US3211079A - Vent cap for gas heating structure - Google Patents

Description

Oct. l2, i965 VENT Filed June 25, 1964 R. E. CARLSON CAP FORGAS HEATING STRUCTURE 2 Sheets-Sheet 1 Oct. l2, 1965 R. E. CARLSON VENT GAP FORGAS HEATING STRUCTURE 2 Sheets-Sheet 2 Filed June 25, 1964 United States Patent O This invention relates to gas tired heaters with sealed combustion chambers especially for house trailers, cabins, yachts, homes, cabin crusiers, sailboats and the like. This application is a continuation-in-part of my earlier application, Ser. No. 201,441, led lune 11, 1962.

With heaters of the type to which this invention is applii cable, combustion air to supply the gas burners in the sealed combustion chambers is drawn from the outside air rather than from the interiors of the spaces being heated. With such heaters it is also the practice to vent the combustion chambers laterally from the upper portions thereof out through the buildings sidewalls, and to draw the outside combustion air through a concentric air pipe surrounding the vent pipe.

Lateral venting with concentric horizontal piping has heretofore been deemed to be t-he only satisfactory construction for heaters with sealed combustion chambers, apparently because it has been thought that fresh combustion air ow to the combustion chamber could be satisfactorily accomplished only by horizontal flow at a low level from the exterior of the structure to be heated.

However, such heater constructions have various objections, including the sidewall venting, variable draft conditions, and hot vent caps at low levels outside.

It is a general object of this invention to provide a space heating and venting means which eliminate all such objections. It is a particular object of this invention to provide a space heating structure which is vented through the roof and at the same time to employ a vent cap which retains the concentric piping arrangement of sidewall venting, the outside combustion air being brought down around the Ihot vent pipe from a position above the roof, rain being effectually excluded, and mixing of incoming air wit-h exhaust gases being etfectually prevented.

Still another object of the invention is to transfer the typical vent cap to an elevated position so that such vent cap, which often becomes quite hot, is not in a position to burn persons passing the side of the building as where horizontal piping is vented.

A further object is to provide a vertical venting and piping arrangement extending through the roof wherein a vent cap structure is employed which not only diverts rain or water spray from entering the exhaust venting pipe, but also covers the cool air intake pipe to guard it against the entry of rain or spray.

Briefly outlined, the present improvement includes an upstanding two-element heating member disposed vertically in a shallow casing or housing often known as a linen The forward element of the heating member constitutes a sealed re box or combustion chamber at the lower end of which a burner is positioned and at the upper end of which there is an outlet passage to a vertical ilue or vent pipe mounted on the heating member and extending up through the buldings roof to vent the combustion gases. The other element of the heating member is a ilattened air chamber element disposed behind the lire box or combustion chamber, both elements being attached to an intervening radiation partition. This ilattened chamber element is in the form of an air supply chamber enclosed on all sides and at its top and bottom, except that its top provides an intake opening for cool air and its forward wall at the bottom provides an opening connected by an air duct to the lower portion of the 3,211,079 Patented Oct. 12, 1965 rice combustion chamber to feed such cool air to the burner to support combustion. The upper end of the air chamber is provided with an air intake duct which leads downward from an annular space within a collar upstanding from the heater member and receiving the lower end of an outer concentric air intake pipe leading down from the roof around the exhaust pipe.

Above the roof, the top of the exhaust pipe carries a vent cap under which the spent combustion gases are discharged, such cap having plate means arranged to prevent Imixing of exhaust gases with incoming air and having special means such as a vertical ring for excluding rain or spray from the exhaust pipe and also guarding the air intake pipe to exclude rain or spray therefrom. Thus, pre-warmed cool air is fed from above the roof down through the annular space between the exhaust pipe and the air intake pipe where it enters the upper end of the air chambers whence it passes to the lower end ofthe combustion chamber, the spent combustion gases then rising through the outlet from the combustion chamber into the central exhaust pipe by which they are discharged through the roof by way of the vent cap which both excludes rain and prevents mixing of the spent combustion gas with down-draft cold air moving to the combustion chamber. Convection air rises around the combustion chamber in front of the radiation partition, and also rises around the intake air chamber which is heated by radiation from the combustion chamber via the radiation partition, such heated air passing forward and outward through the upper portion of a grill or front panel into the living space of the building, radiation heat being projected directly forward from the combustion chamber through the grill into such living space.

