US2096215A - Device for introducing liquids into pressure vessels - Google Patents

Description

Oct. 19, 1937. L. s. TWO MEY 2,096,215

I DEVICE FOR INTRODUCING LIQUIDS INTO PRESSURE VESSELS Filed July 28 1936 LEE T WOMEY Nl ENTOR ORNE) Patented Oct. 19, 1937 UTE STATES VFEQ PRESSURE VESSELS DEVICE FOR INTRODUCING LIQUIDS INTO Lee S. Twomey, Vista, Calif.

Application July 28, 1936, Serial No. 93,045

10 Claims.

pressure.

The rationale and advantages of the invention will be evident on inspection of the attached drawing and the following description thereof in which Fig. l diagrammatically illustrates one form of the assembled device and Fig, 2 illustrates in larger scale a modified form of the bubbler plates of Fig. 1.

For illustrative purposes and without in. anywise limiting the application of the device or method, I will first describe their use in connection with feeding water at 80 0. into a steam boiler maintained at 50 atmospheres absolute pressure.

Referring to the drawing, Fig. 1, B and C are pressure vessels which may be of the same size. A is a receiver containing the supply of feed water at 80 C. A may, for example, be the hot well of a condensing system, or it may be any source of supply of water at 80 C. The vessels B and C may be placed at any desired level relative to each other and to the boiler D.

A steam boiler of the water tube type is indicated at D. This consists of a drum If), water legs H and i2 and tubes l3l3, all of which are of conventional design, the water level in the drum being shown at 23, A short connection l4 located on the top of drum ll] establishes communication between the interior of the drum and a space l5 enclosed by a truncated conical member 46, a cylindrical member l1 and a dome l8, to which is attached the steam olftake pipe l9, all being nonleakably joined and of suitable strength to Withstand boiler pressure. 7

A feed water inlet pipe 20 discharges into space I5. Below the point of feed water entry, a perforated bubbler plate 2| extends entirely across space IS, in such manner as to retain above it a pool of feed water, thru which passes steam leav-v ing drum M9 on its way to ofitake pipe 59. The steam passing upward thru the perforations is divided into a multiplicity of small streams, insuring intimate contact between steam and feed water, and also preventing the depletion of the pool thru downward passage of water thru the perforations, altho a limited amount of such a water passage does not preclude functioning of the device. The pool of feed Water overflows the upper end of downspout 22, which extends thru and above plate 2! a sufficient distance to retain a pool of desired depth. The lower end of pipe 22 extends below the water level 23 of drum 10 or is otherwise water sealed to prevent upward pas sage of steam thru the pipe. 7

Instead of the perforated plate 2i, a plate or a multiplicity of superimposed plates of other type may be used, as for. example those shown in Fig. 2, in'which 69 represents a portion of the shell enclosing the space (i5 of Fig. 1), SI and 62 are plates nonleakably attached to 68, ex-' tending across the space and provided withsteam tubes 63, each of which is surmounted'b-y a cap 64, the lower edge, either smooth or serrated, dipping below the surface of a pool of feed water on the plate. The feed water enters thru pipe above the topmost plate. Two types of watersealed downspout are shown at E6. and El, each. so located as to cause an approximately maxi 'mum travel of feed water across the plates. In-

stead of the caps of the type shown at $4, any other type designed to cause intimate contact be"- tween steam and. water may be used. A desirable result, using a simpler device, may be pro;- duced by merely causing the steam supply to im-l pinge on plates over which the feed water flows as it enters the boiler.

Returning now to Fig. 1 the space 15 need not i be limited to the shape shown. The shape will be dictated by the desire to provide a cheap and simple enclosure for the requisite bubbler plate area, which should be sufiicient to allow maximum steam output to bubble thru the pool of feed water without serious entrainment. The uniform distribution of steam flow thruout theplate area may also influence the shape of the enclosure. A plurality of enclosures in parallel may be used if a single enclosure becomes of undesirable size.

