US1607070A - Water deaeration - Google Patents

Description

News 16 G. H. GIBSON WATER DEAERATION Filed March 24, 1922 Patented Nov. 16, 11926.

UNIT :1;

GEORGE E. GIBSON, OE HONTCLAIR, NEW JERSEY,

:E'NT orric ABSIGNOR T0 COCHRANE COE- vmm.

war'ra DEAERATIQN.

Application filed. ms 24., 1922. Serial No. 646,262.

The general object of my present invention is to provide an improved method of, and apparatus for heating and deaeratmg feed water.. More specifically, one main ob- B jectof my invention is to provide an improved method of, and apparatus for heatmg and deaeratin boiler feed waterv in a power plant in w ich there are normally available for feed water heating and deaerating purposes, a supply of exhaust steam at a pressure appreciably below that of the atmosphere, --and a second source of steam at, or above atmospheric pressure.

In such case I utilize steam at the low' is pressure available to heat the feed water up to the temperature of that steam in a jet condenser, preferabl of the barometric columndischarge t pe, from which the water is passed into a eating and deaeratlng ap;

so paratus of the general character of an open feed water heater in which steam at the higher pressure available is employed "to heat the water. to a tem slightly above 212. In thls ap aratus-the water is advantageously agitate as wellas heated and the air. liberated from the-water is permitted to escape to the atmosphere through a suitable vent.

Another important specific object of my invention is to provide improved means for utilizing the water or a portion of it passedinto each heating chamber for treatment therein, for cooling the air and vapor mixture withdrawn from the chamber to thereby reduce the moistpre content of the mixture. This reduces the heat carried out of the apparatus by the vapor, and reduces the volume of the escaping air and vapor mixture which is of importance in some cases as it permits of; the use of exhausting apparatus of smaller capacity than would otherwise be required; By proceeding in'the manner described, I am enabled to heat and deaerate water with comparatively simple and reliable apparatus, which provides, moreover, a desirable storage space for the water treated, and with an effective and economical utilization of the steam, and particularly of the steam available at low pressure, which is employed to heat the water'and eliminate the air. I

The various features of novelty which characterize my invention are pointed out rature. of, or Th with particularity in the claims annexed to and'forming a part of this specification. For a better understanding of theinvention, however, and the advantages possessed by .it, reference should be had to the accomin which I have illustrated and described preferred embodiments of my invention.

Of the drawings: i t Fig. 1 is a diagrammatic sectional elevalon; a f

Fig. 2 is an enlarged section of a portion of the apparatus shown in Fig. 1, the section being taken on the line 22 of Fig. 1;

Fig. the a view taken similarl illustrating a modifiedform of t tus shown in Fig. 2; and

F Fig. 4 is a section on the line 4-'4 of In the construction diagrammatically illustrated in the drawings, A'represents the main supply pipe for water to be treated. e ipe A discharges into the upper end of a et condenser B of the barometric col-' umn type which preferably,,as shown, is of the form in which an overflow trough C, and bafilesor trays B are arranged in the e apparasteamspace'of the condenser to facilitate the ra id and effective heating of the water at wi ely varyin rates of delivery by the steam which is admitted to the steam space of the condenser through an inlet B. Ad-

vantageously the trays or bafiies B are en .closed by a bafile B or are otherwise so disposed that the only vapor path between the steam inlet B? and the air and vapor outlet piping O leading from the condenser B is through the space between the trays or baflies B The overflow trough C provided is advantageously formed with special provisions adapting panying drawings and descriptive matter to Fig. 2 c

it for effective utilization in cool-' ing and thereby reducing the vapor .con-

tent in the air and vapor mixture, which passes out of the condenser C through the outlet pi ing 0'. As shown the overflow trough C comprises a trough chamber C proper with hollow side walls. In the chamber C formed ip eachhollow side wall of the-trough C are located a series of transverse horizontal overfiow troughs C which receive water from the trough C through small orifices (I which are located above the level of the bottom of the pipe A so that the othercnd of the trough.

the latter-f is water sealed. The water overflowing irom the small troughs 0* runs C is separately connected to the air and ceeds that of the atmosphere but with the air "passes from the vapor outlet piping O, the connection being at the opposite end of the chamber from thBCCOI'IGSPOIIdlIIg 'air inlet and water outlet P.

