U.S. patent application number 10/672401 was filed with the patent office on 2005-03-31 for water heater with mechanical damper.
Invention is credited to Guzorek, Steven E..
Application Number | 20050066958 10/672401 |
Document ID | / |
Family ID | 34376349 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050066958 |
Kind Code |
A1 |
Guzorek, Steven E. |
March 31, 2005 |
Water heater with mechanical damper
Abstract
A hot water heater comprises a valve control unit having a gas
inlet, a pilot burner, a main burner and a damper assembly. The
damper assembly has a pressure diaphragm, a gearing mechanism and a
movable damper. The control unit being coupled to operatively
supply gas to the pilot burner, the main burner and the damper
assembly whereby when gas is supplied to the damper assembly, the
pressure diaphragm is moved to thereby cause the gearing mechanism
to move the damper from a first position to a second position.
Inventors: |
Guzorek, Steven E.;
(Kinston, NC) |
Correspondence
Address: |
John G. Bisbikis, Esq.
McDermott, Will & Emery
Suite 4400
227 West Monroe Street
Chicago
IL
60606
US
|
Family ID: |
34376349 |
Appl. No.: |
10/672401 |
Filed: |
September 26, 2003 |
Current U.S.
Class: |
126/285R |
Current CPC
Class: |
F23N 3/047 20130101;
F24H 1/205 20130101; F23L 13/00 20130101 |
Class at
Publication: |
126/285.00R |
International
Class: |
F24H 009/20 |
Claims
1. A damper assembly for a gas hot water heater comprising: a drive
unit, the drive unit including a pressure diaphragm and a rack, an
axle having a pinion, said pinion engaging the rack; a damper, said
damper being coupled to the axle wherein said damper has a first
position and a second position; and a detector for sensing the
position of said damper.
2. The assembly of claim 1 wherein said pressure diaphragm is a
bellows.
3. The assembly of claim 1 wherein said diaphragm has a first
diaphragm position and a second diaphragm position, wherein when
said diaphragm is in said first diaphragm position, said damper is
rotated to a said first position and when said diaphragm is in a
said second diaphragm position, said damper is rotated to a said
second position
4. The assembly of claim 1 wherein said damper is mounted to said
axle at a non-central pivot point.
5. The assembly of claim 1 wherein said damper is generally
circular.
6. A hot water heater comprising: a valve control unit having a gas
inlet; a pilot burner; a main burner; and a a damper assembly
having a pressure diaphragm, a gearing mechanism and a movable
damper; said control unit being coupled to operatively supply gas
to said pilot burner, said main burner and said damper assembly;
whereby when gas is supplied to said damper assembly, said
diaphragm is moved, causing said gearing mechanism to move said
damper from a first position to a second position.
7. The hot water hear of claim 6 wherein said damper assembly also
includes a housing, said damper being mounted to said housing.
8. The hot water heater of claim 6 further comprising a control
circuit coupled to said control unit whereby said control unit will
only supply gas to said main burner when said damper is in said
second position.
9. The hot water heater of claim 6 further comprising control
circuit having a detector switch coupled to said control unit,
whereby said detector, upon the detection of the gas will cause the
control unit to stop supply of gas to said pilot burner.
10. A method of operating hot water heater having a valve control
unit, a pilot burner, a main burner and a pressure operated
mechanical damper comprising the steps of: supplying gas to said
valve control unit from a main gas supply, said valve unit
supplying gas to said pilot burner, said valve unit supplying gas
to said pressure operated damper causing said damper to move from a
first position to a second position.
Description
TECHNICAL FIELD
[0001] The present subject matter relates generally to systems for
venting exhaust fumes generated by gas hot water heaters. More
particularly, the present subject matter relates to a venting
system for a gas hot water heater having a mechanical damper.
