JP3727042B2 - Precoat type filtration desalination equipment with pressure relief mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a precoat filtration device, and in particular, a precoat filtration desalination having a pressure relief mechanism that prevents a pressure increase during operation of a holding pump for treating condensate, reactor water, and fuel pool water in a nuclear power plant or the like. Relates to the device.
[0002]
[Prior art]
A known precoat type condensate demineralizer will be described with reference to FIG.
While the demineralizer is processing the condensate, the precoat layer is held by the pressure at which the condensate passes through the precoat layer 2, but the condensate is not processed and is waiting for the next sampling. In the “standby step”, since there is no flow, the holding pump 11 is operated to apply pressure to the precoat layer 2 to prevent the precoat layer 2 from falling off.
In a “standby process” where normal power plants are in operation and are drained by backwashing when replacing the used precoat layer 2 and re-precoating and waiting for the next sampling, pressure is applied to the condensate inlet header 5. Therefore, even when the holding pump 11 is in operation, even if the condensate inlet valve 6 of the condensate filtration demineralization tower 1 is opened, water in the tower is not drawn out. Even if the pressure rises due to Joule heat of the holding pump 11, the pressure does not increase beyond the pressure of the inlet header 5 because the inlet side valve 6 is open.
[0003]
However, at the time of initial plant start-up or plant start-up at each periodic inspection, pre-coating is often performed in a state where water does not flow into the condensate inlet header 5, and a state of waiting for water to flow into the condensate header 5 occurs. . In this case, since the holding pump 11 is operated with the condensate inlet side valve 6 and the outlet side valve 9 being completely closed in order to prevent drainage of the condensate filtration demineralization tower 1, it is sealed by pump Joule heat. The pressure in the system will rise excessively, causing damage to equipment and water leakage.
Conventionally, in order to release this excessive pressure, the pressure gauge 21 provided in the operating system 12 of the pressure holding device is viewed, and if the pressure increases, it is excessively caused by the drain valve 23 provided in the drain drainage system 22 of the pump 11. Pressure was released manually. In this method, while the inlet valve 6 and the outlet valve 9 continue to be closed, it is necessary to monitor the pressure increase every certain period regardless of day and night, and perform pressure relief, and the labor is excessive. .
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a precoat filtration desalination apparatus having a pressure relief mechanism that can perform pressure relief smoothly and safely with a simple device, not manually, in view of the above-described conventional technology. And
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the present invention, in a precoat type filtration demineralization tower of a type in which raw water is introduced from the lower part and treated water is extracted from the upper part, a pressure having an on-off valve drawn from the bottom of the filtration demineralization tower. A dewatering line is provided, and the depressurization line has a structure having an opening to the atmosphere at a position higher than the top of the demineralization tower. is there.
In the desalination apparatus, the pressure release line may be provided with a pipe or container having a large diameter before the opening to the atmosphere at a position higher than the top of the desalting tower.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In general, the pre-coating condensate filtration and desalination equipment is characterized by the equipment layout because the pre-coat layer is extremely difficult to mix air, so the tower is placed at the top as shown in FIG. In many cases, it is arranged to discharge from the tower.
Moreover, since the chamber in which the tower is installed is surrounded by a wall, it is impossible to place a valve, and a structure in which a valve and a piping chamber are provided in the lower layer is adopted.
In this apparatus structure, the simplest method of releasing the pressure is to open the valve 25 connected to the pipe 24, so that the pressure can be released and the excess water escapes and the water rises as the pressure rises. Thus, when the valve is closed when switching from the “standby process” to the “water sampling process” for treating water, air is introduced into the pipe 24 from the valve 25 to the top of the tower 1. Remains.
[0007]
Since air is a compressible gas, when the inlet valve 6 is opened and the inside of the tower is pressurized, water is temporarily passed from the primary side 3 of the tower 1 through the precoat layer to the secondary side 4 at a high flow rate. If the pre-coat layer and the amount of residual air are large, the apparatus itself may be adversely affected and this method cannot be employed.
In the method of extracting from the primary side 3 of the tower 1, that is, when extracting the valve 27 from the pipe 26, there is little adverse effect due to pressure fluctuation of the valve opening / closing, but if the valve is opened during the precoat holding period, Therefore, it is necessary to provide a sealed valve and a safety valve that controls the pressure or an automatic valve that opens and closes by a pressure signal. However, since such equipment is provided at the bottom of the tower, foreign matter (iron rust, etc.) may be mixed in and pre-coating material may be mixed in, and there is concern about the reliability of the instrument.
