US2439748A

US2439748A - Heat engine

Info

Publication number: US2439748A
Application number: US548290A
Authority: US
Inventors: Nettel Frederick
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-08-05
Filing date: 1944-08-05
Publication date: 1948-04-13
Anticipated expiration: 1965-04-13

Description

April 13, 1948. F. NETTEL 2,439,748

I HEAT ENGINE Filed Aug. 5, 1944 2 Sheets-sheet 1 ExHnusT IN VEN TOR.

April 13, 1948. F. NETTEL 2,439,743

HEAT ENGINE Filed Aug. 5, 1944 2 Sheets-Sheet eV WWI-H I} a Q VMORIZER.

IN VEN TOR.

Patented Apr. 13, 1948 UNITED STATES PATENT OFFICE HEAT ENGINE Frederick Nettel, Manhasset, N. Y.

Application August 5, 1944, Serial No. 548,290 18 Claims. (01. 123-179) This invention deals with methods and means for fueling for starting and operating at low loads of internal combustion engines fed with solid hydrocarbons.

Hydrocarbons, solid at ordinary ambient temperatures, have been proposed as fuel for internal combustion engines by the applicant. Reference is made to his Patents Nos. 2,396,524 and 2,420,- 325, and his co-pending application Serial No. 505,053, filed October 5, 1943, now abandoned, where means for fueling such engines have been disclosed.

Since all hydrocarbons which are solid at ambient temperatures, are essentially high-boiling fuels, difficulties arise in starting such engines from cold condition. These difilculties can be overcome by using for starting auxiliary low-boiling fuels, for example gasoline. This solution is, however, inconvenient in many cases because it necessitates separate storage and feeding facilities for two different fuels. Besides, using lowboiling fuels generally involves fire hazard, thus partly nullifying a valuable asset of solid highboiling fuels.

It is known in engines using high-boiling liquid fuels such as kerosene, liquefied naphthalene and the like, to combine exhaust gas heated vaporizers with independent heating burners or lamps which supply a more or less constant amount of heat to compensate for the variable heat supplied by the exhaust gases.

These devices did not find acceptance in practice because kerosene or heavier oils are very complex mixtures of hydrocarbons with different boiling points. In heated vaporizers their lowboiling components vaporize first. Very soon a residue of heavy oil, tar and asphalt accumulates in the vaporizer, covering the heat transfer surface, making continuous operation impossible. The known use of liquefied naphthalene and similar ordinarily solid hydrocarbons demands large quantities of heat for melting these fuels in tanks and pipes prior to starting. This requires much time and is inconvenient for many purposes, especially in vehicles of every kind.

These defects are eliminated by the present invention which permits quick starting and operating at any desired load of engines using no other than high boiling solid fuels.

It is the basic object of this invention to provide means for cold-starting of engines fueled with hydrocarbons, solid at ambient temperatures, but which liquefy and subsequently evaporate substantially without residue, when heated.

It is another object of this invention to provide means to satisfactorily liquefy and evaporate said solid fuels prior to their combustion in the engine cylinder during low load operation or idling of the engine.

It is a further specific object of this invention to utilize the means for attaining said first two objects for providing hot gases or air for uses external to the engine. For this reason the fuel will be referred to in the claims as particulate.

The detailed nature of these objects, and of further more detailed objects of this invention, together with the manner in which the several objects are attained, will appear more clearly in the ensuing description of the apparatus illustrated in the accompanying drawings by way of non-limiting examples, these drawings forming part of this specification in which Fig. 1 shows an example in which combustion products from an external combustion are used for preheating the engine vaporizer internally and externally.

Fig. 2 shows a modification of the vaporizer for the arrangement as per Fig. 1 for heating the vaporizer from outside only.

Fig. 3 shows an alternativ arrangement with common fuel feeder for both, the engine and the external combustion chamber, and provision for heating the intake air during starting; also for heating the engine lubricating oil, the crankcase and the engine exterior.

Fig. 4 represents a modified arrangement with special vaporizer design, heating jacket for the engine intake air, means for preheating the engine spark plug, and control means for the engine.

