JPS632092Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a laminated liquid precision filter, and provides a filter in which air pockets do not occur on the surface of the filter medium and impede filtration performance.

A conventional example is a laminated liquid precision filter 1 shown in FIG.
A large number of support plates 3 extending radially around a central shaft 2 having a diameter of 15 mm and a closed lower end are fixed at regular intervals, and each of the upper and lower surfaces 3'a and 3a of the support plates 3 has a mesh structure. A filter medium 4 made of a porous thin film material (for example, tetrafluoroethylene) is adhered to the support plate 3 in a liquid-tight manner to cover the network structure, and the network structure and the hollow part 2a of the central shaft are separated. They are communicated through a passage 3b in the support plate 3. The filter element 5 as described above has an inlet hole 6 for the liquid to be filtered.
a, The support plate is housed in a housing 6 having an outlet hole 6b and an air vent hole 6c located above the housing 6 in use, with the lower surface 3a facing downward, and the open end of the central shaft 2 communicates with the outlet hole 6b. It is fixed in a liquid-tight manner. In FIG. 1, 7 is an air vent plug. Thus, the inside of the housing 6 is divided by the filter element 5 into an inlet hole 6a side, that is, a dusty side, and an outlet hole 6b side, that is, a clean side.

Note that the central axis 2 of the filter element 5
Usually, as shown in FIG. 2, the boss 2' is formed by connecting and fixing the upper and lower end surfaces of a boss 2' which is provided protruding from the center of the support plate 3 and has a hollow hole 2'a.

When the liquid to be filtered is fed into the laminated liquid precision filter 1 as described above through the inlet hole 6a, it is filtered by the filter medium 4 of the filter element 5 and passes through the outlet hole 6b.
However, the air that was stagnated in the housing and the air bubbles mixed in the liquid are unable to pass through the fine pores of the wet filter medium due to the surface tension of the liquid, and the support It stops on the surface of the filter medium 4 attached to the lower surface 3a of the plate 3, becomes an air pocket, and gradually grows. Therefore, the contact between the liquid and the surface of the filter medium is cut off, and the effective filtration area gradually decreases, lowering the filtration capacity. Furthermore, the elasticity of this air reservoir causes unstable pulsations in the pressure of the delivered filtrate. The formation of air pockets and the occurrence of pulsations described above are particularly noticeable in precision filters, as the material is a thin film with no rigidity and is a porous film with a finer pore diameter than other materials, and is an important problem. It becomes a point.

On the other hand, conventional so-called leaf-shaped filters are made by forming and laminating materials into plate shapes with conical inclinations, and are disclosed in Utility Model Publication No. 46-30849 or Japanese Patent Publication No. 42-11873. . Each of these is a plate-shaped material, and to support this material, a support body having a plurality of radial support arms with thicker bases near the center is used. Not only is such a roughly arranged radial support arm inappropriate for supporting a non-rigid membrane to withstand hydraulic pressure, but it is also difficult to use a shape like this support to impart an inclination to the material. In this case, the support becomes thicker as the base of the support arm becomes thicker, and the number of stacked supports that can be accommodated in a housing of the same capacity decreases, resulting in a problem that the excess area in design is reduced.

This idea was developed to solve the above-mentioned problems by making the upper and lower surfaces of the support plate having a network structure into almost parallel conical surfaces, and making it possible to form a thin film without increasing the thickness of the center of the support. The material is sloped to prevent air pockets from forming.

To explain with an example, in FIG.
The laminated liquid precision filter 10 of this invention is the first
A filter element 15 is housed and fixed in a housing 6 similar to the conventional one shown in the figure.
The filter element 15 has a plurality of supporting plates 13 fixed at regular intervals around a central shaft 12 having a hollow portion 12a and a closed lower end and extending in the radial direction. 13a has a mesh structure, and a fine porous tetrafluoroethylene thin film material 4 is adhered to the support plate in a liquid-tight manner so as to cover the mesh structure. The lower surface 13a of the support plate 13 is sloped upward so as to be located upwardly as it moves away from the central axis 12 in the radial direction, forming a gentle conical surface, and the upper surface 13'a
It also forms a conical surface almost parallel to this. The housing 6 is provided with an inlet hole for the stock solution at the lower part, an outlet hole for the liquid at the upper part, and an air vent hole provided with an air vent plug 7, similar to that shown in FIG. is screwed onto.

In the laminated liquid precision filter 10 of this invention having the above-described structure, when the liquid to be filtered is fed, the air in the housing 6 first passes through the support plate 13.
The liquid does not accumulate on the lower surface 13a of the housing 6, but moves upward along the slope of the lower surface 13a and accumulates on the upper part of the housing 6. Furthermore, when the air bubbles mixed in the liquid reach the surface of the filter medium on the lower surface 13a of the support plate, they cannot pass through the filter medium 4 and are blocked, but they float along the slope provided on the lower surface 13a of the support plate and rise to the surface of the housing 6. Collects at the top. Thus, by opening the air vent plug 7 as appropriate, the housing can be removed without tilting.

The laminated liquid precision filter of this invention does not generate air pockets on the surface of the filter medium as described above, and therefore can prevent a reduction in the filtration area and unstable pulsation of the delivered filtrate due to air pockets. Furthermore, the designed filtration area that can be accommodated in the same container as the conventional one is not reduced.

[Brief explanation of the drawing]

Figure 1 shows a conventional laminated liquid precision filter;
The figure shows a portion of a filter element, and FIG. 3 is a sectional view showing an embodiment of this invention. 2, 12... Central shaft, 3, 13... Support plate, 3
a, 13a... Lower surface of support plate, 4... Material, 6...
Housing, 7...Air vent plug.

Claims (1)

[Scope of utility model registration request] A plurality of supporting plates are fixed at intervals around a hollow central shaft with one end closed, each having a mesh structure, the upper and lower surfaces of which are substantially parallel conical surfaces, and which extend in the radial direction. A porous thin film material is attached to the upper and lower surfaces, and the inner side of the material is communicated with the hollow part of the central shaft through the internal passage of the support body to form a filter element, and the filter element is connected to the liquid inlet hole,
A laminated liquid precision filter, which is housed in a housing having an outlet hole and an air vent hole located at the upper part, with the conical surface of the support plate facing upward toward the periphery, and the hollow part is communicated with the outlet hole. .