US2384511A - Desuperheater - Google Patents

Description

Sept' 11, A1945- A. ,.1. WEGMANN A 2,384,511

4 DESUPERHEATER Flehd April 9, 1942 Patented Sept. 11, 1945 DESUPERHEATER Adolph J. Wegmann, Flushing, N. Y., assigner to Dri-Steam Products, Inc., a corporation of Delaware Application April 9, 1942, Serial No. 438,295

Claims. (Cl. 183'-22) This invention relates to gas and liquid contact apparatus and more particularly to apparatus for desuperheating steam, that is, treating superheated steam to convert the superheat thereof into saturated steam for heating and other purposes.

I am aware that it has heretofore been proposed to convert superheated steam into saturated steam by injecting a spray of water into a passing stream of superheated steam. I am also aware that desuperheaters have been designed on the principle of causing the superheated steam to pass through a cartridge of woven Wire which is kept wet by causing Water to trickle down over the wire mesh forming films in the mesh over and through which the superheated steam is caused to travel and in passing to give up its superheat. Such prior constructions do not insure that the saturated steam delivered from the desuperheater Will be dry and free from entrained particles of moisture and consequently there will be a tendency for moisture to separate out and accumulate in the saturated steam line.

One of the objects of the invention is to provide an improved desuperheater construction capable, quickly and in a small space, of converting superheated steam into saturated steam and to separate therefrom excess particles of liquid and/or foreign substances.

Another object of the invention is to provide an improved desuperheater construction so arranged as to insure more intimate contact between the superheated steam and a jet or mist of water injected into the flow of steam while at the same time bringing about a more efficient transfer of the superheat of the steam into saturated steam.

Still another object of the invention is to provide an improved desuperheater construction which will insure the conversion of a high proportion of the superheat of superheated steam into saturated steam and at the same time insure that the saturated steam passes from the desuperheater in a dry state.

I accomplish the above and additional objects of my invention by providing in a chamber having an inlet and outlet for passage of steam therethrough a spray nozzle to issue a spray of Water across and in a direction counter to the flow of the superheated steam for intimate contact therewith. The chamber is further arranged to cause the steam to undergo a sharp reversal in the direction of flow after the water spray treatment, and finally to pass through a wire mesh to further intermingle and promote heat transfer between the steam and particles of water entrained therewith.

More particularly, the steam is caused to ow in a .downward direction in the desuperheating chamber either before or after contact with the water spray. In the embodiment hereinafter described in detail'the Water spray is directed upwardly from adjacent the bottom of the chamber into the downwardly flowing steam. After contact with the water, the flow of steam is sharply reversed from a downward flow to an upward now, the reversal causing the larger particles of water and any foreign substance contained in the steam or in the water to be thrown out and collected in the lower portion of the chamber from which it is drained. The upward flow of steam and such remaining small particles of water as are entrained therein are passed through a body of screen mesh which, being heated by the steam, operates as a heat exchanger and converts into steam the particles of water carried thereto.

` The screen mesh provides numerous small'passages, the total cross-sectional area of which is greater than the cross-sectional area of the steam pipe so that the velocity of the steam through the screen mesh is less than in the steam pipe. The capillary action of the screen upon the water deposited on the surfaces and in the meshes tends to prevent the water from being carried into the steam pipe before it is evaporated. Should the screen or the inlet portions thereof become undulywet, the excess Water will drain therefrom to the bottom of the chamber without chance of being drawn into the outlet connection.

The intimate contact of the steam with a water spray and the downward flow thereof into the lower portion of the chamber and the sharp reversal adjacent the drain basin insuresadequate drainage of excess water so that the steam pipe will not become flooded by improper manipulation of the watercontrol. The control of the supply of Water to the nozzle may be either manual or automatic, that is, the supply may be controlled automatically in accordance with the temperature of the steam exiting from the desuperheater chamber,

For a better understanding of the invention, reference may be had to the following detailed description to be read in connection with the accompanying drawing, in which: v

Fig. 1 is a vertical sectionalr view of the'desuperheater apparatus of this invention;

Fig. 2 is a cross-sectional view taken substantially along line 2-2 of Fig. 1, and

Fig. 3 is a vertical sectional View taken substantially along line 3-3 of Fig. 2.

