US2411040A - Liquid fuel preparing apparatus - Google Patents

Description

1946- H. B. HOLTHOUSE, JR 2,411,040

LIQUID FUEL PREPARING APPARATUS Filed April 7, 1943 2 Sheets-Sheet 1 NOV. 1946- H. B. HOLTHOUSE, JR 2,411,040

LIQUID FUEL PREPARING APPARATUS Filed Apfil 'r, 1943 2 Sheets-Sheet 2 Patented Nov. 12, 1946 UNITED STATES PATENT OFFICE 2,411,040 I LIQUID FUEL PREPARING APPARATUS Harry B. Holthouse, Jr., Chicago, Ill., assignor to Galvin Manufacturing Corporation, Chicago, 111., a corporation of Illinois Application April 7, 1943, Serial No. 482,l

Claims. (01. 158-28) l 2 This invention relates generally to means for is passed through the tube at all times of coil optreating a liqu d f or bu g and in p eration to prevent the passage into-the tubeof ular to such means for preparing a liquid fuel any liquid or heated fuel for contact with the for burning in a heater of combustion type. coil.

Many types of liquid fuel burners use elec- 5 Further objects, features, and advantages of tric heating systems having an electrical heater this invention will become apparent from the of resistance type for heating the fuel to be following description when taken in connection burned or fo igniting the fuel for burning. These with the accompanying drawings in which: electric heaters are generally of coil type and in Fig. 1 is a sectional view of a combustion type their operation the fuel is usually passed into heater e bo ying e fuel treating mean of this direct contact'with the coil. The fuel contacting invention, with the combustion chamber of the the coil cools the same and also covers it-with a heater being shown in development for the purfilm of soot so as to appreciably reduce its elfipose of clarity; ciency for heating purposes. Further the fuel Fig. 2 is an enlarged sectional detailed view 0 contacting the coil sets up a corroding action the invention, which is indicated generally in which gradually destroys the coil. As a result Fig. 1 to show its relative assembly with the rethe heat generated by the coil is retained within mainder of the heater; the coil so that the coil operates at temperatures Fig. 3 is a sectional view as seen along the line in excess of those for which it is designed and 33 in Fig. 1; and soon burns out. Another factor which appreci- Fig. 4 is a view in perspective of an insulatably impairs the life and operation of these prior ing supporting member for a heating coil in the art heating coils arises by .virtue of the location fuel treating means.

of the coil in a position where it is exposed to the In practicing this invention there is provided flames of combustion. When the coil is thus an air heating system of internal combustion exposed to the action of the flames it generally type having an air and fuel mixing device in fluid becomes heated above its normal operating temconnection with a combustion chamber. The perature with such excess heat accelerating the mixing device includes a combination electric Corroding action of the fuel on the coil. All of heater unit for conditioning the air and fuel to these factors contribute materially to shortenbe burned and for igniting such air and fuel ing the operating life of the coil and reducing mixture for burning. The electric heater unit the efiiciency of its operation over the span of includes a heating element comprised of a single its service life. resistance coil supported in a spaced relation It is an object of this invention, therefore, to within a heat conducting tube open at one end provide animproved means for preparing a liquid to the combustion chamber.

fuel for burning. Air and fuel introduced into the mixing device Yet another object of this invention is to proare heated while passing about the heat conductvide an electrical heater for preparing a liquid ing tube to vaporize the fuel for mixing with the fuel for burning in which the liquid fuel is preair. The vaporous air and fuel mixture is directvented from contacting the coil. ed into the effective igniting zone of the coil at Another object of this invention is to provide the open end of the tube for ignition. In order a liquid fuel conditioning means which is simple to eliminate any portion of the vaporous mixture and inexpensive in construction, enlcient in opfrom contacting the coil, with the deleterious reeration to' prepare a combustible air and fuel sults mentioned above, air is forced through the mixture of uniform characteristics, and in which tube in a direction towards the open end, heated n E ec i 1 for Preparing the fuel for mixing to a temperature above the ignition temperature of with the air functions as a combination heating the vaporous mixture, and then moves into the and igniting unit without at any time coming into combustion chamber where it ignites the vaporcontact with the air and fuel mixture or being ous mixture. At no time, therefore, is the coil exposed to the flames of combustion. contacted by the fuel during either the heating A feature of this invention is found in the or i niting of the fuel so that all difficulties arisprovision of a liquid fuel treating means in which ing from the fuel contacting the coil are entirely an electric resistance for treating and igniting eliminated. To further prolong the life of the the fuel is supported in a spaced relation within heating coil the vaporous mixture on being iga heat conducting tube having one end open to nited is immediately projected away from the the flow of the treated fuel. Air under pressure coil for burning at some point away from the 3 coil. The coil is thus entirely out of the flames of combustion and not subjected to the intense heat of the burning mixture.

