CA1252743A - Steam separating apparatus using a chevron separator and a skimmer - Google Patents

Abstract

STEAM SEPARATING APPARATUS
USING A CHEVRON SEPARATOR AND A SKIMMER

ABSTRACT OF THE DISCLOSURE

A steam separating apparatus wherein a first separating unit receives a steam-water mixture and discharges said mixture in a substantially tangential direction against an impingement plate to separate some water from said mixture.
A second separating unit is disposed in a fluid flow relation to the first separating unit and includes a plurality of plates together formed into a closed circular configuration.
The latter plates are in a chevron configuration to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes through said paths to separate additional water from said mixture. A skimmer is provided over the second separating unit to provide additional separation of water from the steam leaving certain areas of the latter separating unit.

Description

`` ~Z'~7~L3 A-16,076 - STEAM SEPARATING APPARATUS
USING A CHEVRON SEPARATOR AND A SKIMMER

BACXGROUND OF THE INVENTION

This invention relates ~o a steam separating apparatus and, more particularly, to an apparatus for receiving a mixture of liquid and vapor and separating the liquid from the vapor.

In natural circulation vapor generators, mixtures of water and steam rise in heated steam-generating tubes and discharge into one or more large steam drums disposed in an elevated position ahove the tubes. The drums include means to separate the water from the steam with the latter being removed through openings of the upper portions of the drum and the ormer being recirculated through downcomers to the boiler and back to the steam generating tubes to complete the natural circulation loop.

In relatively large installations employing natural circulation vapor generators, it is essential that an eficient separation of the steam from the water be ~ffected 2a in the drum with minimal pressure loss in order to furnish steam of the required purity to the point of use, and steam-free water to the circulation system. To this end, many previous arrangements have used separators ha~ing spiral arms which discharge the steam-water mixture tangentially ~æs~74~
towards the inner wall of a shell, or skirt, to promote the separation. Although satisfactory for most purposes, this type of arrangement, even if combined with another drying stage, does not insure maximum separation and is therefore less than completely desirable for more stringent applications.
SUMMARY OF THE INVENTION
Accordingly, the present invention seeks to provide a steam separating apparatus and a separating unit utilized therein, in which water is separated from the steam-water mixture in multiple stages at a relatively low pressure loss.
Further, the presen invention seeks to provide a separating apparatus and unit of the above type which includes a spiral arm separator for providing a first stage of sepa ration and an additional separator for providing a second stage of separation.
The present invention still further seeks to provide a separator which provides the above-mentioned second stage separation formed by a plurality of chevron, or W-shaped, plates arranged in an inverted frusto-conical configuration.
~Q Still further, the present invention seeks to provide an apparatus and separating unit of the above type in which a skimmer is provided over the second stage separator to provide additional separation of water from the steam-water mixture after the latter is discharged from the second stage separator and before it enters a dryer.
Thus broadly, the invention pertains to a steam separator comprising a plurality of plates having a W-shaped cross-section, the plates being in a nested, spaced-apart relationship to define a plurality of paths of a W-shaped configuration. Means are provided for supporting the plates in a closed circuIar configuration so that a steam-water mixture passing radially inwardly through the paths impinges on the plates to separate water from the mixture. Skimmer ~Z~'~743 means is disposed over the plates for receiving a portion of the mixture passing through the plates and separating additional water from the mixture.
Further, the invention pertains to a steam separator comprising a housing, a plurality of plates disposed in the housing, the plates having a W-shaped cross-section and being in a nested, spaced-apart relationship to define a plurality of paths of a W-shaped configuration, with means for supporting the plates in the housing in a closed circular configuration.
Means are provided for directing a steam-water mixture radially inwardly through the paths so that it impinges on the plates to separaté water from the mixture, the circular configuration having an open upper end to permit the mixture to rise up-wardly in the housing. Skimmer means is disposed in the housing and above the plates for receiving a portion of the mixture and separating additional water from the mixture.
Still further, the invention pertains to a steam separating apparatus comprising a cylindrical housing at least a portion of the upper end of which is open to define ~0 an outlet. Means introduce a steam/water mixture into the housing for flow towards the outlet, first separator means being disposed in the housing upstream of the outlet for receiving the mixture from the introducing means and for separating a portion of the water from the mixture. Second separator means is disposed in the housing between the outlet and the first separator means for receiving the mixture from the first separator means and for separating an additional portion of the water from the mixture, the second separating means being adapted to discharge the mixture in a manner to promote separation of additional water from the mixture.
Skimmer means is disposed in the housing between the second separator means and the outlet for receiving the additional water from the second separator means and for discharging the additional water from the housing.

