US2290978A

US2290978A - Warm air furnace

Info

Publication number: US2290978A
Application number: US323909A
Authority: US
Inventors: Allen P Livar
Original assignee: Chrysler Corp
Current assignee: Old Carco LLC
Priority date: 1940-03-14
Filing date: 1940-03-14
Publication date: 1942-07-28
Anticipated expiration: 1959-07-28

Description

July 2s, 1942.` AgF. LNAR 2,290,978

WARM'AIR FURNAQE Filed March 14, 1940 3 .Sheets-Sheet 1 [N VENTOR July 28, 1942. A, P VAR l 2,290,978

' WARMAIR FURNACE Filed March 14, 1940 3 Sheets-Sheet 2 m [N VEN T 0R BY `FZ-lay:

fm, fag? 25 M A TT ORNE Y v July 1942. *A lP LIVAR A 2,290,978 w-ARMv AIR FURNACE FiledMarch 14, 1940 :s sheets-sheet s f INVENTOR HZZe/f P .WWU M, W

Patented July 28, 1942 WARM AIR FURNACE llen P. Livar, Dayton, Ohio, assigner to Chrysler Corporation, Detroit, Mich., a corporation of Delaware Application March 14, 1940, Serial No. 323,909

12 Claims.

The present invention pertains to the construction of a warm air furnace, with particular regard to the provision of means for mounting and aligning the heavy heat exchanging surfaces of the furnace in the jacket of the furnace. The invention is of utmost utility in the construction of a gas-red furnace since the nature of the nue gases from gas flames is such as to make it advisable to use cast iron heating sections which are less subject to corrosion than Sheet metal heating sections, although it will be perfectly obvious that other types of fuels may be used in a furnace of the present invention and that other metals than cast iron may be used in the heat exchanging surfaces.

The principal object of the present invention is to devise heat exchanging means of singular efficiency in order that the weight of the heat exchanging means may be reduced to a minimum in spite of the fact that it is made of a heavy metal 'such as cast iron. Another object of the present invention is to provide means to support and align a heavy heat exchanger assembly at such a height above the oor as to permit the introduction of air from a blower means beneath the heat exchanger assembly. Another object of the present invention is to devise the heat exchanger assembly so as to provide the Vsame with a curved bottom wall such that the air introduced beneath the heat exchanger assembly will be evenly divided around the bottom of the assembly.

In connection with the provision of means for supporting and aligning a heat exchanger assembly having a curved bottom wall, it is an object of the present invention to provide supporting and aligning means which automatically align the heat exchanger assembly with the remainder of the furnace'so that expensive jigs or iixtures need not be provided for the purpose of assemblying the furnace. It is an object of the invention to form such supporting and aligning means so as to be easily assembled without the aid of expensive jigs or fixtures for themanufacture of the supporting and aligningimeans.

It is a further object of the present invention to form the supporting and aligning means as a unitary structure having associated therewith rigid members serving as alignment guides and tip-limiting abutments, between which a portion of the heat exchanger assembly may be placed and instantaneously aligned in a vertical direcM tion, and which also act to prevent tipping of the heat exchanger assembly beyond a very slight degree from vertical during the life of the furnace. Y

These and other objects and advantages of the present invention should be readily apparent from the following specification taken in connection with the accompanying drawings wherein like numerals refer to like parts throughout.

In the drawings, Fig.'1 discloses a vertical section through the front end of the furnace of the present invention, taken substantially along line l-l of Fig. 2;

Fig. 2 is a vertical section taken at right angles tothe plane of Fig. 1 and substantially along line 2 2 of Fig. 1, the figure being on a slightly reduced scale;

Fig. '3 is a vertical section of the rear end of the furnace, taken substantially along line 3 3 of FigZ; and,

Fig. 4 is a View, substantially similar to Fig. 1, of a modified form of furnace having a plurality of heat exchanger assemblies mounted therein.

