JPH1024221A - Gas-liquid separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-liquid separator capable of reducing the generated amount of waste washing water generated by washing hollow fiber membrane elements. SOLUTION: A space formed between membrane protecting tubes 11 and a casing 13 is filled with packing 38 so that overflow holes 24 made in the upper end peripheral surfaces of the membrane protecting tubes 11 may not be closed up. Since the packings 38 reduce the space formed between the membrane protecting tubes 11 and the casing 13, the generated amount of waste washing water by washing hollow fiber membrane elements 6 is sharply decreased, thereby increasing a water recovery rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation device, and more particularly to a solid-liquid separation device used in fields such as water purification treatment, sewage treatment, and wastewater treatment.

[0002]

2. Description of the Related Art The filtration and washing in a solid-liquid separation device 1 will be described with reference to FIG. Filtration chamber 3 from raw water inlet 2
The raw water containing the suspended substance flowing into the inside is filled in the filtration chamber 3 and filtered by the hollow fiber membrane element 6 in which a number of hollow fiber membranes 5 are bound. The filtered water passes through the hollow fiber membrane element 6 and collects in the water collecting chamber 7, and the filtered water outlet 8
Taken out of If the filtration is continued, suspended matter in the raw water adheres to the hollow fiber membrane element 6 and the filtration performance deteriorates. The cleaning is performed, for example, by sending air from the air pipe port 9 to the water collecting chamber 7 to apply pressure to the inside of the hollow fiber membrane element 6 or from the air ejector 10 to the inside of the membrane protection tube 11 for housing the hollow fiber membrane element 6. Air scrubbing cleaning is performed by blowing air to scrub the hollow fiber membrane element 6, and the suspended substances adhering to the hollow fiber membrane element 6 are separated into raw water. Washing wastewater, which is raw water containing the separated suspended substances, is discharged from the drain pipe 12 to the outside of the casing 13.

[0003]

However, the conventional solid-liquid separation apparatus shown in FIG. 7 generates a large amount of washing wastewater discharged from the drain pipe 12, and the amount of filtered wastewater relative to the raw water supplied into the filtration chamber 3 is large. However, there is a disadvantage that the water recovery rate, which is the yield of water, is deteriorated. Further, since the washing wastewater cannot be discharged to a river or the like as it is, there is a problem that the cleaning wastewater must be discharged after purification treatment.

[0004] From such a background, there has been a demand for a hollow fiber membrane element type solid-liquid separation device capable of reducing the amount of washing wastewater generated. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a solid-liquid separation device that can significantly reduce the amount of washing wastewater generated by washing a hollow fiber membrane element.

[0005]

According to the present invention, in order to achieve the above-mentioned object, the present invention is housed in a tubular membrane protective tube,
A plurality of hollow fiber membrane elements in which a large number of hollow fiber membranes are bound are hung on a communicating portion of a partition plate which horizontally partitions the upper part in the casing, and a filtration chamber is formed below the partition plate and a filter chamber is formed above the partition plate. A water collection chamber for collecting the filtered water filtered by the hollow fiber membrane element is formed, and the raw water flowing into the filtration chamber is filtered by the hollow fiber membrane element, while the hollow fiber membrane element is appropriately washed and washed. In a solid-liquid separation device for discharging washing wastewater from the filtration chamber to the outside of the device, a space between the casing and the membrane protection tube is filled with a filler.

According to the present invention, by filling the space between the casing and the membrane protective tube with a filler, the volume of the filtration chamber is reduced, and the washing wastewater obtained by washing the hollow fiber membrane element which has been often used in the prior art. The amount of water generated can be greatly reduced, thereby increasing the water recovery rate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a solid-liquid separation device according to the present invention will be described below in detail with reference to the accompanying drawings. The same devices and members as those in FIG. 7 described in the related art will be described with the same reference numerals. FIG. 1 is a cross-sectional view showing the overall configuration of the first embodiment of the solid-liquid separation device of the present invention. As shown in FIG. 1, a partition plate 20 that partitions the inside of the casing 13 in a lateral direction is provided above the substantially cylindrical casing 13 of the solid-liquid separation device 50, and below the partition plate 20. A filtration chamber 3 is formed, and a collection chamber 7 for filtered water is formed on the upper side. In the filtration chamber 3, a plurality of hollow fiber membrane elements 6 are provided.

