US2760726A

US2760726A - Combination radiant and convection heating system

Info

Publication number: US2760726A
Application number: US460632A
Authority: US
Inventors: William W Parks; William R Peterson
Original assignee: Vapor Heating Corp
Current assignee: Vapor Heating Corp
Priority date: 1954-10-06
Filing date: 1954-10-06
Publication date: 1956-08-28
Anticipated expiration: 1973-08-28

Description

Aug. 28, 1956 w. w. PARKS ETAL 2,760,726

COMBINATION RADIANT AND CONVECTION HEATING SYSTEM Filed Oct. 6, 1954 3 Sheets-Sheet 1 BLOWER {1 FAN Q ClECULAT/NG PUMP az s 6 5:17:51 SW. 78 5;

igfi 7% T 7. INVENTORS 1 M. WILLIAM W. PARKS l WILLIAM l2. PETERSON I 7/MWW Aug. 28, 1956 w. w. PARKS ET AL 7 2,760,726

COMBINATION RADIANT AND CONVECTION HEATING SYSTEM Filed Oct. 6, 1954 a Sheds-Sheet 2 INVENTORS WlLLrAM W. PARKS WILLIAM l2. PETERSON 6 y/flwm W4. W

ATTY.

Aug. 28, 1956 w. w. PARKS ET AL COMBINATION RADIANT AND CONVECTION HEATING SYSTEM Filed Oct. 6, 1954 3 Sheets-Sheet 5 3 6 3 3| A?! 7 5 A M p /HW 1 1 I 3 9 a i 3 5 a a z a A 1 A i 7 Ill/ M w s M Tm. in W wwn M M 7- M M W J fifl WW7 B n00, ran/"1111111111111 COWINATION RADIANT AND CONVECTION HEATING SYSTEM William W. Parks, Oak Park, and William R. Peterson, Skokie, Ill, assignors to Vapor Heating Corporation, Chicago, 11L, a corporation of Delaware Application October 6, 1954, Serial No. 460,632

11 Claims. (Cl. 23743) The present invention relates to a combination radiant and convection heating system. It has been designed for use primarily in connection with the heating of buses, house trailers or other road vehicles. The system is, however, by suitable modification, capable of other uses; for example, the heating of railway passenger cars and other similar vehicles.

Specifically, the invention relates to an improved heating system for road or railway vehicles wherein the heat ing effect obtained within the enclosure to be heated is partly the result of heat radiation from the main floor of the vehicle and partly the result of heat convection by virtue of the forced passage of air into contact with the heated floor surfaces and the direction of the thus heated air into the enclosure at suitable locations through passages provided for this purpose.

Briefly, the invention contemplates the provision of an interlocking sectional floor structure proper which, when placed in position on the sub-floor, provides a comparuncnted space therebeneath. The various floor sections are made of high heat conductive metal and each section is formed with an open trough portion that extends transversely of the vehicle. The trough portions extend in spaced parallelism in such a manner that, after the floor has been installed on the sub-floor supporting surface, a continuous heating coil may be placed in serpentine fashion within the troughs and connected to a source of heating media; for example, heated liquid or steam. The open troughs with the heating coil disposed therein are closed by cover plates which, together with the floor sections, form a continuous upper plane floor surface. The underneath convex surface of the trough portion of each metal floor section extends from wall to wall through its respective compartment and presents a relatively larg surface area so that air issuing from a central longitudinal manifold conduit, common to and in communication with the various compartments, may pass beneath this heat radiating surface and absorb heat therefrom. The thus heated air divides and passes laterally in opposite directions into the hollow wall structures of the vehicle from whence it issues through suitable grilles into the interior passenger compartment. The heating system further includes a heater and a circulating pump for the heated liquid and a blower for forcing air through the passages provided for it, together with suitable thermostatically controlled means whereby uniform temperature conditions may be maintained throughout the enclosure for maximum occupant comfort.

A trailer coach or other small vehicle is difficult to heat satisfactorily by radiant means :alone because of the disproportionate area of the floor and side walls relative to the size of the enclosure. In such case there is a pronounced tendency to overheat localized areas of the heat radiant surfaces and thereby provide hot spots at localized areas. it is, therefore, a principal object of the present invention to prevent the overheating of localized areas of the heat radiating surfaces by circulating air in contact 'nited States Patent with said surfaces so as to absorb heat therefrom, the heated air being delivered into the enclosure.