BACKGROUND
[0002] Hot water heaters are commonly used to provide hot water for
use in homes, offices and other residential and commercial
buildings. Hot water heaters can be electric or gas powered. Gas
powered hot water heaters generally have a main gas burner that is
located underneath a water tank. When the burner is operating, it
burns a gas, such as natural gas or LP gas, to generate heat which
heats the water in the tank. The burner creates combustion fumes as
byproducts of burning the gas. The fumes must be vented to outdoor
air and usually are carried away or exhausted through a main
exhaust pipe which generally passes through the center of the water
tank to the top of the tank. At the top of the tank, the main
exhaust pipe cooperates with another exhaust pipe that allows the
fumes to flow to outside air.
[0003] Controlled flow of the gas and exhaust fumes is important to
safety as well as the efficiency of the gas water heater. When the
burner is operating, the exhaust pipe must be maintained open in
order to allow the exhaust fumes to pass through. When the burner
is not operating, however, it can be desirable to close the exhaust
pipe to prevent heat from leaving the tank through the exhaust
pipe.
[0004] It is therefore desirable to provide a low cost, effective
and reliable damper for the exhaust pipe of hot water heaters.
SUMMARY
[0005] The present concepts provide a method and system for
operatively damping the exhaust pipe of a hot water heater.
[0006] It is an object of the present subject matter to improve the
efficiency of gas hot water heaters by reducing heat loss when the
burner is off.
[0007] It is an object of the present subject matter to provide a
reliable damper system that opens automatically upon operation of
the main burner.
[0008] It is an object of the present subject matter to provide a
damper system that closes automatically when the main burner is not
operating.
[0009] The following drawings and description set forth additional
advantages and benefits of the subject matter. More advantages and
benefits will be obvious from the description and may be learned by
practice of the subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present subject matter may be better understood when
read in connection with the accompanying drawings, of which:
[0011] FIG. 1 shows a gas water heater with a mechanical damper
assembly.
[0012] FIG. 2A shows a perspective view of a mechanical damper
assembly.
[0013] FIG. 2B shows a front view of a mechanical damper
assembly.
[0014] FIG. 2C shows a top view of a mechanical damper
assembly.
[0015] FIG. 3 shows a pressure operated drive unit and a gearing
mechanism of the mechanical damper assembly.
[0016] FIG. 4 is a schematic diagram of one example of a hot water
heater burner, valve control unit and damper assembly.
[0017] FIG. 5 is a schematic diagram of a second example of a hot
water heater burner, valve control unit and damper assembly.
[0018] FIG. 6 is a schematic diagram of a third example of a hot
water heater burner, valve control unit and damper assembly.
[0019] FIG. 7 is a schematic diagram of a fourth example of a hot
water heater burner, valve control unit and damper assembly.
DETAILED DESCRIPTION
[0020] FIG. 1 shows a hot water heater 10. The hot water heater 10
has a tank 12 to hold the water, a pipe 14 to supply the tank with
cold water to be heated, a pipe 16 to let hot water out of the tank
and a tube or pipe 18 with a pressure relief valve 20 for releasing
water if too much pressure is generated inside the tank 12. The
heater 10 also has a burner 22 located under the water tank 12 for
heating water inside of the tank 12. An exhaust vent or pipe 24 is
also provided for allowing combustion fumes from the burner 22 to
be exhausted away from the area around the heater 10, preferably to
an outdoor area. As shown, the exhaust vent 24 passes through the
center of the tank 12. The burner 22 is coupled to a valve control
unit 26 via a gas tube or pipe 28. The valve control unit 26 is
also coupled to a mechanical damper assembly 30 via another gas
tube or pipe 32. The valve control unit 26, which will be described
in more detail below, contains one or more valves which selectively
control flow of gas to and operation of the burner 22 and damper
assembly 30.
