JPH0884903A - Method and apparatus for supplying raw liquid to pressure dewaterer - Google Patents

Abstract

PURPOSE: To provide a method and an apparatus for supplying raw liquid to a pressure dewaterer in which the number of pressure tanks is reduced from three to two and maintenance labor is minimized without causing the deterioration of performance. CONSTITUTION: First, raw liquid is fed to an upper pressure tank l, a lower pressure tank 2, and a pressure dewaterer 30, which are arranged in series, by a low pressure pump 5, and the pump is stopped temporarily. Next, the pressurized raw liquid in the tank is fed continuously to the pressure dewaterer while the upper pressure tank being pressurized by an air compressor 6, and when the tank becomes vacant, a communication valve 3 between the tanks 1, 2 is closed, and the lower tank is pressurized to supply the pressurized raw liquid continuously to the pressure dewaterer. At the same time, the raw liquid is supplied to the upper pressure tank by a pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a stock solution supply to a pressure dehydrator, which is suitable for the purpose of continuously feeding a stock solution such as slurry to a filter press without using a slurry pump or a diaphragm pump. A method and a supply device.

[0002]

2. Description of the Related Art Conventionally, a slurry pump or a diaphragm pump has conventionally been used as a means for pumping sludge when a sludge-like stock solution is applied to a filter press for dehydration. These pumps become more expensive as the discharge pressure and the discharge amount are increased in order to enhance the dehydration ability. In addition, the wear of the pump becomes severe, resulting in a significant increase in maintenance cost. Therefore, an improved method using both a slurry pump and air pressure was considered. For example, “Japanese Patent Publication No. 62-41
The techniques disclosed in Japanese Patent Application No. 048 ”and Japanese Patent Application Laid-Open No. 59-69” are examples thereof.

[0003]

However, as long as the slurry pump is used, the above-mentioned major drawbacks cannot be eliminated. Therefore, the applicant of the present application has previously created a method and apparatus for continuously supplying a pressurized stock solution to a pressure dehydrator without using a slurry pump and only by air pressure, and has already applied for a patent. The outline of the present invention is to supply the undiluted solution, which is made to flow down from the undiluted solution tank in the high position to the service tank (pressure tank) in the middle position, to two pressure tanks arranged in parallel in the low position. The undiluted solution inside is alternately supplied to the pressure dehydrator by air pressure, and the undiluted one pressure tank is replenished with undiluted solution from the service tank during this period. The object of the present invention is to further improve the invention of the prior application, reduce the number of three pressure tanks to two, and replenish the stock solution to the service tank for low pressure, which is far more advantageous in terms of price and maintenance cost. By using the pump of
It is an object of the present invention to provide a method and an apparatus for supplying a stock solution to a pressure dehydrator, in which the structure of the entire apparatus is simplified and maintenance work can be minimized.

[0004]

In order to achieve the above object, a method for supplying a stock solution to a pressure dehydrator according to the present invention comprises an upper pressure tank and a lower pressure tank which can communicate with each other through a communication valve. A method of using a stock solution supply device comprising a tank, a low-pressure pump for supplying the stock solution to these tanks, and an air compressor for pressurizing the stock solution in both tanks and supplying it to a pressure dehydrator. , Actuating the pump to supply the undiluted solution to the upper pressure tank, the lower pressure tank and the pressure dehydrator which are connected in series in tandem, stop the pump, and then pressurize the upper pressure tank. To continuously supply the pressurized stock solution in the tank to the pressure dehydrator, and then close the communication valve to pressurize the lower pressurization tank to continuously pressurize the stock solution in the tank to the pressure dehydrator. Supply and at the same time pump After replenishing the stock solution in the upper pressurizing tank and making the pressure in both the upper and lower pressurizing tanks the same, open the communication valve to return the stock solution to the pressure dehydrator to the initial state. Adopted. The stock solution supply device according to the present invention comprises an upper pressurization tank 1 and a lower pressurization tank 2 which can communicate with each other via a communication valve 3, and a low-pressure pump for supplying the stock solution to the upper pressurization tank 1. 5, and an air compressor 6 for alternately pressurizing the undiluted solution in the upper pressure tank 1 and the lower pressure tank 2 to pressure-feed the dehydrator,
Operation and stop of the pump 5 and the air compressor 6,
The control unit 20 is configured to open and close valves such as the communication valve 3 according to a predetermined program. Then, inside the upper pressure tank 1 and the lower pressure tank,
It is advisable to enable conduction by means of a conduction pipe 12 with a valve 12v interposed.