Further objects and features of the invention will become apparent to those skilled in the artjupon reference to the following specification and the accompanying drawings wherein a presently preferred form of the invention is disclosed.

In the drawings:

FIG. l is a prespective view of the vent cap and heating structure of lthis invention disclosed as installed in a wall of a small building, portions of the wall being broken away;

FIG. 2 is a vertical section from front to back taken as indicated by theline 2 2 of FIG. 1;

FIG. 3 is a cross-sectional view through an intermediate portion ofthe heater;

FIG. 4 is a vertical section on an enlarged scale through the vent cap hereof; and

FIG. 5 is a similar view of a varied assemblage.

The present improvement is shown especially in the upper portion of FIG. 2 and in FIG. 4 which illustrates the arrangement of the Vent cap and air supply and exhaust pipes upstanding from the top of the heater.

As indicated, the entire heating structure is arranged for installation within a wall of a house trailer or the like in which it is to be used. Whereas laterally vented gas heaters must be disposed in an outer wall, the present structure, being vented through the roof with the vent cap above the roof, may be mounted in an interior wall.

With particular reference to the drawings, a Wall structure is illustrated as including a typicalrearward wall panel 10, a forward orinner wall panel 12, aroof panel 14 or other roof structure, and a pair of upstanding supporting and spacing studs 1S, all of which are carried on anappropriate lloor structure 18. l

A primary heating member or unit generally indicated at 20, which is illustrated as an upstanding gas red sheet metal structure, is supported in a rectangular housing orliner 22, also metal, from which there upstands apipe assemblage 24 having an outervent cap assembly 25 above theroof 14. The pipe assemblage includes acentral exhaust pipe 26 and an outer concentricair feed pipe 28 affording an annular cold-air conductingchannel 30. Desirably, there is also an interveningconcentric radiation pipe 32 which provides an innerannular air channel 34, whereby further to reduce the temperature of theair pipe 28. Thesepipes 26, 28, and 32 are flxedly carried by the top of theheater unit 20.

The heater unit includes two spaced upstanding connected elements. Theforward element 35 provides an enclosed combustion chamber 36 having a forward upper wall portion parallel to forward and rearward parallel walls of arearward element 38 which provides an enclosed cold-air supplying chamber 39. Both of theseelements 35 and 38 are, in general, rectangular in design similar to the rectangular construction of thehousing 22, but they are appreciably smaller in order to be mounted in spaced relation in thehousing 22 and provide adequate air circulation spaces around them. Also theelements 35 and 38 are rigidly connected. At their lower ends, this rigid connection is made through the medium of a connectingair tube 40 welded to the opposing walls of the two elements and providing a duct to feed cool air from the lower end of theair passing chamber 39 to the lower end of the combustion chamber 36 which contains at such lower end aburner 42 of any desired construction. The upper portion of the burner is disposed between two opposedbafiies 43 which control the flame. The upper ends of theelements 35 and 36 are rigidly connected by welding thereto a metal rectangular approximatelycubical box 44 whosebottom wall 45 is provided with a circular opening orport 46 around which is welded to thebottom 45 the lower end portion of theexhaust pipe 26. Rearward of the circular opening orport 46, thebottom 45 of such box is also provided with a transverse rectangular opening orport 48 which provides an air feed passage into the top of theair chamber 39 of thereaward element 38.

Therearward element 38 provides a vertical elongated rectangular passage constituting theair chamber 39 formed between aback wall 50 and afront wall 51 of theelement 38, such passage extending from theinlet port 48 down to theair discharge duct 40 which feeds fresh air to the burner. Theback wall 50 and the back wall of thebox 44 are thus in substantial vertical alignment. In this manner, a constant supply of cool air is supplied from theannular channel 30, and also from theannular channel 34 if theradiation tube 32 is used, down into the cool-air chamber 39 by way of therectangular port 48 and thence via theduct 40 to theburner 42.