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Still further, the inventi.on pertains to a steam separating apparatus comprising a plurality of serially arranged units for receiving a steam-water mixture from inlet means and discharging therefrom steam separated from the mixture, the penultimate separating unit comprising a plurality of identical non-planar plates nesting together and formed into a closed annular configuration having effectively inner and outer walls bounding the annular configuration. The walls are defined by opposite edges 1~ of the plates,and the plates are shaped and arranged in a manner to define an annular array of nested irregular parallel and generally radial paths between the pla-tes for the passage of the mixture so that it impinges on the plates as it passes through the paths to separate watex still remaining in the mixture. The last separating unit comprises skimmer means positioned to receive a portion of the mixture emerging from the penultimate separating unit, the skimmer means operating so as to remove additional water from the portion of the mixture.

.
~0 BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description, as well as further aspects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of the presently preferred but nonetheless illustrative embodiment in accordance with the present invention when taken in conjunction with the accompanying drawings in which:

-3a-. .

~Z5'~43 Fig. 1 is a vertical cross-sectional view of the steam separating drum incorporating features of the present invention;
Fig~ 2 is a cross-sectional view taken along the line

2-2 of Fig. l;
Fig. 3 is a cross-sectional view taken along line 3-3 of Fig. 2;
Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 3;
Fig. 5 is a partial cross-sectional view of a portion of the separating apparatus depicted in Fig. 3; and Fig. 6 is a perspective view of a separating unit of the separating apparatus of Fig. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT
PRferring specifically to Fig. 1 of the drawings, the reference numeral 10 rafers in general to the steam processing apparatus of the present invention which includes a steam drum 12 which forms a portion of a natural circulation steam-water system. The drum 12 is of an alongated cylin-drical shape and is disposed with its axis parallel to the horizontal. T~he upper end portions of two groups of steam generating risers or tubes 14 extend through the drum 12 and communicate with the interior of the drum to introduce a mixture of steam and water into the drum. A plurality of downcomers (one o which is shown by the reference numeral 16) extend from the lower portion of the drum to discharge the separated water (along with a quantity of feed wa~er) to 79~

a furnace (not shown) where the water is heated and recycled back through the drum 12. Dried steam is removed from the drum 12 through a plurality of discharge tubes 17 disposed at the upper portion of the drum.

An elongated girth baffle 1~ is provided within the drum immediately above the end portions of the tubes 14 to define a chamber 20 for receiving the mixture of steam and water from the tubes 14. A plurality of separating units 22 are disposed in the drum 12 and are arranged in four hori-20ntally extending rows, two extending to either side of the axis of the drum. Each separating unit 22 includes a riser pipe 24, the lower end portion of which is ~olted to the girth baffle 18 and communicates through an appropriate opening in the baffle with its respective chamber 20 for receivin~ the steam-water mixture from the latter cha~ber 20. Although not clear from the drawings, it is noted that the chamber 20 takes the form of a concentric annulus inside the drum 12 that permits flow from one side of the drum to the other. This annulus is interrupted only by vertical support structure 25 surrounding the openings in the drum 12 for the downcomers 16. Therefore, water can flow through an open girth area in between the latter support structure.

Two horizontally extending feed pipes 26 are disposed in the chamber 20 and are adapted to introduce makeup wa~er into the drum 12 which flows through the separating units 22 with the mixture of steam and water to replenish the supply of steam that is discharged from the separators and, thus, ~5,~t74,3 maintain a constant water level, shown by the reference letter L. This water passes downwardly through a vortex eliminator 28 to the downcomer 16 for discharge back into the natural circulation loop. The vortex eliminator 28 operates in a conventional manner to prevent swirling of the water as it discharges from the drum 12 into the downcomer 1~, and in addition, prevents the steam from being drawn from the upper portion of the drum 12 into the downcomer.
Since the vortex eliminator 28 is of a conventional design, it will not be described in any further detail.

