US2289287A - Heating system - Google Patents

Description

July 7, 1.942. w. w. HALLINAN 2,289,287

HEATING SYSTEM Filed Oct. 16, 1939 2 Sheets-Sheet 1 j@ Z5 i Il f 2f@ @9&4 M, @5

July 7, 1942.

Filed Oct. 16, 1939 vy. w. HALLINAN HEATFIAANG SYSTEM 2 Sheets-Sheet 2 Patented `Fuly 7, 1942 UNHTED STATES i3 OFFICE 4 Claims.

The present invention relates to heating sys-- tems, and is particularly concerned with heating systems of the type having a hot air furnace and an air blower for moving the air from the furnace to the rooms to be heated.

The present invention is related in subjectmatter to my prior application, Serial No. 196,003. filed March 15, 1938, for Variable speed pulleys, Patent No. 2,210,976, issued August 13, 1940.

Cir

Another object of the invention is the provision of an improved variable speed driving systemfor air circulating fans, which is efficient, economical, and capable of manufacture and installation at a reasonable cost.

Other objects and advantages of the invention will be apparent from the following description and the accompanying' drawings, in which similar characters of reference indicate similar parts The heating systems of the prior art of this l0 throughout the several views. character are subject to the disadvantage that Referring to the two sheets of drawings. they are either complicated or they are so con- Fig. 1 is a diagrammatic vertical sectional view structed that the volume of air circulated by the of a hot `air furnace embodying the present heatblower or fan must be adjusted to take care of ing system; the maximum heating load, which inevitably re- 15 Fig. 2' is a diagrammatic top plan view in parsults in a higher operating temperature for the tial section, showing a part of the lters; furnace, too great a volume of air put out by the Fig. 3 is an axial sectional view, taken on the fan when there is but a little demand for heat, plane of the line 3 3 of Fig. 1, looking in the and a blast of cold air from the furnace soon direction of the arrows, showing a spring pulley after the fan begins to operate, when the furnace 20 adapted to be used in the present invention;

is not operating at maximum heating load.

One of the objects of the invention is the provision of an improved heating system in which the fan may be operated continuously, or it may commence its operation at a relatively low temperature, and in which the speed of operation of the fan is continuously modulated from low speed at small furnace output to maximum speed at maximum furnace load.

Another object of the invention is the provision of an improved heating system of the class described, in which the operating temperature may be reduced to a lower value than the devices of the prior art, thus reducing the furnace losses at the stack and losses in the cellar, and providing a more eflicient heating system.

Another object of the invention is the provision of an improved heating system of the class described, which is adapted to operate within a smaller range of temperature variation for the purpose of maintaining a more uniform temperature in the rooms to be heated, and for the purpose of eliminating any possibility of a blast of cold air.

Another object of the invention is the provision of an improved heating system of the class dcscribed, by means of which the volume of air circulated in the system is dependent upon the temperature of the circulating air or of the air in the plenum chamber in the furnace, so that a j maximum efliciency of distribution of heat from the furnace is achieved and the circulating system is adapted at all times to circulate a volume of air which is required to carry away the heat from the furnace.

Fig. 4 is a fragmentary end elevational View of the embodiment of Fig. 3;

Fig. 5 is a fragmentary view showing the' installation of the thermally responsive bulb on the outside of a plenum chamber, but attached to the metal of the plenum chamber.

Referring to the drawings, l0 indicates in its entirety the installation which includes the furnace Il, such as a gas furnace, an oil burner, or

1",- a coal stoker type, controlled by room thermostats and auxiliary equipment so as to be turned on responsive to the heat demand in the rooms.

The furnace casing is indicated at I2, and it is' provided with the usual bonnet I3, having hot fair outlets to the rooms at I4.

v The cold air inlet to the furnace casing is at l5, the outlet of a fan cr blower l5 preferably of the centrifugal type, having a suitable centrifugal impeller shaft I7, which is provided with a V pulley I8.

The discharge pipe from the blower I6 passes through a hole in the wall of the furnace housing. The blower, of course, takes in air within the chamber where it is located, through intake apertures at the end of the shaft H. Thus the only cold air inlet to the furnace is through the blower I5, which takes its cold air in from the upper conduit 21.

