[0001] The invention relates to a module for discharging flue gases for a stove.
[0002] Stoves are generally known heating means for homes. Where in the past a stove was
usually provided as multi-burner, optionally optimized for burning wood and/or coal,
there is a trend in recent years to provide more pellet stoves or gas stoves which
are specifically provided to burn respectively pellets or gas. The advantage of pellets
or gas as fuel is that the supply of the fuel can be controlled mechanically in automatic
manner so that the energy output of the stove can be controlled thereby.
[0003] A stove is defined as a heating device wherein the primary object is direct heating
of the immediate area around the stove. A stove is typically distinguished from other
heating means in that it is a secondary object of a stove to achieve an aesthetically
appealing combustion in the stove. The combustion chamber is for this purpose formed
as a casing in which the combustion can take place, and a part of the casing is formed
by a transparent material, for instance glass. The transparent material here has dimensions
which are chosen to simultaneously allow several people in the area surrounding the
stove to see the flames created during the combustion process in the combustion chamber.
[0004] In order to optimize the combustion in the stove a good ratio of fuel and combustion
air is essential. Different techniques for controlling the combustion air flow have
been known for a long time. The heat of the flue gases creates a so-called draught
in the chimney, which draws combustion air through the combustion chamber. This airflow
can then be influenced or controlled by placing a valve at the inlet of the combustion
chamber and/or at the outlet of the combustion chamber for the purpose of throttling
the duct through which the combustion air flows. The natural draught of the chimney
can be enhanced by placing a fan. This fan is typically placed upstream of the combustion
chamber in the airflow duct in order to push the air through the combustion chamber
in a controlled manner.
[0005] It is an object of the invention to improve the operation of a stove with active
combustion air flow controllers and to increase the safety of such a stove.
[0006] The invention provides for this purpose a module for discharging flue gases, comprising
a frame with a flue gas duct extending through the frame, wherein the flue gas duct
is delimited by a flue gas duct wall and wherein a throttle valve is provided in the
flue gas duct, wherein a control element for opening and closing the throttle valve
further extends through the flue gas duct wall between the throttle valve and an actuator,
wherein the frame further comprises a mounting wall for mounting of the actuator,
and wherein the mounting wall is provided at a distance from the flue gas duct wall
in order to prevent direct heat transfer from the flue gas duct wall to the actuator.
[0007] The module according to the invention is optimized for discharging flue gases, and
is thereby typically placed on the outlet side of the combustion chamber of the stove.
The placing of a flue gas extractor in a discharge for flue gases is made difficult
in practice by the temperature of the flue gases. The temperature of the flue gases
will typically heat the discharge for flue gases, and thereby also heat the flue gas
extractor, so that this latter must be able to operate properly at high temperatures.
However, because in the invention a mounting wall is provided on which the actuator
is mounted, and wherein the mounting wall is provided at a distance from the flue
gas duct wall, it is possible to prevent the heat of the flue gases which flow in
the flue gas duct from being transferred directly to the actuator. Due to this construction,
the actuator can be screened from the heat of the flue gases and the module can function
reliably.
[0008] The process of combustion in the combustion chamber is largely dependent on the ratio
of fuel and air in the combustion chamber. The module according to the invention can
determine the quantity of air which flows through the combustion chamber, whereby
the module ca control the combustion via the actuator and throttle valve. An efficient
operation of the stove can be achieved hereby.
[0009] The invention further has an unexpectedly positive effect. Because the module is
optimized for placing in the discharge for flue gases, the module will draw air through
the combustion chamber. The result hereof is that the combustion chamber of the stove
is subjected to underpressure. Because a combustion chamber and the elements mounted
thereon, such as a discharge for flue gases and feed for combustion air, can never
be manufactured so as to be 100% airtight, it is an advantage to have an underpressure
in the stove because the underpressure ensures that possible soot or CO or other harmful
byproducts of a combustion will not leak out of the stove, or hardly so. This in contrast
to stoves which actively blow combustion air to the combustion chamber, which is thereby
at overpressure, and which do tend to allow soot, CO
2 and other harmful combustion products to leak to the area surrounding the stove.
This effect of leakage from the combustion chamber is enhanced in practice by modern
airtight insulated houses wherein the air is refreshed by means of a balanced ventilation
system and wherein in accordance with recent building regulations the space in the
house may be subject to slight underpressure.
