US2808877A - Automatic heater for cockpits, auto bodies and the like - Google Patents

Description

w. l. E. KAMM 2,808,877

AUTOMATIC HEATER FOR COCKPITS, AUTO BObIES AND THE LIKE l Oct. 8, 1957 Filed Jan. 9, 1951 AUTOMATIC HEATER FOR COCKPITS, AUTO BODIES AND THE L Wunibald I. E. Kamm, Dayton, Ohio, assigner to the United States of America as represented by the Secretary of the Air Force Application January 9, 1951, Serial No. 205,161

9 Claims. (Cl. 158-81) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without payment to me of any royalty thereon.

This invention relates to an automatic combustion apparatus useful as a heater for cockpits, cabins, auto bodies and similar spaces.

Combustion heaters for automobiles are not new. The conventional type is operated in connection with the internal combustion motor of the vehicle using suction from the intake manifold. The operation of the motor is thereby often rendered uneven and weak. Other systems demand the use of compressed air, which involves the presence of tanks and compressors. Specifically, this invention is an improvement upon the system shown in the Alsberg Patent 1,337,498.

The present invention is superior to the conventional system in that, by the use of a self pressurizing boiler in connection with a fuel-pressure controlled needle jet, no outside sources of compressed air are necessary; one source of electric current provides all of the necessary initial energy. By the use of a special combustion primer and superheater, electrical energy may be dispensed with.

Among the objects of the invention are the provision of a system which in its preferred form may be started and stopped by a push button or similar electric switch.

Another object is to provide a system requiring only electric energy in addition to the manual control mentioned, to start operation of the apparatus.

Another object is to provide for automatic ignition, preheating, control, refueling and purging of air from the system.

ln the accompanying drawings:

Fig. l is a side elevation of the system, partly schematic and partly in section;

Fig. 2 is a longitudinal section of the needle type burner valve and its controls;

Figs. 3, 4 and 5 are schematic showing in section modified forms of the superheater; and

Fig. 6 is a corresponding view of another form of superheater which employs a porous liquid absorbent body in conjunction with an electrical ignition means. A match or striker means (not shown) may be substituted as an equivalent for electrical ignition.

In Fig. 1, 10 is a conventional fuel tank which contains a liquid fuel (not shown) which may be gasoline. From the bottom of the tank 10 extends a fuel delivery conduit 11 in which there is situated a pump 12 for delivery of fuel via conduit 9 to a vehicle carburetor (not shown). Also on the delivery side of the pump 12 is a conduit 11a which delivers fuel to a fuel boiler 14 and an auxiliary fuel tank 15. Situated in the conduit 11a is a check valve 8 to check any back presssure from the boiler 14 and therefore eliminate vapor lock. From the top of fuel tank 10, a return conduit 13 connects the tank 10 via the conduit 16a with the auxiliary tank 15. Situated in the conduit 13 is a pressure relief valve 27 of .a well known type which is used to purge the fuel system of any excess internal pressure. Valve 27 is merely lCC a throttling element, the opening of which can be regulated by hand. Its purpose is to limit the scavenging flow in purging line 13 thereby allowing liquid to pass more slowly, due to its density, than air. The auxiliary tank 15 is used to supply the boiler 14 with fuel for the main purpose of priming the system; the tank 15 is therefore filled at all times by fuel from the main tank 1t) via conduits 11, 11a and filler pipe 17. In the auxiliary tank 15, an overflow pipe 16 is used to return fuel to the tank 10 via conduits .16a and 13, thus making a closed fuel system. The fuel boiler 14 is generally cylindrical in shape and is provided with a spring-loaded inlet fuel valve generally indicated as at 18 and a similar type of outlet valve generally indicated as at 24. The valve 18 is located in the bottom portion of the boiler 14 while valve 24 is located in the top portion. Both valves are simultaneously actuable toward the interior of boiler 14, however, in different directions; valve elements 19 and 26 of the valves 18 and 24, respectively, are each connected by rod 21 to a bell crank 21a which is pivoted on a pin22 within the boiler 14. Coil springs 20 and 25 are provided to compress the valve elements 19 and 26 against their seats in the inlet valve 18 and outlet valve 24, respectively. Therefore the incoming fuel from conduit 11a, and the outlet to conduit 16a is controlled by valves 18 and 24, respectively. A conduit 7 extends,

