US2362940A

US2362940A - Control for fuel economizers

Info

Publication number: US2362940A
Application number: US438148A
Authority: US
Inventors: Roy P Skerritt
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-04-08
Filing date: 1942-04-08
Publication date: 1944-11-14
Anticipated expiration: 1961-11-14

Description

1944- R. P. SKERRITT CONTROL FOR FUEL ECONOMIZERS 2 Shets-Sheet 1 Filed April 8, 1942' Gttomegs Nov. 14, 1944. R. P. SKERRITT CONTROL FOR FUEL ECONOMIZERS 2 Sheets-Sheet 2 Filed April 8 1942 fa zs/zeri'i? @aw 6 7 Gttomegs Patented Nov. 14, .1944

. 2,352,940 con'raon FOR rusnnconomznas Roy r. Skerrltt, Detroit, Mich.

Application April 8, 1942, Serial No. 438,148

4 Claims.

The present invention relates to heat economizers, and more particularly to a control therefor.

- The primary object of the invention is to provide a device for utilizing the heat carried oil in gaseous form from a furnace vor heater by passing said gases of combustion through a heat exchanger having means for conveying heated air to desired locations in a house or building.

Another object of the invention, is to provide a device as set forth in the preceding object which is particularly applicable to furnace structures which have been converted from a coal fired boiler to a gas or oil type burner so that the heat from the gaseous products of combustion passing through the furnace will be utilized instead of being conducted to the atmosphere through the flue and stack.

Another object of the invention is to provide a heat exchanger of unique construction having a passageway communicable with the furnace flue and passages extending transversely thereof for conducting air through said exchanger so that the air exhausting therefrom may be used for heating rooms in addition to the conventiona1 house heating system.

Another object of the invention, is to provide a heat exchanger of the above mentioned type having a force feed fan which is adapted to be controlled by a thermostat in the flue pipe on 80 the outlet side of the heat exchanger so that in the absence of heat in said flue, the operation of the fan or other air force feed means will be discontinued to prevent the feeding of cold air to the room or rooms coupled to the heat exchanger.

Another object of the invention, is to provide a heat economizer which is adapted to be employed for supplying heated air to a room of a building in which the furnace control thermostat is placed so that said room will receive additional heat and the furnace control thermostat will govern the furnace heater in accordance with said heat, whereupon an ideal heating condition will exist inwhich one of the rooms will be maintained at a higher temperature, such as the living room so that the bedrooms of the building will not be overheated and will be properly conditioned for healthful sleeping.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawingswherein: I

Figure 1 is a side elevation of the device embodying the invention illustrating the same coupled with a conventional hot water heating system and showing diagrammatically the manner of supplying additional heat to one of the rooms in a building;

Figure 2 is a vertical cross sectional view taken on line 2-2 of Figure 1 looking in the direction ofthe arrows illustrating the transverse air passage through the heat exchanger and the manner of creating a forced draft therethrough;

Figure 3 is a top plan view of the heat exchanger partly broken away and greatly enlarged to further illustrate details thereof.

Figure 4 is a vertical cross sectional view taken on line 4-4 of Figure 3 looking in the direction of the arrows showing the structure of the heat exchanger per se;

Figure 5 is a longitudinal cross sectional view taken on line 5-5 of Figure 3 looking in the direction of the arrows illustrating the forced draft means and showing a humidifier on the outlet side of the heat exchanger, and;

Figure 6 is a perspective view of the heat exchanger illustrating portions of the casing broken away to clearly show the construction thereof.

Figure 7 is a side elevation of the air supply valve.

General arrangement -'I'he invention comprises a rectangular casing adapted to'be interposed in the flue pipe of a furnace, which furnace has been converted to a gas or oil type heater so that the furnace gases will travel through said rectangular casing and cause heat to be transferred .by induction to transversely extending passageways through which air is conducted by means of a blower or other force feed means. The heated air from the rectangular casing is then conducted to one of the rooms of a building for supplying additional heat thereto, which additional heat will raise the temperature of the room and allow the burner control or thermostat therein to be more easily-satisfied, thus resulting in a further saving of fuel and the prevention of house overheating. Further, the invention consists bf providing thermostatic means in the'f'urnace flue on the outlet side of the heat exchanger for con trolling the force draft means so that said forced draft means will cease operation inthe absence of heat in the flue pipe below a predetermined degree. It is contemplated that the thermostat operate to cut off the force feed means when the temperature in the flue drops to a predetermined degree dependent upon the operation of the furnace heater so that cold air will be prevented from being forced through the exchanger and into the room, and the gases will be prevented from being condensed which condensation it allowed would result in deleterious eifects and damage to the casing structure through corrosion.