Fig. 5 is a detail drawing of the spark plug for Fig. 4.

Fig. 6 shows an arrangement according to this invention applied to a supercharged engine.

The basic object of this invention is achieved by using for normal operation of engines fueled with the specified solid hydrocarbons in commlnuted form exhaust gas heated Vaporizers or boilers of the general type described in my above mentioned co-pending applications, and by providing heat for starting, low-load or no-load (idling) operation by an independent heating burner disposed in a combustion chamber external to the engine cylinder, this burner being fueled with the same or similar solid hydrocarbons in commlnuted form, and of a general type similar to those used for other commlnuted (pulverized) fuels such as coal, coke, saw dust etc.

Experiments by the applicant have shown that the specified commlnuted hydrocarbons can be ignited by melting and evaporating a very small quantity, and by exposing the mixture of their vapors with air to any kind of hot flame, for example an electric spark. As soon as a small flame (pilot flame) is created, which takes only a few seconds, comminuted solid fuel of the specified kind can be fed into said combustion chamber, together with a suitable air quantity, and a practically smokeless hot flame of any desired intensity can quickly be built up and maintained. Contrary to experience with other pulverized fuels, the degree of comminution is of only secondary importance in this case. Even relatively coarse particles, such as for example commercial naphthalene chips, can be burned efllciently in the manner described.

The heat from this burner can according to this invention be utilized for preheating the fuel vaporizer and the engine either directly or indirectly. Experiments have shown, however, that the combustion gases from the burner may contain traces of unburned hydrocarbons in vapor stage. These impurities, when introduced into a cold cylinder, may solidify on the walls and particularly on the spark plugs, making these unflt to work properly. Such disadvantages do not exist for preheating the vaporizer, which therefore can be heated either by leading the combustion gases through it, or by surface heat transfer from these gases.

Preferably air is heated in a tube coil within or in a heating jacket surrounding said external combustion chamber. Such tube or jacket is connected to the engine intake manifold, so that the engine, when cranked, sucks hot air into the cylinder, ejecting it thereafter to the atmosphere. thus preheating the engine most effectively from inside. For preheating of the vaporizer the hot gases from the external combustion are preferably led along its outer surface.

Experiments by applicant have shown that for starting of an engine from cold state it may not be necessary to preheat the cylinder if, according to this invention, an ignitable mixture of fuel vapors and air is produced in the hot vaporizer in which mixture the fuel vapors exist preferably as superheated vapors, or in other words the mixture is at a temperature substantially above its dew point. Such superheated hydrocarbon vapors have been found to be very stable so that when they come into contact with the cold walls of the cylinder and the piston, condensation and/or sublimation is substantially reduced. The mixture remains in ignitable condition and reliable starting is assured.

Preheating of the intake manifold and cylinder may be preferably resorted to when the time required for starting the cold engine is not important or in case of low temperatures of these parts (in winter or under arctic conditions) After the vaporizer, and if desired those engine parts normally in contact with fuel, are thus preheated, solid fuel is fed into the vaporizer Where it melts and vaporizes within a few seconds in the presence of air, and is sucked by the cranked engine through the vapor tube into the cylinder. hot fuel vapors and hot air produced in the vaporizer can be in proper ratio already in the vaporizer or in the intake manifold. The combustible mixture ignites in the cylinder and starts the engine. 7

Experiments by applicant have shown that the vaporizer, due to its small mass, heats up faster than the cylinder block. Even after the vaporizer is hot enough to properly vaporize the solid fuel,

sesame the exhaust gases leaving the still rather cool cylinder (especially in the case of liquid cooled engines) may not yet be hot enough to supply the necessary heat for the proper sustained functioning of said vaporizer. Under such circumstances it is advisable to continue operation of the burner. after the engine has startedfor some time, until a sufflcient positive temperature differential exists between exhaust gases and vaporizer.