from the bottom of the boiler 14 and is controlled by the valve 23 which serves as an emptying means for the boiler system. An outlet conduit 29 is connected at the top of the boiler 14 to supply fuel to the burner element generally indicated at 28. YSuperimposed between the boiler14 and the burner 28 is a superheater, generally indicated at 30 and comprises a cylindrical pipe construction 32 outwardly flared at the burner end andV about the pipe 32 the conduit 29 is wound as at 29a. Between the superheater 30 and the burner 28 and surrounding the conduit 29 is a heater or pressure generating heat coil 33 insulated from the conduit 29 and a jacket 34; jacket 34 envelopes the heating coil as an electric and thermal insulator. The conduit 29 is connected to the burner 28 as at 42, while a secondary fuel supply from the bottom of the boiler 14 is obtained by burner 28 through conduit 35 as at 42a. Thus a complete circuit of liquid vis provided between the boiler 14 and the burner 28, preparatory to lighting the burner, and during the building up of sufcient vfuel pressure.

The burner 28 is so arranged that its nozzle end will direct liquified fuel spray through the flared pipe 32 of the superheater 30 in a sufcient amount so that it can be ignited by the spark plug or ignitor 31. The burner 28, boiler 14 and superheater 30 are mounted Vwithin anl air induction llue 48. The circuit and burner will be hereinafter described.

Figure 2 is a more detailed and enlarged longitudinal sectional View of part 28 of Figure l. In Fig. 2, the burner element 28 comprises a long cylindrical body 39, provided at its forward end with a needle Valve seat 43 into which the needle Valve 38 is adapted to move to regulate the size of the orice. rounds the needle valve 38 in the body 39 and is in communication with the conduits 29 and 35 as at 42 and 42a, respectively. The rear part of the burner 28 is expanded'to form a bell 44, the outer end of which is threaded as at 45 to receive a cover 46. The inner side of the bell is threaded as at 45a to threadedly and adjustably engage the threaded flange members 54 and 54a'V which secure and position an expansible metal-type bellows 47 in the bell 44 to form one part of a sealing means between the bell 44 and the `needle valve 38. The other end of the bellows 47 is secured by solder to a'plate or washer 48 which in turn forms a part of the needle valve 38. On the external side of the lbellows 47 through'which` A central chamber 43a surthe needle valve 38 passes there is a washer 49, the purpose of which is to engage a pair of concentric coil springs, the inner of which is 50 and the outer of which is 51. One of the springs, namely 51, is made the stronger and is intended to come into play only after the-pressure has forced the needle valve 38 back and compressed the weaker spring 50. The spring 50 is so arranged as to be compressed between the washer 49 and an adjustable screw type member S6 threadedly mounted in the bell 44 as at 45a to adjust the tension of the spring 50 on the bellows 47. The larger and stronger spring 51 is so arranged that it also abuts the washer 49 while its other end does not quite bear against an adjustable bearing ring 52. The bearing vring 52 ispositioned from the be'llcap 46 by pins 46a, which ride the bottom of the cover plate 46 and pass through holes 56a in the adjustableftensioning member 56. It may be seen from the drawings that a rotating motion of the knob 53, the stem 53a, and tensioning member 56 will adjust the spring tension of spring 50 and *will also allow the spring bearing plate52 and pins 4621 to rotate with them, yet slide in the holes 56a. To adjust theV spring 51 Va rotary motion of the cap 46 will force the pins 46a, which. ride the bottom vside of the cap, to move in or ou't'of the holes 562z'and thereby limit the ymovement of the spring 51. lAt the rearward end of the uneedle `valve 38 is mounted `a push 'button 59 which can be operated by the operator o'f the vehicle lto close the needle valve 38 and thereby stop further operation of the heater. In order that therieedle 'valve 38 will 'not return Vto open position during theftifne the fuel is still under` pressure, -a lock stop 59iai`is used,assuring no further iopening of the needle valve 38 and'consequently no further heating of the boiler 14. It also be seen from Fig. 2 that a safety device toprevent overheatingk of the boiler such as a thermostatic control 55 may be attached to the boiler 14 and set'lat apredetermined temperature. Overheating of the boiler 14 therefore energizes the solenoid 57, causing the armature 58 yto engage lock stop 59a and halt the opera-V tion ofthe heating system. v

