US1790154A

US1790154A - Feed-water heater

Info

Publication number: US1790154A
Application number: US229372A
Authority: US
Inventors: Alexander T Kasley
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1927-10-28
Filing date: 1927-10-28
Publication date: 1931-01-27
Anticipated expiration: 1948-01-27

Description

, 1931 A. T. KASLEY 1,790,154

FEED WATER HEATER 'Filed Oct. 28, 1927 WITNESS INVENT I A-T- Kqsley 7 BY Q1 .03 i M ATTORNQEY Patented Jan. 27, 1931 UNITED STATES rnTENr OFFICE,

ALEXANDER '1'. KASLEY, or moonns, .rmmsxnvmm, assmnoa T wns'r'menousn nmcrmca, -mnu mcruamecompany, A conrona'rmn or rms nvamn FEED-WATER. HEATER a l cation filed bctober 2 ,113. Serial Ho'.229,372i

My invention relates to feed water heating systems, and more particularly to systems embodying regenerative, heaters, and it has for an-object, to improve the efliclency of apparatus of tlus character.

\Vhere regenerative heaters are used in connectionwith a steam power installation, the thermal efficiency for the steam whlch passes through the heaters if, theoretically at some of the available energy 10 leash 100%.

of the steam from the boiler is abstracted 1n the production of mechanical energy in the prime mover. The steam which is then bled to the feed water heater is condensed to water at its own temperature, thus giv ng up its latent heat, to the feed water, and the drains from the heater being returned to the feed water, there is, theoretically, no thermal loss.

Moreover, considering the quantity of steam, the. size of the apparatus required, etc, it is, as a general proposition, more economical toheat the feed water in successive stages; Such an arrangement requires, either a separate-pump between each two of the successive stages, or one pump which is capable of passing the feed water through all of the various-stages.

Inthe latter case, all of the heaters must be designed to withstand the pressure created by the single pump, which in many cases is as high as 600 pounds per square inch. Ob-

viously,-this considerably increases the cost of the heaters for the lower pressure stages.

on the other hand, where separate pumps are used, there is a saving in the cost of the heaters, but an increased cost dueto the additional pumping apparatus required,

In any event, whether the feed water he heated in several stages, or in a single stage,

some form of pumping apparatus has heretofore been required for translating the feed water through the heating system. I have found that it is possible to do away with the 4. various forms of pumping apparatus and to utilize the energy in the heatin fluid, as the bled steam, for translating the feed water. -More particularly, therefore, an object of my, invention is to providea feed water heating system of the type described, which'shall embodymeaus for using successive streams of bled steam for translating the feed water in the absence sible. Apparatus embodying the features of my invention is shown in the accompanying drawing, forming a part of this specification,

- and wherein the single figure is an elevation;

- these stages.

The higher pressure stages are provided with valves which are timed to open intermittently andin the proper sequential order. to utilize, to the fullest extent, the expansive force of the heating fluid and the force of gravity for passing the heated fluid through the system. Of course, the valves may be omitted altogether and the pressures between all the stages may be balanced by columns of liquid, but asthis might require a column several 'hundredfeet high to balance the pressurein the higher pressure stages, I prefer I the combined arrangement as outlined above. Referring now to the drawings for a better understanding of my invention, I show a .prime mover, such as a bleeder turbine 10, ar

ranged to exhaust to a surface condenser 11, which is provided with a hotwell 12, and with 90 of other means, so far as posan extraction mp 13 for removing condensate from the otwell.' The extraction pump heating system.

A series of any suitable number of cham-.

bers, such as the tanks 16, 17, 18,19, 20, 21, 22, 23, 24, 25, 26 and 27, are arranged at successively greater elevations so that the, condensate may pass by gravity from the connec-. tion 14 through these tanks in series. Bledsteam is supplied to the respective tanks through the

connections

28, 29, 31,- 32, 33, 34, 35, 36, 37, 38, 39 and 40, proceeding from.the low-pressure end of the turbine in the order named.

Each of the

connections

28,29, and 31 to i255 provided with a perforated end piece 28',

and 31' to 40' respectively. These end pieces extend well into the various tanks and have their inner ends closed,'while their respective outer ends are connected to receive motive fluid from the various bleeding connections. By virtue of the perforations and the closed inner ends of these pieces, it is as sured that motive fluid will be difiused through the liquid media in each tank and thus, efliciently heat the same. Preferably,

- these stages. The tanks 16, 17 and 18 are these perforated connections are also arranged as near the bottoms of the respective tanks as possible in order to producemaximum heating.