[0005]

In order to continuously supply the pressurized stock solution to the pressure dehydrator by the method and apparatus of the present invention, first, the stock solution is tandemly formed by the low pressure pump 5 with the communication valve 3 opened. After feeding into the connected upper pressure tank 1, lower pressure tank 2 and pressure dehydrator, the pump 5 is stopped. Next, the stock solution in the upper pressure tank 1 is mixed with the air compressor 6
It is pressurized with compressed air supplied from and is then fed to a pressure dehydrator. When the stock solution in the upper pressurizing tank 1 has decreased, the communication valve 3 is closed, and the stock solution in the lower pressurizing tank 2 is pressurized with compressed air and subsequently sent to the press dehydrator. At the same time, the stock solution is replenished to the upper pressurizing tank 1 by the pump 5, and the valve 12v provided in the communication pipe 12 is once opened to make the internal pressures of the upper and lower pressurizing tanks 1 and 2 the same. The universal valve 3 can be closed smoothly.
The device is thus returned to the initial state of stock solution feed to the pressure dehydrator.

[0006]

EXAMPLES The present invention will be described below with reference to the drawings, regarding an example in which the present invention is applied to the case where a sludge-like stock solution is dehydrated using a filter press (pressurized dehydrator).
The undiluted solution supply device shown in FIG. 1 connects an upper pressure tank 1, a lower pressure tank 2 arranged immediately below the upper pressure tank 1, a bottom portion of the upper pressure tank 1 and a top portion of the lower pressure tank 2 to each other. A communication pipe 4 with a universal valve 3 interposed therebetween, a pump 5 for supplying the stock solution to the upper pressure tank 1 at a low pressure, and both upper and lower pressure tanks 1.
Air compressor 6 that alternately supplies compressed air to 2
And are the main components. As the communication valve 3 of this embodiment, an automatically operated valve with an actuator (ball valve) is used.

A stock solution pipe 7 extending from a pump 5 is connected to a stock solution inlet 1a provided on a lower side wall of the upper pressure tank 1. An air pipe 1 extending from the air compressor 6 is connected to the air inlet 1b provided at the top of the upper pressure tank 1. Further, a communication port 1c is provided at the top of the upper pressure tank 1.

On the other hand, a stock solution outlet 2a is provided in the lower portion of the lower pressure tank 2. Further, an air inlet 2b and a conduction port 2c are provided at the top. An end of an air branch pipe 9 branched from the air pipe 8 is connected to the air inlet 2b. Valves (electromagnetic valves) 8v and 9v are interposed in the air pipe 8 and the air branch pipe 9, respectively. A liquid supply pipe 10 connected to the filter press 30 is connected to the stock solution outlet 2a. A manual valve 10v and a drain cock 11 are interposed in the liquid supply pipe 10.

Further, a communication port 1c of the upper pressure tank 1,
The lower pressure tank 2 is connected to the conduction port 2c by a conduction pipe 12. A valve 12v is interposed in the conduction pipe 12, and an exhaust pipe 13 for exhausting the inside of the upper pressure tank 1 is branched between the valve 12v and the conduction port 1c. 13v is an exhaust valve. These valves are also solenoid valves. A liquid level upper limit sensor 14 and a liquid level lower limit sensor 15 are installed in the upper pressure tank 1. By installing the liquid level lower limit sensor 15 also in the lower pressurizing tank 2, it is possible to help prevent air from entering the filter press 30.

Reference numeral 20 denotes a control unit of the stock solution supply device, which starts / stops or opens / closes the pump 5, the air compressor 6, the communication valve 3, and the valves 8v, 9v, 12v, 13v (electromagnetic valves) according to a predetermined program. Let

Next, the operation of the stock solution supply device will be described. When the apparatus is on standby, the communication valve 3 and the valve 10v provided in the pipe of the stock solution supply system are open. or,
The valves 8v and 9v provided in the pipe of the air supply system and the valve 12v of the conduction pipe 12 are both closed.

When the apparatus is started in this state, the pump 5
Is started, and the undiluted solution supplied from a storage tank (not shown) is sequentially sent to the upper pressurization tank 1, the lower pressurization tank 2 and the filter press 30 which are connected in a tandem via a pipe. Then, the pump 5 is stopped after the feeding is completed.

When the pump 5 is stopped, the valve 8v is opened and the compressed air having a predetermined pressure stored in the air compressor 6 in advance is supplied to the upper space of the upper pressure tank 1. Therefore, the undiluted solution in the tank pressurized to a predetermined pressure
It is continuously supplied to the filter press 30.

When the liquid level in the upper pressurizing tank 1 gradually lowers and reaches the position of the liquid level lower limit sensor 15, the communication valve 3 and the valve 8v are closed and the valve 9v is opened. Along with this, compressed air having a predetermined pressure is supplied to the lower pressurizing tank 2, so that the stock solution pressurized to a predetermined pressure is continuously supplied to the filter press 30.

At the same time, the exhaust valve 13v is opened, and the pump 5 is restarted to replenish the stock solution to the empty upper pressurizing tank 1. When the liquid level reaches the position of the liquid level upper limit sensor 14, the pump 5 is stopped and the exhaust valve 13v is closed.

