Field of the Invention
[0001] The present invention relates to methods of sanitizing wetted systems, such as building
plumbing systems, and also the devices used in such sanitizing processes.
Background of the Invention
[0002] Water carrying systems are utilised in a wide range of situations, ranging from a
building's plumbing system to beer brewing equipment. In general use the constant
flow of water through these systems prevents the build-up of unwanted bacteria and
other waterborne pathogens.
[0003] However when underused or left idle for a time these 'wetted' systems are prone to
outbreaks of colonies of waterborne pathogen, examples of which include Legionella
and Pseudomonas. If these pathogen colonies are allowed to proliferate they can bring
with them to risk of infections and even fatalities when the water system is used
after a period of non-use.
[0004] In addition to the clear health risks, the proliferation of waterborne pathogens,
examples of which include viruses, bacteria, parasites and other microbial entities,
can lead to the formation of biofilms on the internal surfaces of water carrying systems.
Biofilm growing within water systems reduces water quality and the efficacy of sensitive
equipment connected to the water system. This issue can effect a wide range of sensitive
equipment, ranging from dialysis machines to fluid flow meters.
[0005] Under current practises, the proliferation of bacteria and other pathogens in wetted
systems is achieved by the regular flushing of water through the systems and by the
use of disinfectants. Although effective, these approaches are not environmentally
friendly due to the levels of waste water, some of which may contain chemical disinfectant,
that need to be disposed of.
Summary of the Invention
[0006] In the light of the environmental issues associated with both the build-up of bacteria
in wetted systems and also the current processes used to counter pathogen proliferation,
the present invention provides a method of sanitizing a wetted system according to
claim 1.
[0007] In this regard, there is provided a method of sanitizing a wetted system by inducing
the movement of a gas through pipes and fixtures of said system to dry out the internal
surfaces and structures of the system, and wherein the gas movement is achieved by
blowing the gas into and through the pipes and fixtures of said system and/or sucking
the gas through and out of the pipes and fixtures of said system.
[0008] In the method of the present invention, a suitable gas can be blown and/or sucked
through the pipes and fixtures that make up the water system so as to achieve a drying
effect on the internal surfaces of the pipes and fixtures where residual water would
otherwise accumulate and, in so doing, provide an environment for bacteria to thrive.
[0009] In view of this, in its broadest application, the sanitizing method of the present
invention could usefully be employed in any wetted systems that are left dormant for
a noticeable period of time (i.e. long enough to allow bacteria to establish a colony).
[0010] With that said, the method of the present invention is considered particularly suitable
for sanitizing the plumbing systems of buildings where the water system may be subjected
to initial pressure testing after construction/repair and then left idle for a period.
It is envisioned that this situation would not be uncommon in newly constructed buildings,
for example.
[0011] Although the method of the present invention might be usefully employed in entire
wetted systems it is also envisaged that the approach may be applied to limited sections
of wetted systems (e.g. hot water tanks of domestic and commercial plumbed systems).
Also, the method may be employed on a range of systems that typically have inaccessible
pipework, examples of which range from hot tubs and closed circuit systems such as
endoscope washers.
[0012] It is appreciated that a range of gases may be suitably used in the method of the
present invention. However, preferably the gas may be selected from a group consisting
of: air, carbon dioxide, nitrogen, ozone (O
3) and other inert gases.
[0013] It is envisioned that inducing the movement of a gas within the pipes and fixtures
of a wetted system will not only achieve a drying effect on any standing water in
the system, it will also help to extract accumulated pathogenic materials from within
the system.
[0014] Preferably the movement of the gas within the wetted system may comprise a one-way
flow of gas. This could be achieved by sucking or blowing the gas from a single port
in the system. This could also be achieved by blowing gas from a first port in a first
location in the system and sucking gas from a second port in a second location in
the system.
[0015] Alternatively, the movement of gas within the wetted system may comprise a tidal
flow of gas. In the case of a tidal flow, gas is periodically blown into the system
and then sucked out again in a manner similar to that of the human lungs.
