JPS6393307A - Hollow yarn-type filter - Google Patents

Abstract

PURPOSE:To reduce the flow resistance in hollow yarn and to enhance the property of cleaning air by providing a liquid collection chamber for filtrate to one aperture end of a hollow yarn-type filter, partitioning the inside of an outer cylinder into a plurality of spaces with ribs and packing hollow yarn in one part thereof and making the other parts a passage of filtrate. CONSTITUTION:A number of hollow yarns 10 having apertures in both ends are fixed in an outer cylinder 16 with the upper and lower adhesives 4 and a liquid collection chamber 5 of filtrate is provided to the lower end part of a filter by sealing it with a flat packing 9'. The inside of the outer cylinder 16 is partitioned into a plurality of spaces with ribs 11 and one part of these spaces is packed with hollow yarn 10, and the other parts are not packed therewith and used as passages 11' of filtrate collected in the liquid collection chamber 5. By such a way, the flow resistance of hollow yarn can be reduced even in a long-size filter. Further at a time for backwashing the filter, air is collected to a skirt-shaped recessing part 6 for collecting air provided to the lower part of the filter and the air is introduced into the filter through a slit 7 and an introduction hole 8 of air.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a hollow fiber filter using external pressure for removing colloidal substances in a solution.

(Prior art and its problems) Hollow fiber filters are economical because they have a large membrane area per unit volume, and are used in various fields such as semiconductors, medicine, and food. By reducing the diameter of the hollow fibers, the number of membranes packed per unit volume can be increased, but due to the resistance of water flowing through the hollow fibers, hollow fiber filters with a length of about 1 m are usually used. There is. However, recently, in nuclear power plants and the like, there is a tendency to increase the length of hollow fiber filters in order to minimize the installation area. The filter used in nuclear power plants is a suspended type filter with external pressure total filtration.
The lower end of the filter is closed and the filtrate is drawn off to the upper end of the filter. Therefore, as the length of the filter increases,
Due to the resistance of the water flowing inside the hollow fibers, even if the length of the filter is increased, the amount of filtrate hardly increases. Japanese Patent Application Publication 1986-
No. 206405 and JP-A No. 60-244306, a water collection pipe is provided inside a hollow fiber type discharger, both ends of the filter are open, and a filtrate collection chamber is provided at the lower end. It has been proposed to lower the flow resistance inside the hollow fiber membrane by collecting the filtrate that has drained into the water collection chamber at the lower end through a collection pipe at the upper end.

However, after use, the filters used in nuclear power plants
Because it is radioactive, it is necessary to use polyolefin materials such as polyethylene and polypropylene, which can be incinerated and do not generate corrosive gases. When using a polyolefin-based water collection pipe, there is no adhesive to bond it to the polyolefin-based pipe, so it is necessary to provide some kind of sealing mechanism to the water collection pipe, which has the disadvantage of reducing the number of hollow fibers that can be filled into the housing. there were.

The inventors aimed to solve these shortcomings.

In Japanese Patent Application No. 61-93437, by mixing large-diameter hollow fibers and small-diameter hollow fibers, the large-diameter hollow fibers have a filtration function and a liquid collecting function, and the filtrate volume is larger than that in JP-A No. 60-206405. Successfully developed a filter. However, JP-A-61-
In the filter of No. 93437, if the large diameter hollow fibers and the small diameter hollow fibers are made of the same material, the pressure resistance of the large diameter hollow fibers will decrease, and if you try to increase the pressure resistance, the wall thickness of the large diameter hollow fibers will become thicker. However, there was a problem in that the number of large-diameter hollow fibers packed was reduced and the amount of filtrate was not increased as expected.

(Object of the Invention) In order to solve the above-mentioned problems, the object of the present invention is to provide a hollow fiber filter that lowers the flow resistance in the hollow fibers without reducing the membrane area of the hollow fibers, and has good air cleaning performance. is to provide.

(Structure of the Invention) The hollow fiber type filter of the present invention is a hollow fiber type filter in which a large number of hollow fiber membranes are arranged in a substantially straight line inside an outer cylinder, and both ends of the hollow fibers are fixed with an adhesive in an open state. In the filter, a liquid collecting chamber for collecting filtrate is attached to one open end of the filter, and the outer cylinder of the filter is partitioned into a plurality of spaces by ribs, and a part of the space is divided into a plurality of spaces. It is characterized in that it is filled with hollow fibers and the other part is not filled with hollow fibers and is used as a passage for the filtrate collected in the liquid collection chamber.

(Embodiments and Effects) The present invention will be described below with reference to an embodiment shown in the drawings, but the present invention is not limited to this scope.The filter of the present invention, as shown in FIG. A large number of hollow fibers 10 with both ends open are fixed in an outer cylinder 16 with upper and lower adhesives 4, and i! ! A collecting chamber 5 for collecting filtrate is provided at the lower end of the filter and sealed by a flat packing 9'.

