US1496005A - Apparatus for controlling boiler water feed - Google Patents

Description

- June 3, 1924.

. H. B. LEE

APPARATUS FOR CONTROLLING BOILER WATER FEED Original Filed May 14, 1918 2 Sheets-Sheet 1 TRI UGA Pu P.-

June 3, 1924. v v H. B. LEE

APPARATUS FOR CONTROLLING BOILER WATER (FEED 2 6 g 4 m z 6 7 v k, 5:22 a A m 5 7 a w M a A w W J, M w m s m E m7 m J. w M Ma ,s K v EN 1 H z 7 4? I, u w I U 271/ A I "T H 4, 1 Q ,///r w /4 z a 2 1 4 I 0 .ln EV K fi l Patented June 3, 19 24.-

HENRY '3. LEE, or NEW LONDON, CONNECTICUT, assmNon, BY MEsNE ASSIGNMENTS,

TO THE D. E. WHITON PORATION.

MACHINE Ca,

OF NEW LONDON, coNNECTICUT, A COR,-

, APZPARATUS FOR CONTROLLING BOILER WATER FEED.'

Application filed an 14, 1918, Serial No. 234,466. Renewed November 1, 1923.

To all whom it may concern:

Be it known that I, HENRY B. LEE, a citizen of the United States, residing at New London, in the county of New London and State of Connecticut, have invented a new and useful Improvement in Apparatus for Controlling Boiler Water Feed; and I do hereby declare the following, whentaken in connection with the accompanying drawings, and the characters of refei ence marked thereon to be a full, clear, and exact description of the same, and which said drawings constitute part of this application, and represent, in 1 a Fig. 1 a view in side elevation of a boiler water-feed apparatus constructed in accordance with my invention.

Fig. 2 a broken view thereof in vertical central section through the follow-up pressure regulator, the emergency governor, and

the steam control valve.

Fig. 3 a detached view in inside elevation of-the inner end of the follow-up pressure regulator.

My invention relates to an apparatus for regulating/the water-feed of'steam boilers,

the object being to provide a simple, efficient, reliable and effective follow-up apparatus for automatically maintaining a predetermined excess of pressure in the boiler water-feed line over the pressure in the 1 steam line notwithstanding fluctuations of pressure therein due to changes in the load or fire. In other words, my improved apparatus is designed to regulate the pump speed so that the water pressure will follow the boiler pressure up and' down, always maintaining suflicient excess of water pressure and no more, to cause water to -flow to. the boiler, whereby no more water pressure is built up than is necessary for feeding the water to the boiler against the pressure thereim Boiler water-feed systems using centrifugal rather than reciprocating pumps as at present generally constructed, provide fortdriving the pump at a constant predetermined speed regardless of fluctuations of pressure in the steam line, with the result that when additional load is placed upon'the boiler, or when the fire needs coaling or burns low, and the steam pressure is thereby reduced, the water pressure remaining unchanged floods'the boiler with water and retards the production of more steam at the very time when more steam or heat is required to carry the load.

With these ends in view, my invention consists in a follow-up apparatus having certain details of construction as will be hereinafter described and pointed out in the claims. 7

In carrying out my invention as herein shown, I employ a steam turbine 2, a centrifugal water pump 3, and a flanged coupling 4, all of any approvedconstruction. The turbine 2 is provided as usual with the customary steam-control inlet-valve and governor which latter in my improved device becomes an emergency governor, as will hereinafter appear. As shown, the steamcontrol inlet valve, commonly called the controller valve, comprises a casing 5 into which steam is admitted through an inlet 6, and which contains a balanced valve 7 having a valve-stem 8 the projecting end of which is furnished with a helical spring bracket 14, the said spring tending to hold the valve wide open. The upper end of the said lever co-acts with the projecting outer end of the spindle 15 of the emergency governor. The said spindle is mounted in an adjusting nut 16 by 'whichthe governor spring 17 is adjusted, as required. At its inner end the spindle 'co-acts' with weights 18 pivotally hung in a cup-like head 19 secured to the projecting end of the mainshaft 20 of the turbine, the parts just described being located within a housing 21.