[0021] As shown in more detail in FIGS. 2A, 2B, 2C and 3, the
damper assembly 30 has a drive unit 34, an axle 36, a damper 38 and
a housing 40. The axle 36 may be a single axle or a series of axles
coupled together by gearing mechanisms as shown. The drive unit 34
is pressure-operated. As shown, the drive unit 34 has a pressure
diaphragm 42, such as a bellows mounted within a diaphragm housing
43. The housing 43 can be any shape so long as it creates a
pressure cavity into which gas can be supplied to create a pressure
on the diaphragm 42. The diaphragm housing 43 is connected to a
mounting plate 45 which can be attached to the heater 10. The
diaphragm 42 can be biased to a first position in normal
atmospheric pressure, but can move to a second position when a
certain pressure level is applied to one side of the diaphragm 42.
As shown in FIG. 1, the drive unit 34 can be installed on a heater
10 such that the diaphragm 42 is in a generally horizontal plane. A
rod 44 having a rack 46, can be connected to the diaphragm 42. The
rack 46 engages a pinion 48 on or connected to an axle 36. The axle
36 is thus rotated upon movement of the rack 46. The damper 38 is
also coupled to the axle 36, directly or through a series of axles
and gears, and thus is also rotated upon movement of the rack 46.
Movement of the diaphragm 42 from the first position to the second
position, and vice-versa, causes translational movement of the rack
46, which causes rotation of the axle 36 and damper 38. For
example, movement of the diaphragm 42 from the first position to
the second position may cause clockwise rotation of the axle 36 and
damper 38 to an open position (as will be described below) and
movement of the diaphragm 42 from the second position back to the
first position may cause counter-clockwise rotation of the axle 36
and damper 38 back to a closed position (as also described
below).
[0022] The damper 38 may be mounted to the housing 40. The housing
40 can be used to better position the damper 38 on top of the
heater 10, over the exhaust vent 24 and under a hooded outdoor
exhaust vent 39. When the damper 38 is rotated to a closed
position, it, along with the housing 40, can completely or at least
substantially cover the exhaust vent 24. When the damper 38 is
rotated to an open position it will substantially not cover the
exhaust vent 24.
[0023] The damper 38 can be set to the closed position when the
burner 22 is not running to prevent heat loss through the exhaust
vent 24. The damper 38 can be set to the open position when the
main burner 22 is running so that exhaust fumes can flow out of the
exhaust vent 24.
[0024] A first example of a configuration for a valve control unit
52 and damper assembly 54 that can be used with a hot water heater
is shown schematically in FIG. 4. The valve control unit 52 is
coupled to a pilot burner 56, a main burner 58 and a pressure drive
unit 76. Gas is supplied to the control unit 52 via a gas inlet
pipe 60. The control unit 52 operatively allows gas to flow to the
pilot burner 56, main burner 58 and the pressure drive unit 76 via
gas pipes 77. The pilot valve 62 can be maintained open-manually,
e.g., when a person is lighting the pilot burner 56 initially,
and/or by a thermocouple circuit 64 which includes a thermocouple
66 which activates the pilot valve 62 to maintain it open while the
pilot burner 56 is lit. A safety spill switch 68 can be coupled to
the thermocouple circuit 64. The safety spill switch 68 has a
detector (not shown) which can be positioned near the top of the
water heater, but in an area where no exhaust gas should be
present. If the detector detects the presence of exhaust gas, e.g.
by sensing an extremely high temperature, it will cause the switch
68 to open and thereby cause the pilot valve 62 to close,
preventing gas from flowing to the pilot burner 56.
[0025] The control unit also is coupled to a thermostat 72, such as
mechanical thermostat, that can be screwed into the hot water tank.
When the thermostat 72 senses a water temperature that is cold
enough, a diaphragm 74 in the thermostat 72 will push open and
allow gas to flow through the control unit 52 to the main burner 58
as well as a damper drive unit 76. As gas flows to the main burner
58, the main burner 58 will ignite causing the water in the tank to
heat up. At the same time, gas will flow to the pressure operated
damper drive unit 76, creating a pressure on the diaphragm 42 or
bellows (see FIGS. 2 and 3). The pressure should be sufficient
enough to cause the bellows to move from the first position to the
second position, thereby moving the rack and pinion mechanism (see
FIGS. 2 and 3) and causing the damper 82 to rotate to an open
position.