- In the form of the invention shown, steam is bled through the

connections

28, 29, and

31 continuously and, as the pressure differences between these lower stages are relatively small, it is possible to balance the pressures between the tanks 16, 17 and 18 by means of relatively short columns ofliquid, such as the feed water, and thus obviate, the necessity for valves for controlling the heating in similar in all respects, with the exception that the tank 18 is made somewhat larger than either the tank 16 or 17 for a purpose to be described later.

A circular cup member 41 is disposed within the tank 16 below the depending end of the connection 14, which extends through the upper wall of the tank. The brim of the cup 41 is arranged to project slightly above the lower end of the connection 14 so as to provide a liquidseal toprevent steam, which is passed into this tank through the connection that it ma be heated by steam which passes into this 0 amber through the connection 28. The tanks 17 and 18 are provided with'cup 13 is arranged to deliver the condensate through the connection 14 to the feed water members 41 and with spray plates 42 for similar purposes.

A connection 43 extends from the bottom of the tank 16 into the upper portion of the tank 17 and within the brim of the cup 41. A

similar connection 44 extends from the bottom of the tank17 through the upper portion of the tank 18 and within the brim of the cup 41 in that tank.

As the relative difference in pressure of the steam in the

connections

28 and 29 will be relatively small, it is possible to balance this difference in pressure by a relatively short connection, such as is provided by the connection 43 between the tanks 16 and 17.' The difference in pressure between the

connections

29 and 31 would probably be greater, and for this reasonthe connection 44 between the tanks 17 and 18 'is made somewhatv longer than the connection 43, so as to provide an adequate column of liquid for balancing this pressure and for assuringproper'fiow between these stages.

It will be obvious that the three stages thus far described may constitute a complete feed Water heating s stem, and that a complete system of this kind may include more or. less than three stages as shown, and need not necessarily be supplied only with lowpressure steam, but, of course, if the bleed points are farther apart, .or higher pressures are encountered, the respective tanks would be spaced farther apart and the intervening connections, such as the connections.43 and 44 would be lengthened a suflicient amount to provide adequate columns of liquid to compensate for the particular differences in pressure between the respective stages. With relatively high pressures, such columns would attain a considerable height, and for this reason I prefer to use feed heaters of this type only in connection with the lower stages and to'provide valves for controlling the flow through the higher pressure stages.

Communication between the tanks 18,19, 20, 21, 22, 23, 24, 25, 26 and 27 is'controlled by the magnetic valves 46, 47, 48, 49, 51, 52, 53, 54 and 55 and the passage of the heating fluid, such as bled steam, into the tanks 19 to 27 inclusive is controlled by the magnetic valves 56 to 65, inclusive, which-are disposed in the bleeding connections 32 to 40, respectively.

In theoperation of the apparatus thus far described, condensate from the condenser is supplied, by the extraction pump 13, through the connection 14 into the uppermost tank 16, from whence it may pass by gravity through the tank 17 and into the tank 18.

In passing through these tanks it is heated by steam supplied through the

connections

28, 29 and 31, respectively.

The flow of the feed water thropgh the tanks 19 to 27 is intermittent. Considering only the tank 19, the valve 46 is opened so that this tank may be filled from the tank 18.

The valve 46 is then closed, and, the .valve 47 remainingngllosed, the steam valve 56 is opened to t steam to the tank 19ffor heating the-feed'water therein. After a 47 to the tank 20, so that the latter may be' filled. The steam'valve 56 is closed after the tank 19 is partially emptied. The water valve 47, however does not close until the tank 19 is completely empty, so that all liquid media may drain to the tank 20 where the pressure is very low.

The cycle of operation for each of the tanks 19 to 27 is the same as that just described with reference to the tank 19, but as some of the tanks are empty while others are filled, it will be apparent that the cycle of events occurs s1- multaneously only in alternate tanks. Considering the operation of the tanks 19 to 27 as agroup, it will be observed that the flow from the tank 18 is controlled by the magnetic valve 46,,which is opened at the same time that valves 48, 51, 53 and are opened, so

that liquid media may pass from the tank 18 to the tank 19, from the tank 20'to the tank 21, from the tank 22 to the'tank 23, from the tank 24 to the tank 25, and from the tank 26 to the tank 27. At this time the magnetic valves 47 49, 52, 54 and 55- are closed. This per.-

'mits the tanks 19, 21, 23, 2 5 and 27 to be filled with condensate and, by opening the magnetic valves 56, 58, 61, 63 and 65, bled steam may be supplied for heating.