A plurality of steam dryers are disposed in the upper portion of the drum 12 with one being shown by the reference numeral 30 in Fig. 1. The dryers 30 are supported by a conventional support structure in a position immediately above the separating units 22 and immediately below a dry bo~ 32, also of a conventional design. The dryers 30 include a plurality of V-shaped plates (not shown) which are in a nested, but spaced, relationship and may be of the type disclosed in U. S. Patent No. 2,472,101, issued on June 7, 1949. The dryers 30 function to dry the steam dischargin~
from the upper portion of the separating units 22 and separate any entrained water particles carried over with the steam as it flows through the space between the nested plates and through the dry box for discharge from the tubes 17.

Z7~

As shown in Fig. 2, two adjacent xows of separating units 22 are disposed on one side of the axis of the drum 12. The separating units 22 in each row are spaced slightly apart in a horizonal direction with a portion of each separator of a particular row extending partially into the space bet~een adjacent separators of the adjacent row, to minimize the space taken up by the units 22 and thus reduce the length of the drum 12.

Referring specifically to Figs. 3 and 4 which depict the detaiLs oE a separating unit 22, the re~erence numeral 36 refers to an upright cylindrical shell through which the riser pipe 24 extends in coaxial relationship. The riser pipe 24 has a flanged end portion 24a which is bolted to the girth baffle 18 (Fig. 1) and receives a mixture of steam and water from the tubes 14 through a complementary opening formed in the latter baffle. A twisted baffle 37 is provided in the riser pipe 24 to impart a pre-spin to the mixture as it passes upwaxdly through the pipe.

A first-stage separating unit is associated with the pipe 24 and includes a cap 38 extending over the u~per en~ of the latter pipe. A plurality of slots 40 (Fig. 4~ are formed through the upper wall portion of the pipe 24, and a plurality of subs~antially spiral shaped arms 42 are connected to the pipe 24 in registry with the slots 40, respectively, to receive the steam-water mixture from the latter pipe.
The free ends of the arms 42 are open to permit the mixture to discharge therefrom in a substantially tangential direction ~S~7fl~;3 relative to the shell 36. A skirt 44 is provided between the discharge ends of the slots 40 and khe inner wall o~ the shell 36 and is supported in the position shown by a plurality of struts 46.

A chamber 48 is located in the upper portion of the shell 36 and receives a second-stage separating unit 50 for receiving ~he steam-water mixture from the aforementioned first-stage unit. As better shown in Fi~s. 5 and 6, the separating unit 50 is formed by a plurality of plates 52 formed into a chevron, or "~" shaped, cross-sectional con-figuration. The plates 52 are nested within each other with a slight spacing therebetween to define a plurality of irregular W-shaped passages for the steam-water mixture.
The plates 52 extend angularly outwardly as viewed in Fig. 3 to form an inverted frusto-coni_al configuration with addi-tional plates 52a being disposed in the spaces between the upper end portions of the regular plates 52, as better shown in Figs. 5 and 6.

The plates 52 and 52a are secured in the positicn shown between two annular shrouds 54 and 56 which are secured to the respective end portions of the plates, as better shown in Fig. 3. The shroud 54 rests upon the upper portion of the spiral arms 42 and the shroud 56 extends immediately below a hood 58 extending over the upper end of the shell 36 and defining a central opening 60 therein. A plurality of circumferentially spaced openings 62 are provided in the upper end of the shell 36 immediately below the hood 58 for reasons to be explained in detail later.

:~L;2S~Zt~'~3 A third-stage separating unit, in the form of a skimmer 64, extends over the upper portion of the separating unii 50 and includes a cover portion 66 having a central opening 68 and a tapered annular portion 70. A rim 72 extends downwardly from the outer edge of the cover portion 66 and i9 spaced from the upper end portion of the shell 36.