[0026] As shown in FIG. 4, the axle 84 is connected to the damper
82 to create a non-central pivot point. For the circular damper 82
in FIG. 4, the non-central pivot point is created by attaching the
axle 84 slightly off-center, i.e., it does not pass directly
through the diameter of the circular damper 82 such that the
distance D1 is less than the distance D2. By creating a non-central
pivot point, the damper 82 is not balanced on the axle 84.
Accordingly, gravity can assist in rotation of the damper, for
example from the open position to the closed position. This can
help ensure that the damper closes when the main burner 58 is not
operating. In addition, the weight of the rod 44 also assists in
moving the diaphragm 42 back to the first position when gas
pressure is no longer applied.
[0027] When the thermostat 72 reaches a warm enough temperature
that it shuts off the gas supply to the main burner 58 and the
damper drive unit 76, the damper 82 will close due to the lack of
gas pressure on the diaphragm 42, which will return to its first
biased position, but also with the assistance of gravity pulling on
the heavier side (D2) of the damper 82 and the rod 44.
[0028] In this example the procedure for operating the main burner
would generally follow the following steps: lighting the pilot
burner; maintaining the burner as a lit so long a no flue gas is
spilling from the exhaust tube; as long as the pilot light is lit,
and when the thermostat allows gas to flow to the main burner and
drive unit, lighting the main burner and opening the damper;
maintaining the main burner as lit and the damper open until the
thermostat shuts off the supply of gas; and then shutting off the
main burner and closing the damper
[0029] A second example of a configuration of a valve control unit
102 and damper assembly 104 is shown schematically in FIG. 5. The
valve control unit 102 is coupled to a pilot burner 108 and a main
burner 116. Gas is supplied to the control unit 102 via a gas inlet
pipe 107. The control unit 102 operatively allows gas to flow to
the pilot burner 108, main burner 116 and the pressure drive unit
124 via gas pipes 115. The pilot burner valve 106 in this example
can be mechanically held open to light the pilot burner 108 and/or
maintained open by the thermocouple circuit 110 having a
thermocouple 111, similar to the circuit 64 in the first example.
In this example, however, the thermostat 112 is a remote mount
thermostat coupled to a circuit 114. Accordingly, when the
thermostat 112 senses a certain temperature at which the main
burner 116 should light to heat water in the tank, the thermostat
112 activates a switch 118. When the switch 118 is activated, the
circuit 114 is completed that causes a drive unit valve 122 to
open. When the drive unit valve 122 is opened, gas will flow to a
pressure drive unit 124, causing a damper 126 to rotate or move to
an open position (as described above) and to activate a safety
switch 128 when it reaches the open position. When the safety
switch 128 is activated, a second circuit 130 is completed, which
causes the main burner valve 132 to open and supply gas to the main
burner 116. Accordingly, the main burner 116 will not receive a
supply of gas and therefore will not operate unless the damper 126
is open.
[0030] In this example the procedure for operating the main burner
would generally follow the following steps: lighting the pilot
burner; maintaining the burner as a lit; upon a signal from the
thermostat, activating a circuit to open the drive unit valve to
allow gas to flow to the pressure drive unit and opening the
damper; upon opening the damper, activating another circuit to open
the main burner valve and allow gas to flow to the main burner to
heat the water in the tank; and when the water temperature reaches
a predetermined temperature, causing the thermostat to deactivate
the first circuit to prevent gas from flowing to the pressure drive
unit, thereby closing the damper and deactivating the second
circuit to thereby close the main burner valve and turn off the
main burner.
[0031] A third example of a configuration of a valve control unit
152 and damper assembly 153 is shown schematically in FIG. 6. The
valve control unit 152 is coupled to a pilot burner 156, a main
burner 172 and a pressure drive unit 164. Gas is supplied to the
control unit 152 via a gas inlet pipe 157. The control unit 152
operatively allows gas to flow to the pilot burner 156, main burner
172 and the pressure drive unit 164 via gas pipes 171. The pilot
burner valve 154 in this example can be mechanically held open to
light the pilot burner 156 and/or maintained open by the
thermocouple circuit 158 having a thermocouple power pile 159,
similar to the previous examples. In this example, however, like
the first example, the thermostat 160 is mechanical thermostat.