After that, the valve 8v is opened to increase the internal pressure of the upper pressurizing tank 1, and both the valves 8v and 9v are closed. In this state, the valve 12 interposed in the conduction pipe 12
Once v is opened, the upper pressure tank 1 and the lower pressure tank 2
I will make the internal pressure of the same. As a result, the communication valve 3 can be released smoothly. Then, by opening the valve 8v, the pressurized stock solution is continuously supplied to the filter press 30. Thus, the apparatus returns to the state at the time of starting the undiluted solution supply, completes one cycle of the apparatus operation, and shifts to the next operation cycle.

After that, by repeating this operation cycle repeatedly, the pressurized stock solution with almost no pressure fluctuation is continuously supplied to the filter press 30.

[0018]

As is apparent from the above description, according to the method and the apparatus for supplying the stock solution to the pressure dehydrator of the present invention, various excellent effects as listed below can be obtained. (A) It is not necessary to use a high-pressure slurry pump or diaphragm pump, which is expensive and requires a high maintenance cost, even if the stock solution is sludge or the like. (B) Therefore, the cost required for pressure dehydration of the stock solution can be significantly reduced. (C) Continuously pressurizing the pressurized stock solution with almost no pressure fluctuation by skillfully using the low pressure pump for replenishing the stock solution to the pressurized tank and the compressed air for feeding the stock solution. You can continue to feed the dehydrator. (D) Therefore, when the pressure dehydrator is a filter press, the pulsation of the liquid pressure exerted on the press plate does not cause a problem that the thickness and composition of the press cake become uneven, and the dehydration efficiency is sufficient. Be raised to. (E) Prior to the opening / closing operation of the communication valve connecting the upper pressurization tank and the lower pressurization tank, using a conduction pipe,
If the internal pressures of these two tanks are the same, the communication valve can be opened and closed smoothly and reasonably, and the damage can also be prevented. (F) In the invention of the prior application, three pressurization tanks are needed, and two pressurization tanks are sufficient. Therefore, the structure of the entire apparatus can be simplified and the maintenance cost can be reduced. (G) The pressurizing stock solution can be continuously supplied to the pressurizing dehydrator with the pressurizing tank having a relatively small volume, and the two pressurizing tanks are arranged on the upper and lower sides, so that the installation space required for the apparatus can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of an entire stock solution feeder showing an embodiment of the present invention.

[Explanation of symbols]

 1 Upper Pressure Tank 1a Undiluted Liquid Inlet 1b Air Inlet 1c Conducting Port 2 Lower Pressurizing Tank 2a Undiluted Liquid Outlet 2b Air Inlet 2c Inlet Port 3 Communication Valve 4 Communication Pipe 5 Pump 6 Air Compressor 7 Undiluted Liquid Pipe 8 Air Pipe 9 Air Branch Pipe 8a, 9a Valve 10 Liquid supply pipe 10v Valve 11 Drain cock 12 Conduction pipe 13 Exhaust pipe 12v, 13v Valve 14 Liquid level upper limit sensor 15 Liquid level lower limit sensor 20 Control unit 30 Filter press (pressurizing dehydrator)

Claims (3)

[Claims] 1. An upper pressure tank and a lower pressure tank which can communicate with each other through a communication valve, a low-pressure pump for supplying a stock solution to both tanks, and a pressurizing and pressurizing stock solution in both tanks. A method of using a stock solution supply device provided with an air compressor for supplying to a pressure dehydrator, comprising first operating a pump to sequentially connect an upper pressure tank, a lower pressure tank and a pressure dehydrator. Then, the pump is stopped, and then the pressurized stock solution in the upper pressurizing tank is continuously supplied to the pressurizing dehydrator, and then the communication valve is closed and Pressurize the pressurized tank to continuously supply the pressurized stock solution in the tank to the pressure dehydrator, and at the same time, replenish the stock solution in the upper pressurized tank by the pump, and After making the inside pressure the same, communicate Method of supplying stock to the pressurized dewatering machine, characterized in that by opening the valve was set to return to the initial state of the solution feed to the pressurized dewatering machine. 2. An upper pressure tank 1 and a lower pressure tank 2 which can communicate with each other via a communication valve 3, a low pressure pump 5 for supplying a stock solution to the upper pressure tank 1, and the upper pressure tank. An air compressor 6 for alternately pressurizing the stock solution in the pressure tank 1 and the lower pressurizing tank 2 to send it under pressure to a pressure dehydrator, and operating and stopping the pump 5 and the air compressor 6.
A stock solution supply device for a pressurized dehydrator, comprising: a control unit 20 for opening and closing valves such as the communication valve 3 according to a predetermined program. 3. A conducting pipe 12 having a valve 12v in the inside of the upper pressure tank 1 and the lower pressure tank 2.
The stock solution supply device to the pressure dehydrator according to claim 2, wherein the stock solution is made conductive by means of a.