The forward wall of themetal box 44 is in approximate vertical alignment with the back wall of theheater element 35. Upon the top of thebox 44 there is welded a nearly square or rectangular plate ortop wall 54 which fits under thetop 55 of thehousing 22 when the parts are in the assembled relation illustrated. Thisplate 54 has welded on the top thereof acollar 56 over which the lower end of theouter air pipe 28 fits. The greater portion of theplate 54 is provided with a rectangular opening orport 58 located within the confines of thecollar 56 and through which opening the lower portion of thevent pipe 26 extends to thebottom wall 45 of thebox 44. Also, descending fresh air enters through theopening 58 from theannular passages 30 and 34 and passes around thevent pipe 26 to therectangular port 48 in thebottom 45 of thebox 44 by which port 48 theair chamber 39 in therearward element 38 is supplied. Thus, the approximatelysquare plate 54 affords within the collar 56 a narrowforward shelf portion 54a immediately forward of thevent pipe 26 and desirably tangentially contacted thereby, and also lateral shelf portions. The inward edges of these shelf portions are welded to the top edges of the vertical walls of thebox 44.

In order to centralize the lower end of theradiation pipe 32, a set ofspring spacing clips 60 is provided, either on the inner wall of thecollar 56, or mounted on the lower end of theradiation pipe 32 as shown.

For mounting the upper end of theouter air pipe 28 in theroof 14, acollar 62 having an attachedflange 62a, as seen in FIGS. l and 4, is mounted and calked at 61 on top of theroof 14, and an upper end portion of theouter air pipe 28 extending above the roof is within the collar. Thiscollar 62 which thus also surrounds the upper ends of thevent pipe 26 and theradiation pipe 32, acts to center thepipe 28 in the corresponding roof opening 63. Thevent cap 25 is shown as including a short cylinder orring 64 which acts as a wind-guard and is carried around an upwardly tapered rain-sheddingcap 65 in suitably spaced relation byclips 66 or the like. This tapered disc orconical cap 65 acts to distribute the spent gases rising through thevent pipe 26, and also to exclude rain from thepipe 26 as well as from thepipes 28 and 32. For these purposes asleeve member 68 depends in suitable relationship below thetapered cap 65, as by depending directly from a spaced large flange orannular plate 70 connected to the under side of thetapered cap 65 byspacing clips 72 or the like. Thesleeve 68 fits over the upper end of thevent pipe 26, any appropriate spacing means, such asspring clips 73, being employed to retain concentric relationships between thesleeve 68, thepipe 26 and thepipe 32. The upper end of thecollar 62 is secured byclips 74 to theplate 70 which thus imparts concentricity of thepipes 26 and 32 with theouter pipe 28. Of these pipes, thevent pipe 26 is the longest and reaches theplate 70. Theouter pipe 28 may be the shortest and supplies cold combustion air. Thepipe 32 may be intermediate in length as shown.

By such means, spent combustion gases rising through the concentriccentral vent pipe 26 are discharged above theplate 70 and below the taperedcap 65, and cool air is received under theplate 70 and through theannular channels 30 and 34, which air descends through the openings orports 48 and 58 to feed the fresh air to thechamber 39 in therearward element 38 and supply theburner 42 by way of theduct 40 leading to the lower end of the combustion chamber 36, as previously indicated.