[0016] Preferably the gas may be heated before it enters the wetted system. In this way
the drying effects of the gas as it moves through the pipes and fixtures of the system
is increased. Further preferably the temperature of the gas entering the system may
be in the range of 1 to 100 degrees C.
[0017] Preferably the gas may be dehumidified before it enters the wetted system. Reducing
the moisture content of the gas also serves to increase the drying effect of the gas
as it moves through the pipes and fixtures of the system.
[0018] Preferably the gas may be filtered prior to entering the wetted system and/or after
it leaves the system. In this way it is possible to prevent contamination or environmental
ingress into the system and/or the release into the environment of harmful bacteria
extracted from the wetted system by the gas flow.
[0019] Preferably the flow rate of gas leaving the system may be monitored. By monitoring
the flow rate it is possible to adjust the extent to which the gas is blown into and/or
sucked out of the system.
[0020] Preferably the humidity of the gas leaving the system is monitored. Further preferably
the humidity level of the gas may be used to adjust the extent to which the gas is
dehumidified and/or heating before it enters the wetted system.
[0021] Monitoring the characteristics of the gas as it leaves the wetted system is particularly
relevant in embodiments where a gas flow is recirculated within the system, which
may be in the case in both a one-way gas flow and a tidal gas flow.
[0022] Preferably the method of the present invention further comprises the step of installing
at least one port in the system to facilitate the blowing and/or sucking of the gas
through the system.
[0023] It is envisioned that in some situations where the wetted system does have a suitable
inlet/outlet available it may be necessary to install at least one port on the system
that is capable of forming a gas tight seal with a wetted system sanitization device
so that the device can induce the movement of gas by blowing/sucking gas through the
system. It is further envisioned that the port may take the form of an adaptor that
is securely connectable to an existing inlet/outlet of the system.
[0024] Preferably the method of the present invention may further comprise the step of adding
a biocide to the gas before it enters the system. It is envisioned the delivering
a biocide along with the gas helps to neutralise bacteria within the system at the
same time as they are being dried out and extracted by the movement of gas through
the pipes and fixtures.
[0025] Preferably the movement of gas through the wetted system can be achieved using pumping
means. Alternatively, the movement of gas may be achieved using a compressed gas source
to blow gas through the system.
[0026] Preferably the method of the present invention may be used to sanitize a building
plumbing system.
[0027] In another aspect of the present invention there is provided a wetted system sanitization
device for use in accordance with the method of the present invention, said device
comprising: attachment means configured to form a gas tight connection with a wetted
system; actuation means configured to move gas through the wetted system via said
attachment means.
[0028] Preferably the actuation means may comprise a pump. Alternatively the actuation means
may comprise a compressed gas source, such as a gas canister.
[0029] Preferably the device may further comprise a heater to heat the gas being moved through
the wetted system.
[0030] Preferably the device may further comprise a dehumidifier to control the humidity
of the gas moving through the wetted system.
[0031] Preferably the device may further comprise one or more filters configured to capture
material extracted from the system by the induced movement of gas.
[0032] It is envisioned that such material would likely include harmful organisms and spores
that might otherwise be released into the environment when the leave the wetted system.
As such, preferably the device may further comprise pathogen containment means to
safely house pathogenic materials recovered from the wetted system.
[0033] Preferably the attachment means are configured to form a closed circuit between the
wetted system and the device. Once again, this is considered beneficial because it
prevents the release of recovered pathogenic materials into the environment.
[0034] Preferably the device may further comprise control means that monitor the rate of
gas flow leaving the wetted system and adjust the operation of the actuation means
accordingly.
[0035] For example, in situations where the flow rate of gas leaving the system is lower
than expected the operation level of the actuation means may be increased to increase
the flow rate. This in turn may help to dislodge blockages (e.g. biofilms) within
the system. In situations where the flow rate is higher than expected (possibly after
the clearance of a blockage) the operation level of the actuation means may be reduced.
[0036] In a further aspect of the present invention there is provided a sanitizing device
adaptor that is configured to connect an existing inlet/outlet of a wetted system
to a wetted system sanitizing device of the present invention.