Generally the temperature of the engine exhaust falls rather rapidly with load and/or speed, and a condition arises where at partial load, or even more so at no-load operation (idling), the above mentioned temperature differential is much reduced or disappears altogether. Under such conditions, according to this invention, the burner is started and takes over partly or fully the heat supply to the vaporizer. Obviously the fuel consumption is of minor importance under such temporary conditions.

As mentioned before, a smokeless flame can be maintained in the burner chamber very soon after its start, so that the flue gases may also be used for heating the engine exterior prior to starting, a practice for which separate air heaters are employed at present for air cooled aircraft engines.

It is within the scope of this invention to utilize the heat from the external combustion to preheat the coolant in liquid cooled engines prior to starting them, and said heat may also be used, with the engine at standstill or while running,

to heat air or liquids for uses external to the engine proper.

In very cold weather the lubrication oil'viscosity increases sharply. This leads to the practice of diluting the oil with gasoline. The present invention avoids this necessity by leading hot combustion gases through a heating coil disposed in the oil sump. In case hot air is produced by the starting burner it is, of course, also possible to lead a portion of said hot air into the. crank case to heat the oil as well as the crankshaft, bearings, piston rods and lower side of the piston. It will be seen from above that the burner can be used to keep the engine warm internally as well as externally in any kind of weather and for any length of time without the necessity of periodically starting the engine for that pu pose, as is the present practice for aircraft engines in alert condition.

It is within the scope of this invention to combine any and all of the above indicated means for utilizing the heat from the external combustion, it being however essential that the fuel is burned externally in substantially comminuted form without melting of substantial quantities of said fuel in coalescent form.

The fuel supply for the external combustion can be either independent of the fuel supply to the vaporizer or it can be combined with the latter. The choice between the two methods will depend primarily on the working conditions of the engine. In case the same fuel feeding device is employed for both starting and operation, the object of this invention is achieved by branching off a portion of the comminuted fuel prior to entrance into the vaporizer, burning it externally to the engine in an air stream, and transmitting heat from said latter combustion to the remainder of the fuel fed into the vapor-' izer, so as to supply partly or wholly the heat necessary for melting and evaporating of the fuel in said vaporizer. For many purposes independent fuel feeding devices for burner and cooled, in-line or radial, and it is also immaterial what type of fuel metering device or devices are employed for the engine and/or the auxiliary burner.

Referring now to the appended drawings:

In Fig. 1, I denotes the engine with cranking device II which may be of any known type, l2

the air intake pipe, l3 the exhaust gas pipe, H the spark plug, and IS the main air throttle. I6 is a vaporizer chamber with valve II at the bottom, la a jacket surrounding the vaporizer and normally connected to the exhaust pipe l3,

and Is an exhaust pipe from It to the atmosphere. 20 is a tank for comminuted hydrocarbon fuel, at the bottom of which is disposed fuel metering cell-wheel 2| driven by motor 22. The cell-wheel rides on a'stationar'y tube 23 which is open along the bottom. Tank and cell wheel housing forming part of it are connected by pipe 24 to the vaporizer interior. The vaporizer is connected by vapor tube 25 to air intake pipe l2. Auxiliary combustion chamber 26 communicates with exhaust pipe l3. The narrow bottom part of said chamber is equipped with an electric heater 21 anda spark plug 28 and represents the external ignition chamber 26'. Air blower 29, driven by motor 30 discharges into chamber 26 through pipe 3|. The end of this pipe within chamber 26 carries a burner head 32. Gate valves 33 and 34 allow to regulate or interrupt the air flow through pipe 3|.

20' is an auxiliary tank for comminuted hydrocarbon fuel for starting and low load operation: the parts 2|, 22', 23' and 24' correspond to and are essentially to the same design as the parts 2| to 24. Pipe 24' is connected to pipe 3|. Air pipes 35 and 36 with valves 35' and 36' lead from the pressure side of blower 29 to the stationary pipes 23 and 23' respectively inside the cell wheels 2| and 2|. 31 is a starting and bypass flap valve allowing with flap horizontal the gases to flow to the atmosphere at 38, or with flap vertical through jacket I8 and out at Is.

