JPH04284888A - Tank for membrane separator in septic tank - Google Patents

Abstract

PURPOSE:To provide a membrane separating apparatus, which can be prevented from choking up with a little horsepower and is easy to be maintained and inspected, for a septic tank. CONSTITUTION:A separating membrane module 2 composed of a large number of tubular outer pressure-type superfine porous separating membranes 2A which are gathered in parallel vertically in a constant distance, is set upright in the bottom 3A of a septic tank. A gas dispersing aapparatus 3 is put in the central lower part of the separating membrane module 2, a treated water supplying pipe 4 having a lot of water passing mouths 4A in the circumferential wall is set in the upper part of the gas dispersing apparatus 3 and at the same time in the central vertical space 2B of the separating membrane module 2, and a pump 5 to supply the treated water W in the septic tank is installed in the treated water supplying pipe 4. Separating of adhering foreign substances is accelerated by combination of the water flow jetting toward the radial direction and rising bubbles.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a membrane separation device for a septic tank.

0002

[Prior Art] Conventionally, as a sewage septic tank, a sewage septic tank that purifies sewage through biological treatment using anaerobic microorganisms and aerobic microorganisms has been widely known. It is known to have a treatment tank using aerobic activated sludge.

[0003] This aerobic activated sludge treatment tank has the advantage that the contact rate between the treated water and the activated sludge is very high and that it can purify the sewage efficiently, but it is necessary to prevent the activated sludge from flowing out when discharging the treated water. Therefore, activated sludge treatment tanks are sometimes equipped with a separation membrane module that filters and discharges only the treated water.

0004

[Problems with the Prior Art] However, if filtration is performed in treated water in which activated sludge is dispersed, the separation membrane module is likely to become clogged, making maintenance management extremely troublesome. However, as a means to prevent such clogging, an air diffuser is used to generate an upward flow containing air bubbles with a large shear force at the bottom of a horizontally arranged separation membrane module. Generating an upward flow requires an air supply device with extremely high horsepower, which increases the cost of the device or hinders its miniaturization.

[0005]

[Problems to be Solved by the Invention] In view of the above-mentioned problems, it is an object of the present invention to provide a membrane separation device for a septic tank that can sufficiently prevent clogging with a small amount of horsepower and can be easily maintained and inspected. It has been done.

That is, in the membrane separation device for a septic tank of the present invention, a separation membrane module consisting of a large number of tubular external pressure type microporous separation membranes collected at regular intervals in parallel in the vertical direction is installed upright at the bottom of the septic tank, and the separation An air diffuser is arranged at the lower center of the membrane module, and a treated water supply pipe having a large number of water passage ports on the peripheral wall is arranged at the upper part of the air diffuser and in the central vertical space of the separation membrane module. It is characterized in that the treated water supply pipe is provided with a pump for supplying the treated water in the septic tank.

[0007]

[Example] Next, an example of the present invention will be described. FIG. 1 is a sectional view of an embodiment of the invention. A membrane separation device 1 for a septic tank according to the present invention has a separation membrane module 2 formed by collecting a large number of tubular external pressure type microporous separation membranes 2A...2A in parallel in the vertical direction at regular intervals for use in a septic tank, for example, an aerobic activated sludge treatment tank. An air diffuser 3 is installed upright on the inner bottom 3 and arranged at the lower center of the separation membrane module 2, and is located above the air diffuser 3 and within the central longitudinal space 2B of the separation membrane module 2.
Treated water supply pipe 4 having a large number of water ports 4A...4A on the peripheral wall
The treated water supply pipe 4 is provided with a pump 5 for supplying the treated water W in the septic tank.

In the figure, reference numeral 6 denotes a suction pump that sucks filtrate from the separation membrane module 2 made of a tubular external pressure type microporous separation membrane 2A, and is connected to a pipe 6A that discharges the filtrate to the outside. Further, 7 in the figure indicates an air supply pipe that supplies air to the air diffuser 3.

[0009]

[Operation] In the above, when the suction pump 6 is driven to filter and discharge the treated water, the aeration device 3 performs aeration, and at the same time the pump 5 is driven to transfer the treated water W in the septic tank to the separation membrane module 2. into the central longitudinal space 2B. When the suction pump 6 is driven, the inside of the membrane becomes negative pressure, which causes filtration from the outside to the inside of the membrane, and suspended matter such as activated sludge adheres to the membrane surface, but the flow of treated water W that blows out into the central vertical space 2B. Due to the combination of the force and the air bubbles rising from the bottom, a water flow is generated on the outer surface of the membrane in the direction shown by the arrow, making it easier for attached foreign matter to peel off.

0010

Effects of the Invention As explained above, the present invention uses a membrane separator in a vertical arrangement, generates a water flow from the center to the outside in the radial direction, and at the same time mixes many air bubbles into the water flow by aeration. Foreign matter adhering to the outer surface is efficiently removed and clogging is prevented for a long period of time. Furthermore, since the membrane separator is vertically arranged, it is easy to take out and insert, and subsequent maintenance and inspection work is also facilitated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the invention.

[Explanation of symbols]

1 Membrane separation device 2 Separation membrane module 2A Tubular external pressure type microporous separation membrane 2B
Central vertical space 3 Air diffuser 3A Septic tank inner bottom 4 Treated water supply pipe 4A Water inlet 5 Pump W Treated water

Claims (1)

[Claims] Claim 1: A separation membrane module consisting of a large number of tubular external pressure type microporous separation membranes collected at regular intervals in parallel in the longitudinal direction is installed at the bottom of the septic tank, and an aeration device is installed at the center lower part of the separation membrane module. A treated water supply pipe having a plurality of water passage ports on a peripheral wall is disposed in the central vertical space of the separation membrane module at the upper part of the aeration device, and the treated water supply pipe has a plurality of water inlets in the septic tank. A membrane separation device for a septic tank, characterized in that it is equipped with a pump for supplying treated water.