JPH02115009A - Disc filter - Google Patents

Abstract

PURPOSE:To reduce liquid retaining areas of a disc filter by providing a retainer for holding filter material with a hub, blades and a ring, the surface of the blade being set at right angles to the disc surface, one end thereof along the outer periphery of the hub and the other end thereof along the inner periphery of the ring. CONSTITUTION:The liquid to be filtered is directed toward the inside of a disc filter provided with filter material 5 on both sides thereof and carried out through an opening 6 of a central hub 1 thereof. A retainer for holding the filter material 5 consists of a hub 1, blades 2 and a ring 3. The blades 2 are arranged with the surface thereof set at right angles to the disc surface, one end thereof along the outer periphery of the hub 1 and the outer end thereof along the inner periphery of the ring 3. The blade 2 is curved at right angles to the disc surface and a space between each adjacent blade is nearly equalized regardless of the distance from the center of the disc filter, resulting in a reduction in the liquid retaining areas and pressure loss.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a filter for removing foreign matter from a fluid. In particular, the present invention relates to the improvement of a disk filter that can have a large filtration area and is used as a highly accurate filter for removing highly viscous fluids such as molten polymers and minute foreign matter.

(Prior art) Conventionally, disk filter retainers have sufficient strength to withstand high differential pressures and allow fluid to easily pass through, but the structure and manufacture of these retainers has been difficult, and the flow resistance in the retainer has been greatly improved. Figure 3 shows what has been conventionally used.

Both sides of thick gold 1218 are sandwiched between punching metals 7 and the filter medium 5 is covered from above.The thick wire mesh 8 is strong against compression and has sufficient strength, but it is complicated as a flow path.
Pressure loss is large.

Further, since the mesh is coarse, it is not possible to directly support the filter medium 5, and punching metal 7 is required as a reinforcing material.

Naturally, in the punched metal 7, filtrate cannot flow anywhere other than the openings, and filtrate tends to stagnate.

In the case of a filtrate that is denatured, such as a molten polymer, there are drawbacks such as denaturation of the retention area.

In addition, the thick wire mesh 8 has a constant thickness, and in the case of a disc filter where the flow rate of filtrate gathers and becomes larger at the center, the thickness is set at the center compared to the outer periphery in order to enlarge the flow path at the center. It is also impossible to increase the height of the retainer.

(Problems to be Solved by the Invention) An object of the present invention is to provide a disk filter having a retainer structure with few retention parts and low pressure loss.

[Means to solve the problem]

The disc filter of the present invention is a disc filter in which filter media are provided on both sides of the disc, and the filtrate flows from the outside to the inside and is taken out from a hole in a hub provided in the center. The blades are characterized in that the blade surfaces are arranged at right angles to the disk surface, and one end is arranged along the outer periphery of the hub and the other end is arranged along the inner periphery of the ring.

(Function) In the disk filter configured as described above, the fluid to be passed through the line passes through the filter medium provided on the outer surface of the disk filter and flows into the inside of the disk filter. On this occasion,
Foreign matter that cannot pass through the filter medium is removed. The fluid that has flowed into the disk filter moves through the space between the blades and the adjacent blades toward the holes provided in the hub. Since this space is not occupied by a thick wire mesh as in conventional disc filters, the pressure loss as a flow path is small and there are few fluid retention areas.

〔Example〕

The structure of the present invention will be explained along with examples.

FIG. 1 is a plan view showing one embodiment of the disc filter of the present invention, and for easy understanding, the filter medium 5, wire mesh 4
The figure is shown with a part removed.

In the figure, 1 is a hub, which has a hole 6 as a fluid passage. Blades 2 are arranged at right angles to the flat surface of the wire mesh 4 and the filter medium 5, and the height of the blades is visible in FIG.

As shown in FIG. 2, which is a cross-section of FIG. It is gradually decreasing.

In addition, the blades 2 are curved to compensate for the fact that if they were simply arranged radially, the gap between the blades and the adjacent blades would become wider toward the outer periphery, which would be disadvantageous in terms of pressure resistance design.

The above curving method can be achieved by following the following formula. That is, the diameter passing through the center O of the disk filter is the blade 2.
Let X be any point that intersects with When the length of the radius of the outer periphery is determined as R8, it is curved so as to form a curve determined by cosα=Ro/Rx.

If the above curve is used, the gaps between adjacent blades will be exactly equal over the entire surface of the disk filter, and the strength of the wire mesh 4 provided between the blades and the filter medium will be easily designed.

Due to the above curvature, the length of the flow path along the blade from the outer periphery toward the center is naturally longer than that in the case of a simple radial arrangement, resulting in an increase in pressure loss. The advantage of being almost equal is greater, and the pressure loss can be significantly reduced compared to the conventional type in which the thick wire mesh 8 is used as a retainer.

The ring 3 fixes and strengthens the arrayed blade group, and is effective in precision casting such as lost wax, where the blades 2, ring 3, and hub 1 are integrally molded at the same time. It is also possible to press the blade 2 and ring 3 and weld them to the hub 1 later.

It goes without saying that by sintering the wire mesh 4 to the hub 1, blade 2, and ring 3 by heat compression, a disk filter with high strength and good pressure resistance can be constructed as a retainer for supporting the filter medium 5.

The disc filter of the present invention particularly requires pressure resistance,
If used for filtration of molten polymer, where pressure loss in flow paths other than the filter media portion is to be avoided, and the presence of fluid retention portions is to be avoided, the effects will be significant.

That is, by reducing the pressure loss in parts other than the filter medium, the equipment can be strengthened accordingly.

Alternatively, with respect to the increase in the pressure applied to the disk filter due to the removal of foreign matter, the pressure loss of the entire disk filter is reduced, which is advantageous, and the life of the disk filter can be extended.

Furthermore, since the retention area where the polymer is difficult to flow is reduced, deterioration of the polymer can be suppressed and quality can be improved.

〔Effect of the invention〕

The disc filter of the present invention has few retention areas and low pressure loss.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of the present invention, with a part removed for ease of understanding, Fig. 2 is a sectional view of Fig. 1, and Fig. 3 is a conventional disc filter. This is a cross-sectional view. 1...Hub, 2...Blade, 3...Ring, 4
...Wire mesh, 5...Filtering medium, 6...Hole, 7...Punching metal, 8...Thick wire mesh

Claims (5)

[Claims] (1) In a disc filter in which filter media are provided on both sides of the disc, and the filtrate flows from the outside to the inside and is taken out from the hole in the hub provided in the center, the retainer that supports the filter media is attached to the hub,
A disk filter comprising a blade and a ring, the blades being arranged with the blade surface perpendicular to the disk surface, one end along the outer periphery of the hub, and the other end along the inner periphery of the ring. . (2) Curve the blade in a direction perpendicular to the blade surface,
2. The disk filter according to claim 1, wherein the gaps between the blades are substantially equal regardless of the distance from the center of the disk filter. (3) The disk filter according to claim 1, wherein the height of the blade gradually decreases from the end circumscribing the blade to the other end inscribing the ring. (4) The disc filter according to claim 1, characterized in that a wire mesh having a higher pressure resistance than the filter medium is inserted between the retainer and the filter medium. (5) The disk filter according to claim 4, wherein the filter medium is covered after the wire mesh and the retainer are sintered in advance.