JP2004089964A - Apparatus and method for separating liquid film in pipeline - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for separating a liquid film in a pipeline, by which moisture can be removed efficiently from vapor containing a large quantity of moisture. <P>SOLUTION: This apparatus is provided with a capturing means 4 arranged circularly in the inner periphery of the pipeline 2 for transferring a gas stream A containing a liquid droplet C, a pressure reducing means 10 arranged on the downstream side of the means 4 in the pipeline 2, a discharge means 16 for discharging the droplet C captured from the gas stream A by the means 4 to the outside of the pipeline 2 and a gas stream returning means 18 for returning the liquid droplet-removed gas stream to the downstream side of the means 10. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for removing water from a gas stream containing a large amount of water in a pipe, and more particularly, to a method for removing water contained in steam in an outlet pipe of a blowdown heat recovery tank of a steam generator. TECHNICAL FIELD The present invention relates to a liquid membrane separation device and a method for removing water.
[0002]
[Prior art]
When transferring steam containing a large amount of water in many plants, it is necessary to remove the water contained in the steam from the convenience of the transfer destination process and the structural problems of the piping. For example, at the outlet pipe of a blow-down heat recovery tank connected to the steam generator of a pressurized water nuclear power plant, a large amount of water may be contained in the steam, and when this water content is large, pressure pulsation occurs in the piping system. And the entire system including the tank may become unstable. In addition, although water and steam should have been separated in the heat recovery tank, a large amount of water remains in the steam, resulting in poor separation efficiency in the heat recovery tank and the purification capacity of the plant. May decrease. As described above, it has been desired to remove water contained in steam in order to prevent a stable system without pressure fluctuation, prevent a decrease in purification efficiency, and further reduce the size of a heat recovery tank.
[0003]
Therefore, for example, as shown in FIG. 5, a plurality of triangular guide plates 102 are provided inside the gas transfer pipe 100 such that the tops have a substantially conical shape with the top directed toward the axially upstream side of the pipe, and A centrifugal force type separation member 101 is arranged around the central axis of the pipe so as to be oblique to the diameter of the pipe, and is arranged at intervals in the circumferential direction. On the downstream side of the force-type separating member 101, there is a liquid collecting device for separating liquid droplets from a gas containing liquid droplets as provided with an annular liquid collecting member 103 (for example, see Patent Document 1). . In this way, the gas A including the droplets flows while rotating by the centrifugal force type separation member 101, and a centrifugal force is applied. At this time, the droplet collides with the guide plate 102 to form a liquid film C, flows downstream along the inner wall of the pipe, is collected by the liquid collecting member 103, and is discharged through the discharge pipe 104. It is discharged to the trap 105. The gas passes through the opening of the liquid collecting member 103 as shown by the dotted line B and flows further downstream, so that the droplet is removed from the gas flow including the droplet. It has become.
[0004]
[Patent Document 1]
JP-A-10-128024 (Abstract, FIG. 2)
[0005]
[Problems to be solved by the invention]
However, the liquid film C flowing along the inner wall of the pipe 100 only flows into and is collected by the liquid collecting member 103 as a natural flow accompanying the flows of the gas flows A and B. There was a problem that the removal efficiency was poor. Further, there is a problem that the liquid film C collides with the entrance of the liquid collecting member 103 or gets over the entrance, and the liquid film C is scattered to the mainstream side, so that the efficiency of removing the liquid film is further deteriorated. There was a point.
[0006]
Accordingly, the present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a liquid film separation apparatus and method for piping capable of efficiently removing water from a gas stream containing a large amount of water. The main purpose is to
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a liquid film separation apparatus for a pipe according to the present invention according to claim 1, wherein a capturing means annularly disposed on an inner circumference of a pipe for transferring a gas flow containing droplets, A pressure reducing means disposed downstream of the capturing means inside the pipe, and a discharging means for discharging droplets separated from the gas stream containing the liquid droplets captured by the capturing means to the outside of the pipe; And a gas flow returning means for returning a gas flow obtained by separating droplets from the gas flow containing the liquid droplets captured by the capturing means to a downstream side from the pressure reducing means.