The pressure vessel B is provided with one or more perforated plates 2 located in its upper portion and adapted to distribute water discharged thereon into a spray falling in B or with one or more spray nozzles or other devices located in its upper portion and adapted to precipitate a spray or rain of water downwardly in B. V

The pressure vessel 0 is provided with one or more bubbler plates 25 located in its upper portion, each provided with water-sealed downspout 25. The plates of Fig. 2 may be substituted for 25 and all statements made above relative to plates, caps, and downspouts in connection with the boiler apply equally to vessel 0. Instead of bubbler plates, VCSSBIS'B and C may each be provided with spray nozzles located near their highest interior points, connected with pipes 27 and 23,

respectively, and arranged to cause intimate contact between water entering and steam .within the vessels. 7

Receiver A is connected at itslo'wer point with the suction side of. pump 29 by pipe 30 having a stop and regulating valve 3!; The discharge side of pump 29 is connected either to vessel B at a point above plate 24 or to the spray nozzles within B, depending on the'construction selected. Pipe 21 is provided with a stop valve 32. q

The lowest point of vessel B is connected with the suction side of pump 33 by a pipe 34. The

C at a point above bubbler plate 25 by pipe 2 having a stop and regulating valve 35.

The lowest point of vessel C is connected with the suction side of pump 35 by pipe 31. The discharge side of pump 35 is connected with space l5 at a'point above bubbler plate 2| by a pipe 29, having a stop valve 38. r

The lowest point of vessel B'is also connected with the suction side of pump 29 by a pipe 39 having a stop and regulating valve 49. The discharge side of pump 36 is also connected with vessel 13 V at a point above bubbler plate 24, or to spray nozzles within-B, by a pipe 41 having a stop and regulating valve 42. Y

Vessel C is connected at a point at or near its top with space l5 by pipe 43 and pipe 44 having a stop valve 45;

Vessel B is connected, at a point at or near its top with vessel C by pipes 43 and 46, the latter having a stop valve 41. Y r

t is immaterial whether pipe provided it connects with steam at boiler pressure. Vessels B and C are provided with vent pipes 48 and 49, having stop valves 50 and 5!. This apparatus is operated in the following. manner. First assuming it to be cold (except as out thru vent 5 9. At the same time valve-45is opened allowing steam at boiler pressure to fill vessel C, (displacing air thru vent 5| which is slightly openedfor that purpose). Vent valves 1 5e and 5| are closed as soon as vessels B and C are filled with water and steam respectively.

Valves 32 and 45'are now closedand valves 35 and A! are opened, allowing the steam pressure in C to equalize on top and bottom of water body in B. The pump 33 now being started, water is [drawn from the bottom of B thru pipe 34 and discharged thru plate 25, first forming a pool of water ,of the two vessels.

on the plate and thereafter overflowing thru 7 Or, if spray nozzles be used'instead of bubbler plates, the water is discharged into C as a spray or multiplicity of small'streams.

In either event, the steam in C is in large measure condensed, thus reducing the equalized pressure Steam flowing out of C thru pipes and 46 to fill the space in B vacated by thewater comes into intimate contact with the water enteringthe top of C, by the action eitherof the bubbler plates connects with space l5 or with druln l9 above its water line,

or of the spray nozzles, and is thereby reduced in V 1 temperature and pressure-1 Under some conditions, in order to facilitate the attainment of equilibrium between the steam and water, it may be advisable to resort to the following procedure. While water 'is being pumped from B to C, as above described, water is simultaneously pumped from C to B thru pipe 3], pump 36, pipe 4|, and valve 42, the water.

secured and the operation may be continued as long as desired, provided that the flow from C to Bis terminated before that from B to C so that C is finally left filled with water. 7 discharge side of pump 33 is connected with vessel After C has been filled with water by either of the alternative methods above described, valves 35 and i! are closed (also 42 if previously opened), valves 45 and 38 are opened, admitting In this j r boiler pressure to both top and bottom of water.

in C and water is pumped from C thru pipe 31, pump 36, pipe 20, and valve 38 into space H: at a point above bubbler plate 2|, on which it first forms a pool and thereafter overflows downspout 22 and descends to join the body of water in boiler'drum l0. Simultaneously, steam from the boiler flows thru pipe 44, valve45, and pipe 43 into vessel C, which, after all water has been pumped therefrom, is filled with steam at boiler pressure.

