JPH01123610A - Method and apparatus for batch filtration - Google Patents

Abstract

PURPOSE:To obtain the apparatus of improved treatment capacity by revolving three filter surfaces constituting a triangular shape around a revolving shaft and carrying out filtration, discharging of cake and washing in order. CONSTITUTION:Three filter surfaces A, B, C having filter cloth is provided in a casing 1 so as too cross-sectionally form a regular triangle. These filter surfaces are fixed to the revolving shaft 2A, 2B and rotatable with the shaft. Filtration is carried out on a 1st filter surface A, discharge of cake on a 2nd filter surface B and washing on a 3rd filter surface C. After these operations are finished, each filter surface is rotated to shift the operation to carry out filtration, discharge of cake and washing respectively, and then these operations are repeated. As the filtration, the discharge of cake and the washing are carried out in each independent position, the washability of filter cloth is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a filtration method using three filtration surfaces and an apparatus therefor.

[Background of the invention]

One type of filtration machine is a tray filter, which has only one filtration surface. After filtration, the filtration surface is turned over 180 degrees and the cake is transferred onto a discharge conveyor located below it. After discharging, cleaning was performed by spraying a cleaning liquid from below onto the filter surface after the cake had peeled off.

However, in this type of process, the steps of filtration, cake discharge, and washing are sequentially performed, so the throughput per hour is small. Furthermore, there is a risk that the cake discharge chute and the cake discharge conveyor may be wetted by the cleaning liquid, which may increase the moisture content of the dehydrated cake. In order to prevent this, the amount of cleaning liquid must be reduced, but in this case, the filter cloth cannot be washed sufficiently, leading to poor filtration performance and shortening of the life of the filter cloth.

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide a filtration method and an apparatus therefor, which have improved processing capacity and excellent filter cloth cleanability.

[Means for solving problems]

In order to solve the above-mentioned problems, the method of the present invention is such that three filtration surfaces having a substantially triangular cross section co-rotate around the center of rotation, and the first filtration surface of each filtration surface is Filtration is carried out, cake discharge is carried out on the second filter surface, and washing is carried out on the third filter surface, and then, when the operation is completed, the position of each filter surface is made different from the preceding operating position by said co-rotation. The method is characterized in that the operations of filtration, cake discharge, and washing are performed, and thereafter the above-mentioned operations are performed in order.

Furthermore, the device of the present invention includes three filtering surfaces disposed within the casing and substantially triangular in cross section; a horizontal rotating shaft that commonly supports these filtering surfaces and extends to the outside of the casing; a rotation drive means for rotating the horizontal rotation shaft around its axis; three fluid passages facing the inner surface of each of the filtration surfaces and extending to the outside of the casing through the horizontal rotation shaft; during a filtration operation; The first of the fluid passages
The fluid path is connected to the filtration suction device, the second fluid path is connected to the cake discharge pressure device, and the third fluid path is blind,
a flow path switching means configured to switch these communication modes with the rotation and provided between the horizontal rotation shaft and the suction device and the pressure air device; filtration in which the first flow path is connected; a supply port for the liquid to be filtered facing above the surface; and the third
A cleaning means for spraying a cleaning liquid onto the outer surface of the filtration surface facing the flow path; and;

[For production]

In the present invention, three filtration surfaces (which can also be referred to as filter cloth surfaces) are arranged in a triangular cross section, and since they rotate together, when filtering on a certain first filtration surface, The cake generated in the previous filtration operation can be discharged on the second filtration surface, and the filter cloth from which the cake has been discharged can be washed on the third filtration surface, and the washed filter cloth can be filtered. can be moved into position. Therefore, the processing capacity is greatly improved compared to the conventional one.

In addition, since filtration, cake discharge, and washing are performed at independent locations, the filter cloth can be easily washed, improving filtration performance and extending the life of the filter cloth.

[Specific structure of the invention]

The present invention will be explained in more detail below with reference to embodiments shown in the drawings.

In the figure, 1 is a casing fixed to the ground, and a partition plate 1a is provided at the widthwise center of the lower part of the casing, which divides the casing into a cake outlet IA and a cleaning liquid outlet IB. Also, provided within the casing are three filter surfaces A, B, and C having a filter cloth and forming a transverse rotation triangle. These filter surfaces A and B.

C is a structure in which a filter cloth is placed in a holding frame so as to be open to the outside, and these are integrated and attached to horizontal rotating shafts 2A and 2B that extend to the outside of the casing 1. Horizontal rotation axis 2
A and 2B are rotatably supported by bearings 4 and 4 provided on the frame 3.3. At the end of one rotating shaft 2B,
A sprocket 5 is fixed, and a chain 9 is wound between a rotary drive motor 6 and a sprocket 8 attached to an output shaft of a speed reducer 7. With this, 3
The three filter surfaces A, B, and C co-rotate. As this rotation mechanism, in addition to a chain system, appropriate means such as a gear or a motor direct connection system can be used.

In addition, as will be explained later, the filter surfaces A, B, and C are
In order to rotate and stop at every 120 degrees, a trigger 10a and a proximity switch 10 at every 120 degrees are connected to the rotation drive means.
It is a combination of b.

