CA1077412A

CA1077412A - Cyclone separator for a steam/water mixture

Info

Publication number: CA1077412A
Application number: CA272,665A
Authority: CA
Inventors: Fritz Laubli
Original assignee: Gebrueder Sulzer AG
Current assignee: Sulzer AG
Priority date: 1976-03-26
Filing date: 1977-02-25
Publication date: 1980-05-13
Also published as: ZA77496B; AU2164977A; BE852894A; AU508124B2; FI60976C; JPS52118672A; SE419124B; FI770494A; PL196825A1; JPS5724182B2; PL107717B1; SE7703340L; DE2615520C2; FI60976B; DE2615520A1; CH611176A5

Abstract

ABSTRACT OF THE DISCLOSURE

A cyclone-type separator for separating water from a steam/water mixture. The separator is of the type of an upright, generally cylindric vessel whose upper portion defines a steam zone, the lower portion defining a water zone. A
separation zone into which the steam/water mixture is normally introduced in tangential fashion, is located between the two former zones. A conduit communicates the interior of the separator at the steam zone with the interior of same slightly above the top level of the water zone, to return a film of water formed on the inside wall of the separator and rising towards the top thereof. Thus, the film of water is returned through said conduit back to the proximity of the water zone top level to increase the separation efficiency of the device.

Description

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The invention relates to a water separator of the cyclon type for a steam/water mixture with a vesseI having a vertical axis. It encloses a steam space with its upper zone, a water space with its lower zone and a separator zone in between. The steam/water mixture enters tangenially into the separator zone. The vessel is provided with one outlet each, at least, in the zone of the steam space as well-as the water space.
With a water separator of th-is kind the water injected ; 10 ~ against the wall of the vessel rushes along this wall downwards into the water space while the steam streams upwards into the-steam space. Tests with such water separators have shown that a water film not visible under normal conditions can spread -upwards along-the--vessel-wall.- This--water film---~can be pushed to the steam outlet by the-steam flow the pattern of which is not fully known yet. There it can be entrained by the strong stream forces of the steam along the wall of the pipe connected to the outlet or it can be carried away in droplet form by the steam. Thus the separating efficiency of these water separators is unsatisfactory for various applications.
It is an object of the invention to improve the separating efficiency of the above mentioned water separators in a simple and effective way.
According to the invention, the separator is provided ; with at least one channel for sucking off the water which spreads as a film over the vessel wall enclosing the steam space;
its entrance is between the mi2ture inlet and steam outlet at the inner vessel wall and its exit is in the vessel in a zone below the mixture inlet and above the water outlet. Through this configuration of the water separator a bypass is created for the water where the water film rising along a helical path is sucked off by means of a part of the steam flow and is returned to a lower zone of the water separator. The water t~ ~

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entering into the suction channel thus flows into this channel not only under the influence of gravity but is also pulled into the suction channel by the forces of the streaming steam.
Two examples of the invention are explained in detail in the following description on hand of a drawing. It is shown:
Fi~ 1 A water separator according to the invention partially in front view, partially in axial section.
Fig. 2 An axial section of the upper part of a modified water separator and Fig. 3 A section of the separator according to Fig.

2 showing the zone of the mixture inlet in plan.
According to Fig. 1 the water separator shows an upwardly elongated cylindrical vessel 1 having a vertical axis.
The vessel 1 is composed of a pipe section 7, an upper hemispher-; ical end 2 and a lower hemispherical end 3. At the upper end , of the vessel 1 an axial steam exit connector 4 is provided which penetrates the hemispherical bottom 2. The lower end of connector 4 extends some distance into the interior of the vessel.
The lower hemispherical end 3 is provided with a central manhole ~20 connector 5 which is closed by a cover 15. At the inside of thecover 15, baffles 8 are provided in order to destroy the rotating flow of the li~uid locally. The hemispherical bottom 3 carries a water outlet 13 to which an outlet line 12 is connected approximately tangentially.
The vessel 1 has in its lower portion or zone, which extends about to the dashed line A, the water space of the separator while a separation zone extends from the line A to .:
about the dashed line B. The upper end of the vessel encloses the steam space of the separator. In the separation zone an inlet 11 is provided in a wall section 7 for introducing the steam/water mixture to be separated. A feed line 10 is connected to the inlet approximately tangentially.

