US2263998A - Heating apparatus - Google Patents

Description

Nov. 25, 1941. J. DE N. MCCOLLUM 2,263,998

HEATING APPARATUS Filed Aug. 11, 1939 3 Sheets-Sheet 2 4 H. J. DE N. MCCOLLUM Nov. 25, 1941.

HEATING APPARATUS Filed Aug. 11, 1939 3 Sheets-Shet 1 Nov. 25, 1941. J DE MCCOLLUM 2,263,998

HEATING APPARATUS Filed'Aug. 11, 1959 3 Sheets-Sheet 5 Patented Nov 25, 1941 2,263,998 HEATING AFPARATUS Henry J. De N. McCollum, Evanston, 111.

Application August 11, 1939, Serial No. 289,575

3 Claims.

My invention relates generally to heating apparatus, and more particularly to improvements in gaseous or vaporized liquid fuel burners combined with heat exchange means.

It is an object of my invention to provide an improved unit type heater using a gaseous vaporizable liquid as a source of fuel, in which combustion takes place in a rotating unit which at the same time serves as a heat exchange device.

A further object is to provide an improved burner for'gaseous and liquid fuels.

A further object is to provide an improved heat exchange apparatus of eflicient construction.

Other objects will appear from the following description, reference being had to the accompanying drawings, in which:

Figure 1 is a front elevation of the apparatus, portions thereof being broken away to show concealed parts in section;

Figure 2 is. an enlarged vertical sectional view taken on the line 22 of Figure 1;

Figure 3 is a vertical sectional View taken on the line 33 of Figure 2;

Figure 4 is a fragmentary horizontal sectional view taken on the line 4-4 of Figure 1;

Figure 5 is a fragmentary sectional view taken on the line 5-5 of Figure 2, but shown to a slightly reduced scale;

Figure 6 is a fragmentary sectional view taken on the line 6-8 of Figure'l, showing a means for supporting the unit;

Figure 7 is a wiring diagram showing an electric circuit which may be used in conjunction with the unit.

Various types of unit heaters employing gaseous or a vaporized liquid fuel have been proposed and used in the past, but for the most part such heaters have been of relatively large size com-- pared to the amount of heat produced. This was due mainly to the fact that in most instances. the natural convection was relied upon to convey heat from the apparatus, or in such instances where fans were utilized to promote the circulation of air past or through the unit, a rather bulky radiator was necessarily employed in order to transfer the heat from the gases of combustion to the air circulated through the unit.

In the present invention, the heat which is generated by the combustion of fuel is transmitted directly to the blades of the fan used to circulate the air through the unit by making the fan blades hollow and causing the gases of combustion to flow through the hollow blades. high speed of the fan blades relative to the air, the rate of heat transfer from the gases of com- By virtue of the bustion to the air is very rapid and eflicient. Furthermore, the gases of combustion flowing radially outwardly through the fan blades are centrifugally accelerated, and thus cause a partial vacuum at the point at which the fuel and air are supplied, thereby promoting the rapid circulation of the gases of combustion through the unit, and

consequently increasing the amount of heat which may be delivered by a unit of a given size.

Referring to Fig. 1, the heating unit comprising a casing Ill which is channel shaped in cross section (as best shown in Fig. 2) and which is of increasing depth in the clockwise direction (Fig. 1) so as to provide a channel l2 of gradually increasing cross sectional area, the channel terminating in a tangential outlet projection M which may be formed integrally with the casing Ill. The casing 10 may be supported in any suitable manner, depending upon the particular use to which the unit may be put, and is illustrated as being clamped topipes IB- and 18, the latter being clamped in split blocks 20 (Fig. 6) which are secured in the split ends of tubular standards 22 by means of cap screws 24. The pipes l6 and I8 are illustrated as being secured to the housing It] by brackets 26 which are provided with set screws 28,

so that the angle of the plane of the housing I!) with respect to the standards 22 may be adjusted at will.

As best shown in Figs. 1,- 3 and 4, the pipe I6 is connected to a source of-gaseous fuel by a hose 30, and is provided with a nozzle 32 which is held in position at the inner end of the pipe l6 by an adjustable set screw 34 which is clamped in position by a lock nut 36. The inner endof the set screw 34 projects into the passageway through the nozzle 32 and by suitable adjustment may be made to restrict this passageway and thereby control the rate of flow of gaseous fuel through the nozzle.