Referring to Figs. 1, 2, and 3, there is disclosed a furnace vcomprising an enclosing jacket 20, and front and rear, vertical partitions 2l and 22, respectively, dividing the interior of the furnace into an air entrance compartment 23 at the rear of the furnace, a heat exchanger compartment 24 in the intermediate portion of the furnace, and a front compartment 25. Air is admitted to the entrance compartment 23 through an opening 26 in the top wall of the jacket and drawn through filters 21' by blower means 28, mounted in the bottom of the compartment on legs 29 provided with resilient feet 30, and driven by a motor 3|. The air is forced into the lower portion of the heat exchanger compartment 24 through the blower outlet 35 and between the rear legs 36 and front legs 31 of the sup-porting and aligning means 40. The air flows upward through thecompartment 24 in contact 'with the surfaces of the heat exchanger assembly 4l and leaves the furnace jacket through an opening 42 in the top wall of the furnace. The openings 26 and 42 are preferably flanged for connection of the jacket to duct work.

The heat exchanger assembly lll preferably comprises a plurality of identical, substantially symmetrical with respect to the vertical center plane; sections l5 which are provided with complementary internal openings, forming passages for the gases of combustion, and complementary external surfaces, forming passages for the flow of air across the surfaces heated by the gases of combustion. Each section includes walls 46 rising from a lower rebox portion 47 having a curved bottom wall 48, In the central upper portion of each wall 45 there is provided a protruding ange 49, the flanges of adjacent sections forming, together with the sealing rings 50, a gas passage in communication with the spaces between the walls 48 and the interiors of the rebox portions and with the interior of a stack con-Y nector 5| extending through the partition 22, into the compartment 23 and laterally through a side wall of the jacket. rIhe stack connector 5| is fastened to the rear opening of the rear section 45 by tie-rods 52 extending through the communicating openings and a cap 53 sealing the front opening of the front section 45. The re box portions 41 are provided with flanges which, together with sealing bands 55, rear plate 56, and iront plate 51 form a firebox into whichlthe gas burner 58 or other name-producing means is introduced.

The upper portions of the sections 45 are preferably wider than the firebox portions so as more completely to ll the space between the side walls of the jacket, andbafes. extendinginward'from the side walls of the jacketidirect the air rising around the lower portions of the assembly into the spaces between the walls 450i adjacent sections. The walls 4B arepreferably provided with a plurality of integral'heatexchanging pins 6|, preferably arranged in staggered rows so as to cause the air to follow tortuous courses in contact with the pins and the walls, as shown by full-line arrows. Preferably those of the pins in the centralportion of the walls are matched by integral baffle rods 62 extending between the walls 46 of each section so as to cause the gases of combustion to impart more heat to the walls and pins 6|. Also, it is preferable that an arcuate bale 53 extendbetween the walls 43 substantially in line with the lower parts of flanges 4S so as to cause the flue gases to rise into the upper, outer corners of the heat exchangers beiore travelling horizontally into the stack connector 5|, as shown by broken-line arrows.

The plates 56 and 51 are joined by tie-rods 65, 66, 61, and 68, at least two of which, tie-rods 66 and 58, extend horizontally and externally of the assembly above the curved bottom walls 48. Mounting bolts -18 and 1|, extending forward from plate 51, support a mounting plate 12 which is sealed to a flange 13 extending forward `from platel 51 through partition 2|, and which provides a support for the venturi 15'of the gas burner, the pilot tube 16, an inspection door 11, vand other devices commonly associated with a gas burner. The tops of each section 45 may be provided with lug's 8! between which may be placed a humidifier pan 8|. vSuitable controls for the furnace (not shown) may be mounted in the compartment 25 and the jacket may be provided with access doors (not shown) wherever desired.

The heat exchanger assembly is obviously too heavy to be supported by the partitions 2| and 22 unless such partitions were made of such heavy materials as to be impractical. Accordingly, the supporting means 48 is Vdesigned to carry the entire -weight of the heat exchanger assembly 4|, the heat exchanger assembly being mounted and aligned in the supporting means 4|) and the jacket then placed about the combined units. The jacket preferablyrests upon the floor and preferably has very little contact with the heat exchanger assembly so that it may be shifted slightly after assembly.

The supporting and aligning means 4|) comprises the legs 36 and 31, previously described, lower, horizontal braces 85 connecting the bottoms of legs 35, and connecting the bottoms of legs 31, and upper braces 81 and 88 running longitudinally of the assembly between the front and rear legs and connected thereto by gusset plates 89. The legs extend upward above the longitudinal braces 81 and 88, and vertical plates and 9| at the front and rear, respectively, are welded to the upright extensions thereof. Each plate is provided with a V-shaped upper edge adapted to cradle a curved bottom wall 48 of `one of the sections 45, with the sides of the V-shaped edges tangentially in contact with the .curved bottom wall. The angularity of the V is preferably such as to make the points of contact "equally spacedhfrom the center plane of the heat exchanger assembly so as to give some lateral support in addition to supporting the entire weight of theheat exchanger assembly, and so as to cause the heat exchanger assembly to slide into horizontal alignment when rested thereon.