[0010] The module is preferably formed such that the flue gas duct wall sub-divides the
frame into a first part which is provided to enclose the flue gases and a second part,
wherein the frame has ventilation openings in the second part. The actuator is placed
in the second part, which has ventilation openings, and on a mounting wall which is
provided at a distance from the flue gas duct wall. Heat which still finds its way
to the mounting wall will hereby not be given the opportunity to heat the mounting
wall appreciably, because the second part of the frame is ventilated by means of the
ventilation openings.
[0011] The throttle valve is preferably formed by mounting a plate movably relative to a
fixedly positioned opening in the flue gas duct, such that the plate is movable between
a first position in which the plate substantially closes the opening and a second
position in which the plate impedes an airflow through the opening to minimal extent.
Tests have shown that constructing a throttle valve in such a manner is reliable and
achieves a correct operation at low and at high temperatures. Controlling of the throttling
and the opening and closing of the opening by means of the movable plate can further
be mechanically controlled and realized in simple manner.
[0012] The plate is preferably fixedly connected to a control element which is movable by
the actuator via an intermediate element so as to move the plate between the first
position and the second position. The control element is here preferably further positioned
eccentrically relative to the rotation axis, and the intermediate element is formed
as a connecting rod. The fixedly positioned opening preferably extends over only a
part of the partition. On one side of the partition the flue gas duct is here preferably
provided with a section smaller than the section of the partition. The partition thereby
forms at least partially a segment of the flue gas duct wall. This allows the plate
to be placed on the partition with a shaft extending through the partition from a
position inside the flue gas duct to a position outside the flue gas duct. The plate
is then positioned on the side of the partition where the flue gas duct has a greater
section, while the control element extends to, and the eccentric part of the control
element in particular is situated at a position outside, the flue gas duct. Such a
construction can be realized in simple manner and produces a reliable operation. It
is further easy to control the movable plate in this way by means of the actuator.
By further providing a connecting rod the distance between the actuator and the plate
with the control element can be increased further, so that heat transfer from plate
to actuator is further reduced.
[0013] An insulating panel is preferably provided between the flue gas duct wall and the
mounting wall. The insulating panel further reduces the heat transfer between the
flue gas duct wall and the mounting plate. The insulating panel allows the distance
between the mounting plate and the flue gas duct wall to be small, while still achieving
a good thermal separation.
[0014] The mounting wall and the flue gas duct wall preferably have an opening which in
mounted state is aligned such that a lambda probe can be placed through the opening
and can be mounted against the mounting wall. The lambda probe serves to measure the
quantity of oxygen in the flue gases, and will therefore need to extend at least partially
into the flue gas duct. By mounting the lambda probe against the mounting plate, which
is at least partially thermally separated from the flue gas duct wall, the temperature
of the lambda probe can be optimized.
[0015] The actuator is preferably formed as a servomotor, wherein a lever arm is provided
on the rotation shaft of the servomotor, which lever arm has an eccentric connection
for connecting to the control element. The control element can here be connected via
the connecting rod to the eccentric connection of the servomotor. It is possible to
achieve a precise actuation of the plate via the servomotor, so that the throttle
valve can be precisely controlled.
[0016] The module is preferably operatively connected to a stove with a combustion chamber
and smoke discharge, and the module is preferably mounted at a distance of at least
1 metre, preferably at least 2 metres, more preferably at least 3 metres and at a
distance of a maximum of 10 metres, preferably a maximum of 8 metres, more preferably
a maximum of 6 metres from the combustion chamber of the stove. Tests have shown that
placing the module at such a distance from the combustion chamber is optimal on the
one hand for controlling the airflow and on the other hand for controlling the temperatures
in the module.
[0017] The invention further relates to a stove with a combustion chamber and active combustion
air flow controller which is operatively connected to the stove for the purpose of
controlling an airflow through the combustion chamber, wherein the active combustion
air flow controller is formed by a module according to the above described invention.
[0018] The invention will now be further described with reference to an exemplary embodiment
shown in the drawing.
[0019] In the drawing:
figure 1 shows a stove with a construction according to a preferred embodiment of
the invention;
figure 2 shows a first section of a module according to a preferred embodiment of
the invention; and
figure 3 shows a second section of a module according to a further preferred embodiment
of the invention.
[0020] The same or similar elements are designated in the drawing with the same reference
numerals.
