Патент USA US2404647код для вставки
Ju?y 23, E94. H, J. DE N. MQCOLLUM ET AL 2,49%647 HEATING APPARATUS Filed Oct. 15, 1942 5 Sheets-Sheet l R aw pwww?ww pmfwd‘ WW”, 4 yama06%M é n‘ “EH33? 23; 394% H. J. DE N. MCCOLLUM ET AL, 2,4M9%7 HEATING APPARATUS Filed Oct. 15, 1942 36, @ 5 Sheets-Sheet 3 - mm W3 Z 66%J0m.‘am. M Wm@W. , . V 6, ?‘ Patented July 23, 1946 2,404,647 " UNITED STATES PATENT OFFICE 2,404,647 HEATING APPARATUS Henry J. De N. McCollum and Lynn A. Williams, Jr., Chicago, 111.; said Williams assignor to Stewart-Warner Corporation, Chicago, Ill., a corporation of Virginia; Thelma McCollum ex ecutrix of said Henry_J. De N. McCollum?ie ceased Application October 15, 1942, Serial No. 462,074 r ‘ 8 Claims. (01. 126-116) 2 1 Our invention relates to heating apparatus and ‘ chamber 10, a ?nned heat exchanger l2 having a more particularly to heaters of the internal com mu?ler l4 located therein, and an outlet l6 bustion type particularly adapted for, but not lim through which the cooled products of combustion ited to, use in aircraft. ‘ are discharged to atmosphere. ‘ In heaters of the internal combustion type, it is common to provide ?nned heat transfer means for transferring heat from the products of com bustion to the ventilating air directed over the The heat ex changer I2 is enclosed ins, cylindrical casing, 18 through which ventilating air is directed by a ram or blower at the inlet end. of the duct 20 which supplies the ventilating air to the tapered inlet 22 of the casing IS. The heated ventilating air lating air. The heated products of combustion 10 discharged from the lefthand end of the casing heat transfer means by a ram or blower for circu l8 may flow directly into the aircraft cabin or are originally directed against the ?ns at one end other space to be heated, or may be distributed of the heat transfer means and where the hot to selected locations through a series of ventilat products of combustion ?rst come in contact with ing ducts, as desired. the ?ns, these ?ns are raised to a temperature A separate ram or blower forces air into the in which is much in excess of the temperature of 15 let end of a pipe 24, leading to a Venturi tube 25, other portions of the ?ns and particularly that . which receives part of the air ?owing through the portion adjacent the outlet end of the heater. pipe 24. A rich mixture of fuel and air is sup There is a practical limit to the temperature to plied to the throat of the Venturi tube 26 by a which the ?ns can be heated and this limits the total quantity of heat which can be given off b 20 pipe 28 connected to a primary carburetor 30. The pipe 28 has outlet openings 32 through which a heater of any given size and shape. ‘ the rich mixture of‘fuel and air formed in the An object of our invention is to provide heat primary carburetor 30 passes into the Venturi ing apparatus of the internal combustion type in tube 26 and mixes with ‘the air flowing there which local hot spots are eliminated and the heat transfer means is heated to a substantially uni 125 through to form a combustible mixture. This combustible mixture is discharged with a form temperature throughout its length. whirling motion through openings 34 in burner Another object of our invention is to provide heating apparatus wherein the temperature range between different parts of the heat transfer tube 36 and is initially ignited by the hot wires 38 of igniters 40. The igniters are provided with means is reduced to a minimum and stresses and ‘ shields 42 which are. open. to the combustion strains caused by great variations in tempera ture of di?erent portions of the heat transfer ‘chamber at each end, but which serve to protect the hot wires 38 against the direct discharge of combustible mixture through the openings in the burner tube 36. In the particular embodiment disclosed, three igniters are provided and these means are avoided. ‘ ' . Another object of our invention is to provide new and improved heating apparatus which is ex tremely light in weight and compact and has a high heating output. . igniters are arranged about the combustion chamber as most clearly shown in Fig. 4. It is understood, however, that any desired number and arrangement of igniters may be utilized and 4.0 the particular number and arrangement shown is In the drawings: not essential. Fig. 1 is a longitudinal, sectional view of a It will be understood that the igniters 40 are preferred embodiment of our invention; controlled by the usual thermostatic switch for Fig. 2 is a partial, sectional view taken inthe disconnecting these igniters from their source of plane of the line 2—-2 of Fig. 4; Fig. 3 is a partial, vertical, sectional view taken 45 electrical current when the heater attains normal operating temperature and thereafter ignition of on the line 3—3 of Fig. 1; the incoming combustible mixture is maintained Fig. 4 is, an irregular, sectional view taken on by the re-igniter 44. Only a single re-igniter is the line 4-4 of Fig. 1; Other objects and advantages will become ap parent as the description proceeds. ‘ Fig. 5 is a vertical, sectional view of the inlet end of a heater embodying a modi?ed form of our shown, as ordinarily a single re-igniter is suffi 50 cient to maintain combustion of the incoming fuel, but additional re-igniters may be provided if desired. The single re-igniter is illustrated as Fig. 6 is a partial, vertical, sectional view taken being located at the lower end of the combustion I on the line B—6 of Fig. 5. chamber and such location is desirable but not The heating apparatus shown in Figs. 1. to 4, inclusive, comprises, in. general, a combustion 55 essential. ' invention; and 2,404,647 ' 3 . The combustion chamber I 0 has an annular wall 46 which is