The barometric column discharge pipe'B of the condenser B opens into the upper end of a second'water device D. The latter is of the general character of an open feed water heater, and comprises an overflow trough into which the pipe B discharges, and adjacent trays or haflles' D so enclosed by partitions D or otherwise so disposed with reference to the shell of the device D, that the only vapor path from the space beneath the trays D to the vent or air and'vapor outlet, piping D opening from the top of the chamber 3 in which the ba-tfies D are located, is through the space between the trays. The trough: CA maybe and is shown as identical in form with the trough C. 7 Advantageously the through which the airand vapor admixed chamber d to the atmosphere includes a throttle .valve F which in ordinary operationcis never entirely closed, butth'e effective port area of which may be adjusted to meet varying operating conditions. For safety purposes the vent piping D may also be provided with a so-called back pressure valve FA such as is commonly employed withopenfeed water heaters, and which is so adjusted as to open whenever the pressure in the heater D ex which will .check'the influx of airinto the heater at fold adapted a to moments when for one reason or another the pressure. in the heater may become less than that of the atmosphere.

' As shown the partitionsD are arranged to pass the water, leavingthe chamber 11 on to the inclined upper portion of a bafile l) which, in the construction shown cooperates with the adjacent side wall of the heater I) to form a conduit for carrying the water to the bottom of-the water. storage space in i the heater, adjacent a 'reboiler G. The latter" is advantageously in the form of a manidlschargea plurality of jets of steam into the mass of water in the lower stantia 1y below that of the water level X normally maintained in the heater. The

heating and deaerating vent piping D V ortion of the heater, ata level sul)-.

ticular construction illustrated,the pipe L is connected to the discharge column B adjacent-the lower end of the latter. Air and vapor withdrawn from the steam space of the condenser B through the piping O by the live steam ejector 0 passes through the discharge pipe 0 of the latter into the heater D, advantageously entering the latter, as shown, immediately below thlowermost baffle D Advantageously a partition .15 extends upward from bottom of the heater D to a height somewhat below that of the water level X thus dividing the lower portion of the water storage space in'the heater D into two compartments in one of which the reboiler G is located while the water outlet D? opens from the other of these compartments. Advantageously one or more pairs of Vertical baflles E and E are interposed between the partitionE and the water out.-

let D, the baffles E being spaced awav from the bottom wall of the heater and extending to a level above the water level X while the baffles E extend from the bottom wall of the heater up to a level somewhat below the water. level X. The bajflles or partitions 'E' and E are provided with oppositely' projecting interspersed transverse baflies E This baflie and partition arrangement is provided to cause the water passing away from the reboiler over the top of the partition'E to flow in a zig-zag path to the water outlet 1), with a resultant agitation of'the water which facilitates'the separation from. the water-of the air contained therein.

As-shown in the drawing, there are twosources of steam supply for the reboiler G. One of theselis the upper steam supply connection'I-l which opens to the topof a valve geously provided with an operating fioat- H the purpose ot-which is'to prevent back flow .of water through the steam connection H in case the pressure in'the supply connection H falls below that in the heater 1).

-The second steam supply connection I to the reboiler G is intended to serve as an auxiliary or supplemental-supply" connec-- tion and contains aregulating valve J. The valve J in the preferred construction shown close accordingly as the pressure in th steam space of the heater D falls below, or

is automatically actuated soas to open and iao I rises above the pressure which it is desired to maintain therein. For this purpose the stem J of the valve J,'in the construction diagrammatically illustrated, is connected tageously be exhaust steam from a so-called house turbine or auxiliary, the exhaust pressure of which is appreclably below that of the atmosphere so that thesteam passing to the inlet B may be ata temperature'of 160. or so. Where theplant does not comprise a house turbine or auxiliary which may advantageously supply the steam needed at the desired low temperature, thesteam supplied-to the inlet B may advantageously be taken" from a low pressure intermediate stage of the main turbine.

The steam. supplied to the reboiler G through the inlet connection 1-1 -will pref-1f erbly be exhaust steam from a house tur bine -or auxiliary, the exhaust pressure of which is a couple of pounds or so above that of the atmosphere if the plant comprises such a house turbine or auxiliary. If

- the plant does not comprise such an available source of steam supply to the connection H, steam may be supplied to the latter from, an intermediate stage of the main ,turbine unit adapted to furnish steam at the desired pressure. The steam supplied by the con-' nection I to supplement, as required, that furnished through the connection H, may be live steam, or may be taken from the stage of the main turbine unit in which thepressure is higher than that of the steam sup--' 'plied through the connection H.

