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Патент USA US3027899

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April 3, 1962
3,027,889
A. E. KRAUSZ
AIR HEATER WITH AIR FLOW SENSING DEVICE
Filed Nov. 12, 1957
'
2 Sheets-Sheet 1
iii
INVENTOR.
Q/Zazz
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April 3, 1962
A. E. KRAUSZ
3,027,889
AIR HEATER WITH AIR FLOW SENSING DEVICE
Filed Nov. 12, 1957
2 Sheets-Sheet 2
49
-Z' Z. " Z
49’ 52/012
BY
‘
’
INVENTOR.
jiffawj
United States Patent 0 M
1
3,027,889
Patented Apr. 3, 1962
2
FIGURE 2 is a detail cross-sectional view of the hori
3,027,889
AIR HEATER WITH AIR FLOW SENSING DEVICE
Allan E. Krausz, % The Siegler Corp, Centralia, 11].
Filed Nov. ,12, 1957, Ser. No. 695,814
3 Claims. (Cl. 126—110)
This invention relates to heating equipment, particu
zontal hot air ‘duct of the unit, by which heated air may
be projected in a horizontal stream across the surface
of the floor upon which the unit is supported;
FIGURE 3 is an exploded view of the several com
ponent parts of the thermostat mechanism utilized in
connection with the device;
FIGURE 4 is a plan view of the thermostat control
larly to a control device for regulating the supply of fuel
head;
to the burners of heating equipment.
FIGURE 5 is a side elevational view thereof showing
One object of the present invention is to provide a 10
the control head of the thermostat at?xed to the oil valve
forced draft heater wtih a new and improved device for
of the heater with parts broken away and in section to
controlling the fuel flow and automatically reducing the
illustrate the oil ?ow regulating valve;
fuel supply to a safe level in the event of failure of the
FIGURE 6 is a detail sectional view taken substantially
forced air supply.
A more speci?c object of the invention is to provide 15 on the plane of the line 6-—6 of FIGURE 4;
FIGURE 7 is ‘a detail ‘sectional view taken substantially
an air sensing mechanism which has no pressure-respon
on the plane of the line 7—7 of FIGURE 4.
sive diaphragms, vanes, sail switches, or other moving
FIGURE 8 is a sectional View taken along line 8—8 of
parts in the air stream of the heater. In prior art
FIGURE 4.
heaters, such mechanisms have commonly employed
The forced air heater illustrated in FIGURE 1 of the
pressure-responsive vanes and the like as, for example, 20
present drawings is a home unit of the oil burning type
shown in U.S. Patent Re. 22,276, reissued February 23,
having one blower to supply both the forced draft to
1943, to Arthur N. Schreuder, and U.S. Patent No. 2,251,
the burner as well as circulating the heated air, although
055, issued July 29, 1941, to David J. Howard, et al. The
it will be understood that the principles of the present
very small pressures utilized in supplying draft to a
burner required that the prior art pressure-sensitive con 25 invention are equally applicable to heaters designed for
other uses or using other types of fluid fuels. As illus
trols have relatively large vanes or diaphragms in the air
trated, the heater consists of an exterior housing or shell
stream to increase the force available to operate the
having a front wall 10, back wall 111 and side walls of
control. However, the ungainly size of these vanes or
diaphragms required excessive space. As a result of 30 sheet metal which may be of “wrap around” construction,
with the lowermost edges of the walls ?anged at 12 and
efforts to reduce the size of the vanes or diaphragms,
13 to rest on a floor surface 14. The heater is preferably
these prior art controls proved unreliable and erratic
provided with an upper air grille 15 at the top and lower
in operation and were generally unsatisfactory in use.
air grille 16 in the front wall adjacent the bottom of the
The present invention provides a control mechanism
which is more positive and dependable in operation than 35 unit. Under normal operation air is drawn inwardly
through the upper grille, heated in the heat exchanger
types heretofore devised, has ‘a minimum of linkage and
tubes, passed through the blower housing to the lower
moving parts, and is not subject to clogging by accumu
air duct, and directed outwardly through the lower grille.
lation of foreign matter in the air ducts.
