JP2015101344A - Chemical storage device and chemical processing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical storage device which avoids leakage risk during transportation of chemicals by a tank lorry, reduces transportation cost and purchase cost, makes the quality control of the chemicals easy, and to provide a chemical processing method using the chemical storage device.SOLUTION: A chemical storage device includes: a chemical tank 2 for storing a chemical; a ground tank (a tentative storage tank) 3 installed below the chemical tank in an area near the chemical tank 2; a carry-out duct 5 where one end opens at a bottom part of the chemical tank 2 and the other end is connected with the ground tank 3; a carry-out valve 8 which opens and closes the carry-out duct 5; a return duct 6 where one end opens at a bottom part of the ground tank 3 and the other end is connected with the chemical tank 2; and a feed pump 9 which is provided in the middle of the return duct 6 and pumps the chemical in the ground tank 3.

Description

  The present invention relates to a chemical storage device useful for temporarily transferring a chemical in the tank to the outside during inspection of a chemical tank containing a chemical such as concentrated sulfuric acid, and a chemical processing method using the chemical storage device About.

In the power plant, the steam after driving the power generation turbine is cooled to condensate, and this condensate is heated to become steam again, and this steam is used to drive the power generation turbine again. Since the circulating condensate is contaminated with various impurity ions and clads, a condensate demineralizer using an ion exchange resin is provided to remove these. Since sulfuric acid is usually used as a chemical for regenerating this ion exchange resin, a power plant equipped with a condensate demineralizer has a chemical tank for storing concentrated sulfuric acid.
When such a chemical tank is inspected, it is necessary to transfer the residual chemical in the tank to the outside of the tank of another power plant or the like, and a normal tank truck is used as the transfer means (see Patent Document 1). ).

Japanese Unexamined Patent Publication No. 07-198531

  However, when the residual chemical in the tank is transferred to the outside using a tank lorry, there is a risk that the chemical leaks during transportation. In addition, after receiving inspections, it is often the case that another tanker is arranged and accepted. In addition to the problem of chemical leakage during transportation, there is a cost for transporting and purchasing chemicals, and time is required for quality adjustment of chemicals. There is also the inconvenience of requiring.

  The present invention has been made in view of such circumstances, and avoids the risk of leakage at the time of transfer of the drug, reduces the transportation cost and the purchase cost, and can easily perform the quality control of the drug. The main object is to provide a storage device and a chemical treatment method using the storage device.

  In order to achieve the above object, a chemical storage apparatus according to the present invention includes a chemical tank that stores chemicals, a temporary storage tank that is installed near the chemical tank and below the chemical tank, and the chemical One end opened at the bottom of the tank, the other end connected to the temporary storage tank, an outlet valve for opening and closing the outlet conduit, and one end opened at the bottom of the temporary storage tank, The other end is provided with a return pipe line connected to the medicine tank, and a delivery pump provided in the middle of the return pipe to pump the medicine in the temporary storage tank.

  Therefore, when inspecting the chemical tank, in the tank blow process for transferring the residual chemical in the chemical tank out of the tank, the transfer valve is opened and the residual chemical in the chemical tank is temporarily stored via the transfer pipeline. In the chemical return process to return the chemical stored in the temporary storage tank to the chemical tank, the transfer valve is closed and the delivery pump is operated to temporarily store the chemical tank. It is possible to return the chemical in the tank to the chemical tank via the return pipe.

  For this reason, it is possible to move the chemical in the chemical tank out of the tank without using a tank lorry, and there is no need to transport it using the tank lorry. It is possible to reduce transportation costs and purchase costs. In addition, since the chemical transferred near the chemical tank can be stored, the quality control of the chemical can be sufficiently performed.

  Further, on the premise of the configuration described above, one end of the return line is connected to the downstream side of the delivery pump, and the other end is connected to a chemical supply line that supplies the chemical in the chemical tank to the supply system. You may make it further comprise a channel | path and the communication valve which opens and closes the said communication pipe line.

