 102 may recommend only those
filters that meet the criteria set forth in the cartridge selection parameters and
have a sufficiently great breakthrough time 206. The sufficiently great breakthrough
time 206 may be a minimum breakthrough time, for example
[0065] In one embodiment, the processor module 102 does not recommend a filter cartridge
until a minimum number or amount of the cartridge selection parameters and/or use
condition parameters are received by the processor module 102. For example, the processor
module 102 may not determine a recommended filter cartridge until at least one cartridge
selection parameter, the cartridge type, the chemical contaminant(s) and the chemical
concentration(s) are accessible and/or received by the processor module 102.
[0066] The processor module 102 communicates the recommended filter cartridge(s) (or data
representative of the recommended filter cartridge(s)) to the output device 108 as
the output 120. The output device 108 provides the recommended filter cartridge(s)
to the user. For example, the output device 108 may display an image of a recommended
filter cartridge to the user. In one embodiment, the processor module 102 determines
a recommended filter cartridge and the output device 108 presents the same to a user.
The user may then alter, change or add to the parameters input to the processor module
102. The processor module 102 then determines if the recommended filter cartridge
needs to be updated. If so, the processor module 102 provides an updated filter cartridge
recommendation and the output device 108 presents the same to the user. For example,
the user may change the parameters input to the processor module 102 and the processor
module 102 dynamically changes or updates the recommended filter cartridge in response
thereto.
[0067] Figure 2 is an illustration of a graphical user interface 200 used to enter one or
more parameters into the system 100 shown in Figure 1 and to display output 120 (shown
in Figure 1) to a user according to one embodiment. The graphical user interface 200
may be displayed to a user at the output device 108 (shown in Figure 1). The user
employs an input device at the user interface 106 (shown in Figure 1) to manipulate
one or more buttons, slides, menus, lists, and the like in the graphical user interface
200. While Figure 2 illustrates one embodiment of a graphical user interface for submitting
the input 104 (shown in Figure 1) to the processor module 102, other embodiments of
graphical user interfaces with different layouts and graphical presentations are possible.
[0068] The graphical user interface 200 includes a graph window 202. In the illustrated
embodiment, the graph window 202 displays the effluent concentration profile 204 and
the breakthrough time 206. The effluent concentration profile 204 may be represented
as a plot of data in a graph defined by a time axis 208 and a concentration axis 210.
The breakthrough time 206 may be represented on the same graph. The data used to generate
the effluent concentration profile 204 may be created by the processor module 102
(shown in Figure 1) based on a mathematical model and one or more parameters input
by the user, as described above. The breakthrough time 206 may be determined by the
processor module 102 by calculating a breakthrough concentration 212 and determining
the time at which the effluent concentration profile 204 exceeds the breakthrough
concentration 212. The breakthrough concentration 212 may be input by the user or
may be obtained from one or more of the computer-readable storage media 110, 112 (shown
in Figure 1). For example, the breakthrough concentration 212 may be based on, or
substantially similar to, the occupational exposure limit and/or the particulate protection
level input by the user, as described above.
[0069] A summary window 214 provides a summary of the parameters input by the user and/or
the breakthrough time 206 calculated by the processor module 102 in one embodiment.
For example, the summary window 214 may list the breakthrough time 206, the chemical
contaminant input by the user, and the chemical concentration input by the user.
[0070] A user can input one or more parameters described above into a plurality of parameter
windows 216, 218, 220, 222. In the illustrated embodiment, the user can input the
ambient pressure in the parameter window 216, the breathing rate in the parameter
window 218, the ambient temperature in the parameter window 220, and the relative
humidity in the parameter window 222. The user may use a keyboard, stylus, and the
like to textually input the parameters into the parameter windows 216, 218, 220, 222
and/or may select a value for a parameter from a drop down menu. For example, the
parameter window 218 can provide a drop down menu for a user to select a breathing
rate. The user can select a variance to one or more of the parameters input in the
parameter window 216, 218, 220, 222 in one or more of the variance windows 224, 226,
228, 230. For example, the user can input a percentage in one of the variance windows
224, 226, 228, 230 to indicate an acceptable variance for a parameter in a corresponding
parameter window 216, 218, 220, 222. In one embodiment, the confidence value associated
with the corresponding input parameter is input by the user using the variance windows
224, 226, 228, 230. For example, the user may input a confidence value of 5% in the
variance window 224 for the ambient pressure parameter that is input in the parameter
window 216, a confidence value of 10% in the variance window 226 for the breathing
rate parameter that is input in the parameter window 218, a confidence value of 10%
in the variance window 228 for the temperature parameter that is input in the parameter
window 220, and a confidence value of 5% in the variance window 230 for the humidity
parameter that is input in the parameter window 222, as shown in the illustrated embodiment.