Detailed descriptionv In the drawings, wherein for the purpose of illustrating the invention and wherein like reference characters will be employed to designate like parts throughout the same, the reference character it will generally be employed to designate a conventional furnace having a boiler structure coupled to a radiator il in a room l2 by means of a pipe IS. The room l2 may constitute a living room of a building above the cellar foundation H in which\ the furnace II) is usually placed.

The invention is adapted to be applied to heating systems in which the furnace in has been converted to a gas or oil fired type and for the purpose of illustration, an oil burner type heater i5'is shown in Figure 1 having a blower l5 supported by a suitable pedestal II. The blower it of the oil burner is controlled by means of a switch mechanism i8 mounted thereon in the form of a relay so that closing of said switch will establish electrical contact with the supply lines 19. A thermostat is located in the room l2 adjacent the radiator II and is coupled to the relay switch l8 by line wires 2| so that said thermostat may operate the relay l8 and thereby control the motor blower i6.

In converted furnaces of the above type, the outlet for the burned gases is placed adjacent the top of the furnace and as indicated in Figure 1, includes a. flue pipe opening 22 for receiving a flue pipe adapted to be coupled to the stack extending through the foundation wall l4.

The invention includes a heat exchanger generally designated by the reference character 24 and said heat exchanger is shown indetail in Figures 2 to 6 inclusive. The heat exchanger comprises a casing having a bottom wall 25 and a top wall 26 connected by end walls 21 and 28. The end wall 21 is provided with converging portions connecting a circular flue pipe section 29 which is adapted to be inserted in the flue pipe opening 22 0f the furnace III. A damper 30 is interposed in the flue pipe section 29 and is provided with an operating handle 3| so that the damper may be swung on its pivot to control the flow of hot gases to the casing 24. The opposite wall 28 is provided with a tubular section 32 centrally mounted thereon which has its end as at 33 extending into the chimney or smokestack of the building, having communication therewith through the foundation wall I4.

Convergent side walls 35 connect the end walls 21 and 28 as well as the bottom and

top walls

25 and 26, and said convergent walls terminate in acircular flange portion 36, further tapered at 35a, closed by a perforated end wall 36a, providing an opening in the casing for the passage of air currents therethrough. A disk valve 35b is rotatably secured to the perforate end wall 38a so that the perforation in said walls may be brought into registry to control the volume of air through the air passageway and thereby prevent the flue gases from being cooled to such an extent as to cause damage to the casing structure from the condensation of said flue gases. Monuted on the circular flange 35 is a motor supporting bracket 31 secured in place by means of bolts or the like as at 38 and the upper end of the bracket 31 as at 21 is adapted to support a motor 40 having an armature shaft 4i provided with a fan 42 the hub of which as at 42 is rigidly secured to the armature shaft to rotate therewith. The opposite side wall of the casing as at 44 is provided with a centrally disposed tubular section 45 for connection with a vertical air pipe 45 having an elbow 41 for connection with a hot air register 45 by means of an L-shaped connector 45, the foot portion of which as at extends through the floor l2 of the room so that hot air may be conducted to said room under forced draft from the fan 42.

Mounted within the heat exchanger casing 24 is a pair of oppositely disposed header plates 50 and 52 which are identical in structure and are provided with openings 53 for receiving the ends of flat heat exchanger tubes 54. The tubes 54 are formed from thin sheet metal and provide transverse passageways 55 for conducting air currents through the casing in the direction of the arrows indicated in Figures 5 and 6. The openings 53 provide relatively long spaced header strips 58 for connecting the ends of adjacent tubes to provide hot gas passageways 51 arranged alternately on opposite sides of the passageways 55 and relatively flat plate-like tubes 54. This structure provides for the allowance of heat induction between the passageways 51 and the passageways 55 extending at right angles thereto so that heat exchange will occur and the air forced through the passageways 55 will reach a relatively high temperature upon the outlet side 45. Since the heat conduction surfaces are equal, the air on the exhaust side 45 of the casing will reach a temperature equal to half the temperature of the hot gases combined with the temperature of the air on the inlet side 36 of the casing.

