US2410548A - Heating apparatus - Google Patents

Description

Nomfia 1946. H. J. DEN. c coLLuM 2,410,548

HEATING APPARATUS Filed July 6, 1942 3 Sheets-Sheet 1 Index/Ear #ffielI/j/C @Zlaem Nov. 5, 194%; 55 MCCQLLUM 2,410,548

HEATING APPARATUS Filed July 6, 1942 3 Sheets-Sheet 2 l l f Nov. 5, 1946. H. J,,DE N. MccoLLuM 2,410,548

HEATING APPARATUS Fil ed July 5, 1942 s Sheets-Sheet s u LT. u 7 H u {m N m 2 r UT 555; itfm v invention relates generally to liestirigs p psrstus, sud. more particulerly to improvements in hesters of the internal combustion type for use in heating aircraft, buses, trucks, and the like.

It is an object. oi my invention to provide an improved form of heater for securing emcient combustion of a. use of liquid fuel curl air, and securing emcieut trensier oi best to the sir to he hesteal.

A further object of my invention is to prcvicle an improved form of heating epp'crstus which is compact, is of simple construction, curl may be economically manufactured.

Other objects will appear from the following description, reference being heel to the ecccm pausing drawings, in which:

his. 1 ice diesrexumstic view illustrating the heating eppez'stus installed upon sin eirpleiie;

Fig. 2 is s central verticsl sectional View through c portion of the hcster;

Fig. 3 is e hcrizoutsl sectional View tehen on the line l--ll of Fig. 2;

Fig. is e, fragmentary sections! view taken on the 51-41 of Fig. 2;

5 is s central vertical sectional view oi e modifies". term. of the heater; and,

his. 6 .isc licriscntel sectional View tslseii on the line 63 6 cf Fig. c.

he lhustrcted in Fig. l, the heating epceectus is shcwu instslled upon an aircraft. The heel; exchanger end combustion chamber ere euclcsetl in e. casing till, the combustible mlzmure heme supplies; to the combustion chember from s. csr

buretcr the jet of which is'ccmiecteti tc s float bowl tenls 2 3, the pressure in'which is main-- teineci shove stmcspheric by the vclccity oi the air entering an orifice 2c in 9, tube 253. This orifice is so lccsted that the pressure within the fleet howl chamber 26 is meiuteiiiec suilicieritly W to assure flow oi the liquid fuel from thciioct howl chamber 2% to the csrliuretcr 22 through c. tube 8%? and to cause the "fuel tc he etcmisccl cs 3. De N. ellcll s case, us; 'llhc seicli he i. he N. rec

e, ices, Serfisl rec. elects (cl. sense I In some instances, the pipe it may lead to the cabin of an airplane which is to he superchsrged,

Q 'in which event the blower 85 may be the cabin ill taupercliusrser.v The exhaust gases from the heater (luit is, which leads to a vent opening ii in the external well cf'the airplane cabin or wing, pref ersloly st e. point at which a, partial Vacuum is present when the aircraft is in flight.

The blower 531i mew be driven by as suitable motor es, which may else he used to drive the centrifugal blower or separate striving motors msy he ueecl. in some lustslletlocs, the blower as euel pump 3% may he drives from the engine of the sir-craft, end in other lustslletiohs, the combustilcle mixture msy he drawn ircm the engine supercherser, to avoid the necessity of peovlriing the carburetor still blower El i. llrirler other conditions, it single blower mey he used to supply sir under pressure to the carburetor es well for forcing the sir to be heated through the heat exchcneer.

(ill

it is clischsrged from the orifice 8i loceteu st I the upper eml of the pipe 3h the thrcst oi the Venturi=shupecl passe-sewer through the carburetor. Fuel is supplied to the host howl tank 2 3 through c conduit 33 from shy suitable source. The fuel is preferably sesoline, but may be shy other suitable hydrccsshou fuel.

