JPH0214084B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to leakage testing of a hollow fiber membrane module having a large number of hollow fiber membranes, particularly hydrophilic porous hollow fiber membranes. The present invention relates to a method for testing and a device used for this test.

[Conventional technology]

Conventionally, a large number of hollow fiber membranes are housed in a housing in a loop or in a straight line, and the ends of the hollow fiber membranes are fixed in the housing with resin, and the ends are cut to allow ventilation (or water flow). ) A hollow fiber membrane module for filtering various gases and liquids constituting the end face is known.

A method for testing for leaks in such a hollow fiber membrane module is to apply a predetermined water pressure to the outside of the hollow fiber membrane and check for leaks by checking for the presence or absence of water leaking to the water passing end surface. There is.
However, this testing method is effective only when the hollow fiber membrane is hydrophobic. That is, if the hollow fiber membrane has hydrophilic properties, water will naturally pass through the membrane surface of the hollow fiber membrane, so it cannot be used as a means for leak detection. Furthermore, if the water that has flowed into the module is left as it is after the leakage test, it may cause bacteria to grow in the module or mold to grow in the hollow fibers.
Therefore, it is necessary to dry the module after inspection, but since the hollow fibers are generally compactly packed inside the module, it is not possible to easily dry and remove the water that has flowed in, so it is necessary to dry the module using methods such as vacuum drying. It becomes necessary to dry it by means, which increases the number of steps for inspection and increases the cost.

Therefore, as a leakage inspection method for a module made of a hydrophilic hollow fiber membrane, there is a method in which pressurized air is supplied from the outside of the hollow fiber membrane and the amount of air flowing out from the ventilation (or water passing) end face is measured; Alternatively, a method has been considered in which a predetermined amount of pressurized air is applied to the outside of the hollow fiber membrane, and the presence or absence of leaks is tested based on the drop in pressure. However, when using these methods, a considerable flow rate of air is required to pass through the module, which requires a large pressurizing device, and it is also difficult to detect pinholes in the hollow fiber membrane, for example. If it takes a considerable amount of time to reach a certain amount of air or pressure drop, or if the pinhole is extremely small, it cannot be detected, so it cannot be used as a practical means of leak detection.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a method for inspecting leaks in a hollow fiber membrane module, particularly a hollow fiber membrane module containing a hydrophilic porous hollow fiber membrane, and a device used therefor. It is in.

Another object of the present invention is to provide a leak testing method that can accurately detect even hollow fiber membrane modules with extremely fine pinholes, and a device used therefor.

Another object of the present invention is to provide a leak testing method that does not require troublesome post-processing of modules after testing and can be carried out easily and in an extremely short period of time.

Still another object of the present invention is to provide a leak testing device for hollow fiber membrane modules that has a simple structure and is easy to handle.

[Means for solving problems]

That is, the leak testing method for a hollow fiber membrane module of the present invention involves fixing the ends of a large number of hollow fiber membranes in a housing with a resin while keeping each end open, and at least one vent formed with the resin. In a method for inspecting leaks in a hollow fiber membrane module configured with an end face, vacuum suction is performed from the ventilation end face of the module, and air containing particles of microparticles is drawn from the outer surface side of the hollow fiber membrane. The method is characterized in that the air sucked from the ventilation end face is passed through a particle counter, and the number of microparticles in the sucked air is measured.

Further, in the hollow fiber membrane module leak testing device of the present invention, the ends of the plurality of hollow fiber membranes are each fixed in a housing with a resin while maintaining an open state, and at least one vent formed with the resin is provided. A device for inspecting leaks in a hollow fiber membrane module configured with an end surface, comprising a module mounting member that can airtightly grip the ventilation end surface of the hollow fiber membrane module, and a suction function,
It has a particle counter for measuring the number of microparticles in the air, a suction means, and a filter, and a first valve is provided between the ventilation end face gripping part of the module of the mounting member and the particle counter. The suction means and the filter are connected via valves, respectively, between the fitting member of the piping and the first valve, and between the first valve and the particle counter. .

[Preferred mode for carrying out the invention]

First, the hollow fiber membrane module that is the subject of the leak test of the present invention will be briefly explained.

FIG. 1 is a side sectional view showing an example of a hollow fiber membrane module. A large number of hollow fiber membranes 2 housed in a housing 1 are bundled into a loop shape (U-shape), and both ends of each are fixed such that a resin 3 covers the space between the hollow fiber membranes. A plan view of the ventilation end surface A in FIG. 1 is shown in FIG. 2. In FIG. 2, the hollow fiber membrane 2 is cut along with the fixing resin 3 at this end face to have an open end, forming a ventilation end face A, and the resin 3 is placed between each hollow fiber membrane 2. Filled and sealed airtight.

