US3759320A

US3759320A - Coil as mount for associated equipment

Info

Publication number: US3759320A
Application number: US00112329*7A
Authority: US
Inventors: R Bullard
Original assignee: Singer Co
Current assignee: MERCANTILE TEXAS CREDIT Corp; Singer Co; Daikin Applied Americas Inc
Priority date: 1971-02-03
Filing date: 1971-02-03
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18

Abstract

A fin-tube heat exchange coil having heavy gauge plates connected to selected core tubes of a coil so that the plates act as rigid extensions within the centrodial area of a coil. The plates, different than tube sheets, may be used either to orient and mount equipment, for example a motor, in a fixed relation to the coil or to mount and support the coil from its center or ends in a fixed relation to its associated equipment. The fixed mounting relation to the coil can be at all four mounting quadrants, i.e.: top, bottom, front and rear or angled therein.

Description

Unite States atent [1 1 3,759,320 Buiiard Sept. 18, 1973 COIL AS MOUNT FOR ASSOCIATED EQUIPMENT FOREIGN PATENTS OR APPLICATIONS 1,303,675 6/1962 France 165/121 [75] Inventor: Iifissel i fi lafdfwihr n n gfif n 7 W H 7 NC Primary Examiner-Charles J. Myhre r e MA r Assistant Examiner-Theophil W. Streule, Jr, [73] Assgnee' 3,25??? New Attorney-Breen, Williams & Ebs

22 Filed: F353, 1971' 211 Appl. No.: 112,329 57 ABSTRACT [52} U 8 Cl 165/122 A fin-tube heat exchange coil having heavy gauge [51] In. .0. $24}! 3/06 plates connected to selected core tubes of a coil so that [58] Fie'ld 2 162 the plates act as rigid extensions within the centrodial 178 area of a coil. The plates, different than tube sheets, may be used either to orient and mount equipment, for [56] References Cited example a motor, in a fixed relation to the coil or to mount and support the coil from its center or ends in UNITED STATES PATENTS a fixed relation to its associated equipment. The fixed 2,021,356 11935 Forbesm- 165/172 X mounting relation to the coil can be at all four mount 5 $2338 g ing quadrants, i.e,: top, bottom, front and rear or an- 2:346:4l0 4/1944 Ashley et a1. 165/122 x gled 5 Claims, 9 Drawing Figures Patented Sept. 18, 1973 3,759,320

2 Sheets-Sheet l FIG. 1

M. -29 29 1 261 zeal -Z6a. r 26.0

INVENTOR. RUSSELL H. BULLAED COIL AS MOUNT FOR ASSOCIATED EQUIPMENT THE DRAWINGS FIG. 1 is a sectional view taken through a coil-plate assembly embodying the invention.

FIG. 2 is a fragmentary sectional view on line 2-2 in FIG. 1.

FIG. 3 is a sectional view taken through a certain aircooled refrigerant condenser embodying the invention.

FIGS. 4, 5 and 6 are sectional views taken through an air conditioner embodying the invention.

FIGS. 7 and 8 illustrate the invention applied to a downflow he'ater.

FIG. 9 illustrates the invention applied to a baseboard heater.

FIG. 1 shows a heat exchange coil comprising a number of tubes 10 extending transversely through spacedparallel heat transfer fins 12. One of the tubes has an open end 14 for connection with a source of hot fluid or cold fluid (hot water, cold water, or vaporizable refrigerant or steam) so that the fluid flows leftwardly through that tube to a U-bend 16, and thence rightwardly through the lower tube 10 to another U-bend 18. The complete coil may have different numbers of tubes 10, for example as little as twenty or as many as one hundred, depending on such factors as tube fluid supply temperature and pressure, air velocity across the fins, permissible pressure drop in the air stream, required temperature change in the air stream, and volumetric flow within the tubes. The heat exchange tubes 10 are usually arranged in rows, for example as little as one row or many as 8 rows. FIG. 1 shows a coil having two rows of tubes extending transverse to the direction of air flow (indicated by numeral In manufacture of the illustrated heat exchange coil the fins 12 are arranged in a loose stack with their collars 22 enjoying slip fits on the tubes 10. Thereafter, rod-like mandrels (not shown) are moved through tubes 10 to expand the tubes ouwardly into mechanical bond connections with the inner surfaces of the collars, thereby rigidly locking the fins onto the tubes and forming a cross flow heat transfer path between the fluid flowing within the tubes and the air passing across the fin surfaces. After the fins have thus been mounted on the tubes the various U-bends l6 and 18 are connected to the tubes, as by soldering or other means.