The first cycle now being completed, following cycles. are conducted in the same manner with the exception of venting the air and with Valves 38 and 45 are then closed..

thefurther exception that under some conditions, in order to facilitate condensation of steam in B by water entering from A, it may be advisable, while pumping from A to B, to simultaneously pump water out thru pipe 39 from the bottom of B, discharging it on top of plate 24 or intothe spray nozzles in B, depending on the This recirculation may construction selected. 7 be accomplished by adjusting the relative openings of valves 3| and 40 to regulate ratio of recirculated to newly introduced water to any desired figure, the same pump 29 serving to pump both streams, which are merged at the junction of pipes 30 and 39. d

At the time of initiation of any cycle subsequent to the first, the system may, for example,

be in the following-condition:

Receiver A contains water at C. Vessel B is filled with steam at 2.1 atm absolute pressure Vessel C is filled with steam at 50'atm, absolute pressure Boiler D with steam and water at 50'atmx,

absolute pressure. 7 I

The apparatus ilustrated is limited to an intermittent flow of feed water into the boiler. By

providing the apparatus (except A and D)' in duplicate and correctly timing the functioning of the duplicates, it is possible to'produce a con-' tinuous flow of feed water to the'boiler. It is also obvious that the same result can be obtained by duplicating only the vessels B and C and by so arranging the piping that one set of pumps can serve either set of vessels alternately.

In place of manually operated valves it is both i feasible and desirable to use.electrically operated valves controlled by suitable timing means the positions of the various valves in the proper sequence and at such intervals as to permit the apparatus to function as above described. Another obvious modification, which is particularly appliable to electrically operated valves, is to make them responsive thru floats and electrical contacts to changes in liquid level; so that the filling or emptying of one vessel initiates the valve settings necessary for the next step. I do not claim these devices, which could be modiover a wide range and which are not part of my invention, but wish it to be understood that by the use of theterm manual as applied to these valves I do not intend to limit myself to valves actually moved by the hand of an operator.

The number of vessels arranged in series and the pressures described herein are illustrative only. The pressure in vessel B after pumping the water therefrom into C, with any given pressure in the boiler, is reduced by lowering the temperature of the water supplied from A and/ or by increasing the number of condensing vessels such as B and C.

ReceiverA may be replaced by any source of water of desired temperature. If recirculation of water in B is not desired, pump 29 may be dispensed with provided the Water in receiver A, or its equivalent just described, is at sufiicient pressure to overcome the residual vapor pressure in B; or if this water be under sufiicient pressure, the pump may be dispensed with and recirculation retained by the addition of a water operated injector at the junction of pipes 3i] and 39.

The minimum number of parts is, obviously, one water source, one condensing vessel, one pump, one boiler, and the required pipes and valves, but any greater number of condensing vessels may be used. In case more than two condensing vessels are used, they should preferably consist of one vessel of the type illustrated at B, while the rest should be of the type illustrated at C.

It can be seen that by providing the proper number of condensing vessels, the residual steam pressure in the initial vessel can be reduced to any desired value and that if this value is properly chosen, none of the pumps is ever required to pump against any head greater than that of a water column of a height equal to that of a condensing vessel, plus the friction loss in piping and in spray nozzles if used.

In the introduction of feed water intobubbler plates or their equivalent, as in space I5, a small portion of the steam delivered by the boiler is utilized in materially raising the temperature of the feed water, thus reducing thermal stresses in the boiler structure. A further advantage is realized in the removal from the steam supply of a portion of the entrained water particles, the presence of which makes the steam undesirably wet. It will be understood, however, that with the loss of these advantages the water delivered by the train A-B-C may be introduced into the boiler at any level preferred.