In such a configuration, a pump or the like provided for supplying the chemical in the chemical tank to the supply system breaks down, and it is difficult or insufficient to supply the chemical from the chemical tank to the chemical supply system. In this case, by opening the transfer valve and opening the communication valve and operating the delivery pump, the chemical in the chemical tank is temporarily transferred to the temporary storage tank, and the chemical transferred to the temporary storage tank is transferred to the temporary storage tank. It is possible to supply from the communication line to the chemical supply line.
As the temporary storage tank, an underground tank buried underground may be used.

  As described above, according to the present invention, the temporary storage tank installed below the chemical tank is provided in the vicinity of the chemical tank, and the bottom of the chemical tank and the temporary storage tank are opened and closed by the transfer valve. In addition, the bottom of the temporary storage tank and the chemical tank are connected by a return pipe with a delivery pump provided in the middle. It is possible to transfer the chemical in the temporary storage tank to the chemical tank after the inspection of the chemical tank is completed, and the chemical in the temporary storage tank can be transferred to the chemical tank. It becomes possible to transport chemicals. For this reason, it becomes possible to reduce the conveyance cost and purchase cost of a chemical | medical agent. In addition, since it is possible to store in the vicinity of the chemical tank, the quality control of the chemical can be sufficiently performed.

  In addition, since the chemical supply line that supplies the chemical in the chemical tank to the supply system is connected to the return pipe by a communication line that is opened and closed by a communication valve, the chemical in the chemical tank is connected to the supply system. Even if the pump provided for supply breaks down and it becomes difficult or insufficient to supply the chemical from the chemical tank to the chemical supply system, the chemical is supplied from the delivery pump through the temporary storage tank. It becomes possible to supply to a chemical supply system, and it can be used as a backup for a normal chemical supply system, and a stable chemical supply can be ensured.

Fig.1 (a) is a whole block diagram which shows the chemical | medical agent storage apparatus based on this invention, FIG.1 (b) is a table | surface which shows the operation state of a valve and a pump. FIG. 2 is a flowchart showing an operation example of tank blow processing by the control unit. FIG. 3 is a flowchart showing an operation example of the medicine return process by the control unit. FIG. 4 is a flowchart showing an operation example of emergency processing by the control unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, an apparatus for storing concentrated sulfuric acid used in a condensate demineralizer is shown as the chemical storage apparatus 1. The chemical storage device 1 includes a chemical tank 2 for storing concentrated sulfuric acid to be supplied to a sulfuric acid dilution tank connected to an ion exchange resin regeneration tower (not shown), and a lower side of the chemical tank 2 in the vicinity of the chemical tank 2. An underground tank (temporary storage tank) 3 buried underground, and a chemical supply line 4 having one end opened at the bottom of the chemical tank 2 and the other end connected to a chemical supply system such as a sulfuric acid dilution tank One end is opened at the bottom of the chemical tank 2, the other end is connected to the top of the underground tank 3, and one end is opened at the bottom of the underground tank 3, and the other end is located at the top of the chemical tank 2. And a return line 6 connected thereto.

  The chemical supply pipe 4 is provided with a chemical supply pump 7. By operating the chemical supply pump 7, concentrated sulfuric acid in the chemical tank 2 is pumped to the chemical supply system via the chemical supply line 4. Yes. Further, an outlet valve 8 is provided in the middle of the outlet pipe 5, and the outlet pipe 5 is controlled to be opened and closed by operating the outlet valve 8.

  In the middle of the return pipe 6, a delivery pump 9 for pumping chemicals in the underground tank 3 and a return valve 10 arranged downstream thereof are provided. By operating the delivery pump 9, Concentrated sulfuric acid is sent to the downstream side via the return line 6, and the return line 6 is controlled to open and close by operating the return valve 10.

  Moreover, one end is connected between the delivery pump 9 and the return valve 10 of the return line 6, and the other end is connected to the drug supply line 4, and a communication line 11 that leads to the drug supply system is provided. A communication valve 12 is provided in the middle of the communication pipe 11, and the communication pipe 11 is controlled to be opened and closed by operating the communication valve 12.