[0008]
Furthermore, a separation / recovery for disposing a gas flow including the droplets, which is disposed outside the pipe and captured by the capturing unit, and separating the gas flow including the droplets into a droplet and a gas flow. It is preferable that a means is provided, and the discharge means and the vapor return means are connected to the separation and recovery means. Further, the trapping means includes an outer annular trapping means for drawing in a liquid film composed of a collection of droplets flowing down the downstream along the inner periphery of the pipe and a gas flow present on the inner peripheral side of the liquid film. A double retraction structure with an inner annular catching means for retraction is also possible. Further, it is preferable that the pipe is connected to a liquid recovery tank, and the liquid droplets discharged by the discharge means are collected in the liquid recovery tank. Furthermore, it is preferable that the capturing means is provided in a plurality of stages in the pipe. In this case, the gas flow returning means corresponding to each stage other than the last stage is disposed so as to return the gas flow to the downstream side of the capturing unit of the next stage provided further downstream. In addition, it is also preferable that the pressure reducing means is an orifice, and that a liquid membrane separator for piping is installed downstream of a curved portion in the piping.
[0009]
According to another aspect of the present invention, there is provided a method of separating a liquid film for a pipe, comprising: (i) a capturing means provided in an annular shape on an inner circumference of the pipe for transferring a gas flow containing droplets; Drawing in a gas stream containing the droplets along the flow path; and (ii) separating the droplets from the gas flow containing the droplets drawn in by the capturing means, discharging the separated gas flows to the outside of the pipe, and discharging the droplets. Returning the separated gas stream to a lower pressure position downstream of the capturing means.
[0010]
[Action]
Since the gas flow returning means connected to the trapping means communicates downstream from the pressure reducing means provided in the pipe, a pressure difference is generated between the gas flow drawing-in position and the gas flow returning position, Due to the pressure difference, the gas flow including the droplets is forcibly sucked in the trapping means, and the efficiency of removing the liquid film is increased.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.
FIG. 1 is a schematic diagram showing a first embodiment of a liquid membrane separator for piping 1 according to the present invention. In this figure, a capturing device 4 functioning as capturing means is provided in a pipe 2. The capturing device 4 is attached in an annular shape along the inner wall of the pipe 2, and an annular portion 6 arranged concentrically with the pipe has an annular shape between the annular portion 6 and the inner wall of the pipe 2. An acquisition unit 8 is defined. An orifice 10 functioning as a pressure reducing member is disposed downstream (in FIG. 1, on the right side of the drawing) of the gas flow direction of the pipe 2.
[0012]
A pipe 12 is connected to a part of the capturing device 4, and the gas flow including the droplets captured by the capturing device 4 is recovered to a recovery container 14 functioning as a separating and recovering unit via the pipe 12. You. The collection container 14 is located outside the pipe 2. The gas stream containing the droplets is separated into droplets and a gas stream from which the droplets have been removed in the collection container 14, and the droplets are discharged through a pipe 16 functioning as a discharging unit. Is returned to the inside of the pipe 2 through the pipe 18 functioning as a gas flow returning means. Here, the pipe 18 is configured to communicate with the pipe 2 downstream of the orifice 10 in the gas flow direction.
[0013]
The operation of the liquid film separation apparatus 1 for piping configured as described above will be described. Inside the pipe 2, the liquid film C flowing along the inner wall of the pipe formed by various actions from the droplets contained in the gas flow A flows in the same direction as the flow direction of the gas flow A. It is drawn into the annular capturing portion 8 of the capturing device 4. At this time, a part of the gas flow A, which is the main stream, together with the liquid film C is also drawn in from the annular capturing portion 8 at the same time. A part of the gas flow A drawn by the capturing device 4 and the liquid film C are collected in the collection container 14 via the pipe 12. Then, the collection container 14 separates the gas flow A including the liquid droplets and the liquid film C into a liquid and a gas flow from which the liquid has been removed, discharges the liquid to the outside via the pipe 16, and discharges the gas flow. It is returned to the pipe 2 via the pipe 18.