- This being accomplished, the magnetic valves 56, 58, 61, 63 and 65 are closed and the magnetic valves 47 49, 52, 54 and 55' are opened so as to permit the condensate to pass into the next succeeding of the remaining chambers, namely, the chambers 20, 2 2, 24, 26 and through the valve 55 to the boiler feed pump. The process is then repeated in these newlyfilled chambers and,' after the heating has been accomplished,.the contents are discharged into the next succeeding chambers, and so on, until the feed water has passed completely through the various tanks. Thus it willbe seen that steam is bled continuously through the

connections

28, 29 and 31, and is bled intermittently through the alternate ones of the connections 32 to 40, inclurive.

It will be obvious, however, that by providing two or more stacks of tanks, such as the stack composed of the tanks 19 to 27, inclusive, the steam may be bled continuously from all the bleed points, should this be considered desirable.

In order to provide for automatically controlling a system of this character, I provide a small motor which, by means of the worm:

only be opened when 71, is adapted to rotate the worm wheel 72 and thus, to cause the brush 73, which is carried by the shaft of the worm wheel 72, to rotate in the direction indicated bythe arrow, and

tacts 76, 77 and 78, respectively. Electrical energy is supplied from the positive line 81, through theconnection 82, to the brush 73 in any suitable manner, as by means of sliprings or the like (not'shown). The motor 70 may' also be supplied with electrical energy from the positive line 81 through the connection 83, and may be connected with the nega-' tive line 84 through the connection 86.

The magnetic valves 46, :48, 51, 53 and 55 are arranged in parallel between the connection 87, from the arcuate contact 7 7,'and the .connection 88 to the negative line 84. Hence,

these valves are opened while the brush 73 cbmpletes the circuit through the arcuate contact- 77. l

v Likewise,-.the magnetic valves 47, 49, 52, 54, and 55' are in parallel between the connection 89,-from the arcuate contact 76, and the connection 91 to the negative line 84. Similarly, the magnetic valves 56, 58, 61, 63 and 65 are in parallel between the connection 92, from the arcuate contact 74, and the connection. 93 to the negative line 84. The magnetic valves 57, 59, 62 and'64 are arranged in to wige against the stationary, arcuate cona like manner between the arcuate contact 7 8 and the-negative line 84 by' means of the con nections 94 and 96, respectively.

It willbe obvious, therefore, that the re-'- spective valves in these various groups will the brush 73 completes the circuit through that stationary, arcuate contact which is associatedv with each group of valves. I With .the motor 70 operating at a constant speed, the length of the stationary contacts determines the time that the various valves may remain open, and it will be observed that i the contacts 74 and 78 are symmetrically ar rangedandare of greater length thanthe contacts 7 6-and 7 7. which are likewise symmetrically disposed.

It will also be observed that the rotating. brush 73 will complete the circuit throu h the steam valves controlled by the contact 74 before the circuit is made through the contact 7 6, and that the water valves controlled into the tanks, where the heating has just taken place, for the urpose of accelerating the discharge of liquid 'media from such tanks: In th1s way, it is possible to utilize theexpa'nsive force of successive streams of bled steam for translating the feed water through the system and while, of course, this feed water would tend to gravitate of its own tact- 74 are closed before the water valves which are controlled by the contact 76. Hence,

- it is assured that no pressure vwill be built up, in any of the tanks, which would tend in any way to'interfere with the flow of condensate therethrough.

Inasmuch as the contacts 77 and 7 8 are arranged in a manner similar to those just described, it will readily be seen that the steam valves controlled by the contact 78, and the water valves controlled by the contacts 77 will operate in a manner similar to that just described with reference to the

contacts

74 and 76.

\Vith the brush 7 3 in substantially the position indicated, the tanks 19, 21, 23, 25 and 27 would be filled while the remaining tanks would be empty, with the exception of tank 18,-in which, it will be remembered, water is continuously admitted and which is made larger-than the other tanks for permitting this water to accumulate in order .to compensate for the intermittent operation of themagnetic valve 46.

It will thus be seen that -I have provided a system for utilizing the force of gravity,

either alone, or in combination withthe 8X? pansive force of successive streams oflbled steam for translating feed water through a series of feed water heaters and thus, it'is possible to dispense with the various forms of pumping apparatus which have heretofore been required for this purpose.