Such avent cap 25 as above described is shown on a much larger scale in FIG. 4 wherein thedisc cap 65 is indicated as approximating a segment of a large sphere, as is the paralleling underlyingannular plate 70. In this larger scale figure, thering 64 is seen as having downturned and upturned reinforcing upper and lowerinner flanges 64a to stiifen the structure materially. The assembly of FIG. 4 indicates the omission of the intermediate orradiation pipe 32 of FIG. 2, thus providing a single annular downdraft channel 30a. However, where desired, as when maximum heat is to be generated by an appropriate burner, theintermediate pipe 32 may be retained as indicated in FIG. 5. Thus, these parts are concentric and have a common vertical axis. In these structures it is desirable to provide means for limiting relative upward movement of theexhaust pipe 26 in thesleeve member 68, and of theouter air pipe 28 in thecollar 62. For these purposes, the top of thecollar 62 is provided with at least one overhanging tongue orfinger 67 welded to the outer wall of thecollar 62, against the under side of whichtongue 67 the top of theouter pipe 28 may engage. Similarly, at least one overhanging tongue 67a is welded at the top of thesleeve member 68 against the under side of which the top of theexhaust pipe 26 may bear. Thesetongues 67 and 67a assure against relative movement of thepipes 28 and 26 above the tops of thecollar 62 and thesleeve member 68 respectively, so as to avoid reduction of the air intake space under theplate 70 and of the exhaust discharge space under thedisc cap 65. In order to insure a similar elevational relationship when theintermediate radiation pipe 32 is used, the lower ends of the spring clips 73 may be provided with offset fingers 73a to catch under the lower edge of thesleeve member 68.

In the particular form of heater illustrated in FIG. 2, thecombustion element 35 includes a perpendicular rear wall 75 (approximately aligned with the forward wall of the box 44) andaforward wall 76 which desirably includes a downwardly and outwardly slopingportion 77 so that the lower portion of the combustion chamber 36 is somewhat enlarged. Near the upper end of the charnber 36 abafl'le 78 is disposed in transverse relationship whereby to deflect the spent combustion gases laterally around its ends (which, as seen in FIG. 3, are spaced from theside walls 79 of the element 35) and facilitate heat absorption by the walls of theheater element 35, aswell as control draft. At the middle upper portion of the back wall 75, an outlet 80 is provided above thebaffle 78. This outlet 80 communicates with a correspondly narrow partially cylindrical venting channel member 82 (FIG. 2) which is welded at its upper end around thecircular port opening 46 to thebottom wall 45 of thebox 44.

In this manner spent combusion gases pass from the chamber 36 by way of the outlet or discharge passage 80 into the venting channel member 82 and thence to thevent pipe 26.

As has previously been indicated, theforward heating element 35, which is in the nature of a combustion chamber, and therearward element 38, which is in the nature of a cool air supplier, are rigidly connected together through the weldedtubular duct 40 at their lower ends and through the sides of the overlyingrectangular box 44, and also through the medium of itsbottom wall 45, at their upper ends.

For the purpose of mounting theelements 35 and 38 in the housing orliner 22, the side walls of the latter are provided with vertical channel members 85 (FIG. 3). These channel'members providevertical channels 86 for the passage of a portion of the air to be heated and taken from the living area of the trailer or other quarters in which the structure is installed. This air enters through the bottom of a grill 90 (FIGS. l and 2) secured at the front of thehousing 22 and rises up around theheater unit 20. That air which rises through thechannels 86 serves as an insulating medium to cool the side walls of thehousing 22. Thechannel members 85, which also act as supporting members for the heater unit, carrybrackets 92. To these brackets there is secured as by means of screws 93 a transverse intermediate supporting and positioningradiation plate 94, this plate being cut away to accommodate the tubularcool air duct 40 at the bottom of the structure and to accommodate the lower end of therectangular box 44 and the spent-combustiongases discharge member 82.

For the purpose of mounting theheating unit 20, including the forwardcombustion chamber member 35 and the rearward coolair supplying member 38, upper andlower brackets 95 are welded at their opposite ends to thepositioning plate 94 and the back wall 75 of thecombustion chamber element 35. Similarly, upper andlower brackets 96 are Welded to the back of the transverse supporting wall orplate 94 and to thefront wall 51 of theair supplying element 38. When the edges of thetransverse plate 94 are secured to the4brackets 92 by thescrews 93, the entire heating unit is rigidly secured within thehousing 22, and in spaced relation to all of the walls of thehousing 22. Thus, air entering the lower portion of thehousing 22, from the living space within the trailer being heated, rises partly through thelateral air channels 86, and partly up around the forward com- Ybustion chamber element 35 both forward and rearward of the latter. Some of the air also passes in behind the supporting andradiation wall 94 and rises up around theair supplying element 38 which gathers considerable heat through the supporting andradiation wall 94. Air which is heated convectionally by thecombustion chamber element 35 passes outward through the upper portion of the combustion gases.