Referring to the drawing, the apparatus for desuperheating steam comprises a housing I and a cover I2 dening a desuperheater chamber I4. The housing I0 has an inlet connection I6 and an outlet connection I8 for connection in a steam line or to any other source of superheated steam. The inlet connection includes a tubular portion II which extends inwardly of the chamber I4 to the vertical axis thereof and then downwardly to provide a vertical tubular portion I9. The tubular portion I9 terminates in the lower portion of the chamber I4 a short distance from the bottom thereof. Disposed in the bottom wall of the chamber is a raised boss 20 adapted to support a nozzle 22 in substantial alignment with the open end of the vertical tubular portion I9. Water is atomized and sprayed upwardly from the nozzle into the portion I9 in the form of an inverted cone 23 counter to the ow of superheated steam. The raised boss 20 forms, with the walls of the chamber I4, an annular drain basin 24 having a drain connection 25.

The housing I0 is provided with an inwardly extending horizontal flange 26 disposed below the outlet connection I8. 'I'he flange 26 is connected to thetubular portion I9 and extends therearound, as shown in Fig. 2, for about /8 of its circumference. The wall of the vertical tubular portion I9 to which the flange 26 is connected is extended upwardly above the horizontal portion II to form a partition 2l. Disposed upon the flange 26 between the partition 21 and the side walls of thev housing IU and on opposite sides of the axis of the inlet and outlet connections I6 and I8 are two bodies of wire mesh 30 and 32. Each body of wire mesh extends from the flange 26 to the .cover I2. A pair of upright flanges or bosses 34 and 36 on the horizontal flange 26 provides abutments to maintain the wire mesh in proper position. comprise any suitable filtering screen and, as shown, may comprise a multiple of layers of screen arranged to provide a plurality of narrow arcuate passages through which the steam may ow.

As illustrated in Figs. 2 and 3, the radial crosssectional area of thetwo bodies of mesh is considerably greater than the cross-sectional areas of the inlet and outlet connections I6 and I 8.

Likewise, the total cross-sectional area of the numerous passages provided by the screen mesh is greater than the cross-sectional areas of the connections so that the flow of steam through the screen is at a lower velocity than the ow thereof through the connections.

In the operation of the desuperheater, water is fed to the spray nozzle 22 and sprayed as indicated at23 (Fig. 1) into and counter to the superheated steam flowing downwardly through the tubular inlet portion I 9. The nozzle 22 atomizes the water and sincev it directs Athe spray counter to the flow of superheated steam a thore ough mixture is eiected. As the steam and water mixture proceeds downwardly into the lower portion of the chamber I4 it is caused to reverse sharply to an upward direction. This reversal in flow causes the larger particles of water unevaporated by the initial contact with the steam, together with any foreign substances, such as dirt, scale, etc., to separate out for collection in The mesh may v the basin 24. The steam and finer particles of water entrained therein flow upwardly through the chamber I4 and divide into two streams for flow through the two bodies of screen mesh 30 and 32. The screen mesh intercepts and collects from the steam the unevaporated particles of water, and since the screen is elevated in temperature by the steam, evaporation of the particles results before they can work their way through the mesh, The screen, due to capillary action, retards movement of the water through the mesh until it is evaporated. Should' excess water be carried to the screen by improper operation of the supply controls, drainage of the excess water from the screen is insured by the extension of the lower end thereof well below the outlet I8.

While I have shown but one embodiment of the invention, I recognize that many variations in structure and arrangement are possible without departing from the invention. It will be understoodptherefore, that the embodiment shown and described is to be regarded as illustrative only and not as limiting the scope of the appended claims.

I claim:

1. Apparatus for treating superheated steam comprising means defining a chamber having inlet and outlet connections, said inlet connection having'a terminal portion formed within and extending downwardly into the'lower portion of said chamber, a nozzle disposed to atomize and spray water upwardly into the open end portion of said inlet connection counter to the flow of superheated steam downwardly therethrough, a horizontal partition extending inwardly of said chamber from its sidewall at the outlet side thereof and beneath said outlet connection to said terminal portion of said inlet connection, and terminating short of the opposite side wall of said chamber, said partition, the side walls of said chamber and said terminal portion of said inlet connection further defining therebetween an enlarged space beneath and immediately adjacent the openend of said terminal portion in communication with a second enlarged space above saldi-partition, whereby steam passing downwardly through said terminal portion in countercurrent relation to a water spray injected upwardly into said terminal portion is caused to take a sharp reversal in direction of flow upwardly to said second enlarged space in flowing toward said outletconnection, and a body of wire mesh supported'on said partition and defining a plurality of narrow passageways through which steam passing'upwardly from the open end of said inlet connection to the space above said partition must travel in iiowing to said outlet connection.