Flew through the carburetor Ell is induced by is positive displacement pump or slower ill, the

inlet of which is connected to the carburetor 2 As best shcsm i'u 2, the casing 526 is formed in two halves it}, ll. which ere preferably of irlehticzsl slices curl have their externsl flanges ill} secured tcecther by hclts Ell. Within the cesihe'fifi l is lee-steel. sccmhueticn chamber and heat exchanger ease-cuticle comprising e combustion chamber icrmirig e combustion chemlier The wells cf the chamber @5 are proviclecl with cu i sheeecl liners curl prelershly mettle of reisectcry ceramic material, the upper liner having perioreticsie formed in the crliuclrlcel well thereof.

The lutluctieh tube eiztemls intc c suitable opening ice-meal in the hcttcrh of the casting .ericl through liner heirs; clumped is. pcsithan by sleeve nut The end of the inductiers tu'ce within the ccmhosticsi chamber lies its licre enlarged to receive as cusp shsperl mix= ture spresclcr the wells oi the curl of this tube being pierced fcrei ports for the discharge of ccmbustihle mixture from the induction. tube 32 into the cembusticn chamber. These ports (is ere preferably shspeel to secure generally tensemi-lei discharge of the mixture into the combus= ticzci chemise? so that the mixture will flow through thi chamber in turbulent generally helical Rleirlly secllied to the end of the induction tulle as by welding. is s rclgiiiter 3, which is more fully disclosed in my cmsemiliig application Serial No. ililllill, filed September 8, lll il.

An ignites plug t ll is threaded into the com hustion chamber casting 52 extends partially into stable opening formed in the liner es,

this plus inclurlihs' c resistance wire isniter it,

the e, wire it to one teinel of e.

source of energizing current, the other terminal of the source'being grounded to the combustion chamber casting 52.

Rigidly secured to the combustion chamber casting 52 is a heat exchanger assembly comprising a pair of generally circular plates I2 and I4,

formed in the opposed surfaces of the plates l2 and I4. The space between the liner 58 and the perforated ring I8 is preferably filled with a crushed refractory ceramic material 11.

The plates 72 and I4 are preferably castings 7 having radial fins 80 formed integrally therewith and which project outwardly so as to have their edges closely adjacent the casing halves and 41. It will be noted that the exhaust conduit 40 is secured in the ring I6 and extends through the casing 20. rings I and I8 constitutes a passageway for the flow of gases of combustion to the exhaust pipe 40.

In operation, the fuel mixture supplied by the carburetor 22 is forced under pressure by the blower 34 into the combustion chamber SI through the induction tube 32, where, at the starting of operation of the heater, it is ignited by the igniter 68. It will b noted that the ports 92 are located just above the bottom of. the liner 56, so that during starting, any unvaporized fuel will tend to collect around the ports 62, where the incoming mixture of fuel and air will tend to pick up droplets of fuel and thus enrich the incoming mixture to make it more easily ignite.- ble. After the mixture in the combustion chamber has been ignited, the igniter is deenergized by suitable well known thermostatic control means, and thereafter, the heater will operate continuously without further attention.

While operating, the reigniter 64 becomes heated to a temperature sufllciently high to reignite the fuel mixture should the flame become accidentally extinguished. The gases of combustion flow outwardly through the perforations 59 in the inverted cup-shaped liner 58, pass through the crushed ceramic filler I1, and thence through the ports in the-ring I8 and passageway I9 to the exhaust pipe 40.

The space within the ring I8, which is filled with the ceramic material I'I, acts as a muiiler to retard-the generation of oscilations and noise. This ceramic material becomes incandescent during normal operation and serves as an emcient means to radiate heat to the plates I2 and I4 and to distribute the heat to the flowing gases,