The electrical system comprises a manually operated switch 31a`(see Fig. 1) which, when closed, completes a circuit through the heating pressure generating coil 33, conduit 36a`and source Vof power, such as a battery 36, to heat the fuel in conduit 29. The vapor pressure so generated causes a backward movement of the needle valve 38 (see Fig 2)A and'arm 37a adjustably positioned on the needle valve 38 to make felectrical contact with aexible "arm 37b of'a sv'vitchunit 37, the movableicontact 37a being grounded. Closing of the switch 37 will fire'the sparkplug r'ignite'r 31 and thus ignite theVV fuel vapor whichisbeing'released'by the needle valve 38 of the burnerZS.

YIn Fig. 3 a form lo'fsuperheater 30is shown in which the flame from the Vburner Z8 is directed in the ared tube 32 about which is wound conduit 29a which delivers fuel from the boiler 14 to the burner 28.

Fig. 4`is a similar arrangement, except that the tube 32 is slotted at its middle portion as at 61. Flame passes through this portion, about which is wound the superhe'ater conduit 29a. Itis-spaced radially fromrthe slotted portion 61 but in Contact with those parts of the pipe 32 which areof normal diameter. y K

"In Fig. 5 the' arrangement is again similar to Figs. 3 and4 in that'the conduit 29a is wound around thepipe 32 except that itis 'contained in a housing or pan 62, which serves to'collect excess fuel. The pipe 32 is `interrupt'edfas nat 63 and the convolutions of the conduit 29a extend over the openingi63 which serves to facilitate' contact of the burner flame with the coils of the conduit 29a. .i v i p YIn. Fig. V6 na vdifferent arrangement is shown which .-is adapted'to serve as aprirner unit in which the use of the elct'r'iefhe'at pressure coil 33 is dispensed with. In this forin, thereis also aared tube 32 which is perforated` I closed by the knob 59, thus extinguishing theame.

as at 60 in this case and has below it a pan 64 containing a porous ceramic body 65, such as re brick. A delivery fuel conduit 66, which is perforated where it passes through the ceramic body 65 is so arranged to deliver fuel to the ceramic body 65 and an asbestos pad 67 which surrounds a spark plug or igniter 68. In this arrangement the superheater 69 is located immediately above the pan 65. The fuel passes through grid 71, which in this case is made of square tubing. The pipe 32 being in close Contact with the pan 64 and having perforations 60, allows the flame from the fuel in ceramic body 65 to enter the pipe 32 and thus ignite the fuel spray from the burner nozzle 39. in this device a flint striker mechanism, match or any other similar device can be used as a substitute for an electrical ignition -device 68 to make the primer entirely independent of electrical ignitionv devices.

Operation Assuming that the fuel tank 10, boiler 14 and auxiliary tank 1S are filled with fuel, the switch 13a is closed by the operator of the vehicle for a period of time only to facilitate the opening of the burner to its automatic position.

Upon the closing of switch 31a a circuit is made through the battery 36, conduit A36a and the pressure generating heat coil 33 to heat the fuel in conduit 29 to a vaporous condition. The pressure generated by the heating of the fuel causes the rearward motion of the lbellows element 47, needle valve 33, spring 5) and contact 37a, when the pressure of the vaporized fuel is sufticient enough to move the needle valve 38 to the open position, the arm 37a contacts the flexible arm 37b thus closing the circuit through switch V37 and firing the fuel vapor escaping from the orifice of the burner nozzle 39 by the igniter 31. The flame isconcentrated through the tube 32 of the superheater 3i) and heats the fuel in the conduit 29 and 29a. Thereafter, it is not necessary to use the pressure generating heat coil 33 and the switch 31a is opened; As the pressure builds up in the chamber 43a and against the bellows 47, the needle valve 38 moves still further open. Contact arm 37a makes contact with the flexible arm 37b and fires the vaporous fuel, as previously stated. The contact arm 37a then passes beyond the arm 37b, thus breaking the tiring circuit of the igniter 31. To close down the system, the operator pushes the knob-59 on the needle valve 38 inwardly, thus overcoming the pressure in the burnerZS. The contact rarrn37t will tend to retire the circuit on its return past the arm 37b, so the contact 37a is insulated as at,37c.