2. Apparatus for treating superheated steam comprising a vertically disposed cylindrical chamber having steam inlet and outlet connections in opposed relation in the side walls thereof, said inlet connection having a downwardly extending terminal portion within and substantially coaxial with the vertical axis of said chamber, the lower end' of said terminal portion opening into said chamber, a nozzle disposed to atomize and spray water upwardly into the terminal portion of said inlet connection, a horizontal partition positioned beneath the outlet connection and extending between the adjacent side wall of said chamber at the outlet side thereof and the adjacent side wall of said terminal portion, said partition terminating short of the side wall of said chamber aty the inlet side thereof to permit steam discharging from said inlet connection to pass upwardly, after sharply reversing its direction of flow, to the space above said partition, and a plurality of laminae of wire mesh supported on said partition and defning a plurality of narrow passageways through which steam owlng upwardly after discharge from the terminal portion of said inlet connection must pass in travelling to said outlet con? nection.

3. Apparatus for treating superheated steam comprising a desuperheating chamber having an inlet and an outlet connection, said inlet connection having a terminal portion formed within and extending downwardly in said chamber Ito direct the steam downwardly toward the bottom of said chamber, means to spray water upwardly and counter to the flow of superheated steam entering said chamber through said inlet, partition means disposed in said chamber intermediate said terminal portion and the steam outlet connection and cooperating with the side walls of said chamber to define enlarged passageways at the sides of said terminal portion communieating at their inner ends with the interior of said chamber above the point of discharge of steam from said terminal portion into said chamber, and communicating at their outer ends with said outlet connection, whereby steam passing downwardly through said terminal portion into said chamber is caused to take a sharp reversalfin direction of now upwardly after contact thereof with said water spray before entering said passageways, thereby causing larger particles of water entrained in said steam to separate out and pass to the bottom of said chamber, and bodies of foraminous material positioned in said passageways so that steam must pass through the interstices thereof to said outlet, the extent and disposition of said foraminous material being such that the steam is stripped thereby of any residual moisture and said moisture is at least largely converted into steam by heat transferred from the steam traversing said passageways.

4. Apparatus for treating superheated steam comprising a desuperheating chamber having an inlet and an outlet connection, said inlet connection having ra terminal portion formed within and extending downwardly in said chamber to direct the steam downwardly toward the bottom of said chamber, means to spray water upwardly and counter to the flow of superheated steam entering said chamber through said inlet, partition means disposed in said chamber intermediate said terminal portion and the steam outlet connection and cooperating with the side Walls of said chamber to deiine enlarged passageways at the sides of said terminal portion communieating at their `inner ends with the interior of said chamber above the point of discharge of steam from said terminal portion into said chamber, and communicating at their outer ends with said 4outlet connection,v whereby steam passing downwardly through said terminal portion into said chamber is caused to take a sharp reversal in direction of ilow upwardly after contact thereof with said water spray before entering said passageways, thereby causing larger particles of water entrained in said steam to separate out and pass to the bottom of said chamber, and bodies of foraminous material positioned in said passageways so that steam must pass through the interstices thereof to said outlet, the extent and disposition of said foraminous material being such that the steam is stripped thereby of any residual moisture and said moisture is at least largely converted into steam by heat transferred from the steam traversing said passageways, and said passageways and said foraminous material cooperating to define restricted passages for the steam of a total cross-sectional area greater than the cross-sectional area of said steam inlet.

5. Apparatus for desuperheating steam comprising walls enclosing a. chamber, a steam inlet connection for said chamber having its terminal portion formed within and extending downwardly in said chamber to direct the steam introduced into said chamber downwardly toward the bottom thereof, means arranged adjacent the outlet of said terminal portion for directing a spray of water upwardly into said terminal portion bounter to the downward flow of said steam, a steam outlet connection communicating with the interior of said chamber above and removed from the vicinity of the outlet of said terminal portion, and baille means extending laterally inwardly from the side wall of said chamber beneath said outlet connection toward the outlet of said terminal portion, said baflie cooperating with said terminal portion and the walls of said chamber to define an enlarged space beneath and alongside said terminal portion and also defining a passageway above said bafile leading from said space to said outlet connection, whereby steam passing downwardly through said terminal portion into said enlarged space is caused to take a, sharp reversal in direction of ilow upwardly in owing to said passageway. n

ADOLPH J. WEGMANN.

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