The hollow fiber membrane element 6 is formed by binding a large number of tubular hollow fiber membranes 5 to form a column.
A large number of communicating portions 2 communicating the filtration chamber 3 and the water collecting chamber 7 each having an upper end of the hollow fiber membrane element 6 formed by a partition plate 20.
2 is hung. Thereby, the filtered water filtered by the hollow fiber membrane element 6 is collected in the water collecting chamber 7. This hollow fiber membrane element 6 is housed in a tubular membrane protective tube 11 to prevent breakage and the like, and the upper end of the membrane protective tube 11 is
0, and a plurality of overflow holes 24 are formed in the outer periphery of the upper end of the membrane protection tube 11.

The hollow fiber membrane element 6 in the filtration chamber 3
An air ejector 10 for air scrubbing and cleaning of the hollow fiber membrane element 6 is provided below. The air ejector 10 is formed in a hollow disk shape having an open lower surface, and is connected to a compressor or a blower or the like.
Are provided in the air ejector 10. Further, a plurality of slits 30 are formed on the outer peripheral surface and the inner peripheral surface of the air ejector 10, and a position where each slit 30 is formed and a center position of the membrane protection tube 11 are set to match. I have. Accordingly, when air is supplied from the compressor to the air ejector 10 via the air inflow pipe 26 in a state where the raw water is filled in the filtration chamber 3, the raw water in the air ejector 10 is released by the air pressure by the air pressure. An air bed layer 32 is formed on the upper portion of the air ejector 10 after being expelled from the air ejector 10. The air accumulated in the air bed layer 32 is jetted out uniformly from each slit 30 of the air jetting device 10, rises as bubbles 34 in the raw water, flows into each membrane protection tube 11, and
Each hollow fiber membrane element 6 is scrubbed.

On the side of the lower end of the casing 13,
The raw water inlet 2 through which the raw water containing the suspended substance 18 (see FIG. 3) flows into the filtration chamber 3 is formed, and an air vent pipe 36 is formed on the upper side surface of the filtration chamber 3. The air release pipe 36 is also used for outflow of raw water. In addition, a filtered water outlet 8 is formed in the upper part of the water collecting chamber 7, and an air piping port 9 for supplying air to the water collecting chamber 7 and removing air therefrom is formed at the lowermost end of the filtering chamber 3. A drain pipe 12 for discharging cleaning wastewater is formed.

A space formed between the membrane protection tube 11 and the casing 13 is filled with a filler 38 so as not to block the overflow hole 24 formed on the upper peripheral surface of the membrane protection tube 11. . The filling material 38 can reduce the space formed between the membrane protection tube 11 and the casing 13 and may be anything as long as it does not dissolve in raw water.
For example, a cylindrical plastic molded body that can be fitted into the casing 13 and formed with a through hole into which the membrane protection tube 11 is inserted may be supported by the casing 13 or suspended from the partition plate 20. In this case, it is preferable to form a gap between the filler 38 and the membrane protection tube 11 to such an extent that the membrane protection tube 11 can be pulled out for maintenance of the hollow fiber membrane element 6 and the like. Alternatively, the membrane protection tube 11
The space formed between the membrane protection tube 11 and the casing 13 may be filled by inflating a rubber bag formed so as to secure an insertion path through which the air is inserted with air. In this case, it is only necessary to bleed the air from the rubber bag when pulling out the membrane protection tube 11 for maintenance of the hollow fiber membrane element 6 or the like, so there is no need to form a gap between the membrane protection tube 11 and the filler 38. . Further, the pipe pipe 42 into which the membrane protection tube 11 is inserted is supported by a pair of upper and lower support plates 44 and 46, and a plastic drum-like filling 38 (see FIG. 5) may be fitted into the casing 13 as shown in FIG. In this case, since the inside of the filler 38 is hollow, the weight is lighter than the plastic molded body, and it can be structurally stronger than the rubber bag.