On the other hand, referring to FIG. 1, a supply port 11 for a liquid to be filtered such as sludge is arranged on the filtration surface A, and as shown in FIG.
The liquid to be filtered in the feed tank 12 is transferred to the feed pump 13
The water is guided to the supply port 11, and is supplied onto the filtration surface A from there. Also, as shown in FIG. 1 again, a cleaning liquid nozzle 14 is provided on the outside of the filtration surface C and directed thereto.

The other rotating shaft 2A has a first flow path 21p1 and a second flow path that extend through it in the longitudinal direction and are spaced at 120 degree intervals along the center line thereof and form part of the first to third flow paths referred to in the present invention. A passage 22p and a third passage 23p are formed, and the first to third pipes 21q', 22q, and 23q, which form part of the passage communicating with these, extend to the longitudinal center of the filtration surfaces A, B, and C. and extending therefrom from each filtration surface A.

It connects to the inside of the filter cloths B and C.

Further, a fixed shaft 15 is abutted against the outer end surface of the rotating shaft 2A, and a guide channel 21r is provided inside the fixed shaft 15 at a position corresponding to the first channel 21p and the second channel 22p.

22r is provided. The position corresponding to the third flow path 23p is blind. Furthermore, the fixed shaft 15 is the rotating shaft 2A.
It is pressed by a spring 16 to prevent leakage. As a result, the fixed shaft 15 and the rotating shaft 2A
The interface with the material becomes the sliding surface.

Furthermore, as shown in FIG.
2r is connected to a filtrate tank 24, a filtrate pump 25 as a suction device for filtration, a vacuum pump 26, and a steam/water separator 27, and a pressure air path 28 branches from the conduit 22r and serves as a pressure air device for discharging cake. It is connected to a compressor 29.

In the device configured as described above, the following operations are performed. First, as shown in FIG. 1, when the filtration surface A faces upward, a liquid to be filtered, such as sludge, is supplied onto the filtration surface A from the liquid supply port 11.

Thereafter, the filtrate pump 25 is started, and suction is performed from the back side of the filter cloth through the first flow path, that is, the first pipe 21q, the first flow path 21p, and the conduit 21r, and a filtration operation is performed on the filtration surface A. Ru. Next, each filter surface A, B,
When C is rotated 120 degrees, the compressor 29 is started, and the pressure from there is passed through the pressure air path 28, the conduit 22r, the second flow path 22p and the second pipe to remove the cake remaining from the previous filtration operation. The cake is supplied from the inside to the outside of the filtration surface B, and the cake is discharged. Furthermore, at the same time as the cake peeling operation, a cleaning liquid is projected from the cleaning liquid nozzle onto the filter surface C from which the cake has been peeled off, thereby cleaning the filter cloth.

Such operations will subsequently reduce each filter surface A, B, and C to 120
It is repeated one after another while rotating intermittently.

This detailed operation is shown in FIG. 6, but there is no need to explain it again.

In addition to the above-mentioned examples, a commonly used swivel system or the like can be used as the flow path switching means in the present invention.

〔Effect of the invention〕

As described above, according to the present invention, the filtration processing capacity is increased and the cleanability of the filter cloth is improved.

[Brief explanation of the drawing]

Fig. 1 is a view of the filtration device according to the present invention taken along line 1-■ in Fig. 3, Fig. 2 is an overall view of the equipment, Fig. 3 is a front view of the main body, and Fig. 4 is a section of the flow path switching means. FIG. 5 is a detailed view of the rotational drive mechanism of the filter surface, and FIG. 6 is a time flow chart of the operation. A, B, C...filtration surface, 1...casing, 2A. 2B...Horizontal rotating shaft, 11...Filtered liquid supply port,
14...Cleaning liquid nozzle, 15...Fixed shaft, 21p~
23p...flow path, 21q-23q...pipe, 21r,
22r... - Conduit, 25... Filtrate pump, 29
···compressor. Figure 4 Figure 5

Claims (2)

[Claims] (1) Three filtration surfaces having a substantially triangular cross section are made to co-rotate around the rotation center, and the first filtration surface performs filtration and the second filtration surface discharges the cake. are washed on the third filtration surface, respectively.
Then, when the operation is completed, the filtration, cake discharging, and washing operations are performed by changing the position of each filtration surface from the preceding operation position by the co-rotation, and thereafter the above-mentioned operations are performed in order. A batch filtration method. (2) three filtration surfaces disposed within the casing and substantially triangular in cross section; a horizontal rotation shaft that commonly supports these filtration surfaces and extends to the outside of the casing; rotation drive means for rotating the filter around its axis; three fluid passages facing the inner surface of each of the filtration surfaces and extending to the outside of the casing through the horizontal rotation axis; during a filtration operation, the fluid passages Of these, the first fluid path is connected to the filtration suction device, the second fluid path is connected to the cake discharge pressure device, and the third fluid path is blind, so that the communication mode of these can be switched in accordance with the rotation. and a flow path switching means provided between the horizontal rotating shaft and the suction device and the pressure air device; a supply port for the liquid to be filtered facing above the filtration surface to which the first flow path is connected; A batch type filtration device comprising: cleaning means for spraying a cleaning liquid onto the outer surface of the filtration surface facing the three channels;