When used for feeding boilers, a principaladvantage of the apparatus over feed pumps is economy of power, the water being brought to boiler pressure by consumption of heat in elevating the feed water temperature, this being heat that would otherwise be expended in heating the feed water after introduction to the boiler. The only power required for pumping is that used against the extremely low pumping heads described above; which areiinconsequential come pared to boiler pressure, particularly in the case of modern high pressure boilers.

The principles and the apparatus above described may obviously be' used for feeding liquefied gases into pressure vessels'containing vapors of the same'liquid Theonly'modifioation required is that all parts of the apparatus will require to be heavily insulated against inflow of atmospheric heat. The temperature and pres sure of the final container will be immaterial but the temperature of the liquid in vessel C must not exceed the critical.

If diificulty should be experienced in pumping liquids of extremely low temperature, the vessels through which the introduction is effected may be'arranged for gravity flow instead of pumping, as described for the feeding of steam boilers in" the copending application.

-I claim as my invention:

1. In apparatus for feeding water into steam boilers: a plurality of pressure vessels arranged in series; valved pipes connecting the upper portions of said vessels in series and connecting the upper portion of the last vessel of said series with the steam space of said boiler, and pumping means arranged to move water from each said vessel except the last thereof to the upper portion of the next in the series and from said last vessel into said boiler.

2. A device substantially as and for the purpose set forth in claim 1, including means for returning water from one of said pressure vessels to the upper portion of the next preceding vessel of the series. e 3. A device substantially as and for the purpose set forth in claim 1, including means for circulating water from the bottom to the top of one of said vessels.

4. A device substantially as and for the purpose set forth in claim 1, including means in the 7 upper portion of at least one of said vessels for intimately contacting a flow of water with steam initially contained in said vessel, whereby a portion of said steam is condensed.

5. Apparatus for introducing liquid from a source of supply atrelatively low pressure into a closed receiver containing vapor at relatively high pressure which comprises: a closed pressure vessel; means for introducing said liquid into said vessel and for circulating liquid from the lower to the upper portion of said vessel; means for producing intimate contact between liquid entering said vessel and vapor therein, whereby portions of said vapor are condensed; means for' equalizing vapor pressures between said'vessel and said receiver, and means for transferring said liquid from said vessel to said receiver.

6. Apparatus for introducing liquid from a source of supply at relatively low pressure into a closed receiver containing vapor at relatively high pressure which comprises: a plurality of closed pressure vessels arranged in series; means for introducing said liquid into the first vessel of said series and for transferring said liquid' from each said vessel into the next succeeding vessel of said series and from the last of said vessels into said receiver; means for transferring liquid from at least one of said vessels into a preceding vessel of said series; means for producing intimate contact between the liquid entering each said vessel and vapor therein, whereby portions of said vapor are condensed, and means for equalizing vapor pressures between adjacent vessels and between said last vessel and said re- 7. Apparatus for introducing" liquid from a source of supply at relatively low pressure into .a closed receiver containing vapor at relatively high pressure which comprises: a plurality of closed pressure vessels arranged 'in series; means for introducing saidtliquid into the first vessel of said series and for transferring'said liquid from each said vessel intothe next succeeding vessel of said series and from the last of said vessels into said receiver; means for transferring liquid from the lower part to the upper part of at least one vesl sel of said series; means for producing intimate contact between the liquid entering each said vessel and vapor therein, whereby portions of said vapor are'condensed, and means for equalizing vapor pressures between adjacent vessels and between said last vessel and said receiver.

8. The method of introducing liquid into a closed receiver containing vapor at relatively high pressure which comprises: establishing a supply of said liquid in a closed vessel under relatively low pressure; establishing vapor communication between said vessel and said receiver and thereby equalizing therpres sures therein;

and thereby equalizing the pressures therein;

circulating a stream of said liquid within a closed system comprising said vessel and said receiver, and thereby lowering the pressure'within said system "by condensing a material proportion of said vapor. V l

10. A method substantially as and for the purpose set forth in claim 9, in which said circulating liquid is repeatedly and intimately contacted with said vapor and the condensation of said vapor is thereby accelerated.

LEE S. TWOMEY.

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