US1701012A - Electric hot-air furnace - Google Patents

Description

Feb. 5, 1929. 1.701,012

G. J. ROHN ET AL ELEc'rRIc HOT yAIR FURNAGE Filed Sept. 24, 1923 5 Sheets-Sheet l ATTORNEY Feb. 5', 1929. Y 1,701,012

G. J. RoHN ET A1.

ELECTRIC HOT AIR FURNAGE Filed sept.24. 192s s sheets-sheet 2 AgoRNEY 4' Feb. 5, 1929. 1,701,012

G. J. ROHN ET AL ELECTRIC HOT AIR FURNAGE Filed sept. 24. 1923 s sheets-sheet 5 ATTORNEY U BY wd @emmen Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE.

GILBERT J'. ROHN AND ARNOLD PFAU, JR., OF MILWAUKEE, WISCONSIN, ASSIGNORS, BY MESNE ASSIGNMENTS, T GLOBAR CORPORATION, OF NIAGARA FALLS, NEW

YORK, A CORPORATION OF NEW YORK.

ELECTRIC HOT-AIR FURNACE.

Application led September 24, 1923.

Our invention relates to a hot-air furnace, and is particularly designed for utilizing electricity as the source of energy for supplying heat.

li The objects of the invention are to provide a. hot-air furnace which is simple, economical and practical, and which utilizes to the maximum advantage all, or substantially all, of the heat units generated.

Generically, this invention comprises a draft cylinder' in which a heating unit is enclosed. The heat is producedby a resistance element which is relatively small with respect to the cylinder, and to compensate for the proportional difference, radiator plates are employed to eiiicaciously distribute the heat.

To the accomplishment of the recited objects and others subordinate thereto, the preferred embodiment of our invention resides in the the construction and arrangement of parts hereinafter described, illustrated in the accompanying drawings, and embraced within the scope of the appended claims. p

In said drawings Figure 1 is a vertical elevation, partly in section, of the furnace embodying our invention.

Figure 2 is a transverse section taken along lines 2-2 of Figure 1, and

Figures 3 and l are detail side elevations of one of the radiator plates., and the water manifold, respectively.

Figure 5 is a top plan view of Figure 4.

Figure 6 is an enlarged fragmentary elevation of one of the radiator plates, illustrating the manner of mounting the resistance element.

Figure is a sectional view taken on line 7 7 of Figure 6.

Figure 8 is an enlarged fragmentary elevation, partly in section, of the uppermost supporting connection of the radiator plates.

Figure 9 is a sectional view talren on line 9-9 of Figure 8, and

Figure 10 is a transverse sectional view taken on line 10-10 of Figure 8.

Referring to the drawings, and at first 50 more particularly to Figure 1, (5) represents a cylindrical casing constructed, preferably, of galvanized sheet iron, and suitably connected sind reenforced adjacent the top,

Serial No. 664,464.

at the bottom, and an intermediate point, by iron rings The upper extremity of the casing is merged into a truncated crown (7) having a substantially concave top (8) and suitable hot air outlets (9) leading to registers (not shown). At the bottom, the casing is equipped with a cold air inlet (10) and a door (11) for convenience in filling the water pan (12).

One or more radiators, preferably in the form of substantially rectangular shaped plates (13), together with a similarly shaped water manifold (14), provided with an inlet (15) and an outlet (16), are combined with suitable electric resistance bars (17) to produce the desired heat for the furnace. If certain contingencies require that all of the radiators, including the manifold, should be equipped with electric resistance bars, this could be done with facility. However, actual experiments which we have conducted show conclusively that for ordinary requirements, it is necessary to provide only the alternate plates and the manifold with the resistance bars, and this is the manner in which the disclosure is made in Figures 1 and 2 of the accompanying drawings.

As illustrated, the plates have lugs (18) at their inner opposite corners which are secured at the top to the bars of the heat deflector, or inverted dome, (19) by bolts (20), and at the bottom to the flange (21) of the upright (22), transverse slots (22 a) being formed at the base of the lugs for receiving nuts (22 b) A separate upright (23) is employed to sustain the manifold (1li). 'When in place, as exhibited in Figures 1 and 2, the plates (13) and manifold (14) are disposed .in the upper portion of the casing, and radiate from their' inner adjacent edges outwardly to a point near the inner wall of the casing, suflicient space being allowed between the outer edges of the plates and the wall of the casing to accommodate a. cylinder (24) of asbestos-lined tin, or similar heat insulator, as well as to provide for a dead air space (25). The concave top (8) of the crown of the easing is also preferably filled with a heat insulator, as quartz sand (26).

In accordance with the present showing (see Figures 6 to 8 inclusive), each alternate plate (13) and the manifold (14) arecast with a diagonal slot (27) medially v'vitbin'v mes of which are mounted the resistance bars (l'f- Specifically, opposite ends of the bar are gripped by a clamp (f2.8) which are in turn suspended by coil springs to allow for expansion and contraction. Screws (30) serve to fasten the springs (29) to a bridge (8l) of fireproof insulation, as tti-:insite asbestos, secured transversely of the terminals of the slot by bolts The screws (30) also serve a connection for ti electric wires (38) and (3f-l) which are insulated by an asbestos cover and led through conduit to a mutual outlet box (36). lnterconnections (87) between the electric resistance bars (i7) as required by delta connection, are led through the plain. radiator plates and are supported on them by porcelain bushings (38).

rllhe maximum heat pressure will obviously be exerted at the top of the radiator plates, and it therefore becomes necessary to provide a construction which will protect the crown (7) against heat radiation. We accomplish this by means of the hereinbefore mentioned heat detlector (19), which not only functions to connect the upper' ends of the radiator plates, but, combined with the concavity (8) of the top of the crown, leads the hot air into the outlet pipes (9) and reverses the direction of ascending heat towards the path of incoming air and the radiators.