spaced inwardly of the bases 48 of the hollow ?ns 50. The hot products of com bustion flow between the lefthand end 52 of the annular "wall 46 and the tapered .end 54 of the muffler into .the gas passages 56 extending length wise of the hollow ?ns. The tapered end of the 4 ucts of combustion ?rst engaged these ?ns. This further means is illustrated as comprising a comb 80 having an annular base 82 provided with teeth 84 which project through the inlet openings 58 ‘and lie parallelwto the bases of ‘the ?ns. ' The comb V8!) is preferably made of copper or other material having high heat conductivity. mu?ler provides a tapering annular passageway " The teeth 84 are of smaller diameter than the for the products of combustion and permits these openings 58 and permit cooling air to enter these hot gases to make their initial contact with-the 10 openings and flow lengthwise of the teeth 84 and hollow ?ns over an appreciable portion of the en the bases of the .hollow ?ns. The teeth 84 are tire length of these ?ns. This tendsto reduce the ' formation of hot spots in the bases :of the ?ns, but we have found it desirable to provide additional means for eliminating‘ such hot spots and for '15 maintaining the ?nned heat exchanger 12 at a preferably madeof such length that they extend for substantially the entire length of that por tion of ‘the hollow ?ns'which ?rst comes in con tact with the hot products of combustion and serve to prevent the formation of local hot spots more uniform temperature throughout its length. throughout this portion of the hollow ?ns. ' In the embodiment of Figs. 1 to 4, inclusive, The comb 80 may be either a complete annulus this additional means for eliminating hot spots or may be composed of a plurality of arcuate from the bases of the hollow ?ns comprises the 20 segments. In the embodiment shown, in the provision of an annular series of inlet openings drawings, frictional engagement between. the 58 in the wall Ell which connects the combustion chamber with the inlet end of the heat exchanger I'2. As most clearly shown in Figs. 3 and 4, each teeth .84 and the sides of inlet openings 558 is relied upon to hold the comb in ‘place, but any desired means may be provided for attaching the comb inlet opening is located immediately beneath the 25 to the conical air conduit 62, or any other suitable base ‘48 of .-a hollow ?n. Theseinlet openings 58 part of the heating apparatus; ‘ r . i communicate with the interior of the conicalex Our novel heating apparatus is‘ highly .e?icien't tension '62 of the pipe.“ and are supplied with air since the heat exchanger is maintainedat a sub by the same blower .or ram which supplies the stantially uniform temperature throughout its secondary air for the combustible mixture. The length and this uniform temperature may be the air passing through the inlet openings 58 ?ows maximum permissible temperature for ef?cient lengthwise of the bases of the hollow ?ns and operation. This heating apparatus can be made cools the bases of these ?ns adjacent their inlet extremely compact and of lightweight construc ends su?iciently to prevent the creation of hot tion and is particularly suitable for ‘use in air. spots ‘in these :bases where the hot products of 35 craft. It is not limited to such use, howeven'and combustion ?rst .come in contact with the ,?ns. may be utilized'for various other purposes. While . The cooling air admitted through the inlet our ‘novel means for eliminating hot 'spotsg-from openings 58 is not intended to ‘promote additional the ?nned heat exchanger. is particularly advan combustion adjacent the bases of the ?ns, but is tageous in heating apparatus having its own icom admitted solely for the purpose of cooling these 40 bustion chamber, our improvement isrnotineces bases adjacent theinlet end of the heat ex-i sarily limited to such use but may ?nd application changer. This cooling air mixes with the prod in exhaust type heaters or ‘other heatersrwhere ucts of combustion and this mixture ?ows length hot ?uid is supplied from outside sources. ' wise ,of ‘the hollow ?ns from'whence it passes into . While we have illustrated and described herein the chamber .64 formed between the lefthand end 45 only two embodiments of our invention, it ‘is to be of the mu?ler l4 anda plate 66 which closes the understood that our invention is not limited to lefthand .end of the heat exchanger 12. One or the details shown and described, but ‘may ‘as ‘more brackets 168 may be provided 'to attach the sume numerous other forms and is to be con plate“ to the casing [8. strued as including all variations and‘modi?ca "The outlet I6 is formed in a ?tting '10 mounted 60 tions falling within the scope of the appended‘ on the plate 66 and havinga threaded end 12 for claims. 7 attachment to an exhaust pipe communicating We claim: I with atmosphere. In some installations the ?t 1. Heating apparatus comprising a tubular ting 10 may be connected to the inlet of a suction heat exchanger of the hollow ?nned type, means blower or other suction producing means where 55 forming a combustion chamber in one end there it is desired to utilize such suction producing of for supplying hot products of combustion to means to create the necessary ?ow of combustible the interior of said heat exchanger, means for mixture into the heater and of the products of directing cooling air into said heat exchanger at combustion therefrom. The I?OW of ventilating the combustion chamber end thereof, and a'p'lu air through the ‘casing I8 may also be caused by 60 rality of parallel rods adjacent the bases of said suction producing means connected to the outlet ?ns to prevent the formation of hot spots in the end :of this casing rather than by pressure pro bases of the