Referring to Fig. 1 of the drawings a-heatlng unit embodying the liquidfuelconditioning means of this invention is seen-to include a housing l which is divided longitudinally over. subertically extendstantially its entire length by ing partition member to' a mechanical compartment l2 and a heating oompartmentfor a combustion chamber l3. The combustion chamber, shownin development in Fig. 1- for the plate I4 and at its-opposite end'by theibettom l3 of a substantially cup shaped member I which defines inpart an air supply chamber I! in axial alignment with the combustion chamber 13. r The combustion chamber I3 is divided longitudinally into four axially extending but connected passagesJSa-Hd by a partition member 2| of substantially X-shape (Figs. 1 and 3). An inlet 22 and an outlet 23 for the combustion chamber are formed in the bottom l6 of the cup shape member II in communication with the passages Ila and |3d, respectively. The liquid fuel treating means 24 of this invention, is located-in the inlet 22 and I and is separated from an equalizing chamber 53 by a perforated plate 34. The equalizing chamber 63 in turn is both defined and separated from the combustion chamber passage Ila by a perforated purpose of clarity, is closed at one end by a cover heat insulating plate ll. Extended substantially axially through the housing 43 and supported in the perforated plates 34 and 53 and'proiected outwardly from the closed end of the casing. is a combination electric heating andigniting 'unit 51.

The combination unit 51 includes a tubular copper sleeve 33 having an enlarged portion supfrom the equalizing chamber 53 through the plate extended within the air supply chamber IS. A tail pipe assembly 26 for carrying exhaust gases from the combustion chamber I3 is extended from the outlet 23 through the air supply chamber I8 and outwardly from the heater at-the housing end 21.

The outer wall or body portion of thecombustion chamber l3 carriesangularly spaced axially extending fins 28. The fins 23 have asleeve 29 positioned about their outer ends to form annular passages 3| about the combustion chamber l3 for the coil 53.

air to be heated. The air to be heated is admitted into the passages 3| through an annular chamber v 32 connecting these passages with the mechanical compartment l2 and is circulated about'the combustion chamber through the passages 3| by a fan 33 located within the compartment l2 and mounted on a shaft 34 of an electrical motor 36.

The compartment l2, chamber 32 and passages 3| are separated from the air Supply chamber l8 by a partition member 31 extended transversely of the housing Ill. Thus from Fig.- 1 it is seen that the airsupply chamber I3 is defined by the cup member II, the partition member 31 and the end 21 of the housing l3. Air circulated by the ported in the plates 54 and 53 for receiving in a spaced relation a resistance coil 59. The end 64 of the enlarged tube portion projects outwardly 53 and is open to the outlet end SI of the mixing means, 24. A reduced section of the sleeve 53 .extends outwardly from the closed end of the casing 43 and into the air supply chamber I3.

The end 63 of the reduced tubeportion is closed by an insulated member 65 which carries a coil lead 13 electrically connected with one end of The opposite end of the coil is grounded tothe tube 53 as indicated at 15; The

coil 59 is wound on a mica tube 3| which has both heat and electrical insulating characteristics. In one commercial embodiment of the invention the resistance coil 53 is composed of a #20 wire capable ofbeing heated to about 1600 degrees Fahrenheit with 12 volts at 6 amperes which temperature is capable of preparing and igniting one kind of fuel to be burned. The coil' 59 is thus rather delicate and of a small size and sensitive to both operating currents and temperatures. In other words any intense heating of the coil by the fiames ofcombustion, by accumulated generated heat within the coil due to the cor'roding of a portion thereof, or by a shorting out of part of the coil so that an overload current is applied on the remainder of the coil will either destroy the coil fan 33 is thus confined for travel within the com- .partment l2 and passages and is discharged from the passages 3| through an outlet 38 which is connected to a space to be heated.

The airsupply chamber l8 receives air from a fan 33 mounted on the motor shaft 34 which is ioumaled in the partition plate .31, with an inlet 4| for the fan 33 being formed in the housing end 21. It is seen, therefore, that the fans 33 and 39 are operated by the motor 33 and mounted di-.

rectly on the motor shaft 34. The. motor 3 is also used in the operation of a fuel pump 42 which is illustrated as being of a solenoid type. A breaker assembly 43 for controlling the energization of the pump 42 is operatively associated with the motor shaft 34. Fuel for the pump 42 is supplied from a suitable source (not shown) through a pipe 44 and is delivered through a pipe 43 to a fuel injection nozzle" formed as a part of the air and fuel mixing or treating means 24.