In operation, the mixture of steam and water entering the end portion 24a of the riser pipe 24 of each separator 22 rises in the latter pipe and then passes radially outwardly from the pipe through the slots 40 and into the arms 42 of the first-stage separating unit, where it is directed tangentially against the inner wall of thé skirt 4~, as shown by the flow arrows A. This creates a vortex, or swirling stream of fluid, with the resulting centrifugal forces causing a portion of water in the mixture to flow towards the skirt 44 where it collects on, and flows down, the inner wall of the skirt until it falls through the lower portion of the shell 36, as shown by the flow arrows B. The water thus collected falls by gravity into the reservoir of water disposed above ~0 the girth baffle 1~ (Fig. 1), before passing through the vortex eliminator 28 and into the downcomer 16 for r cir-culation.

The remaining portion of the steam-water mixture from the arms 42, which has a reduced water content by vir~ue of the above initial separation, passes upwardly by virtue of its buoyance, as shown by the flow arrows C, and rises in the chamber 48 before passing in a substantially radial direction _9 _ ~ZS;27~3 through the irregular passages defined by the nested plates 52 and 52a of the second-stage separating unit 50 and into the open central portion of the latter unit, as shown ~y the 10w arrows D. This passage through the plates 52 and 52a causes a further separation of the wa~er from the mixture due to the impringement against the latter plates and the resultant collection of water on the plates. Also, ~he mixture discharges from the passages in a substantial tangential direction, thus creating a vortex, wi~h the resultant centri~ugal forces promoting additional separation as discussed above.
The water thus removed from the mi~ture passes downwardly through an opening in the shroud 54, as shown by the flow arrows E, and through ~he lower portion of the shell 36 where it combines with water discharging from the arms 42 and passes into the drum 12 as discussed above.

The mixture from the central por~ion of the qeparator 50 which is substantially steam, passes upwardly in the shell 36 and discharges through the opening 60 in the hood 58. A majority of this mixture passes through the opening 70 in the skimmer 64 to the dryers 30, as shown by the flow arrows F, while the remaining portion flows underneath the skimmer between the skimmer and the hood 58 before it impinges against the rim 72 of the skimmer, as shown by the flow arrows G. This induces further separation of water from the mixture and the former falls downwardly into the lower portion of the drum and the latter passes upwardly to the dryers 30 ~Fig. 1).

--10~

~25Z~.3 A portion of the mixture entering the chamber 4~ from the spiral arms 42 will pass directly to the upper portion of the shell 36 outside the separating unit 50 and discharge through the openings 62 in the upper end portion of the shell before impinging against the rim 72 with the same result as discussed above.

~ Thus, a multi-stage SeQaratiOn process is achieved, initially through the spiral arms 42, against the skirt 44, and then through the plates 52 of the separating unit 50, and~or against the rim 72 of the skimmer 6~, with a final drying occurring in the dryers 30.

As a result of the above, a great maJority of the water is remov~d from the mixture of steam and water entering the end portion 24a of the riser pipe 24 associated with each separator.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention therein.

Claims (52)

WHAT IS CLAIMED IS:

1. A steam separator comprising a plurality of plates having a W-shaped cross-section, said plates being in a nested, spaced-apart relationship to define a plurality of paths of a W-shaped configuration, means for supporting said plates in a closed circular configuration so that a steam-water mixture passing radially inwardly through said paths impinges on said plates to separate water from said mixture, and skimmer means disposed over said plates for receiving a portion of the mixture passing through said plates and separating additional water from said mixture.

2. The separator of claim 1 wherein said skimmer means comprises a cover plate extending over said W-shaped plates in a spaced relationship to said plates for defining a passage for said mixture, and a rim supported by said cover plate against which said mixture impinges to separate said additional water from said mixture.

3. The separator of claim 2 wherein said cover plate has a central opening through which the remaining portion of said mixture passes as it discharges from said separator.

4. The separator of claim 2 further comprising a shell extending around said plates, the upper end portion of said shell having a plurality of openings formed therein to permit a radial discharge of a portion of aid mixture, said rim disposed in the path of the mixture discharging through said latter openings for separating water from said latter mixture.