The apparatus disclosed is comparatively simpleand forms an effective instrumentality for heating the water in stages and efi'ectivel freeing it from air or other gases held in t e water.

provision of this. storage space and of the aflles thereinforcausing the stored water to be agitated as it moves-to the water outlet facilitates the liberation of the air mechanirally held in the water, and the liberated air may leave the water at'any point v in the relatively large upper surface.

of the water in the ater.

By heating boiler feed water in a plurality of stages, when steam is available for partially heating the water at the pressure or pressures below that corresponding to the It also provides a desirable storage space for heated water and thev pressure of steam at, the final temperature to which the water to be heated certain known advantagesare obtained. In accordance with the present invention I obtain the. known advantages of heating the water in stages in cases where steam for partially heating the water is available at a pressure corresponding to a temperature lower than that oi the final temperature ofthe water in relatively simple, reliable and inexpensive apparatus which not only heats the water, but forms effective means for the liberation of air contained, in v, the water. It will be apparent, of course, to those skilled in the art that the invention may be utilized with a somewhat I greater I efiiciency'by heating the water in. more than sider the simplification of the apparatus and operating conditions resulting from two stage heatingof the water as compared with heating the water in a] greater number of stages, to be preferable ,to the somewhat greater heatefiiciency obtainable by heating the wateriin a greater number'- of stages.

The special form of overflowwater distributing trough C shown in Figs. 1 and 2 form an efiective instrumentalitv for utilizing the water entering each heating chamber to cool theair and vapor mixture leaving the latter and thus reduce the vapor content in' the mixture. Air being a poor conductor of heat, the'eflective cooling of the air and vapor mixture requires an extended area of contact surface between the mixture be-' ing cooled and the cooling medium whether the. latter be water sprayed ithrough the mixture, metal cooling walls, or is otherwise constituted. With the special con- Struction ofthe trough C disclosed, the air and vapor mixture passing through each" chamber C traverses the broken streams of water falling from the sides of the difierent small troughs C, and flows along extended contact surfaces formed by the liquid in the bottom of "the chamber C and the side and top walls of the latter. While adequate cooling. of the air and vapor mixture requires anbxtended area of contact surface between the mixture and the coolin liquid or surfaces,"theamountof heat to be abstracted is comparatively small, and hence it is unnecessary to pass through the troughs C allot the water supplied to the trough (3 when the apparatus isbperating two stages, but for practical reasons I con-' at full capacity, and-in such a trou h' eon struction as illustrated in Figs. 1 and 2, I advantageously so restrict the various ports C that only a comparatively small fraction,

say 25% or so, of the water supplied tothc trough ,(3 when the apparatus is operating at full capacity, will pass out of the trough chamber C through the ports C The remainderof the water supplied to the trough C will overflow from thetrough chamber-C i to the baflies B or B when the apparatus is operating at full capacity, than would be obtainedif all the water were then passed through the chambers C and discharged on to the trays through the outlets C". The fact that in the air cooler described, the passagesfor the air and steam mixture are comparatively smallfin cross section and the velocity-of flow of the air and va or mixture therethrough is comparative y high,

adds to the etlioiency of the apparatus.

It will be apparent to those skilled in the art that the above mentioned advantages.

obtained with the special trough construction shown in Figs. 1 and 2 ma be obtained with various other constructions, and 'in Figs. 3' and 4 I haveillustrated one modification which maybe employed for this purpose. In Figs. 3 and lathe trough CA, replacing the trough C first described, com- .prises a trough chamber C with distributed small discharge orifices, C in its bottom wall. The aggregate capacity of the discharge ports C may, like that of the ports C of the construction first described, be sufiicient to discharge only or so of the water entering thetrough chamber C through the pipe B when the apparatus is operating at full capacity. The remaining portion of the water then'supplied to the chamber-(1 overflows the side walls of the trough in the usual manner. The water passing out of the chamber C 9 through the ports C in the bottom Wall of the latter enters one or the other of two subjacent chambers C which underlie. the chamber C. and are each provided at one end witha water outlet and air and vapor mixture inlet C? corresponding in location and purpose to the ports C of the construction first described. The openings C of the two chambers 4 C are advantageously located at opposite ends of the trough CA,

I and the connectionbetween the vent piping I) and each chamber C is located at the opposite end of the chamber from the corresponding water. outlet C tageously bafiles C are provided on the bottom wall of the trough chamber G to provide a waterseal about the lower end of the pipe B With the described construction the air and vapor mixture passing through each chamber C traverses broken streams of finely divided water entering the chamber through the ports C distributed along the length of the chamber.