Next, the operation of the solid-liquid separator 50 configured as described above will be described. Solid-liquid separation device 5 of the present invention
In the case of filtering the raw water containing the suspended substance 18 at 0, the raw water inlet 2 and the filtered water outlet 8 are opened, and the raw water flows in from the raw water inlet 2. Raw water flows into the hollow fiber membrane element 6 from the lower end of each membrane protection tube 11. And
The suspended substance 18 is filtered by each hollow fiber membrane element 6,
The filtered water is collected in the collecting chamber 7 and taken out from the filtered water outlet 8. At the same time, the air vent pipe 36 is also opened, so that a part of the raw water can be taken out from the air vent pipe 36, and the raw water can be circulated and filtered through the raw water inlet 2 into the inflow raw water.

Since the suspended substance 18 adheres to the surface of the hollow fiber membrane 5 due to the continuation of the filtration, the filtration is interrupted periodically and the next washing operation is performed. First, with the solid-liquid separator 50 filled with water, the raw water inlet 2 and the filtered water outlet 8 are closed, and the air inlet pipe 26 and the air vent pipe 36 are opened to allow air to flow from the air inlet pipe 26. When the air flows in, the water in the air ejector 10 first flows out of the lower portion of the air ejector 10 and the slit 30 due to the pressure, and an air bed layer 32 is formed in the air ejector 10 as shown in FIG.
Air is ejected from the slit 30 through the air bed layer 32. By forming such an air bed layer 32, the amount of air ejected from each slit 30 can be made uniform. The air that has been blown out of the air blower 10 rises as bubbles 34 in the water. Each slit 30
Since the hollow fiber membrane element 6 is located just above the air bubbles 34, the air bubbles 34 flow into the respective hollow fiber membrane elements 6 from the lower ends of the respective membrane protection tubes 11, and scrub the hollow fiber membrane elements 6 to form the hollow fibers. The suspended substance 18 adhering to the surface of the thread film 5 is peeled into raw water. Then, the bubbles 34 flow out of the membrane protection tube 11 from the overflow holes 24 provided on the upper side surface of each membrane protection tube 11, and are discharged out of the casing 13 through the air vent tube 36.

After the completion of the air scrubbing cleaning, air is introduced from the air piping port 9 with the air inlet pipe 26 closed and the air vent pipe 36 opened, and the pressure of the filtered water existing in the water collecting chamber 7 is increased. Is flowed back to each hollow fiber membrane element 6 via the communication part 22. After the backflow step is completed, the air pipe port 9 is closed, the drain pipe 12 is opened with the air vent pipe 36 opened, and the washing wastewater that is the raw water containing the suspended solids 18 present in the filtration chamber 3 is drained. Discharge from 12 Further, a back washing step may be performed before the air scrubbing washing.

In the washing operation, according to the solid-liquid separation device 50 of the present invention, the space between the casing 13 and the membrane protection tube 11 is filled with the filler 38, so that the amount of washing wastewater generated can be reduced. it can. Depending on the size of the space between the casing 13 and the membrane protection tube 11 depending on the number of hollow fiber membrane elements 6 housed in the casing 13, the amount of washing wastewater generated by the solid-liquid separation device 50 of the present invention is: This is about 30% to 70% of that of the conventional solid-liquid separation device 1, which is a significant reduction. Thereby, the water recovery rate can be improved, and the amount of treatment for purifying the washing wastewater can be reduced.

According to the solid-liquid separation device 50 of the present invention,
The space between the casing 13 and the membrane protection tube 11 is filled with a filler 38.
Buried in the bubble 34 from the air ejector 10
The bubbles 34 that have not entered the membrane protection tube 11 are filled 3
8 collides with the lower end and a part thereof flows into the membrane protection tube 11. Therefore, unlike the conventional solid-liquid separation device 1, the bubbles 34 that have not entered the membrane protection tube 11 rise in the space between the casing 13 and the membrane protection tube 11 and are wastefully discharged from the air vent tube 36. Therefore, the air bubbles 34 from the air ejector 10 can be effectively used for cleaning the hollow fiber membrane element 6.

