JPH04190890A - Sewage treating device - Google Patents

Abstract

PURPOSE:To control the growth of a cake layer, so that the cake layer does not exceed its predetermined thickness, by a method wherein the flow of the liq. to be treated is caused to act, as shearing force, upon the cake layer formed on the surface of filter material to scrape off the cake layer. CONSTITUTION:In a zone A, the liq. 2 to be treated is separated into filter cake and liq. by undergoing the suction force caused by driving a filter liq. suction pump 14 and through the filter material 9 of each filter element 5. The liq. is sent from the filter material 9 through a filter liq. passage 7 of a filter plate 8, a filter liq. suction tube 11, a filter liq. suction header pipe 12 and a filter liq. suction pipe 13 and then discharged therefrom. The filter cake is adhered to the membrane surface of the filter material 9 in a cake layer. In the zone A, since the liq. 2 flows through a passage defined between the filter materials 9 parallel to the surface of the filter material, the flow of the liq. 2 acts, as shearing force, upon the cake layer formed on the surface of the filter material to scrape off the cake layer, whereby the growth of the cake layer is so controlled as not to exceed its predetermined thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sewage treatment apparatus that uses sewage water or the like as water to be treated.

Conventional technology Conventionally, in sewage treatment equipment that processes wastewater such as sewage water by membrane separation, a filter element such as an ultrafiltration membrane is adhered to the surface of a filter plate to form a filtration element. were arranged in parallel to form a membrane separation device. Then, the membrane separation device is immersed in the processing tank, and the cake layer adhering to the filter medium surface is peeled off by aeration of air ejected from an aeration pipe provided at the bottom of the processing tank, thereby cleaning the filter medium surface.

Problems to be Solved by the Invention However, in the conventional configuration described above, cleaning by aeration is performed by exposing the surface of the filter medium to an upward agitation flow generated by the air lift action of the air, so there is a problem that the filter medium may peel off or be damaged. there were. Furthermore, even if the filter media surface is cleaned by aeration, it is necessary to periodically take out the membrane separator and disassemble it for cleaning, and there is a problem in that the water to be treated in the treatment tank must be drained once when the membrane separator is taken out. .

In addition, at the initial stage of installation of a membrane separation device, it is necessary to immerse the filter material in a chemical solution or alcohol in order to perform hydrophilic treatment on the filter material. The work needed to be done and was difficult.

The present invention solves the above-mentioned problems, and aims to provide a sewage treatment device that can prevent damage to filter media and that allows easy handling of the membrane separation device during maintenance.

Means for Solving the Problems In order to solve the above problems, the present invention provides a partition wall in a processing tank that stores a liquid to be processed, and a plurality of filter media in one area of the processing tank partitioned by the partition wall. are arranged parallel to each other with a predetermined gap, and one area and the other area in the treatment tank separated by a partition wall are communicated, and the liquid to be treated flows in one area parallel to the filter medium. A circulation channel is provided as shown in FIG. .

Effect: With the above-described configuration, when the liquid to be treated is caused to flow by the liquid driving means, the liquid to be treated circulates through the circulation channel between one region and the other region.

At this time, the liquid to be treated flows parallel to the surface of the filter medium through the channel formed between the filter media in one region, so the flow of the liquid to be treated causes a shear force on the cake layer formed on the surface of the filter medium. Since the cake layer is scraped off, the growth of the cake layer is suppressed and the cake layer does not grow beyond a certain thickness. Further, since the cake layer is peeled off by the continuous flow of the liquid to be treated acting on the surface of the filter medium, the effect on the filter medium is small and the filter medium is not damaged.

Further, by closing an on-off valve provided in the middle of the circulation flow path, one region can be made independent from the other region, and there is no need to drain all of the liquid to be processed from the processing tank during maintenance. Furthermore, when performing hydrophilic treatment on the filter medium at the initial stage of installation, the capacity around the filter medium is reduced to the necessary minimum.

EXAMPLE An example of the present invention will be described below based on the drawings. 1st
As shown in FIG. 2, a supply pipe 3 for a liquid to be treated 2 such as sewage is opened at the top of a treatment tank 1, and the inside of the treatment tank 1 is divided into two areas A and B by a partition wall 4. ing. In one region A, a filtration unit 5 is disposed with its top portion immersed below the surface of the liquid to be treated 2 . The filtration unit 5 is an assembly formed by arranging a plurality of filtration elements 6 in parallel with a predetermined gap therebetween, and with the gaps formed between the filter plate elements 6 extending in the vertical direction. The filtration element 6 is formed by covering the surface of a filter plate 8 with a filtrate flow path 7 formed therein with a filter medium 9, and a gap is formed between the filter plate 8 and the filter medium 9. Pacer-IO is interposed.

The filtrate flow path 7 of each filter plate 8 is connected to a filtrate suction tube 11.
The filtrate suction header pipe 12 communicates with the filtrate suction pipe 13 via the filtrate suction header pipe 12 . Further, a filtrate suction pump 14 is interposed in the middle of the filtrate suction pipe 13.