5. The separator of claim 1 wherein said plates together form a frusto-cone.

6. The separator of claim 1 wherein said supporting means comprises a shroud disposed at the respective ends of said plates.

7. The separator of claim 1 wherein said mixture discharges from said paths in a direction substantially tangential to the inner wall of said separator.

8. The separator fo claim 1 further comprising a shell extending around said plates, and an additional separator disposed in said shell immediately below said plates.

9. The separator of claim 8 wherein said additional separator comprises a central pipe for receiving said mixture, and a plurality of spiral arms communicating with said pipe for receiving said mixture from said pipe and discharging said mixture in a substantially tangential direction relative to said shell for initially separating water from said mixture.

10. The separator of claim 9 further comprising a skirt disposed in the path of said mixture as it discharges from said arms for promoting said separation.

11. The separator of claim 9 wherein the mixture from said additional separator passes upwardly in said shell and forms the mixture passing through the paths defined by said plates.

12. A steam separating apparatus comprising a first separating unit for receiving a steam-water mixture and discharging said mixture in a substantially tangential direction relative to an impingement plate to separate some water from said mixture; a second separating unit disposed in a fluid flow relation to said first separating unit for receiving said mixture from said first separating unit, said second separating unit comprising a plurality of plates together formed into a closed circular configuration, said plates being shaped in a manner to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes through said paths to separate additional water from said mixture, and a third separating unit extending over said second separating unit, said third unit comprising a cover plate extending over said plates in a spaced relationship to said plates for defining a passage for the mixture discharging from said second separating unit, and a rim supported by said cover plate against which said mixture impinges to separate said additional water from said mixture.

13. The apparatus of claim 12 wherein said first separating unit comprises a riser pipe communicating with said inlet means for receiving said mixture, baffle means disposed in a spaced relation to said riser pipe, at least one discharge slot formed through said riser pipe, and an arcuate shaped discharge member registering with each slot for receiving said mixture and discharging it against said baffle means to promote the separation of water from said mixture, said water collecting on said baffle means and falling by gravitational forces and said mixture rising by buoyant forces.

14. The apparatus of claim 12 wherein said plates are supported by said first separating unit.

15. The apparatus of claim 12 wherein said mixture discharges from said paths in a direction substantially tangential to the inner wall of said second separating unit.

16. The apparatus of claim 12 wherein each of said plates and said paths have a W-shaped configuration and said plates together are formed into-an inverted frusto-conical configuration.

17. The apparatus of claim 12 wherein said cover plates have a central opening through which the remaining portion of said mixture passes as it discharges from said separator.

18. The apparatus of claim 12 further comprising a shell extending around said plates, the upper end portion of said shell having a plurality of openings formed therein to permit a radial discharge of a portion of said mixture, said rim disposed in the path of the mixture discharging through said latter openings for separating water from said mixture.

19. The apparatus of claim 12 wherein said plates together are formed into an inverted frusto-conical configuration.

20. A steam separating apparatus comprising a cylindrical drum having inlet means for receiving a mixture of steam and water from an external source; first outlet means disposed in the lower portion of said drum for discharging said water; second outlet means disposed in the upper portion of said drum for discharging said steam; and a plurality of steam separating units disposed in said drum, each unit comprising a first-stage separator for receiving said steam-water mixture and discharging said mixture in a substantially tangential direction relative to an impingement plate to separate some water from said mixture; a second-stage separator disposed in a fluid flow relation to said first-stage separator for receiving said mixture from said first-stage separator, said second-stage separator comprising a plurality of plates together formed into a closed circular configuration, said plates being shaped in a manner to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes through said paths to separate additional water from said mixture, and a third-stage separator extending over said second-stage separator, said third-stage separator comprising a cover plate extending over said plates in a spaced relationship to said plates for defining a passage for the mixture discharging from said second-stage separator, and a rim supported by said cover plate against which said mixture impinges to separate said additional water from said mixture.