The above described construction makes possible the attainment of numerous objects, principal among which is the ease of assembly of the floor structure and the placement of the heating equipment therein, the latter being capable of installation after the floor proper has been laid.

Another object of the invention is the provision of a sectional floor structure which presents a continuous smooth unbroken floor surface beneath which the continuous heating tube or conduit is Widely distributed and effectively embedded, yet in which all portions of the tube are readily accessible for purposes of inspection, replacement or repair without disturbing the individual sections of the flooring.

The invention is illustrated in certain preferred embodiments in the accompanying drawings, wherein:

Fig. 1 is a perspective view, somewhat schematic in its representation, of an enclosed vehicle, for example, a house trailer to which the heating system of the present invention has been applied;

Fig. 2 is an enlarged horizontal sectional view taken through the rear portion of the vehicle immediately above the floor level thereof;

Fig. 3 is a sectional View taken substantially along the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary sectional view taken substantially along the line 44 of Fig. 2;

Fig. 5 is a sectional view similar to Fig. 4 showing one .of the cover plates employed in connection with the invention partially removed;

,Fig. '6 is a fragmentary sectional view similar to Fig. 3 showing a modified form of heated floor structure;

Fig. 7 is a sectional view taken substantially "along the .line 77 of Fig. 6; and

Fig. 8 is a circuit diagram of the heating system.

Referring now to the drawings in detail and particularly to Fig. 1, the heating system of the present invention has been shown as being applied to a house trailer coach it) but it will be understood that the illustration is purely exemplary and the system may, with or without modification, be used for the heating of buses or other road vehi- :cles or rolling stock such as railway passenger cars.

The coach 10, with certain exceptions that will appear presently, is of conventional design and includes a composite floor 11, composite side walls 12 and 13 (Figs. 2 land 3) and front and

rear Walls

14 and 15. The coach further includes a top wall or roof 16 which is preferably of an insulated type and which bears no specific relation to the present heating system other than to complete the trailer enclosure 17 undergoing heating.

As shown in Figs. 2 to 5 inclusive, the composite floor 11 comprises a sub-floor 20 supported from a pair of inturned. flanges 21 provided on :a pair of metal side sills or beams 22 which extend longitudinally of the coach. The sub-floor is preferably composed of suitable insulating material.

The sub-floor 20 is provided with a central longitudinally extending trough 23 therein which is preferably rectangular in cross section and a tubular metal conduit 24 fills the trough coextensively and has its upper surface flush with the upper surface of the sub-floor. The conduit 24 provides an air conduit for distribution of air in a manner that will be made clear presently.

Supported on the sub-floor 2G and terminating short of the two

side Walls

12 and 13 are a plurality of transversely extending interlocking main floor members or channels 25 (Figs. 2, 4, and 5) having depending

side flanges

26 and 27, the inturned ends 28 of which rest upon the sub-floor. The

side flanges

26 and 27 are connected across their tops by surface panels 29 having medial longitudinally extending heat radiating ribs 30 formed thereon and which also function as strengthening members. The side flanges 26 are formed with protuberances 31 which fit into recesses 32 provided in the side flanges 27 immediately below the surface panel 29. Each channel 25 forms, in combination with the sub-floor 20, an inner air space or duct 33. The channels 25 are preferably formed of aluminum on account of the lightness and excellent heat-conducting qualities of the same.

Each of the channel members 25 has formed in its upper surface panel 29 a longitudinally extending trough portion including a trough proper 34 and

horizontal ledge portions

35 and 36 which are offset from the plane of the surface panel 29. The portion 35 merges with an undercut recess 37 adapted to mate with the bevelled edge 38 of an elongated cover plate 39 having a curved underneath surface 40. The cover plate 39 is adapted to have its edgeregions supported upon the upper surface of the

ledge portions

35 and 36 and a series of clamping screws 41 serve to anchor the cover plate 39 in position so as to close the upper side of the trough portion 34.

As shown in Figs. 1 to 3 inclusive, coils of a continuous tubing 42 are arranged within the trough portions 34 of the various channel members 25 in serpentine fashion so that the coil bends 43 project over the ends of the channels as shown in Figs. 1 and 2. The tubing 42 is formed of metal and the walls thereof are relatively thin so that high and rapid heat conductivity through the walls will be attained and also so that slight deformation of the cross sectional shape of the tubing may take place when the cover plates 39 are secured in position over the troughs 34 to force the metal of the tubing into intimate heat-transfer contact with the surrounding metal of the floor assembly.

