US1533800A - Apparatus for controlling steam pressure in boilers - Google Patents

Description

April 14, 1925; 1,533,800 F. HENNEBOHLE APPARATUS FOR CONTROLLING PRESSURE IN BOILERS 2 Sheets-Sheet 1 77i @wfaik jzdefzzr I I April 14, i925.

F. H ENNEBOH LE APPARATUS FOR CONTROLLING STEAM PRESSURE IN BOILERS Filed FeB. 11, 1921 2 Sheets-Sheet 2 1 to provide Patented Apr. 14, 1925.

FRANK HENNEIBDIILE, OF CHICAGO, ILLINOIS.

APPARATUS F011 CONTROLLING STEAM PRESSURE IN BOILERS.

Application filed February 11, 1921'. Serial No. 444,253.

1' '0 all whom. it iii-(41y novice 1%..

Be it known that I, FRANK Hnnnneonnn,

a citizen of the United States, residing at Chicago, in thecounty of Cook and State of Illinois, have invented certain new and useful Improvements in Apparatus for Gontrolling Steam Pressure in Boilers, of which the following is a specification.

The invention relates to anapparatus for controlling the pressure in steam boilers, and more particularly to automatic means for varying the rate of fuel combustion in the the box of a boiler by the employment of a forced draft of varying volume to supplement the natural draft and further by providing controls for the natural draft.

In steam power plants, the boilers are usually subjected to varying demands in the consumption of steam by the power units being operated there-by.

The variable load upon a steam engine driving industrial equipment, for example, wherein the operation of the machinery involves the irregular use of power, is directly reflected in its consumption of steam. lVith a sudden increase of load, and consequent sudden increase of steam consumption, the boil 1' pressure is drawn down and the efficiency of the engine is seriously reduced at the period of greatest demand.

Gbviously, increased steam consumption requires a proportionately increased steam production in the boilers to maintain evenly a desired steampressure, a requirement to be met by increasing the amount of heat generated in the fire box.

Conversely, when the steam consumption is decreased andthe boiler pressure thereby rises above that which it is desired to main tain, it is necessary to reduce the steam production by checking combustion in the firebox.

Pressure regulated dampers heretofore have been used in the smoke flue, the damp or being operable, by increased boiler pres sure, to partially close the flue and check the draft from the fire. The damper being fully open with normal boiler pressure, such a device is oln'ioiisly not adapted to cause an increase in combustion when the boiler pressure is decreased below normal.

It is the principal object of this invention in connection with. a pressure regulated. damper operating to check the natural draft of the furnace When the same is abnormally great, positively acting automatic means controlled by the boiler pressure, for increasing or decreasing the volume of an induced draft to supplement the natural draft inthe the box, as the boiler pressure falls below. or rises above a predetermined point, thereby increasing or decreasing combustion in the fire box, and, in either case, restoring the desired boiler pressure.

boiler equipped with draft inducing means embodying my invention. Fig. 2 is a sectional view of the controlhng valve as employed in smaller un ts, and Fig. 3 is a sectional view of my valve as adapted to larger units. A

Referring to Flg. 1 which is more or less diagrammatic, the numeral 1v indicates a boiler of conventionnal type, having a smoke stack '2 and a steam dome 3 from which a Another object is to provide in connection steam line t leads to a steam engine or other translational devices (not shown). The boiler may be equipped with a. mechanical stoker having chain grates 5 and'a feed hopper 6. An ash pit running beneath the box, extends forwardly of the boiler and 1s covered by a floor plate 7. A centrifugal blow-' er 8 is adapted to force air through atube 9 opening-into the ash pit through the plate 7. The blower is actuated by a steam turbine 10 receiving itssteam supply from a pipe 11 leading from a controlling valve 12, which latter is connectedby a pipe 13 to the steam dome 3. The valve 12; isadapb ed, as hereinafter more fully described, to regulate automatically the supply of steam to the turbine 10.