21. The apparatus of claim 20 wherein said first-stage separator comprises a riser pipe communicating with said inlet means for receiving said mixture, baffle means disposed in a spaced relation to said riser pipe, at least one discharge slot formed through said riser pipe, and an arcuate shaped discharge member registering with each slot for receiving said mixture and discharging it against said baffle means to facilitate the separation of water from said mixture, said water collecting on said baffle means and falling by gravitational forces and said mixture rising by buoyant forces.

22. The apparatus of claim 20 wherein said plates are supported by said first stage separator.

23. The apparatus of claim 20 wherein steam from said mixture discharges from said paths in a direction substantially tangential to the inner wall of said second-stage separator.

24. The apparatus of claim 20 wherein each of said plates and said paths have a W-shaped configuration and said plates together are formed into an inverted frusto-conical configuration.

25. The separator of claim 20 wherein said cover plate has a central opening through which the remaining portion of said mixture passes as it discharged from said separator.

26. The apparatus of claim 20 further comprising a shell extending around said plates, the upper end portion of said shell having a plurality of openings formed therein to permit a radial discharge of a portion of said mixture, said rim disposed in the path of the mixture discharging through said latter openings for separating water from said latter mixture.

27. The apparatus of claim 20 wherein said plates together are formed into an inverted frusto-conical configuration.

28. The apparatus of claim 20 wherein said drum is oriented in a horizontal direction and wherein said separators are disposed along the length of said drum with their respective riser pipes extending in a vertical direction.

29. The apparatus of claim 28 wherein said separators are arranged into a plurality of rows, the separators in each row extending in a spaced relationship along the length of said drum.

30. The apparatus of claim 29 wherein there are two rows of separators disposed on both sides of the axis of said drum.

31. The apparatus of claim 28 wherein a portion of each separator of a particular row extends partially into the space between adjacent separators of the adjacent row.

32. A steam separator comprising a housing, a plurality of plates disposed in said housing, said plates having a W-shaped cross-section and being in a nested, spaced-apart relationship to define a plurality of paths of a W-shaped configuration, means for supporting said plates in said housing in a closed circular configuration, means for directing a steam-water mixture radially inwardly through said paths so that it impinges on said plates to separate water from said mixture, said circular con-figuration having an open upper end to permit said mixture to rise upwardly in said housing, and skimmer means disposed in said housing and above said plates for receiving a portion of the mixture and separating additional water from said mixture.

33. A steam separator apparatus comprising a housing, a first separating unit in said housing, said first separating unit comprising an impingement plate disposed in said housing, means for receiving a steam-water mixture and discharging said mixture in a substantially tangential direction relative to said impingement plate to separate some water from said mixture; a second separating unit disposed in said housing above said first separating unit and in a fluid flow relation to said first separating unit for receiving said mixture from said first separating unit, said second separating unit comprising a plurality of plates together formed into a closed circular config-uration, said plates being shaped in a manner to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes through said paths to separate additional water from said mixture, and a third separating unit disposed in said housing and extending over said second separating unit, said third separating unit comprising a cover extending over said plates in an axially-spaced relationship to said plates for defining a passage for the mixture discharging from said second separating unit, and a rim supported by said cover in a radially spaced relation to said plates against which said mixture from said paths impinges to separate said additional water from said mixture.

34. A steam processing apparatus comprising a cylindrical drum having inlet means for receiving a mixture of steam and water from an external source; first outlet means disposed in the lower portion of said drum for discharging said water; second outlet means disposed in the upper portion of said drum for discharging said stream; and a plurality of steam separating units disposed in said drum, each unit comprising a housing; a first-stage separator disposed in said housing for receiving said steam-water mixture and discharging said mixture in a substantially tangential direction relative to an impingement plate to separate some water from said mixture;
a second-stage separator disposed in said housing above, and in a fluid flow relation to said first-stage separator for receiving said mixture from said first-stage separator, said second-stage separator comprising a plurality of plates together formed into a closed circular configuration, said plates being shaped in a manner to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes radially through said paths to separate additional water from said mixture, and a third-stage separator disposed in said housing and extending over said second-stage separator, said third-stage separator comprising a cover extending over said plates in an axially-spaced relationship to said plates for defining a passage for the mixture discharging from said second-stage separator, and a rim supported by said cover in a radially spaced relation to said plates against which said mixture from said paths impinges to separate said additional water from said mixture.

