US3488925A - Liquid degasifying system - Google Patents

Description

Jan. 13, 1970 A. GIARBG-Asr A LIQUID DE'GASIFYING SYSTEM Filed Dec. 11, 19e? k R A. o -LEI MT IsmtkQhhal NQ mmmrg-h .H M m .Nw e d Kwltwkb m m Tm .M R A pvf 6 M I1 A .171. V I! L Q n A n1 wm xlw m A, Q M .lr/ MII .wkwk \\\\\\\N\\\\\\\\\.\\\\\`\\ Y Wm ONM? w\ QWwbQWWQ NN WQ@ mm. w l\ Lw: Sn \\\.\\\\\\-\\\\\\\\\\\u d 1J ATTORNEY United States Patent O 3,488,925 LIQUID DEGASIFYING SYSTEM Alva G. Arbogast, Box 1139, Charleston, W. Va. 25324 Filed Dec. 11, 1967, Ser. No. 689,431 Int. Cl. B01d 19/00 U.S. Cl. 55-192 1 Claim ABSTRACT OF THE DISCLOSURE A degasifying system for use in the treatment of liquid to -be used in industrial process work. The system includes a liash chamber at atmospheric pressure containing condenser coils. The liquid is initially fed through these condenser coils, which are maintained at a relatively low temperature by the incoming liquid. From the condenser coils the liquid goes through a heat exchanger, heated by steam at about 250 F. The hot liquid is released into the ash chamber through a back pressure relief valve. The ashing hot liquid vaporizes and contacts the condenser coils, recondensing and flowing to a storage receptacle. In flashing, the the liquid gives up oxygen, air, or other gases previously contained therein.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to systems for degasifying liquids, and more particularly to a system for the degassing treatment of water to be subsequently employed in industrial processes.

Description of the prior art Fluid handling systems have heretofore proposed the expulsion of super-heated fluids into expansion chambers for various purposes.

SUMMARY OF THE INVENTION A main object of the invention is to provide a novel and improved liquid degasifying system which involves relatively simple apparatus, which is reliable in operation, and which eliiciently removes air, dissolved oxygen, aromatic gases, or other foreign materials from liquid intended to be subsequently employed in industrial processes.

A further object of the invention is to provide an improved water-degasifying system which can be installed in a relatively small space, which is economical to operate, and which employs relatively inexpensive components.

A still further object of the invention is to provide an improved water-degasifying system for use in treating water from boilers, or from any other source, to remove undesired gases or other foreign substances therefrom, the system employing a liquidpashing technique which is highly eiective in separating the undesired gases or other materials from the water, the system employing components which are easy to operate and to maintain in proper working order, the system having a relatively high ilow capacity, and the system being particularlyr suitable for continuous or long-term uninterrupted operation without requiring any substantial amount of human supervision.

A still further object of the invention is to provide an improved 'Water degasication system which is easy to install, which is safe to operate, and which provides a dependable continuous supply of purified degassed water for use in industrial processes requiring same.

Further objects and advantages of the invention will 3,488,925 Patented Jan. 13, 1970 ICC become apparent from the following description and claims, and from the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single iigure of the drawing diagrammatically and schematically illustrates a typical water degasifying system constructed n accordance with the present invention, with certain parts thereof being shown in longitudinal and vertical crosssection.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, 11 designates a flash chamber having the generally cylindrical longitudinal wall 12 and the respective front and rear end walls 13 and 14. Au inlet conduit 15, for water to be degassed, extends sealingly through front end wall 13 to the rear end of a longitudinally extending condenser coil 16- mounted substantially axially in the fonward end portion of chamber 11. The condenser coil has the outlet conduit 17 extending sealingly through the lower portion of wall 13, as shown.

Substantially centrally mounted in front end wall 13 is a relatively small-diameter gas release conduit litting 18 connected to a downwardy pitched conduit 19 leading to a waste conduit 20 under atmospheric pressure. Conduit 19 is downwardly pitched from gas release fitting 1S to minimize the return of sour gas back into the liash chamber 12 and to thereby minimize recontamination of the degassed liquid obtained by the system.