6grill 90. Radiation heat also passes outward through thegrill 90.

For the purpose of better controlling the discharge of the heated air from the upper portion of thehousing 22, a pair of slopingbaffles 98 and 99 are disposed above theheater unit 20. Thelower baffle 98 deflects the heated air rising aronud thecombustion chamber element 35 outward through thegrill 90. Thisbale 98 is disposed between the twochannel members 85. Theupper baflle 99, which also is disposed between the twovertical channel members 85, cooperates with theunderlying bae 98 to provide in air discharge through an upper portion of the grill for that portion of the air which rises around theair chamber member 38. Theupper baille 99 extends to the back wall of thehousing 22 and thus serves to deflect forward above it only that warmed air rising through theair channels 86 at the sides of the heating installation. Both these baffles are notched to accommodate therectangular box 44.

The construction of theburner 42 is not a part of this invention, and any eicient approved gas burner is usable. It includes acontrol knob 100 and, if desired, a pilot light and thermostat control. A swinging door or cap 102 (FIG. 3) for controlling access to a lighting hole may also be provided as indicated. l

In the operation of the present structure, when theburner 42 is in operation, spent combustion gases rise to the top of the combustion chamber 36 and around thebaffle 78, whence they pass out through the vent opening 80 and the channel member 82 and thence up through thevent pipe 26 to be discharged through thevent cap 25 above the roof. At the same time cold air enters from above the roof through the lower part of thevent cap 25 below theannular plate 70 into theouter air pipe 28 and downward by way of theannular air passages 30 and 34. Thence the cold air passes down into therectangular box 44 around the lower end of thevent pipe 26 and enters therectangular port 48 at the top of theair chamber 38, whence it travels to the bottom of such chamber and from that point through theduct 40 into the bottom of the combustion chamber 36 to supply theburner 42. By these means, only external air is used to support combustion, and air within the trailer is only recirculated over the heating elements for warming the living area of the trailer or other structure involved.

The functioning and arrangement of the parts of thevent cap 25 eliminate possible mixing of exhaust gases with the incoming cold air and are such as to exclude rain and spray. This is true because thedisc cap 65 is annularly spaced from thering 64 suiciently to accommodate all combustion gases which thus rise up along the inner wall of thering 64 and because theannular plate 70 is annularly spaced from thering 64 suliciently to insure air draft up through the annular space around theplate 70 and through theannular space 165 around the cap 65vunder draft influence of the rising hot Thus, only rising cold air can enter thespace 168 around thesleeve 68 and beneath the plate. 70. Such rise of cold air to thespace 168 may even be facilitated by the draft. For these purposes, the diameters of thecap 65 and theplate 70 are substantially equal.

At the same time, thering 64 completely encloses thecap 65 and theplate 70, its upper edge extending above thedisc cap 65 and its lower edge extending below theplate 70 and being substantially even horizontally with the upper end of the outer sleeve orcollar 62. This arrangement effectually excludes all rain or spray from thevent pipe 26 and thecollar 62. This is true even with winds.

