JPS597499A - Washing method of filter cloth - Google Patents

Abstract

PURPOSE:To wash filter cloth with a small amount of washing water by injecting washing water from nozzle which moves back and forth in the transverse direction of the filter cloth while the filter cloth is moving after removed flocculated sludge from a sludge suspension by a press type dehydrator. CONSTITUTION:Sludge water (a) and a flocculating agent (b) are put into a flocculation reaction tank 4 where the sludge is flocculated. The sludge suspension is supplied on the upper filter cloth 1a of a belt press type dehydrator 1. The sludge suspension is filtered and removed of the greater part of water with the cloth 1a, and is then sandwiched between said cloth and a lower filter cloth 1b, and is squeezed and dehydrated between both filter cloths as the filter cloths travel through plural dehydration rolls 12a-12f. The dehydrated sludge is removed when the upper and lower filter cloths are separated by the final roll 12f. The sludge stuck on both filter cloths is scraped with scrapers 14, 15 respectively. The filter cloths 1a, 1b are washed by the washing water from nozzles 2a, 2b which move back and forth in the transverse direction and the filter cloths are cyclically used again as the upper and lower filter cloths having no clog for dehydration of the sludge.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the method for cleaning r cloth, and more specifically, the method of cleaning r cloth in a roll press type, belt press type, or vacuum type dehydrator.
Concerning how to wash cloth.

Conventionally, when roll presses W and tc continuously separate solids from a solid-liquid mixture using a belt press type dehydrator, etc., the r cloth gradually becomes clogged due to continuous solid-liquid separation. Washing the cloth was essential.

FIG. 1 shows such a conventional P cloth cleaning method, in which after removing solids separated from a solid-liquid mixture, a spray pipe 2 is fixed in the width direction of the pP cloth 1, and 7 The nozzle 6) also sprays cleaning water in a fan shape over the entire width of the fabric 1, and the fabric 1 is continuously washed by moving the fabric 1, for example, in a direction perpendicular to the plane of the paper ( Also.

However, in such conventional cloth cleaning methods, the spray pipe 2 is fixed, so in order to avoid parts of the cloth from which cleaning water is not sprayed, the nozzle 6 also sprays a fan-shaped cleaning Hydropower: They overlapped with each other.

Therefore, the number of nozzles B naturally increases, and the amount of washing water becomes enormous. Furthermore, as the amount of washing water increases, the power of the washing water pump and the amount of water discharged also increase.

Therefore, the present invention has been made to eliminate such conventional drawbacks, and it greatly reduces the amount of washing water, allows effective washing of P cloth with a small amount of water, and reduces the power and drainage amount of the washing water pump. It has features such as being able to

That is, the cloth cleaning method of the present invention involves moving 8 in the longitudinal direction.
The solid is separated from the solid-liquid mixture using a cloth, the solid is dehydrated by pressing together with the first cloth, the dehydrated solid is removed from the first cloth, and then the solid is moved in the longitudinal direction. This method is characterized in that the washing water spraying means sprays washing water onto the r cloth while reciprocating the washing water spraying means in the width direction of the cloth.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 2 shows the process of separating sludge from a sludge suspension using a belt press dehydrator. Sludge a and flocculant are supplied to the flocculation reaction tank 4 and stirred by the stirrer 5 to flocculate the sludge a. After that, the flocculated sludge is passed through the flocculated sludge pipe 6 to the dehydrated material supply port 8 of the belt press dehydrator 7. supply to. Guide roll in belt press dehydrator 7? , meandering prevention roll 10
, tension roll 11, oyohi dehydration rolls 12a-1
After passing through 2f, the endless upper f cloth 1a is indicated by the arrow A K ?
'6, the lower cloth 1b is also moving in the longitudinal direction along the arrow B.

The flocculated sludge supplied to the dehydrated material supply port 8 is dehydrated using the Uesawa cloth 1a, and the r-liquid is collected in the r-liquid receiver 16. Upper P cloth 1
The flocculated sludge held on the top surface of a moves in the direction of arrow A,
First, in the dewatering roll 12a, the upper P cloth 1a and the lower cloth 1b are
The dewatering rolls 12b~
The water is dehydrated in the same manner at 12f, and the dehydrated liquid is collected in the r liquid receiver 13.