I 3 The pump '42,,motor 33 and fan 33 are thus all located within the mechanical compartment H which has an inlet opening 43 for supplying either fresh or recirculated air to the fan 33 for delivery or materially reduce its heating' efilciency and service life.- a

In the operation of the air and fuel mixing ,means 24 the fuel delivered to the injection nozzle 41 by the pump 42 is introduced into the mixing chamber I2,-the fuel nozzle being located within the air supply chamber l3 and mounted directly on the casing 43 at the mixing chamber 52 (Fig. 2). A portion of the air for mixing with the fuel enters the nozzle 41 through ports 62 and.

travels with the fuel into the mixing chamber 52. Additional air to be mixed with the fuel in the mixing chamber 52 is admitted directly into the mixing chamber through apertures 33 formed in the casing 43 about the fuel injection nozzle 41. r

The fuel within the mixing chamber 32 is heated by the heating unit 51 'and vaporized for with the air in the mixing chamber. The casing 43 and the partition plate 54 are composed of a heat conducting material and are in thermal connection with the combination'heating and igniting unit 51 so as to readily receive heat radiated to the tube 53 from the coil I3. The vaporcus air and fuel mixture passes from the mixing chamber 52 into the equalizing chamber 53' through the perforated plate 54. The eq ualizing chamber 33 in cooperation with the heat insulatmixture and to distribute the mixture substantially uniformly over the entire cross section of the casing 49 so that a mixture of substantially uniform fuel characteristics passes through the perforated heat insulating plate 56 into the effective igniting zone of the combination unit 51.

The air and fuel introduced into the mixing chamber 52 passes about the combination unit 51 in a direction generally toward the outlet 5| of the fuel preparing means 24. After traveling through the apertured plate 56 the mixture is free to flow across the open end 64 of the tube 58 and into the effective igniting zone of the combination unit 51 adjacent the tube end 54 where it is ignited by the heated air projectedfrom the combination unit 51, which functions in the manner explained below to discharge heated air into the fuel and air mixture. In other words, the air traversing the tube 58 is heated by the coil 59 to a temperature exceeding the ignition temperature of the fuel mixture and when projected outwardly from the end 64 of the tube 58 effects ignition of the fuel mixture.

As was previously mentioned it is desirable that any liquid or vaporous mixture be prevented from contacting the coil 58 because of the resultant injury to the coil. It is apparent, of course, that by virtue of the coil 58 being fully enclosed within the tube 58 in the mixing and equalizing chambers 52 and 53, respectively, that the mixture in these chambers only contacts the tube 58. Although the mixture about the open end 64 of the tube 58 flows generally in a direction away from the tube 58 and toward the open end 5| of the mixing means 24- any tendency of the vaporous mixture to pass through the open tube end 84 and into contact with the coil 59 is eliminated in the following manner.

The tube 58 at the junction of its enlarged and reduced sections carries an insulating supporting member 16 (Figs. 2 and 4) of substantially T- shape in cross section, with the stem portion 11 of the T being fitted within the reduced tube section and the cross arm portion 18 located within the enlarged tube section and against the shoulder formed at the junction of these two sections. The member 15 has an axial bore 18 for receiving the coil lead and cooperates with the insulating member 85 to support the lead 18 in a spaced relation within the tube 58. A slot 8i extending axially the full length of the member 16 forms an air passage with the wall of the tube 58, which passage fluid connects the two sections of the tube 58. That portion of the reduced section of the tube 58, which is positioned within the air supply chamber l8, has an aperture 88 which permits air from the chamber I8 to pass through the tube 58 and outwardly from the tube at its open end 64. Since the pressure of the air in the supply chamber I8 is the only pressure which acts on the air and fuel within the mixing means 24 and to the outside of the tube 58, it is seen that a like air pressure is provided within the tube 58 which counteracts the external air pressure at the open tube end 54. As a result any tendency of the vaporous air and fuel mixture to enter the tube 58 at its open end 64 is opposed by a like pressure within the tube 58 which prevents the mixture from passing into the tube and into contact with the coil 58. It is seen, therefore, that the coil operates at all times within an airspace free of any liquid or vaporized fuel. The quantity of air passing through the tube 58 is such as not to appreciably cool the coil 59 but is sufficient to maintain an air pressure within the coil which is at least equal to the pressure acting on the air and fuel mixture at the open tube end 84. This air mixes with the vaporous air and fuel mixture adjacent the tube end 64 and is burned with the mixture in the combustion chamber l3. The flow of air through the tube 58 and theflow of the mixture through the mixing means 24 in a direction toward the outlet 5| carries the ignited mixture into the combustion chamber l3 and out of the mixing means 24 so that the coil is not exposed to the flames of combustion.