The four legs continue on beyond the curved bottom Ywall and terminate. at such heights with respectY tothe tangential points-of contact of the curvedzbottom wall and the V-shaped edge of plates.9|l.and :9| as to be beneath `andf closely adjacent, b'ut'preferably not touching, Ythe rtie-rods Strand' 68 adjacent'the Vears through which the tie-'rods pass.

This :construction permits theV manufacture of a heat exchanger assembly having `somewhat loose'tolerances and the manufacture of a supporting Vstructure and jacket' having equally' loose tolerances. The V-shaped edgesof platesv 90 and 9| are cut fairlyaccurately so .thatif the bottom wall of the section were :accurately .machined the heat exchanger assembly wouldalign itself in `,the supporting cradle. However, 'since cast iron is hardly ever true, .the Arigid,'upper ends of the legs'of the .supporting structure'serve as aligninglixtures which .the assembly crew may observe to '.seethat the heat exchangerfassembly is vertically aligned. 'No fastening means are necessary foreld assembly since the Lheat exchanger assembly isicradled inthe supporting: and aligning structure, :and the tops ofthe legs prevent serious tipping Vof' the heat :exchanger assembly by abutting thetie-rods inthe event that the heat exchanger'assembly tips toward Vone side or the other.

, Fig. 4 discloses'a .modification/of the present invention' whereinl av plurality of heat exchanger assemblies 4| are cradled side by side in a modied supporting and .aligning structure 40'. In this instance the supportingand aligning structure comprises a structure including vertical, front legs 31', vertical, rear legs (not shown) and cross braces as indicated. 'A modified. vertical plate90 isprovided with a plurality of equal, V-shaped notches in its upper edges adapted to cradle, space, and align theheat exchanger sections. The plate "90' is welded to vsubstantially vertical, rigid 'members |00 and IDI forming a pair of aligningand tip-limiting abutments for one heat exchanger, and rigid members |82 and |83 'forming 'a' second 'pair for the 'other heat exchanger assembly. Plate 90 may be matched by Va similar rear plate (not shown)v and the rigid members maybe matched by a similar rear member (not shown). It is also preferable that the baiiies 80, mounted on the jacket walls, be supplemented by a central-baule 60 adapted to direct air from the center toward the sides of the compartmentl 24.

It is obvious from inspection of Fig. 1 thatlthe present construction permits of limitless alteration in capacity Without material change in the principal parts. For example, a single heat exchanger section 45 may be used to form a Very small furnace by mounting plates 56 and 51 on opposite flanges of the section and by attaching stack connector l to the rear of the single section. Similarly, heat exchanger assemblies comprising any other reasonable number of sections 45 may be built up as shown. In'the case of a single-section heat exchanger assembly it would probably be sufficient to include only the front supporting plate 90 and the extensions of the front legs 31, or the rear supporting plate 9| and the extensions of rear legs 36, permitting the opposite end of the assembly to rest upon a simple, supporting member on the frame 40. Similarly, if a greater number of sections were built up to form a longer heat exchanger assembly, a greater number of supporting plates and extensions than, shown might be used in the supporting assembly. As seen in Fig. 4 a plurality of heat exchanger assemblies may be utilized so as to limit the length of the furnace to a reasonable limit by using a plurality of heat exchanger assemblies in side by side relationship in a Wider furnace, in which case it may be preferable so to space the supporting structure legs as to cause them to serve as braces for the side walls of the jacket.

In the foregoing specification and in the following claims I use the term cast iron to indicate the preferred material for construction of the heat exchanger sections. It is obvious that any material, such as Welded steel plates, may be substituted therefor Without the exercise of invention; and the use of the term cast iron is only meant to emphasize the singular utility of the invention in connection With a heat exchanger assembly of a material having relatively great Weight.

It is also obvious that the present invention could be adapted to the burning of other types of fuels, the disclosure being of agas-iired furnace since the use of cast iron or heavy steel plate is particularly associated with the use of gas as a fuel. Other types of burner may be associated with the structure Without the exercise of invention.