Brief Description of the Drawings
[0037] The present invention will now be described with reference to drawings, wherein:
Figure 1 shows a diagrammatic view of a house with a plumbing system that is connected
to the wetted system sanitization device of the present invention; and
Figure 2 shows a diagrammatic view of an alternative embodiment of the present invention.
Detailed Description of the Preferred Embodiments of the Present Invention
[0038] It is envisioned that the method of the present invention can be utilized to sanitize
a range of systems comprising conduits/pipes that carry water between fixtures/tools.
Such systems are referred to herein as wetted systems because, even when not in use,
they tend to contain water. It is this water that provides an environment in which
certain bacteria can flourish overtime if the water is left to sit.
[0039] In order to describe the method of the present invention in more detail, reference
will be made to Figure 1. The wetted system shown in Figure 1 is a house 1 with a
plumbing system 2, to which is connected various fixtures (e.g. water storage tank
3, water heater 4, taps 7).
[0040] As noted above, when the plumbing system of a house is left dormant for an extended
period of time - for example after initial testing of the system in a newly built
house or when a previously inhabited house is left uninhabited ― the sitting water
left in the pipes and fixtures of the house's plumbing system can harbour a range
of bacteria and other waterborne pathogens.
[0041] It is envisioned that, if left unchecked, bacteria can proliferate to levels that
can be harmful to humans when they eventually inhabit the property and start using
the house's various water based utilities (e.g. by drinking water from the taps).
[0042] In order to address these potential health risks, the present invention provides
a method of sanitizing wetted systems, such as building plumbing systems, by inducing
the movement of gases (such as air, although other forms of gas may be employed) within
the pipes and fixtures of the wetted system.
[0043] By inducing the movement of gases within the pipes and fixtures, any water and bacteria
resident therein can be extracted from the wetted system, thereby effectively sanitizing
the system.
[0044] In order to induce the movement of gases within the system a wetted system sanitization
device 5 is connected in fluid communication with the wetted system (i.e. plumbing
system 2).
[0045] Although this connection may be achieved by attaching the device 5 to an existing
inlet/outlet of the system - such as a sample/drain valve or a tap for example - it
is considered preferable that an adaptor 6 is fitted to the wetted system 2 to ensure
the creation of an efficient gas-tight seal between the wetted system sanitization
device 5 and the wetted system 2.
[0046] It is also envisioned that a section of pipe may be removed from the wetted system
to enable the wetted system sanitization device 5 of the present invention to be operatively
connected thereto.
[0047] Once the device 5 and the wetted system 2 are connected, the device 5 can be operated
to induce the movement of gases within the pipes and fixtures 3, 4.
[0048] In an arrangement shown in Figure 1, the pumping means may be operated so as to cycle
between blowing and sucking actions so as to create a tidal flow of gas movement within
the system that is akin to that of the human lungs. It is envisioned that employing
the approach allows gases to enter and leave the wetted system via a single entry
point (e.g. adapter 6).
[0049] In an alternative arrangement, such as that shown in Figure 2, the wetted system
sanitization device 5 may be operated to create a one way flow of gas through the
wetted system 2.
[0050] In the preferred example shown in Figure 2, the wetted system sanitization device
5 is configured to capture air from the local environment via an intake 9, heat the
air using heating means 10 and then blow the heated air into the wetted system 2 via
adaptors 6.
[0051] The heated air is pumped through the various conduits and pipes of the system until
it escapes for example, and as shown in Figure 2, via taps 7 or outlet 12. It is envisaged,
therefore, that when the movement of gas within the system is of a one-way nature
the gas flow may be enhanced by either opening the inlets/outlets of the wetted system
(e.g. taps, radiator valves).
[0052] Alternatively, or additionally, at least one additional outlet may be installed on
the wetted system to provide an exit for gases blown from the system.
[0053] Also, in those embodiments of the present invention where gas is sucked through the
wetted system, at least one additional inlet may be installed on the wetted system
to provide an inlet for gases sucked into the system.
