JPH04150928A - Filtering mechanism - Google Patents

Abstract

PURPOSE:To permit a large amt. of fluid to be filtered smoothly and stably by a method wherein a plate-like filter medium is provided in a housing in such a manner as to allow for its deformation or displacement which may take place under the condition restrained by the housing in passing the fluid to be treated. CONSTITUTION:A plate-like filter medium 1 in a housing 2 is provided with a means for controlling its deformation or displacement under the condition of passing the fluid to be treated allowing for at least one of the fixing of the periphery of the filter medium 1 to the housing 2, the attachment of the plate-like folded corners to the inner surface of the housing, the mutual interference between the folded pleats and the provision of the auxiliary material such as spacer or net. As a result, this method permits the passage of the fluid to be treated under so a high pressure as to exceed the limitation imposed on the conventional filter of this kind and a smooth and stable filtering of a large amt. of fluid can be effected through such a compact equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION The present invention relates to the creation of a filtration mechanism, and an object thereof is to provide a filtration mechanism that is compact in structure and capable of performing highly efficient filtration processing.

Industrial applications A mechanism for filtering liquids, etc.

(Prior Art) It has been common practice to employ a porous synthetic resin membrane in a filtration mechanism, and in this case, the porous synthetic resin membrane material is pleated to increase the filtration area. Various proposals have also been made regarding the use of . In other words, the adoption of a porous synthetic resin membrane having a pore size that matches the purpose of filtration, and in particular the use of a pleated fluororesin porous membrane with excellent chemical resistance, is also disclosed in JP-A-61-1492.
No. 19 and the same No. 149220 have been proposed.

In other words, a filtration material is used in which a sand-inch sheet made of a fluororesin filter membrane and a thermoplastic fluororesin net support layered on both sides is folded into a cylindrical shape by pleating, and the edges on both sides are fused in a liquid-tight manner. A thermoplastic fluororesin is infiltrated between the pleat end folds and sealed and fused, or a corrosion-resistant metal camp is provided that is liquid-tightly fused to such an end seal.

(Problem to be Solved by the Invention!!I) In the conventional filtration mechanism as described above, the filtration efficiency of the filtration membrane is determined by the liquid flow rate per unit time, and it is important to increase this throughput. That is, since the pore size governs the filtration accuracy, using a membrane material with a small pore size of, for example, 1 μm or less, particularly 0.1 to 0.2 μm,
Although high flow rate processing is attempted to be achieved, implementing high flow rate processing using membrane materials with small pores in this way increases the pressure between both sides of the filtration membrane, that is, between the processing liquid supply side and the discharge side. The difference becomes large and the structure of the filtration membrane itself is destroyed. That is, when the pressure difference becomes large in this way, the pore diameter in the filtration membrane expands, causing pinholes, tears, failure to tear, and rupture. In particular, in the case of micropores with a pore diameter of around 0.1 μm or less, although the filtration accuracy is high, the tissue is delicate and is likely to be damaged or altered by the fluid pressure passing through it.

Therefore, in order to avoid such destruction of the filtration tissue, reinforcing materials are used, or a composite structure with two or three layers of filtration materials is used, but even with these methods, there is a limit to the reinforcement, and the pressure difference There is a limit to the pressure difference that can be used because tissue damage is unavoidable when the temperature rises. Furthermore, pressure loss may also be large depending on the material structure of the reinforcing material.

In addition, in the above-mentioned conventional filters, it is essential to cross the filter media surfaces to allow the filtrate to pass through. Therefore, the filter media is set perpendicular to the flow direction of the filtrate, and the above-mentioned pleated method is adopted. Even in this case, the filtration device has to be quite large because a certain amount of space is left between the formed folds to facilitate the flow perpendicular to the surface of the filter medium. That is, in order to increase the throughput of filtration, since there is no choice but to limit the pressure difference as described above, it is essential to increase the size of the apparatus provided with the filter medium as described above.

The large-sized filtration equipment as described above is expensive and requires a large space for installation, which is disadvantageous in terms of operation.

Furthermore, when a porous resin membrane is used to form a pleated filter medium, the height of the folds is substantially limited to about 10 m, and this point is also subject to design and filtration processing limitations.

"Structure of the Invention" (Means for Solving the Problems) The present invention was developed after consideration to solve the problems in the conventional techniques as described above, and is as follows.

(1) A filtration mechanism characterized in that a pleated filter medium is set in a housing under conditions such that deformation and displacement under conditions of flow of a fluid to be treated are suppressed by the housing.

(2) In order to suppress the deformation and displacement of the pleated filter medium in the housing under the flow conditions of the fluid to be treated, the peripheral side of the filter medium is fixed to the housing, and the pleated bent corners are joined on the inner surface of the housing. A filtration mechanism characterized by one or more of the following: condition, mutual interference of bent parts, and provision of auxiliary materials such as spacers and nets.

