JPH1076261A - Water treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent filtration efficiency from being lowered by the clogging of a mud discharge opening by concentrated suspended substances by installing an air diffusing tube under a membrane module in a filtration tank, forming a precipitation part and the mud discharge opening in the bottom part of the filtration tank, and arranging a mud discharge opening clogging preventive means near the mud discharge opening. SOLUTION: A hollow fiber membrane module 3 is installed in a filtration tank 1, and an air diffusion tube 5 is fixed under the module 3. A precipitation part 9 is formed under the module 3, and suspended substances in raw water which were concentrated by filtration by the module 3 are precipitated to be accumulated in the precipitation part 9. The accumulated suspended substances are discharged at intervals of a prescribed time from a mud discharge opening 7 formed in the bottom part of the filtration tank 1 outside the tank 1. Moreover, a mud discharge opening clogging preventive means 8 is set near the discharge opening 7, a nozzle for supplying air from the outside of the tank 1 is introduced, and air is ejected from the opening of the nozzle to prevent the clogging of the discharge opening 7 by the suspended substances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment apparatus using a membrane module, and more particularly to a water treatment apparatus having a mud hole at the bottom of a filtration tank and having a function of preventing clogging of the mud hole. .

[0002]

2. Description of the Related Art A water treatment apparatus for obtaining filtered water from water to be treated containing suspended substances using a membrane module provided with a filtration membrane is widely used in the field of water purification, wastewater treatment, food production, and the like. Used in In particular, a water treatment apparatus using a hollow fiber membrane module in which a plurality of hollow fiber membranes are disposed as a filtration membrane has an advantage that a filtration membrane area can be larger than a water treatment apparatus using a flat membrane module, It is drawing attention as a mainstream water treatment system in the future.

[0003]

When the water to be treated is filtered using such a water treatment apparatus, the turbidity concentration in the filtration tank increases as the filtration treatment is continued, and the concentrated turbidity increases. It deposits on the sedimentation section provided at the bottom of the filtration tank. The accumulated turbidity is drained out of the filtration tank through a drainage port provided at the bottom of the filtration tank at regular intervals, and the nature of the turbidity contained in the water to be treated and the quality of the water to be treated Depending on the degree of concentration, the turbid matter deposited on the bottom clogs the mud outlet, and there is a disadvantage that the turbid substance cannot be discharged from the filtration tank. Once the spout is clogged with turbidity, it is necessary to temporarily stop the filtration cycle and clean the spout, resulting in very low filtration efficiency.

[0004]

In view of such inconveniences, the present inventors have developed a water treatment apparatus that does not cause a decrease in filtration efficiency due to a blockage of a drainage hole by a concentrated turbid substance. As a result of studies for development, the present invention has been accomplished.

That is, the gist of the water treatment apparatus of the present invention is to provide a water treatment apparatus in which a membrane module is provided in a filtration tank, and an air diffuser is provided below the membrane module, and a sedimentation section and a drain port are provided at the bottom of the filtration tank. In the water treatment apparatus, a means for preventing clogging of the exhaust port is provided in the vicinity of the exhaust port.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view showing an example of the concept of the configuration of the water treatment apparatus of the present invention. In FIG. 1, reference numeral 1 designates a filtration tank in which a membrane module 3 is disposed and in which filtration processing of water to be treated is performed. In the filtration tank, raw water from a river is subjected to wastewater treatment when water purification treatment is performed. In the case of performing treatment, city wastewater, factory wastewater, food wastewater, and the like are introduced from the introduction pipe 2 as treated water.

As the membrane module 3, a flat membrane module, a hollow fiber membrane module, a spiral type module or the like can be used. However, a large membrane area can be obtained, the apparatus can be made compact, and the efficiency of membrane cleaning by bubbling can be improved. It is preferable to use a flat hollow fiber membrane module in which hollow fiber membranes are laminated into a flat plate to form a module, from the viewpoint that the hollow fiber membrane can be used.

The hollow fiber membrane used in the hollow fiber membrane module includes a polyethylene hollow fiber membrane, a polypropylene hollow fiber membrane, a polyacrylonitrile hollow fiber membrane, a polysulfone hollow fiber membrane, and ethylene-vinyl alcohol, which have been subjected to a hydrophilic treatment. A hollow fiber membrane made of a copolymer or the like can be used.

The filtration by the membrane module 3 is performed by sucking the inside of the hollow fiber membrane module 3 by a filtration pump 4 provided outside the tank. Below the hollow fiber membrane module 3, an air diffuser 5 is provided. The conditions for air scrubbing from the air diffuser are appropriately set according to the properties of the water to be treated.

