US2605856A - Deaerating system for water or steam condensate - Google Patents

Description

5, 1952 Q A. KIRKPATRICK ET AL 2,605,856

DEAERATING SYSTEM FOR WATER OR STEAM CONDENSATE Filed July 2, 1947 61. earn 23 766 for BY Harry H. MMeen Patented Aug. 5, 1952 DEAERATING SYSTEM FOR WATER on 'STEAM CONDENSATE Alton Kirkpatrick, Boston, Mass, and Harry H.

McMeen,Harvey, Ill., assignors, by mesne as- 'signments, to the United States of America as v, Energy Commission represented by the United States Atomic f Application July 2, 1947, Serial No, 758,542

Our invention relates to cooling systems and more particularly to the type of cooling system employing deaerating equipment for the removal of gases and/or otherimpurities ingaseous form from the liquid or circulating medium of the system.

In the operation of production equipment used in connection withjthe electromagnetic process of particle separation athigh potentials and under conditions wherev large power consumption is involved, and where a part of the power is converted into heat energy, it becomes necessary to circulate a cooling medium, such as water, through the walls and heated partsof the apparatus to prevent overheating 'of or injury to such-parts. Due to the high operating potentials of, this equipment and to the fact that the lead line for the cooling liquid is ordinarily maintained at or near ground potential, it is customary to employ lap coils oiinsulated material, such as porcelain, to join the lead lines to the high potential elements of the equipment. Under these circumstances it is necessary that the cooling medium also be a good insulator with a minimum ionization and low conductivityto prevent leakage between'the' elements and the lead lines through this, liquid. To accomplish this result, the liquid or medium is deaerated to remove air and such gases as CO?, (carbon dioxide) which react with the medium when water 'is used, to produce carbonic acid, the reaction being:

undesirable gases to reduce corrosion has been known to the prior art. Examples of such systems may be found in the patents to Elliott, 1,457,153; McDermet, 1,742,998; and Gibson, 1,969,888. These structures, however, fall to make provision for a storage reservoir and a deaerating chamber, both under vacuum to obviate the possibility of gases entering or being absorbed by the liquid. Additionally, they fail to tak into account the necessity for creating sufiicient liquid jaolaims. (01. 183-25) low a predetermined level,

pressure within the apparatus to supply the circulating pumps with liquid at a pressure above that of the surrounding atmosphere.

Applicants with a knowledge of these problems of the prior art have for an object of their invention the provision of a liquid cooling system for electric process equipment which will remove objectionable gases from the-liquid to maintain the high electrical resistance thereof.

Applicants haveas another object of their invention the provision of a deaerating system where both the storage reservoir and the deaerating chamber are maintained under vacuum to prevent the cooling liquid from reabsorbing gases from or in the'air. a a

Applicants have as another object of their invention the provision of'a system employing a contact vacuum deaerator located at an elevation abovethe' pumping arrangement for circulating liquid through the system in order to'build up a pressurev therein to 'overcome the action of the vacuum inthe deaerating chamber, thus avoiding the possibilityof leakage of air through nuinerous system connections.

, Applicants have as a further object of their invention the provision of a system with a deaerator'havingthe storage tank and deaerator chamber in a single vessel and in communication with each other tofacilitate evacuation and removal of undesirable gases. I

Applicants have as a further object of their invention th provision of a system with a deaerator having a storage tank which automatically feeds liquid to the system when the height of liquid in the deaerator section falls below a predetermined level. i

Applicants have as a still further object of their invention the provision of a liquid circulating system for deaeration'of liquids with pressure control inthe return line feeding the deaerator to maintain constant circulation of liquid in the process piping, in the event the vacuum falls be- Other objects and advantages of our invention will appear irom the following specification and accompanyingfdrawing and the novel features thereof:will beparticularly pointed out in the annexedclaims, f

In the'drawing, the sole figure is a schematic diagram ,oifjour improved system showing the deaerator in sectio'rn, w

Referringto the drawing in detail, I designates a contact type vacuum deaerator in the form of an upright cylindrical tank divided into an upper deaerating chamber 5 having'an-active liquid under vacuum. Positioned at a level below the deaerator is a circulating pump 2 which is: connected to the lower part of chamber below the usual liquid level thereof, by a line I4. The pump 2 is then connected by line l6, through the process cubicles I! to the coolers. [8. They discharge cooled liquid throughline [9 into the upper end of the deaerator tank I and chamber 5 through the end of pipe I0 into a tray or trough 23 which continually overflows so that liquid therefrom passes down through a honeycomb or lattice work or over a set of overlapping baflles such as 2|. The liquid cascades over the surfaces of the bafiies or slats and gives off oxygen, carbon dioxide and other gases absorbed therein.

Vacuum is created'in connecting chambers 5 and 3 through line 22, which may be connected to conventional vacuum equipment, preferably a steam ejector 23 supplied with steam from line 24 which discharges liquid through line 40 to reservoir 3. The lower extremity of reservoir 3 feeds into line l6 through line 26 containing pressure valve 9 controlled from line 21 which leads to chamber 5 so that when the water level in the chamber falls below a predetermined point 8, the operation of the float valve 4| through a lever or pressure medium opens valve 9 permitting water to flow from storage reservoir 3 through line 26 and valve 9 into line I4 and. into the system.