[0021] Figure 1 shows a stove 1 which is connected according to a preferred embodiment of
the invention. A stove has already been defined above as a heating device wherein
the primary object is direct heating of the immediate area around the stove, and wherein
the secondary object is to achieve an aesthetically appealing combustion in the stove.
A stove can further be defined as a fireplace, this being an open fireplace or closed
fireplace, with an active combustion air flow controller. When the combustion air
is actively controlled in a fireplace, as in the context of the present invention,
the terms fireplace and stove can therefore be used synonymously with each other.
Tertiary airflows can here further be controlled at the stove, which do not run through
the combustion chamber but do run around the combustion chamber in order to thus extract
heat from the combustion chamber, which tertiary air can then be guided via a network
of ducts to other spaces so that spaces which are not deemed to be the immediate surrounding
area can also be heated by the stove.
[0022] Stove 1 comprises a combustion chamber 2 which is formed as a casing for the fire
when fuel is combusted, and wherein at least a part of the casing is formed by a transparent
material 3, for instance glass. Glass 3 has a surface area which is preferably greater
than 0.04 m
2, more preferably at least 0.1 m
2 and most preferably greater than 0.2 m
2. The glass can extend in one or more sides of casing 2 so that traditional built-in
stoves as well as corner stoves and/or see-through stoves can be formed. During combustion
of fuel the fire 4 present inside the casing of combustion chamber 2 is visible to
several users at the same time through transparent material 3.
[0023] Stove 1 is provided with an active combustion air flow controller. Stove 1 is provided
for this purpose with a feed for combustion air 5 and a discharge for flue gases 6.
The combustion air feed 5 and flue gas discharge 6 can be formed coaxially (not shown)
or, as illustrated in figure 1, be formed and placed separately of each other. The
combustion air feed 5 preferably extends into a space other than the space in which
combustion chamber 2 is situated. An airflow, illustrated with arrow 7, can be supplied
via combustion air feed 5 to the combustion chamber. This air, which serves for the
combustion, is also referred to as combustion air 7.
[0024] The flue gas discharge 6 preferably extends to a chimney. Flue gases can be discharged
via flue gas discharge 6, which is illustrated in figure 1 with arrow 8. Flue gases
8 are guided via flue gas discharge 6 into the chimney, where they can flow out via
the chimney, which is illustrated in figure 1 with arrow 9.
[0025] Stove 1 is preferably provided with an automatic fuel supply for supplying fuel to
the combustion chamber, which is illustrated in figure 1 with arrow 10. In figure
1 a reservoir 11 in which fuel, for instance pellets, is stored is provided at combustion
chamber 2, wherein a duct extends from reservoir 11 to the combustion chamber. Providing
a controller (not shown) in the duct allows fuel to be carried from reservoir 11 to
combustion chamber 2 in a controlled manner. It will be apparent that this is only
one example of an embodiment for supplying fuel. A gas conduit to combustion chamber
2 can alternatively be placed, wherein a valve is provided in the gas conduit in order
to allow gas to enter combustion chamber 2 in a controlled manner. These are only
two examples of automatic fuel supply systems, and the skilled person will be easily
able to apply alternatives and/or equivalent automatic fuel supply systems in the
present invention.
[0026] Stove 1 further comprises a module 12 for actively controlling the airflow which
flows through combustion chamber 2. In the figure module 12 is placed in the flue
gas discharge 6. Module 12 can alternatively be placed in combustion air feed 5. Module
12 comprises an air pump for actively controlling an airflow, which air pump is formed
by a combination of a fan 13 and a throttle valve 14 in figure 1. The skilled person
will here also understand that alternative active air pumps can be applied as replacement
for the combination of fan 13 and throttle valve 14. Tests have shown that a combination
of fan 13 and throttle valve 14 produces good and reliable results and is therefore
a preferred air pump. Module 12 preferably further comprises a lambda probe 15 for
measuring the oxygen content in the flue gases.
[0027] The different components of stove 1, such as the combustion chamber 2 with automatic
fuel supply 10 and the module 12 with fan 13, throttle valve 14 and lambda probe 15,
are operatively connected to a controller 17. The operative connection is illustrated
in figure 1 with reference numeral 16. The operative connection can in practice be
formed via cabling, wirelessly, or via a combination thereof.