1. The method of efiectively utilizing available steam from two sources one of Advair 7 While in accordance with the provisions of the statutes I have illustrated and described the best embodiment of my invention now known to me, it will be apparent to those skilled in the art that various changes may be inade in the form of the apparatus disclosed without departing from the spirit which is at a pressure below, andthe other at a pressure above, that of the atmosphere in heating and deaerating water, which consists in first heating thewater by contact with steam at the lower pressure in a chamber in which a pressure less than that of the atmosphere ismaintained, and then heating the water by contact with steam at the higher pressure in a second chamber provided with an air vent to the atmosphere, and withdrawing air from the first mentioned chamber and passing it into the second chamber. 7

2. The method of heating and deaerating water which consists in passing the water treated first through one, and thenthrough a second closed heating chamber so as to are into said second chamber from said onechamber as required to maintain a pressure in-- the vapor space of said one chamber appreciably below that of the atmos here, supplying steam to said second chain 1' to maintain a temperature therein above 2129, and venting air from the latter to the atmosphere, s I

3; Apparatus for heating and deaerating water,- comprising in combination two water heaters each comprising a closed chamber with steam and water inlets and a water outlet, means for passing the water treated successively through the two heaters and so as to maintain a vapor space in each,

means for supplying steam at a pressure less than that of the atmosphere to the steam inlet of the heater through which the water passes first, means for-supplying steam to the steam'inlt of the other heater to; maintain a pressure in the vapor space of the latter above that of the atmosphere, said heater having an air vent, and means for withdrawing air from the heater through which the water goes first; and passing it into'the other heater. y y

4. Apparatus for heating and deaerating water comprising in combination a water heater of the jet condenser type with a baremetric column water outlet pipe, a secondary water heater of the open feed water heater water heater of the jet condensertype wit 1 a barometric column water outlet pipe, a second water heater of the open feed water heater type provided with an air vent to the atmosphere, and located below the first mentioned heater and into which said pipe opens,

means for passing the water to be treated successively through the primary and secondary heaters, means for supplying steam at a low pressure to the primary heater, means for supplying steam at a higher pressure to the second heater, and means for withdrawing air from the primary, heater and passing it into the second heater. 7

6. In water heating and deaerating apparatus, the combinationwith a heating chamber and provisions normally maintaining a body of water therein and a vapor space above said water, and provided with a normally submerged steam inlet, of two steam supply connections to said inlet, one from a .source of steam the pressure of which varies between a pressure below and one above that which is the desired pressure in the heating chamber, and one from a source of steam at a pressure above said desired pressure, a check valve preventing back flow of water through the variable steam pressure supply connection, a valve in the other steam supply connectoin and operating means therefor automatically responsive to the ressure in said heating chamber for opening and closing said valve accordingly as the pressure in said chamber falls below and rises above the desired pressure.

7 In a water heater comprising. a heating chamber, means for supplying water to the upper portion of said chamber and with drawing it from the lower portion of said chamber as required to maintain the chamber partially filled with water, and 711183118 for supplying steam to said chamber to heat the water passing through the latter, the improved means for introducing water into the chamber and withdrawing air therefrom which comprises an overflow trough located in the heating chamber above the water level therein and into which the water entering the chamber is first passed, and an air cooling chamber located in the heating chamber and comprising a port for the entrance of air and vapor' and the discharge of water, and an outlet port for air and vapor, and means forpassing water into'said cooling chamber from said trough restricted to pass only a portion of the Water received by the trough when the latter is operating at full capacity. 4

8. Water and deaerating apparatus com prismg in combination a water heating and chamber having an outlet opening from said outlet compartment, and'bafiies for causing the water to 'flow in alternate up and down passes between said reboiling compartment and said outlet.

9. Apparatus for heating and-deaerating water comprising in combination a primar water heater of the jet condenser type with a barometric column water outlet pipe, a second water heater of the open feed water heater type provided with an air vent. and located below the first mentioned heater and into which said pipe opens, means for supplying steam at a pressure below that ofthe atmosphere to the primary heater, means for supplying steam to the secondary heater at a pressure above that of the atmosphere including provisions automatically responsive to the pressure in the secondary heater for regulating the amount of and means for drawing air from the primary heater,

10. Apparatus'for heating and deaerating .into which said pipe opens, means for su plying steam at apressure below that of t e atmosphere to the primary heater, means,

for supplying steam to the secondary heater at a pressure above that of the atmosphere, and a steam ejector drawing air and vapor a'partition dividing the.

steam so supplied from the primary heaterand discharging it into the secondary heater.