The governor, just described, is ordinarily passive and is brought into action only in case the follow-up pressure regulator for some reason or other fails to act when the governor is brought into play for preventing the turbine from racing, hence its designation as an emergency governor.

At its extreme upper end the governorlever 12 has an extension 2 2 engaged by the lower end of a regulator-lever 23 forming a feature of my independently organized follow-up pressure regulator. The said lever 23 is hung upon a pin 24 located within the lower end of a chambered spacing-member 25 the lower end of which has an opening 26 through which the said lever depends. The

short arm 27 of the lever enters a circumferential groove 28 in a floating diaphragm or operating-head 29 suspended, as it were, by and between diaphragms 30 and 31. Thus the left hand end of the head is secured to the diaphragm 30 by a washer 32 and nut 33, while the right hand end of the head is secured to the diaphragm 31 by a washer 34 and nut 35. The diaphragm 30 has its edges pinched between the spacer 25 and a water-chamber head or cap 36, while the diaphragm 31 has its edges pinched between the member 25 and the steam-chamber casing 37. The head 36 and the casing 37 are drawn together so as to pinch; the diaphragms 30 and 31 between them and the opposite faces of the spacing member 25, by means of bolts 38. The space within the head or cap 36 forms a water-feed boilerpressure chamber 39 from which a small pipe 40 leads to the boiler water-feed line. On the other hand, the casing 37 provides a steam-pressure chamber 41 from which a small pipe 42 leads to any suitable point in the steam line. Under this-construction,

the outer face of the diaphragm 30 is always exposed to the pressure of the boilerfeed line, while the outer face of the dia-' phragm 31 is constantly exposed to the, steam pressure.

The chamber 39 is always filled with water from the boiler feed, while the chamber 41 is constantly filled with condensed 1 water from the steam line, the condensed water in the chamber 41 transmitting the pressure of the steam line to the diaphragm 31 but protecting the diaphragm 31 from being injured by the live steam.

For the purpose of setting the followup regulator to maintain a predetermined excess of pressure in the boiler-water feed line over that in the steam line, I employ a helical spring 43' located within the easing 37 and impinging at its inner end against the washer 34, being positioned by the nut 35. The outer end of the spring encircles a flanged seat 44 located within the outer end of the casing 37 p and engaged by an adjusting screw 45 furnished with roved apparatus,

to set the springneoe oos of boiler feeding in any given situation. The predetermined excess of water pressure may be varied, let us say, "from 5 .to 65 pounds above any steam pressure whatever that may be. This excess of water ressure ensures the feeding of water to the iler under any conditions of steam pressure therein without flooding the same. Thus, when the spring is once set, the steam pressure may vary.from 20 to 200 pounds notwithstanding which the pressure in the boiler water-feed line will always exceed the steam pressure by the predetermined excess to which the said spring has been set so that the water will always flow into the boiler at a uniform rate but without -ever flooding the same, since the excess pressure remains constant and ensures the injection of a uniform amount of water into the boiler at all times. 7

Suppose that the steam boiler is operating under a uniform load. Now if an additional load is suddenly imposed upon it, or .if the 'fire gets low or needs coaling, the steam pressure will fall, calling for the production of more steam to take care of the additional load. As the steam pressure falls, the effect of it is immediately felt in the chamber 41, reducing the pressure on the dia hragm .31 and allowing the boiler watereed pressure in the chain ber 39 to act against the diaphragm 31 and correspondingly move the suspended diaphragm head 29 from left to right with the effect of rocking the lever 23, the move ment of which is transmitted through the governor-lever 12 and the valve-stem 8 against the tension of the spring 9, so as,

to act uponthe balanced valve 7, and reduce the amount of steam supplied to the turbine the speed of which will be correspondingly reduced so as to lower the water pressure in the boiler water-feed line to the same extent that the steam pressure has fallen and prevent the flooding of theboiler. Th s reduction of water-feed pressure is so far resisted by the spring 43 that it never falls below the predetermined excess of pressure at which the apparatus was initially set so that even with the reduced steam pressure in the boiler, the

excess of water pressure remains unchanged. As soon as the steam pressure is restored, either by the removal of the load or by increased firing, the restored steam pressure is felt in the chamber 41, causin the diaphr from right to left wit the aid of the spring 43, whereby the levers 23 and 12 are oppositely operated so as to permit the spring 90f the balanced valve 7 to act and increase the amount of steam sup lied to the tur bine. The increased spec of the turbine, builds up the pressure in the boiler water- ,feed so as to Keep it steadily in advance In head 29 to move.