For starting of the engine from cold state the arrangement is operated as follows:

Heater 21 and spark plug 28 are switched on. The bottom of pilot flame chamber 26' heats up very quickly. Valve 33 is partly and valve 34 is fully opened. Flap valve 31 is disposed in horizontal position. Blower motor 30 is started, valve 35 opened, and motor 22' is started. Fuel now flows from tank 20' into pipe 3|, this flow being assisted by the air stream from pipe 35. The fuel particles reaching pipe 3| are immediately swept by the blower air into chamber 26 and reach the bottom plate of 26' where they vaporize practically instantaneously. The vapors mix with the air and are ignited by spark plug 28, forming a pilot flame into which now more fuel can be fed, making the flame self-supporting. Heater and plug can now be switched off. Hot combustion gases begin to flow from chamber 26 into jacket is surrounding the vaporizer I6 and out to atmosphere at it. when valve I! is opened. a portion of the gases enters the vaporizer interiorand flows through vapor tube 25 on the way out to atmosphere throt tle- It. The gases thus heat vaporizer l6 and vapor tube very quickly and effectively, so

that valve H can be closed, valve 36 opened and motor 22 started. Cell-wheel 2| begins to feed fuel into the hot vaporizer, being facilitated by the air from pipe 36 entering the slotted pipe 23 and causing an air stream in the direction of pipe 24. The solid fuel particles evaporate immediately in contact with the hot inner surface of the vaporizer. Now engine ignition is switched on andthe engine is cranked by starter motor The engine, acting as a pump, sucks very hot vapors and air from the vaporizer, and if necessary additional air through main throttle l5, into t e engine cylinder where the fuel-air mixture i tes and startes the engine, so that motor H can be switched off. Flap of valve 31 is moved into vertical position, motor 22' is stopped, and valves 33 and 34 are closed. The exhaust gases from the engine now flow via pipe l3 through jacket Ill and out at l9, supplying on the way heat to the vaporizer to keep it working properly.

It is possible with this arrangement to adopt a somewhat different procedure if desired: After the vaporizer is hot, the engine is cranked for some time with valve I! open and main throttle I5 closed. It is evident that in this case the combustion gases flow first through the vaporizer, then via vapor tube 25, intake pipe |2 into the cylinder and out at 38. This second procedure which ensures also preheating of the cylinder is preferable under certain conditions.

Fig. 2 shows a modification of the vaporizer suitable for use with the general set up as per Fig. 1. There is no valve at the bottom of the vaporizer chamber. When this vaporizer is used the starting procedure is modified so that while the vaporizer is being preheated by gases flowing through jacket i8, air is blown into the vaporizerinterior through pipe 38 and the cell-wheel 2|, with the latter at standstill. Said air is heated within the vaporizer by contact with the hot walls, and flows out through vapor tube 25 as described for Fig. 1. The vaporizer is thus heated by gases, acting during starting as air preheater. When cranking the engine the preheated air is sucked through the engine, heating the valves and cylinder from inside. Combustion products do not enter the cylinder which is advantageous for reasons explained before.

In Fig. 3 the parts corresponding to same or similar ones in Fig. l are denoted by the same numbers, Additional parts are as follows: Be-

tween cell-wheel 2| and vaporizer chamber It a flap valve 40 is disposed, which with flap in the extreme left position (indicated by dotted line) closes pipe 24 towards the vaporizer and opens the path for the solid fuel into branch pipe 4| connected to pipe 3|. With flap in vertical position the path to the vaporizer is open and entrance to 4| closed. In intermediate positions, as shown in full line, a portion ofthe fuel can enter the vaporizer while the remainder can enter pipe 4!. The auxiliary combustion chamber 26 is in this case arranged immediately below the vaporizer chamber, and is equipped with air heating coil 42 branched off from the pressure side of blower 29. Froin this coil three

branch pipes

43, 44 and 45 with valves 43', 44',

45' lead to the air intake pipe l2, into theoil sump of the engine and to an external heat consumer respectively. Flap valve 46, with flap in horizontal position connects pipe I 3 and II dl rectly to the space ll surrounding the vaporizer; in vertical position pipe I3 is connected to the atmosphere at 36', while pipe I! is brought into communication with pipe 41 leading to a. hood 48 above the engine. Exhaust pipe I! is equipped with throttle flap It.

