US1392003A - Automatic control of steam-condensing plants - Google Patents

Description

H. FOTHERGILL.

AUTOMATIC CONTROL OF STEAM counensme PLANTS.

'APPLICATION man AUG-8. m9. 1,392,003, PatentedSept. 27,1921.

4 SHEETS-SHEET I- i nvenio'r' H. FOTHEBGILL. AUTOMATIC CONTROL OF STEA'M CONDENSING PLANTS.

APPLICATION man AUG-B. 191s.

4 SHEETSSHEET 2- J we??? H. FOTHERGILL.

AUTOMATIC CONTROL OF STEAM CONDENSING PLANTS.

APPLICATION men AUG-8. 1919.

1,392,003, PatentedSept. 27,1921.

4 SHEETS-SHEET 3.

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H. FOTHERGILL.

AUTOMATIC CONTROL OF STEAM CONDENSING PLANTS.

' APPLICATION HLED AUG-'8 m9.

1,392,003. PatentedSept. 27,- 1921.

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ing receiver.

U E QSTAT'ES TENT E IQE-a HARRY FOYTHERGILL, or WESTMINSTER, LONDON, E GLA D.

AUTOMATIC CONTROL or STEAM-CONDENSING PLANTS.

To all whom itmay concern:

Be it known that I, HARRY F0THnRo1LL,'a subject of the King of-GreatBritain, residing at 3. Central Buildings, Westminster, London, England, have invented-Improvementsin and Connected with the Automatic Control of Steam-Condensing Plants, of which the followingis a specification.

This invention relates to improvements in and connected .with the automatic control of steam condensing plants in which, a valve operated automatically by the steam pressure available as a consequence of the operaillustrated embodiments of my. invention diagrammatically, Figure. 1 being a diagram ,2 .of an apparatus suitable for use .rocating engines,

tion of the main engine is employed to control the admission of cooling medium tothe condenser. 'l I 'In the caseof reciproc'a'tingengines for instance [operating in conjunction with steam condensers of that general character where a steam jet or jets is or are employed for extracting aerated vapor from the condenser and delivering it to a receiver or secondary condenserwherein it is condensed and from which the airis extracted by means of an air pump driven fromthemain engines, it is obviously undesirable for the steam jet or jetsto continue operating when the main enginesand asa consequence the air pumpam not running. Nor is it delarly-to Fig. ,1 which shows onev form of my sirablej-in such a case to continue 'the circulation of. condensingv Water to the condens- In the case of steam rturbines' the circumstances are somewhat diffei'entsincethe air withdrawing and discharging apparatus 11s usually I operated continuouslyand inde pendently of the turbine, but here again it is necessary to controlthe temperature 'by bypassing 'a quantity of water frorn' the tank or condensing receiver into. which the steam jet or jets discharge into the mainlcond'enser.

Moreover, "in such plants, condensate 1s usually withdrawn fromithe main condenser by arotary pump, and in order to provide for the satisfactory Working of such pumps it is desirable to keep them continuously supplied with water,-aw des1deratum which can be attained with apparatus in accordance with my invention.

The object ofmy inven an improved arrangement constituting a steam condensing plant wherein the temperature of thefauiriliary.condenser is con-' trolled by automatically b'y-passmg a quan tity-of water from thetank or condensing Specification of Letters Patent. Patented Sept.

Application filed August a, 1919. Serial No. 316,186.

tion is to provide receiver into which the steam jet or jets discharge, into the main condenser.

1 A steam condensing plant according to this invention comprises a main condenser,

an auxiliary'condensing device into which,

condensate from the main condenser is dis only when the engines are, running for con- 3 trolling the flow of water insaid pipe,-

.In the accompanying drawings '1' have ,F'g; 2 is adiagramof one form of device I forv application to steam turbines, Fig. ,3 is an enlarged view of; employed in'thiscase, I

Fig. 4is a similar view of a modified apparatus, I:

- F'g. 5 is anenlarged view of thevalveemployed' in this modification and Figs. "6 and 7 are similarly? views of a furthermodified apparatus and the valve, employed therein respectively.