[0028] Controller 17 comprises a processor with one or more inputs for reading sensors and/or
states of components of stove 1. It will be apparent here that sensors can be formed
by pressure sensors, temperature sensors, the lambda sensor 15, position sensors,
for instance for measuring a position of a door or valve on the combustion chamber,
the reservoir 11 or the module 12. The skilled person will understand that different
sensors for measuring different states or properties can be placed in the stove, and
that the list provided above is not limitative. States of components can be understood
to mean the rotation speed of fan 13, the position of throttle valve 14, the filling
level of reservoir 11, the supply speed 10 of the fuel. The skilled person will understand
that different states and different properties of stove 1 can be read and that the
summary provided above is not limitative. The processor is provided for processing
the inputs and for controlling outputs.
[0029] Controller 17 preferably further comprises a plurality of outputs which are controlled
by the processor for transmitting signals or instructions to different components
of stove 1. It is preferably possible via the output to control fuel supply 10, to
control fan 13 and to control throttle valve 14. Controller 17 is shown as a separate
module in figure 1. The skilled person will however understand that controller 17
can also be integrated into one of the other components of the stove, for instance
into combustion chamber 2 or into module 12. Controller 17 can also be distributed
over different components, wherein different functions, inputs, outputs and/or computations
can be executed at different locations in stove 1.
[0030] Controller 17 further comprises a user interface 18. A user interface 18 is shown
as a remote control in figure 1. The user interface can also be formed as an application
on an electronic end user device, for instance an application on a smart phone, so
that controller 17 can be controlled by the user via the user interface 18. Instructions
can be sent via user interface 18 to controller 17, which then further controls stove
1 on the basis of the instructions, taking into consideration the inputs, so as to
guarantee an optimal, safe and correct operation of stove 1.
[0031] Figure 2 shows a module 12 for discharging flue gases for a stove according to a
preferred embodiment of the invention. Figure 2 shows here a module 12 wherein flue
gases flow from the stove into module 12 on a left-hand side of the figure, which
is designated with reference numeral 8. On the right-hand side of module 12 the flue
gases leave the module in the direction of the chimney, which is designated with reference
numeral 9. The inlet and the outlet of module 12, between which flue gas duct 6 extends,
are thereby shown. Further situated between this inlet and this outlet, in flue gas
duct 6, are fan 13 and throttle valve 14. The flue gas duct in module 12 is delimited
by a flue gas duct wall 19. Because the flue gases come into direct contact with flue
gas duct wall 19, the temperature of flue gas duct wall 19 will be greatly affected
by the temperature of the flue gases. The flue gas duct wall will therefore also become
warm or hot in practice.
[0032] An opening 20 is provided in the flue gas duct wall so that a lambda probe 15 can
extend through flue gas duct wall 19 and into the flue gas duct. A lambda probe 15
typically has a base body and a sensor part extending from this base body. Opening
20 allows the base body to be mounted outside flue gas duct 6, while the sensor extends
through the flue gas duct wall 19 and into the flue gas duct 6. The base body of lambda
probe 15 can be mounted on mounting wall 23, which will be discussed in more detail
hereinbelow. This mounting of lambda probe 15 on mounting wall 23 is designated in
the figure with reference numeral 36.
[0033] Throttle valve 14 is preferably formed by means of a movable plate 28 which is situated
in flue gas duct 6 and which is mounted movably, preferably rotatably, via a control
element 21, 32, which is shown in the embodiment of figure 2 as a rotation shaft 21
with an eccentric part 32. In the figure the eccentric part 32 of the control element
extends to a position outside flue gas duct 6. Rotation shaft 21 of the control element
extends for this purpose from eccentric part 32 all the way up to movable plate 28
through the flue gas duct wall 19. This eccentric part 32 is preferably connected
via a connecting rod 33 to a lever arm 37 of an actuator 22. A system of rods which
allows operation of movable plate 28 with an actuator 22 is hereby obtained. The skilled
person will understand that the lengths of lever arm 37, connecting rod 33 and eccentric
part 32 of control element 21, 32 can be designed so as to achieve an optimal transmission
of force and of movement from actuator 22 to movable plate 28. The system of rods
has the advantage that heat is given minimal opportunity to transfer through the system
of rods to actuator 22, since the distance over which the heat must transfer is increased
considerably by the system of rods. Movable plate 28 is situated in flue gas duct
6 and, with this, is in direct contact with the flue gases such that the temperature
of movable plate 28 is affected considerably by the temperature of the flue gases.