For starting of the flame in 26, heater 21. plug 26, blower 29 function in the same way as described for Fig. 1. Flap 46 is in vertical position; and flap 40 is in dotted position to the left. Valve 36' is open. Motor 22 is started, which causes celiwheel 2| to discharge fuel into branch pipe 4| and thence into pipe ii. The fuel ignites after being swept into auxiliary ignition chamber 26'. Thottle flap I9 is partly closed. This causes the hot gases from 26 to flow partly through jacket I! and out at I9, while the remainder flows back through pipe l3, as indicated by arrow, thereafter through valve 46 into pipe 41 and hood 48, discharging along the outer surface of the engine cylinder, heating it from outside. Part of the heat produced in 26 is used for heating air blown by blower through coil 42. The vaporizer is heated as described for Fig. 2. When the engine cranking begins valve 43' is opened which causes very hot air from coil 42 to flow into the engine intake pipe l2 and thence through the engine cylinder. This air together with that from the vaporizer heats valves and cylinder interior very quickly. At the same time, or better even before cranking, valve 44' is opened allowing hot air to flow through pipe 44 heating the engine lubricating oil and discharging into the engine crankcase so as to preheat the lower part of the cylinder, piston as well as bearings. Through pipe 45 hot air can be supplied to any consumer outside the engine proper, for example the interior of a vehicle etc. This can be done even with the engine at standstill as long as a flame is maintained in chamber 25 which offers no difficulty since the intensity of that flame can easily be regulated within wide limits by adjusting the fuel and air quantities admitted to said chamber. As soon as vaporizer and engine are sumciently preheated flap I9 is opened, and flap 46 is moved into vertical position, cutting of! fuel to 25 and causing fuel to enter the vaporizer and vapors to flow via 25 to the engine intake l2 where they mix with additional air entering through throttle II, to form an lgnitable mixture which after entering the cylinder ignites therein and starts the engine. Now valves 32 and 34 are closed, flap of valve 46 moved into horizontal position, shutting of! pipe 41 and connecting pipe i3 with pipe l3, thus opening a path for the exhaust gases from the engine to flow into space l8 and out at l9, heating on the way vaporizer l8. Flame in 26 was extinguished when flap cut oif its fuel supply, At low loads flap 40 is in a middle position, as shown in full line, feeding fuel simultaneously to the vaporizer and to chamber 26, allowing a flame to be maintained therein to support the heating of the vaporizer by engine exhaust gases.

It is obvious to use separate fuel feed devices as described for Fig. 1, for Fig. 3. In the latter case it is sometimes advantageous to use a cheaper solid hydrocarbon as fuel for chamber 26, because anti-knock properties are not required for efllcient combustion in said chamber.

Fig. 4 represents another example of the invention showing a modified design for the vaporizer it which is equipped with heating tubes l6 arranged round the interior circumference through which the exhaust gases from the engine normally enter at the bottom and discharge at the top into jacket space l8. Exhaust gas pipe I3 is connected to the bottom of the vaporizer in communication with said heating tubes. It can be seen that the streams of engine exhaust and gases from 26 are kept separate and meet only in the upper part of jacket space It. During idling or low load operation of the engine it may be desired to keep the flame in 26 in operation. A damper ring l8 disposed in the upper part of Jacket l8 serves to reduce mutual disturbance of said both gas streams. Air heating prior to starting and during low load operation takes place in an air jacket 50 surrounding chamber 26. Air is taken in at 5|, flows through Jacket 50 into intake pipe l2 via main throttle i5 and to the engine cylinder.