After the above three cleaning operations of air scrubbing, backflow, and drainage are completed, filtration is performed again. In this case, first, the raw water inlet 2 and the air vent pipe 36 are opened to open the raw water inlet. 2, raw air flows into the filtration chamber 3, discharges air existing in the filtration chamber 3 from the air release pipe 36, then closes the air release pipe 36, opens the air pipe port 9, and removes air existing in the water collection chamber 7. After discharging from the pipe port 9 and filling the inside of the casing 13 with water, the air pipe port 9 and the air vent pipe 36 are closed, the filtered water outlet 8 is opened, and the above-described filtration is restarted.

FIG. 2 is a sectional view for explaining a second embodiment of the solid-liquid separation device of the present invention. The difference between the second embodiment and the first embodiment is that the lower end of the filler 38 is formed so as to form a space extending from the lower end of the membrane protection tube 11 into a trumpet tube. . According to the second embodiment, the bubbles 34 ejected from the slits 30 of the air ejector 10 are, as shown in FIG.
And collected in each membrane protection tube 11. Therefore,
All the bubbles 34 contribute to the separation of the suspended substance 18, and the bubbles 34 can be used more effectively for cleaning than in the first embodiment. Therefore, a high separation effect can be obtained with less air.

FIG. 4 is a sectional view for explaining a third embodiment of the solid-liquid separation device of the present invention. The difference between the third embodiment and the first embodiment is that the upper surface of the air ejector 10 is bonded to the lower end of the filling 38. According to the third embodiment, the position of the slit 30 of the air ejector 10 is set immediately below the hollow fiber membrane element 6 before the air ejector 10 is placed in the casing 13.
Can be installed, so that the air ejector 10 can be easily installed.

[0020]

As described above, according to the solid-liquid separation device of the present invention, since the volume of the filtration chamber is reduced by the packing material, the generation of the washing wastewater that has been used to wash the hollow fiber membrane elements is large in the prior art. This has the effect of greatly reducing the amount, thereby increasing the water recovery rate, and reducing the amount of treatment for purifying the washing wastewater.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of a solid-liquid separation device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the overall configuration of a second embodiment of the solid-liquid separation device of the present invention.

FIG. 3 is a diagram illustrating a second embodiment, illustrating a state in which bubbles are ejected from an air ejector and guided to a hollow fiber membrane element.

FIG. 4 is a cross-sectional view illustrating an overall configuration of a solid-liquid separation device according to a third embodiment of the present invention.

FIG. 5 is a view for explaining the configuration of a specific example of the packing material of the first embodiment in the solid-liquid separation device of the present invention.

FIG. 6 is a cross-sectional view illustrating the overall configuration of the solid-liquid separation device according to the first embodiment of the present invention in which the packing of FIG. 5 is used.

FIG. 7 is a cross-sectional view showing the overall configuration of a conventional solid-liquid separation device.

[Explanation of symbols]

2 Raw water inlet 3 Filtration chamber 5 Hollow fiber membrane 6
... hollow fiber membrane element 7 ... water collecting chamber 8 ... filtered water outlet 9 ... air piping port
DESCRIPTION OF SYMBOLS 10 ... Air ejector 11 ... Membrane protection tube 12 ... Drain tube 13 ... Casing 18 ... Suspended substance 20 ... Partition plate 26 ... Air inflow tube 36 ... Air release tube 38 ... Filling material 40 ... Wrapper tube part 50 ... Solid-liquid separation apparatus

Claims (2)

[Claims] Claims: 1. While being housed in a tubular membrane protective tube,
A plurality of hollow fiber membrane elements in which a large number of hollow fiber membranes are bound are hung on a communicating portion of a partition plate which horizontally partitions the upper part of the casing, and a filtration chamber is formed below the partition plate and a filter chamber is formed above the partition plate. A water collection chamber for collecting the filtered water filtered by the hollow fiber membrane element is formed, and the raw water flowing into the filtration chamber is filtered by the hollow fiber membrane element, while the hollow fiber membrane element is appropriately washed and washed. A solid-liquid separation device for discharging washing wastewater from the filtration chamber out of the device, wherein a filler is filled in a space between the casing and the membrane protection tube. 2. The solid-liquid separation apparatus according to claim 1, wherein a lower end shape of the filler is formed so as to form a space extending in a trumpet shape from a lower end of the membrane protection tube.