The movable plate will become hot in practice. The system of rods, consisting of the
control element 21 with the eccentric part 32, the connecting rod 33 and the lever
arm 37 on actuator 22, prevents to maximum extent that heat flows from movable plate
28 to actuator 22. A highly reliable operation of movable plate 28 can further be
achieved.
[0034] Two parts can be distinguished from each other in module 12. A first part is the
part through which flue gases flow, is designated with 6 in the figure, and is typically
the part which is enclosed by flue gas duct wall 19. A second part 25 is adjacent
to the first part and is separated therefrom by at least a part of flue gas duct wall
19. In figure 2 this second part is formed substantially by the lower half of module
12, with the exception of the part on the far right in the figure. The second part
25 is not provided for allowing flow of flue gases. The sensors, control elements
and other components which provide for a good operation of module 12 are typically
placed in this second part. The second part 25 of module 12 is preferably encased
so as to protect the elements in second part 25. The casing is preferably provided
with ventilation openings 30 or perforations to allow a good ventilation of second
part 25. Heat can be discharged in simple manner via ventilation openings 26.
[0035] A mounting wall 23 is provided in second part 25 of module 12. Mounting wall 23 is
provided at a distance 24 from flue gas duct wall 19. An insulating panel 34 which
reduces heat transfer from flue gas duct wall 19 to mounting wall 23 preferably extends
between mounting wall 23 and flue gas duct wall 19. The distance 24 can be minimized
when an insulating panel 34 with good insulating properties is provided, without reducing
the reduction in heat transfer herein. In an embodiment in which no insulating panel
34 is provided, or an insulating panel 34 with fewer insulating properties is provided,
the distance 24 between mounting wall 23 and flue gas duct wall 19 can be increased
so as to limit heat transfer. The skilled person will understand that the distance
24 in combination with an optional insulating panel 34, in further combination with
the ventilation openings 26 which are provided in second part 25 of module 12, can
be adapted to each other in order to limit the maximum temperature of mounting wall
23 in a normal operating mode of module 12.
[0036] Mounting wall 23 is configured for mounting of one or more operating elements of
module 12. In the embodiment of figure 2 lambda probe 15 is connected to mounting
wall 23, which is designated with reference numeral 36. Actuator 22 is also connected
to mounting wall 23. In the embodiment of figure 2 spacers 35 are provided between
mounting wall 23 and actuator 22, which spacers 35 further reduce direct heat transfer
between mounting wall 23 and actuator 22. In the configuration as seen in figure 2
the mounting of the actuator by means of spacers 35 allows lever arm 37 to extend
toward flue gas duct wall 19 such that it extends closer to the eccentric part 32
of control element 21, and can thus be mounted together with connecting rod 33 in
an optimal manner.
[0037] In the context of this invention the skilled person will understand that reduction
of heat transfer is understood to mean that the resistance to heat transfer is directly
or indirectly increased. Principles for increasing resistance to heat transfer and
measuring and ascertaining thereof are generally known and are therefore not elucidated
in further detail.
[0038] Throttle valve 14 with movable plate 28 divides flue gas duct 6 into two sections.
A first section is shown in figure 2 in an upper half of module 12, and lies upstream
of throttle valve 14. A second section is shown in figure 2 on the right-hand side
of the figure, below this upper half, and lies downstream of throttle valve 14. These
two sections can be deemed as separated by a partition 29 which is visible in figure
3. The skilled person will understand from a combination of figure 3 and figure 2
that partition 29 at least partially forms the flue gas duct wall 19. In the embodiment
of figure 2 partition 29 extends in the flow direction of flue gases 8, and these
flue gases 8 must flow around a bend in order to flow to the second section. In an
alternative configuration the partition 29 can be placed transversely of the flow
direction of flue gases 8, so that the flue gases can flow straight through throttle
valve 14 when throttle valve 14 is open.
[0039] Partition 29 has an opening 27 which is smaller than partition 29. Movable plate
28 is formed such that in a first position, this being the position as shown in figures
2 and 3, it almost wholly covers opening 27. Air is hereby prevented to maximum extent
from flowing through opening 27. Throttle valve 14 can then be deemed as closed. Movable
plate 28 can be moved to a second position (not shown), in which movable plate 28
extends adjacently of opening 27 and thereby does not cover the opening appreciably.
