US2481631A - Internal-combustion heater burner and ignition means therefor - Google Patents

Description

Sept. 13, 1949.

v. N. TRAMONTINI 2,481,631 INTERNAL-COMBUSTION HEATER BURNER AND IGNITION MEANS THEREFOR Filed Au 17, 1946 2 Sheets-Sheet 1 0121/21) ,dfiy dial/megs.

Sept. 13, 1949. v. N. TRAMONTlNl 2,481,631

INTERNAL-COMBUSTION HEATER BURNER AND IGNITION MEANS THEREFOR Filed Aug. 17, 1946 2 Sheets-Sheet 2 [lave/$60 1 ems, 1a, 1949 UNITED INTERNAL-COMBUSTION HEATER BURNER AND IGNITION MEANS THEREFOR Vernonn. Tralnontini, Indianapolis, Inc, .8- signor' to Stewart-Warner Corporation, Chiu lit. a corporation of Virginia Application August 17, 1946, Serial No. 691,190

- 3' Claims. (01. 15 8-28) The present invention relates to heaters and more particularly to a small size, high output heater for automobiles and other vehicles.

The heater oi the present invention is intended for operation with gasoline or similar liquid lrvdrocarboris as the fuel and may be considered as an improvement over the heater forming the subiect matterotthepresentassigneescopendingapplication of George W. Allen and Vernon N. Tramontini for "Heater" flled June 14, 1946 and which has been given Serial No. 676,776; Because of the similarities of the two heaters, reference is made to this copending patent application for a more detailed disclosure of the common subject matter. In general, the two heaters are similar excepting forthe burners and certain of the control equipment. The improved burner and equipment directly operated therefrom and attached thereto forms the subject matter of the present invention.

It is an object of the present invention to pro- ,vide a novel automobile or similar type combustion heater having improved starting characteristics, particularly when flooded or when hot, without sacrificing other desirable characteristics, such as the ability to start in extremely cold weather.

Another object is to provide a novel heater having an improved igniter control arrangement formed in conjunction with the burner.

Yet another object of the present invention is to provide an improved heater and burner therefor having the above characteristics together with good performance over a wide range of heat output, so that the heater is well adapted for quickly bringing the temperature within an automobile to a comfortable level even in extremely cold weather while also having the ability to operate eiliciently at a very low rate of heat output, such as may be desired for maintaining the temperature within the vehicle only slightly above ambient in mild weather.

Still another object of the present invention is to provide an improved automobile or similar type heater which may be manufactured at low cost and which has desirable control characteristics.

Yet another object of the present invention is to provide a novel heater having the above advantages and which has good life characteristics and requires aminimum of attention in service.

Other objects and advantages will become apparent from the following description of a preterred embodiment of my invention which is illustrated in the accompanying drawings.

In the drawing in which similar characters of 2 reference refer .to similar parts throughout the several views:

.Fig. 1 is a sideview of a heater embodying the present invention with a portion thereof broken swag to show the burner in longitudinal medial sec on;

Fig. 2 end view 0! the burner end of the heater; Fig. 8 is a vertical transverse sectional view through a portion of the burner and may be con-' sidered as taken in the direction of the arrows substantially along the line 8-3 of Fig. 1;

Fig. 4 is a vertical transverse sectional view through a portion of the heater illustrating primarily the construction of an igniter switch for automatically tuning the heater igniter oil after combustion has been well sd and the association of the switch with the burner. This view may be considered as taken in the direction of the arrows substantially along the line t-d of Fig. 1;

Fig. 5 is a top view of the switch illustrated in Fig. 4; and

Fig. 6 is a vertical transverse sectional view through a portion of the burner and may be con-=- sidered as taken in the direction of the arrows substantially along the line ii- 3 of Fig. l.

The heater 0? the present invention comprises a cylindrical casing it through which air to be heated is passed, usually from left to right as seen in Fig. 1. For the purpose of making ventilating air duct connections, a fiange i2 is shown at the left-hand end of the heater in Figl l and may, of

course, also be used at the opposite end or other means may be used as desired. Air to be heated lated therethrough by means of a scoop locatedin the exterior air stream, such scoops usually being attached to the fuselage or formed in the lead ing edge of the airplane wing.