Thus, these arrangements make it possible to place a gas heater of the indicated type in an interior wall rather than only in an outside wall. In either instance, the heater is installed betweenstuds 15 which are adequately heat-insulated by the various described rising-air passages between the walls ofthehousing 22 and theheater elements 35 and 38. In such a heater, the height of thecombustion chamber 35 and theair chamber 38, whose individual heights are about equal, is about twice their width; and the height of thebox 44 extends such overall height about 20% or 25%. For example, in a typical common size, the height of theelements 35 and 38 is about eighteen inches and their width about eight t nine inches, while thebox 44 adds approximately another four inches, Here, the thickness of eachelement 35 and 38 at their tops is about one inch, and they are spaced about two inches apart, with theradiation wall 94 disposed about equidistantly between them. This leaves adequate spacing, with a minimum of about one inch between theheater 20 as a whole and the walls of thehousing 22, which housing may have a width of about eleven or twelve inches and a depth of about six and onehalf to seven inches. Thevent pipe 26 typically is two inches in diameter, theouter air pipe 28 is four inches in diameter, and the interveningradiation pipe 32 is three inches in diameter. Thering 64 has a diameter of about eight and one-half inches and a width of about two inches, while the diameter of thedisc 65 and theplate 70 is about seven inches. Spacings between thecap 65 andplate 70 of around three-fourths to one inch, and between theplate 70 andcollar 62 of around one-half to threefourths inch, insure good draft and cold air entry. These parts extend upward from the top of the heater to a position above the roof, and commonly add another five to six feet in overall height.

It is thus seen that I have provided an improved sealedcombustion-chamber gas heater and vent cap for boats, mobile homes, larger homes, and the like, which make it possible and desirable to vent gaS-red heaters up through the roof and to locate them in interior walls as well as outer walls.

The invention claimed is:

1. In a heater vent cap to be disposed horizontally above a roof:

a rain and wind excluding ring in horizontal disposition and arranged about a vertical axis;

an upwardly tapering disc cap secured within said ring in spaced relation from said ring radially to provide a substantially annular venting space, the top of said ring lying above said disc cap;

an annular plate disposed in spaced relation below said cap to provide between the plate and cap a horizontal venting space for combustion gases leading to said annular venting space, said plate also being spaced radially from said ring to yield a substantially annular draft space therearound;

a positioning sleeve secured about a central Opening in said plate and extending downward to receive a vent pipe;

a mounting collar attached to said plate in spaced relation around said sleeve to provide a down-draft cold air passage between said sleeve and said collar; and

means mounting said plate in spaced relation above the top of said collar for admission of cold air to said passage.

2. A structure as in claim 1 including means on said collar and said sleeve to limit upward movement of pipes therein.

3. A structure as in claim 1 wherein the top of said collar is substantially horizontally even with the bottom of said ring to exclude rain.

References Cited by the Examiner UNITED STATES PATENTS 2,764,972 10/56 Ryder 126-307 2,856,837 10/58 Thulman 98-46 2,909,113 10/59 Hatcher 98-46 JAMES W. WESTHAVER, Primary Examiner.

Claims (1)

1. IN A HEATER VENT CAP TO BE DISPOSED HORIZONTALLY ABOVE A ROOF: A RAIN AND WIND EXCLUDING RING IN HORIZONTAL DISPOSITION AND ARRANGED ABOUT A VERTICAL AXIS; AN UPWARDLY TAPERING DISC CAP SECURED WITHIN SAID RING IN SPACED RELATKON FROM SAID RING RADIALLY TO PROVIDE A SUBSTANTIALLY ANNULAR VENTING SPACE, THE TOP OF SAID RING LYING ABOVE SAID DISC CAP; AN ANNULAR PLATE ABOVE IN SPACED RELATION BELOW SAID CAP TO PROVIDE BETWEEN THE PLATE AND CAP A HORIZONTAL VENTING SPACE FOR COMBUSTION GASES LEADING TO SAID ANNULAR VENTING SPACE, SAID PLATE ALSO BEING SPACED RADIALLY FROM SAID RING TO YIELD A SUBSTANTIALLY ANNULAR DRAFT SPACE THEREAROUND; A POSITIONING SLEEVE SECURED ABOUTA CENTRAL OPENING IN SAID PLATE AND EXTENIDNG DOWNWARD TO RECEIVE A VENT PIPE; A MOUNTING COLLAR ATTACHED TO AID PLATE IN SPACED RELATION AROUND SAID SLEEVE TO PROVIDE A DOWN-DRAFT COLD AIR PASSAGE BETWEEN SAID SLEEVE AND SAID COLLAR; AND MEANS MOUNTING SAID PLATE IN SPACED RELATION ABOVE THE TOP OF SAID COLLAR OF ADMISSION OF COLD AIR TO SAID PASSAGE.

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