In'the operation of the system pump 2 operates under pressures at or slightly above atmospheric in line M'due to the static head of liquid in line 14 being in excess of the vacuum in chamber 5 created by the steam vacuum system 23. In order to overcome the effect of the steam vacuum systemon the flow of liquid in line H and to aid the pump 2 in its operation, tank I is preferably placed at some elevation above pump 2 in order to build up a pressure at the inlet of pump 2.

Liquid flowing through line M and pump 2 feeds into the process cubicles I! through line U l6, thence through closed coolers 13 in order to lower its temperature and dissipate the heat absorbed from the process cubicles ll. While the coolers l8 may be of usual design, they are preferably of a type which do not expose the liquid to the atmosphere where it might absorb air or undesirable gases. Any type of heat transfer unit where the heat is transferred to a secondary cooling liquid which passes over tubes through'which the primary cooling liquid passes, is preferable. The secondary liquid may be cooled by a cooling tower, which causes evaporation, or by spraying or otherwise as may seen most practicable.

On leaving the coolers IS, the cooled liquid is returned throughline l9 to the upper end of tank I. Connecting line M with line I9 is line 29 containing pressure valve ll controlled from line 28 which is in turn joined to line Hi. In the event of a decrease in vacuum in the deaerator a higher, pressure will be created in line 28 which is communicated to-valve H causing it to open and permitting recirculation of liquid to pump 2, thus insuring the supply of cooling water to process.

Where the tank I is at a considerable elevation above pump 2, such pump may not develop sufficient pressure to return the liquid to the top of tank Iin case vacuum is lost in the deaerator. The resulting increase in pressure created in line 28 will open valve ll thus reliev ing the pressure on pump 2 and maintaining flow of cooling liquid to process, as described in the foregoing.

To initially supply water to the system and replace water used or lost during operations, a supply main 30 feeds into line I9. Flow of water through. main 30 to line I9 is controlled by pressurevalve 3| through float operated valve 32 for controlling the pressure applied through line 33 to valve 3|. Float valve 32 is connected to storage reservoir 3 through lines 34, 35 and is responsive to water level in that reservoir for controlling the operation of valve 3|. On the other hand, water may be removed from the system through line 36 and three-way valve 31. The line 24 mayxalso be drained into the reservoir 3 through line 42 by opening valve 43.

Having thus described our invention, we claim:

1. A deaerating system of the character described comprising a container, a diaphragm positioned across said container dividing it into an upper and a lower chamber, a bafile arrangement positioned intermediate of said upper chamber for the passage of liquid to remove entrained gases, means for removing liquid from one extremity of said upper chamber for circulation through a system including heat exchange units and for returning the liquid to the other extremity of the chamber, said lower chamber serving as a liquid storage reservoir, means for connecting said reservoir into the circulating system,rmeans responsive to liquid level in said upper chamber for regulating the flow of liquid from the reservoir to the system, and means for placing the upper and the lower chamber under vacuum pressure. 7

2. A deaerating system of the character described comprising a container, a partition for dividing the container into an upper and a lower chamber, a circulating system including heat exchange units connected to the extremities of said upper'chamber, a baffle arrangement positioned in an intermediate. portion of the upper chamber, means for circulating liquid from the lower extremity of the upper chamber through the circulating system to vthe upper extremity of the chamber whereby the returning liquid flows downwardly by gravity over the bafiie arrangement to release entrained gases therefrom, means for connecting said lower chamber to said circulating system for removing liquid therefrom, means responsive to the liquid level in the upper chamber forregulating the flow of liquid from the lower chamber to the circulating system, and means for placing the upper chamber and the lower chamber under a vacuum pressure. p

3, A. deaerating system of the character described comprisinga container, a partition for dividing the container into a deaerating chamber and a liquid storage chamber, means for circulating liquid through a system including a plurality of heat exchange units and through the deaerating chamber, means carried by the partition for communication between the deaerating chamber and the storage chamber, whereby liquid reaching a predetermined level in the deaerating chamber will drain into the storage chamber, and means responsive to the liquid REFERENCES CITED level in the deaerating chamber for connecting The following references are of record in the the storage chamber with the circulating sysfile of this patent; tem for supplying liquid thereto.

4. A deaerating system of the character de- 5 UNITED STATES PATENTS scribed comprising a container, a partition for Number Name Date dividing the container into an upper deaerating 1,611,256 Suczek Dec. 21, 1926 chamber and a lower liquid storage chamber, 1,636,361 Gibson July 19, 192 an overflow pipe extending upwardly from the FOREIGN PATENTS partition into the deaerating chamber whereby 10 liquid reaching a predetermined levelxin the de- Number fi Date aerating chamber will overflow into the storage 1711757 Great 17) 1921 196,064 Great Britam Apr. 12,1923

chamber, means for circulating liquid through a system including a heat exchange unit and through said deaerating chamber to release en-- 15 trained gases therefrom, and means responsive to the liquid level in the deaerating chamber for connecting the storage chamber with the circulating system to supply liquid thereto.

ALTON KIRIQATRICK. 20 HARRY H. MclVlIElEiN.

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