The valve 12 may be adjusted to menu to operate the damper.

tain a. given steam supply to the turbine, under normal conditions of boiler pressure and steam consumption, whereby a sufficient draft is supplied to the, grates to support a balancing fuel combustion and stea1irproduction. With a lowering of pressure in the boiler and pipe 13 due to abnormal steam consumption, the, valve 12 automatically admits an increased steam supply to the turbine 10. Speedingupthe latter and the blower 8, increases the forced draft through the grates and builds up the boiler pressure with theincreased rate of fuel combustion. After normal operating conditions are restored the valve 12 operates to cut down the steam supply to the turbine, and reduce the draft tothe grates.

A partial shut-down of the power plant, reducingthe' steam consumption below normal and raising the boiler pressure, causes the controlling valve to further reduce the steam supply to the turbine and proper tionately reduce the air supply to the lire.

The controlling valve may be manually closed against automatic operation, as may be desired in case of a shut-down, or to pre vent excessive draft during the firing up of a boiler preliminary to its being put in service.

The great advantage in boiler plant operation which'I have accomplished in automatically balancing? fuel combustion and steam production with boiler pressure and steam consumption, through the variable range of. power demands, may be effected by my automatic'valve control in COJl'llJlIlZltion with other draft inducing means, than that herein illustrated, as, for example, the employment of steam jets in the tire box or stack recei 'ing their steam supply from the controlling valve.

To effect amore rapid checking of the rate of fuel combustion. when the. boiler pressure rises above that of normal operation as, for exai'nple, where the draft inducing means has been cut out of ope 'ation but becauseof an abnormal natural draft, or because of other conditions, the fuel combustion is too great, it may be desirable to supplement the operative result fromthe automatic control of the blower by employing a pressure cont-rolled damper in the smoke-flue auton'iatically operable to close the flue and check the fire until normal pressure is restored.

Any well-lnown or preferred construction of controlling device may be employed That herein illus trated and indicated generally at 14L comprises a steam connection A leading from the; steam dome 3 to a condensation chamber inthe casing B. A pipe G connects the lower end of the casing'B, with the upper endpof, the cylinder I) mounted on a fixed bracket E suitably secured to the side of the boiler. A reciproca'tory piston F operating within the cylinder carries a piston rod PIV- otally attached to one end of the lever (i having its fulcrum pivoted on a support if fixed to the bracket E. A memberl adjustably mounted on the bracket E is adapted to limit the upward n'ioven'ient of the lever G as may be desired. To the other end of the lever G is attached a cable J running through sheaves K and L to a lever M being attached to one end of that lever. The lever M is rigidly secured to a shaft \l extending through the smoke-flue 2 and having suitable hearings, in the walls of the stack. lVit-hin the flue a damper O is rig idly mounted on the shaftand is adapted in its operative movement to open or partially close the smoke flue. The opposite end of the lever M carries a suspended weight P adapted to oppose the movement of the lever by the cable and maintain the latter in taut condition.

In the operation of the auxiliary damper device, steam passing through the connection A is condensed in the chamber 15, the condensation water therefrom passing through the pipe G into the cylinder 1) into operative contact with the piston F. The weight P and the relation of the opposite ends of thelevers G and M to their respective fulcrums are so arranged that the increase of boiler pressure above a predetermined maximum pressure results in forcing downwardly the piston F thereby op erating the lever G, the cabl J and the lever M to turn the damper 0 within the due and elfect a partial closure thereof. The degree of closure of the flue effected by this n'iovement of the damper is predetermined by the position ofthe stop pin in the adjust- 'end of the lever G. o

It will be seen that in the case of excessive boiler pressure, the damper is operated to aid in checking combustion in the fire box, but that the damper is inoperable by itself to effect an increase in the draft under conditions of decreased st am pressure below that normally to be maintained with the flue open. In thelatter event, increased combustion in the fire box is effected wholly by supplementing the natural draft by means of the automatically operating draft inducing blower.