Referring to-these drawings'and' into acondensing iBCelVBI. from which the" contents'are withdrawjn :by an air pump driven" from the main engines, the numeral 1 designates a piston adapted to :operate a valve 2 controlling theisupply ofjsteam to the .stea'mjet ejector and a valve-13 \controlling the supply, of water to ;a;con-

densing receiver into which the steam .jet e ector discharges in accordance with known practice. Thesevalves are normally closed 'by springskland 5 and a lost motion con-,,

the valve 4 nection" 6- is,-;provided betweenjthe two valves so that in operation the valve 3 will be openedslightly in advance of the valve 2 water to-the condensing rece ver. being avail-v ..able to condense the steam l delivered to the receiver by the ste am jet. .;A pipe 7 conv as to insure the supply of condensing running. For instance, in a triple expanslon steam engine this pipe 7 may convenlently be connected to the intermediate receiver. The exhaust or other steam supply for operating the steam jet enters the casing of the valve 2 as indicated by the an row 9 and the steam passes to the steam jet as indicated by the arrow 10 and the water from the air pump discharge, which water.

is usually condensate from the main condenser passes into the valve casing as indicated by the arrow 11 and passes out to the condensing receiver as indicated by the arrow12.

In operation when the main engines are running, steam from the intermediate re ceiver or other suitable pressure: supply passes to the space 13 above the piston 1, as-

suming of course, that the valve 8 is in open position and the steam pressure acting on condensing receiver. I

In Figs. 2 and 3 I have illustrated one form which my invention may'take 'a-s applied to the controlof a by pass valve be tween the main condenser and an auxiliary condensing device which'in this example is shown as a tank. Referring to these figures, the main condenser is indicated at 1 1; and aerated'vapor is withdrawn from this condens er by the steam jet'ejector 15 anddischarged through the perforatedpipe 16 into a tank 17- to which the condensate isalso delivered by the pump 18 byway of'the pipe 17*, the non-return valve 1 9 preventing any back flow from this tank 17; A pipe "20- leads from the tank 17 to "the conden'serlel and the automatic valve illustrated in detail in Fig. 3controls the flow from the tank 17 4 to the condenser 1. ,This valve comprises a diaphragm '21l'oaded by aspring 22 and connected to operate theby: pass valve proper 23. -A pipe2 1 leads fromt'heturbine casing '26 or from elsewhere where the pressure varies with variations in load on the turbines, such for instance as-thesteam supply between thethrOttle valve and the turbines, to the chamber 25 above the dia- ,phragm' and another pipe 27 leads from a position between-the delivery side ofpump' 18 and the non-return valve 19 to the chamber 28 beneath the diaphragm 21. This diaphragm 21"is so loaded by the spring'22 that when the turbine is starting up or 'run ning under light load, the valve isfhe'ld open by the spring assisted by the pressureof the water in the discharge pipe of the pump 18 and waterfrom the tank 17 is delivered to the condenser'll wherein it is cooled. At half load or someother predetermined load the steam pressure from the turbine casing 26 acting on the diaphragm 21 overcomes the spring and the valve 23 closes, the condensatefromthe condenser at this predetermined load being sufficient to condense the steam and aerated vapor delivered to the tank 27by the steam jet ejector 15. If for any reason the condensate pump 18 fails the non-return valve 19 will shut and a vacuum, consequentupon the vacuum in the condenserl l, will be produced in the chamber 28 beneath the diaphragm and the valve 23 will close, thus preventing flooding of the condenser. j

The arrangement shown in Figs. 4' and 5 differs somewhat from'that shown in- Figs. -2 and 3.