When the thermostat 160 senses a water temperature that is cold
enough, a diaphragm 162 in the thermostat 160 will push open and
allow gas to flow through the control unit 152 to a damper drive
unit 164 causing a damper 166 to move to an open position (as
described above) and to activate a safety switch 167 when it
reaches the open position. When the safety switch 167 is activated,
a circuit 168 is completed, which causes the main burner valve 170
to open and supply gas to the main burner 172. Accordingly, the
main burner valve 170 will not open and the main burner 172 will
not operate unless the damper 166 is in an open position.
[0032] In this example the procedure for operating the main burner
would generally follow the following steps: lighting the pilot
burner; maintaining the burner as lit; when the water temperature
is cool enough, causing the thermostat to allow gas to flow to the
pressure drive unit and open the damper; upon opening the damper,
closing a safety switch to activate a circuit to open the main
burner valve and allow gas to flow to the main burner to heat the
water in the tank; and when the water temperature reaches a
predetermined temperature, causing the thermostat to shut off the
supply of gas to the drive unit thereby closing the damper and
opening the safety switch to thereby close the main burner valve
and turn off the main burner.
[0033] A fourth example of a configuration of a valve control unit
182 and damper assembly 184 is shown schematically in FIG. 7. The
valve control unit 182 is coupled to a pilot burner 186, a main
burner 198 and a pressure drive unit 194. Gas is supplied to the
control unit 182 via a gas inlet pipe 187. The control unit 182
operatively allows gas to flow to the pilot burner 188, main burner
198 and the pressure drive unit 194 via gas pipes 195. The pilot
burner valve 186 in this example can be mechanically held open to
light the pilot burner 188 and/or maintained open by the
thermocouple circuit 190 having a thermocouple 191, like in the
previous examples.
[0034] In this example, the thermostat 192 is mechanical
thermostat. When the thermostat 192 senses a water temperature that
is cold enough, a diaphragm 194 in the thermostat 192 will push
open and allow gas to flow through the control unit 182 to a damper
drive unit 194 and a solenoid valve unit 196 coupled to the main
burner 198. The gas flowing to the pressure drive unit 194 causes a
damper 200 to open (as described above) and also to activate a
safety switch 202. When the safety switch 202 is activated, a
circuit 204 having a thermopile 205, which works in conjunction
with the thermocouple 191, is completed, and causes a valve 206 in
the solenoid valve unit 196 to open and allow gas to flow to the
main burner 198. Accordingly, the solenoid valve unit valve 206
will not open and the main burner 198 will not operate unless the
damper 200 is rotated to an open position.
[0035] In this example the procedure for operating the main burner
would generally follow the following steps: lighting the pilot
burner; maintaining the burner lit; when the water temperature is
cool enough, causing the thermostat to allow gas to flow to the
pressure drive unit and to a main burner valve unit; causing the
pressure drive unit to open the damper, and upon opening the
damper, closing a safety switch to complete a circuit to cause a
valve in the main burner valve unit to open the supply gas to the
main burner to ignite the burner and heat the water in the tank;
and when the water temperature reaches a predetermined temperature,
causing the thermostat to shut off the supply of gas to the
pressure drive unit and main burner valve unit, thereby closing the
damper and opening the safety switch to thereby deactivate the
circuit and close the main burner valve, to stop the supply of gas
to the main burner, thereby turning the main burner off.
[0036] While the foregoing has described what are considered to be
the best mode and/or other examples, it is understood that various
modifications may be made therein and that the technology disclosed
herein may be implemented in various forms and examples, and that
they may be applied in numerous applications, only some of which
have been described herein. It is intended by the following claims
to claim any and all modifications and variations that fall within
the true scope of the advantageous concepts disclosed herein.
* * * * *