The

side Walls

12 and 13 are of similar construction and each wall includes an outer panel 44 and an inner panel 4-5 spaced therefrom so as to provide an air space 46 therebetween. The space 46 communicates with the enclosure 17 through suitable grilles 47 preferably situated immediately beneath the sills of the various coach windows 43 (Fig. 1). An elongated blocking strip or seal 50 extends horizontally between each pair of

walls

44, 45 and seals off the upper portion of the space 46 and serves to direct air inwardly to the compartment 17 through the various grilles 47.

As shown in Figs. 2 and 3, the tubular metal conduit 24 is provided with a plurality of openings 51 in the top wall thereof which establishes communication between the interior of the conduit and each of the air spaces or ducts 33. The rear end of the conduit 24 is operatively connected to a conventional air blower or fan 52 (see also Figs. 1 and 8) driven by a motor M1. Air issuing from the fan 52 and entering the conduit 24 is forced under pressure into the various ducts 33 and equal distribution of the volume of air delivered to the ducts may be attained by graduating the size of the ports 51 along the conduit.

The continuous serpentine tubing 42 is connected in and forms an integral part of a closed fluid heating circuit utilizing hot Water or an anti-freeze solution such as ethylene glycol as the heating medium, although other heating media such as steam is contemplated. The heating circuit extends from a suitable heating coil 60 (Fig. 1) through a pipe section 61 leading to a pump 62 driven by a motor M2 and from thence to a T-fitting 63 where the circuit branches into two

loops

64 and 65 having

return lines

66 and 67 respectively leading back to the heating coil 60 through a conduit 68.

A heater 70 is positioned beneath the heating coil 60 and may be supplied with propane, kerosene or other suitable fuel contained within a fuel tank 71. Obviously, any form of heating means may be substituted for that shown, whether electrical or of the fuel burning type.

In the operation of the system, the control mechanism shown in Fig. 8 serves to maintain uniform temperature conditions throughout the enclosure 17 undergoing heating. A thermostat T is positioned within the enclosure at a suitable location and an aquastat A is interposed within the heating fluid line. The thermostat T is provided with a mercury column 72 adapted to bridge a pair of

contacts

73 and 74 when a predetermined maximum temperature is attained within the enclosure. The

contacts

73 and 74 are disposed in an electrical circuit leading from the negative side of a source of current such as an automobile battery, through a current limiting resistor 75, the

contacts

73, 74, the winding 76 of a normally closed solenoid actuated switch Sw to the positive side of the line. The switch Sw is disposed in a circuit extending from the negative side of the line through a safety switch 77 adapted to become open when excessive heat is generated at the burner, the switch Sw, a fuel shut-off solenoid 78 positioned in the fuel line, and the aquastat A to the positive side of the line. The motors M1 and M2 for the pump 62 and fan 52 are disposed in respective circuits which become energized upon closure of a master switch Sm.

To operate the system, the burner 70 is ignited and the master switch Sm is closed and circuits are immediately established through the motors M1 and M2 to operate the pump 62 and fan 52 respectively. A circuit also will exist through the safety switch, fuel solenoid and aquastat as previously described thus maintaining the flame at the burner and a free flow of the heating fluid through the system, while at the same time air is forced into the conduit 24 from the blower fan 52. This air which is forced into the conduit 24 under pressure escapes through the slot 51 and is distributed to the various air ducts 33 near the center thereof from whence it divides and passes laterally in opposite directions along each duct. During such passage of the air along the ducts 33, heat is assimilated by virtue of the intimate contact of the air with the convex surface of the trough portion of the channel member 25. This air may also absorb some heat from the radiating fins 30 which become heated by direct heat conduction from the wall of the tubing 42 through the metal of the channel member 25. Heated air issuing from the ends of the channel members 25 enters the space existing within the

side walls

12 and 13 from whence it issues from the various grilles 47 and enters the passenger compartment 17 where it serves principally to heat the upper regions of the compartment.

Heated air within the ducts 33 applies heat to the portions of the main floor which are too remote from the trough 34 to receive an appreciable amount of heat by direct conduction and the heated surface panels 29 radiates heat into the enclosure where it serves principally to heat the lower regions of the compartment.