Experiments by the applicant have shown that proper ignition of the fuel vapor-air mixture entering cold cylinders is facilitated if the spark plugs are preheated to a temperature substantially above the melting temperature of the fuel used. This preheating prevents fouling of spark plugs due to sublimation of fuel on the electrodes. According to thi invention plug preheating is effected by an electric resistance heating coil disposed round the plug body. Fig. 5 shows such a heated plug it with heating coil l4" embedded in insulation material, for example insulation cement. All electric devices are connected to a service battery 55, or other available source of energy, via switches a, b, c, d and e.

In order to ensure proper fuel-air ratio, motor 22 is provided with rheostat 53, connected by rod 54 with main throttle l5 and lever 52. When throttle I5 is moved for larger opening by lever 52, the rheostat is operated to speed up motor 22. Since the fuel quantity supplied by the cell-wheel metering device 2| is substantially proportional to the speed of said wheel, more fuel enters the vaporizer to suit the increased air quantity. The reverse action takes place if the throttle is closed. Turnbuckle 54' allows to vary the length of rod 54. By coordinating other cell-wheel speeds to a certain throttle opening the fuel-air ratio is adjusted.

Starting takes place as follows: Switch b is closed to start heater 21; and spark plug 28 is operated. Valves 33 and 34 are opened. Blower 30 is switched on by switch e. Fuel reaches the auxiliary ignition chamber 26' and starts the flame. Switch b is returned to ofi position. The combustion in 26 continues. Valve 46 is disposed with its flap in vertical position. The gases flow through jacket i8 and out at Hi. In the upper part of jacket l8 above damper ring la a slight pressure builds up which causes a portion of the gases from 26 to flow into the heater tubes I6 downwards into pipe l3 and out at valve 46. The vaporizer is in this case not only heated through its outer surface but also through said heater tubes, which accelerates heating considerably. The air entering the vaporizer via pipe 36 is also heated and flows through tube 25 and back through throttle l5, pipe l2, the heater jacket and out at 5|. As soon as the vaporizer and vapor tube are hot, the engine is cranked (cranking device not shown in this figure) Throttle I5 is opened so that air is now entering at 5|, being sucked through jacket 50, where it is strongly heated, then through pipe l2 into the engine and out at valve 46. Some time before cranking switch a is closed, causing spark plug H to heat up quickly. Very soon also the engine cylinder and valves are well preheated so that switch is closed causing motor 22 driving cell-wheel 2| to feed fuel into the vaporizer. The vapors generated in I6, mixed with a small quantity of air, flow through 25 into l2 where they meet additional hot air coming from 50, to form an ignitable mixture, which is sucked into the engine cylinder where it is ignited by plug l4 and starts the engine. d is switched oil, and valve 34 closed. This terminates combustion in 26. Valve flap #6 is moved into horizontal position, causing the engine exhaust to flow through heater tubes l8 and maintaining the vaporizer at a temperature sufficient 4 for proper operation. Switch a is disconnected to terminate plug heating. Valve 33 is closed to isolate the starting cell-wheel feeder from blower pressure. Plug 28 can be put out of action any time after the flame in 26 has become steady. At high loads the vaporizer temperature may become too hot for good performance. In this case valve 46 can be used as bypass valve by moving its flap into the inclined position, indicated by single dotted line. As can be seen, part of the engine exhaust can escape through that valve to the atmosphere. During normal operation of the engine, heating of the intake air in jacket 50 will be negligible since there is no combustion in chamber 26.

Fig. 6 is another example of the present invention showing application to an engine with gear driven supercharger. Vaporizer with fuel metering feeder, auxiliary combustion chamber are the same as for Fig. 4. The fuel feeding device with blower, to be connected to pipe 3|, are also the same as in Fig. 4, but omitted here. New parts are as follows: Supercharger 60 driven from engine shaft, Venturi nozzle SI for measuring the air quantity flowing through pipe [2. 63 is an air quantity (weight) controller, as known in the art, connected to nozzle 6! by impulse tubes 62. 65 is an exhauster connected to pipe i2.