The blower i6 is adapted to be driven by means of a V belt i9 of constant width, which is driven by a variable diameter pulley 2l) carried` by the shaft 2l of a substantially constant speed motor 22.

The blower I6 and motor 22 and other auxiliary equipment may be installed in a lter hous- 'support a plurality of suitable air filters 26,

through which the air passes to the inlet of the centrifugal blower I6, said blower being provided with an inlet at one or both of the ends of its housing, surrounding the shaft I1. Suitable cold air conduits 21 from the rooms are in communication with the cold air inlet 21 to the lter housing 23.

The blower motor 22 is preferably movably mounted by having its base 28 secured to a pivotally mounted base 29, which is carried by a j bracket 30, by means of a pivot shaft 3|.

A tension spring 32 has its upper end adjustably secured to a bracket 33, carried by the blower I6, and its lower end secured to a bracket 34, carried by the motor base 29. Thus spring 32 may have its tension adjusted by means of the nuts 35 on the threaded end of the spring, and the spring tends to urge the motor pivotally about the center of the shaft 3| in a counterclockwise direction so as to give the belt I9 a suitable tension.

The variable diameter pulley 20, carried by the motor shaft 2|, is illustrated in detail in Fig. 3. It preferably consists of a pair of pulley sections 36 and 31. vided with the radially extending flanges 38 and 39, which have the opposed frusto-conical surfaces 49 and 4I, forming a substantially V-shaped groove 42 for receiving the wedge-shaped leather V belt I9.

The pulley section 36 preferably has a centrally located circular bore 43 in the cylindrical hub 44, and the bore 43 is adapted to receive the motor shaft 2|, to which the section 36 is secured by a set screw 45 or a suitable key.

The end of the hub 44 may have a reduced threaded extension 46 for slidably receiving the spring seat 41 and receiving the threaded nut 48 and lock washer 49. The hub 44 is preferably provided with an outer cylindrical surface 5I), formed with a keyway 5| for receiving the key 52 of substantially rectangular cross section, which is also received in a groove 53 in the pulley section 31.

The key 52 may have a tight frictional iit in one of the grooves 5| or 53 and be readily slidable with respect to the other of said grooves. In other words, the key may be secured to the section 36 or the section 31, but section 31 is adapted to slide freely relative to the section 36.

The pulley section 31 is provided with the tubular or cylindrical extension 54, having an inner cylindrical bore 55 slidably mounted on the hub 44. The tubular extension 54 may have a cylindrical enlargement at 56, engaging the inside of a compression coil spring 51 of helical form, and the end of the coil spring may engage against the outer face 58 of the pulley section 54.

The opposite end of the coil spring engages the spring seat 41, which may consist of a cast metal member having a hub 59, an outwardly extending body flange 69, and a cylindrical retaining iiange 6 I.

The hub 59 has a bore 62 for receiving the reduced threaded portion 46 of the pulley section 36. The spring seat 41 may be mounted for sliding movement on the reduced portion 46, but is prevented from rotation by a rib or key 63, located in an axially extending slot 64. The out- The pulley sections are profic wardly extending flange 60 may be of frustoconical form, and there may be a radial flange for engaging the under side of the lock washer 49. The lock washer 49 may be provided with a plurality of radial slots 66, and the spring seat 41 with a rib 61 for engaging in any one of those slots.

It will be evident that the tension of the spring 51 may be adjusted by the position of the nut 48. The nut 48 may be locked in its adjusted position by the rib 61, and an inward pressure of the spring seat 41 against the spring 51 will remove the rib 61 from its groove G6 and permit an adjustment of the nut 48.

The operation of the spring pulley is as follows: The effective diameter of the pulley depends upon the point to which the belt I9 is drawn into the groove 42. This in turn depends upon the relative positions of the pulley sections 36 and 31, and the pulley sections 35 and 31 may take a position which depends on the action of the belt I9 and the belt tension.

When the motor 22 is pivoted toward the left in Fig. l, or counterclockwise, the belt I9 is drawn farther into the V groove 42, the spring 51 giving away and permitting the section 31 to recede from the section 36. This naturally decreases the effective diameter of the adjusted pulley 20 and changes the speed of drive of the blower because the driving pulley 20 is smaller relative to the size of the driven pulley I8.