My preferred construction of the con-trot accomplished, and as illustrated in Fig. 2

its seat.

ling valve, by means of which the automatic regulation of the draft inducing blower is 7 is adapted for use with a boiler. installation of moderate size. For large batteries of boiler-s I employ the constructionillustrated in Fig. 3, which embodies a. balanced valve member and large flow capacity.

Referring to Fig. 2 the numeral indi cates a tubular valve body havingv an inlet 16 and an outlet 17, both of the latter being adapted -tor connection with steam piping. An integral web 18 effects a closure of the interior of the body and is formed with a plane portion 19 parallel to the axis of the body and having an aperture 20, the upper marginal edge of which forms a valve seat.

A laterally extending, cylindrical casing 21 is fixed in an opening in the side of the body 15, having an open, end of its interior chamber in register with the valve aperture 20. A valve member 22 carries a head 23 adapter. to efiect a closure 01 the valve aperture 2111Cl'f1O1l'1 which depend crossed wings 24-. ex tending into the casing 21. A piston 25, carried by the wings 24: is reciprocably engaged in steam-tight contact with the inner walls of the casing 21. A pair oi oppositely coiled compression springs 26 and 27 are confined between the piston and a support 28 located in the closed outer end of the casing and tend toforce the piston toward the valve body and raise the valve head from The oppositely arranged pitch of the coiled springs prevents their catching one upon the other in operation. An air vent 36 provides for the escape of air trapped by the reciprocating piston. A screw threaded spindle 29, entering through the closed end wall of the casing 21, engages the support 28 oppositely to the compression springs. A hand wheel 30 is mounted on the outer end of the spindle. A look nut 31 is provided to secure the spindle in any desired position. A cap 32 is secured in an aperture through the side of the valve body 15 positioned opposite to and concentric with the valve aperture 20. A screwthreaded stem 33 extends through the cap 32 and has a flange 34: adapted to abut the valve head to force the latter to its seat. A hand wheel 35is mounted on the outer end of the stem.

In operation the flange 3 is turned down to secure the valve head 23 in its seat until it is desired to utilize forced draft with the boiler. The flange 34: is then backed off, releasing the valve head to be raised from its seat by the springs 26 and 27. There upon live steam from the boiler connection 13 entering the inlet 16 flows in the direction indicated by the arrows through the aperture 20 and outlet 17 to the blower actuating turbine 10. The degree to which the valve head will open the valve aperture depends upon the relation between the steam pressure upon the upper or inlet side or the head 23 and the tension of the springs 26 and 27. The spring tension may be adjusted by turning the spindle 29 in or out oi the casing to move the support 28, and increase or decrease the compression of the swings. A balanced relation may be obtained by such an adjustment at any boiler pressure which it is desirable to maintain. Fluctuations from that boiler pressure operate to relieve or increase the steam pressure upon the head in variable opposition to the constant spring tension, resulting in the automatic iurther "opening or closing of the valve aperture and the increase or decrease oi steam supply to the blower actuating turbine.

Referring to the modified form oi greater capacity illustrated in Fig. 3, the controlling valve comprises a body 15" having an inlet 16 and an outlet 17. A closure 1S integral with the body is provided with a pair of concentric valve apertures 20? and20 forming valve seats. A cylindrical casing 21" extends laterally from an opening in the body in which it is secured with its axis coincident with the axis of the valve apertures.

A valve member 22 carries a head 23 adapted toseat in the valve aperture 20,'

and also a valve diaphragm 23" adapted to effect a steam tight closure of the valve aperture 2 1)". Crossed wings connect the head 2; a and the diaphragm 23", and from the latter depend supplemental wings 24? extending into the casing 21. A piston 25" isfixed on the lower ends of the Wings 24 in reciprocable steam tight engagement with the interior surface or the wall Offthfi cas ing 21*". A coiled compression spring 26 is tensioned between the piston 25 and a support 28 located in the outer closed end of the casing, and tends to force the piston inwardly and disengage the valve head and diaphra m from their seats.