35. A steam separator comprising a housing, means including an inlet and an outlet for directing a steam-water mixture through said housing, a plurality of plates disposed in said housing, said plates having a W-shaped cross-section and being in a nested, spaced-apart relationship to define a plurality of passages of a W-shaped configuration, means for supporting said plates in said housing in an open-ended closed circular configuration in the flow path of said steam-water mixture so that the mixture impinges on said plates to separate water from said mixture and then rises upwardly in said housing, a cover extending over said W-shaped plates in an axially spaced relationship to said plates and having a central opening for directing a portion of said mixture through said outlet, and a rim supported by said cover in a radially spaced relation to said plates against which the remaining portion of said mixture impinges to separate additional water from said mixture.

36. A steam separator apparatus comprising a housing, a first separating unit in said housing, said first separating unit comprising an impingement plate disposed in said housing, means for receiving a steam-water mixture and discharging said mixture in a substantially tangential direction relative to said impingement plate to separate some water from said mixture; a second separating unit disposed in said housing above said first separating unit and in a fluid flow relation to said first separating unit for receiving said mixture from said first separating unit, said second separating unit comprising a plurality of plates together formed into a closed circular configur-ation, said plates being shaped in a manner to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes through said paths to separate additional water from said mixture, and a third separating unit disposed in said housing and comprising a cover extending over said plates in an axially spaced relationship to said plates and having a central opening for directing a portion of said mixture through said outlet, and a rim supported by said cover in a radially spaced relation to said plates against which the remaining portion of said mixture impinges to separate said additional water from said mixture.

37. A steam separator comprising a housing, having an inlet and an outlet, means for directing a steam-water mixture through said housing, a plurality of plates disposed in said housing, said plates having a W-shaped cross-section and being in a nested, spaced-apart relationship to define a plurality of passages of W-shaped configuration, means for supporting said plates in said housing in an open-ended closed circular configuration in the flow path of said steam-water mixture so that the mixture impinges on said plates to separate water from said mixture and then rises upwardly in said housing, means including a cover extending over said W-shaped plates in an axially spaced relationship to said plates for dividing the flow of mixture leaving the plates into two paths, said cover having a central outlet for a portion of said mixture flowing in one flow path, and a rim supported by said cover and positioned and arranged in said other flow path so that the remaining portion of said mixture leaving said plates impinges against said rim, to separate additional water from said mixture.

38. A steam separator apparatus comprising a housing, a first separating unit in said housing, said first separat-ing unit comprising an impingement plate disposed in said housing, means for receiving a steam-water mixture and discharging said mixture in a substantially tangential direction relative to said impingement plate to separate some water from said mixture; a second separating unit disposed in said housing above said first separating unit and in a fluid flow relation to said first separating unit for receiving said mixture from said first separating unit, said second separating unit comprising a plurality of plates together formed into a closed circular configur-ation, said plates being shaped in a manner to define a plurality of irregular paths for the passage of said mixture so that said mixture impinges on said plates as it passes through said paths to separate additional water from said mixture, and a third separating unit disposed in said housing and comprising means including a cover extend-ing over said plates in an axially spaced relationship to said plates for dividing the flow of mixture leaving the plates into two flow paths, said cover having a central outlet for a portion of said mixture flowing in one flow path, and a rim supported by said cover and positioned and arranged in said other flow path so that the remaining portion of said mixture leaving said plates impinges against said rims to separate said additional water from said mixture.

39. A steam separator comprising a housing having an inlet for receiving a steam-water mixture which flows through said housing, a plurality of plates disposed in said housing, said plates having a W-shaped cross-section and being in a nested, spaced-apart relationship to define a plurality of passages of a W-shaped configur-ation, means for supporting said plates in said housing in an open-ended closed circular configuration in the flow path of said steam-water mixture so that the mixture impinges on said plates to separate water from said mixture and then rises upwardly in said housing, a cover extending over said W-shaped plates in an axially spaced relationship to said plates in the flow path of said mixture as it rises from said plates to deflect a first portion of said mixture in a radial direction, said cover having a central outlet in said latter flow path for discharging a second portion of said mixture from said housing, a rim supported by said cover and positioned and arranged in a radially spaced relation to said cover and in the flow path of said first portion of said mixture so that it impinges against said rim to separate additional water from said first portion of said mixture.