Within the casing I ii the air to be heated passes around and through a heat exchanger it which may be of any suitable construction, but for the present purpose will be assumed to be of the type more fully described in the previously referred to copending application. heated a burner It, to be described in greater detail presently, supplies hot products of combustion to the space within an inner cy Inthistim shell II.. This shell is, therefore, heated and the hot products of combustion pass therefrom through a longitudinally extending sloth not shown, into an outer annular space formed between an outer shell 22 and an intermediate shell 24. .The hot products of combustion in this space therefore heat the shells 22 and 24 and thereafter pass from the heater throughan exhaust fitting 26 located adjacent the lower side of the heater and opposite the previously referred to slot. The fitting 26 is connected to the space 26 by way of an opening through the outer shell 22. Ventilating air to be heated passes longitudinally through the annular space between the casing i8 and the outer shell 22 and also longitudinally through the substantially annular pass sage l4.

The burner I6 is formed of sheet metal of an alloy having good resistance to corrosion at high temperature. Certain of the stainless steel alloys are suitable for this purpose and are preferably used for forming the burner l8 and the three cylindrical shells I8, 22 and 24.

The burner I8 is former as a frustum of a cone and is so arranged within the heat exchanger that the smaller end 28 thereof is open and serves as the outlet for the products of combustion. The side wall or conical surface 38 of the burner extends toward the adjacent end of the heater and has a progressively increasing diameter and at its opposite end is closed by a back plate 32 which is substantially in the plane of the inlet end of the heat exchanger.

Air for combustion is supplied to the burner by a centrifugal blower 34 driven by a small electric motor 36, air being drawn inwardly at I an opening 38 to a blower impeller 48 which forces the air outwardly and through an outlet 42 connected to a combustion air tube 44. This tube connects adjacent the surface of the heater by means of a fitting 46 with a similar air tube 48 located within the heater and which passes inwardly to a position within the inner shell 18 where it is curved so as to extend into the open end of the burner. Within the burner the tube 48 is connected to an elbow 68 which directs the air downwardly and tangentially in such manner as to cause it to follow a circular path inside the burner shell and against the back wall 82. In order to confine the air against the back wall for a portion of a revolution, a semicircular baflle plate 52 extends from the elbow fitting 60 to the lower surface of the burner where it is secured by resistance welding or by any other suitable means. The baille 52 is arrangedin a vertical plane and extends from side to side of the burner from approximately the center of the burner downwardly.

The back plate 32 of the burner is provided with a generally rectangular opening 54 in the lower portion thereof, this opening being closed by a sheet metal cup or pocket-forming member 56 with its open end 58 fitted to the opening 54, the back plate 32 and contiguous edge of the cup 66 being sealed together by welding,

For convenience in reference, the closed end wallof the pocket forming member 56 is indicated by the numeral 58. The lower surface or floor 60 of the pocket slopes generally downwardly from the rear wall 58 to the opening 64 so that, as will be described presently, any gasoline entering the pocket will flow downwardly into the conical shell 38 of the burner. In other words, the downwardly sloping floor of the pocket 68 causes gasoline to now forwardly while the rearwardly sloping wall 36 ofthe burner. being pitched in the opposite direction, causes the liquid fuel to be concentrated in the triangularly shaped zone at the juncture between the back wall 82 and the edge of the conical surface 36. The pitch of both the surfaces 80 and 86 is suiliclent to cause the liquid fuel to be collected as above described regardless of whether the vehicle is operating upon a level surface or whether it is climbing or descending hills.

With the liquid fuel in this location his in direct contact with the swirling air flowing from the fitting 50. Thus, the fuel and air are rapidly and easily mixed to provide efllcient combustion. Thi mixing is promoted by passing the air tube 48 for a short distance tl'. ough the zone occupied by the hot products of combustion so that the combustion air is preheated before entering the burner.