For example, when performing the water purification treatment using the water treatment apparatus of the present invention, it is preferable to alternately and intermittently perform the filtration treatment by the membrane module and the air diffusion from the air diffuser. Further, when performing the wastewater treatment by the present water treatment apparatus, the filtration treatment by the membrane module is performed while performing the aerobic treatment of the wastewater by aeration from the air diffuser.

The filtration tank has a sedimentation section 9 below the membrane module, and the suspended matter in the water to be treated, which is concentrated by filtration by the membrane module, sediments in the sedimentation section and accumulates. The turbidity deposited on the sedimentation section is discharged out of the filtration tank at regular intervals from a discharge port provided at the bottom of the filtration tank.

In the water treatment apparatus of the present invention, a means 8 for preventing clogging of the mud outlet is provided near the mud outlet. As shown in FIG. 1, in a water treatment apparatus in which a mud outlet is provided at the lowermost end of a filtration tank, it is preferable to provide a mud outlet clogging prevention means above the mud outlet. As a means to prevent clogging of the mud outlet, a nozzle that supplies air from outside the filtration tank is introduced, and air is diffused from the opening of the nozzle to prevent clogging of the mud outlet due to turbid matter. it can.

In this case, regardless of whether the opening of the nozzle is directed upward or downward of the filtration tank, a water flow due to aeration can be generated in the vicinity of the drain outlet, and thereby the drain can be discharged. It is possible to efficiently pulverize the turbid matter accumulated near the mud hole and prevent clogging of the mud hole, but preferably, if this opening is provided to the lower mud hole, By directly blowing air on the suspended matter deposited near the mouth, the suspended matter can be efficiently pulverized.

Further, as means for preventing clogging of the mud outlet,
It is good also as composition which sprays a fluid from a tip of a nozzle to an exhaust port. In this case, the fluid to be used may be water to be treated, raw water or concentrated water in a filtration tank.

It is preferable that the air diffusion or the spraying of the fluid from the nozzle opening end be performed immediately before or simultaneously with the sludge discharging operation. The time required for air diffusion or fluid spraying depends on the nature of the deposit, but the suspended turbid matter can be ground in about several seconds.

When the mud outlet is disposed above the bottom of the filtration tank as shown in FIG. 2, a nozzle is provided below the mud outlet so that the opening faces upward. Preferably, air or fluid is sprayed.

Further, as shown in FIG. 3, the air diffused from the air diffuser provided below the membrane module may also serve as a means for preventing the discharge port from clogging. In this case, the air diffuser which is provided in the air diffuser and diffuses the air is disposed toward the exhaust port. By employing a configuration in which the air diffused from the air diffuser also serves as a means for preventing clogging of the exhaust port, it is possible to pulverize the turbid matter deposited in the sedimentation section with good volumetric efficiency and energy efficiency.

[0018]

According to the water treatment apparatus of the present invention, a membrane module is provided in a filtration tank, and an air diffuser is disposed below the membrane module, and a sedimentation section and a drainage port are provided at the bottom of the filtration tank. In addition, since the exhaust port clogging prevention means is provided in the vicinity of the exhaust port, the exhaust port is not blocked by the concentrated turbidity, and thus the exhaust port clogged is cleaned. Since it is not necessary to stop the filtration cycle, long-term stable operation can be performed, and the filtration efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a water treatment apparatus of the present invention.

FIG. 2 is a sectional view showing another example of the water treatment apparatus of the present invention.

FIG. 3 is a sectional view showing another example of the water treatment apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Filtration tank 2: Introductory tube 3: Hollow fiber membrane module 4: Filtration pump 5; Aeration tube 6; Gas supply pump 7;

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masaru Uehara 2-3-1, Kyobashi, Chuo-ku, Tokyo Inside Mitsubishi Rayon Co., Ltd. (72) Inventor Tsutomu 2-3-1, Kyobashi, Chuo-ku, Tokyo Mitsubishi Rayon Co., Ltd.

Claims (4)

[Claims] 1. A water treatment apparatus having a membrane module in a filtration tank and an air diffusion tube below the membrane module, and a sedimentation section and a mud hole provided at the bottom of the filter tank. A water treatment apparatus provided with a mud clogging prevention means. 2. The water treatment apparatus according to claim 1, wherein a mechanism for diffusing air is used as the means for preventing clogging of the discharge port. 3. The water treatment apparatus according to claim 1, wherein a fluid spraying mechanism is used as a means for preventing clogging of the discharge port. 4. The air diffuser according to claim 1, wherein the air diffuser is provided with an air diffuser opening toward the mud outlet, and bubbling from the diffuser tube also serves as a mud outlet clogging prevention means. A water treatment apparatus as described in the above.