When the motor 22 moves to the right or pivots in the clockwise direction, the center of the pulley I8 being xed, and the belt I9 being of constant length, the belt is permitted to ride out farther in the groove 42, the spring 51 forces the pulley sections 36, 31 closer together, and the effective diameter of the adjustable pulley 20 is increased. This increases the speed of rotation of the blower I6 because the size of the pulley 20 relative to that of the pulley I8 has been increased.

The position and movement of the motor 22 on its pivotal support 3| is preferably controlled by pressure responsive or thermally responsive means, such as a metal bellows 1D.

The blower I6 and motor 22 are carried by a base 1I, which may have an upwardly extending bracket 12 for ixedly supporting one end of the extensible metal bellows 16. The other, or right hand, end of the bellows has its face provided with a hub 13, connected to a connecting rod 14, which is pivotally secured by a pin or bolt 15 to a pivoted bracket 16, carried by the motor 22.

The bellows 10 comprises a pressure responsive device, but the pressure is preferably derived from a thermally expansible fluid which is contained in the bellows and which may be subjected to heat in any of a plurality of different ways. For example, the bellows 19 may have its fixed end in communication with a copper tube 11, which is also lled with thermally expansible fluid, and which is connected to an enlargement which is a copper bulb 18 located in the plenum chamber 19 of the furnace.

This bellows 18 may be subjected to tempera ture conditions within the plenum chamber 19.

Referring to Fig. 5, this is another modification in which the bulb 18 is carried by a metal block of high thermal conductivity, which itself is secured to the metal wall I2 of the furnace caslng.

In this case the bellows 10 is responsive to the thermal conditions in the plenum chamber as transmitted to the furnace casing I2.

The operation of the invention is as follows:

source of heat, such as a -'furnace having 'an oil burner, a gas burner, or a coal stoker, or the furnace may .be replaced by an ordinary -radiator forming a part of the steam or water heating system. In the latter case the present air conditioning system would be a separate unit, applied only to one or more of the radiators for the purpose of providing a continuous and modulated circulation of air in a room.

The thermostatic control for themotor 22 :may include a room thermostat for turning on the motor at a predetermined temperature, or the motor may be controlled exclusively 'by a furnace thermostat, such as that indicated at 9'0. In other cases the motor 22 may operate continuously at a low rate of speed, while the heating system is in operation, the motor circuit being closed by a plenum chamber thermostat 90 when the plenum chamber reaches "a predetermined value, and thereafter the speed of the motor is controlled by means of the thermostat 13.

When the plenum chamber 19 has its air at a moderate temperature, the thermostat 1D is contracted, and the motor 22 is pivoted over counterclockwise in Fig. l, a position to which it is urged by the spring 32.

The spring 32 is strong enough so that it is adapted to overcome the axial pressure of the spring 5l when the thermostat NJ is not working to force the motor in the opposite direction, and therefore the belt I9 is drawn deeply into the groove 42 of the pulley, and the pulley has its smallest effective diameter. tions the blower will be driven at a low speed because the driving pulley is smaller, and only a small volume of air will be driven through the furnace and out of the air registers.

As the temperature o-f the air in the plenum chamber increases, the thermostat 'l0 expands, moving the motor 22 toward the right on the pivot 3|, and the length of the belt l 9 being constant, the belt is permitted to ride outward in the groove 42, giving the pulley 20 a larger effective diameter. This increases the speed of rotation of the blower, and a larger volume of air is delivered, depending upon the temperature of the air in the plenum chamber.

The characteristics of the thermostatic control and the biasing springs may be made such that the relation between the temperature and volume of air delivered is substantially a straight line curve, and the volume of air delivered is substantially proportional to the temperature expressed in this manner.

When the furnace is very hot, a larger volume of air passes through it, and more heat is removed from the furnace, which is in accordance with its increased rate of production of heat. Thus the air blower system, which is the means of transferring heat from the furnace to the rooms to be heated, operates more eiciently than the devices of the prior art, and delivers more heat when there is more heat to be delivered. Yet the speed of operation o-f the blower and the temperature at which the motor is started need not be set so high as in the devices of the prior art where a blower usually is set at maximum speed in order to take care of the full load of the furnace.

