U.S. patent number 3,765,398 [Application Number 05/298,971] was granted by the patent office on 1973-10-16 for heating apparatus for outdoors operation.
This patent grant is currently assigned to Carrier Corporation. Invention is credited to Richard L. Morris.
United States Patent |
3,765,398 |
Morris |
October 16, 1973 |
HEATING APPARATUS FOR OUTDOORS OPERATION
Abstract
The casing of a rooftop heating apparatus is formed with plenum
and heat exchanger compartments separated by a partition formed
with a passage for air flow from the plenum compartment to the
burner in the heat exchanger compartment. Damper means is mounted
in the air flow passage of the partition and is normally positioned
for maximum air flow with the plenum pressurized by a constant
speed blower. The intake of the blower is subject to varying wind
pressures. The damper means is responsive to air pressure in the
plenum to vary the areas of the air flow passage proportionate to
the pressure in the plenum and accordingly, to maintain the air
flow to the burner at a predetermined level, whereby the burner
operation is not adversely affected by gusts of wind.
Inventors: |
Morris; Richard L.
(Indianapolis, IN) |
Assignee: |
Carrier Corporation (Syracuse,
NY)
|
Family
ID: |
23152788 |
Appl.
No.: |
05/298,971 |
Filed: |
October 19, 1972 |
Current U.S.
Class: |
126/110B;
137/517; 431/20 |
Current CPC
Class: |
F24H
9/2085 (20130101); F24H 3/065 (20130101); Y10T
137/7869 (20150401) |
Current International
Class: |
F24H
9/20 (20060101); F24H 3/02 (20060101); F24H
3/06 (20060101); F24h 003/06 () |
Field of
Search: |
;126/11B,11R,116R
;98/119 ;137/517,521 ;431/20 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wayner; William E.
Assistant Examiner: Tapolcai, Jr.; William E.
Claims
I claim:
1. Heating apparatus for outdoors operation comprising a casing
formed with a heat exchanger compartment and a plenum compartment,
said compartments being separated by a partition, a heat exchanger
mounted in said heat exchanger compartment, a burner associated
with said heat exchanger for heating the same, a constant speed air
blower having an intake communicating with the outdoor atmosphere
and subject to varying wind pressure, said blower being operable to
discharge air into said plenum compartment, a stack connected to
said heat exchanger for the conveyance of products of combustion
from said heat exchanger to the exterior of said casing, a bypass
means extending from said plenum compartment to the exterior of
said casing for the flow of air therefrom, an air flow passage
extending through said partition from said plenum compartment to
the burner in said heat exchanger compartment, an air flow control
damper means mounted in said air flow passage, said damper means
being movable from normal maximum air flow position to minimum air
flow position, such movement being proportionate to the variation
in wind pressure at the intake of said blower, said damper being
operable during such movement to maintain the volume of air flow
through said air flow passage at a predetermined level.
2. Heating apparatus as set forth in claim 1 wherein said burner is
a gas fired burner.
3. Heating apparatus as set forth in claim 1 wherein said bypass
means communicates with said stack.
4. Heating apparatus as set forth in claim 1 wherein said partition
is disposed vertically in said casing and said air flow passage is
disposed upwardly from the bottom of said plenum compartment and
extends transversely thereof, said damper means consisting of an
inverted "V" shaped member, support means pivotally supporting said
member in said air flow passage at the bight of said member for
free pivotal movement, with the sides of said member diverging
downwardly from said pivot and being normally positioned in spaced
straddling relation to the bottom side of said air flow passage
whereby the upstream side of said damper member is moved toward
said partition for reducing the area of said air flow passage
proportionate to an increase in the air pressure from normal in
said plenum.
5. Heating apparatus as set forth in claim 4 and including stop
means for limiting movement of said upstream side of said damper
toward said partition.
Description
BACKGROUND OF THE INVENTION
Presently, in many instances air conditioning and heating apparatus
is mounted on the rooftops of buildings, especially dwellings. In
most cases, the heat exchanger of the apparatus is fired with a gas
burner. It is well known that gas burners are adjusted as to
require a flow of air of predetermined value for proper
combustion.
In the arrangement of my invention, the air flow for supporting
burner combustion is created by a blower operated at constant
speed. However, because the apparatus is located out of doors, the
output of the blower varies to a great extent due to gusts of wind
entering the intake of the blower. Such sudden increases in the
flow of air to the burner can adversely affect the operation of the
burner, even to the extent of extinguishing the burner flame.
Many arrangements have been suggested for overcoming the problem
above referred to. However, they involve complicated and expensive
mechanisms which require periodic maintenance.
This invention has as an object a heating apparatus suitable for
rooftop operation wherein the air supplied to the gas burner is
maintained at a desired, predetermined level, regardless of ambient
conditions.
SUMMARY OF THE INVENTION
The casing of the apparatus is formed with a plenum compartment and
a heat exchanger compartment in which there is mounted a gas fired
heat exchanger. A partition separates the compartments and is
formed with a passage for the flow of air from the plenum to the
heat exchanger compartment. Normal air pressure is maintained in
the plenum by a constant speed blower and a bypass is provided for
bypassing a portion of the air in the plenum compartment to the
exterior of the casing.