  Each of the chemical tank 2 and the underground tank 3 is provided with liquid level sensors 21 and 22 for detecting the remaining amount of concentrated sulfuric acid in the tank, and the detection signals of these liquid level sensors 21 and 22 are input to the control unit 20. It has come to be. The control unit 20 is connected to an operation panel 23 for selecting various operation modes. Based on signals from the liquid level sensors 21 and 22, the control unit 20 opens and closes each valve so as to obtain the operation mode selected on the operation panel 23. And the operation / stop of each pump is controlled.

  The control unit 20 opens / closes each valve and operates / stops each pump in each operation mode as shown in FIG. 1B, and supplies concentrated sulfuric acid in the chemical tank 2. During the normal operation of supplying the gas, the transfer valve 8 is closed, the return valve 10 is closed, the communication valve 12 is closed, the delivery pump 9 is stopped, and only the chemical supply pump 7 is operated.

  When the residual concentrated sulfuric acid in the tank is temporarily transferred to check the chemical tank 2 from such a state, the tank blow processing mode is selected by the operation panel 23. This tank blow process is performed as shown in FIG. 2. The transfer valve 8 is opened, the return valve 10 is closed, the communication valve 12 is closed, the delivery pump 9 is stopped, and the chemical supply pump 7 is closed. Is stopped (step 50). As a result, the remaining concentrated sulfuric acid in the chemical tank 2 is transferred to the underground tank 3 via the transfer conduit 5 by being left to gravity.

  The control unit 20 monitors the remaining amount of concentrated sulfuric acid in the chemical tank 2 based on the detection signal from the liquid level sensor 21 provided in the chemical tank 2 (step 52), and the residual concentrated sulfuric acid in the chemical tank. When it is determined that there is no more, notification of the completion of the transfer is performed, for example, by lighting a predetermined part of the operation panel 23 (step 54).

  When the inspection of the chemical tank 2 is completed and the concentrated sulfuric acid temporarily stored in the underground tank 3 is returned to the chemical tank 2, the chemical return processing mode is selected by the operation panel 23. This medicine return process is performed as shown in FIG. 3. The transfer valve 8 is closed, the return valve 10 is opened, the communication valve 12 is closed, the delivery pump 9 is operated, and the medicine supply pump 7 is operated. Is in a stopped state (step 60). As a result, the concentrated sulfuric acid stored in the underground tank 3 is sucked up by the delivery pump 9 and returned to the chemical tank 2 through the return pipe 6.

  The control unit 20 monitors the remaining amount of concentrated sulfuric acid in the underground tank 3 based on the detection signal from the liquid level sensor 22 provided in the underground tank 3 (step 62), and the remaining concentrated sulfuric acid in the underground tank. When it is determined that there is no more, the delivery pump 9 is stopped, and a return completion notification is made by, for example, lighting a predetermined part of the operation panel 23.

  Therefore, at the time of inspection of the chemical tank 2, the residual concentrated sulfuric acid in the chemical tank 2 is temporarily transferred to the underground tank 3 via the transfer pipe 5, and after the inspection of the chemical tank 2 is completed, it is sent out. By operating the pump 9, it is possible to return the concentrated sulfuric acid in the underground tank 3 to the chemical tank 2 through the return pipe 6, so that there is no need to use a tank truck as in the prior art. The chemical can be temporarily transferred to the outside of the tank, and it is not necessary to transport the chemical with a tank truck. Therefore, the transportation cost can be reduced, and the leakage of concentrated sulfuric acid that occurs during transportation can be eliminated. Furthermore, since the concentrated sulfuric acid can be stored in the vicinity of the chemical tank 2 at the time of tank inspection, the chemical quality control can be sufficiently performed. After the tank inspection, the concentrated sulfuric acid is removed from the underground tank 3 by chemical tank. Since it returns to 2, it becomes possible to hold down the purchase cost of a chemical | medical agent.