'llhe construction ojl -the parts 29 to 36 corresponding parts 29 to 36 inclusive in Fig. 2, need not be further described.

In its operation the last described valve construction is similar to that first described except that the valve member 22 is balanced. in the relation of the valve head 23 and the diaphragm 28 to the stream pressure in the valve inlet. The steam pressure upon the upper face of the head 23" is counter opposed by the pressure upon the lower side of the diaphragm 23 of similar cross area. Also in the present structure the piston 25" receives the full boiler pressure from the inlet side of the valve, and is designed to operate the valve member in its automatic closure of the two valve apertures.

The counter opposed tension of the spring 26 may be adjusted to the steam pressure upon the upper face of the piston 25 to secure the same operative results, as previously described in that connection.

It will now be apparent that I have provided effective means for accomplishing the objects set forth, and have thereby accomplished substantial economies and uniform efliciency in the operation of steam plants equipped with my invention.

I claim as my invention:

1. A control system for regulating the passage of pressure fluid in proportions inverse to the supply pressure comprising, in combination, a fluid pressure source, a fluid consumer, a valve between said source and said consumer adapted to control the fluid consumed, said valve having a valve member balanced on its outlet side and controlling communication from the inlet to the outlet side of the valve, spring means tending normally to open said valve member, said spring means being most forceful in the closed position of the valve member, a piston arranged for motion by pressure thereon from the inlet side of the valve, said piston being ar- "anged to move said valve member toward closure by an increase of pressure on said piston, and said spring means being adjusted to hold said valve member in open balanced position in the normal use of the valve against the force of said pressure on said piston.

52. A control system for regulating the passage of pressure fluid in proportions inverse to the supply pressure con'iprising, in combination, a fluid pressure source, afluid consumer, a valve between said source and said consumer adapted to control the fluid consumed, said valve having a valve member balanced on its outlet side, means tending to close said valve member by increasing pressure on the inlet side of the valve, and other means tending to open the valve independently of the fluid pressure, said means being most toreetul in the closed position of the valve, and said two means being arranged to oppose each other to balance the valve member between its xtreme positions in the normal use of the valve.

8. In combination, a source of fluid pres sure, a fluid consumer and a self-contained automatic valve between said source and said consumer, said valve having a valve member therein balanced on the outlet side whether opened or closed and movable to vary the opening of the valve, said valve out of use being normally wide open, and Said valve member being movable toward closure by an increase in pressure in said source, whereby in use the valve member regulates the passage of pressure fluid thru said valve in proportions inversely related to said pressure.

4. A control system for regulating the passage of pressure fluid in proportions inverse to the supply pressure comprising, in combination, a fluid pressure source, a fluid consumer, a valve between said source and said consumer adapted to control the fluid consumed said valve having a valve member balanced on its outlet side and controlling passage of fluid therethru said valve member being arranged for motion toward closure by pressure from the inlet side of the valve, and means opposing said motion with a "force increasing toward closure ot the valve member, wherebythe valve member tends to become balanced in operation to move with variation of either force to a new balanced position.

ber, whereby the valve member tends to become balanced in operation to move with variation of either force to a new balanced position, and means to vary the force of the motion opposing means.

6. In afluid pressure supply line, a valve having a valve seat therein between the inlet and the outlet of the valve, a valve c011- stantly balanced on its outlet side and movable to close said seat by pressure of the fluid supply at the inlet, mechanical means tending to open the valve member with a force inversely proportional to the extent of opening of said valve member, whereby said valve member becomes balanced by said means acting against the fluid pressure at the valve inlet, whereby to regulate the passage of fluid thru said valve inversely as the fluid pressure varies. I

In testimony whereof, I have hereunto set my hand.

FRANK HENNEBOHLE.

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