Chamber 11 is provided with a bottom discharge conduit 21 in Wall 12 adjacent end wall 13. Conduit 21 is connected through a water seal unit 22 and a conduit 23 to a storage tank 24 for degassed water to be eventually used in an industrial process.

Water seal unit 22 is protected against siphoning by the provision of an anti-Siphon vent conduit 25 connecting theY top of the inverted -water seal U-bend 26 to the vapor space 27 in the upper portion of tank 24.

Designated at 27 is a conventional heat exchanger comprising an elongated chamber 28 having the opposite outwardly convex end walls 29E and 30, with a vertical partition plate 31 mounted therein adjacent end wall 30. A transverse horizontal partition plate 32 is centrally secured between plate 31 and end wall 30, defining upper and lower compartments 33 and 34. A plurality of U- shaped horizontally extending heat exchanger tubes 35 are provided in chamber 28, with their inlet ends secured in the lower portion of plate 31, in communication with compartment 34, and their outlet ends secured in the upper portion of plate 31, in communication with compartment 33. Chamber 28 is provided in its top wall adjacent plate 31 with a steam inlet conduit 36 and in its bottom wall adjacent end wall 29 with an outlet conduit 37.

Conduit 37 is connected through a conventional steam trap 38 and a check valve 39 to the lower region of storage tank 24.

A source of steam is connected by a conduit 40 through a conventional pressure-regulating valve 41 to inlet conduit 36. The steam supplied through conduit 40 may be under any pressure suthcient to provide steam at the required pressure to line 3'6. The pressure-regulating valve 41 is set to provide an outlet pressure of 15 pounds per square inch gauge, which is therefore at a temperature of about 250 F. The input steam pressure in supply line 40 may be, for example, between 50 and 150 pounds per square inch gauge.

A conventional pressure gauge 43 may be provided, connected to line 36.

The outlet conduit 17 of condensing coil 16 is connected to an inlet conduit 44 in the lower p-ortion of end wall 30 communicating with compartment 34, and thus with the inlet ends of tubes 35. An outlet conduit 45 is provided in the upper portion of Wall 30, communicating with compartment 33, and thus with the outlet ends of tubes 35. Conduit 45 is connected to the rear end of Hash chamber 11 through a spring-loaded back pressure relief valve 46. The spring 47 of relief valve 46 is designed to maintain a back pressure in conduit 45 of approximately 15 pounds per square inch gauge and to allow the valve disc element 48 thereof to unseat when this designated pressure is reached or exceeded. This valve action permits the water in tubes 35 to be heated to a temperature much higher than 212 F., thus providing the heat necessary to :ause ashing of the gas-bearing water as it enters Hash chamber 11, as will be presently described.

Valve 46 is connected to the Hash chamber 11 through a relatively short inlet conduit 49 centrally mounted in rear Wall 14. A baHie plate 50 is mounted on the rear and of condensing coil 16, facing inlet conduit 49, but spaced therefrom by the Hash space 51.

In operation, water containing dissolved oxygen and/ or other non-condensable gases enters the degasifying system through conduit 15 and passes through the condensing coil 16. The temperature of the incoming water .is Jelow 100 F. This relatively low temperature keeps the surface temperature of the coil 16 cool enough to con- :lense any steam coming into contact with its surface.

The non-condensable gas released within the Hash :hamber 11 is vented out of the system through the gas release fitting 18 and conduit 19 to the waste conduit 20 Jnder atmospheric pressure. As above mentioned, conduit 19 is pitched downwardly from gas release titting 18 to ninimize the possibility of sour gas flowing back into chamber 11. This avoids recontamination of the degassed liquid in the system.

Gas-bearing water Hows from coil 16 through conduit l7 into compartment 34 and thence through the steamheated tubes 35 of heat exchanger 27. The steam inside the chamber 28 surrounding the tubes 35 is maintained at 15 pounds per square inch gauge, with a correspondlng saturated temperature of 250 F.