Next, with the dewatering roll 12f, the first fabric is again separated into the upper R fabric 1a and the lower P fabric.
The sludge is separated into cloths 1b, and the sludge on the upper cloth 1a is scraped off by a scraper 14, while the sludge on the lower cloth 1b is scraped off by a scraper 15, and moves according to arrows A and B, respectively.

Next, the upper R cloth 1a is washed by a jet of washing water from the spray pipe 2a that reciprocates in the width direction of the first cloth, and thereafter, the sludge is separated again in the same manner as described above, and the lower P cloth 1b is also washed in the same manner. After being washed with washing water jetted from the spray pipe 2b, the sludge is again subjected to dewatering.

The number of reciprocating movements of the spray tubes 2a t 2b can be arbitrarily selected, and is, for example, 50 times/min. still,
The number of nozzles B provided in the spray pipes 2a and 2b is also determined by selecting the pitch and stroke of the reciprocating motion of the spray pipes, and is, for example, 10 nozzles/m. The amount of water to be injected can also be determined depending on the type of material to be dehydrated, and is, for example, 3 to 6 m<3>/hr-m in the case of dewatering sludge.

Although FIG. 2 shows the case where the cleaning water is sprayed only from one side of the cloth, the present invention is not limited to this, and the cleaning water can be sprayed onto both sides of the cloth as necessary. You can also.

Here, as shown in FIG. 3, the spray pipe 2 used in the present invention is a spray pipe supported by a support member 18 using a separate drive unit 16 while supplying cleaning water from a flexible hose 17. 2 may be reciprocated in the width direction of the belt 1 as shown by arrow C, or as shown in FIG. A reciprocating motion can also be made by a worm gear transmission 22 connected to the fabric traveling roll 20 by a chain belt or a -belt 21.

In the case of FIG. 4, since the r cloth running power of the dehydrator is used for flJ, there is an advantage that the power cost is low.

As described above, according to the present invention, since the washing water is sprayed onto the r-cloth without reciprocating in the width direction of the r-cloth, the amount of washing water can be greatly reduced.

That is, as shown in FIG. 5, even if there is an unwashed portion Y between the r cloth portions X that are washed with the washing water sprayed from the nozzle 3 of the spray pipe 2, the width of the reciprocating movement of the spray pipe 2 is By making Z larger than IJ of Y, it is possible to eliminate clogging of the r cloth 1 and to wash it evenly.

Therefore, the number of nozzles B provided in the spray pipe 2 can be reduced to about half compared to the conventional fixed spray pipe system, and of course the amount of washing water can also be reduced substantially by half. As the amount of washing water is reduced, the power for supplying washing water can also be reduced, and the amount of wastewater is also reduced, so that the labor and cost for wastewater treatment can also be reduced.

The p-cloth cleaning method of the present invention is particularly effective when dewatering a large amount of sludge.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the main parts of a conventional p-cloth cleaning device, Fig. 2 is a process diagram showing an embodiment of the present invention, Figs. 3 and 4 are schematic diagrams of its main parts, and Fig. 5 is a diagram of the present invention. FIG. 3 is an explanatory diagram showing the furnace cloth cleaning effect of FIG. 1, 1a, 1b ・P cloth, 12a, 12b
-, 12c,' 12d. 12e, 12f--Press roll, 14, 15
=-Scraper, 2, 2a, 2b... spray pipe, 3 nozzle. Agent: Patent Attorney Shin Ogawa − Patent Attorney Ken Noguchi Patent Attorney Kazuhiko Saishita Figure 1 Figure 2

Claims (1)

[Claims] Separating solids from the solid-liquid mixture using a longitudinally moving p-cloth, dewatering the solids by continuously pressing them with the r-cloth, removing the dehydrated solids from the p-cloth, and then A method for washing r-cloth, characterized in that washing water is sprayed from the washing water spraying means onto the P cloth while reciprocating the washing water spraying means in the width direction of the washcloth moving in the longitudinal direction.