JPH067782Y2 - Fluororesin based porous filter - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] The present invention relates to the invention of a fluororesin-based porous filter, in which the durability is remarkably improved, and an attempt is made to obtain a filter capable of performing highly accurate filtering action. It is a thing.

Industrial application fields Filters for filtering various liquids or gases in the semiconductor and plating industries.

2. Description of the Related Art The use of a fluororesin-based porous film having excellent chemical resistance for filtering various liquids or gases has been conventionally practiced in various ways. That is, a typical example of such a conventional technique is as shown in FIGS. 8 to 12, and is as follows.

A porous fluororesin film such as polytetrafluoroethylene is used as a pleated member having a fold 21 as shown in FIG. 8 or as a case together with a holder with the film piece 28 as shown in FIG. Inserted and used as a cartridge filter.

As shown in FIG. 10, the porous film 20 is held between the inner and outer pipes 23 and 24 in which the through holes 22 are arranged.

Fluororesin-based porous tube 2 as shown in FIG.
As shown in FIG. 5 or FIG. 12, the tube 25 is covered with a fluororesin film 26 in a tubular shape, and the outer surface is covered with a fluororesin cloth 27 in a tubular shape.

Problems to be Solved by the Invention In the above, since the liquid is directly filtered by the porous film, clogging occurs when filtering the high-concentration liquid, the liquid containing coarse particles, etc. Often needed.

Further, in any of the above items 1 to 4, the liquid comes into contact with the film, so that the film is damaged when the liquid contains a metal having sharp corners. However, the conventional equipment that has been generally used as such filtration equipment is an external installation in which the filtrate taken out from the tank or tank to be used is filtered with a filter module and then returned to the tank or tank to be used. Since the mold cartridge filter is mostly used and the liquid to be treated flows out of the tank due to the breakage of the film as described above, a serious accident occurs, so that the cost of equipment for preventing it becomes very high.

The size of a single tube is 0.4μ
It is difficult to capture fine particles of m or less.

If the film breaks, the whole thing must be replaced.

"Structure of device" Means for solving the problem A coating layer of a fluororesin porous film is formed on the outside of a fluororesin porous inner tube, and a fluororesin porous outer tube is further formed on the outer surface of the coating layer. A fluororesin-based porous filter characterized by being covered with.

Action The fluororesin-based porous film sufficiently improves filtration accuracy due to its fine porous structure.

The fluororesin-based porous tube formed on the inner and outer surfaces of the film protects the film, functions as a prefilter, and effectively acts as a backup member for the film. That is, the coarse particles mixed in the fluid to be filtered are filtered out in advance to perform highly accurate filtration with a film, and the film is backed up to perform filtration under a considerably high pressure condition in a stable manner. Of course, it prevents damage to the film due to sharp particles.

EXAMPLE A specific embodiment of the present invention as described above will be described with reference to the accompanying drawings. As shown in FIG. 1, the polytetrafluoroethylene porous inner tube 2 is provided outside the polytetrafluoroethylene porous inner tube 2. The porous film 1 is laminated, and the outer side of the porous film 1 is further covered with a porous outer tube 3 of polytetrafluoroethylene. That is, even with the same polytetrafluoroethylene, the pore size obtained when it is stretched to make it porous is relatively large in the case of tube molding, and the strength of the fibrillated structure stretches in a plane. It tends to be higher than the film obtained by the above method, and the porous film 1 having a minute pore size is held between the inner and outer tubes 2 and 3.

The use state of the filter of the present invention is as shown in FIGS. 2 to 6, and both ends are attached to the outlet 11 portion provided in the filter body inlet body 10 as shown in FIG. , The tank 8 is obtained as shown in FIG.
It is connected to a pump 6 inside, and the liquid in the tank 8 is pressed into the body 10 by the pump 6 and filtered by the filter 5 provided. Further, FIG. 6 shows a use state as a filter shower, in which the fluid pumped by the pump 6 provided in the tank 8 is dropped by the filter 5 and the conveyor 1
8 Drop onto the product to be transferred.

In the above-mentioned embodiment, the case where the fluid is press-fitted into the filter 5 of the present invention in the form of a pipe for filtration is shown. For example, it does not prevent the perforated pipe 23 as shown in FIG. 10 or a pipe made of a net material from being incorporated and connected to the suction side of the pump 6 for use in filtration.

As a specific production example, the outer diameter is 5.6 mm, the inner diameter is 5.0 mm, the inner diameter of the porous tube is 3.5 μm, and the perforation rate is 70%. Is 0.1
A tubular film (outer diameter: 6.m) having a porosity of 85% and a polytetrafluoroethylene film 1 having a porosity of 85% was heat-fused at 450 ° C. for 50 seconds under a pressure of 0.5 kg / cm ² .
0 mm, inner diameter 5.9 mm) Tube 2 with 1 cm on each end
Then, an outer tube (outer diameter 7.0 mm, inner diameter 6.4 mm) having the same structure as the above-mentioned tube 2 was put on the outer side of the thus obtained one with both ends aligned with the inner tube 2. I got this 1m long filter,
This was cut out from a polytetrafluoroethylene square rod and attached to the outlet 11 portion of the filter body inlet body 10 as shown in FIG. 2 with both ends inserted as shown in FIG. 3, and a heat-shrinkable tube (made of PFA, long The effective fixed range is 6.0-9.0 at 20mm.
mm) and heat-shrinked and fixed as shown in FIG. On the opposite side of the inlet 12 of the filter inlet body 10
An air vent hole 13 of 0.5 mmφ was attached as shown in FIG. 3, one end of the heat-shrinkable tube 9 was fixed by heating, and the other end was connected to the suction port of the pump 6 as shown in FIG.

That is, the filter body flows from the pump to the filter, and the air is removed from the air removal and does not stay inside the filter.
The following table shows the performance of this production and the filter module shown in Fig. 4.

"Effects of the device" According to the present invention as described above, the film with high filtration accuracy is properly protected and integrated by the inner and outer porous tubes, and it also functions as a pre-filter and a backup layer to prevent clogging. Preventing effectiveness and improving pressure resistance in the film layer, as a result of which efficient filtration treatment is performed, and its durability is improved to several tens of times that of conventional products. Of course, all are fluororesin-based. It is a device that has a great effect industrially because it has stable chemical resistance.

[Brief description of drawings]

The drawings show the technical contents of the present invention. FIG. 1 is a perspective view of a partially cut end of the present invention, and FIG.
The figure is a perspective view of the filter body inlet body to which this product is applied.
The figure is a perspective view showing a state in which the product of the present invention is attached to it, and FIG.
Each of the figures is an explanatory view showing another usage mode of the product of the present invention, FIG. 7 is a sectional view of the product of the present invention in a state of being attached to an inlet portion, and FIGS. 8 to 12 are oblique views of a conventional filter medium, First
FIG. 3 and FIG. 14 are explanatory views showing the utilization state. However, in these drawings, 1 is a fluororesin porous film, 2 is a fluororesin porous inner tube, 3 is a fluororesin porous outer tube, 5 is a filter, 6 is a pump, 8 is a tank, 9 is heat. A shrinkable tube, 10 is a filter body inlet body, and 11 is an outlet.

Claims (1)

[Scope of utility model registration request] 1. A coating layer of a fluororesin porous film is formed on the outside of a fluororesin porous inner tube, and a fluororesin porous outer tube is further covered on the outer surface of the coating layer. Fluororesin-based porous filter.