JPH0133126Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a filter press with a diaphragm compression stopper, and in particular, an economical pressurized water for extracting pressurized water in a pressurized chamber formed between a filter plate and a diaphragm after the pressing process. Regarding the return device.

The operating cycle of this kind of filter press is
It consists of a frame closing process, mud feeding process, squeezing process, drying process, opening/discharging process, and filter cloth washing process. The operations for these series of steps are controlled by a sequence or the like so that they proceed continuously and efficiently. For this reason, it is important to properly manage the supply of undiluted liquid and pressurized water, as well as to return excess undiluted liquid and to quickly remove the pressurized water in the pressurized chamber formed between the filter plate and diaphragm after squeezing. As a result, it has become an important factor to reduce the pressure in the filter chamber, open it, and perform the additional operations to return the pressurized water completely and promptly in order to shorten the cycle time of the filter press. There is.

Conventionally, pressurized water is returned by supplying compressed air into a pressurizing chamber, discharging the pressurized water in the pressurizing chamber, and then sucking the remaining water in the pressurizing chamber using the mechanical force of a vacuum pump to return it to the outside. It is forcibly discharged. However, this type of pressure water discharge work requires a dedicated vacuum pump, attached branch piping, seal water piping for the vacuum pump, etc., which not only increases equipment costs but also causes noise from the movement of the vacuum pump. In large part, sequence control is complicated because it requires control for operating the vacuum pump and switching pipes during sequence control.

It is therefore an object of the present invention to provide a system for returning pressurized water that can be operated smoothly and completely without relying on the mechanical forces of the prior art.

Based on the above object, the present invention connects the open end of the pressure water return piping to one end of the siphon pipe at a position sufficiently lower than the height of the pressurized water in the pressure chamber of the filter press, and The lower end is submerged in water in a water tank for pressurized water supply, for example, in a water-tight state. Therefore, after squeezing, the pressurized water in the pressurized chamber is automatically returned to the inside of the water tank or the like by the siphon principle, that is, by natural force. Therefore, there is no need for a suction source such as a conventional vacuum pump, which simplifies the equipment.
It also becomes easier to operate and control.

Hereinafter, the structure and operation of the present invention will be specifically explained based on an embodiment shown in the drawings.

First, the diaphragm compression type filter press 1 supports a plurality of filter plates 3 in a parallel movable state with respect to a fixed frame 2, and one fixed end plate 4.
The filter cloth 6 can be sandwiched between the movable end plate 5 and the other movable end plate 5. A diaphragm 7 is attached to, for example, one side of the filter plate 3, and a pressurized chamber 8 is formed between each filter plate 3 and the diaphragm 7. Note that the stock solution A is supplied from the slurry supply port 9, and the cleaning water B and the compressed air C for cleaning are sent from the cleaning supply port 10.

The pressure water return device 11 of the present invention connects the pressure water return pipe 13 in a branched state with the operation valve 14 interposed in the pressure water supply connecting pipe 12, and pressurizes the lower end of the pressure water return pipe 13. It is connected to one end of the siphon pipe 15 at a position sufficiently lower than the chamber 8, for example, a water head difference H=2 m or more below, and the lower end portion of this siphon pipe 15 is connected to, for example, make-up water D of a water tank 16 for supplying pressure water.
It is facing inside. Further, the connecting pipe 12 is
Pressure water supply piping 17 with operation valve 19 interposed
is connected to the discharge port of a pump 18 for supplying pressure water, and the suction port of this pump 18 is connected to the water tank 16.

In this embodiment, the actual length of the siphon pipe 15, that is, the water sealing depth, is necessarily determined by the water head difference between the filter press 1 and the water surface of the water tank 16. As mentioned above, the water head difference H is 2 m or more, so theoretically, the siphon pipe 1
The lower end of 5 may only be in contact with the water surface of makeup water D.

Next, the outline of the operation of the filter press 1 and the operation of the pressure water return device 11 will be explained.

