US2545561A - Heating element for convection heaters - Google Patents

Description

March 20, 1951 B. sPlETH HEATING ELEMENT FOR coNvEcTIoN HEATERS 2 Sheets-Sheet l Filed Sept. 26, 1947 March 20, l95l B. sPlETH HEATENG ELEMENT1 FOR coNvEcTIoN' HEATERS 2 Sheets-Sheet 2 Filed Sept. 26, 1947 ifa UNHED STATES FFICE reni* HEATING ELEMENT 'FOR CONVECTION HEATERS Benjamin Spieth,

Racine, Wis.,

assignor to Medine Manufacturing Company, Racine, Wis., a corporation ofWisconsin Application September 26, 1947, Serial No. 776,363

6 Claims.

This invention relates to heating elements for convection heaters where economy in the cost of manufacture and a minimum number of kfabricated parts are of importance.

Due to the nature of the present heating element it is usually constructed of light gage and relatively expensive materials such as copper and brass, therefore, in order to provide strength and sufficient rigidity to resist external piping strains it is necessary to build as rigid a construction as possible, and though allowing for internal eX- panses at the same time maintaining production economies.

To this end I have devised a form of construction of the fins, the side plates and supporting means for the heating element for performing several functionsn and obtaining novel results.

One of the objects of this invention is to pro- Vide a fin-side plate combination which provides means whereby the side plates may be firmly attached to the ns.

Another object is to provide side plates which are also utilized as extended heating surfaces.

Another object is to solder or braze each and every fin to the side plates, whereby to prevent relative movement between the fins and the side plates due to expansion and contraction which movement otherwise results in scraping noises.

Another object is to provide side plates of light gage material provided with offset reenforcements, thus forming a relatively rigid piece.

Another object is to provide side plates that give stiffness to the fin-tube portion and prevent the light gage tubes from sagging. f

Another object is to provide side plates attached directly to the end supports, thus allowing the fin-tube portion to oat.

Another object is to provide a guard around the iin-tube assembly.

Another object is to provide iins with short flanges on their ends which are bonded to the side plates, thus providing a mechanically strong joint between the ns and the side plates.

Another object is to provide side plates bonded to the fins thereby gaining a greater area of secondary surfacesin contact with the air.

Another object is to provide supporting members at the ends of the structure which connect the side plates and at least one of said supporting members serving to give mechanical support to its associated header when the pipe is being screwed into the header.

Other objects and advantages will appear in the course of this specification and with all of said objects and advantages in View this inven- 2 tion consists in the several novel features hereinafter fully set forth and more definitely pointed out in the appended claims.

The invention is clearly illustrated in the drawings accompanying this speciiication in which:

Fig. 1 is a plan partly broken away and partly broken out of a heating element for convection heaters embodying a simple form of the present invention;

Fig. 2 is a view partly in side elevation and partly in central vertical longitudinal section of the parts seen in Fig. 1, the line of section being indicated at 2 2 in Fig. 1;

Fig. 3 is a vertical cross section taken along the line 3-3 of Fig. 2 and showing-the parts upon an enlarged scale;

Fig. 4 is an end elevation of the device looking in the direction of the arrow l in Fig. 1 and showing the device upon an enlarged scale; v

Fig. 5 is a detail horizontal fragmental section taken on the line 5 5 of Fig. 3; and

Fig. 6 is a perspective view of one of the supporting members of the device.

Referring to said drawings, which are merely illustrative of one embodiment of the invention,

the reference characters 8, 8 designate the two sidev members of the heating element here shown in the form of elongated plates, to which are secured as by soldering or brazing a multiplicity of heat radiating fins 9, the ends of each fin are formed with flanges I0 which are soldered or brazed to the side plates, and the latter are formed with outwardly offset reenforcing portions I I between the parts of the side plates to which the flanges Iil are soldered or brazed. The upper and lower edges of the side plates are formed with U-bends IIa to 'give added rigidity to the side plates. Slight spaces I2 are left between the ends of the fins and the offset reenforcing portions I of the side plates. The iins are formed of very light gage metal and may be formed with stiffening beads 9a. The side plates may be formed 0f slightly heavier gage metal than the fins and by reason of the offset portions in the side plates they are made Very stiff and rigid. Soldered or brazed to the end portions of the side plates 8 are supporting members I3 which are formed with horizontal plate members I4 which have upwardly offset end portions I5 that Yterminate in downwardly extending wing inembers I6 Vwhich engage the side plates and are soldered or brazed thereto. The horizontal plate members It are formed at their outer ends with downturned ribs or flanges I'I which may engage with suitable supports or brackets (not shown) fastened to the walls of the cabinet in which the convection heater is installed.

Extending through holes in the iins are uid conveying tubes I S, i 9 which extend between and connect a supply header 2G to a return header 2 i. Both of the headers 20, 2i are non-circular in cross section, being here shown as' oi octagonal form and the header 2i may extend through an octagonal hole 22 formed in the horizontal part lil of the supporting member I3.

Secured in openings in the inlet hea-der and extending in opposite directions therefrom are two sub-headers 23 which may be of cartridge form and the tubes I9 at one end thereof openV to the interiors of the sub-headers 23 and are soldered or brazed thereto. The corresponding end of the tube I8 enters the supply header Ztl through an opening in its side wall. The other end of the tube it enters the return header 2| through an opening in one of its side walls and the corresponding ends of the tubes i9 are bent to form elbows 2d, the ends of which enter the return header 2i through openingsl in its side walls and are solderedor bonded tosaid header. The lower end of the upp'ly header is intennally threaded for the reception of a supply pipe 25 as is cleariy seen in Fig. 2 and both ends of the return header 2l may be internally threaded' to receive a return pipe 2S and a screw plug 21"'.