[0014]
Here, the position where the pipe 18 is connected to the pipe 2 is sufficiently lower than the position where the trapping device 4 is provided because the pressure drop effect at the orifice is provided in addition to the pressure loss of the annular trapping device itself. Pressure. That is, in the trapping section 8, the gas flow A and the liquid film C do not flow in spontaneously due to the flow of the main gas flow A inside the pipe 2, but communicate with each other through the pipes 12 and 18. The pressure is forcibly sucked due to the pressure difference with the part. Therefore, the efficiency of removing the liquid film C is increased as compared with the conventional apparatus. It is more efficient to use a guide vane to flow the liquid film to the inner wall side of the pipe 2. Further, if a piping having a curved portion such as an L-shape is used and the liquid membrane separator for piping according to the present invention is mounted downstream of the curved portion, the pipe is included in the gas flow by the action of centrifugal force in the curved portion. Since the droplets to be adhered to the wall form a liquid film, there is an effect similar to that of the guide vane.
[0015]
Next, a second embodiment of the liquid membrane separator for piping according to the present invention will be described with reference to FIG. In the first embodiment, only one stage of the capturing device 4 for capturing the gas flow and the liquid film is provided. In the second embodiment, the liquid film separating device 20 for piping includes the capturing device 4a. And 4b are arranged in two stages in series, that is, a multi-stage liquid membrane separator for piping. The configuration of each step is basically the same as that of the first embodiment, and the capturing devices 4a and 4b communicate with the collection containers 14a and 14b via the pipes 12a and 12b, respectively. And the water separated in 14b are discharged to the outside via pipes 16a and 16b. The gas stream from which water has been removed in the recovery vessel 14b of the second stage is returned to the downstream side of the orifice 10 of the main pipe 2 via the pipe 18b, as in the first embodiment. However, the gas flow from which the moisture has been removed in the recovery vessel 14a of the first stage is returned to the pipeline 2 downstream of the capturing device 4b of the second stage via the pipeline 18a. That is, by utilizing the pressure loss of the second-stage trapping device 4b itself, the position between the installation position of the first-stage trapping device 4a and the position where the pipe 18a serving as the gas flow returning means communicates with the pipe 2 is determined. A pressure difference occurs, and as a result, a suction action occurs in the capturing section of the capturing device 4a. Therefore, for example, in the case of three or more stages, the pipe 18 (n) as the gas flow returning means of the n-stage section is connected to the pipe 2 on the downstream side of the capturing device 4 (n + 1) of the next n + 1-stage section. Then, if the pipe 18 (final), which is the gas flow returning means of the final stage, is connected to the pipe 2 on the downstream side of the orifice 10, a predetermined suction action is generated in the capturing section of the capturing device in each stage.
[0016]
In the second embodiment, the pipe 18 (final) serving as a gas flow returning means at the final stage of the liquid membrane separator 20 for a multi-stage pipe is connected to the pipe 2 on the downstream side of the orifice 10. As shown in FIG. 3, the pipes 18a and 18b of the first and second stages of the multi-stage pipe type liquid film separator 20 'may be all connected to the pipe 2 downstream of the orifice 10. Further, as shown in FIG. 4, the pipes 18 a and 18 b of the first and second stages of the liquid membrane separator for multistage pipes 20 ″ are finally merged into one, and then downstream of the orifice 10. It may be connected to the pipe 2.