The internal structure comprises a heating unit within
A further object of the invention is to provide a
heater having the control device as indicated above oper 40 the shell 10 and spaced from its walls by air spaces and
suitable insulation, not shown. The heating unit includes
ating entirely independently of all other control units
a cylindrical ?re pot 17 which, as shown, may be pro
of the heater, so that restoration of the forced air sys
vided with disc-like ba?ies 18 and 19 arranged above a
tem will automatically render the heater responsive to
bottom plate 21 having an integral peripheral ?ange 22
the in?uence of its normal controlling devices without
?tted to the bottom of the cylindrical walls of the ?re
requiring any resetting by the operator.
pot and thus forming an imperforate oil receptacle. The
Yet another object is to supply the correct amount of
?re pot is surrounded by an air jacket 23 and a number
fuel and air to a cold burner automatically when initially
of small air inlet ports 24 are provided in the peripheral
starting the heater. The operator does not have to make
walls 17 of the pot to permit inward ?ow of air from
a starting fuel setting and then wait until the burner
the jacket 23 to the ?re. The ?re pot 17 has its top
becomes heated before making his desired operating
plate 25 directly below a combustion chamber having a
setting. Failure to observe this waiting period before
bottom 26, top 27 and vertical walls 28. An outlet con
large quanti?es of fuel are fed to a cold burner could
nection 29 is provided at the top of the back wall for
cause an explosive mixture due to the puddling of the
connection with a suitable flue.
oil or incomplete combustion of the fuel.
A heat exchanger is provided within the combustion
Another object is to provide a device accomplishing 55 chamber.
The heat exchanger includes a plurality of
these objects that is simple and rugged in design and
vertical air tubes 31 in side-by-side relation and extend
construction, yet reliable ‘and effective in operation.
ing between the top wall 27 and the bottom wall 26 of
The principles of the present invention are of particu
the combustion chamber. The upper ends of each of
lar advantage in warm air space heaters of the type
the tubes open to the air space 32 immediately below the
having forced air supplied to the burner to provide suf 60 upper air grille 15, and the lower ends of the tubes open
?cient oxygen to insure complete combustion and having
into a rectangular air box 33 which is in turn connected
forced circulation of heated air into the living area.
to the inlet 34 of a centrifugal fan in a blower housing
The present invention provides for control of the fuel
35. The fan is driven by the motor 36 and the blower
flow to the burner by an element sensitive to the move
ment of warm air in the outlet passage of the heater.
housing has an outlet passage 37 interconnected with the
65 enlarged end of an air discharge duct 38 extending hori
The unusual results following from this unique ar
zontally across the heater below the ?re pot 17 and slight
rangement will be best understood in connection with the
ly above the ?oor surface 14 to deliver heated air (as
description of the preferred embodiment of the inven
shown by the arrow 44) to the lower grille 16 in the
tion as illustrated in the attached drawings wherein:
front wall 10. The air discharge duct 38 is provided
FIGURE 1 is a cross-sectional view through a forced 70 with a branch conduit 39 leading to the air jacket 23
‘around the ?re pot. In the preferred practice of the
air space heating unit designed for burning oil and em
invention, a partial ba?ie 41 is provided in the duct 38 to
ploying the air failure device of the present invention;
3,027,889
9
#3
direct a portion of the air from the blower into the ?re
pot jacket.
Fuel is supplied to the ?re pot through an oil control
valve housing 42 interconnected to the oil receptacle 21
of the fire pot by a feed pipe 43. The oil valve may be
of any appropriate type, ordinarily having a ?oat cham
ber fed from any appropriate oil supply, a regulating
4
falling below the lower limit of operation of the control
device, which may be about 110° F. As bulb 47 rapidly
cools, it causes the ?uid therein to contract, reducing the
pressure in pressure-responsive element 52 allowing the
bellows 53 to expand, thus causing the plate 55 under
pressure of spring 57 to press the valve pin 46 down
wardly into low ?re position. Suf?cient oxygen is avail
able for complete combustion of the fuel delivered to the
valve 70 (FIG. 5) controlling the ?ow of oil to the burner,
combustion chamber when the metering valve is in its
and a manually adjustable knob 45 to selectively deter
mine the rate of ?ow from the chamber '72 through pipe 10 low ?re position.
The heater will operate in this low ?re position until
43 to the burner.
the cause of the blower’s ceasing operation is remedied
The fuel oil supplied to the burner thus ?ows through
irrespective of the setting of the manual knob 45. Upon
the feed pipe 43 into the ?re pot, with the rate of flow
blower resumption, hot air is again forced over the ele
of the fuel controlled or varied by the manually operable
ment 47, expanding the ?uid therein to lift the plate 55
valve knob 45. The operation of the oil ?ow regulating
from the control pin 46. This removes the overriding
valve 70 is subject, however, to overriding control by the
control of the safety control and restores regular heater
device disclosed herein, arranged to bear on an auxiliary
operation, with normal control of the metering valve by
control pin 46 on the valve housing 42 (FIGURES 5 and
the manual adjusting knob 45.