When the temperature within the compartment 17 attains a, predetermined maximum, for example 70 F., the

contacts

73 and 74 are bridged by the mercury column 72 of the thermostat T and the coil 76 of the switch Sw becomes energized, thus opening the switch and interrupting the circuit through the fuel solenoid so that the burner becomes shut down. This same circuit is capable of being opened under the control of the aquastat A when the temperature of the heating fluid attains a predetermined maximum. The circuit also will become open when the safety switch opens due to an undue rise of heat at the burner, occasioned, for example, by insufficient fluid in the system. Obviously when the temperature within the enclosure drops below the predetermined maximum, the circuit through switch coil 76 will be broken, thus allowing the switch Sw to close and restore normal operation of the burner.

In Figs. 6 and 7 a slightly modified form of the structural arrangement of the coach floor has been shown although the principles of operation of the heating system remain the same as described in connection with the other form of floor. Here the composite coach side walls consist of an inner wall panel 101, an intermediate panel 102 and an outer panel or skin 103. The space existing between the panels 102 and 103 is filled with a suitable insulating material 104 which may be of the preformed package type and thespace existing between the panels 101 and 102 communicates with the various air ducts 105 provided within a series of main floor channel members 106. At the sides of the coach, longitudinally extending resilient sealing members 110 are supported on the side sills 111 between wooden beams 112 and sill flanges 113. The sub-floor consists of a block of insulating material 114 supported on a plate 115 riveted to the side sills 111. The serpentine conduit 116 which contains the heating fluid, instead of being disposed within a trough on the upper side of the channel members 106 is actually contained within the air ducts 105 and the coil bends 117 are supported on the resilient sealing members 110, as are also the return lines 118 associated with the tubing. The plate 115 is supported on a series of I-beams 119 which, in turn, are carried on transverse structural members 120.

In the construction just described, the wooden beams 112 prevent any direct metal-to-metal contact between the side sills 111 and the metal floor proper. These beams thus serve the dual function 'of structural and insulating members so that no appreciable amount of heat will be lost by conduction through the composite floor structure. above, the heating system operates in substantially the same manner as described in connection with the form of the invention illustrated in Figs. 1 to 5 inclusive.

We claim:

1. In a vehicle construction, a composite floor including a sub-floor and a main floor assembly, said main floor assembly comprising a plurality of generally U-shaped metal channel members each having a surface panel and spaced depending side flanges, said channel members being arranged in contiguity with adjacent side flanges abutting each other and supported on the sub-floor, thus providing in combination with the latter a series of parallel air ducts beneath the respective surface panels, tubing adapted to contain a heating fluid disposed below the level of said surface panels and having straightaway portions ex- Except for the structural dilferences noted tending longitudinally and co-extensively with the respective channel members and arranged to radiate heat through said surface panel into the interior of said vehicle and also radiate heat interiorly of the air ducts, and connections for the ends of said straightaway portions exteriorly of the channel members.

2. In a vehicle construction, a composite floor including a sub-floor and a main floor assembly, said main floor assembly comprising a plurality of generally U-shaped inverted channel members each having a surface panel and spaced depending side flanges, said channel members being arranged in contiguity with adjacent side flanges abutting each other and supported on the sub-floor, thus providing in combination with the latter a series of parallel air ducts beneath the respective surface panels, the surface panel of each channel member being formed with a depending longitudinally extending coextensive trough portion having open ends and also opening upwardly and the bottom of which projects into the air duct, tubing adapted to contain a heating fluid, said tubing having straightaway portions disposed within and substantially filling said trough portions, and portions extending beyond the ends of the channel members for connecting the ends of said straightaway portions exteriorly of the ends of the channel members, and a removable cover plate closing the upper side of each trough member, said surface panels and cover plates presenting a continuous upper floor surface.

3. In a vehicle construction, the combination set forth in claim 2 characterized in that said tubing is continuous and is comprised of relatively thin, deformable sheet metal and each of said cover plates is formed with an expansive tubing-engaging underneath surface designed to engage and compress the tubing within the trough portion of the channel member with which the cover plate is 6 associated to force the metal of the tubing into intimate heat-transfer contact with said trough portion.

4. In a vehicle construction, in combination, a composite floor and hollow side walls partially defining therebetween a passenger enclosure, said floor including a subfloor and a main floor assembly, said main floor assembly comprising a plurality of generally U-shaped inverted channel members each having a surface panel and spaced depending side flanges, said channel members extending transversely of the vehicle and being arranged in contiguity with adjacent side flanges abutting each other and supported on the sub-floor, thus providing in combination with the sub-floor a series of parallel air ducts beneath the respective surface panels, said air ducts communicating at opposite ends with the interior of said hollow side walls, the surface panel of each channel memher being formed with a longitudinally extending coeX-- tensive trough portion presenting a convex inner face within the air duct of the member, a continuous tubing having straightaway portions disposed within and substantially filling said trough portions and having reverse bends connecting the adjacent ends of said straightaway portions exteriorly of the ends of the channel members, a removable cover plate closing the upper side of each trough member, said surface panels and cover plates presenting a continuous upper floor surface, grilles establishing communication between the interior of said side walls and the passenger compartment, a header common to all of said air ducts for supplying air under pressure to the latter, means for circulating a heating fluid through said continuous tubing, and means for supplying air under pressure to said header.