The condensate in the heat exchanger chamber 28, resulting from contact of the steam with the tubes 35, :irains off through conduit 37, stern trap 38 and check valve 39 into the storage tank 24.

Gas-bearing water at 250 F. leaves tubes 35 through :ompartment 33 and conduit 45'and enters the back Jressure relief valve 46 at 250 F.

The pressure of the gas-bearing Water Howing into the Jalve 46 is maintained close to 15 pounds per square inch gauge by the biasing action of the spring 47 on the valve.

iisc element 48. This valve action permits heating the Yvater to a temperature much higher than 212 F., thus nroviding the heat necessary to cause Hashing of the gas- Jearing water responsive to the unseating of valve disc :lement 48, which occurs as a result of the pressure buildip beneath the disc element. The water Hashes into steam 1s it enters the Hash chamber 11 through the short coniuit 49, the chamber 11 being at a pressure only slightly nore than atmospheric, wherein the corresponding water )oiling point is only slightly higher than 212 F.

Chamber 11 operates at a pressure slightly higher than xtmospheric because of the water seal 22 and the restric- .ion caused by the relatively small-diameter outlet coniuit 18. This pressure is of the order of 2 to 3 inches )f water above atmospheric pressure. As above menioned, the water seal 22 cannot siphon because it is proected from siphoning by conduit 25 which is connected o the vapor space of the storage tank 24.

When Hashing occurs in space 51, the undesired oxygen water, separate out, the separation action being aided by the impact of the Hashed liquid against the baie plate 50, although it is mainly caused by the sudden expansion which occurs when the superheated liquid Hashes into steam.

As the Hashing water enters the chamber 11, heavy liquid particles fall to the bottom of the chamber and the Hash steam and liberated gases break free in the space 51 inside the chamber. This steam and gas mixture strikes the baHie plate 50, which forces it to flow into the space surrounding coil 16.

The degasied water vapor condenses as a result of contact with the condensing coil 16, and all the resultant degasiiied water discharges through conduit 21 and water seal 22 to the conduit 23 and thence to the storage tank 24, completing the cycle.v

While a specific embodiment of an improved water degasifying system has been disclosed in the foregoing description, it will be understood that various modilications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

I claim:

1. In a liquid degassing system: a Hash chamber having a forward end wall and a rear end wall and a horizontal axis; means substantially venting said Hash chamber to atmosphere comprising a relatively small diameter gas vent conduit mounted in the forward end wall of the flash chamber, said gas vent conduit being downwardly pitched from its connection with said forward end wall to minimize the return of gas back into the Hash chamber; a longitudinally extending condenser coil mounted substantially axially in the forward end portion of the chamber; a baffle plate transversely mounted on the rear end of said condenser coil; a source of water to be degassed; conduit means connecting said source to one end of the condenser coil; a heat exchanger having heat exchanger tubes, a heating space surrounding said tubes, and respective inlet and outlet spaces in communication with the ends of the tubes; conduit means connecting the outer end of the condenser coil to said inlet space; a source of superheated steam at a temperature of the order of 250 F.; conduit means connecting said last-named source to said heating space; said Hash chamber rear wall being provided with a substantially centrally-located, relatively short inlet conduit; conduit means connecting the outlet space of the heat exchanger to said short inlet conduit; a spring-loaded back pressure relief valve in said lastnamed conduit means located adjacent said inlet conduit and having a loading spring designed to maintain a back pressure in said last-named conduit means corresponding to a water temperature substantially higher than 212 F., whereby to provide the heat necessary to cause flashing of gas-bearing water as it enters the Hash chamber, storage means for degassed water; and conduit means located to the forward wall connecting the bottom of the Hash charnber to said storage means.

References Cited UNITED STATES PATENTS 2,515,648 7/1950 Hunt et al. 55-166 X 2,556,107 6/1951 Roswell 165-40 2,908,618 10/1959 Bethon 202-180 X REUBEN FRIEDMAN, Primary Examiner R. W. BURKS, Assistant Examiner

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