FIG. 3 is a partially cutaway side view showing another example of the hollow fiber membrane module. In this example, a large number of hollow fiber membranes 2 are housed linearly in a housing 1 having an opening 4, and both ends thereof are fixed with resins 3, 3' while forming open ends. A water collection chamber 5 is provided on one ventilation end surface A', and the two ventilation end surfaces A and A' are connected by a filtrate pipe 6 passing through the center of the module.

The hollow fiber membranes 2 constituting these hollow fiber membrane modules may be hydrophobic or hydrophilic, and may be homogeneous or porous. However, in the case of hydrophilic porous membranes, since no suitable leakage testing method has been established, the method and apparatus of the present invention can be particularly suitably applied.

Hereinafter, the method for inspecting leaks in a hollow fiber membrane module of the present invention will be described in more detail with reference to the drawings.

To perform a leak test on a microporous hollow fiber membrane module having the structure shown in FIG. 1 based on the method of the present invention, first, vacuum suction is performed from the end surface A using a suction means such as a vacuum pump. Air is sucked in from the other end B of the housing as shown by the arrow. The sucked air reaches the hollow portion of the hollow fiber from the outer surface of the hollow fiber membrane 2 through the fine pores of the membrane, and is further sucked toward the end surface A. At this time, microparticles such as dust contained in the air are filtered by the micropores on the membrane surface of the hollow fiber membrane 2, and microparticles larger than the diameter of the micropores are blocked, and only clean air flows through the end surface A. more attracted. However, if the hollow fiber membrane 2 has pinholes or broken parts, air containing dust is sucked from the end surface A through these pinholes or broken parts. In addition, when there is a gap between the resin 3 and the hollow fiber membrane 2, or when there is a minute ventilation hole (also called a cavity) in the resin 3 that communicates from the top surface to the bottom surface of the resin layer, etc. Similarly, dust-laden air is sucked through these gaps and vents.

When the air sucked from end face A is guided to the particle counter in this way, if there is a leak and the sucked air contains dust, the particle counter measures the number of dust particles of various particle sizes. Ru. On the other hand, if there is no leakage, the number of microparticles measured by the particle counter is only particles with a particle size that can pass through the micropores of the hollow fiber membrane. If the particle size is sufficiently small, only microparticles smaller than the detection sensitivity of the particle counter will be sucked in, so the number of particles measured will be zero. Therefore, whether or not a leak has occurred in the hollow fiber module can be easily determined based on the count number of the particle counter.

The method of the present invention also applies to the hollow fiber membrane module shown in FIG. 3 and modules of other aspects, in the same manner as in the above case, by causing air sucked from the ventilation end face to pass through a particle counter,
This can be done by measuring the number of particles contained in the suction air.

As the particle counter used in the method of the present invention, a commercially available particle counter that is normally used to measure the cleanliness of a clean room can sufficiently perform its function. In addition, the air containing microparticles to be used for inspection may be one whose particle size and number are adjusted appropriately according to the pore size of the membrane to be measured. It is convenient to use normal air as it is, since it contains a large amount of particle-sized dust.

In the inspection method of the present invention, a suction air amount of about 5 to 10 is sufficient to determine whether there is a leak in the module. In modules where the micropores of the hollow fiber membrane are sufficiently small, dust that can be detected by a particle counter will be mixed into the suction air only when a leak exists, so it can be detected instantly.

Next, the leak testing device for a hollow fiber membrane module of the present invention will be described in more detail with reference to FIG. 4, which is shown as an example thereof.

The leak testing device of the present invention basically includes a module mounting member 7, a particle counter 8, a suction pump 9, and a filter 10.

The hollow fiber membrane module used for leak testing is
It is fixed to the module mounting member 7. In this device, the module attachment member 7 is attached to a holder 1 that grips the ventilation end surface A of the hollow fiber membrane module.
1, and a fixture 14 having an intake port 12 and integrated with a holding mechanism 13. The ventilation end surface A of the module is completely isolated from the outside air by the action of an O-ring 15 provided on the holder 11. The particle counter 8, which has a built-in gripping part on the module opening end surface of the holder 11 and a suction means, is connected to the pipes 17 and 1 through the first valve 16.
8. A suction pump 9 is installed in the middle of the pipe 17 connecting the holder 11 and the first valve 16.
However, a filter 10 for air filtration is connected in the middle of the pipe 18 connecting the first valve 16 and the particle counter 8 via valves 19 and 20, respectively.