-The flame from the burner 28 is concentrated on Ythe boiler 14 and in turn heats the air induction flue 40, which in turn heats the -area to be heated. Flue 40 may have any "practical form and size which serves the purposeof conducting the air which must be heated and to envelope the hot parts of the heater. has the form of a cylindrical tube. Heat on the boiler 14 causes the fuel therein to become vaporized and the pressure within the boiler thereupon closes the inlet Valve,

1S and the outlet valve 24 simultaneously. These valves will remain closed until the fuel within the boiler 14 is exhausted or the needle valve 380i the burner 28 is As the pressureV within the boiler 14 drops below the head pressure of the auxiliary tank 15 orof the incoming fuel being pumped from the main fuel tank 10, theA valves 18 and 24 will open, thus allowing the boiler 14 to be replenished and then againrthe system will bey ready to function. n

l The operation and cooperation of valve means 18 ,and 24 Vfor pumping air from the boiler'is more easily understandable withthe following elaboration. As soon ,as the` innervpressure of the boiler drops down under that value which'is sucient vwith the force of springs 20 and 25 to-hold valves 19 and26 closedagainstthe staticpressure in conduit 11a, both valves open. :,Under-1said static As illustrated, it Y pressure existing in line 11a, the boiler fills itself throu'gh valve 19 with fuel, emptying its gas or air residual content through valve 26 into the purging line 13. With static pressure approximating balance in lines 11a and 13, both valves close again, alittle earlier however than the time at which balance is reached, due to the force of the springs. The purpose of auxiliary tank 15 is to ll the boiler if pump 12 is out of operation. Tank 15 has sufficient capacity to fill boiler 14 one or more times. At is the main fuel tank of the powerplant or vehicle in which the heater is installed and is assumed to contain fuel at all times. If pump 12, which is the main pump for providing fuel for the engine of the powerplant or vehicle, is in operation, it lls the boiler 14 through line 11a. If the valves 19 and 26 are open, as described above,

the pump 12 fills tank 15 to the elevated level of pipe 16 or to the level controlled by a floating body valve (not shown in Figure l). The heater can operate without being connected to tank 10, if tank 15 is large enough to deliver as many fillings of boiler 14 as wanted.

The purpose of priming the system is to generate initial heat that pressurizes ducts 29, 35 and boiler 14, to a high enough degree to open the needle valve 38. Then the developed heat increases and with it the pressure and the stroke of the needle until the maximum heat output of the heater is attained. It is a feature of this invention that the pressure head of tank 15 or the pressure of pump 12 is suicient to overcome the bias of springs 20 and 25. The springs should be dimensioned within these limits to be strong enough on one hand to close the valves against friction and against a pressure differential in line 11a over line 16a when the boiler 14 is filled. They should be soft enough, on the other hand, to yield to the hydraulic4 pressure in the line 11a when the boiler contains little `or no fuel and the pressure of the air or gas is reduced because of being cooled down.

The form of superheater shown in Fig. 3 is preferred for lighter hydrocarbons such as when gasoline is used, ysince it does not have the tendency to overheat these fuels.

The form shown in Fig. 4 is preferred for use when the heavier hydrocarbons are used since it transfers heat more intensively.

The form shown in Fig. 5 is preferred for use in vehicular installations in which spillage of fuel in the vehicle must be avoided. The pan 62 retains any spilled fuel until same is volatilized by the continued operation of the burner.