(3) Claim characterized in that the peripheral side of the filter medium is sandwiched and tightened between the housing body and the cover body to seal the gap between the housing body and the cover body and fix the filter medium to the housing. The filtration mechanism according to any one of 1.2.

The permeation pressure of the fluid to be treated is increased by setting the pleated filter medium in the working housing under conditions in which deformation and displacement under the flow conditions of the fluid to be treated are suppressed by the housing. Prevents damage to the filter medium and performance deterioration due to permeation of the fluid to be treated. Therefore, its characteristics can be effectively exhibited even in those that perform high-precision filtration using a fine structure.

In order to suppress the deformation and displacement of the filter medium pleated in the housing under the flow conditions of the fluid to be treated, the peripheral side of the filter medium is fixed to the housing, the pleat-shaped bent corners are bonded to the inner surface of the housing, and folded. By using one or more of the mutual interference of curved packing parts and the provision of auxiliary materials such as spacers and nets, it is possible to provide equipment that meets the passage conditions of each fluid to be treated, and it is also possible to replace the filter media. , making updates easy.

The above-mentioned filter material also acts as a sealing material by being inserted and tightened between the housing body and the cover body.In other words, the filter material alone or in combination with other sealing materials can be used to create an accurate pressure seal. Attachment inside the housing and sealing between the housing body and the cover body.

(Example) To explain specific embodiments of the present invention as described above as shown in the attached drawings, in the present invention, a porous membrane obtained by stretching a polytetrafluoroethylene sheet is used as a filter material. The method of employing the filter material 1 as a pleat shape is the same as the conventional method described above, and the filter material 1 is alternately bent 1a to form a pleated shape as shown in FIG. The material 5 is used in the housing 2 under conditions in which deformation or displacement under the flow conditions of the fluid to be treated is suppressed, and for this purpose, an auxiliary material 5 having appropriate elasticity may be added. can.

That is, in the case shown in FIG.
As shown in the figure, a liquid or other fluid to be treated inlet 3 is provided, and the other surface of the housing 2 is provided with an outlet hole 4 for fluid to be treated.
The filter medium 1 inserted into the housing 2 is alternately bent in a pleat shape, and the entire circumference of the filter medium 1 is formed between the base body 2a and the cover body 2b of the housing 2. The bent corners 1a, which are sandwiched between the filter medium 1 and the filter medium 1 to form a pleated shape, are provided in a bonded state to the bottom surface of the base body 2a or the inner surface of the cover 2b.

The stretched porous membrane of polytetrafluoroethylene described above acts as a sealing material by itself being compressed, and together with the filtering medium 1 itself or other sealing material 6, the substrate 2
The filter medium 1 is interposed between the filter medium 1 and the cover 2b and pressurized, thereby acting as an effective sealing material and preventing leakage of the fluid to be treated. As shown in FIG. 1, the folding angle of the pleat-like shape is set in contact with the inner surface of the housing 2 as described above, so that even when the fluid to be treated flows through the filter medium under a certain high pressure condition, the filter material 1 is set to a suppressed state in which it is not substantially deformed or displaced.

In implementing the present invention, if the filter medium 1 is more flexible or the fluid to be treated is permeated under higher pressure conditions (pressure difference conditions), it may be folded alternately into pleats as described above. The folds of the bent filter medium 1 are brought closer to each other as shown in FIG. 2, and when the fluid to be treated flows, the folded folds interfere with each other, and the pleat structure is also deformed by the flow and permeation of the fluid to be treated. , it is possible to avoid displacement.

The pores in the fibrillated structure obtained by stretching the filter medium 1 are obtained when fibrillation progresses to fineness, and are made fine to 0.1 to 0.2 μm or less, thereby improving filtration accuracy. However, at the same time, its fine structure is easily damaged by the pressure of the fluid to be processed passing through it, and its performance is likely to fluctuate. This damage will be prevented and there will be no change in performance.

Furthermore, if necessary, an auxiliary material 5 such as a spacer or a net can be used as an auxiliary material, as shown in FIG. 3, to suppress displacement and deformation of the filter medium 1 during permeation of the fluid to be treated.
It is preferable not to use welding or adhesive to fix the housing 2 to the housing 2 from the viewpoint of man-hours and replacement of the filter medium.

A specific manufacturing example of the product according to the present invention will be described below.

Production Example 1 A porous polytetrafluoroethylene membrane having a thickness of 60 μm, a maximum pore diameter of 0.2 μm, and stretched to have a porosity of 75% was used as a filter medium, and the filter medium was bent alternately to a height of 25 mm. The pleated body is set in the housing 2 as shown in FIG. 2, the bent corners are joined to the inner surface of the housing 2, and the entire circumference of the filter medium 1 is sandwiched between the base 2a and the cover 2b. A filter mechanism with an internal volume of 675 cc that was tightened together with the included sealing material 3 was manufactured.