[0017]
Next, a third embodiment of the liquid membrane separator for piping according to the present invention will be described with reference to FIG. In the liquid film separation device 30 with guide suction shown in this figure, the capturing portion of the capturing device 32 has a double retracting structure. That is, an outer annular capturing portion 34 formed as an outer annular capturing portion for a liquid film formed annularly along the inner wall of the pipe 2, and a main gas flow formed annularly further inside the outer annular capturing portion 34. And an inner annular catching portion 36 functioning as an inner annular catching means. A pipe 38 functioning as a discharging means for discharging water from a part of the outer annular capturing portion 34 is connected thereto. On the other hand, a pipe 40 functioning as a return means for returning a gas flow from a part thereof is connected to the inner annular capturing section 36, and this pipe 40 is connected to the pipe 2 on the downstream side of the orifice 10. ing.
[0018]
The operation of the liquid film separation device with guide suction 30 configured as described above will be described. When the liquid film C moving downstream along the inner wall of the pipe 2 is pulled in only by the outer annular capturing portion 34, the liquid film C rides on the member defining the capturing portion 34, and the main gas flow A acts. Although the liquid film is scattered and the gas flow becomes unstable, a part of the main gas flow A located immediately above the liquid film is drawn into the inner annular trapping portion 36 by the double drawing structure, so that the gas flow becomes unstable. The liquid film C is stably drawn into the outer annular capturing portion 34 by the influence of the gas flow to be sucked. The liquid film C sucked by the outer annular capturing portion 34 is discharged to the outside via the pipe 38, and a part of the gas flow A sucked by the inner annular capturing portion 36 is returned to the pipe 2 via the pipe 40. Is done. Note that, in this embodiment, unlike the previous embodiment, no separating means is provided outside the pipe 2, so that the liquid droplets contained in the gas flow A must be surely removed in order to increase the liquid film removal efficiency. Since it is necessary to form a liquid film along the inner wall of the pipe 2, it is preferable to use a guide vane or a curved portion of the pipe.
[0019]
Finally, a fourth embodiment of the liquid membrane separator for piping according to the present invention will be described with reference to FIG. The liquid membrane separator 50 for piping is disposed in an outlet piping 54 of a blowdown heat recovery tank 52 connected to a steam generator (not shown) of the pressurized water reactor plant. The capturing device 4 is installed downstream of the curved portion of the outlet pipe. A pipe 16 for discharging water from a collection vessel 14 connected to the trapping device 4 via a pipe 12 is connected to a heat recovery tank 52, while a pipe 18 is connected to an outlet pipe 54 for returning steam. It is connected.
[0020]
The operation of the liquid membrane separator for piping 50 configured as described above will be described. The basic operation is the same as that of the first embodiment, but when the blowdown water BDW transferred from the steam generator flows into the heat recovery tank 52, the water flows down the tank inner wall by the cyclone separator method and Then, the steam containing water is transferred to the next place through the outlet pipe 54. At this time, the moisture contained in the steam inside the outlet pipe 54 passes through the curved portion and sticks along the inner wall by the action of the centrifugal force to form a liquid film. It is sucked. The sucked liquid film and vapor are collected in the collection container 14 via the pipe 12, where they are separated into water and vapor. The separated water is collected in the heat recovery tank 52, and the steam is returned to the outlet pipe 54.
[0021]
As described above, by separating and recovering the water from the steam containing the water in the outlet pipe 54 and returning the water to the heat recovery tank 52, the separation efficiency of water and steam in the heat recovery tank is increased as a result, Pressure pulsation in the outlet pipe can be prevented to stabilize the heat recovery tank and the pipe system.
[0022]
【The invention's effect】
A liquid membrane separation device for a pipe according to the present invention is provided with a capturing means annularly disposed on the inner periphery of a pipe for transferring a gas flow containing droplets, and is disposed downstream of the capturing means inside the pipe. A pressure difference is generated between the gas flow drawing-in position and the gas flow return position by connecting the pressure reducing means with the reduced pressure means in a piping system, and the gas flow including droplets is forcibly sucked in the capturing means by the pressure difference. As a result, the efficiency of removing the liquid film increases.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a first embodiment of a liquid membrane separator for piping according to the present invention.