One or more slider bars 232, 234, 236, 238 may be moved or manipulated by the user
to change a corresponding parameter value that is input in the parameter windows 216,
218, 220, 222.
[0071] The filter cartridge recommendation 240 is presented to the user on the graphical
user interface 200 in one embodiment. As described above, the filter cartridge recommendation
240 includes a recommended filter cartridge selected by the processor module 102 (shown
in Figure 1) based on one or more input parameters from the user. In one embodiment,
the filter cartridge recommendation 240 can be presented as an image of the recommended
filter cartridge, as shown in the illustrated embodiment. Alternatively, the filter
cartridge recommendation 240 may include one or more images of one or more filter
cartridges selected by a user. A filter cartridge label 242 may be displayed on the
graphical user interface 200 in one embodiment. For example, an image of the filter
cartridge label 242 that corresponds to the filter cartridge recommendation 240 may
be displayed on the graphical user interface 200. Alternatively, the filter cartridge
label 242 may include one or more images of one or more labels for filter cartridges
selected by a user.
[0072] A cartridge list window 244 provides a list of filter cartridges that are selectable
by the user in one embodiment. The user may select one or more filter cartridges from
the cartridge list window 244. For example, the user may input the cartridge type
parameter described above by selecting one or more cartridges provided in the cartridge
list window 244. The filter cartridges listed in the cartridge list window 244 may
be limited based on one or more of the cartridge selection parameters input by a user,
as described above.
[0073] A contaminant list window 246 provides a list of chemical contaminants that are selectable
by the user in one embodiment. The user may select one or more chemical contaminants
from the contaminant list window 246. For example, the user may input the chemical
contaminant parameter described above by selecting one or more chemical contaminants
provided in the contaminant list window 246.
[0074] In one embodiment, a contaminant search window 248 allows the user to type in one
or more chemical contaminants so that the processor module 102 searches for a corresponding
chemical contaminant. For example, instead of reviewing a list of chemical contaminants
provided in the contaminant list window 246, the user may type in the name of a chemical
contaminant in the contaminant search window 248 to input the chemical contaminant
parameter to the processor module 102.
[0075] A chemical concentration window 250 allows the user to input the chemical concentration
parameter described above. The user may input an acceptable variance for the chemical
concentration parameter using a variance window 254. In one embodiment, the user inputs
a confidence value in the variance window 254, similar to as described above with
respect to the variance windows 224, 226, 228, 230. For example, the user may input
a confidence value of 0% in the variance window 254 that corresponds to the chemical
concentration parameter that is input in the chemical concentration window 250. A
breakthrough concentration window 252 allows the user to input the breakthrough concentration
212 described above. One or both of the chemical concentration parameter and the breakthrough
concentration 212 may be adjusted by the user by sliding one or both of slider bars
256, 258.
[0076] As described above, once the processor module 102 (shown in Figure 1) has determined
the effluent concentration profile 204, the breakthrough time 206 and/or the recommended
filter cartridge 240 based on input parameters from the user, the processor module
102 may dynamically update one or more of the effluent concentration profile 204,
the breakthrough time 206 and the recommended filter cartridge 240 if the user changes
or updates one or more of the input parameters. For example, if the user changes the
chemical contaminant parameter by selecting a different chemical contaminant in the
contaminant list window 246, the processor module 102 receives the updated chemical
contaminant parameter and, if necessary, updates the effluent concentration profile
204, the breakthrough time 206 and/or the recommended filter cartridge 240 based on
the updated chemical contaminant parameter.
[0077] Figure 3 is an illustration of a graphical user interface 300 used to enter one or
more parameters into the system 100 shown in Figure 1 according to one embodiment.