  By the way, when the chemical supply pump 7 breaks down or a problem occurs in the chemical tank 2, it may be difficult or insufficient for the chemical supply pump 7 to supply chemicals on the normal route. In such a case, the emergency processing mode is selected by the operation panel 23. This emergency process is performed as shown in FIG. 4. The transfer valve 8 is opened, the return valve 10 is closed, the communication valve 12 is opened, the delivery pump 9 is operated, and the chemical supply pump 7 is operated. Is in a stopped state (step 70). As a result, concentrated sulfuric acid in the chemical tank 2 is transferred to the underground tank 3 through the transfer pipe 5 in accordance with gravity, and the concentrated sulfuric acid transferred to the underground tank 3 is sucked up by the delivery pump 9 and returned. It is pumped from the pipeline 6 to the chemical supply pipeline 4 via the communication pipeline 11 and supplied as it is to the chemical supply system.

  Even in such an operation, the control unit 20 monitors the remaining amount of concentrated sulfuric acid in the underground tank 3 based on the detection signal from the liquid level sensor 22 provided in the underground tank 3 (step 72). When it is determined that there is no remaining concentrated sulfuric acid in the underground tank, the delivery pump 9 is stopped, and a notification of insufficient sulfuric acid remaining in the underground tank 3 is given, for example, at a predetermined position on the operation panel 23. (Step 74).

  Therefore, even when it is difficult or insufficient to supply chemicals from the chemical tank 2 to the chemical supply system via the chemical supply pump 7, concentrated sulfuric acid is supplied from the delivery pump 9 to the chemical supply system via the underground tank 3. Therefore, a supply route for backup of concentrated sulfuric acid can be formed, and supply of concentrated sulfuric acid to the chemical supply system can be stabilized.

  In the above-described example, the example of the underground tank 3 is shown as a temporary storage tank. However, a similar configuration can be adopted as long as the tank is located below the chemical tank 2. Moreover, although concentrated sulfuric acid was illustrated as a chemical | medical agent, you may make it store and process not only concentrated sulfuric acid but various chemicals similarly using the same storage apparatus.

DESCRIPTION OF SYMBOLS 1 Chemical storage device 2 Chemical tank 3 Underground tank 4 Chemical supply line 5 Outlet line 6 Return line 7 Chemical supply pump 8 Outlet valve 9 Outlet pump 10 Return valve 11 Connection line 12 Communication valve 20 Control unit

Claims (5)

A chemical tank for storing chemicals;
A temporary storage tank installed near the chemical tank and below the chemical tank;
One outlet opening at the bottom of the chemical tank and the other end connected to the temporary storage tank,
An exit valve for opening and closing the exit conduit;
A return line having one end opened at the bottom of the temporary storage tank and the other end connected to the chemical tank;
A delivery pump that is provided in the middle of the return conduit and pumps the chemical in the temporary storage tank;
The chemical | medical agent storage apparatus characterized by comprising. One end is connected to the downstream side of the return pump of the return line, and the other end is connected to a chemical supply line for supplying the chemical in the chemical tank to a supply system,
A communication valve for opening and closing the communication line;
The medicine storage device according to claim 1, further comprising:   The chemical storage device according to claim 1 or 2, wherein the temporary storage tank is an underground tank buried underground. A chemical treatment method using the chemical storage device according to any one of claims 1 to 3,
In the tank blow process for temporarily transferring the chemical in the chemical tank to the outside, the transfer valve is opened, and the chemical in the chemical tank is transferred to the temporary storage tank via the transfer pipeline,
In the return processing for returning the medicine stored in the temporary storage tank to the medicine tank, the delivery valve is closed and the delivery pump is operated. A chemical treatment method using the chemical storage device according to claim 2,
When the supply of chemicals from the chemical tank to the chemical supply system is difficult or insufficient, the delivery valve is opened, the communication valve is opened, and the delivery pump is operated. Processing method.

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