40. A steam separating apparatus comprising a cylindrical housing at least a portion of the upper end of which is open to define an outlet, means for introducing a steam/water mixture into said housing for flow towards said outlet, first separator means disposed in said housing upstream of said outlet for receiving said mixture from said introducing means and for separating a portion of said water from said mixture, second separator means disposed in said housing between said outlet and said first separator means for receiving said mixture from said first separator means and for separating an additional portion of said water from said mixture, said second separating means adapted to discharge said mixture in a manner to promote separation of additional water from said mixture, and skimmer means disposed in said housing between said second separator means and said outlet for receiving said additional water from said second separator means and for discharging said additional water from said housing.

41. The apparatus of Claim 40 wherein said outlet and said skimmer means are located above said second separator means and wherein said second separator means is located above said first separator means, said mixture passing upwardly in said housing through said first separator means to said second separator means and then to said outlet and said skimmer means.

42. The apparatus of Claim 40 wherein said housing has an additional outlet for discharging the water separated by said first and second separator means.

43. The apparatus of Claim 40 wherein said second separator means comprises a plurality of plates disposed in said housing, said plates having a W-shaped cross-section and extending in a nested, spaced-apart relationship to define a frusto-cone having a plurality of passages of a W-shaped configuration.

44. The separator of Claim 43 wherein said plates are constructed and arranged so that said mixture discharges from said passages in a direction substantially tangential to the inner wall of said frusto-cone to create a vortex and promote said separation of said additional water from said mixture.

45. The apparatus of Claim 43 wherein said mixture passes in a radial direction from the exterior of said frusto-cone, through said plates and into the interior of said frusto-cone so that the mixture impinges on said plates to separate water therefrom and then discharges from the center of said frusto-cone in a substantially tangential direction thus creating a vortex which promotes said separation of said additional water.

46. The apparatus of Claim 40 wherein said first separator means further comprises a plurality of spiral arms for receiving said mixture and discharging said mixture in a substantially tangential direction relative to said housing for initially separating water from said mixture before said mixture rises to said second separator means.

47. The separator of Claim 46 wherein said introducing means comprises an inlet pipe extending into said housing for receiving said mixture and directing it to said spiral arms.

48. The separator of Claim 46 further comprising a skirt disposed in a radially spaced relation to said spiral arms in the path of said mixture as it discharges from said arms for promoting said separation.

49. The apparatus of Claim 40 wherein said skimmer means extends over the upper end of said housing in an axially spaced relationship to said second separator means in the flow path of said mixture as it discharges from said outlet to deflect said additional water in a radial direction, said skimmer means having a central outlet disposed in a coaxially spaced relationship to said housing outlet for discharging the remaining portion of said mixture from said housing.

50. The apparatus of Claim 49 wherein said skimmer means includes a rim extending externally of said housing in a radially spaced relation to said housing and extending parallel to the upper end portion of said housing so that said portion of said mixture impinges against said rim to separate said additional water.

51. The apparatus of Claim 50 wherein the upper end portion of said housing has a plurality of openings formed therein to permit a radial discharge of a portion of said mixture, said rim disposed in a radially spaced relation to said openings.

52. A steam separating apparatus comprising a plurality of serially arranged units for receiving a steam-water mixture from inlet means and discharging therefrom steam separated from said mixture, the penultimate separating unit comprising a plurality of identical non-planar plates nesting together and formed into a closed annular configuration having effectively inner and outer walls bounding the annular configuration, said walls being defined by opposite edges of the plates, said plates being shaped and arranged in a manner to define an annular array of nested irregular parallel and generally radial paths between the plates for the passage of said mixture so that it impinges on said plates as it passes through said paths to separate water still remaining in said mixture and the last separating unit comprising skimmer means positioned to receive a portion of the mixture emerging from said penultimate separating unit, said skimmer means operating so as to remove additional water from the said portion of the mixture.