7) to restrict the valve to its minimum rate of fuel ?oW
It will be obvious to those skilled in that art that al
in the event of any failure of the forced air supply,
though I have described an adaptation of the invention
whether occasioned by power failure, blown fuse, motor
as applied to the well known constant level valve, the
burn out, or any other cause.
invention may be carried out by the use of a separate
The present invention includes a device that is sensitive
to the ?ow of heated air to control the oil ?ow, with a
thermo-responsive bulb 47 in the duct 38 between the
warm air responsive valve placed at any suitable point
sive element is arranged to lift the outer end of the rocker
For one thing, the warm air sensing element renders the
in the fuel line.
It will also be evident that the simple hydraulic valve
branch conduit 39 and the lower grille 16. The bulb is
actuator may be used to operate an electric switch which
preferably mounted at an angle, with its capillary tube 48
in turn may control an electric circuit to a solenoid valve
extending from its lowermost end to a head assembly in
without avoiding the scope of invention.
cluding a mounting plate 49 with a pressure-responsive
element 52 riveted thereto. The mounting plate 49 is 30 It is seen that the present invention functions to reduce
the fuel oil fed to the burner automatically upon any
secured to the valve housing 42 by appropriate screws 51.
cause of blower failure, by sensing the cessation of the
The chamber of pressure element 52 is ?lled with thermo
heated air ?ow, and also functions to restore full heater
static ?uid surrounding internal bellows 53, supported by
operation when the blower action resumes.
a backing screw 54 carried on a valve-actuator plate 55
This achieves important new results in several respects.
pivoted on the plate 49 by a pin 56. The pressure-respon
fuel control apparatus sensitive to the ?ow of air through
the circulatory system of the heater without the need of
pressure-sensitive diaphragms, sail switches or other prior
rock the plate 55 in a counter-clockwise direction around 4 O. conventional air-responsive devices. It follows that the
disclosure of the present invention is much less subject
the pivot 56 and press the control pin 46 downwardly
to malfunction or failure of operation than any apparatus
whenever the bulb cools below a predetermined minimum
employing moving parts in the air stream, where their
temperature. In the event that the bulb 47, capillary tube
plate 55 against the force of the leaf spring 57 when the
temperature-responsive bulb 47 is at normal operating
temperature of the unit, but to permit the leaf spring 57 to
movement may be impeded by accumulation of dust or
48 or bellows 53 should be damaged, the spring 57 will
move the plate 55 downwardly and decrease the ?ow of 45 lint. The prior conventional air sensing devices are
erratic and unreliable in operation due to their inherent
the oil.
The blower and fuel metering valve may be intercon~
size and lack of sensitivity. With the present invention,
nected in a manner well known in the art, so that the
high reliability and dependability of control may be
rate of air flow is proportioned by the rate of fuel ?ow
achieved.
when the valve is in any of its selected positions afford 50
Having thus described my invention, what I claim as
ing high ?re for the burner,
new and desire to secure by United States Letters Patent
The force circulation of air through the heat exchanger
1s:
by operation of the blower is accompanied by increased
1. A heater and control system therefor comprising a
air ?ow into the ?re box and combustion chamber, and
combustion chamber, a pot type burner within said
in normal operation the quantity of air passing through 55 chamber which is adapted to operate on a low ?re and a
conduit 39 due to the blower action in forcing air through
high ?re, means for supplying fuel to said burner includ
the output duct, is su?icient to combine with the maxi
ing ?ow regulating means for controlling the amount of
mum fuel delivered to the combustion chamber to insure
fuel being supplied to said burner from low rate to high
complete combustion of the fuel.
rate to provide from low to high ?re, and means for over
If for any of ‘a number of reasons, such as blower 60 riding said regulating means to selectively provide said
motor failure, power failure, or the blowing of a fuse, the
blower ceases operation, the forced air supplied to the
combustion chamber also ceases.
low ?re and permit said high ?re at the burner, a heat
exchanger communicatively associated with said combus
If no overriding con
tion chamber, conduit means beneath the burner and heat
trol of the fuel supply was provided, there would be no
exchanger in ?uid communication with said heat ex
decrease in the supply of fuel fed to the combustion cham 65 changer and terminating at one end in a hot air exhaust
ber, and the incomplete combustion resulting from the
opening at the outer surface of the heater, blower means
excess proportion of fuel to oxygen would allow soot to
form and possibly allow unburned fuel fumes to leave
the combustion chamber as well as the possibility of an
disposed in communication with said heat exchanger and
said conduit means and operative to cause air to ?ow
downwardly through said heat exchanger and out the
explosive mixture forming in the combustion chamber 70 exhaust opening in said conduit means, means shunting
when the blower starts again. The present invention pro
vides this overriding control which reduces the fuel sup
plied to the chamber on any cessation of the blower
a portion of the ?ow of air from said conduit means to
said burner and affording natural draft to said burner
when said blower means is inoperative, an air-?ow sens
ing device comprising a thermo-sensitive element disposed
operation. In this event, the lack of heated air passing
over element 47 in the outlet results in the bulb’s rapidly 75 in said conduit means in shielded relation to the radiant
3,027,889
6
eluding ?ow regulating means for controlling the amount
of fuel supplied to said burner from low rate to high rate
to provide from low ?ame to high ?ame level, and means
‘for overriding said regulating means to selectively pro
vide said low ?ame and permit said high ?ame level at
the burner, an indirect heat exchange system communi
heat from said burner, said sensing device being opera
tively connected with said overriding means so that tem
perature of the air in said conduit surrounding said ele
ment below that provided by the low ?re with the blower
means in operation causes said overriding means to pro
vide said low rate, and so that temperature of said air in
catively associated with said combustion chamber and
said conduit surrounding said element and equal to that
comprising a vertically extending heat exchanger includ
provided by low ?re with said blower means in operation
ing a plurality of tubes having communication at their
causes said overriding means to permit supply of fuel at
10 upper ends with the air space above the upper portion
said high rate.
