JPH08281079A - Flat membrane element for dipping type membrane separation apparatus - Google Patents

Abstract

PURPOSE: To prevent large inflation of membrane due to hydraulic pressure when permeated water within flat membrane element backflows through the membrane at the time of operation stop of the flat membrane element which is vertically arranged in the water and samples permeated water through the membrane and to enhance water sampling efficiency of permeated water. CONSTITUTION: This apparatus has a main frame 10 wherein membranes are stretched around on both of front and rear surfaces and each one is lined vertically keeping a flow passage interval toward front and rear. Flat membrane element for dipping type membrane separation apparatus samples permeated water filtrated through the membrane out of raw water streaming upward through flow passage interval. Projecting lines 17, 18 are formed projectingly contacting with flat membrane element arranged vertically toward front and rear, meeting cross like X on both surfaces front and rear wherein the main frame membrane is stretched around.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a main body in which membranes are stretched on both front and rear sides, and keeps a flow passage distance in the front-rear direction in water in a treatment tank such as a biological reaction tank or a membrane dipping tank. The present invention relates to a flat sheet membrane element of a submerged membrane separation apparatus that collects permeated water that has permeated through a membrane among raw water that flows upright in the flow path interval.

[0002]

2. Description of the Related Art In such a submerged membrane separator, membrane filtration is performed intermittently so that permeated water that has permeated the inside of a flat sheet membrane element when the operation is stopped flows back to the membrane so as to remove the deposits adhering to the outer surface of the membrane. The operation is carried out so that the membrane is peeled off to recover the filtration performance of the membrane and the permeated water is stably collected over a long period of time.

[0003]

When the operation is stopped and the permeated water is caused to flow back through the membrane, the water pressure causes the membrane to bulge toward the flow channel interval while bending the front and rear walls of the main body. In order to improve the efficiency of collecting permeated water per unit volume, it is necessary to narrow the flow channel intervals between flat membrane elements and increase the number of flat membrane elements that are lined up side by side.ゝ It is said that the membranes on the opposite surfaces of the flat membrane elements facing each other swell and come into contact with each other, scratching or adhering to each other, and even if the number of flat membrane elements is increased, the efficiency of collecting permeated water is not improved. The problem was the conventional flat sheet membrane element.

[0004]

Means for Solving the Problems The present invention is intended to solve the above-mentioned problems, and has a main body in which membranes are stretched on both front and rear surfaces, and flows in water in a treatment tank in the front-back direction. In a flat membrane element of a submerged membrane separation apparatus that collects permeated water that has permeated through a membrane among raw water that flows upward in the channel gap with a channel interval maintained, the membrane of the main body is stretched. It is characterized in that projecting ridges are provided on both of the front and rear surfaces so as to intersect with the front and rear flat sheet membrane elements in an X-shape so as to come into contact with each other.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the illustrated embodiment, 10 is a main body in which membranes 11 and 11 are stretched on both front and rear surfaces, 12 and 12 are water collecting passages which are integrally provided on both left and right sides of the main body and also serve as spacers. Is a cavity whose top and bottom are closed, and a permeated water outlet 13 that communicates with the inside of the hollow projects from the upper end.

The main body is, as shown in FIG.
The front and rear walls 15, 16 on which the membrane 11 is stretched are provided between the two, and water-permeable spacers 14 such as tricot knitted fabric having both sides projecting into the water collection channels 12, 12 are provided between the front and rear walls. There is.

The above-mentioned water collecting channels 12 and 1 which also serve as spacers
The front and rear surfaces of 2 are the front and rear walls 15 of the main body as shown in FIG.
When a plurality of flat sheet membrane elements protruding from 16 are arranged in a row in the front-rear direction in the tubular holding frame 20, the front and rear surfaces of the water collection channel come into contact with each other to form the flow passage interval 21 between the flat sheet membrane elements. Form.

On the front and rear walls 15 and 16 of the main body, a plurality of vertical ridges 17 and 18 which are inclined with respect to the vertical are projected at approximately equal intervals. The front and rear surfaces of the protrusions 17 and 18 and the front and rear surfaces of the water collecting passages 12 and 12 also serving as spacers are the same vertical surface.

The front and rear walls 15, 16 are formed between the water collecting channel 12 which also serves as a spacer and the ridges 17 and 18 and have a substantially right-angled triangular opening, ridges 17 and ridges 18. There is a parallelogrammic opening between them, and the aforementioned membrane 11 is stretched on the outer surfaces of the front and rear walls 15 and 16 by adhering or welding the peripheral edges to the edges of these openings 19.

The ridges 17 on the front wall 15 and the ridges 1 on the rear wall 16
Although the inclination of 8 is the opposite, the flat membrane element is centerline XX
When folded back at ´, they are point-symmetrical. Therefore, as described above, a plurality of flat sheet membrane elements are arranged in a line in the front-rear direction in the holding frame 20, and the water collecting channel 1 also serving as the spacer is provided.
When the front and rear surfaces 2 and 12 are brought into contact with each other, the protrusion 17 and the protrusion 18
Touch each other in an X shape. By intersecting in the X-shape in this way, the flow path interval also becomes the X-shape, so that a turbulent flow is generated in the flow and the effect of separating the gel layer on the film surface is further improved.

[0011]

As is apparent from the above, according to the present invention, the ridges 17 and 18 reinforce the front wall 15 and the rear wall 16 of the main body, and the permeated water in the main body during the operation of the intermittent operation is stopped. Even if water pressure is applied to the membrane in order to flow back through the membrane, the ridges 17 on the front wall and the ridges 18 on the rear wall of the flat membrane elements adjacent to each other in the front and rear direction
Since X and X are in contact with each other in an X shape, the front wall and the rear wall cannot be bent, and accordingly, the bulge of the film is small. For this reason, even if the flow path interval is narrowed and the number of flat membrane elements used is increased, damage to the membrane and adhesion of the membrane can be prevented, and the efficiency of collecting permeated water per unit volume can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a flat sheet membrane element according to the present invention.

FIG. 2 is a perspective view of two flat sheet membrane elements forming a flow path interval.

FIG. 3 is a plan view of FIG.

FIG. 4 is an enlarged sectional view taken along the line AB of FIG.

FIG. 5 is a plan view of a membrane module including a plurality of flat membrane elements.

[Explanation of symbols]

 10 Main Body of Flat Membrane Element 11 Membrane 12 Water Collection Channel that also serves as Spacer 13 Permeate Outlet 14 Water-permeable Spacer 15 Front Wall of Main Body 16 Rear Wall of Main Body 17 Front Wall Projection 18 Rear Wall Projection 19 Opening 20 Holding frame 21 Flow path interval

Claims (1)

[Claims] 1. A main body having membranes stretched on both front and back sides,
A flat plate of an immersion type membrane separation device that collects the permeated water that has permeated through the membrane among the raw water that flows upward in the flow path interval in a row in the water in the treatment tank while keeping the flow path interval in the front-rear direction. In the membrane element, projections are provided on both front and rear surfaces of the main body, on which the membrane is stretched, so as to intersect with the front and rear flat membrane elements in an X-shape so as to come into contact with each other. Flat membrane element.