Similar to the graphical user interface 200 (shown in Figure 2), the graphical user
interface 300 may be displayed to a user at the output device 108 (shown in Figure
1). The user employs an input device at the user interface 106 (shown in Figure 1)
to manipulate one or more buttons and slides, and the like, in the graphical user
interface 300. While Figure 3 illustrates one embodiment of a graphical user interface
for submitting the input 104 (shown in Figure 1) to the processor module 102, other
embodiments of graphical user interfaces with different layouts and graphical presentations
are possible.
[0078] The graphical user interface 300 includes a plurality of slider bars 302, 304, 306,
308 that are manipulated by the user to input one or more of the parameters described
above. For example, the user may employ an input device such as a mouse at the user
interface 106 (shown in Figure 1) to move one or more of the slider bars 302, 304,
306, 308 to a position that corresponds to one or more input parameters. In the illustrated
embodiment, the user can move the slider bar 302 to input the minimum service life
parameter described above. For example, the user can move the slider bar 302 to the
right in the graphical user interface 300 to indicate that the minimum service life,
or breakthrough time, of a filter cartridge that is to be recommended by the processor
module 102 is relatively important to the user. Conversely, the user can move the
slider bar 302 to the left to indicate that the minimum service life, or breakthrough
time, of a filter cartridge that is to be recommended by the processor module 102
is relatively unimportant to the user. The movement of the slider bar 302 is communicated
to the processor module 102 as the input 104. The processor module 102 receives the
minimum service life parameter input using the slider bar 302 and may limit the list
of filter cartridges that are to be recommended to the user as the recommended filter
cartridge 240 (shown in Figure 2) in response thereto. For example, if the user employs
the slider bar 302 to indicate that the minimum service life of a filter cartridge
is relatively important, then the processor module 102 may limit the possible filter
cartridges that may be recommended to those filter cartridges with relatively long
service lives. On the other hand, if the user employs the slider bar 302 to indicate
that the minimum service life of a filter cartridge is relatively unimportant, then
the processor module 102 may not limit the possible filter cartridges that may be
recommended based on the service lives of the filter cartridges. Alternatively, instead
of indicating the relative importance of a filter cartridge's service life using the
slider bar 302, the slider bar 302 may be used to input a minimum service life. For
example, the slider bar 302 may be manipulated by the user to input a minimum service
life in terms of minutes, hours, or days. Optionally, another input mechanism other
than the slider bar 302 is used to input the minimum service life parameter. For example,
a window similar to the windows 216 through 222 may be used.
[0079] The slider bar 304 can be employed to input the comfort indicator described above.
For example, the user can move the slider bar 304 to the right in the graphical user
interface 300 to indicate that the comfort indicator of a filter cartridge that is
to be recommended by the processor module 102 is relatively important to the user.
Conversely, the user can move the slider bar 304 to the left to indicate that the
comfort indicator of a filter cartridge that is to be recommended by the processor
module 102 is relatively unimportant to the user. In one embodiment, the comfort indicator
may be expressed as one or more of the weight and inhalation resistance of a filter
cartridge. The movement of the slider bar 304 is communicated to the processor module
102 as the input 104. The processor module 102 receives the comfort indicator input
using the slider bar 304 and may limit the list of filter cartridges that are to be
recommended to the user as the recommended filter cartridge 240 (shown in Figure 2)
in response thereto. For example, if the user employs the slider bar 304 to indicate
that the comfort indicator of a filter cartridge is relatively important, then the
processor module 102 may limit the possible filter cartridges that may be recommended
to those filter cartridges with relatively low weights and/or low inhalation resistances.
On the other hand, if the user employs the slider bar 304 to indicate that the comfort
indicator of a filter cartridge is relatively unimportant, then the processor module
102 may not limit the possible filter cartridges that may be recommended based on
the weight and/or inhalation resistance of the filter cartridges. Alternatively, instead
of indicating the relative importance of a filter cartridge's comfort indicator using
the slider bar 304, the slider bar 304 may be used to input a comfort indicator. For
example, the slider bar 304 may be manipulated by the user to input a maximum weight
and/or inhalation resistance of a filter cartridge. Optionally, another input mechanism
other than the slider bar 304 is used to input the comfort indicator. For example,
a window similar to the windows 216 through 222 may be used.
