US1675605A - Heat-controlling apparatus - Google Patents

Description

July 3, 1928. 1,675,605

F. E. HARRIS HEAT CONTROLLING APPARATUS Filed Oct. 1925 2 Sheets-Sheet l 12 2%Wfl elk-County July 3, 1928. 1,675,605

F. E. HARRIS HEAT CONTROLLING APPARATUS Filed 0a. 1925 2 Sheets-Sheet 2 I MM IIIIIIIIII/I/IIII III 0 flow E/iamm Patented July 3, 1928.

TUNITEDVSTA'TES i FLOYD E. HARRIS, OF FLINT, MICHIGAN.

PATENT HEAT-COKTROLLING APPARATUS.

Application filed October 7, 1925, Serial No. 61,085.

This is an improvement on the device shown in myprior apphcation Serial No.

601,426, filed Nov. 16, 1922, and is also a for operating a valve in which with the aid of two motor devices three positions of the valve may be obtained, one ofthese being a position to which the valve is biased by suitable means such. as a spring. The motor devices which I have preferred to use are electromagnets, which, if desired, may

be automatically controlled as by a heat controlled device such as a pyrometer, thermostat, or the like. I have also preferably so constructed my assembly that, when desired, the tension of the biasing spring may be relieved. i. V

In the actual apparatus I have provided a plurality of valves operated simultaneously by the motor devices for the control of air and fuel. I have also formed my valves of special design so that when supplied with air and fuel from sources such as hereinafter described the proportions ofthe latter will be constant throughout the rangeof movement of the valves.

Other objects and advantagesof the invention are set out in the following specification.

In the drawings: v

Figure 1 is an end elevation of the control devices;

the control, parts being shown in section;

Figure 3 is a section on line 3-3 of F igure 2; i Figure 4.- is a section on line 4.4 of Figure 2; and a I Figure 5 is a developed View of theair valve. i p a i The reference character 2 indicates a panel upon which my control devices are mounted.

A casting 4 is secured to the panel by means of bolts 6 and is formed to provide a chamber withinwhich is rotatably mounted valve 8 in the form'of a hollow cylinder having 7 portion to the amount of rotation of the slots 10 and 12 therein. The slot 10 is of peculiar design and is adapted to register wvith port 14 formed in the upper part of the member 4 and supplied with air at con.

stant pressure by pipe 16 which leads from a suitable fan or other source ofair pressure. passes through port 14:, slots 10 and 12, and is conducted to the burner, not shown, by a conduit 18. The slot 10 is preferably of such design that thevolume of air passing therethrough varies directly as the degree of rotation of the valve throughout its range of movement. f Two factors must be considered 1 1n the design of this opening; first, the back pressure and, second, the fact that the opening 14 is of less angular extent than the opening 10. to the first, the back pressure increases as the valve is opened and consequently the size of the valve opening must increase at a greater rate than the rate of turning of the valve in order to overcome the effect of the back pressure in resisting flow of air. As a consequence, the valve opening must have diverging sides as full open position is approached, as shown in Figure 5; This divergence must also be increased in order to allow for the second. factor in design, thatis, the fact that the slot 14 is arbitrarily so chosen for convenience as to be of less angular extent than the opening 10. With this construction the OFFICE.

The air entering through pipe 16.

volume of air passing through the valve increases at a fixed rate and in direct prop valve. As the flow of fuel through the needle valve varies in the same ratio, the proportions of fuel and air remain constant throughout the range of the mechanism.

The slot 10 also preferably subtendsa p v greater angle than that through which the Figure 2 is a. vertical sectionalview of fitting 20- recessed to provide a chamber 22 for a needle valve 24 on shaft 26. The, needle valve cooperates with a seat provided in a cap 28 having threaded engagement with the fitting 20. A conduit 30 supplies fuel, such as oil or gas, to the needle valve and a conduit 32 conducts fuel therefrom to the burner. A pressure regulator ma if desired, be provided along the conduit so that the oil in the conduit is subjected to constant pressure and this pressure is such that it is at all times somuch greater than the back pressurebuilt up on the discharge side of the valve that the flow through the needle valve will vary substantially directly with the area of the valve opening througliout the entire range of adjustment and, consequently, directly with the degree of rotation of the valve. Any suitable packing means 34 may be used to prevent the leakage of oil along the shaft 26 into the air valve compartment.