FIG. 1 shows relatively heavy gauge fins spaced apart by a distance 24 that is about three times the fin thickness. Actually the fin thickness and fin spacing somewhat less than as shown in FIG. 1. Commonly the fins are formed of aluminum or copper material having a thickness of about 0.008 inches; the fin spacing usually measures between about 6 to 18 fins per linear inch of tube length. The fin spacing is therefore on the order of about 0.10 inches (or in the neighborhood of IO times the fin thickness).

In practice of the present invention the spaces between selected ones of fins 12 are occupied by heavy gauge plates 26. These plates are secured to their supporting tubes in like manner as employed in the mechanical bonding of the tubes to the fins. These plates can be used to connect coil 8 to an associated non-rigid element such as a housing wall, fan motor, filter support, etc. In an alternate manner, the coil can be the non-supported assembly which is in turn secured to a rigidly fixed equipment member by means of the heavy gauge plates 26. The rightmost plate 26 has circular openings encircling selected ones of the fine collars 22; the leftmost plates 26 has circular openings encircling and directly engaging selected ones of tubes 10. Either or both plate arrangements or a series of such plate arrangements can be used in practice of the invention. However, the leftmost arrangement is preferred because it does allow for a four point leveling alignment.

During the coil manufacturing stage plates 26 are positioned within the loose stack of fins 12. With the plates 26 thus positioned, the mandrels are run through tubes 10, thereby expanding the tubes into bonded connections with the collars and plates 26; this action rigidly locks plates 26 and the heat exchange coil thus joined together as a single unitary structure.

As shown in FIG. 1, the rightward plate 26 has a thickness corresponding to the fin spacing 24; the left most plate is slightly thicker than the fin spacing. Preferably the plates 26 are at least about 0.1 inch thick such that the plates act as rigid extensions of the coil. Fins 12 are shown flat but in practice they usually have tiny preformed corrugations extending therein for producing turbulence in the air stream 20. Such turbulence tends to improve heat transfer on the air side of the coil.

FIG. 3 illustrates the invention applied to a refrigerant condenser of the air-cooled type. As shown in FIG. 3, the condenser comprises a fin-tube heat exchange coil 8 having plate type fins 12 csrried on refrigerant condenser tubes 10. Adjacent ones of the tubes are interconnected by U-bends 16 and 18.

Coil 8 is positioned within a rectangular housing 30 having a right end wall 32, a left end wall 34, and the two additional interconnecting side walls, not numbered. Air is moved upwardly through the coil 8 fins by a propeller fan 36 carried on the shaft 38 of an electric motor 40. Fan 36 is positioned within a venturi inlet 42 carried on the housing bottom wall 44 such that rotachamber 48, and thence through the fin spaces.

The two left corners of condenser housing 30 are equipped with depending legs 50 for spacing wall 44 above the concrete slab or building roof surface 52. Preferably the right end portion of the housing includes a partition 54 which forms a compartment 56 for a refrigerant compressor 58; a removable closure 60 closes compartment 56 except when it is necessary to service the compressor or other components housed in compartment 56. Refrigerant tubing, not shown, interconnects compressor 58 to condenser tubes 10 and to remotely located refrigerant evaporator, not shown. Commonly the evaporator is positioned within an air duct supplying air to the home, office, school room, etc. requiring cool air. Evaporated refrigerant is returned from the evaporator to compressor 58 where it is compressed, and in the process heated to an elevated temperature, for example 200 F. High Pressure, high temperature refrigerant gas is circulated through the tubes of condenser 8 where it is condenser to a lower temperature, for example F, by the upflowing air propelled across the fins by propeller fan 36.

As clearly shown in FIG. 3, fan motor 40 is mounted between two plates 26a which extend from the surface of the condenser coil 8. These plates 26a are similar to the afore-mentioned plates 26 in that they include circular openings which tightly encircle selected one of the tubes 10. Lower end portions 27 of the plates form flanges which can be used to receive bolts, not shown, going through a mounting flange on motor ll). With this arrangement the motor 40 is centered and rigidly mounted with respect to the coil 3, thereby using the strength of rigidity of the coil for support and its mass to absorb mechanical vibration of the motor. Plates 26a are near the fan axis where air flow is characteristically minimal; therefore the plates do not interfere with air flow. If necessary, air flow openings may be formed in plates 26a to allow for the heat conducted by the brackets to transfer to the surrounding air.

