US1904443A - Steam plant - Google Patents

Description

H. GLEICHMANN STEAM PLANT Original Filed Aug. l5. 1928 April 1s, 1933.

ik N w Patented Apr. /18, 1933 .UNITED STATES HANS GLEIGHMANN, or FALKENHAIN NEAR srANnAU, GERMANY, AssreNon 'ro SIEMENS-SCHUCKERTWERKE AKTIENGESELLSCHAFT, OF GERMANY, A CORPORATION OF GERMANY BERLIN-SIEMENSSTADT,

STEAM `PLANT Original application led August 15, 1928, Serial No. 299,801,7.and in Germany June 27, 1928. Divided and this application led January 4, 1930.V ySerial No. 418,511. 1'

In plants of this character, especially in cases where highv steam pressures and temperatures are employed, the feed water purity for the high pressure steam generator is by far more important, especially in cases of purely tubular steam generators, than it was heretofore with the ordinary low pressure and low temperaturel drum boiler, because in tubular boilers the impuritiesare more likely to impair the eiiiciency and correct operation of the` boiler. These conditions have suggested to the art the division of the steam generation for the high and low pressure sections of the prime mover into two distinct stages, so that the steam discharged from the high pressure prime mover is not directly delivered into the low pressure section or sections of `the prime mover system, from which latter the condensate might be returned to the steam generator in impure condition. .Between the high and low pressure sections of the prime mover system is then interposed a steam transformer in which the temperature of thehigh pressure steam discharged from the high pressure prime mover is utilized for generating lowpressure steam for the low pressure section of the prime mover system which latter constitutes thereby an entirely independent medium circulating system. This avoids the contamination of the high pressure steam generator water by the low pressure steam consumers, and permits the return of the high pressure steam condensate directly to the high pressure steam generator. The thermodynamic losses which are suffered in a system of this character are by far outweighed by the great advantages gained in the pureness of the feed water for the high pressure system, and besides by the judicious employment of mixing condensers in the low Vpressure steam system, instead of surface condensers, `thermal losses suffered in the high pressure system are practically retrieved in the low pressure system. This is true, because in mixingconden'sers Vthe eiiiciency and the vacuum are greater than in surface condensers, and in addition the first cost and maintenance cost of a mixing condenser,whichpontains only simple sprays, are both considerably l l lower than those of surface condensers.

A steam generating plant of this character and involving the above-mentioned general ideas is disclosed in my copending application, Serial No.4 299,801, led August 15, 1928, of whichy the ypresent application is adivision.

This presentapplication deals'with some particular improvements onthis character of plant, based yon the following consideration.

The interposition of va steam transformer or heat exchanger alone between the high pressure and low pressure sections of the prime mover system, such as is suggested in the aforementioned yparent application, does not complete the measures necessary for eiiiciently solving the feed water problem for-high pressure and high temperature steam' generators. In particular ,with the use ofpurely tubular steam generators, it must be taken into account that the feed water vcontains dissolved minerals whichareapt to vcrystallize during the steamv generation, .and the steam `is apt to carry'these crystals along and deposit them in the generator;` tubes where theiraccumulation is likelyV to, danfeo gerously reduce the cross-section 0fv the l tubes, and in some cases isapt tolclogthem altogether. Such crystals are also llikely-to cause considerable wear of the turbine buckets.

The above disadvantages are overcomeaccording to they present invention by interposing :into Vthe high pressure circulating system, and directly ahead of the steam transformer, a steam purifier, which constitutes a purifying chamber filled' with a suitable Washing liquid, and in which'th-e steam exhausted from the high pressure prime mover .is condensed and regenerated on the surface of the liquid before it enters the steam heat exchanger. This washing process dissolves the crystallized 'mineral matter which 'might i be contained -in the steam, so that it can be drained ofi' from the washing chamber, and thereby removed from lcirculation system.

If reciprocating prime movers are used-in the highpressure section of the prime mover system, besides a L mechanical or, chemical sump 13.