The cylindrical valve 8 is provided at one end with a sleeve portion 36 in which the shaft 26 is journalled. A yoke 38 is adjustably secured to the sleeve 36 by suitable means such as a set screw 40. The yoke 38 carries a pin 42 straddled by a fork member 44 adjustably' secured to the shaft 26. By this means the air valve and the fuel valve may be simultaneously adjusted. Projecting upwardly from the yoke 38 is an arm or stud 46 preferably having threaded engagement with the yoke, and to the upper end of which is secured a spring 48 fastened at its other end to a link 50 connected to an operating handle 52. In the position shown in Figure 1 the arrangement of centers of the- parts 50 and 52 is such that the spring is held in tensioned posit-ion. By moving the lever 52 to the left the tension of the spring may be relieved. This is desirable toper'mit hand control under certain conditions such as when the furnace is being freshly fired. It also permits the apparatus to be used as a two sition control when desired. By means 0 this spring the yoke 38 and consequently the air and fuel valves are normally held in a mid or half open position; To'one end of the yoke 38 is secured a link 54' pivoted to an armature 56 of an electromagnet 58, the other end of the yoke being similarly connected by a link 60 to armature 62 of electromagnet 64. The electromagnets are, for convenience, designed for operation by an alternating current but ifdesired direct current may be used for their energization. It is now apparent that byactuating the electromagnets 58 or 64 the yoke 38' may be tilted in one direction or the other effecting either an opening or closing of the fuel and air valves. \Vhile any suitable "means, manual or otherwise, may be used for controlling the electromagnets I have preferred that they be automatically controlled in accordance with the temperature at the burner as in my prior application. I have indicated diagrammatically at 66 a contact drum which may be operated by any suitablethermally controlled means such as a pyrometer, thermostat, or the like, not shown. This drum preferably carries c n tacts 68 and 69, the former in electrical connection with electromagnet 58, and the latter in electrical connection with electromagnet 64. A spring contact member or brush T0 bearing on the drum supplies current to either of the electromagnets in accordance with the position of the drum. When the brush bears against the part 72 of the drum the circuit is broken and neither ma net energized. I have also preferably provided in mywiring connections a switch 7.4 of any lVhen the furnace is started up the drum 66 I in such'position that contact 68 engages brush 70, thus supplying current to electromagnet 58, pulling down armature 56 and tilting yoke 38 against the resistance of spring 48 thus swingin the air valveto the full open position and through the connection 42-44 swinging the fuel valve-to a corresponding position. The purpose of the connection 4244 is to allow for possible inaccuracies inalinement of the two valves. Vhen the temperature ofthe furnace rises the drum rotates to. the point where the brush 7 Oengages theportion 72 of the drum cutting off the current whereupontlie'spring 48 restores the valves to normal or mid position. furnaceis constantly fluctuating when it approaches the temperature at which it is desired that it be maintained so that the valves are at this time moving back and forth between full open and mid position with considerable frequency. 'As the tem perature of the furnace rises the drum 66 is rotated till contact 69 engages brush 70 energizingeleetromagnet 64 pulling down armature 62 and thus's'winging the yoke 38 and consequently the valves to closed position. In practice it is sometimes desirable that the a never be completely closed but remain s ightly open even in the so-called closed position to permit the passage of sufficient combustibles to maintain combustion at the burner. Here again in actual practice the valves are 'in-a more or less constant state of oscillation this time between midposition and off position. When the materials have been treated and the furnace stands idle the valves will periodically shift In practice the temperature of the from mid position to off position maintaining the temperature of the furnace at the maximum for which thecontrol is set.

With the valve openings designed as set forth the proportions of fuel and air remain constant throughout the range of adjustment. The purpose of the pressure regulator on the fuel line is to permit the use of a needle valve of simple design having a larger seat and also to obviatethe necessity of adjustn'ient of the fuel valve with respect to the needlevalve owing to fluctuations in for biasing said valvesto one position and thermally controlled means for simultaneously moving said valves to another position, said last named means comprising an electromagnet.

2. In a regulator for a burner of the type to which fuel and air are supplied by separate conduits provided with valves, means for biasing said valves to one position and thermally controlled means for moving saidv valves to a plurality of other positions.

3. The combination as set forth in claim 2, said first named position being a median position.

4. In combination, a burner, a conduit for conducting an element of combustion to said burner,-a valve in said conduit, a rock shaft for operating said valves, means for biasing said rock shaft to one position, thermally controlled means forrocking said shaft to other positions.

5. The combination as set forth in claim l, a conduit for conducting. another element of combustion to the burner, a valve in said conduit, one of said valves being mounted on said rock shaft, the other valve having a loose connection therewith.

6. The combination as set forth in claim 4, said last named means comprisingelectromagnets adapted to rock said shaft.

7. In combination, a burner, a conduit leading an element of combustion to said burner, a valve in said conduits, a rock shaft for operating said valve, a spring secured. to said rock shaft and adapted to hold it in one position, electromagnets, said magnets being operatively connected to the opposite arms of the rock shaft, and means for energizing either of said magnets.

8. The combination as set forth in claim 7, said last named means being thermally controlled.

9. The combination as set forth in claim 7, a conduit for conducting another element of combustion to the burner, a valve in said conduit, one of said valves being directly operated by said rock shaft and the other having a loose connection therewith.

10. The combination as set forth in claim 7, means for releasing the tension of said saring.

11. The combination of a conduit, a valve in the conduit resilient means biasing the valve to one position, and automatically controlled means for moving said, valve to other positions.

19. The combination of a burner, a conduit supplying fuel to the burner, a valve in said conduit, resilient means for biasing the valve to one position, and thermallycontrolled means for moving said valve to other positions.

13. In a fuel burner, the combination of a plurality of coaxially arranged valves, and an operating device for said. valves, said operating device having a loose connection with one of said valves to facilitate assembly.

14. The combination of a burner, a conduit for supplying fuel to the burner, a valve in said conduit, a conduit for supplying air to said burner, a valve in said conduit, means for yieldingly holding said valves in one position, an electromagnet for moving said valves to another position, and thermally controlled means for controlling the operation of said magnet.

In testimony whereof I affix my signature.

FLOYD E. HARRIS.

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