Fig. 6 shows a form of primer and superheater which is preferred when it is desired to start the heater without any electrical assistance for preheating. This form of superheater is preferably started with an auxiliary supply of gasoline ignited by a match and could be by energizing the spark gap 68'. After the grid 71 becomes hot enough for the operation of the burner, the fuel feeds through pipe 29 and is sufficient even to heat the heavier fuel. Since it is common practice to start a burner on the light fuel and switch to a heavier fuel after pre-heating, and the Valve apparatus switching is well known, no details of the switch-over installation are shown.

It is to be understood that combustion experts in possession of this disclosure will be able to make changes to suit various operating conditions and various sizes of apparatus without departing from the spirit of the invention as set forth in the accompanying claims.

'e What I claim is:

l. In a space heating apparatus a fuel tank, a fuel boiler, means for effecting the transfer of fuel from said fuel tank to said boiler, a rst valve means for injecting fuel into said boiler, a second valve means for purging air from said boiler, means connecting said first and second valve means positioned within said boiler for opening the second valve means when the first valve means is opened on decrease of pressure in said boiler and for closing both valve means substantially simultaneously on increase thereof, fuel burner means connected to` said boiler for fuel'transfer therebetween on rise of pressure in said boiler, superheating means in said connecting means, fuel pressure generating means operatively associated with said connecting means for starting delivery of fuel to the fuel burner means and said fuel burner means having means automatically responsive Y to a predetermined fuel pressure to ignite the fuel therein.

2. In a space heating apparatus a fuel tank, a fuel boiler, pump means Yfor transferring fuel from said fuel tank to said boiler, a first yieldable valve means in said boiler.

for the admission of fuel, a second valve means in said boiler for purging air from said boiler upon the entrance of fuel through said first valve means, a bell crank.

positioned Within said boiler and interconnecting said rst and secondV valve means and arranged for opening the second valve means upon the opening of the firstY valve means on decrease of pressure in said boiler and.

closing both valve means substantially simultaneously on increase thereof, fuel burner means, fuel transfer means connecting said boiler and said fuel burner means, the fuel burner means including ignition means automatically energized on the imposition of a predetermined fuelpressure in said fuel burner means on delivery of fuel thereto,

superheating means in said fuel transfer means placed suby stantially in the path of the flame from the burner.

3. In a space heating apparatus a fuel tank, a fuel boiler, means for transferring fuel of said fuel tank to said boiler, fuel burner means, fuel transfer means connecting said fuel boiler and fuel Vburner means including i an intermediate coiled section constituting a superheating section, said fuel burner means having a combustion chamber and including a needle valve having a stem, resilient means connected to said stem responsive topressure from the incoming fuel from the fuel transfer means to open the needle valve and deliver fuel to the? means and said fuel boiler to deliver fuel to said boiler,

a valve means, means connecting said boiler and said valve means to deliver fuel from said boiler to said valve means, a burner housing, said valve means being responsive to a predetermined pressure in the delivery of fluid from said boiler to meter fuel'to said burner housing, means operatively connected to said valve means automatically operable on the delivery of fuel by said valvemeans to said burner housing to ignite the fuel therein to heat the surrounding air, said means connecting said valve means and said boiler being conducted around said burner housing to superheat the fuel delivered to said valve means to effect a greater utilization of the fuel.

5. A heating system comprising a boiler means, fuel supply means connected to said boiler means, auxiliary fuel supply means connected to said boiler operative to insure fuel delivery thereto, valve means in said boiler for admitting fuel thereto and purging air therefrom simultaneously, burner valve means, delivery means from said boiler to said burner valve means, an initiating means in said delivery means to heat the fuel therein to initiate delivery thereof to said valve means, a combustion chamber connected with said burner valve means, said burner valve means being responsive to initial delivery of fuel thereto to deliver fuel to said combustion chamber, ig-

nition means connected between said burner valve meansV and deliver heat to the space to be heated.