[0054] It is envisioned that both the tidal flow approach and the one-way flow approach
can be delivered using a pumping means with suitable control means. However, it is
envisaged that other gas movement actuation means may be employed to induce movement
within a wetted system, such as the plumbing system shown in Figure 1.
[0055] In one alternative preferred actuation means, a source of compressed gas may be used
to generate a flow of gas within the pipes and fixtures of the wetted system. By replacing
the pumping means with a gas canister, this arrangement may provide for a more compact
and convenient design of wetted system sanitization device.
[0056] The use of gas canisters as actuation means is considered particularly suitable for
one-systems such as that shown in Figure 2.
[0057] Further preferably, and as shown in Figure 2, sensors 11 may be provided at the points
in the system where the gas escapes (e.g. taps 7). These sensors 11 can be configured
to measure various characteristics of the escaping air, such as temperature, humidity
and flow rate.
[0058] Using this information, which can be transmitted back to the wetted system sanitization
device 5 using wired or wireless communication means, the control system of the device
5 can adjust its operational levels appropriately. For example, when the flow rate
of gas escaping the system 2 is lower than a desired level, the device can increase
the pressure under which gas is pumped into the system.
[0059] In another example, a high humidity reading may trigger the heating means of the
device to increase the temperature of the gas being pumped into the system. Although
not shown in the tidal flow system of Figure 1, it is envisaged that sensors may also
be employed here. Although in these types of system it may be more beneficial to locate
the sensors within the wetted system sanitization device 5.
1. A method of sanitizing a wetted system by inducing the movement of a gas through pipes
and fixtures of said system to dry out the internal surfaces and structures of the
system, and
wherein the gas movement is achieved by blowing the gas into and through the pipes
and fixtures of said system and/or sucking the gas through and out of the pipes and
fixtures of said system.
2. The method of claim 1, wherein the gas is selected from a group consisting of: air,
carbon dioxide, and other inert gases.
3. The method of claim 1 or 2, wherein the gas movement comprises a one-directional flow
of gas through the system.
4. The method of claim 1 or 2, wherein the gas movement comprises a tidal flow of gas
into and out of the system.
5. The method of any one of claims 1 to 4, wherein the gas is heated and/or dehumidified
before entering the system.
6. The method of any one of claims 1 to 5, wherein the gas is filtered prior to entering
the system and/or upon leaving the system.
7. The method of any one of the preceding claims, wherein the flow rate and/or humidity
of the gas leaving the system is monitored; and wherein preferably:
a) the humidity level is used to adjust the extent to which the gas is dehumidified
and/or heated before entering the system; and/or
b) the gas flow rate and/or humidity level is used to adjust the extent to which the
gas is blown and/or sucked through the system.
8. The method of any one of the preceding claims, further comprising the step of installing
at least one port in the system to facilitate the blowing and/or sucking of the gas
through the system.
9. The method of any one of the preceding claims, further comprising the step of adding
a biocide to the gas prior to it entering the system.
10. The method of any one of the preceding claims, wherein a compressed gas source is
used to blow gas through the system.
11. The method of any one of the preceding claims, wherein the wetted system is a building
plumbing system.
12. A wetted system sanitization device for use in accordance with the method of any of
the preceding claims, said device comprising:
attachment means configured to form a gas tight connection with a wetted system;
actuation means configured to move gas through the wetted system via said attachment
means.
13. The device of claim 12, wherein the actuation means comprises either a pump or a compressed
gas source.
14. The device of claim 12 or 13, wherein the device further comprises:
a) a heater to heat the gas moved through the wetted system;
b) a dehumidifier to control the humidity of the gas moving through the wetted system;
c) filters;
d) pathogen containment means to safely house pathogenic materials recovered from
the wetted system; and/or
e) control means that monitors the rate of gas flow leaving the wetted system and
adjusts the operation of the actuation means accordingly.
15. The device of any one of claims 12-14, wherein the attachment means are configured
to form a closed circuit between the wetted system and the device.