At its closed end 58, the pocket 56 is provided with a fitting 62 welded or brazed thereto which has a threaded opening 64 to receive the threaded head portion of an igniter 66. The igniter 66 is of the hot wire type and comprises a small diameter cylindrically wound gloosecoil 68 located coaxially within a shell 18. Preferably the coil is formed of Nichrome or'similar high temperature resistance wire and has its outer end secured to the end of the shell 10 in any suitable manner, such as by staking in place and then brazing the joint thus formed. The opposite end of the coil 68 is similarly secured, that is, by brazing or the like, to the head of a screw 12 which passes through the head of the igniter body 66. In order to prevent electrical contact between the screw I2 and the body of the igniter,

I the portion of the screw 12 passing through the igniter body is insulated by a bushing of ceramic or similar material. The screw 12 serves as one terminal for the igniter and is secured by nuts 14 to an electric lead I6, the other terminal of the igniter being grounded.

In order to provide better starting characteristics the igniter shell 18 has a row of perforations 18 in the side wall thereof to facilitate the flow of fuel and air mixture around the igniter coil as will be described in greater detail presently. The igniter shell 18 is enclosed coaxially within a larger cylindrical sleeve 88, the rearward end of which is secured by brazing or the like to the previously mentioned fitting 62, the opposite end of the shell 86 projecting somewhat beyond the end of the igniter shell 10. So as to provide proper air flow characteristics 'within the pocket 56 and to prevent excessive turbulence a pair of vertical longitudinally extending baffles 82 and 84 are arranged below and above the sleeve 8ll'respectively. The lower baflie 82 extends from the sleeve 88 to the bottom of the pocket 56 at approximately the center line of the sleeve and pocket while the upper baflle 84 extends from the sleeve to the upper surface of the pocket in alignment with the lower baffle 82. These two baflles prevent the rapid rotational flow of air within the conical chamber 30 from causing excessive turbulence within the rearward portion of the pocket 56.

The fitting 62 is formed to provide a vertical passage 86 open at the top which communicates with a fuel tube 88 extending to the top of the heater and which is there connected to a fuel control valve 80. This valve may be of the simple on-oil' type and it may also provide high and low positions. The particular valve forms no part of the present invention, but a suitable valve for this purpose is described in the present assignees eopending patent application of George W. Allen. filed May 4, 1948, for "Control Valves" and which has been given Serial No. 667,395. The fuel tube has an internal diameter of approximately a quarter-of an inch or so and contains a wick 02 formed of heat and corrosion resistant material, l'br this purpose I have found that a wick formed of braided stainless steel wire is well suited. This wick extends for a considerable distance up into the tube. as at its {upper end, while the lower end passes through an opening in the upper rear corner of the sheet metal cup forming the chamber 00, so that the lower end of the wick projects into the pocket andrests against the upper surface of the shell 00. us, gasoline flowing downwardly in the tube 00 to the heater will be absorbed by the wick 02 and will be evenly fed out upon the surface of the shell 0|.

To-start the heater of the present-invention, the igniter 00 and the blower motor 80 are energiaed, thereby starting the delivery of combustion air to the burner and at the same time heating the element 00 of the igniter. Simultaneously, the fuel is turned on by energizing the fuel control valve 00 and, if desired, the ventilating air blower, not shown, may be started or, in some systems, starting of the ventilating air blower may be delayed until the heater reaches a predetermined temperature. In any event, so far as ignition is concerned, the important considerations are that the igniter be energized, that the fuel be turned on, and that combustion air be supplied to the burner. Under these conditions,

provided with a contact I04. An insulating block of ceramic material I00 is fitted over the stud 00 and rests against the upper surface of the strip I02 and upon its upper surface supports a terminal strip I00 formed of mild steel, brass, or the like.

The strip III is also insulated from the stud It by the ceramic bushing I00 and has an eye I I0 formed at its outer end to facilitate soldering to an electrical conductor H2. The opposite end of the strip projects from the bushing I00 in the direction of the contact I04 and is bent so that its end Ill supports the end of a spring metal strip II! having a contact II! associated with the contact I04. v The strip III lies in face to face relationship with the terminal strip I00 so as toinsure good electrical contact between these members. Outwardly of the bushing I00 the spring strip II 0 is formed with a loop or S-bend I20 so as to provide considerable flexibility. By bending the end portion Ill of the soft metal terminal strip, the contact IIO may be properly located while the spring action of the strip I II permits the contact IIB to follow the contact Ill upwardly without unduly stressing either the bimetal strip I02 or the spring metal strip I I0.