Referring tothe drawing, 1 represents the high pressure high temperature steam gen` erator which delivers by way of a steam main 3 steam to the prime mover lV which, in .this

case, has the form of'a reciprocating piston machine. The steam 'is discharged from the low pressure stage 76 of prime mover 4, and after passing through an oil .separator 78 is discharged through a conduit 84 into a' steam washing devicel82 of the steam regeneration type. This device functions by condensing the steam supplied to it in the washing liquid, and by regeneratingit on thesurface of the liquid. The steam thus regenerated is free from all impurities, including'mineral salts, which the generator .steam might have carried along, and which remain dissolved in the washing liquid. As awashing liquid 'the samekind of liquid is used as the one from which the vapor is generated 'in they lhigh pressure system; inthe present case ofy high pressure steam generation, water would be used as a washing liquid. Water as a steam Washing liquid is well knownin theart. The'puriiied steam passes from this washing chamber by way of a conduit 85 into the steaml heat exchanger or steam transformer 83 inwhich the heat exchanger 12 is disposed "through which the high pressure high temperature exhaust steam passes, and

whichheats the water contained inthe steam transformer, thereby generating low prese sure steam.v

' Preferably the steam washing chamber is made a part of the steam transformer fby dividing the transformer drum by means ofa partition wall 81 into two compartments,

fone of which forms the steam washing chamber, and the other the steam transformer chamber. c s

v The water from which the lowvpressure steam is generated in the steam transformer is supplied fromla sump 13 through a. pump 14, and by way of feedv water heaters 25,

into the steam transformer, and the second-Y ary steam( generated in vthesteam transformer is supplied by way of secondary main 21 to a low pressure steam consumer which is in this' case represented `by a lovv pressure turb1ne48. The exhaust steam from `this turbine isc'ondensed'in 'a mixing condenser 52 which is supplied'fwith cold water through pump 53, the condensate from this condenser flowing by way ofv discharge ypipe 54 into the The condensate discharged by the heatexi changer 12 of the'steam transformer Vflows generating systemaccording to my inthrough the pipe 17 into the feed water heat' er 25 aforementioned, and thence through pipe 26 into the sump 18 from which it is delivered by feedY pump 19 into'the high pressure steam generator 1, thereby establishing an entirely separate circulation independent .of the klow pressure steamA generating circuit. y

Aside from heating the feed water for the steam transformer .by .'means. of. ftheY condensate discharged from the heat exchanger 12, this feed water is further heated to a suitable higher temperature by means of interstage steam tapped between the.' stages L75 and. 76of the highpressure prime mover 4;, which after passing through an oil separato'r "86 first serves for sup-erheating. the

secondary steam generated in the steam transformer through a coil 42 disposed in the dome 68 of the steam transformer. From coil 12 the steam passes through *pipev 24 into the feed water heater 4 5, whence itis discharged s through a pipej87vby way of acontrol valve 88 'into the'steam washing chamber.V 'A check valve 100is provided near the steam entrance intoth-e washing chamber, in order to prevent the washing liquid from entering feed water heater 45 in case'the pressure in the Washing chamber exceeds that in the water heater 41:5.`

Aside Vfrom feeding "the steamwashing chamber with exhaust steam"'from prime mover 4, an additional supply of steam may be delivered :directly from mainf by 'Way' of a control'valve 90 which is controlled by a pressure responsive device 92 connected t0 main 3 such that -asthe` pressure in steam main increases valve opens further and delivers more steam into the steaml washer and steam transformer. Y I

For contr-olling the feed' water supply to steam transformer 83, a valve 32 is provided in the feed' water line between pump 14:V and feed water' heater 25,y which valve is controlled by fa `pressure responsive -device 34; responding to pressure variations in the sec-V ondary steam main 2l, so that when theV pressure in the latter decreases, more feed water is supplied to the transformer and when it increases, the reverse occurs.

',Likewise, the pressurev variations in sectrolling the fuel supply to steamv generator -TIO 1 by means of'pressure responsive device 38 connected lto the secondary' main and controlling fuel supply Valve, 104.- such-that when the secondary steam pressure decreases the fuel supply increases and when the pressure increases the fuel valve is actuated thereverse way. Y, v 'l lclaima` A high and lowy pressure vapor power yplant having a high pressure circuit.' for the operating medium including a high pressure vapor I generator, a high pressure prime mover sup liedfwith vapor from the/generator, a

IT15 ondary steam main 21 are utilized for con- Y vapor transformer of the indirect heating type connected at its prim-ary side to the exhaust side of said high pressure prime mover, and means for returning the condensate from the primary side of the vapor transformer to said generator, the low pressure medium circuit including the secondary side of said vapor transformer and a lon7 pressure vapor consumer, the high pressure 10 medium circuit including a vapor Washer of the direct vapor regeneration type containing a Washing liquid of the same kind as the liquid from which the high pressure vapor is generated, said Washer being interposed l5 between said prime mover exhaust and the primary side of said transformer, whereby through the regeneration of vapor from said Washing liquid purified vapor is delivered to said transformer and purified condensate is returned to said generator.

HANS GLEICHMANN.

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