FIG. 2 is a schematic view showing a second embodiment of the liquid membrane separation device for piping according to the present invention.
FIG. 3 is a schematic diagram showing a modification of the second embodiment shown in FIG.
FIG. 4 is a schematic diagram showing still another modification of the second embodiment shown in FIG. 2;
FIG. 5 is a schematic view showing a third embodiment of the liquid membrane separation device for piping according to the present invention.
FIG. 6 is a schematic diagram showing a fourth embodiment of the liquid membrane separation device for piping according to the present invention.
FIG. 7 is a schematic diagram showing an outline of a conventional liquid collecting device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pipe liquid membrane separation apparatus, 2 ... Pipe, 4 ... Capture device (capture means), 6 ... Circular part, 8 ... Capture part, 10 ... Orifice (decompression means), 12 ... Pipe, 14 ... Recovery container ( Separation / recovery means), 16: Pipe (discharge means), 18: Pipe (gas flow return means), 20, 20 ', 20''... Multistage pipe type liquid membrane separator, 30 ... Guide suction liquid membrane separator , 32: capturing device, 34: outer annular capturing portion (outer annular capturing device), 36: inner annular capturing portion (inner annular capturing device), 38, 40: piping, 50: liquid film separation device for piping, 52: blow Down heat recovery tank, 54 ... outlet pipe, 100 ... gas transfer pipe, 101 ... centrifugal force type separation member, 102 ... guide plate, 103 ... liquid collecting member, 104 ... discharge pipe, 105 ... trap.

Claims (9)

Capture means arranged annularly on the inner periphery of a pipe for transferring a gas flow containing droplets,
A pressure reducing means disposed downstream of the capturing means inside the pipe,
Discharging means for discharging droplets separated from the gas flow containing the droplets captured by the capturing means to the outside of the pipe,
A liquid film separation apparatus for piping, comprising: a gas flow returning means for returning a gas flow obtained by separating droplets from a gas flow containing the liquid droplets captured by the capturing means to a downstream side from the pressure reducing means. Furthermore, a separation / recovery for disposing a gas flow including the droplets, which is disposed outside the pipe and captured by the capturing unit, and separating the gas flow including the droplets into a droplet and a gas flow. 2. The liquid membrane separator for piping according to claim 1, further comprising means, wherein the discharge means and the vapor return means are connected to the separation and recovery means. The capturing means includes an outer annular capturing means for drawing in a liquid film composed of a collection of liquid droplets flowing downstream along the inner circumference of the pipe, and a gas flow existing on the inner circumferential side of the liquid film. 2. The liquid membrane separation device for piping according to claim 1, wherein the liquid film separation device has a double drawing structure with the inner annular capturing means. The pipe according to any one of claims 1 to 3, wherein the pipe is connected to a liquid recovery tank, and the liquid droplets discharged by the discharge unit are collected in the liquid recovery tank. Liquid membrane separation equipment. The liquid membrane separator for piping according to any one of claims 1 to 3, wherein the capturing means is provided in a plurality of stages in the piping. 6. The gas flow returning means corresponding to each stage other than the last stage is arranged so as to return the gas flow to the downstream side of the capturing unit of the next stage arranged further downstream. Liquid membrane separator for piping. The liquid membrane separator for piping according to any one of claims 1 to 6, wherein the pressure reducing means is an orifice. The liquid membrane separator for piping according to any one of claims 1 to 7, wherein the liquid membrane separator for piping is installed downstream of a curved portion in the piping. Withdrawing the gas flow containing the droplets along the inner wall of the pipe by capturing means arranged annularly on the inner periphery of the pipe for transferring the gas flow containing the droplets,
Separating the droplets from the gas stream containing the droplets drawn in by the trapping means and discharging the separated gas streams to the outside of the pipe, the gas flow from which the droplets are separated has a higher pressure downstream of the trapping means. Liquid membrane separation method for piping comprising returning to a lower position.

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