JPS621523B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter press and a filtration method using the filter press.

As is well known, in a filter press, a plurality of filter disks are arranged side by side in a machine frame, and after the filter cloth is interposed between the filter disks and compressed, the liquid to be treated is forced into the filter chamber formed in the filter cloth. This is a filtration device that performs filtration. This type of filter press has the great advantage of being able to freely adjust the filtration area by increasing or decreasing the number of filtration disks, and easily obtaining a large filtration area. On the other hand, the filtration efficiency is low, the cake after filtration has a high water content, requiring time and effort for post-treatment, and it is difficult to peel the cake from the filter cloth.

The present invention aims to improve the above-mentioned drawbacks of the conventional filter press, improve the filtration efficiency, reduce the moisture content of the cake, and make it easier to peel the cake from the filter cloth. In order to uniformly precoat the fabric, the main idea is to connect the precoat pipe and the precoat discharge pipe directly within the filter chamber.

To explain the present invention with reference to an embodiment shown in the drawings, reference numeral 1 denotes a machine frame, and a pair of front and rear side frames 2, 2 and It consists of rails 4, 4 extending on both sides of the side frames 2, 2. Reference numeral 5 denotes a filter disk, which has numerous protrusions 6 formed on its surface, has a through hole 7 for the liquid to be treated in the center, has a through hole 8 for the precoat liquid at the top, and has a through hole 9 at the bottom. A filtrate discharge hole 10 is provided. Further, arm portions 11 are extended from both sides of the filter disk 5, and rollers 12 are rotatably attached to each of the arm portions 11, and by riding on the rails 4 of the machine frame 1, a plurality of rollers 12 are mounted. The filter disks 5 are slidably arranged in parallel on the machine frame 1. The plurality of filter disks 5 are sandwiched between a front plate 5A and a rear plate 5B.
A communication hole 7A and a filtrate discharge hole 10A are provided in the center of the back plate 5B, and a precoat liquid communication hole 8B is provided in the upper part of the rear plate 5B.The front plate 5A is fixed to the side frame 2, but the rear plate 5B is Like the filter disk 5, it is slidably supported by the machine frame 1. 13 is valve 13
A, a press-in tube for the liquid to be treated through which the pump 14 intervenes, and includes the communication hole 7A of the front plate 5A, the communication hole 7 of the filter plate 5, the communication hole 8, and the communication hole 8B of the rear plate 5B.
15 is a pre-coat discharge pipe with a valve 16 interposed therebetween, which communicates with the pre-coat tank 17; 18 is a filtrate discharge pipe with a valve 19 interposed between the filtrate discharge hole 10A of the front plate 5A and the filtrate of the filter plate 5. The filtrate discharge pipe 18 is connected to the discharge hole 10, and 20 is a precoat filtrate discharge pipe with a valve 20A interposed therebetween.
It is branched from and connected to pre-coat tank 17,
Reference numeral 21 is a recovery pipe, and a valve 22 is interposed between the press-in pipe 1
3, which is branched off from the press-fitting pipe 13, and 23 is an air conduction pipe with a valve 24 interposed therebetween, and is branched from the press-fit pipe 13, and 25 is a connecting pipe with a valve 26 interposed between the pre-coat tank 17 and the pump 14. Contact with the suction side. A hydraulic cylinder 27 is attached to the side frame 2 of the machine frame 1, and is supplied with pressure oil by a pump 28, and operates the filter disk 5 between the front plate 5A and the rear plate 5B by means of a piston rod 29. Tighten. A cake receiving tank 30 is installed directly below the filter disk 5.