hollow ?ns ‘where the hot products ducing means at the inlet of the pipe 20 where of combustion ?rst contact these ?ns, said rods such an alternative arrangement is preferred. having parts in contact with said cooling air. Thermu?ler 14 has a sheet metal shell 114 which 65 '2. Heating apparatus of the class described, is ?lled with sound absorbing and heat resisting comprising a tubular heat exchanger of the hol material 16 such, for example, as glass wool or low ?nned type, means for supplying hot'?uid to stainless steel wool. The shell '14 is provided with one end of said heat exchanger and interiorly a plurality of small perforations 18 which form thereof; means for forming a blanket of cooling acoustic couplings between :the gas passages in 70 ?uid between the hot fluid and the bases of :the thehollow ?ns and the interior of the mu?ier. ?ns adjacent said end of the heat exchanger, In the modi?cation of Figs. 5 and 6, we have and heat dissipating membersin the path of vsaid provided further means in addition to the inlet cooling ?uid and inwardly of the bases iof said openings :58 :for preventing the creation of hot ?ns, said members having :partsextending be spots in the bases of the ?ns where the hot prod 75 yond said heat exchanger. ‘ : .Y . '. ‘ 1 . 5 2,404,647 3. In heating apparatus of the class described, the combination of a tubular heat exchanger of the ?nned type, means forming a combustion chamber located in one end of said heat ex changer and supplying hot products of combus tion thereto, said combustion chamber having an annular wall spaced from said heat exchanger, a carburetor for supplying a combustible mixture 6 comprising a tubular heat exchanger having hol low ?ns provided with bases, means forming a . combustion chamber for supplying hot products of combustion to one end of said heat exchanger, a mu?ier located in said heat exchanger and co operating therewith to direct the products of combustion lengthwise of the interiors of said hollow ?ns, means for supplying a combustible mixture to said combustion chamber, means for to said combustion chamber, means for supply ing air to said carburetor, an annular series of 10 directing ventilating air over said heat ‘ ex inlet openings for supplying air to the annular changer, a heat dissipating comb having teeth space between said combustion chamber and extending parallel to the base of said ?ns adja heat exchanger, each of said openings being lo cent the combustion chamber end thereof, and cated inwardly of the base of a ?n, said openings means for directing cooling ?uid against said a being supplied with air by the means supplying comb. air to the carburetor, and other means for di '7. In heating apparatus of the class. described, recting ventilating air over said heat exchanger. the combination of ‘a tubular heat exchanger of 4. In heating apparatus of the class described, the ?nned type, means forming a combustion the combination of a tubular heat exchanger of chamber located in one end of said heat ex the ?nned type, means forming a combustion changer and supplying hot products of combus chamber located in one end of said heat ex tion thereto, said combustion chamber having an changer and supplying hot products of combus annular wall spaced from said heat exchanger, tion thereto, said combustion chamber having means for supplying a combustible mixture to an annular wall spaced from said heat exchanger, said combustion chamber, ‘an annular series of means for supplying a combustible mixture to inlet openings for supplying air to the annular. said combustion chamber, an annular series of space between said combustion chamber and heat inlet openings for supplying air to the annular exchanger, each of said openings being located space between said combustion chamber and heat inwardly of the base of a ?n, said openings being exchanger, each of said openings being located supplied with air by said ?rst means, a comb inwardly of the base of a ?n, said openings being 30 having teeth extending through said openings supplied with air by part of said ?rst means, and and a part exposed to said air, and second means second means for directing ventilating air over for directing ventilating air over said heat ex said heat exchanger. changer. 5. Heating apparatus of the class described, 8. A heating apparatus of the class described comprising a tubular heat exchanger having hol comprising a tubular heat exchanger of the hol low ?ns provided with bases, means forming a low ?nned type, wall means forming a combus combustion chamber for supplying hot products tion chamber at the rear end of the heat ex of combustion to one end of said heat exchanger, changer for supplying hot products of combus a muffler located in said heat exchanger and co tion to the interior of the heat exchanger, means operating therewith to direct the products of comprising a conduit for directing a supply of combustion lengthwise of the interiors of said combustion air into said combustion chamber hollow ?ns, means for supplyinga combustible and a separate supply of cooling air into said mixture to said combustion chamber, means for heat exchanger by a path which leads said air directing ventilating air over said heat exchanger, over the outer surface of said wall means of said and a heat dissipating comb having teeth ex combustion chamber and against the portions of tending parallel to the base of said ?ns adja ‘the ?ns adjacent the combustion chamber, and cent the combustion chamber end thereof, said other means for directing a supply of'ventilating comb having a part exposed to said ventilating air over the exterior of said heat exchanger. air. HENRY J. DE N. McCOLLUM. '6. Heating apparatus of the class described, LYNN A. WILLIAMS, JR.