[0008]
The present invention has been made as a result of these studies, and has a pressure relief mechanism in which a pressure relief is provided at the bottom of the tower to eliminate the influence of residual air and no special instruments are used. is there.
Hereinafter, the present invention will be described with reference to the drawings.
In FIG. 1, the schematic block diagram of an example of the precoat type filtration desalination apparatus which has a pressure release mechanism of this invention is shown.
In FIG. 1, 1 is a precoat type filtration desalting tower, 2 is a precoat layer, 3 is a primary side, 4 is a secondary side, 5 is an inlet header, 6 is an inlet valve, 7 is an inlet pipe, 8 is an outlet header, 9 Are an outlet valve, 10 is a discharge pipe, 11 is a holding pump, 12 is a pressure holding pipe, 13 is a pressure relief line, 14 is an on-off valve, and 15 is an opening.
[0009]
Thus, in the present invention, the depressurization line 13 has the opening 15 at a position higher than the top of the demineralization tower 1.
And, when the holding pump 11 is operated in the state where the inlet valve 6 and the outlet valve 9 are completely closed, such as when the plant is started up, the on-off valve 14 of the pressure release line 13 is opened. To maintain the precoat, the pressure in the closed system consisting of the holding pump 11 of the pressure holding line from the primary side 3 of the pipe 12-pipe 7-tower 1 3-secondary side 4-pipe 10-pipe 12 of tower 1 If it rises excessively, excess water will be discharged from the depressurization line 13 through the opening 15 and maintained at a constant pressure.
As described above, according to the present invention, an excessive pressure can be automatically extracted by providing a pressure relief mechanism having a simple structure without providing a special device. Further, there is no concern that air remains in the pressure release pipe 13.
[0010]
FIG. 2 and FIG. 3 show schematic configuration diagrams of an apparatus having a pressure release mechanism of the desalination apparatus of the present invention.
In FIG. 2, the pressure release line 13 is connected to the bottom of the pipe 16 with the horizontal pipe portion higher than the top of the tower 1 as a pipe 16 having a large diameter, and passes through the connecting pipe 17 from the top of the pipe 16. It is connected to the opening 15. Further, a pipe (siphon cutting) 19 for preventing drainage by the siphon is connected from the top of the pipe 16.
In FIG. 3, a container 18 is installed in the pressure release line 13 in place of the large-diameter pipe 16 in FIG. 2, and is connected from the upper part of the container 18 to the open port 15 through the connection pipe 17. . Further, a siphon cutter 19 is connected to the top of the container 18.
[0011]
By adopting the configuration as shown in FIGS. 2 and 3, it is possible to always maintain a constant pressure against fluctuations in the internal pressure due to the outside air temperature or the like. That is, the water held in the large-diameter pipe 16 and the container 18 serves as an adjustment mechanism for holding the pressure when the pressure on the primary side 3 of the tower 1 decreases.
In addition, although all this invention demonstrated by the precoat type filtration desalination apparatus, it is not limited to this, It can apply to a precoat type filtration apparatus generally.
[0012]
【The invention's effect】
According to the present invention, the simple pressure release mechanism as described above enables the pressure due to the pump joule heat to be automatically maintained constant even when the precoat holding operation for holding the precoat is continuously performed. , Troubles due to excessive pressure can be avoided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a desalination apparatus having a pressure release mechanism according to the present invention.
FIG. 2 is a schematic configuration diagram of a desalting apparatus having another pressure release mechanism of the present invention.
FIG. 3 is a schematic configuration diagram of a desalting apparatus having another pressure release mechanism of the present invention.
FIG. 4 is a schematic configuration diagram of a conventional precoat type condensate filtration desalination apparatus.
[Explanation of symbols]
1: precoat type filtration desalting tower, 2: precoat layer, 3: primary side, 4: secondary side, 5: inlet header, 6: inlet valve, 7: inlet pipe, 8: outlet header, 9: outlet valve, 10: discharge pipe, 11: holding pump, 12: pressure holding pipe, 13: pressure release line, 14: on-off valve, 15: open port, 16: large-diameter pipe, 17: connecting pipe, 18: container, 19: siphon Cut,

Claims (2)

In the precoat type filtration desalination tower in which raw water is introduced from the lower part and the treated water is withdrawn from the upper part, a depressurization line having an opening / closing valve is provided to be drawn from the bottom of the demineralization tower, A precoat type filtration desalination apparatus having a pressure relief mechanism, characterized by having an opening to the atmosphere at a position higher than the top of the tower. 2. The precoat having a pressure relief mechanism according to claim 1, wherein the pressure relief line is provided with a pipe or container having a large diameter in front of an opening to the atmosphere at a position higher than the top of the demineralization tower. Type filtration desalination equipment.

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