, insuring combustion of any fuel which is not completely consumed in the combustion chamber. The heat from plates I2 and I6 is rapidly conducted to the fins 80 and thence transferred to the air to be heated which is forced to flow past the fins by the blower 35. The heat exchanger, formed mainly by the plates I2 and I4 and the fins 80, constitutes a very emcient means for transferring the heat from the gases of combustion to the air. The flow of the products of combustion of the heat exchanger is suiliciently slow that suflicient time is'available for the transfer to the plates I2, ll, of the main portion of heat content of the gases of combustion. The flow of airpast the fins 80 is relatively rapid, especially at the inlet portion of the casing 20 as well as at the outlet portion thereof, so that the heat is The annular space I9 between the rapidly transferred from the fins 80 to the air to In the modification of the invention shown in Figs. and 6, the casing 20 is of generally the same conformation as that shown in Figs. 1 and 2, and the parts are adapted to be used in conjunction with any suitable fuel and air supply means, such as shown in Fig. 1. In the construction of Figs. 5 and 6, the combustion chamber liner 90 may be made of one piece open at its top. The heat exchanger includes a pair of castings 92, 94, each of which has internal ribs 90 and external ribs 98 formed integrally therewith. The castings are secured together by suitable bolts 99 and are conformed along their peripheries to provide one wall of, a passageway I00 of generally semicircular cross-section. A circular perforated band I02, which is suitably secured in position by clamping the castings 92 and 94 together, forms the otherwall of the passageway I00.

Within the chamber formed by the ring I02 is a vibration-damping structure comprising a pair of similar metal stampings I04, I05, which are secured together by having their inner and outer flanges welded together, these stampings thus forming an annular space, which is substantially filled with a suitable soundand vibration-damping filling I08. This filler may consist of a metallic wool; such as stainless'steel wool, or other suitable similar material, such as glass wool. The stampings I04, I05, are perforated to provide a large number of small ports providing restricted communication between the metallic wool filled space and the spaces between the fins 96.

As previously described, the heater is rendered operative by causing the flow of combustible mixture to the combustion chamber and igniting the 'mixture in this chamber by electrically energizing the igniter 68. The ignited mixture flows 7 from the combustion chamber through ports 9| formed in the ceramic liner 90 and from thence between the radial fins 96 and through the ports in the band I02 to the annular passageway I00. I The air is exhausted from the passageway I00 through a suitably connected exhaust pipe 40, which projects through and may be welded to the casting 94.

By virtue of the fact that the heat exchanger is made of simple perforatedstampings and .a pair ofcastings which include both internal and external fins, the parts may be easily and quickly assembled and the cost of manufacture thus reduced to a very moderate value.

The heater is very compact and by virtue of its shape may be utilized efiiciently in aircraft where space and weight limitations are frequently controlling.

While I have shown and described particular embodiments of my invention, it will be apparent to those skilled in the art, that numerous modifications and variations may be made therein without departing from the underlying principles of the invention. I therefore desire, by the following claims, to include within the scope of my invention all such modifications and variations by which substantially the results thereof may be obtained by the use of the same or substantially the same means.

'I claim: 1. A heater of the internal combustion type armors comprising, a central combustion chamber form-.

disc-like plates with external and internal sen erally radial fins formed integrally therewith,

means for securing said plates together, and

means held between the internal fins of said plates to form acoustic vibration damping means;

2. A heater of the internal combustion type comprising, a central combustion chamber forming means, a heat exchanger of generally flat disc-like shape surrounding said combustion chamber, said heat exchanger having a pair of disc-like plates with external and internal generally radial flns formed integrally therewith, means for securing said plates together, means held between the internal fins of said plates to form acoustic vibration damping means, and means for circulating air to be heated past said external fins.

3. A heater of the internal combustion typ comprising, a central combustion chamber forming means, a heat exchanger of generally flat disc-like shape surrounding said combustion chamber, said heat exchanger having a pair of disc-like plates with external and internal generally radial fins formed integrally therewith,

means for securing said plates together, means held between the internal fins of said plates to form an acoustic vibration damping means, said damping means comprising a pair of perforated annular members forming a space between them and a filler oil acoustic damping material within said space.

i. In a heating apparatus, the combination of means forming a combustion chamber, means for supplying a combustible mixture of a liquid loci and air to said combustion chamber, said means having ports opening into said combustion chamber near the bottom thereof, a heat exchanger of generally flat shape secured to said combustion chamber and surrounding a portion.

of the latter, said heat exchanger comprising a pair of plates secured together, having external fins and having a peripheral exhaust passageway, and a filler in at least a part of the space between said plates formed of a heat retaining material in a sufficiently finely divided state to act as an acoustic damping means to inhibit oscillatory combustion.