From a consideration of the above description it is seen that the invention provides an apparatus for preparing and igniting a liquid fuel for burning in which an electrical heating element, used for heating the liquid fuel to at least a vaporizing temperature for mixing with air and for igniting the vaporous mixture for combustion, is always out of contact with any portion of the liquid fuel and air and fuel mixture. The heating element is located in a tube having an air flow therethrough and operates at all times in an air space so as to be entirely free of any corroding action by the fuel. The heating element is thus able to operate over a prolonged service life with maximum efliciency.

Although the invention has been described and illustrated with respect to a preferred embodiment it is to be understood that it is not to be so limited since modifications and changes can be made which are within the fully intended scope of the invention as defined by the appended claims.

I claim:

1. In internal combustion heating apparatus which is provided with means defining a combustion chamber, a fuel and air mixing unit opening into said combustion chamber and means operative to pass fuel and air through said unit to said chamber, electrical heating means open to said combustion chamber but removed from the combustion zone therewithin and positioned to preheat the fuel and air during its passage through said unit into said combustion chamher, and means for circulating air about said heating means out of contact with said air and fuel mixture and for discharging the air into the mixture adjacent the point of delivery of the mixture to said combustion chamber whereby the circulated air is heated to a temperature above the ignition temperature of the mixture and effects ignition of the mixture upon contacting said mixture at a point removed from said heating means.

2. In internal combustion heating apparatus which includes means defining a combustion chamber and means defining an air pressure chamber adjacent one wall of said combustion chamber; a fuel and air mixing unit disposed in said pressure chamber and provided with an outer tubular member communicating with said pressure chamber and having an outlet end opening into said combustion chamber, an inner tubular member disposed within said outer tubular membeer to provide a space therebetween, means for moving fuel and air through said space into said combustion chamber, said inner tubular member having an end communicating with said combustion chamber adjacent the outlet end. of said outer tubular member and an opposite end communicating with said pressure chamber, whereby air may flow from said pressure chamber through said inner tubular member to mix with inner tubular member to preheat the fuel and air mixture during its passage through said space and to heat the air traversing said inner tubular member to a temperature exceeding the ignition temperature of the fuel and air mixture traversing the outlet end of said outer tubular member.

3. Apparatus for preparing and igniting a combustible fuel for burning, including air and fuel mixing means having an outlet, a combination heating and ignition unit in said mixing means including a hollow member havng an open end adjacent said outlet, an electrical heating element within said hollow member having one end adjacent the open end of said hollow member, a portion of the heat from said heating element being radiated to said hollow member to preheat the fuel and air in said mixing means, means directing the flow of fuel and air mixture about the open end of said hollow member and in a direction generally toward said outlet, means for transmitting air through said hollow memberabout said heating element and for discharging the air into the fuel and air mixture at the open end of said hollow member, and means including said heating element for heating the air to a temperature above the ignition temperature of the mixture as it passes through said hollow member, whereby ignition of the mixture at a point removed from said heating element is effected by the heated air.

4. Apparatus for preparing liquid fuel for burning, including air and fuel mixing means pro-.

vided with an air and fuel mixing chamber having an outlet, a heating unit in said mixing means including hollow heat conducting means open to said outlet, means for moving air and fuel through said chamber for discharge through said outlet, an electrical heating element in said hollow means, the heat developed by said heating element being radiated to said hollowlmeans to heat and vaporize the fuel for mixing with the air during passage of the air and fuel through said chamber, means for transmitting air throughsaid hollow means in contact with said heatlnz element and for discharging the transmitted air into the vaporous mixture adjacent said outlet, and means including said heating element for heating the air transmitted through said hollow means to a temperature above the ignition temperature of the vaporous mixture, whereby ignition of the vaporous mixture is produced by the heated air upon intermixture thereof.

5. Apparatus for preparing and igniting a liquid fuel for burning, comprising air and fuel mixing means having an outlet, a combination heating and ignition unit in said mixing means includinga tubular member extending through said mixing means and provided with one open end adjacent said outlet and an opposite end open to the outside of said mixing means, means for moving air and fuel through said mixing means and about said tubular member in a direction from said opposite end of said tubular member toward said outlet, a portion of the heat developed by said heating element heating said air and fuel during passage of said fuel and air through saidmixing means and about said tubular member, means for transmitting air into said tubular member at said opposite end for passage into the vaporous mixture adjacent said outlet, and meansvincludlng said heating element for heating the transmitted air to a temperature above the ignition temperature of the mixture during its passage through said tubular member,

thereby to efl'ect ignition of the mixture by contact of the heated air with the mixture at a point removed from said heating element. 7

- HARRY B. HOL'I'HOUSE, Ja.

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