Around the liquid collection chamber 5, a skirt-shaped recess 6 is provided with an O-ring 9.
It is provided in the outer cylinder 16 in a sealed manner. The recess 6 has a skirt-like opening at the lower end and is shaped to easily collect air. The collected air enters the filter 3 through the slit 7 and the air inlet 8. Further, as shown in FIG. 2, the outer cylinder 16 has ribs 11 inside and is partitioned into a plurality of spaces. A part of this space is filled with hollow fibers 10, and the other part is not filled with hollow fibers and is used as a passage 11' for the filtrate collected in the liquid collecting chamber 5 at the lower end of the filter. be done. The filtrate passage 11' partitioned by the ribs 11 of the outer cylinder 16 is not particularly limited, as shown in FIG. 2 (L) to (C), and one or more may be provided. The shape may be linear or curved.

The hollow fibers used in the filter of the present invention usually have an inner diameter of 0.1 to
0.8 mm and an outer diameter of about 0.3 to 1.5 mm, and the material is not particularly limited, but considering incineration after use, polyethylene, polypropylene, and cellulose-based hollow fibers are preferable.

FIG. 3 shows an example of the use of the hollow fiber filter of the present invention, I!
! The filter 3 is suspended from the partition plate 2 and held within the pressure vessel 1 . The pressure vessel is provided with an inlet pipe 12 for the liquid to be treated, an outlet pipe 13 for the filtrate, an outlet 14 for discharging metal colloids etc. attached to the hollow fibers, and nozzles 15 and 18 for introducing air into the filter. The liquid to be treated enters the filter through holes 17 provided in the outer cylinder of the filter, is filtered from the outside of the hollow fibers 10, and flows inside the hollow fibers. The filtrate flowing to the lower end of the filter is I! !
The liquid collects in the collection chamber 5 at the lower end of the filter, passes through the filtrate passage 11' partitioned by the ribs 11 of the outer cylinder 16, and is combined with the filtrate flowing to the upper end to exit the system through the discharge pipe 13. being extracted.

When the filtration differential pressure of the hollow fiber filter exceeds a certain pressure, filtration is stopped and backwashing or air scrubbing is performed to remove metal colloids and the like adhering to the hollow fiber membrane. That is, the air introduction nozzle 18 provided in the filtrate extraction pipe 13
Backwashing is performed by introducing more air to push out the filtrate accumulated in a part of the partition plate 2 inside the pressure vessel 1, or by introducing air from the air introduction nozzle 15 provided below the pressure vessel 1 to the lower part of the filter. Air is collected in the skirt-like air collecting recess 6 provided, and the air is caused to pass through the slit 7 and the air introduction hole 8 and rise along the hollow fiber 1O while vibrating the hollow fiber to remove the metal attached to the hollow fiber 10. Air scrubbing is performed to shake off colloids. Metal colloids, etc. that have fallen off from the hollow fibers are taken out from the hole 17 at the bottom of the outer cylinder of the hollow fiber type filter or the air introduction hole 8, and then taken out from the outlet provided at the bottom of the pressure vessel. 1
4. The thread is pulled out from the thread. The filter whose capacity has been restored by cleaning can be used again.

(Effects of the Invention) The hollow fiber filter of the present invention has a filtrate passage not filled with hollow fibers at all in the outer cylinder, so it is possible to lower the flow resistance of the hollow fibers even in the case of a long filter. It is easy to filter. In addition, compared to known filters in which a liquid collecting pipe is passed through the center of the filter, a special sealing mechanism is not required, so molding is easy, the membrane area can be increased, and it is economical.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing one embodiment of the hollow fiber filter of the present invention, and FIG. 2 is an explanatory view showing the shape of the inside of the outer cylinder.
(a), (b), and (c) are each modified examples. Third
The figure is an explanatory diagram showing how the filter is used. 1. Pressure vessel 10. Thin hollow fiber 2, partition plate
11. Rib 3, hollow fiber filter 11', filtrate passage 4, adhesive
12. Liquid to be treated introduction pipe 5, liquid collection chamber
13. Filtrate extraction pipe 6, air gathering recess 14.
Metal colloid exhaust 7, slit outlet 8, air introduction hole 15. Air introduction nozzle 9.0-
Ring 16. Outer cylinder 9', flat backing 17. Hole 18, air introduction nozzle

Claims (1)

[Scope of Claims] 1. A hollow fiber type filter in which a large number of hollow fiber filtration membranes are arranged in a substantially straight line in an outer cylinder, and both ends of the hollow fibers are fixed with an adhesive in an open state. A collection chamber for collecting the filtrate is attached to one open end of the filter, and the outer cylinder of the filter is partitioned into a plurality of spaces by ribs, some of the spaces are filled with hollow fibers, and the outer cylinder of the filter is divided into a plurality of spaces by ribs. A hollow fiber type filter characterized in that a part of the chamber is not filled with hollow fibers and is used as a passage for the filtrate collected in the liquid collection chamber. 2. The hollow fiber filter according to claim 1, wherein a skirt-like recess for collecting air is provided at the lower end of the filter.