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According to the invention,,the separator is provided with a sucti~n channel which has the form of a pipe 20 extending along the'outside 'of the vessel 1. The inlet opening 21 of the suction line 20 is disposed in the vessel wall between the inlet 11 and the steam outlet connector 4. The suction line 20 terminates in an exit opening 22 located in the vessel wall below the mi~ture inlet 11 and above the water outlet 13, some-what above the water space. The vertical distance a of the inlet 21 from the mixture inlet 11 is smaller than the vertical .
distance (b) of the outlet 22 of the suction line 20 from the mixture inlet 11. The suction line 20 makes it possible to prevent water which spreads as a film from the separating zone upwards along the vessel wall to rise beyond the opening 21.
The film-like rising water is now drawn by a part of the steam flow into the suction line 20 and is returned to the vessel near the lower end of the separating zone.
In the example according to Fig.'2 and 3 which is ,~~~-~~~~~ designed like the example according to Fig. 1 with respect to the arrangement of the separator vessel 1, the ' 20 suction channel is arranged inside the vessel 1 and is formed by the vessel wall and a liner sheét 30 placed inside the vessel.
~r~ In the zone of the liner sheet 30 several, e.g. 8, spacer strips ' 31 are provided which are distributed uniformly over the circum-~,~, ference of the ~essel and are welded to the vessel. The spacer strips 31 define an approximately helical course descending in ,~ the rotating direction of the steam/water mixture. The liner ; sheet 30 is fastened to the spacer strips by spot welds not shown. In the zone of the mixture inlet 11 the liner sheet 30 i8 perforated and the edge 33 of the so formed opening of the ' 30 liner sheet is bent outwards so that the edge contacts the ,~ .
vessel wall near the opening 11. A welded seal between this edge and the vessel wall is~usually not necessary.
The upper edge 32 of the liner sheet 30 is flanged -~ 3 --10~7412 somewhat to the outside resulting in a narrowed gap ,~
as inlet opehing o~ the suction channel. This narrowing produces in the gap a higher steam veIocity which secures the entrainment of the water rising along the liner sheet. The axial length of the liner sheet in Fig. 2 is about l.S-times the - inner diameter of`the liner sheet. In general one would not go beyond 4-times the inner diameter.
Many other variants of the present invention are readily conceivable. For instance it is possible to arrange the steam outlet connector 4 end flush with the hemispherical bottom 2 so that the connector section extending into the interior of the vessei is avoided. Furthermore, it is possible to install one or several tangential or radial outlet connectors on the vessel. Likewise, instead of one mixture inlet linë 10, several such lines can be connected to the vessel either on the same level or at different levels. Then the respective vertical distance of the inlet opening and the outlet opening of the suction channel from the mixture inlet is measured between the uppermost inlet opening of the mixture and the inlet of the suction channel or between the lowermost inlet opening of the mixture and the exit of the suction channel.
; Furthermore, in the example according to Fig. 1 also two or three suction lines, distributed over the circumference of the vessel, can be provided instead of one suction line 20.
These and other modifications, however, do not depart from the scope of this invention as defined in the accompanying claims.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Water separator of the cyclone type for a steam/
water mixture with a vessel having a vertical axis, said vessel having an upper zone defining a steam space, and a lower zone defining a water space, said vessel further having an inter-mediate zone between the former two, said intermediate zone defining means for introducing the steam/water mixture tangen-tially into the separator zone, the vessel being provided in the zone of the steam space and in the zone of the water space with at least one outlet each, wherein at least one suction channel is provided for the removal of water spreading in a film-like fashion over the vessel wall enclosing the steam space; an inlet of said suction channel being located at the inner wall of the vessel between the mixture inlet and the steam outlet, the outlet of said suction channel being located inside the vessel in a zone below the mixture inlet and above the water outlet.

2. Separator according to claim 1 wherein the suction channel is a conduit communicating with the interior of the vessel and extending exteriorly of said vessel.

3. Separator according to claim 1, wherein a liner sheet is arranged at a radial spacing from the inside wall of the vessel and perforated in the zone of the mixture inlet, to define the suction channel by a generally annular space between said liner sheet and the wall of said vessel.

4. Separator according to claim 1, characterized in that the vertical distance of the inlet opening of the suction channel from the mixture inlet is smaller than the vertical distance of the outlet opening of the suction channel from the mixture inlet.

5. Separator according to claim 2, characterized in that the inlet of said conduit is generally tangential relative to said vessel, the remaining portion of said conduit extending generally in the direction of rotation of the steam-water mixture inside said vessel.

6. Separator according to claim 5, wherein the outlet of said conduit is disposed generally tangentially relative to said vessel, whereby the medium flowing in the conduit enters the vessel generally in the direction of rotation of the steam/water mixture inside the vessel.

7. Sparator according to claim 3, characterized in that the spacer sheet is fixedly secured to a plurality of spacer strips, said spacer strips being disposed about the inside periphery of said vessel and being welded to said vessel.

8. Separator according to claim 7 characterized in that the liner sheet is secured to the spacer strips by spot welds.

9. Separator according to claim 3, wherein the vertical length of the liner sheet is at least 1.5-times the inside diameter of the liner sheet.