First, in the first frame closing step, the movable end plate 5 sandwiches the filter plate 3 with the fixed end plate 4, so the filter cloth 6 between the filter plates 3 forms a sealed filter chamber 6a. . In the next filtration step, the stock solution A is supplied from the slurry supply port 9 to each filter chamber 6a. Pressure water E is supplied into the pressurizing chamber 8 between the diaphragm 7 and the filter plate 3 for the subsequent squeezing process. That is, the pump 18 for supplying pressurized water sucks in makeup water D from the water tank 16 and supplies it as pressurized water E with a predetermined pressure value to the inside of each pressurizing chamber 18 through the open operating valve 19 and the connecting pipe 12. and inflate the diaphragm 7. Of course, at this time, the operating valve 14 is closed. Therefore, the inside of the siphon pipe 15 remains full of water without air replacement. As a result, the diaphragm 7 squeezes the stock solution A inside the filter chamber 6a, discharges the filtrate to the outside through the filter cloth 6, and forms the solid content in the stock solution A as a cake inside the filter chamber 6a. .

After this, the pressure water return operation is started. In the pressure water return operation, first, the operating valve 19 is closed, and then the operating valve 14 is opened. At this time, the pressurizing chamber 8,
The interiors of the connecting pipe 12, pressure water return pipe 13, and siphon pipe 15 are always filled with water and are in a water-sealed state. In this way, the diaphragm 7
Since the filtration chamber 6a side of the filter chamber 6a communicates with the atmosphere through the filtrate discharge path and mud supply port, the pressurized water E inside the pressurization chamber 8 is released by the squeezing pressure that had been applied until then, and is released through the diaphragm 7 to a large extent. Since it receives atmospheric pressure, a siphon phenomenon occurs due to the water head difference H between the pressurized chamber 8 and the water tank 16, and the pressurized water inside the pressurized chamber 8 is returned to the inside of the water tank 16 by natural force without leaving behind. It will be done. In this way, the diaphragm 7 returns to a position where it is in close contact with the surface of the filtrate 3. This siphon phenomenon is
This is caused by the atmospheric pressure acting on the side surface of the filter chamber 6a of the diaphragm 7, and in addition to the siphon phenomenon described above, the return of the pressurized water E is caused by supplying compressed air to the outer surface of the diaphragm 7, that is, inside the filter chamber 6a. , is made more reliable by assisting the siphoning operation. After this, the opening/discharging process and the cleaning process are sequentially performed.

In the above embodiment, the lower end of the siphon pipe 15 faces the inside of the make-up water D of the water tank 16, but this siphon pipe 15 can be placed in another water tank where the necessary water head difference H can be obtained or directly connected to the water. Of course, it is also possible to submerge it inside water.

The present invention provides the following effects.

First of all, the pressure water in the pressure chamber is naturally discharged to the outside by the siphon effect caused by atmospheric pressure, so there is no need for a vacuum pump or the like, and no mechanical equipment is required. is not required, and the device can be simplified accordingly.

Secondly, since the discharge of pressurized water can be automatically started only by opening and closing the operating valve, the operation is simpler and the control thereof is simpler than in the prior art.

Furthermore, thirdly, even when the present invention is applied to existing equipment, it can be implemented with a simple slight change in piping, so the apparatus of the present invention can be easily applied to existing equipment.

[Brief explanation of drawings]

The figure is a piping diagram of a pressure water return device for a filter press according to the present invention. 1...Diaphragm compression type filter press, 3...Filter plate, 6...Filter cloth, 6a...Filter chamber, 7
... diaphragm, 8 ... pressurization chamber, 11 ... pressure water return device, 12 ... connection pipe, 13 ... pressure water return piping, 14 ... operation valve, 15 ... siphon pipe,
16...Aquarium.

Claims (1)

[Scope of utility model registration request] In a filter press in which a large number of filter chambers are formed by a filter plate having a diaphragm, and the stock solution in the filter chamber is compressed by supplying pressure water into the pressure chamber of the diaphragm, the pressure water return piping is connected to the filter press. A pressure water return device for a filter press, characterized in that it is connected to a siphon pipe that is disposed below a chamber and submerged in water.