[0080] The slider bar 306 can be employed to input the cost parameter described above. For
example, the user can move the slider bar 306 to the right in the graphical user interface
300 to indicate that the price of a filter cartridge that is to be recommended by
the processor module 102 is relatively important to the user. Conversely, the user
can move the slider bar 306 to the left to indicate that the price of a filter cartridge
that is to be recommended by the processor module 102 is relatively unimportant to
the user. The movement of the slider bar 306 is communicated to the processor module
102 as the input 104. The processor module 102 receives the cost parameter input using
the slider bar 306 and may limit the list of filter cartridges that are to be recommended
to the user as the recommended filter cartridge 240 (shown in Figure 2) in response
thereto. For example, if the user employs the slider bar 306 to indicate that the
price of a filter cartridge is relatively important, then the processor module 102
may limit the possible filter cartridges that may be recommended to those filter cartridges
with relatively low prices. On the other hand, if the user employs the slider bar
306 to indicate that the price of a filter cartridge is relatively unimportant, then
the processor module 102 may not limit the possible filter cartridges that may be
recommended based on the price of the filter cartridges. Alternatively, instead of
indicating the relative importance of a filter cartridge's price using the slider
bar 306, the slider bar 306 may be used to input a price in an amount of currency.
For example, the slider bar 306 may be manipulated by the user to input a maximum
price of a filter cartridge. Optionally, another input mechanism other than the slider
bar 306 is used to input the cost parameter. For example, a window similar to the
windows 216 through 222 may be used.
[0081] The slider bar 308 can be employed to input the flexibility of use parameter described
above. For example, the user can move the slider bar 308 to the right in the graphical
user interface 300 to indicate that the flexibility of use of a filter cartridge that
is to be recommended by the processor module 102 is relatively important to the user.
Conversely, the user can move the slider bar 308 to the left to indicate that the
flexibility of use parameter of a filter cartridge that is to be recommended by the
processor module 102 is relatively unimportant to the user. The movement of the slider
bar 308 is communicated to the processor module 102 as the input 104. The processor
module 102 receives the flexibility of use parameter input using the slider bar 308
and may limit the list of filter cartridges that are to be recommended to the user
as the recommended filter cartridge 240 (shown in Figure 2) in response thereto. For
example, if the user employs the slider bar 308 to indicate that the flexibility of
use parameter of a filter cartridge is relatively important, then the processor module
102 may limit the possible filter cartridges that may be recommended to those filter
cartridges with a relatively high flexibilities of use. For example, the processor
module 102 may limit the possible filter cartridges to those filter cartridges that
may be used with the most different air respirators. On the other hand, if the user
employs the slider bar 308 to indicate that the flexibility of use parameter of a
filter cartridge is relatively unimportant, then the processor module 102 may not
limit the possible filter cartridges that may be recommended based on the flexibility
of use of the filter cartridges. Alternatively, instead of indicating the relative
importance of a filter cartridge's flexibility of use using the slider bar 308, the
slider bar 308 may be used to input a flexibility of use parameter in terms of a minimum
number of air respirators with which the recommended filter cartridge 240 (shown in
Figure 2) must be compatible. Optionally, another input mechanism other than the slider
bar 308 is used to input the flexibility of use parameter. For example, a window similar
to the windows 216 through 222 may be used.
[0082] Figure 4 is a flowchart for a method 400 of determining at least one of an effluent
concentration profile, a breakthrough time and a filter cartridge recommendation.