When the heater is cold, the contacts I04 and I I0 are separated with the strip II8 supported the igniter rapidly reaches ignition temperature v extremely cold weather and this vapor is mixed with air which finds its way into the pocket, thereby forming a combustible mixture which is in turn ignited by the hot wire element of the igniter 00. Flame, therefore, flashes out into the main burner comprised of the shell and the back plate 22. Meanwhile, gasoline will have passed over the shell 00 and into the bottom of the pocket 08 from which it drains into the main burner in which location it is subjected to the rapidly moving air stream delivered from the fitting 50. The air flowing over the gasoline mixes with the vapor and forms a combustible mixture which is ignited by the puff of flame from the igniter pocket. Combustion, therefore, is started in the main burner and proceeds until extinguished by deenergizing the valve 00.

Soon after combustion has been started, it is desirable to de-energize the igniter, both for the purpose of preventing the wastage of electrical energy and also because de-energizing the igniter prolongs the life of this element. The switch for accomplishing this purpose is indicated generally by the numeral 04 and comprises a headed stud 08 which projects upwardly through an opening 08 in the upper surface of the igniter pocket 00. After this stud has been located as above described with the head I00 against the inner surface of the top of the igniter pocket, it is secured by resistance welding or by brazing or in any other suitable manner to insure that it will remain fixed and that no leakage through the opening 00 will take place.

A bimetal strip I02 has an opening therethrough at one end to fit the stud 00 and is positioned with its lower surface over a considerable area in direct contact with the top surface of the igniter pocket. This strip I02 at its outer end is by the end I of the terminal strip I00. When combustion is initiated in the combustion chamber, the temperature of the shell 50 will rapidly rise and heat therefore will be conducted from the top of the shell to th strip I02, thereby causing it to fiex upwardly until the contacts I 04 and I00 are closed. They remain closed until the metal of the combustion chamber has subsequently cooled below some predetermined value. The spring metal strip I20 is held in place, along with the terminal strip I00, the bushing I00 and the bimetal strip I02 by a washer I22 formed of insulating material which is clamped against the upper surface of the strip I20 by a nut I2l threaded upon the stud 00.

The switch just described is enclosed within a sheet metal cover I28 which slips over the stud 98 and has its lower edge seated around a pressed- I out portion I20 of the upper surface of the igniter pocket 58. This cover is held in place by a nut I28 threaded to stud and has a slot I30 at one side to permit passage of the terminal strip I00.

Contacts I40 and lit are connected in series with a relay coil and a source of electrical energy,

so that the relay is energized when the contacts are together. Energization of the relay opens a circuit from the electrical energy source to the igniter, thereby allowing the latter to cool after combustion has been established.

Having described my invention, what I claim as new and useful, and desire to secure by Letters Patent of the United States, is:

1. A liquid fuel burner comprising means forming a substantially conical combustion chamber disposed upon a horizontal axis and having a closed large end and an' open small end, means for admitting combustion air into said combustion chamber, means forming a pocket communicating with substantially the bottom of said combustion chamber through said closed end. anelectrical igniter of the hot wire type horizontally disposed within said pocket, a generally cylindrical shell enclosing said igniter, and means including a wick for delivering liquid fuel against said shell.

2. A liquid fuel burner comprising means forming a combustion chamber, means for admit- 7 tin combustion air into said combustion chamber, means forming a pocket communicating with said combustion chamber, an electrical igniter of the heated element type disposed within said pocket, a generally cylindrical shell partially enclosing said igniter and adapted to be heated thereby, and means including a wick in contact witl-nsaid shell for delivering liquid fuel to said pocket.

3. A liquid fuel burner comprising means iorm=- ing a substantially conical combustion chamber having a closed large end and an open small end, means forming-a combustion air pipe arranged to introduce combustion air tangentially in a transaxial direction into said combustion chamher, means forming a small ofiset pocket communicating with said combustion chamber through said closed end at the bottom thereof,

an electric igniter of the hot wire type horizontally disposed within said pocket, a generally cylindrical shell partially enclosing said igniter and disposed to be heated by said igniter, and means including a metallic wick in contact with said shell for delivering all of the liquid fuel required by said combustion chamber to said pocket.

VERNON N. TRAMQNTINI.

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

UNI'I'ED STATES PATENTS

Images