Having described preferred embodiments of the invention it should now be apparent to those skilled in the art that the same permits of modications in arrangement and detail. All such modications as come within the scope of the following claims are considered to be part of my invention.

I claim:

1. A Warm air furnace comprising a heat exchanger assembly, said heat exchanger assembly being substantially symmetrical vvith respect to a vertical, longitudinal plane, and including an externally curved bottom Wall substantially symmetrical to said plane, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a vertical plate having a V-shaped notch in its upper edge to cradle the curved bottom wall of vsaid heat exchanger assembly With the sides of the notch contacting said curved bottom wall substantially tangentially at points equally spaced from said plane.

2. A warm air furnace comprising a heat exchanger assembly, said heat exchanger assembly being substantially symmetrical with respect to a vertical, longitudinal plane, and including an externally curved bottom Wall substantially symmetrical to said plane, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a plurality of vertical plates each having a V-shaped notch in its upper edge to cradle the curved bottom wall of said heat exchanger assembly With the sides of the notch tangentially contacting said curved bottom Wall at points equally spaced from said plane.

3. A Warm air furnace comprising a heat exchanger assembly, said heat exchanger assembly being substantially symmetrical with respect to a vertical, longitudinal plane, and including an externally curved bottom Wall substantially symmetrical to said plane, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a vertical plate having a V-shaped notch in its upper edge to cradle the curved bottom wall of said heat exchanger assembly With the sides of the notch contacting said curved bottom Wall substantialllr tangentially at points equally spaced from said plane, and a pair of upright, rigid members each extending above a point of contact of said plate and bottom Wall and terminating adjacent a portion of said assembly to serve as a vertical alignment fixture and tip-limiting abutment.

4. A Warm air furnace comprising a heat exchanger assembly, said heat exchanger assembly being substantially symmetrical with respect to a vertical, longitudinal plane, and including an externally curved bottom Wall substantially symmetrical to said plane, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a plurality of vertical plates each having a V-shaped notch in its upper edge to cradle the curved bottom Wall of said heat exchanger assembly with the sides of the notch tangentially contacting said curved bottom Wall at points equally spaced from said plane, and a plurality of pairs of upright, rigid members, each pair of members extending above the points of contact of one of said plates and the bottom Wall contiguous thereto and terminating adjacent portions of said assembly to serve as vertical alignment fixtures and tip-limiting abutments.

5. A Warm air furnace comprising a heat exchanger assembly, said heat exchanger assembly being substantially symmetrical With respect to a vertical, longitudinal plane, and including an externally curved bottom Wall substantially symmetrical to said plane and external abutment members above said curved bottom Wall on each side of the heat exchanger assembly, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a vertical plate having a V-shaped notch in its upper edge to cradle the curved bottom Wall of said heat exchanger assembly With the sides of the notch contacting said curved bottom Wall substantially tangentially at equally spaced lpoints from said plane, and a pair of upright,

rigid members each extending above a point of contact of said plate and bottom Wall and terminating closely adjacent and below one of said abutment members to serve as a vertical align- -ment fixture and to coact with said abutment "bly being substantially symmetrical with respect to a vertical, longitudinal plane, and including an externallycurved bottom wall. substantially symmetrical to said plane and external abutment members above said curved bottom Wall on each side of theheat exchanger'assembly, and means to support and align said heat exchanger assembly inthe furnace comprising a frame including a pluralityof vertical plates each having a V-shaped notch in its upper edge to cradle the curved bottom Wall of said heat exchanger assembly vvith the sides of the notch contacting saidcurved bottom wall substantially tangentially at equally spaced points from said plane, and a plurality of pairs of upright, rigid members, each pair of members extending above the points of contact of one of said plates and the bottom wall contiguousl thereto and terminating closely adjacent and below said abutment members to serve as vertical alignment fixtures and to coact with said abutment members to limit tipping movement of said heat exchanger assembly.

7. A warm air furnace comprising a heavy heat exchanger assemblyy having provision for the transfer of heat from internally combusted fuel to air in contact withftlie external surface thereof and a curvedfbottom wall lying on an arc about a point along the vertical centerline of said assembly, said assembly being of substantially equal proportions on each side of said vertical centerline so that the center of. gravity thereof lies along said vertical centerline, and means to support and align saidheat exchanger assembly in the furnace comprising a frame including a vertical plate having a V -shaped upper edge adapted to cradle said curved bottom wall with the sides of the V-shaped edge tangentially contacting said curved bottom wall.