Preferably each plate 26a is of sufficient dimension perpendicular to the axes of the tubes as to encircle more than one of the tubes ill. For example, it is preferred that each plate 26a have five or more circular openingstherethrough for locking each plate to a similar number of tubes 1%. This multi-tube connection improves the rigidity and vibration resistance of the assembly, both parallel to the plane of the fins and perpendicular to the plane of the tubes. If necessary, each plate 26a can be equipped with wing-type flanges 41 to further improve the rigidity, although it is believed that in most cases the strength characteristics offered by the heavy plates and by tubes are sufficient for imparting mounting rigidity to the motor. Fins 12 are very thin gauge, but the multiplicity of fins, (numbering upwards of 200 fins) provides crosswise rigidity between tubes 10. Therefore, as in this case, the fin-tube coil assembly offers a very rigid and centered base for motor 46.

Preferably coil 8 is mounted in condenser housing 30 by means of a coil frame 2617 connected to the coil as part of the coil-manufacturing process described in connection with FIG. 1. As shown in FIG. 3, such a coil frame 261; includes a wall portion 26c which extends laterally beyond the tin areas in the form of tube sheets for, among other prior art reasons, prevention of upward air flow through the spaces occupied by

U-bends

16 or 18. Each tube sheet further includes an upwardly extending flange 29 which can be bolted, spot welded, or otherwise connected to the

condenser housing walls

32 and 34. The illustrated arrangement uses the strength of coil 8 to rigidify the housing, thereby permitting the housing to be formed of lighter gauge material or otherwise minimizing the need for separate reinforcement ribs, angle irons, etc.

In the FIG. 3 arrangement motor 40 enjoys a precise and rigid relationship with coil 8, but there is a possibility of misalignment between propeller fan 36 and inlet venturi 42. Therefore venturi 42 is preferably formed separately from housing bottom wall 44. The venturi 42 may be connected to wall 44 by peripheral bolts going through oversize holes in the respective elements, such that the bolts can be loosened to permit such lateral adjustment of the venturi as will enable it to have the desired clearance with respect to the tips of the fan blades. Secondary adjustment, in the form of motor mounting slots on the mounting plates 26a, are also usable for alignment purposes.

FIG. 4 illustrates in a semi-schematic manner a ceiling type air conditioner which includes a finned heat exchange coil 8 having fluid tubes 10 and plate fin 12. Coil 8 is positioned within a housing which includes a top wall 60, a left wall 62, and a right wall 64. The housing further includes a bottom wall 66 and two

side walls

68 and 70. A centrifugal fan 72 is located within the housing to draw air through an inlet opening 63, and thence through the fin spaces into a plenum chamber 73. A double inlet fan wheel, not shown, is rotatably positioned within the scroll housing of the fan in direct driven connection with an electric motor suitably mounted on the fan housing. Operation of motor '75 causes conditioned air to be discharged through an exit opening in housing wall 64.

Preferably fan housing 72 utilizes coil 8 as a mounting structure. As shown in FIG. 6, the fan housing is suspended between this inventions two heavy gauge plates 26d which form part of a channel element 26e. Plates 26d are preformed with four circular openings, penetrating inwards into the coil core to multi-row depth, which tightly encircle the four uppermost tubes 10 in the heat exchange unit, such that element 26c is rigidly locked to the heat exchange coil. Screws, bolts, etc. may be used to suspend fan housing 72 between the two plates 26d.

The FIG. 4 coil is preferably formed with tube sheets 26b which are rigidly locked to fluid tubes 10 as part of the coil-manufacturing operation. These tube sheets 26b preferably extend the full height of the coil to form baffle surfaces for, among other prior art reasons, preventing any by-pass of air around the fins, as through the spaces 73 occupied by the U-bends. Flanges 29 on the heavy gauge mounting plates can be used to connect the

housing side walls

68 and 70 to the rigid coil assembly.

Advantageously,

walls

66, 68 and 70 may be formed as a U-shaped member, as shown in FIG. 5; with such an arrangement screws, etc. may be extended through the mounting plates flanges 29 to mount the entire U- shaped wall structure onto coil 8. Top wall 60 and end walls 62 and 64 may also be formed as a U-shaped unit, so that screws, etc. may be extended through channel 26e and wall 60 to connect the second U-shaped wall structure to the coil unit.

The structure of FIGS. 4 through 6 uses coil 8 as a central rigid structure for mounting fan 72 as well as the

various housing walls

60, 62, 64, 66, 68 and 70 or the converse. It is believed that such an arrangement has desirable strength features not possessed by arrangements wherein the strength of the coil is not as effectively used.

FIGS. 7 and 8 illustrate the invention as applied to a heater of the downflow delivery type. The illustrated heater comprises a square of circular top wall and a similarly dimensioned bottom wall 82. The peripheral space between these two walls is occupied by a heat exchange coil 8 which is of endless construction, either square or cylindrical, in accordance with the configuration of

walls

80 and 82.