An electric switch (not shown) can be placed exteriorly of the furnace, or the circuit may be connected with suitable switch mechanism which in turn is controlled by a thermostat (not shown). f

Manifestly, a draft is produced more readly by suction than by pressure, and it is for this reason that the radiators are located the upper part of the casing. Cold air entering through the inlet 10), contacts with the radiators which are heated by the resistance bars. It will be understood in this connection that the plates carrying the resistance bars are heated first, and that the heat thus generated is radiated to the imperforate plates. As the heat rises it strikes the deflector which absorbs and radiates it in vertical and transverse planes and outwardly throughthe outlets (9) to registers (not shown) in various rooms of the house.

le have shown siX radiator units, inclusive of the water manifold, but it is obvious that this arrangement can be varied at will. The precise contour of the heat deflector, and other structural features, may also be altered without departing from the spirit and principle of our invention.

What we claim, is

l. A hot air furnace comprising a casing provided with an inlet and an outlet, plurality of spaced plates supported within said casing and extending longitudinally in the general direction of and exposed to the flow of air through said casing, certain of said plates each having a longitudinal slot extending through the plate, .an electrical resistance element mounted within each slot, and electrical connections for said elements.

2. A hot air furnace comprising a casing provided with an inlet and an outlet, a plurality of plates radially supported within said casing, the alternate plates having slots, an electrical resistance element mounted within each slot, and electrical connections for said elements.

3. A hot air furnace comprising a casing provided with an inlet and an outlet, a water manifold supported within said casing and also provided with a water inlet and a water outlet, said manifold having its side wall provided with a slot therein terminating short of the ends of the manifold, an electrical resistance element mounted within and substantially free of the walls of said slot, and electrical connections for said element.

4. An electrically heated appliance comprising a casing, a metal radiator plate having an velongated slot therein and mounted within said casing, an electrical resistance elemernJ of bar-shape havingr a smaller diameter than the width of said slot and being mounted in said slot with! the body portion of said resistance element free of the walls of said slot, and electrical connections for said resistance element. i

5. An electrically heated appliance comprising a casing, a single-piece water manifold mounted within said casing and having a water inlet and a water outlet, said manifold being provided with a lengthened slot in the form of an aperture extending wholly through the material of opposed walls of said manifold, the ends of said slot being defined by hollow water-containing portions of said manifold, a longitudinally extend ing resistance element mounted in and spaced from the walls of said slot, and electrical connections for said element.

6. An electrically heated air-heating furnace comprising a casing, a radiator plate arranged upright within said casing and having attachment lugs at opposite corners, and provided with a diagonal slot, an electrical resistance element mounted within said slot, and electrical connections for said element.

7. A hot air furnace comprising a casing provided with an inlet and an outlet, an upright support, a heat deflector, a plurality of radiator plates lsecured vertically to and between said upright support and said de- Hector, electrical resistance elements carried by certain of said plates, and electrical connections for said elements.

8. An electrically heated appliance comprising a casing, a radiator plate disposed Within said casing and having a yslot therein, an electric resistance element arranged niedially of said slot, a clamp for opposite ends of said element, a bridge disposed transversely of said slot, and a yieldable member between the clamp and the bridge.

9. A hot air furnace provided With an inlet and an outlet, a plurality of radiator plates arranged vertically adjacent the upper portion of said casing, a support for the base of said plates, an inverted dome secured ad- `jacent the top edges of said plates, and a concave top for the casing, said dome and said concave top serving conjunctively as a heat deflector.

l0. A hot air furnace comprising a oasing provided with an inlet and an outlet, a plurality of radiator' plates mounted in said casing, electrical resistance elements carried by certa-in of said plates, a heat de* tlector, simulating in contour an inverted truncated cone, secured to the upper edges of said elements below the top ot said casing.

l1. A hot air furnace comprising a casing provided with an inlet and outlets, and a concave top between the outlets, a plurality of radiator plates mounted in said casing, electrical resistance elements carried by certain of said plates, a heat defiector, simulating in contour an inverted truncated cone, secured to the upper edges oi'f said elements below the top of said casing, the said cou-- cave top and said deflector being spaced apart and occupying a relatively nested relationship.

12. A hot air iurnace comprisingr a easing provided with an inlet and outlets, and a concave top between the outlets, a plurality of plates radiating` from the center of the casing, electrical resistance elements carried by certain oi" said plates, a heat deiector, simulating in contour an inverted truncated cone secured to the upper edges of said elements below the top of said casing, the said concave top and said deector being spaced apart and occupying a relatively nested re* lationship.

13. A hot air furnace comprising a casing provided with an inlet and an outlet, a plurality of radiator plates arranged perpendicularly and extending substantially onehalf of the height of the casing, and means for electrically heating said plates.

Signed at Milwaukee, in the county of GILBERT J. RoHN. ARNOLD PFAU, JR.

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