8. A warm air. furnace comprising a heavy heat exchanger assembly having provision for the transfer of heat from internally combusted;

fuel to air in contactY with the external surface thereof and aV curved` bottoni wall lying on an arc about a. point along the vertical centerline of said assembly, .saidassembly'being of substantially equal proportions onleach side of said verticalA centerline so thatY the center of gravity4 thereof lies along saidivertical centerline, andmeans to support and align saidY heat exchanger assembly in the furnace comprising a frame including a plurality'of vertical plates each havingV a V-shaped upper edge adapted to cradle saidcurved bottom wall with the sides of the V-shaped.. edge tangentially contact-ing said curved bottom; wall.

9. A Warm air furnace comprising a heavy heatexchanger assembly having provision for the:

transfer of heat from internally combusted fuelto air in contact'with the external surface there; of anda curved bottom wall lying on an arc about` a point along the Vertical centerline of said assembly, said assembly being of substantially equal`- proportions on each side of said vertical centerline so that the center of gravity thereof lies along, said vertical centerline, and means to support andv align said heat exchanger assembly in the furnace comprising a frame including a vertical plate having a V-shaped upper edge adapted to cradle said curved bottom wall with the sides of the V. shaped edge tangentially contacting said curved, bottom Wall, and a pair of upright, rigid members each extending above a point of contact of said.

plate and bottom wall and terminating adjacent a portion ofv said assembly to serve as a verticalV alignment fixture and tip-limiting abutment.

l0, A warm air furnace comprising a heavy heat exchanger assembly having provision for the transfer of` heat from internally combusted fuel to air in contact with the external surface thereof and a curved bottom wall lying on an arc about a point along the vertical centerline of said assembly, said assembly being of substantially equal proportions on each side of said vertical centerline so that the center of gravity thereof lies along said vertical centerline, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a plurality of vertical plates each having a` V-shaped upper edge adapted to cradle said curved bottom wall with the sides of the V-shaped edge tangentially contacting said curved bottom wall, anda plurality of pairs of upright, rigid members, each pair of members extending above the points of contact of one of said plates and the bottom wall contiguous thereto and terminating# adjacent portionsV of said assembly to serve asvertical alignment fixtures and tip-limiting abutments.

l1. A warm air furnace comprising a heavy heat exchanger assembly having provision for the-*transfer of heat from internally combusted fuel to air in contact with the external surface thereof and a curved bottom Wall lying on an arc about a point along the vertical centerline of said assembly, said assembly'being of substantially equal proportions on each side of said vertical centerline so that the center of gravity thereof lies along said vertical centerline, a horizontally extending tie-rod at each side of said heat exchanger and externally thereof, and means to-support and align said heat exchanger 'assemblylin the furnace comprising a frame including aV vertical plate having a `Vshaped upper edge adapted to cradle said curved bottom wall with thesides of the V-shaped edge tangentially contacting said curved bottom wall, and a pair of upright, rigid members each extendingv above a point' of contact of said plateV and bottom Wall and terminatingclosely adjacent and below one of? said tie-rods to serve' as a vertical alignment fixture and to coact with said tie-rod to limit tipping movement of said'heat exchanger assembly.

12. A warm air furnace comprising a heavy heat exchanger assembly having provision for the transfer of heat from internally combusted fuel to air in Ycontact with the external surface thereof and a curved bottom wall-lying on an arc about affpoint along the vertical centerline ofy said assembly, said assembly being of substantially equal proportions on each side of said vertical centerline so that the center of gravity thereof lies along said vertical centerline, a horizontally extending tie-rod at each side of said heat exchanger and externally thereof, and means to support and align said heat exchanger assembly in the furnace comprising a frame including a plurality of vertical plates each having a Vshaped upper edge adapted to cradle said curved bottom wall with the sides of the V-shaped edge tangentially contacting said curved bottom wall and a plu-4 rality of pairsof upright, rigid members, each pair, of members extending above the points of contact of one of said plates and the bottom wall contiguous thereto and terminating closely. adjacent and below said tie-rods to serve as vertical alignment fixtures and to coact with said tierods to limit tipping movement of said heat exchanger assembly.

- ALLENY P. LIVAR.