The operation of the arrangement both for starting and for load operation is the same as for Fig. 4. If the engine is used at greatly varying air densities it is necessary to maintain fuel-air ratio control by appropriate means. Such are the nozzle 6! together with air weight controller 63, both of which are known to the art and do not form part of this invention. Controller 63 acts by lever as shown on rheostat 64 of motor 22 thus coordinating fuel quantity to air quantity. It is immaterial for the purposes of this invention in what manner the supercharger is driven. Normally the hot air in pipe l2 will be under subatmospheric pressure. In order to utilize some of that air for heating purposes outside the engine proper, exhauster 65 is provided, which may for example deliver air to an airplane cabin for heating it.

The heating of the auxiliary ignition chamber 26' may be effected by any available heat source, for example a blow torch or a fire built up of wood branches, which may be important in emergencies.

While a large number of hydrocarbons conform with the requirements of this invention, for example paraffines, anthracene, cresol, ceresin and hydrocarbons containing oxygen, naphthalene is considered a preferred fuel since it has been found to possess valuable properties as an engine fuel.

Manifestly variations other than those specifically set forth may be resorted to and parts may be used without others in the practice of my in- 10 vention within the scope of the appended claims.

Having now fully described my invention, I claim:

1. In a reciprocating internal combustion enine comprising at least one cylinder, a" piston reciprocable in said cylinder, ignition means in said cylinder, and a gas heated vaporizer for fueling said engine with particulate solid hydrocarbons having melting points substantially above ambient air temperatures and evaporating substantially without residue, and conduit means connecting said vaporizer to said cylinder, the combination of means for supplying .an air stream, conduit means for said air stream connected to a combustion chamber external to the engine cylinder, means for feeding solid particulated hydrocarbons to said combustion chamber, means for initially heating and igniting a portion of said hydrocarbons in said chamber for creating a self-supporting combustion therein, and conduit means for bringing the hot products of said combustion in contact with said vaporizer for preheating it prior to starting the engine.

2. In a reciprocating internal combustion engine comprising at least one cylinder, a piston reciprocable in said cylinder, ignition means in said cylinder, and a gas heated vaporizer for fueling said engine with particulated solid hydrocarbons having melting points substantially above ambient air temperatures and evaporating substantially without residue, and conduit means connecting said vaporizer to said cylinder, the combination of means for supplying an air stream, conduit means for said air stream connected to a combustion chamber external to the engine cylinder, means for feeding solid particulated hydrocarbons to said combustion chamber,

means for initially heating and igniting a portion of said hydrocarbons in said chamber for creating a self-supporting combustion therein, and conduit means for bringing the hot products of said combustion in contact with said vaporizer and at least part of the engine for preheating I these parts prior to starting the engine.

3. In a reciprocating internal combustion engine comprising at least one cylinder, a piston reciprocable in said cylinder, ignition means in said cylinder, and a gas heated vaporizer for fueling said engine with particulated solid hydrocarbons having melting points substantially above ambient air temperatures and evaporating substantially without residue, and conduit means connecting said vaporizer to said cylinder, the combination of means for supplying an air stream, conduit means for said air stream connected to a combustion chamber external to the engine cylinder, means for feeding solid particulated hydrocarbons to said combustion chamber, means for initially heating and igniting a portion of said hydrocarbons in said chamber for creat ing a self-supporting combustion therein, conduit means for bringing the hot products of said combustion in contact with said vaporizer for preheating it prior to starting the engine, means for feeding solid particulated fuel into said vaporizer, means for actuating said last named feeding means, and means for cranking the engine while the last named feeding means is idle and said vaporizer is preheated, whereby hot air is aspirated from the vaporizer to the engine cylsaid cylinder. a gas heated vaporizer for fueling said engine with particulated solid hydrocarbons having melting points substantially above ambient air temperatures and evaporating substantially without residue, and conduit means connecting said vaporizer to said cylinder, the combination of means for supplying an air stream. conduit means for said airstream connected to a combustion chamber external to the engine cylinder, means for feeding solid particulated hydrocarbons to said combustion chamber, means for initially heating and igniting a portion of said hydrocarbons in said chamber for creating a selfsupporting combustion therein, conduit means for bringing the hot products of said combustion in contact with the walls of said vaporizer for preheating it prior to starting the engine and during 'low load operation, and means for feeding solid particulated fuel into said vaporizer.