5. in a heater having means forming a generally vertical combustion chamber having an inlet opening in the bottom thereof, an annular hori rental heat exchanger surrounding the upper portion of the combustion chamber and having a compartment communicating therewith, an acoustic damping means occupying a substantial portion of the space within said compartment, means to supply a combustible mixture of fuel and air to said inlet opening, means to convey the products of combustion from said compartment. a casing spaced from and surrounding said heat exchanger, said casing having opposed axial inlet and outlet openings, and means causing flow of air to be heated into said casing through said inlet around said heat exchanger and from said outlet.

6. A heater of the internal ,combustion type comprising in combination means providing a w means for igniting the mixture in said chamber,

comprising two plates extending outwardly in vertically spaced relation to each other, the wall of the combustion chamber having a series of openings therethrough leading into said second chamber for the escape of thecombustion gases, acoustic vibration. damping means loosely filling the greater portion of said second chamber, and means in heat exchange relationship with said second chamber for leading air to be heated outwardly and upwardly and then inwardly along the walls of said second chamber. 1

'7. A heater of the internal combustion t comprising in combination, mean providing a combustion chamber, means for supplying a cornbustible mixture of fuel and air to said chamber,

means forming a second chamber about the upper portion of said combustion chamber and comprising two plates extending outwardly in verti-. cally spaced relation to each other, the wall of the combustion chamber having a series of openings therethrough leading into said second chamcombustion chamber, means for supplying a com bustible mixture of fuel and air to said chamber, means for igniting the mixture in said chamber, means forming a second chamber about the upper portion of said combustion chamber and and then inwardly along the walls of said secondchambe ber for the escape of the combustion gases, a perforated wall section in the form of a ring dividing on the inner portion of said second chamberfrom the outer portion thereof, acoustic vibration damping means loosely filling the inner portion.

of said second chamber-,an exhaust duct opening from the outerportion of said second chamber, and means comprising a heat exchanger for leading air to be heated outwardly and upwardly and then inwardly along the yvalls of said second chamben.

8. A heater of the internal combustion type comprising in combination means providing a combustion chamber, means for supplying a com bustible mixture oi fuel and air to said chamber, means for igniting the mixture in said chamber, means forming a second chamber about the upper portion oi said combustion chamber and comprising two plates extending outwardly in vertically spaced relation to each other, the wall of the combustion chamber having a series of openings therethrough leading into said second sham.

, her and constituting the only outlet from the combustion chamber for the escape of the comm bustion gases from the combustion chamber, acoustic vibration damping means loosely filling the greater portion of said second chamber, an exhaust duct communicating with said second 'chamber', and means in heat exchange relationship with said second chamber and comprising radially positioned fins for leading air to be heated outwardly and upwardly and then inwardly along the walls of said second chamber.

9. A heater of theinternal combustion type comprising in combination means providing a combustion chamber, means for supplying a combustible mixture of fuel and air-to said chamber,

means for igniting the mixture in said chamber,

means forming a second chamber about the upper portion of said combustion chamber and comprisingtwo plates extending outwardly in vertically spaced relation to each other, the wall of the combustion chamber having a series of openings therethrough leading into said second chamher for the escape of the combustion gases, acoustic vibration damping means filling a portion of said second chamber. and means in heat exchange relationship with said second chamber for leading air to be heated outwardly and upwardly HENRY J. DE N. MCCQILUM;

y 7 Certificate of Correction Patent No. 2,410,548. .November 5, 1946.

HENRY J. DE N. McCOLLUM, DECEASED It is hereby certified that the above numbered patent was erroneously issued to Thelma McOollum, Executrix of said Henry J. De N. McCollum, deceased whereas said patent should have been issued to Stewart-Warner Corporation, of Chicago,

Illinois, a corporatzon of Virginia, as assignee of the entire interest therein, as shown by the record of assignments in this Oifice; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this28th day of January, A. D. 1947.

LESLIE FRAZER.

First Assistant Gomnnisdoner of Patents.

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