The outlet side 45 of the casing is formed with a humidifier chamber 50 by spacing the header plate 52 from the side wall 54 a sufficient distance as is shown clearly in Figure 3. An opening 6! is formed to one side of the end wall 28 and said opening is preferably formed rectangular in shape for receiving a humidifier trough 52 extending the full width of the humidifier chamber 50. The trough 52 is provided with a marginal upstanding side wall 63 and connecting the upstanding ide wall 63 is a ledge portion 54 to which is hinged a cover 55 as at 55. The trough 82 may be inserted in the rectangular opening 5| so that the ledge 64 projects therein to prevent the escape of hot air from finding its way through the trough and to the atmosphere. The humidifier trough may be filled with water by raising the cover 55 and filling the trough to the desired level.

Mounted in the tubular flue section 32 is a thermostatic control member 61 which projects into the casing into the path of the hot gases passing therethrough as indicated in Figure l. A bushing 58 is formed on the thermostatic member 51 and is provided with a casing 59 in which is located a switch element having contacts Iii which are in series with a source of current supplied through a lead line H and connecting the motor 40 by a lead line'12. A lead line 13 is connected to the motor 40 to the opposite side of the power source to complete the circuit.

Mode of operation For consideration of the operation of the invention, it will be first assumed that the furnace l0 and the burner I6 are inoperative by reason of the heat in the room 12 satisfying the thermostat 20. Under these conditions, the thermostat 61 will be in a position to maintain the normally open switch 69 in its open position wherein the motor will be at rest as will also be the fan 42.

so that heat conducted thereto from the flue gases traversing the passageways 51 will cause said air to be heated and conducted to the humidifier chamber 60 where it is passed over the humidifier tray 62 and thence to the register 48 in the room II.

In this manner, additional heat is supplied to the room I! whereby the temperature therein will be raised by the heat from the radiator II and also by the heat entering the room through the register 48. Obviously, the room temperature will reach the desired degree more quickly so that the thermostat will be satisfied and cause the relay l8 to cut the burner blower l6 out of the supply line If! and thereby stop the operation of the furnace and burner l5. When this condition exists, heat from the products of combustion is likewise ended and the temperature in the circular flue section 32 will start to fall so that the switch within the casing 69 will open and cut off the motor 40 and the forced draft operation of the fan 42. The cycle of operation above described will continue to maintain the room l2 at a proper temperature with a smaller consumption of fuel in the burner l5 resulting in a considerable saving of maintenance cost.

It isto be understood that the form of the invention herewith shown and described is taken as a preferred embodiment of the same and that various changes in the shape, size and arrange- I ment of parts may be resorted to without departing from the spirit of the invention or the scope of the subioinedclaims.

What I claim is:

1. A. heat exchanger comprising a rectangular casing, a plurality of relatively flat air tubes extending transversely through said casing, a plurality of contiguous flue gas passageways formed at right angles to said air tubes, means withinsaid casing on the inlet side of said relatively flat air tubes for creating a forced draft of air.

therethrough and a humidifier within said casing on the outlet side of said relatively flat air tubes for humidifying the heated air passing from the heat exchanger through said contiguous flue gas passageways.

2. A heat exchanger comprising a rectangular casing having a series of spaced relatively flat passageways for flue gases, a series of relatively flat transversely extending tubes mounted in said heat exchanger forming air passageways therethrough' and betweensaid series of spaced relatively flat flue passageways, a blower on one side of the heat exchanger within the casing for creating a forced draft of air through said tubes and a humidifier on the outlet side of said transversely extending air tubes within the casing for humidifying the heated air, said humidifier being located beneath the outlets of the major portion of said air tubes in air contact relation thereto.

3. A heat exchanger comprising a cruciform casing having aligned flue passageways, a series of spaced-relatively flat transversely extending tubes mounted in said casing, header plates for the ends of said tubes, the spaces between said tubes being in communication with said flue passageways in the casing and providing flue gas conduits, a' blower supported in the casing at the air inlet side of said tubes for creating a forced draft of air through said tubes, 8. humidifler mounted within said casing at the outlet side of the transversely extending tubes and heat responsive means in the outlet side of the flue passageway responsive to temperature changes within said flu'e passageway for controlling the blower,

4. A heat exchanger comprising a cruciform casing having aligned flue inlet and outlet pipes. a series of relatively flat transversely extending tubes mounted in the casing between said flue inlet and outlet, header plates having openings for receiving said tubes, a blower within the casing and one of said header plates on the inlet 45 side of the relatively flat transversely extending tubes for creating a forced draft of air through said tubes, a humidifier located within the. casing between the other header plate and the outlet side of the relatively flat transversely extending tubes and a thermostatic switch mounted in the direct path of'gases in the outlet flue passageway responsive to temperature changes therein for controlling said blower.

nor a smarrr.