A mixing chamber 38 of generally cylindrical conformation is formed in a casting 40 which is 1 supported by the pipes 46 and I8, the ends of these pipes being suitably located in sockets formed in the casting 40 by set screws 42. It will be noted that the pipe I8 projects into a closed end socket, whereas thepipe I6 is held in a cylindrical bore which communicates with the mixing chamber 38. The forward end of the mixing chamber is provided with a plurality of openings 44 which register wholly or to an adjustable ex-' tent with corresponding openings 46 formed in a disc 48 which is rotatable upon a central stud 50 threaded in the front wall of the casting 40.

The amount of atmospheric air admitted through the openings 44 and 46 may thus be adjusted by rotating the disc 48 on the stud 58, causing the openings 44 and 48 to register to the desired extent. A disc 52 is secured to the inner end of the stud 58 and is of slightly greater diameter than a hollow cylindrical boss 54 formed integrally with the casting 48. The width ofthe space between the disc 52 and the end of the boss 54 may be adjusted by rotation of the stud 58, and may be locked in adjusted position by means of a nut 55.

Within the casting 48, beneath the mixing chamber 38, is a bore 56 (Fig. 2) in which an igniter shell 58 of generally tubular shape is secured. This casing forms a support for a coil of high resistance wire 58, the inner end of which is welded to the igniter shell 58, and the other end of which is welded to a terminal stud 62 which is insulated from the shell by suitable insulating washers and an insulating sleeve, which is held in place by a nut 64, and to which awire terminal lug 68 is clamped by means of a nut 88. The

. inner surface of the shell 58 is preferably finished .plate 12, the plate being supported, by a plurality of arms 14 which are welded, respectively, to the plate 12 and to an annular ring 16 which is secured to the channel shaped housing ID, A hollow hub 18 is secured to a flanged bushing 88 which in turn is non-rotatably secured to the rotating shaft 82 of the motor 18 by a set screw The hub 18 has a plurality of hollow fan blades 86 projecting radially therefrom, the blades fitting into suitably shaped .openings formed in the cylindrical flange of the hub I8 and being brazed or welded thereto. The outer into suitable apertures formed in a channel shaped felly 88, being brazed or welded thereto. The felly 88 fits closely within the channel shaped housing l8, the clearance between the sides of the felly 88 and the side walls of the channel housing l8 being made as small as is compatible with the free rotation of the felly 88 within the housing l8.

Similarly, the clearance between the forward edge portion of the flange 19 of the hub 18, and the casting 48 is made as small as possible without destroying the free running fit between these parts.

The outlet l4 of the housing I 8 has a pipe or other suitable conduit 98 connected thereto, this conduit leading to a flue which, due to natural convection, will draw theproducts of combustion from the outlet l4, or the conduit may be provided with a suction blower in order tocreate a partial vacuum at the outlet l4.

As illustrated diagrammatically in Fig. 7, the supply of energizing current to the apparatus is controlled by a two pole switch 92 connected to a suitable source of current. Closure of the element I82 will flex so as to break the circuit to the igniter 68. If desired, the operation of the switch 92 may be controlled by a room thermostat so that the heater is rendered operative whenever the temperature of the room drops below a predetermined value.

To cause the heater to commence operation, it is necessary merely to close the switch 92 either manually or by means of a thermostat control relay, whereupon the motor 18 will commence operating and the valve 96 opened to permit the flow of a supply of gaseous fuel to the mixing chamber 38.

The coil of the igniter 68 may be made of relatively fine wire so as to heat up rapidly. As a result the igniter will'be at ignition temperatureshortly after the flow of gas to the mixing chamber 38' commences. The gas flowing into the combustion chamber will, of course, be mixed with air flowing through the openings 44, 48 formed at the front of the combustion chamber so as to form a combustible mixture which may readily be ignited by-the igniter.

A- partial vacuum will' be formed due to the rotation of the hollow fan blade assembly which will act as a centrifugal blower to draw the products of combustion from the hub 18 and eject the gases of combustion into the space between the felly 88 and the channel shaped housing l8, whereu'pon'these gases will flow outwardly through the outlet l4 and conduit 98 either to a flue oi suflicient height to cause the necessary ends of the hollow or tubular blades 86 are fitted switch 92 completes a circuit to the electric motor draft, or through a suction blower.