In order to inspect the hollow fiber membrane module for leaks using this device, first close the first valve 16 while holding the hollow fiber membrane module with the holder 11 and pressing it with the fixture 14, and then close the first valve 16. When the module is opened and the suction pump 9 and the suction means built into the particle counter 8 are activated, on the module fixed side, the outside air flows from the intake port 12 of the fixture 14 through the module, passes through the piping 17 and the valve 19, and then enters the suction pump. Exhausted at 9. On the other hand, on the particle counter side, air filtered by a filter 10 is guided to the particle counter 8 through a valve 20 and a pipe 18. By continuing this operation for a predetermined period of time, the space in the holder 11 and the inside of the pipe 17 are replaced with air filtered by the hollow fiber membrane module, and the path inside the pipe 18 and the particle counter 8 is replaced by the filter 10. Cleaned with filtered air. At this time, if a filter with the same membrane area and pore diameter as the hollow fiber membrane module used for leak inspection is used, and the particle counter 8 is activated,
Compensatory particle counts can be measured for leak-free hollow fiber membrane modules to be tested. After carrying out the preparatory operation of the leak inspection device in this way, the valve 19,
20 is closed and the first valve 16 is opened to allow the particle counter 8 to suck in the required amount of air filtered by the module.The particle counter 8 measures the amount of dust in the filtered air and detects leakage. Inspections will be carried out. After the measurement is completed, the first valve 16 is closed, the holding mechanism 13 is activated to remove the fixture 14, and the module is removed from the holder 11, thereby completing the series of leak test operations.

〔Effect of the invention〕

As detailed above, according to the method of the present invention,
It is possible to very easily inspect the presence or absence of minute pinholes in a hollow fiber membrane module without affecting the module to be inspected, and this has a great effect on quality control.

Furthermore, by using the inspection device of the present invention, leak inspection of hollow fiber membrane modules can be carried out efficiently in a short period of time. Inspections can also be carried out with ease.

〔Example〕

In the following, the method and apparatus of the present invention will be explained in more detail according to specific examples.

Example 1 The hollow fiber membrane module used for leak testing was made by bundling 1440 polyethylene hollow fibers EHF (manufactured by Mitsubishi Rayon Co., Ltd.) into a loop so that the total surface area of the hollow fibers was 0.6 ^m2 . It has a structure as shown in FIG. 1, in which the open end surfaces of hollow fibers are potted with polyurethane.

The device used for leak testing has the structure shown in Figure 2, and includes a holding mechanism, a valve,
A commercially available air cylinder, a suction electrode valve, and a vacuum pump were used as the suction pumps. The filter is made using the same hollow fiber used in the module used for the inspection, and the particle counter is made by Rion Corporation, which measures the cleanliness of indoor air ( KC-13) was used.

Using this device, after activating the suction pump and the suction means built into the particle counter and carrying out the preparatory operation described above for 1 minute, the air that had passed through about 10 hollow fiber modules was guided to the particle counter. . The number of counts was 0 when the detection sensitivity was set to a particle size of 0.3 μm. On the other hand, in a leak test for a hollow fiber module in which one pinhole was intentionally created in one hollow fiber using a needle using a similar operation, the particle counter counted 10, indicating the presence of a leak. was confirmed.

The time required for the leak test for one module was approximately 3 minutes, including the time for installing and removing the module.

[Brief explanation of drawings]

FIG. 1 shows a side sectional view of one embodiment of the hollow fiber membrane module to be subjected to the leak test of the present invention, and FIG. 2 shows a plan view of the ventilation end surface A thereof. FIG. 3 is a partially cutaway side view showing another example of the hollow fiber membrane module. FIG. 4 is a schematic diagram showing an example of a leak testing device for a hollow fiber membrane module of the present invention. 1: Housing, 2: Hollow fiber membrane, 3: Fixing resin, 4: Opening, 5: Water collection chamber, 6: Filtration piping, A:
Ventilation end face, B: Other end of housing, 7: Module mounting member, 8: Particle counter,
9: Suction pump, 10: Filter, 11: Holder, 12: Intake port, 13: Holding mechanism, 14:
Fixture, 15: O-ring, 16: First valve, 1
7, 18: Piping, 19, 20: Valve.

Claims (1)

[Scope of Claims] 1 The ends of a large number of hollow fiber membranes are each fixed in a housing with a resin while maintaining an open state, and have at least one ventilation end surface formed of the resin. In a method for inspecting leaks in a hollow fiber membrane module, vacuum suction is performed from the ventilation end face of the module, air containing particles of microparticles is introduced from the outer surface of the hollow fiber membrane, and air is sucked from the ventilation end face. 1. A leak testing method for a hollow fiber membrane module, comprising: passing the drawn air through a particle counter, and measuring the number of microparticles in the sucked air. 2. Leakage of a hollow fiber membrane module configured in which the ends of a large number of hollow fiber membranes each remain open and are fixed in a housing with a resin, and have at least one ventilation end surface formed of the resin. It is a device for inspecting air flow, which includes a module mounting member that can airtightly grip the ventilation end face of a hollow fiber membrane module, a particle counter that has a suction function and measures the number of microparticles in the air. , a suction means, and a filter, the ventilation end face gripping portion of the module of the mounting member and the particle counter are connected by a pipe having a first valve in the middle thereof, and the suction means and the filter each have a suction means and a filter. A leak testing device connected via a valve between the piping attachment member and the first valve and between the first valve and the particle counter.