All of the parts of the heating element,

least at their contacting portions, are provided with a soldering or brazing material andV the assembled heating element is placed in a suitable oven and heated to the fusing point of the solder or brazing material, which when set rigidly connect all of the contacting points' andv provide a rigid, sturdy and substantial heating element which can be economically fabricated.

Having thus described my invention, it is ob'- vious that various immaterial modincatio'ns may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combina-- tion oi parts herein shown and described or uses mentioned.

What I claim asnew and desire to secure by Letters Patent is:

l. In a heating element for convection heaters, a pair of side plates each having outwardly offset longitudinally extending reenforcing portionsdns extending between said side plates and being formed with flanges bonded to the side plates, iiuid conducting tubes extending through holes in said ns, a supply header connected to the tubes at one end thereof and! a return header connected to the tubes at the other endv thereof, and supporting members at the'V ends of the side plates each having a horizontal plate member, at least one formed with an opening' corresponding to the cross section of the associated header and formed at its outer edge with a downturned retaining flange, said horizontal plate member terminating at its ends in two vertical downward'- ly projecting wing members bonded to the side 'i plates.

2. In a heating element ior convection heaters, a pair of side plates each having outwardly offset longitudinally extending reenforcing portions, fins extending between the side plates and being formed with short flanges bonded' to the' side plates, uid conducting tubes extending through holes in said ns, a supply header connected to the tubes at one end thereof and a return header connected to the tubes at the other end thereof,

and supporting members at the ends of the side plates each having a horizontal plate member,

lli)

at least one formed with an opening corresponding to the cross section of the associated header and formed at its outer edge with a downturned retaining ange, said horizontal plate member having upwardly offset end portions terminating at their ends invertical downwardly projecting wing members bonded to the side plates.

3. In a heating element for convection heaters, a pair of side plates each having outwardly offset longitudinally extending reenforcing portions, ns extending between the side plates and being formed with. short danges bonded to the side plates, intermediate said oiset portions, fluid conducting tubes extending through holes in said iins, asupply header connected to the tubes at one end thereof and a return header connected to the tubes at the other end thereof, and supporting members at the ends of the side plates each having a horizontal plate meinberhaving upwardly oiset end portions terminating at their ends in vertical downwardly projecting wing members bonded to the side plates.

4'. In a heat exchange structure, the combination of a iiuid conducting tube, means associ-- ated with the respective ends of said tube for operatively connecting the latter to: a fluid line, a plurality of nn elements, each having` an open-- ing therein through which said tube extends, each. iin element having aY series of. spaced, verticallyv and horizontally aligned ila'nges'alongl a pairv of oppositely disposed edges, with the flanges adja-A cent corresponding edges of the respective-iin elementslying in a common plane'extending parallelto a common planel containing theranges along the other corresponding edges of the fin elements, and a pair of side'plates, each positioned adjacent respective flanged edges of the fin elements, said plates each being provided with outwardly offset, longitudinally extending portions', each.; of said portions being positioned between a pair of adjacent flanges of each iin element, said iiangesV being bonded to the respective portions ofy the plates intermediate said outwardly oiset porf tions, t-he latter providing channels in which are positioned portions of the respective nn.- elements extending outwardly beyond the planes of saidflanges.

5. In a heat exchange structure, the combination of a fluid conducting tube, means associated wit-h the respective ends of said tube for operatively connecting the latter to a fluid line, a plurality of fin elements, each having an opening therein through which said tube extends, each iin element having a seriesl of spaced, vertically and horizontally aligned flanges along apair of oppositely disposed edges, with the iange's adjacent corresponding edges of the respective iin' elements lying in a common plane extending parallel to a common plane containing the anges along the other correspondingy edges of thev fin elements, a pair of' side plates, each positionedV adjacent respective flanged edgesk of then elements, said plates each being provided with outwardly oifset, longitudinally extending portions, each of said portions being positioned between a pair of adjacent flanges of each iin element, said iianges being bonded to the respective portions of the plates intermediate said outwardly offset portions, the latter providing channels in' which are positioned portions of the respective iin elements extending outwardly beyond the' planes of said flanges, and a supporting member adjacent each pair of correspondingV ends of said plates,

said supporting members each having a pair of spaced iianges extending therefrom in spaced, parallel relation secured to the respective plates.

6. In a heat exchange structure, the combination of a uid conduit tube, a plurality of n elements, each having an opening therein through which said tube extends, each iin element having a plurality of spaced, vertically and horizontally aligned flanges along a pair of oppositely disposed edges, with the flanges adjacent correspondingedges of the respective iin elements lying in a common plane extending parallel to a common plane containing the flanges along the other corresponding edges of the fin elements, and a pair of side members each positioned adjacent respectively anged edges of the n elements, the inner faces oi.' said members having recesses therein, said recesses being positioned between adjacent iianges of each fin element. said iianges being bonded to the respecf 6 tive portions of the members adjacent said recesses, the latter providing spaces in which are positioned portions of the respective fin elements which may extend outwardly beyond the planes of said flanges.

BENJAMIN SPIETH.

REFERENCES CITED The following references are of record in the -iile of this patent:

UNITED STATES PATENTS

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