As the heated gases flow radially outwardly through the hollow blades 86, the latter will of course be heated to a high temperature, and since the fan blade assembly is rotated at high speed, the rate of heat conduction from the outer surfaces of the fan blades will be very rapid, and the heat transfer correspondingly eflicient.

The rate of production of heat may, of course, be readily controlled by adjustment of the screw 34 to limit the size of the opening through which the gas is supplied to the mixing chamber 38, and the amount of air supplied may, of course, be controlled by adjustment of the position of the disc 44. Likewise, the annular opening between the plate 52 and the flange 54 may be adjusted in size by turning the stud 58 to a position which results. in combustion at the desired rate.

The adjustments are preferably made in a manner such that substantially complete combustion will take place within the hollow hub 18 which forms the combustion chamber. Since the combustion chamber is at sub-atmospheric pressure, and since the space between the casing l8 and felly 88 is likewise under sub-atmospheric pressure,- there is no danger of the'escape of the gaseous products of combustion into the room in which the heater is located, and there will, of course, be some infiltration of atmospheric air to the system through these apertures.

The infiltration of air into the combustion chamber within the hub 18 through the annular space between the flange l9 and the casting 48 may be advantageously used to assure complete combustion within the combustion chamber and be considered as part of the air supply for the proper combustion of the fuel. Infiltration of air between the felly 88 and the channel shaped housing l8 does not have any material effect except as it may add to the volume of gas which is to be. conveyed through the condult 90 and to be handled by the blower or stack. The unit may be made very small relative to Q its heat production capacity, due to the very made without departing from the underlying principle thereof. I therefore desire, by the following claims, to include within the scope of my invention all such varied and modified forms of my invention whereby substantially the results of my invention may be obtained by substantially the same or similar means.

I claim:

1. In a rotating heat radiator comprising a motor-driven fan having a combustion chamber in the hub thereof into which a combustible mixture is drawn by the suction created by rotation of said fan, the combination comprising a fuel and air mixing chamber projecting into said com-. bustion chamber, a fuel inlet for said mixing chamber, air inlets for said .mixing chamber, means for adjusting the fuel and air intake to said mixing chamber and the flow of combustible mixture to said combustion chamber operable independently of each other, said means including an axially extending stud in said mixing chamber having an apertured plate threaded on its outer end and a disc secured on its inner end, said apertured plate being rotatable on said stud to vary the registration between the apertures therein and said air inlets for regulating the flow of air to said mixing chamber, andsaid stud being rotatable independently of rotation of said apertured plate to vary the opening between the disc secured thereon and the outlet of said mixing chamber, thereby regulating the flow of combustible mixture to said combustion chamber.

2. In a rotating heat radiator comprising a motor driven fan having a combustion chamber in the hub thereof, and a support for said heater, the combination comprising a fuel and air mixing chamber carried on said support and communieating with said combustion chamber, an adjustable fuel inlet for said mixing chamber, inlets in said mixing chamber for the admission of air thereto, a longitudinally extending stud in said mixing chamber, an apertured plate threaded on the outer end of said stud, said plate being adjustable on said stud to Vary the registration of the apertures therein and said air inlets for regulating the flow of air to said mixing chamber, a plate positioned over the outlet of said mixing chamber and secured to the inner end of said stud, said stud being rotatable independently of rotation of said apertured plate to vary the opening between the plate secured thereon and the outlet of said mixing chamber, thereby regulating the flow of combustible mixture to said combustion chamber when the fan is rotating.

3. In a rotating heat radiator comprising a motor driven fan having a combustion chamber in the hub thereof with an open front end and a tubular support for said heater, the combination comprising means secured on said support for closing the open end of said combustion chamber, said means including an igniter and a fuel and air mixing chamber projecting into said combustion chamber, said mixing chamber having an apertured front end for admitting air to said mixing chamber and an open back end, a fuel inlet for said mixing chamber formed by said tubular support, means for adjusting the fuel admitted to said mixing chamber, an axially extending stud threaded in the front end of said mixing chamber, an apertured plate rotatably mounted on the outer end of stud, said plate being adjustable to vary the registration of the apertures therein and the apertures in the front of said mixing chamber for regulating the flow of air to said mixing; chamber, a plate positioned over the inner en of said mixing chamber and secured to the inner end of said stud, said stud chamber resulting from rotation of said fan and means for locking said plates in adjusted position.

HENRY J. DE N. MCCOLLUM.

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