To maintain the air flow to the burner consistently at a desired
level, a damper is mounted in the partition passage and is
operative to vary the area of the passage in response to and
proportionate to the air pressure in the plenum.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view schematically illustrating a heating apparatus
embodying my invention, one side of the casing being removed;
FIG. 2 is an enlarged perspective view of the damper structure;
and
FIG. 3 is a view looking to the left in FIG. 2 showing the damper
in closed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The heating apparatus comprises a casing having side walls 10, 11;
end walls 12, 13; a bottom wall 14 and a top wall 15. A vertically
disposed partition, consisting of an upper section 17 and a lower
section 18, divides the casing into a plenum compartment 20 and a
heat exchanger compartment 21. The heat exchanger 22 is mounted in
the heat exchanger compartment 21 and is fired by a gas burner 23
supplied with gas through a conduit 24.
An air intake 25 communicates with the area about the heat
exchanger 22, the heated air being discharged through a conduit 28
in the top wall 15. The flow of air is indicated by the arrows
30.
A blower 31 is mounted in the plenum compartment 20 and is powered
by a constant speed motor 33. The intake 35 of the blower
communicates with the atmosphere. The blower functions to discharge
air into the plenum compartment. Preferably, the casing is formed
with a bypass extending from the plenum compartment 20 to the
atmosphere. In the arrangement shown, a stack is provided for
conveying products of combustion from the heat exchanger 22 to the
atmosphere. As shown in FIG. 1, the bypass is incorporated in the
stack structure. A tube 37, having communication with the heat
exchanger 22, extends through the partition section 17 toward the
end wall 12. A larger tube 40 has a horizontally disposed portion
extending from the partition 17 outwardly through the end wall 12
for communication with the vertically disposed portion 41,
communicating with the atmosphere. The tube 40 is arranged in
spaced concentric relation to the tube 37. A portion of the
underside of the tube 40 is cut away. In FIG. 1, the bottom side of
the tube 40 terminates at 43. This presents an opening to the space
between the tubes 37 and 40 through which air flows from the plenum
20 as indicated by the arrows 47, the flow continuing about the
exterior of the tube 37 as indicated by arrows 48 to the vertical
portion 41 of the stack.
The lower edge 50 of the upper partition section 17 is positioned
in upwardly spaced relation to the lower section 18. The partition
sections 17, 18 extend transversely of the casing between the side
walls 10, 11. The space between the partition sections 17, 18
provides a passage for the flow of air from the plenum chamber to
the heat exchanger compartment.
A damper means is mounted in the air flow passage and functions to
automatically maintain the flow of air through the passage at a
predetermined level, regardless of gusts of wind passing through
the blower inlet 35.
The damper 60 is formed of sheet material and is of inverted "V"
configuration. The damper 60 is pivotally supported on a member 61
extending transversely between the walls 10, 11 of the casing. The
sides 62, 63 of the damper diverge downwardly from the support
pivot 61 and terminate a distance below the lower edge 51 of the
air flow passage. The upper and lower portions 17, 18 of the
partition, above and below the air flow passage, are arranged in
vertical alignment. The sides 62, 63 of the damper are of equal
size whereby the sides of the damper are normally positioned in
spaced straddling relation to the lower portion 18 of the partition
as shown in FIGS. 1 and 2. The air flow from the plenum, indicated
by the arrows 67, FIG. 1, strikes against the upstream side 62 of
the damper and passes upwardly under the lower edge of the side 62
and over the edge 51 at the bottom of the air flow passage, as
indicated by the arrows 70. The air flow over the edge 51 strikes
against the inner surface of the side 63 of the damper. With the
damper positioned as shown in FIGS. 1 and 2, the air flow to the
burner is at a level providing correct combustion for heating the
heat exchanger 22.
A gust of wind passing through the inlet 35 of the blower will
increase the output of the blower, and the pressure in the plenum
compartment 20. This increase in pressure acting against the outer
side of the damper leg 62, and on the inner surface of the damper
leg 63, will cause the damper to swing in a counter-clockwise
direction, referring to the drawings, moving the side 62 of the
damper toward the passage edge 51, and accordingly reducing the
flow of air between the side 62 of the damper and the lower portion
of the partition. This movement of the damper will be proportionate
to the rise of pressure in the plenum compartment because of the
bypass through the space between the stack tube 40 and the inner
tube 37.
The air flow through the bypass and the weight of the damper 60 are
coordinated relative to the output of the blower 31 such that in
the absence of any wind pressure at the inlet of the blower 31, the
damper hangs in the straddling position shown in FIGS. 1 and 2, and
air flow to the burner is at the proper level. However, with wind
pressure at the inlet 35 of the blower, causing an increase in the
pressure in the plenum chamber 20, the damper 60 will be moved in
counterclockwise direction to reduce the spacing between the lower
portion of the side 62 of the damper and the lower partition
section 18. In other words, the air passage will be reduced in area
proportionate to the pressure in the plenum 20. Accordingly, the
air flow to the burner 23 will be maintained at the proper
level.
Stop means is provided to prevent the side 62 of the damper from
moving into direct contact with the lower portion 18 of the
partition to completely close the air flow passage. This stop means
may be conveniently provided by one or more stops 80 fixed to the
upstream side of the partition section 18.
While I have described the preferred embodiments of my invention,
it is to be understood that the invention is not limited thereto,
but may be otherwise embodied within the scope of the following
claims.
* * * * *