of the steam pressure to the predetermined extent represented byethe setting of the spring 43. r

It will thus be seen that with my improved apparatus, the boiler water-feed pressure is automatically varied to' the'same extent that the steam pressure varies, whereby the boiler is prevented from being flooded or starved, but at the same time the boiler water-feed is always maintained, at suflicient excess of pressure and no more over the steam pressure, whatever that is at any given time, to ensure the feeding of water to the boiler at a uniform rate. Thus the work of feeding the boiler is done at maximum efiiciency because my improved device varies and controlsthe speed of the pump so as to produce the important result that no more work is done by'the pump than is necessary.

A variable speed motor may be used to drive. the centrifugal pump,

which may be varied in the same manner,

' by substituting a rheostat held normally in the fast position by a spring or weight, for the controller valve of the steam turbine.

I am aware of the fact'that pressure-actuated regulating deviceshave been used to control the steam admission valves of reciprocating pumps for boiler feed; but so .far as I know, such devices have been rigidly connected or linked to the controller valve for the purpose of both opening and closing the controller valve; whereas the apparatus above described operates on the controller valve or rheostat only in one direction, in

opposition. to the spring or weight which tends always to hold the valve or rheostat in the open or fast posi tion; and thereby establishes and maintains an equilibrium of the forces produced by pressure and revolution; and my described regulating and governing devicesaact inde pendently of each other, neither being restrained or op osed in any manner by the other; In the oregoing description, I have usedthe colloquial term. fol ow-up pressure-regulator which in the claims will be replaced by the more accurate name pressure-controlled speed-variator.

I claim 1. The combination with a centrifugal pump, of a motor therefor, a motor-controller, a spring tending to open the same, a low-speed variator responsive to an adjustable differential ressure acting throughout a wide zone of absolute pressures, a high-speed governor automatically alternately controlling and relinquishing control of the motor in response to changes-1n the and operative connections between,

system,

the said low-speed variator, high spe'ed governor and motor c'ontroller which permit I the speed of ernor to act independently of each other uponthe motor-controller.

2. The combination with a centrifugal pump, of a steam turbine motor therefor, a throttle-valve co-acting with the said motor, aspring functioning solely to' open the said throttle-valve, a low-speed variator responsive to an adjustable differential pressure acting throughout a wide zone of absolute pressures, a high-speed governor automatically alternately controlling and relinquishing control of themotor 1n re-- sponse to changes in the system, and opera tive connections between the said low-speed Variator, high-speed governor and spring opened throttle-valve, the said connections being of a character to permit the lowspeed variator and the high-speed governor to act independently of each other to compress the throttle-valve spring.

3. The combination with a centrifugal pump, of a motor therefor, a motor-controllernormally tending to, open, a lowspeed variator adapted to respond to an adjustable differential out a .wide zone of absolute pressures, a, ,high-speed overnor automatically alternately contrtfiling and relinquishing control of the motor in response to changes in the system, and operative connections between the said low-speed variator,high-speed governor and motor-controller, including two levers constructed and arranged to be conjointly operated by the variator to close the motor-controller, and to permit oneof them to be independently operated by therhighspeed governor to close the motor-controller.

4. The combination of a centrifugal pump,

of a motor therefor, 'a motor-contro spring for opening the same, a low-speed .variator responding to an adjustable differential pressure acting throughout a wide zone .of. absolute ressures, and including a water-pressure iaphragm, a steam-pressure diaphragm, a head connecting the said dia hragms, a spring acting u n said head an adjustable ,in tension for' alancing the pressure acting throughler, a

excess Water-pressure,v and means connectunrestrained by the said low-speed-variator to close the said motor-controller.

In testimony whereof, I have slgned this specification in the presence of two subscribing witnesses.

" HENRY B. LEE;

Witnesses:

ELIZABETH F. BROWN, FRANK J. CoNNoR.

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