Depending from wall 80 is a motor mount bracket 84 having suitable openings for mounting an electric motor 86. A propeller fan 36 is carried on the motor shaft 38 to produce a downflow of heated air from the central plenum chamber 88. Fan operation causes air to be drawn from peripheral space through the fins 12 of coil 3, into plenum 88, and thence through the venturi 42 downwardly into the room or space requiring heat.

In the FIG. 7

heater walls

80 and 82 are locked to the annular coil 8 by means of three or more plates 26f spaced around the heater periphery. As shown in FIG. 8, a representative plate 2of includes circular openings which tightly encircle the fin collars, thereby mechanically locking the plate to the fluid tubes 10. As in the previously described constructions, the locking operation is achieved by outward radial expansions of tubes during the coil manufacturing process.

Each plate 26f may be provided with tab-

like extensions

26g and 26h for connecting

respective walls

80 and 82 to the coil assembly. Initially each tab 26h is bent laterally as shown in FIG. 8. Thereafter the

respective wall

80 or 82 is positioned against respective ones of the tabs 26h, with the other tab 26g extending through a slot or opening in the

respective wall

80 or 82. Each tab 26g is then turned laterally to lock the

respective wall

80 or 82 onto the coil unit. Any desired number of mounting pates 26fcan be used, depending on the weight and size of the heater, and the gauge of

walls

80 and 82. The various plates 26f serve to rigidly lock the

housing walls

86 and 82 to the coil, thereby taking advantage of the structural strength of the coil for reinforcing the heater walls.

FIG. 9 illustrates the invention as applied to a baseboard heater. As shown in FIG. 9, the baseboard heater comprises a heat exchange unit 8 having hot water tubes 10 connected with heat transfer fins 12, as by means of fin collars of the type shown in FIG. 1. Heat exchange unit 8 is elongated in directions perpendicular to the plane of the paper, as for example a distance of eight or more feet. At spaced points along its length the heat exchange unit is provided with heavy gauge plates 26L. Each plate 26L may be connected to the heat exchange unit in the manner of plates 26 shown in FIG. 1; plates 26L thus form rigid extensions of the heat exchange unit. The illustrated plate 26L is provided with

flanges

26m, 26n and 26p. Flanges 26m and 26n may be connected to a main sheet metal wall structure 92 comprising a bottom wall 93, a rear wall 94 and a top wall 95. Each flange 26p may be removably associated with an elongated front wall 96, as by means of screws, or clips, not shown.

The baseboard heating unit is in practice positioned at the joint between the floor and side wall of a room, so that wall 93 rests on the floor, and wall 94 is positioned against the building side wall. A complete heating system is built up at the jobsite by connecting individual ones of the baseboard units together. In use of the completed system hot water is pumped through tubes 10 to heat the fins 12. Cold air adjacent the floor of the room is caused to flow upwardly through the fin spaces by convection, and to be discharged into the room through a slot-like opening 97.

It will be seen that plates 26L serve as rigidifying connections between the heat exchange unit 8 and the relatively thin nomrigid members 92 an 96. Flanges 26m and 26n also can be used as rigid elements for connecting the coil unit to the building structure.

This invention is believed useful as a low cost method of accurately orienting and connecting a rigid tube-fin heat exchange coil to non-rigid or vibration-prone structures associated with the coil. The drawings show such non-rigid, and/or vibration-prone structures as fan motors, fan housings, and air conditioner housings; other structures might be filter racks, burners, gasliquid contact media, spray nozzles, compressors and receivers.

In use of the invention the mounting plates 26 are in each instance rigidly locked to the tubes of the heat exchange coil to take advantage of the structural strength of the coil. Preferably each plate 26 has more than one tube-encircling connection so that each plate assumes the strength of a multiplicity of tubes. Preferably each plate is a heavy gauge plate.

I claim:

1. In combination: a rigid fin-tube heat exchange coil; at least one non-rigid element associated with said coil; and at least one heavy gauge plate extending from the coil in supporting relation to the associated element whereby said element takes on the rigidity of the coil; said plate being positioned between adjacent fins and having openings therein to receive selected tubes mechanically to join the plate to the coil, the fins being plate-type fins extending transversely across the tubes; said fins having tube-encircling collars extending through said openings in the plate; and the fin collars having tight fits within the plate openings mechanically to lock the tube, fin and plate together.

2. The combination of claim 1 wherein the plate thickness is approximately the same as the fin spacing.

3. The combination of claim 2 wherein the plate thickness is appreciably greater than the fin thickness.

4. The combination of claim 1 wherein the associated element is a motor fan assembly.

5. The combination of claim 1 wherein the tubes are expanded into bonded connection with the tube encircling fin collars and plates.