WVhile I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof,

and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are-specifically set forth in the appended claims.

Vhat I claim is':- a 1. A feed water heating system comprising a plurality of communicating chambers arranged at progressively greaterelevations,

valve means for controlling the flow between said chambers, a passage for conducting heating fluid under a relatively low pressure to the uppermost of said chambers, inde endent passages for conducting heating fiui to suecessive chambers at successively greater pressures, other valvemeans for controlling the flow through each of said passages, and control means for operating the various valve means for periodically admitting heating fluid to alternate chambers and for releasing the barometric column between chambers liquid media from the respective alternate chambers to the respective succeeding chambers during the admission of heating fluid t0 the respective alternate chambers.

2. In a feed-water heating system, the combination of a plurality of chambers arranged successively at greater elevations,'said chambers including an upper group and a lower group, means for supplying water continuously to the uppermost chamber of the upper group and from the latter in-succession to the remaining chambers of the upper group, means for continuously supplying steam at a range of low pressures to the chambers of the upper group, the steam being supplied to the chambers of the upper group considered downwardly and successively at successively greater temperatures and pressures and-the chambers of the upper group being, spaced apart successively distances such that the barometric column between chambers counterbalances or compensates for the greater pressure of steam entering a following chamber, means providing for the passage of waterfrom the lowermost chamber of-the upper group downwardly and intermittently throughthe chambers of the lower group, means for supplying steam to the chambers of the lower group considered downwardly and successively at successively higher temperatures and-pressures after the latter chainbers -are filled and during at least the first portions of the periods of discharge therefrom. v

3. In a feed-water heating system,. the 100 combination of a plurality of chambers arranged successively at greater elevations, said chambers including an upper group and a lower group, means for supplying water continuously to the uppermost chamber of 1 5 the upper group and from the latter in succession to the remaining chambers of the upper group, means for continuously supplying steam at a range of low pressures to the chambers of the upper group, the steam being sup- 110 plied to the chambers of the upper group considered downwardly and successively at sucspaced apart successively distances such that c ounterbalances or compensates for the greater pressure of steam entering a following chamber, a passage for connecting the lower portion of the lowermost chamber of the upper group to the upper portion of the uppermost chamber of the lower group, passages for connecting the chambers of the lower group in series, each of'such connect-j ing passages communicating with the lower portion of a preceding chamber and with the upper portion of the succeeding chamber, a discharge passage communicatingwith the lower portion of the, lowermost chamber, valves in all of said passages, operating 13c I said the admission of steam to the chambers of the lower group after they are filled from,

preceding chambers and during at least the first portions of dischar e therefrom.

4. In a feed-water fieatin system, the combination of a pluralit o chambers arranged at successively igher elevations, means for supplying water to the uppermost chamber, means providing for the intermittent passage of water downwardly through the followmg chambers, means for supplying heating medium to the uppermost chamher, and means for intermittently supplying heating medium to said following chambers after the latter are filled with water and during at least the first portions of the periods of discharge therefrom and for alternately interrupting the supply of heating medium when said chambers are being filled with water, said heating medium supply means supplying heating medium to downwardly successive chambers at successively higher temperatures.

5. In a feed-water heatin system," the.

combination of a plurality oh chambers arranged at successively r elevations, means providing for the intermittent'pase sage of water downwardly through the chambers, means for intermittently supplying heating medium to the. chambers after the latter are filled with water and duringlat least the first portions of the periods of discharge. therefrom and for alternately interrupting the supply of heatmg medium when said chambers are being filled with water, said heating medium supply means supplying heating medium to downwardly successive chambers at sively higher temperatures' 6. In a feed-water heatin system, the

succes conduitsezgcept the conduit supplying the uppermost chamber, and meansior controlling the operation of the conduit valves so' that steam is admitted to the chambers after 7 being filled with water from preceding 7 chambersand during at least the first portions of discharge therefrom.

In testimony whereof, I have hereunto subscribed my name this 17th day of October, 1927.

' ALEXANDER T. KASLEY.

combination ofa plurality o chambers arranged in superposed substantially vertical relation, means for' supplying water to the upper chamber, passages for connecting the chambers in series, an outlet passage for.

the lowermost chamber, valves arranged in passages, means for" operating the valves so that water is'passed through the chambers intermittently from' chamber to chamber, conduits for supplying heating medium to the chambers, said conduits being arranged to supply heating medium to downwardly successive chambers at successively higher temperatures, valves in all of said,