Then, the liquid to be treated 2 is transferred to the other area B.
A stirrer 15 is provided as a liquid driving means for circulating the liquid over the area B and the other area B.

In addition, the upper part of the partition wall 4 is formed as an overflow layer 4a, and the bottom of the processing tank 1 corresponding to one region A and the bottom of the processing tank 1 corresponding to the other region B are connected to each other through a liquid feeding pipe. 16 is provided, and a circulation flow path is constituted by the liquid sending pipe 16 and the overflow layer 4a.

Further, an on-off valve 17 is interposed in the middle of the liquid sending pipe 16, and a discharge valve 18 for maintenance is provided at the bottom of the other region B.

Hereinafter, the operation of the above configuration will be explained.

When the liquid to be treated 2 supplied from the supply pipe 3 to the other area B of the processing tank 1 is made to flow by the stirrer 15, the liquid to be treated 2 flows into one area A over the overflow layer 4a, and flows into one area A. It circulates from area A to the other area B through the liquid feed pipe 16.

In one region A, the liquid to be treated 2 is separated into filter dregs and filtrate by the filter medium 9 of each filter element 5 under the suction force generated by the drive of the filtrate suction pump 14 . Further, the filtrate that has passed through the filter medium 9 passes through the filtrate flow path 7 of the filter plate 8 and is taken out through the filtrate suction tube 11, the filtrate suction header tube 12, and the filtrate suction tube 13. Further, the filter dregs adhere to the membrane surface of the filter medium 9 in the form of a cake layer.

The liquid to be treated 2 flows through the channel formed between the filter media 9 in one area A parallel to the surface of the filter medium, so that the flow of the liquid to be treated 2 flows into the cake layer formed on the surface of the filter medium. By acting as a shearing force on the cake layer and scraping off the cake layer, the growth of the cake layer is suppressed, and the cake layer does not grow beyond a certain thickness. Furthermore, since the cake layer is peeled off by the continuous flow of the liquid to be treated acting on the surface of the filter medium, the influence on the filter medium is small and the filter medium is not damaged.

Furthermore, by closing the on-off valve 17 provided in the middle of the liquid sending pipe 16, one region A can be made independent from the other region B, and all the liquids 2 to be treated in the processing tank 1 can be removed during maintenance. No need to remove it.

Furthermore, when the filter medium 9 is subjected to hydrophilic treatment at the initial stage of installation, the capacity around the filter medium is reduced to the minimum necessary.

In this embodiment, the flow of the liquid 2 to be treated in the other region is an upward flow, but it may be caused to flow downward from one region A to the other region B. Further, although a stirrer is used as the liquid driving means, the flow may be overflowed from the other area B to the one area A using the air lift effect due to aeration. Furthermore, the processing tank 1 may be of an open type or a closed type.

Then, as shown in FIG. 3, a liquid feeding pipe 17 is provided so as to communicate between the side of one area A and the side of the other area B,
The agitator 15 may also be arranged horizontally. In this case, the liquid to be treated 2 is circulated in the horizontal direction. The operation and effect are the same as in the previous embodiment.

Effects of the Invention As described above, according to the present invention, the flow of the liquid to be treated acts as a shearing force on the cake layer formed on the surface of the filter medium, and the growth of the cake layer is suppressed by scraping the cake layer. This can prevent the cake layer from growing beyond a certain thickness.

Furthermore, since the cake layer is peeled off by the continuous flow of the liquid to be treated acting on the surface of the filter medium, the effect on the filter medium is small and damage to the filter medium can be prevented.

Furthermore, by closing the on-off valve installed in the middle of the circulation flow path, one area can be made independent from the other, eliminating the need to remove all the liquid from the treatment tank during maintenance. When the filter medium is hydrophilized at the initial stage, the volume around the filter medium can be minimized.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a filtration device showing one embodiment of the present invention, Fig. 2 is a partially enlarged sectional view of a filtration element in the same embodiment, and Fig. 3 is a filtration device showing another embodiment of the present invention. FIG. 1... Processing tank, 2... Liquid to be treated, 4... Partition wall,
4a... Overflow weir, 8... Filter plate, 9... Filter material, 14
River filtrate suction pump, 15... Stirrer, 16... Liquid feeding pipe.

Claims (1)

[Claims] 1. A partition wall is provided in the processing tank that stores the liquid to be processed, and a plurality of filter media are arranged in parallel with a predetermined gap in one area of the processing tank partitioned by the partition wall. One area and the other area in the treatment tank are communicated with each other, and
A circulation channel is provided in one area so that the liquid to be treated flows parallel to the filter medium, an on-off valve is provided in the middle of the circulation channel, and the liquid to be treated is transferred to the other area between one area and the other area. A sewage treatment device characterized in that it is provided with a liquid driving means for circulating a liquid across the sewage treatment apparatus.