'6. A heating systemvscomprising a boiler unit,1a valve unit and a4 superheater nnit,.mean`s connectedwith-said boiler unit to supply fuel thereto, auxiliary fsupplyxmeans connected to vsaid supply `means and said boiler'irnitto insure delivery of fuelA to said boiler unit, deliver-ymeans connecting fsaid boiler-unit. and said .valve unit including afcoilportion constituting an elementfoffsaid superheater unit, Va icombustionchamber lat theoutlet Yof said valve unit extendingthrough saidcoil unitv to formfanotherpa-rt of the superheater unit, and ignition means in said combustion chamber automatically energized on delivery of fuel thereto Awhereby continuous deliveryof fuel supply may be maintained to said valve unitzford'eliveryto said combustionA chamber for ignition; therein and 'superheating ofthe Afuel in the Vcoil beingldeliveredto the valve unit, and said boiler vunit 'being in the path fof heat discharged from said combustion chamber to cause heating of the fueltherein for eectingdelivery thereof to the valve unit asrheat is dischargedoncombustion to the vspace to be heated.

7. A heating. system `comprising a boiler unit,a `valve unit anda burner unit, said valve unitopening into said burnerunit, vand saidboilerunit being in the `path of the heat from said burner unit, means providing a continuoussupply of' fuel to `said'boiler unit, delivery means connecting'said boiler unit and `said valve unit and having aportionthereof adjacent said burner unit to superheat the fuel in said delivery means, a needle valve normally closing the `opening in said valve unit to Vsaid vburner unit and responsive to the delivery of superheated fuel to said valve unit to open said 'needle valve, and means connected to said needle valve and operatively associated therewith in said burner unit, operable on the opening of said needle valveto ignite the fuel delivered to said burner whereby to deliver heat to superheat the fuel fin the delivery means, raise the temperature of the fuel iin 'the boiler and deliver heat to the space 'to be heated.

8. Ak heating system comprising a boiler unit, fuel supply means connected to said boiler unit to provide a continuous supply of fuel thereto, means in said boiler unit to simultaneously admit fuel thereto and purge air therefrom, a valve unit, fuel delivery means connecting said boiler unit and said valve unit to deliver fuel to said valve unit on rise of pressure within the boiler unit, a combustion chamber arranged in juxtaposition to said fuel delivery means at a portion thereof to raise the temperature of the fuel therein, Vsaid combustion chamber being arranged to direct heat therefrom to 4the boiler unit to heat the boiler unit, said combustion chamber being directly associated with said valve unit to receive 8 fuel'there'from, anignition'means i`n said combustion chamber operatively connected to said valve unit, said ignition means being-energized@ a ydelivery 'of iel'to said combustion Chamber whereby the 'fuel is ignited'to heat' thefuel 'in the fuel delivery means, heat the boiler unit, and supply 'heat to the space tobe heated.

9. In an oilburningfsys'tem, a main fuel tank, a fuel boiler, means for delivering oil from said tank 'to v'said fuel boiler, .means within said boiler responsive to 'a decrease of pressure therein adapted to simultaneously admit a change of fuel therein and purge saidboiler, an oil burner assembly including a valve unit and a combustion chamber, two oil delivery pipes connecting said boiler and said burner assembly, the iirst connecting the top of said lhoiler and the top Vof said burner, the second connecting the bottom of said boiler and the lower'pa'rt of said burner, superheater means in 'at leastone of "said References Cited in the file of this patent UNT-TED STATES PATENTS 533,593 House Feb. 5, 1895 583,510 Rider, June '1, 1897 954,380 Davis Apr. 5, 1910 968,233 Best Aug. 23, 1910 l1,337,498 Alsberg Apr. 20, Y1920 1,391,385 Jacobsen Sept. 20, 1921 1,494,649 VTrask May 20, 1924 1,529,187 Keiihonz Mar. 10, 1925 1,602,950 Seifert Oct. l2, 1926 1,687,328 DElia ocr. 9, 192s 1,696,389 Debaecker Dec. 25, 192s 1,813,612 DuPent July 7, 1931 2,038,264 Bowman er a1 Apr. 21, 1936 2,347,842 Rayeld May 2, 1944 2,393,792 McCollum `lan. 29, 1946 2,460,451 Farrell Feb. 1, 1949 2,492,756 McCollum Dec. 27, 1949 2,603,278 Husband July 15, 1952 FOREIGN PATENTS Great Britain Oct. 17, 1930

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