11. In a steam power plant, means for heating and deaerating boiler feed water comprising in combination a primary water heater of the jet condenser type with a barometric column water outlet pipefa second water heater of the open fee water heater type provided with an air vent and located Y below the first mentioned heater and into the upper portion of which said, pi e opens, means or passing return water 0 condensation into the primary heater, means for supplying steam at a pressure'below that of the atmosphere to the primary heater, means for supplying steam to the secondary heater at a ressure above that of the atmosphere, a ma 7 e-up water supply connection opening tosaid pipe at a level adjacent that at the top of the second heater, means responsive to the accumulation of water in the second heater for regulating the supply of make-up water through said connection, and means for" withdrawing air from the primary heater. p

12. InIwater heating and deaerating apparatus comprising a heating chamber, normally partially filled with water, with a vapor space above the water, and means for supplying steam to said chamber to heat the water therein, the improved means for in-. troducing Water into the chamber and withdrawing air therefrom which comprises an overflow receptacle located in said vapor space provided with an overflow surface, a water supply pipe dipping into said receptacle, an air cooling chamber located in said vapor space, and formed with ports providing an inlet for air and vapor, an outlet for water, an out-- let for vapor and one or more passages opening from said receptacle at a level below that of its overflow surface for passing water into said cooling chamber from said receptacle, said passage or passages being restricted to pass a fraction only of the water supplied to the receptacle when the apparatus isoperating at full capacity.

13. In water heating and deaerating apparatus comprising a heating chamber nor-.

mally partially filled with water, with a vapor space above the water, and means for supplying steam to said chamber to heat the water therein, the improved means for introducing water into the chamber and withdrawing air therefrom which comprises an overflow trough having horizontally elongated hollow side walls over which the water may overflow, each hollow side wall com.- prising an air cooling chamber provided with a bottom port admitting air and vapor and discharging water, and with an outlet port for air and vapor, and with water inlet ports opening from said trough below its overflow edges and restricted to pass less than the total amount of water entering the trough when the apparatus is operating at full capacity, and a water sealed pipe dipping into said trough for supplying water to the latter.

14. The method of utilizing steam bled from a steam turbine at difierent pressures in heating and deaerating water which consists in first heating the water by contact with steam bled from the turbine at a lower ressure in one chamber, then further heat-- mg the water by contact with steam bled from the turbine at a higher pressure in a extended horizontal Leonora second chamber and subjecting the water to a vigorous scrubbing action in one of said chambers, passing air liberated from the water in one of said chambers into theother chamber, and withdrawing air from the'last mentioned chamber.

15. The method of heating and deaerating water which consists in passing the water successively through a plurality of heating chambers each of which contains asteam space through which the water is passed in divided form, supplying steam to the two chambers so as to maintain a'substantially higher pressure 'in the steam space of the chamber through which the water passes last than in the steam space of the chamber through which the water passes first and so as to subject the water to intimate contact with steam in each of said chambers and to a vigorous scrubbing action in one of said chambers, paming air liberated from the water in one of said chambers to the other chamber and withdrawing air from the last mentioned chamber.

16. Apparatus for heating and deaerating water comprising two heating chambels and connections for passing the water to be heated successively through the two chambers, a connection between said chambers through which air and vapor may pass from one chamber into the other, means for withdrawing air from the last mentioned chamber, and means for bringing steam into contact with the water in each chamber in such manner as to maintain an appreciablyhigher steam temperature in one chamber than in the other, said last mentioned means including means for subjecting the water to a vigorous scrubbing action by the steam in .one of said chambers.

17. Apparatus for heating and deaerating water comprising two heating chambers and connections for passing the water to be heated successively through two chambers, a connection between said chambers through which air and vapor may pass from one chamber into the other, means for withdrawing air from the lastmentioned chamber, means'for maintaining difi'erent steam pressures in the two chambers including a separate turbine bleeding connection to each chamber, and means in one of said chambers for subjecting the water to a vigorous scrubbing action by the steam admitted to said chamber.

Signed at Philadelphia in the county of Philadelphia and State of'Pennsylvaniai this twenty first day of March A. D. 1922.

econ-cs H. GIBSON.

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