Air can hereby flow unimpeded through opening 27. A first stop 30, which establishes
a first end position of movable plate 28, more specifically the first position, is
preferably provided. This stop 30 will stop the movement of movable plate 28 toward
the first position when plate 28 reaches an optimal first position. The movement of
movable plate 28 is designated in the figure with arrow 44. A second stop 31 is preferably
further provided, which stops the movable plate in the second position. When movable
plate 28 moves toward the second position, it will hit second stop 31 when an optimal
second position is reached. Physical boundaries for movement 44 of movable plate 28
are established by providing first stop 30 and second stop 31. The skilled person
will understand that the embodiment described here and shown in figures 2 and 3 is
only a preferred embodiment of a throttle valve 14. Throttle valves having a similar
functionality can also be constructed on the basis of other principles, such as with
a tilting plate which rotates relative to the partition instead of sliding relative
to the partition, as described above.
[0040] Figure 3 shows the system of rods for operating movable plate 28. Movable plate 28
is connected to an eccentric part 32 via the control element extending through flue
gas duct wall 19 via a rotation shaft 21. The eccentric part 32 and the rotation shaft
21 can be formed integrally or can be made from a plurality of pieces and be fixedly
connected to each other. The position of eccentric part 32 and movable plate 20 is
fixed via the rotation shaft. Rotation of eccentric part 32 of the control element
will therefore result in a corresponding rotation of movable plate 28 around rotation
shaft 21. Actuator 22 has a lever arm 37 which is provided on the shaft of actuator
22. This lever arm 37 is connected via a connecting rod 33 to the eccentric part 32
of the control element. Rotation of the actuator, as illustrated with arrow 38, will
therefore bring about a rotation of eccentric part 32, whereby movable plate 28 is
also moved. This construction allows actuator 22 to be positioned at a distance from
movable plate 28, such that heat transfer from movable plate 28 to actuator 22 is
minimal. The skilled person will understand that this is only a preferred embodiment
for driving of movable plate 28, and that alternative embodiments can be envisaged.
[0041] Figure 3 further shows how lambda probe 15 is connected via mounting elements 36
to mounting wall 23. The mounting wall of the embodiment of figure 2 is preferably
provided with a substantially flat side and a side with mounting elements. The substantially
flat side can be directed toward the flue gas duct wall and can be placed at a distance
therefrom, so that no or no appreciable heat or cold bridges are created between the
mounting wall and the flue gas duct wall. The connecting elements can then be used
to connect elements such as lambda probe 15 and/or actuator 22 to mounting wall 23.
[0042] Figure 2 further shows a fan 13. In the embodiment of figure 2 fan 13 is placed in
the second section of flue gas duct 6. Fan 13 has blades 40 which extend in flue gas
duct 6 in order to drive the flue gases. In the example of figure 2 blades 40 are
radial blades for drawing the air centrally into the fan and accelerating it radially
relative to the fan in the direction of arrow 9. Blades 40 are driven by a motor 39
for the fan. This motor is placed in the second part 25 of module 12 so that the motor
can be cooled by air which can flow through the ventilation openings 26 in the second
part. The airflow can be driven by fan 13. Fan 13 in combination with throttle valve
14 allows the speed and/or the flow rate of the airflow to be controlled.
[0043] In the embodiment of figure 2 module 12 further comprises a pressure gauge 41. In
the embodiment of figure 2 pressure gauge 41 is connected to an opening 42 which is
situated upstream of throttle valve 14 in flue gas duct 6. In the embodiment of figure
2 pressure gauge 41 is further connected to an opening 43 situated downstream of throttle
valve 14. This allows pressure gauge 41 to measure two pressures, upstream and downstream
of throttle valve 14. The control of module 12 and, in line therewith, the control
of stove 1, can be optimized on the basis of these pressures or on the basis of a
pressure difference. Instead of or in addition to pressure gauge 41 it is possible
to add other sensors in the module, for instance temperature sensors or soot sensors,
in order to gauge a state of module 12 and/or of flue gases 6 and/or of a component
of module 12. Communication modules or connections for cabling can further be provided
in the second part 25 of module 12 in order to allow the different components of module
12, particularly actuator 22, lambda probe 15 and optional other gauges such as pressure
gauge 41, to communicate with components of stove 1 which are situated at a distance
from module 12.
[0044] Module 12 is preferably further provided with a self-closing valve, which is designated
in figures 1 and 2 with reference numeral 44. By providing a mechanical one-way valve
in the flue gas discharge an unsafe situation, for instance when two stoves are provided
in a residential unit and are connected to one chimney, and when one of the stoves
loses power, is avoided. This is because combustion air from a different stove can
never flow back via the flue gas discharge into the stove owing to mechanical one-way
valve 44, because the mechanical one-way valve prevents such a flow irrespective of
the state of valve 14.