At block 402, one or more input parameters are received. For example, one or more
use condition parameters, site condition parameters, and cartridge selection parameters
are input by a user into the user interface 106 and communicated as input 104 to the
processor module 102. At block 404, one or more of the input parameters are employed
to determine one or more of the effluent concentration profile, the breakthrough time
and the filter cartridge recommendation. For example, the Ding model described above
may be used to calculate the effluent concentration profile 204 (shown in Figure 2)
and the breakthrough time 206 (shown in Figure 2), as described above. At block 406,
one or more of the effluent concentration profile, the breakthrough time and the filter
cartridge recommendation are displayed to the user. For example, an image of the filter
cartridge recommendation 240 (shown in Figure 2) may be displayed to the user at the
output device 108. At block 408, a decision is made as to whether any of the parameters
received at block 402 have been updated and/or whether any additional parameters have
been received. If one or more parameters have been updated or one or more additional
parameters have been received, the method 400 proceeds between block 408 and block
410. If no parameters have been updated or no more parameters have been received,
the method 400 terminates. At block 410, an updated effluent concentration profile,
breakthrough time and/or filter cartridge recommendation is determined. For example,
a change or update to one or more parameters, or the addition of more parameters,
may impact the effluent concentration profile, the breakthrough time and/or the filter
cartridge recommendation that is determined at block 404. The updated and/or additional
parameter(s) are factored in and employed to determine the updated effluent concentration
profile, breakthrough time and/or filter cartridge recommendation at block 410. At
block 412, the updated effluent concentration profile, breakthrough time and/or filter
cartridge recommendation is displayed. For example, an updated plot of the effluent
concentration profile and/or breakthrough time may be displayed on the output device
108. The method 400 proceeds between block 412 and block 408.
[0083] Figure 5 illustrates a block diagram of exemplary manners in which one or more embodiments
described herein may be stored, distributed and installed on computer-readable medium.
In Figure 5, the "application" represents one or more of the methods and process operations
discussed above. For example, the application may represent the process carried out
in connection with FIG. 4 as discussed above.
[0084] As shown in Figure 5, the application is initially generated and stored as source
code 502 on a source computer-readable medium 504. The source code 502 is then conveyed
over path 506 and processed by a compiler 508 to produce object code 510. The object
code 510 is conveyed over path 512 and saved as one or more application masters on
a master computer-readable medium 514. The object code 510 is then copied numerous
times, as denoted by path 516, to produce production application copies 518 that are
saved on separate production computer-readable medium 520. The production computer-readable
medium 520 is then conveyed, as denoted by path 522, to various systems, devices,
terminals and the like. In the example of Figure 5, a user terminal 524, a device
526 and a system 528 are shown as examples of hardware components, on which the production
computer-readable medium 520 are installed as applications (as denoted by 530, 532,
534).
[0085] The source code may be written as scripts, or in any high-level or low-level language.
Examples of the source, master, and production computer-readable medium 502, 514 and
520 include, but are not limited to, CDROM, RAM, ROM, Flash memory, RAID drives, memory
on a computer system and the like. Examples of the paths 506, 512, 516, and 522 include,
but are not limited to, network paths, the internet, Bluetooth, GSM, infrared wireless
LANs, HIPERLAN, 3G, satellite, and the like. The paths 506, 512, 516, and 522 also
may represent public or private carrier services that transport one or more physical
copies of the source, master, or production computer-readable medium 502, 514 or 520
between two geographic locations. The paths 506, 512, 516, and 522 may represent threads
carried out by one or more processors in parallel. For example, one computer may hold
the source code 502, compiler 508 and object code 510. Multiple computers may operate
in parallel to produce the production application copies 518. The paths 506, 512,
516, and 522 may be intra-state, inter-state, intra-country, inter-country, intra-continental,
inter-continental and the like.
[0086] The operations noted in Figure 5 may be performed in a widely distributed manner
world-wide with only a portion thereof being performed in the United States. For example,
the application source code 502 may be written in the United States and saved on a
source computer-readable medium 504 in the United States, but transported to another
country (corresponding to path 506) before compiling, copying and installation. Alternatively,
the application source code 502 may be written in or outside of the United States,
compiled at a compiler 508 located in the United States and saved on a master computer-readable
medium 514 in the United States, but the object code 510 transported to another country
(corresponding to path 516) before copying and installation. Alternatively, the application
source code 502 and object code 510 may be produced in or outside of the United States,
but production application copies 518 produced in or conveyed to the United States
(for example, as part of a staging operation) before the production application copies
518 are installed on user terminals 524, devices 526, and/or systems 528 located in
or outside the United States as applications 530, 532, 534.
[0087] As used throughout the specification and claims, the phrases "computer-readable medium"
and "instructions configured to" shall refer to any one or all of i) the source computer-readable
medium 504 and source code 502, ii) the master computer-readable medium and object
code 510, iii) the production computer-readable medium 520 and production application
copies 518 and/or iv) the applications 530, 532, 534 saved in memory in the terminal
524, device 526 and system 528.