The liquid to be treated is passed through the filter mechanism obtained as described above at a pressure of 2.5 kg/d for filtration, and as a result, smooth filtration can be carried out, and the condition of the filter medium can be checked after the treatment. After examination, it was confirmed that there was almost no change and that the filtration process could be carried out smoothly. The filtration throughput is 601 in the processing mechanism! /#Iin.

On the other hand, a filtration mechanism was prepared by bending the porous polytetrafluoroethylene filter material formed into a pleat shape to a height of 1.2 mm, and using a filtration mechanism in which the material was formed into a cylindrical shape with a diameter of 75 m, as described above. If the same liquid to be treated is fed and subjected to filtration treatment, the pleat structure will be deformed due to the supply pressure of the liquid to be treated exceeding 0.2 kg/ell, and the filtration performance will also change. Therefore, it is necessary to operate with this level of supply pressure as the upper limit, and therefore, the filtration throughput by a filtration device with an internal volume of 977 cc was 9.51/sin.

That is, it was confirmed that the present invention makes it possible to increase the supply pressure of the liquid to be treated by more than 10 times, and to increase the throughput per unit volume of the filtration equipment by about 10 times. That is, it was confirmed that the method according to the present invention can perform efficient filtration treatment with a compact device, and it was also found that there was almost no change in the filtration results even in continuous filtration treatment over a period of time.

Production Example 2 A stretched porous polytetrafluoroethylene film having a maximum pore diameter of 0.1 μm, a porosity of 70χ, and a film thickness of 60 μm was placed in a housing having the same internal volume of 675 cc as in Production Example 1 above. A piece bent into a pleat shape with a length of 25 mm was set, and the liquid to be treated was filtered through it under the same pressure condition of <1.0 kg/c1a.

As in Production Example 1, a smooth filtration process was achieved, and the throughput was 351/min.

Production Example 3 Same maximum pore diameter as in Production Example 1, 0.2 μm, film thickness 60
A stretched porous polytetrafluoroethylene membrane with a porosity of 76χ in μm was set in a housing with the same internal volume of <675cc, and the liquid to be treated was passed through and filtered under a pressure condition of 1.0 kg/cj.The results are as follows. Since a smooth filtration process was obtained, the pressure conditions for the liquid to be processed were further adjusted to 2.5 k.
g/cd.

In other words, although this pressure was more than 12 times higher than that conventionally used for the same filter medium, it was confirmed that effective and smooth filtration processing could be achieved.

Production Example 4 A stretched porous polytetrafluoroethylene membrane having a maximum pore diameter of 0.3 μm, a film thickness of 60 μm, and a porosity of 75χ was placed in the same housing as in each of the production examples described above, and 1. The liquid to be treated was filtered under a human pressure of 0 kg/cIa.

Filtration throughput is 80 I! /+in, but stable and smooth filtration was achieved as described above.

"Effects of the Invention" According to the present invention as explained above, it is possible to pass the fluid to be treated at a high pressure that exceeds the limitations of conventional filtration equipment of this kind, and therefore, a large amount of filtration processing can be carried out smoothly and in a compact equipment. This invention can be stably implemented and has great industrial effects.

[Brief explanation of the drawing]

The drawings show the technical content of the present invention, and FIG. 1 is a partial sectional view showing one example of the filtration mechanism according to the present invention, and FIG. 2 is a similar version of FIG. 1 showing a modification thereof. Cross section, 3rd
The figure is also a sectional view partially showing a modification thereof. However, in these drawings, 1 is a filter medium, 2 is a housing, 2a is its base, 2b is its cover body, 3 is a treated fluid introduction hole, 4 is a treated fluid outlet hole, and 5 is an auxiliary material. be. Applicant: Japan Gore-Tex Co., Ltd. Inventor: Sadakatsu Hamasaki Agent (patent attorney) Shirakawa 1, Filter medium 2.7, Ujifugu 2a: Uzifugu base 2b: Uziku cup\part 5: Sleeve support material. (

Claims (1)

Claims: (1) A filtration mechanism characterized in that a pleated filter medium is set in a housing under conditions such that deformation and displacement under conditions of flow of a fluid to be treated is suppressed by the housing. (2) The means for suppressing the deformation and displacement of the pleated filter medium in the housing under the flow conditions of the fluid to be treated is fixed to the housing on the peripheral side of the filter medium, and the pleated bent corners are joined to the inner surface of the housing. ,
A filtration mechanism characterized by one or more of mutual interference of folded folds and provision of auxiliary materials such as spacers and nets. (3) Claim characterized in that the peripheral side of the filter medium is sandwiched and tightened between the housing body and the cover body to seal the gap between the housing body and the cover body and fix the filter medium to the housing. The filtration mechanism according to any one of 1 and 2.