of said combustion chamber, conduit means ‘disposed be
2. A heater and control system therefor comprising a
low said combustion chamber and in communication with
combustion chamber, a pot type burner within said cham
the lower ends of said tubes, said conduit means terminat
ber which is adapted to operate on low ?re and high ?re,
ing in an exhaust opening at the outer surface of the
means for supplying fuel to said burner including ?ow
regulating means for controlling the amount of fuel being 15 heater, and a blower associated with said heat exchanger
and conduit means which is adapted to effect a ?ow of
supplied to said burner from low rate to high rate to
provide from low to high ?re, and means for overriding
said regulating means to selectively provide said low ?re
and permit said high ?re at the burner, a vertically ex
tending heat exchanger communicatively associated with
air downwardly through said tubes and out said exhaust
opening, additional conduit means communicatively con
nected between said ?rst mentioned conduit means and
20 said burner in said combustion chamber to provide a
gravity ?ow of air into said chamber through said exhaust
opening when said blower is inoperative and to shunt a
portion of the ?ow of air from said blower to said cham
ber when said ‘blower is operative, and an air ?ow sensing
means terminating at one end in a hot air exhaust open
ing at the outer surface of the heater, blower means dis 25 device comprising a thermo-sensitive element disposed in
said ?rst mentioned conduit means between said exhaust
posed in communication with said heat exchanger and
opening and said additional conduit means and in a
said conduit means and operative to cause air to ?ow
said combustion chamber, conduit means in communica
tion with said heat exchanger and disposed at a lower
level than said burner and heat exchanger, said conduit
downwardly through said heat exchanger and out the
shielded position relative to said burner, heat exchanger,
and combustion chamber, said sensing device being opera
exhaust opening of said conduit means, means connected
tively connected with said overriding means so that air
between said conduit means and said combustion cham 30 temperature in said ?rst conduit means surrounding said
ber for shunting a portion of the ?ow of air in said con
thermo-sensitive element below that provided therein by
duit means to said burner and for affording natural draft
the low ?ame level with the blower in operation causes
in said combustion chamber when said blower means is
said overriding means to provide said low rate, and so that
inoperative, and an air-?ow sensing device comprising a
35 temperature of the air in said ?rst conduit means which is
thermo-sensitive element disposed in said conduit means
adjacent said exhaust opening, said sensing device being
equal to or greater than that provided by low ?ame opera
tion with ‘said blower means in ‘operation causes said over
operatively connected with said overriding means so that
riding means to permit the supply of fuel at said high
temperature of the air in said conduit surrounding said
rate.
>
element below that provided by the low ?re with the 40
References Cited in the ?le of this patent
’ ’
blower means in operation causes said overriding means
to provide said low rate, and so that temperature of the
air in said conduit surrounding said element and equal
to that provided by low ?re with said blower means in
operation causes said overriding means to permit supply 45
of fuel at said high rate.
3. A heater and control system therefor comprising a
combustion chamber, a pot type burner in ‘said chamber
which is adapted to operate with natural draft flow of
air at a low ?ame level and with forced draft at a high 50
?ame level, means for supplying fuel to said ‘burner in_
UNITED STATES PATENTS
1,681,421
McCabe _____________ __ Aug. 21, 1928
1,985,799
Scheifele _____________ __ Dec. 25, 1934
2,157,109
2,282,197
2,331,219
2,356,705
2,428,867
2,477,804
Bell _________________ __ May 9,
Maynard ______________ _.. May 5,
Mueller et al. __________ .._ Oct. 5,
Siegler et al ___________ _._. Aug. 22,
De Lancey ___________ .. Oct. 14,
Huber _______________ _._. Aug. 2,
1939
1942
1943
1944
1947
1949
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