In this case the'first steam jet ejector 15 delivers aerated vapor to a condensing'rec'eiver 29 and asecond steam'jet ejectorBOdischarges'into the tank 17, from which water is discharged to the condensing receiver 29 by way of thepipe31 which may be provided'with a valve. The hot wa-' .ter from the condensing receiver passes by way of the looped pipe 32 to the pipe33- -which is connected at one end to the condenser-"14 and at the'other endto the suction'side of the condensate pump 18. In

' this case the diaphragm 21'is so loaded by the spring 22 that the valve 23 is held closed when-the turbine is starting anduntil half or other predetermined load is reached and the hot water from the condensing receiver 29 passes 'into the main condenser Hand is cooled, When thispredetermined load occurs, however, the pressure from the turbine casing 26, acting on the diaphragm 21 overcomes the spring and the valve opens, thus allowing the hot water from thecondensingreceiver 29 to pass to'the suction side ofthe condensate pump 18 and-be uti- -liz ed for heating up the condensate from the main condenser.

. -A further modified arrangement is shown in Figs. 6 and 7.- In this case the steam .jet ejector 15 .isin series'with a water jet ejector '34 and discharges'into :the tank 17 the .waterjet ejector being supplied with water from the tank 17 by means of the pump 35,

" condensat from the main condenser 14 be :ing deliveredto the tanklfby the pump 18as before. A pipe 36-leads from the pipe 37, leading to the water operated ejector, to the main condenser and here" again the loading of the diaphragm 21 is such as to insure the automatic valve 23 being closed at starting. 'At starting and until this predetermined load is reached water. under pressure from the pump 35, passes through the passage 35 acting on the underside of the diaphragm 21, opens the valve 23 thus allowing water to be returned by way of the pipe 36 to the condenser 14. When the predetermined load on the turbine is reached, however, the stream pressure from the turbine casing 26 assists the spring to overcome the water pressure and the valve 23 closes. If from any cause the pumps should fail it is obvious that the water pressure acting on the diaphragm 21 will fail and the valve will close thus preventing flooding of the condenser.

The piston, diaphragm or the like may be so loaded that as soon as the main engines are started, and even a small pressure applied to it, the (piston, diaphragm or the like will be cause to move, and the valve or valves or other element or elements 0perated. Or the piston diaphragm or the like may be so loaded that the movements of the valve or valves or other element or elements varies with increases or decreases of pressure, and consequently of the load on the main engine.

In cases where two or more valves are operated in accordance with my invention, said valves may be caused to open consecutively, a space of time elapsing between the opening of one valve and the opening of the next in series.

The piston or diaphragm, and the valve, may be of any convenient type, and although I have referred particularly to a turbine, it will be understood thatthe invention is applicable to the condensing plant of reciprocating steam engines.

What I claim and desire to secure by Letters Patent is 1. A steam condensing plant comprising,

a main condenser, an auxiliary condensing device into which condensate from the main condenser is discharged, a ipe leading from the auxiliary condensing evice to the main condenser and an automatic valve in said pipe controlled by steam or other pressure available only when the engines are runnin for controlling the flow of water in said pipe.

2. A steam condensing plant as set forth in claim 1 having automatic valves comprising a piston or diaphragm held in position by spring or other load until the steam pressure in an engine receiver orturbine casing reaches a predetermined value.

8. A steam condensing plant as set forth in claim 1 wherein the operation of the automatic valve is also dependent on the effective working of a pump or pumps.

4. A steam condensing plant comprising a condenser, a tank, a steam jet ejector discharging from said condenser into said tank, a pump discharging condensate from said condenser to said tank, a return pipe leading from said tank to said condenser, an automatic valve in said pipe adapted to be held open by a spring until the engine or turbine attains a predetermined steam load and means for insuring closure of said valve when said load is attained and also in the event of failure of the condensate pump substantially as specified.

Signed at London, England, this 22 July, 1919.

H. FOTHERGILL.

Witnesses:

CHARLES F. HIGGINS, P. G. Mrssnmmoox.

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