5. In a vehicle construction, the combination set forth in claim 4 characterized in that said header comprises an elongated tubular structure embedded within the subfloor and opening upwardly into each air duct.

6. In a vehicle construction, the combination set forth in claim 5 characterized in that the header opens into each air duct centrally of the latter so that air delivered to the duct may divide and flow outwardly in opposite directions toward the side walls.

7. In a vehicle construction, the combination set forth in claim 4 characterized in that the trough portions of each channel member is centrally spaced between the channel side flanges and wherein the header comprises an elongated tubular structure embedded within the subfloor and opening upwardly into each air duct centrally thereof and immediately below the trough portion thereof whereby air delivered to the ducts may divide and flow in opposite directions longitudinally of the ducts toward the vehicle side walls.

8. In a vehicle construction, in combination, a composite floor and hollow side walls partially defining therebetween a passenger enclosure, said floor including a subfloor in the form of a block of heat insulating material and a main floor assembly disposed above the sub-floor, said main floor assembly comprising a plurality of generally U-shaped inverted channel members each having a surface panel and depending side flanges, the lower ends of the side flanges resting upon said sub-floor, said channel members being arranged in contiguity and extending transversely of the vehicle thus providing in combination with the sub-floor a series of adjacent transverse air ducts beneath the respective surface panels, said ducts communicating with the interior of the side walls at opposite sides of the vehicle, a continuous tubing having straightaway portions disposed below the level of said surface panels and extending centrally and longitudinally of the respective channel members, said tubing having reverse bends connecting the adjacent ends or said straightaway portions beyond the ends of the channel members, grilles establishing communication between the interior of said side walls and the passenger compartment, a header embedded in the upper face of said block of heat insulating material and communicating upwardly with each of said air ducts, means for circulating a heating fluid through said tubing, and means for supplying air under pressure to said header.

9. In a vehicle construction, a hollow floor and hollow side walls in communication with said hollow floor, said floor and walls defining therebetween a passenger compartment, said floor presenting an upper plane floor surface interrupted at spaced regions by the provision therein of a series of parallel transversely extending troughs presenting convex heat radiating surfaces interiorly of the hollow floor, a continuous tubing bent in serpentine fashion to provide parallel straightaway portions connected by reverse bends at the ends thereof positioned on said floor surface with the straightaway-portions thereof substantially filling said troughs, means covering the upper sides of said troughs to conceal the tubing therein and present a smooth unbroken floor tread surface, means for circulating a heating media through said tubing, and means for supplying air under pressure to the interior of said hollow floor, there being openings in said hollow side walls establishing communication between the interior of the walls and the passenger compartment.

10. In a vehicle construction, a composite floor including a sub-floor and a main floor assembly, said main fioor assembly comprising a plurality of generally U- shaped inverted channel members each having a surface panel and spaced depending side flanges, said channel members being arranged in contiguity with adjacent side flanges having abutting interlocking engagement with each other and supported on the sub-floor, thus providing in combination with the latter a series of parallel air ducts beneath the respective surface panels, the surface panel of each channel member being formed with a depend ing longitudinally extending co-extensive trough portion having open ends and also opening upwardly and the bottom of which projects into the air duct, tubing adapted to contain a heating fluid, said tubing having straightaway portions disposed within and substantially filling said trough portion, and portions extending beyond the ends of the channel members for connecting the ends of said straightaway portions exteriorly of the ends of the channel members, and a removable cover plate closing the upper side of each trough member.

11. In a vehicle construction, the combination set forth in claim 10 characterized in that one longitudinal edge of said cover plate has an interlocking engagement with said channel member, and means are provided along the other longitudinal edge of the cover plate for releasablv securing it to said channel member.

References Cited in the file of this patent UNITED STATES TATENTS 1,681,582 Fjelstad Aug. 21, 1928 1,995,481 Myers Mar. 26, 1935 2,191,526 Flogans Feb. 27, 1940 2,265,536 McFarlane -2 Dec. 9, 1941