[0045] The skilled person will appreciate on the basis of the above description that the
invention can be embodied in different ways and on the basis of different principles.
The invention is not limited here to the above described embodiments. The above described
embodiments and the figures are purely illustrative and serve only to increase understanding
of the invention. The invention is not therefore limited to the embodiments described
herein, but is defined in the claims.
List of reference numerals
[0046]
1: stove
2: combustion chamber
3: transparent material
4: fire
5: supply for combustion air
6: discharge for flue gases
7: airflow combustion air
8: flue gases
9: flow of flue gases to chimney
10: fuel supply
11: reservoir
12: module
13: fan
14: throttle valve
15: lambda probe
16: operative connection
17: controller
18: user interface
19: flue gas duct wall
20: opening lambda probe
21: control element/rotation shaft
22: actuator
23: mounting wall
24: distance (flue gas duct wall - mounting wall)
25: second part of module
26: ventilation opening
27: opening
28: movable plate
29: partition
30: stop first position
31: stop second position
32: eccentric part of control element
33: connecting rod
34: insulating panel
35: spacers
36: mounting of lambda probe on mounting wall
37: lever arm
38: servomotor movement
39: motor for ventilation
40: blades of fan
41: pressure gauge
42: opening for measuring pressure upstream of throttle valve
43: opening for measuring pressure downstream of throttle valve
44: self-closing valve
1. Module for discharging flue gases, comprising a frame with a flue gas duct extending
through the frame, wherein the flue gas duct is delimited by a flue gas duct wall
and wherein a throttle valve is provided in the flue gas duct, wherein a control element
for opening and closing the throttle valve further extends through the flue gas duct
wall between the throttle valve and an actuator, wherein the frame further comprises
a mounting wall for mounting of the actuator, and wherein the mounting wall is provided
at a distance from the flue gas duct wall in order to prevent direct heat transfer
from the flue gas duct wall to the actuator.
2. Module according to claim 1, wherein the flue gas duct wall sub-divides the frame
into a first part which is provided to enclose the flue gases and a second part, wherein
the frame has ventilation openings in the second part.
3. Module according to any of the foregoing claims, wherein the throttle valve is formed
by mounting a plate movably relative to a fixedly positioned opening in the flue gas
duct, such that the plate is movable between a first position in which the plate substantially
closes the opening and a second position in which the plate impedes an airflow through
the opening to minimal extent.
4. Module according to claim 3, wherein the fixedly positioned opening is formed in a
partition in the flue gas duct and wherein the plate is mounted parallel to the partition
and is rotatable around a rotation axis which is oriented perpendicularly of the partition.
5. Module according to claim 3 or 4, wherein the plate is fixedly connected to a control
element which is movable by the actuator via an intermediate element so as to move
the plate between the first position and the second position.
6. Module according to claim 4 and 5, wherein the control element is positioned eccentrically
relative to the rotation axis and wherein the intermediate element is formed as a
connecting rod.
7. Module according to any of the foregoing claims, wherein an insulating panel is provided
between the flue gas duct wall and the mounting wall.
8. Module according to any of the foregoing claims, wherein the actuator is connected
to the mounting wall via spacers.
9. Module according to any of the foregoing claims, wherein the mounting wall and the
flue gas duct wall have an opening which in mounted state is aligned such that a lambda
probe can be placed through the opening and can be mounted against the mounting wall.
10. Module according to any of the foregoing claims, wherein the actuator is formed as
a servomotor, wherein a lever arm is provided on a rotation shaft of the servomotor,
which lever arm has an eccentric connection for connecting to the control element.
11. Module according to any of the foregoing claims, operatively connected to a fireplace
comprising a combustion chamber with a flue gas discharge, and wherein the module
is mounted at a distance of at least 1 metre, preferably at least 2 metres, more preferably
at least 3 metres and at a distance of a maximum of 10 metres, preferably a maximum
of 8 metres, more preferably a maximum of 6 metres from the combustion chamber of
the fireplace.
12. Fireplace with a combustion chamber and an active combustion air flow controller which
is operatively connected to the fireplace for the purpose of controlling an airflow
through the combustion chamber, wherein the active combustion air flow controller
is formed by a module according to any of the foregoing claims.