The present device not only takes care of full load of heat delivered from the furnace, but also delivers a moderate amount of heat when the furnace is producing a moderate amount of heat,

Under these condiand the amount of Vheat delivered by the blower to 4the rooms in the 'form of hot air is continuously and uniformly graduated from a small amount to maximum delivery.

v Referring to Fig. 5, the operation of this modication is the same, except that the thermal bulb '18, which is filled with expansible fluid, and connected to the bellows '10, is attached by a block 8i) of high thermal conductivity to the metal I2 of the furnace bonnet.

It might be said, strictly speaking, that the thermostat is then responsive to the bonnet temperature, but the bonnet temperature follows quite closely that of the air in the plenum chamber and may differ only by a few degrees less than that of the plenum chamber. Therefore, in this embodiment the blower motor may be controlled by the temperature of the furnace bonnet.

It will thus be observed that I have invented an improved heating system which may be em- `bodied in all types of furnaces or utilized with .hot water or steam radiators for single units used in rooms.

Myv heating system provides a continuous and modulated change of delivery of heated air by means of a blower, the volume of which changes continuously and uniformly with changes in temperature of the furnace or the air to be delivered. Stratification is eliminated, and such a blower may be operated continuously without causing a cold blast of air at any time because when the air is cooler, the speed of rotation of the fan is lower, and a smaller volume of air, which is not so hot, may be delivered without causing the sensation of a cold blast.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A heat control system for air circulating blowers for hot air furnaces comprising an air blower having a shaft provided with a driven V-pulley, said blower being xedly mounted on a support to deliver air to a furnace, an electric drive motor for driving said blower, said drive motor being pivotally mounted upon said support and having a driving V-pulley, thermostatic means having one end fixedly secured to said support and the other end connected to said motor at a point spaced from its pivotal support for varying the position of said motor in relation to its spacing from said blower, whereby the spacing of said V-pulleys is varied, a V-belt engaging said V-pulley, one of said V-pulleys being provided with a pair of belt engaging members slidably mounted with respect to each other and engaged by spring means urging said members together and urging said belt into a position of engagement with part of said pulley at a greater diameter, whereby said thermostatic means varies the position of said motor and varies the position of said pulley and varies the position of said belt in one of said pulleys to change the speed of drive of said blower responsive to temperature at said thermostatic means.

2. A blower controlling system for hot air furnaces, comprising a blower provided with a driven pulley of the V-type, a support carrying said blower, a constant speed driving motor movably mounted on said support, and having a V-pulley for driving the blower, a V-belt embracing said pulleys, one of said pulleys comprising a pair of relatively movable sections spring pressed together to provide a groove of varying width and varying effective diameter, and means for controlling the speed of drive of said blower, comprising means for acting on said motor and moving it relative to said support to cause a variation in the eiective size of said variable diameter pulley by variation of the distance between the pulley centers, said latter controlling means comprising aY pressure responsive bellows having one end xedly secured to said support, and the other secured to said motor, said pressure responsive bellows being filled with a thermally expansible fluid adapted to be subjected to heat generated by a furnace, the air of which is circulated by said blower.

3. A variable drive for -air circulation of hot air furnaces comprising a support, a driven member comprising a blower, and a driving member comprising a constant speed motor, V-pulleys on each of said members,' and a V-belt embracing said pulleys, one of said pulleys having -a pair of spreadable sections engaging said V-belt, resilient means for urging said sections together, and relatively weaker resilient means for urging said members apart to maintain the belt at predetermined tension.

4. A variable drive for air circulation of hot air furnaces comprising a support, a driven member comprising a blower, and a driving member comprising a constant speed motor, V-pulleys on each of said members, and a V-belt embracing said pulleys, one of said pulleys having a pair of spreadable sections engaging said V- belt, resilient means for urging said sections together, and thermostatic means for moving one of said members relative to the other to change the distance between the centers of the driving and driven members, and to cause the V-belt to vary its eiective diameter in said two-section pulley, whereby the driven member is driven at a variable speed depending on the temperature of the thermostatic means.

WILLIAM W. HALLINAN`

Images