In the above configuration, the filter cloth 31 is brought into contact with both sides of the filter disk 5, and then the filter disk 5 is compressed by the hydraulic cylinder 27, so that the filter cloth 31 is interposed between the filter disks 5. The filter cloth 31 has conductive holes 3 corresponding to the filter disks 5.
2, a communication hole 32 and a filtrate discharge hole 34 are provided. Further, a hollow flange bolt 35 is inserted through the through hole 32 of the filter cloth 31 and the through hole 7 of the filter disk 5, and a flange nut 36 is screwed onto the tip of the bolt 35. Furthermore, the communication hole 3 of the filter cloth 31
A hollow flange bolt 37 is inserted through the communication hole 8 of the filter plate 5 and the front plate 5. A flange nut 38 is screwed onto the tip of the bolt 37.
The filter cloth 31 in contact with A is provided with a conduction hole 32 and a filtrate discharge hole 34, and the conduction hole 32 of the filter cloth 31 and the conduction hole 7A of the front plate 5A are connected by inserting a hollow flange bolt 35. on the other hand, the rear plate 5B
The filter cloth 31 in contact with the filter has a communication hole 33 and a filtrate discharge hole 3.
4 is provided, and the communication hole 33 of the filter cloth 31 and the rear plate 5
It is communicated with the communication hole 8B of B by inserting a hollow flange bolt 37. Thus, the filter cloth 31 is fixed to one side of the front plate 5A, both sides of the filter plate 5, and one side of the rear plate 5B, thereby forming a filter chamber 31A inside. Prior to the filtration process, the pre-coat liquid (mixed liquid of the liquid to be treated and the filter aid of diatomaceous earth and bentonite liquid) in the pre-coat tank 17 is transferred to the valve 2.
6 is opened and introduced into the filter chamber 31A from the communication pipe 25 by the pump 14 via the press-in pipe 13. At this time, the valve 13A of the press-fit pipe 13 is kept closed. The precoat liquid introduced into the filter chamber 31A
It spreads into A through the conduction hole 7 and the communication hole 8, and is eventually returned to the precoat tank 17 from the precoat discharge pipe 15. As the precoat liquid is thus circulated, it is stirred and the filter aid is uniformly dispersed in the precoat liquid. At this point, when the valve 16 of the precoat discharge pipe 15 is gradually closed, the precoat liquid in the filter chamber 31A is Injection pressure is now applied to the filter cloth 31, and the precoat liquid
The filter aid, such as diatomaceous earth, forms a pre-coated film on the filter cloth, and the filtrate reaches the filtrate discharge pipe 18 through the guide hole 9 and the filtrate discharge hole 10, and when the valve 20A is opened, the pre-coated filtrate discharge pipe 20 returns to the precoat tank 17. In this way, the precoat is evenly spread over the surface of the filter cloth 31. Next, close the valve 26 of the communication pipe 25 and close the valve 1 of the press-fit pipe 13.
3A, the liquid to be treated is forced into the filter chamber 31A, and the liquid to be treated is filtered by the filter aid and the filter cloth 31 in the filter chamber 31A, and the filtrate is passed through the introducing hole 9. The filtrate discharge hole 10 leads to the filtrate discharge pipe 18, and the valve 19 is opened to discharge the filtrate. At this time, the valve 20A of the precoat filtrate discharge pipe 20
Keep it closed. When the filtration is finished, stop the pump 14, open the valve 22 of the collection pipe 21, and open the filtration chamber 31.
The remaining liquid to be treated is collected into the pre-coat tank 17, the pulp 22 is closed, the valve 24 of the air conduit 23 is opened, and the compressed air is sent into the filter disk through the press-in tube 13 and accumulated between the filter cloths 31. The liquid in the cake and the liquid in the filtrate discharge pipe 18 are recovered. In this way, the hydraulic cylinder 27 is moved backward to release the pressure on the filter plate 5 via the rear plate 5B, and the filter plate 5 is opened.
Tank 17 for receiving cake accumulated in filter cloth 30
Collect within.

The present invention is not limited to the above embodiments. For example, in this embodiment, a press-fit tube was used as the pre-coat tube for introducing the pre-coat liquid into the filter chamber, but the pre-coat tube was provided separately from the press-fit tube. However, the communication hole 8 of the filter disk 5 is not necessarily required.

Since the present invention has the above configuration, when precoating is performed, the precoat liquid is filled into the filter chamber from the precoat pipe and the precoat liquid is discharged from the precoat discharge pipe, thereby preventing pressure from being generated in the filter chamber. By distributing and circulating the pre-coat liquid throughout the filter chamber, the pre-coat liquid can be stirred and the filter aid can be uniformly dispersed, and when the pre-coat discharge pipe is then closed, pressure is created in the filter chamber for the first time. If the pre-coat liquid is filtered in this way, the filter cloth surface will be uniformly pre-coated with the filter aid, and in the subsequent filtration process, the filtration efficiency will be improved and the moisture content of the cake will be reduced.
Moreover, the cake adheres to the filter cloth surface via the precoat layer and can be easily peeled off from the filter cloth surface. Note that if precoating is performed, fine filtration can be performed even if a coarse filter cloth is used, so that clogging of the filter cloth is less likely to occur, and filtration efficiency is improved in this respect as well.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention.
The figure is a cutaway side view of the main part, Figure 2 is a sectional view taken along A-A' in Figure 1, Figure 3 is a front view of the filter cloth fixed to the filter disk, and Figure 4 is B-- in Figure 3. B′ cross-sectional view. In the figure, 1... Machine frame, 5... Filter plate, 13... Press-fit pipe (pre-coated pipe), 15... Pre-coated discharge pipe, 17
...Precoat tank, 18...Filtrate discharge pipe, 31...
Filter cloth, 31A...filter chamber.

Claims (1)

[Scope of Claims] 1. A machine frame, a plurality of filter disks slidably arranged in parallel within the machine frame, and a filter cloth sandwiched between the plurality of filter disks to form a filter chamber inside. A filter press comprising: a press-in pipe and a precoat discharge pipe that directly communicate with the filter chamber; a filtrate discharge pipe that communicates with the filter chamber via a filter cloth; and means for clamping the plurality of filter disks. 2. A machine frame, a plurality of filter disks arranged in parallel in a slidable manner within the machine frame, a filter cloth sandwiched between the plurality of filter disks and forming a filter chamber inside, and a filter cloth directly inside the filter chamber. A filter press comprising a press-in pipe, a pre-coat pipe, and a pre-coat discharge pipe that communicate with each other, a filtrate discharge pipe that communicates with the filter chamber through a filter cloth, and a means for clamping the plurality of filter disks.