5. In a reciprocating internal combustion engine comprising at least one, cylinder, 9. piston reciprocable in said cylinder, ignition means in said cylinder, a gas heated vaporizer for fueling said engine with solid particulated hydrocarbons having melting points substantially above ambient air temperatures and evaporating substantially without residue, and conduit means conmeeting said vaporizer to said cylinder, the combination of means for supplying an air stream, conduit means for said air stream connected to a combustion chamber external to the engine cylinder, means for feeding solid particulated hydrocarbonsto said combustion chamber, means for initially heating and igniting a portion of said hydrocarbons in said chamber for creating fsupporting combustion therein, means for supplying a second air stream, conduit means for said second air stream connected to the interior of said vaporizer and thence to the engine cylinder, conduit means for bringing the hot products of said combustion in contact with the outer walls of said vaporizer to preheat it prior to starting of the engine, and means for feeding solid particulated fuel into said vaporizer.

6. In a reciprocating internal combustion engine comprising at least one cylinder, a piston reciprocable in said cylinder, ignition means in said cylinder, a gas heated vaporizer for fueling said engine with solid particulated hydrocarbons having melting points substantially above ambient air temperatures and evaporating substantially without residue, conduit means connecting said vaporizer to said cylinder, and a surface type air heater, the combination of means for supplying an air stream, conduit means for said air stream connected to a combustion chamber external to the engine cylinder, means for feeding solid particulated hydrocarbons to said combustion chamber, means for initially heating and igniting a portion of said hydrocarbons in said chamber for creating a self-supporting combustion therein, valved conduit means for ambient air connected to said surface type air heater and thence to the engine cylinder, conduit means for bringing the hot products of said external combustion in contact with the walls of said vaporizer and of said surface air heater, and means for feeding solid particulated hydrocarbons into said vaporizer.

'7. In a reciprocating internal combustion engine according to claim 4, conduit means from said external combustion chamber to the atmosphere disposed in heat transfer relationship to the external surface of the engine.

8, In a reciprocating internal combustion en- 1-2 gine according to claim 5, conduit means from said external combustion chamber to the atmosphere disposed in heat transfer relationship to the external surface of the engine.

9. In a reciprocating internal combustion engine according to claim -6, conduit means from said external combustion chamber to the atmosphere disposed in heat transfer relationship to the external surface of the engine.

10. In a reciprocating internal combustion engine according to claim 3, conduit means from said external combustion chamber to the atmosphere arranged in heat transfer relationship to the lubrication oil of the engine.

11. In a reciprocating internal combustion engine according to claim 4, conduit means from said external combustion chamber to the atmosphere arranged in heat transfer relationship to the lubrication oil of the engine.

12. In a reciprocating internal combustion engine according to claim 5, conduit means from said external combustion chamber to the atmosphere disposed in heat transfer relationship to the lubrication oil of the engine.

13. In a reciprocating internal combustion engine according to claim 6, conduit means from said surface air heater to the crankcase of the enine, disposed in heat transfer relationship to the lubrication oil in said crankcase.

14. In a reciprocating internal combustion engine according to claim 6, conduit means from said surface air heater for supplying hot air to a consumer other than the engine.

. 15. In a reciprocating internal combustion engine according to claim 3. electric resistance heating means for said ignition means in the cylinder for preheating the body of said ignition means prior to starting the engine.

.16. In a reciprocating internal combustion engine according to claim 4, electric resistance heating means for said ignition means in the cylinder for preheating the body of said ignition means prior to starting the engine.

17. In a reciprocating internal combustion engine according to claim 5, electric resistance heating means for said ignition means in the cylinder for preheating the body of said ignition means prior to starting the engine.

18. In a reciprocating internal combustion engine according to claim 6, electric resistance heating means for said ignition means in the cylinder for preheating the body of said ignition means prior to starting the engine.

. FREDERICK NETI'EL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS