JPS6090017A - Filter apparatus - Google Patents

Abstract

PURPOSE:To prolong the filtering life of the entire filter apparatus and to reduce pressure loss, by preventing generation of a part, where the stay time of a fluid becomes long in the filter apparatus, and uniformizing the flow amount load of each disc shaped filter. CONSTITUTION:Because the inside measure cross-sectional area of a casing is contracted in a flow direction by a taper surface 35 and the cross-sectional area of a flowline 34 is gradually contracted, the divided flow speed thereof is suppressed. In addition, in the flow direction, the cross-sectional area of the flowline 34, that is, the capacity thereof is set only in a throttled direction and, therefore, the lowering in a flow speed is suppressed without promoting the lowering in the flow speed by the enlargement of the cross-sectional area and the stay time of the fluid in the flowline 34 is shortened. Further, because flow speed distribution can be received within a definite range by suppressing the lowering in the flow speed, the flow state to each disc shaped filter is uniformized to make it possible to uniformize flow amount load and the filtering life as the whole of the filter apparatus can be prolonged by uniformizing flow amount load.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a filtration device for separating and filtering solid particles or gel-like substances mixed in a fluid, and in particular, the present invention relates to a filtration device that separates and filters solid particles or gel-like substances mixed in a fluid. Regarding the structure of the filter device.

Prior Art Conventionally, it has been known that the fluid is a high viscosity substance such as a molten polymer substance, the size of solid particles or gel-like substances to be separated is several tens of microns to several tens of microns, and the amount of fluid to be processed is As shown in Fig. 1, in a filtration device with a large amount of volume, so-called high capacity and large capacity, a filtration device is generally used in which disc-shaped filters 1 are stacked and housed in a casing 2 in multiple stages to provide a large filtration area. It is used. The fluid flowing in from the inlet 3 flows down a flow path 4 between the inner surface of the casing 2 and the laminated disk-type filters 1, and is filtered by passing through the disk-type filters 1 in order from the flow path 4. , the filtered fluid is collected within the strut 5 and exits through the outlet 6.

However, in such a filtration device, a part of the fluid flowing through the flow path 4 sequentially flows toward the disc-type filter 1 side, so the flow rate in the flow path 4 decreases accordingly, and the cross-sectional area of the flow path 4 becomes smaller in the flow direction. Since the flow rate is constant, the flow velocity decreases toward the downstream side. Therefore, the flow velocity is the slowest at the bottom of the flow path 4 (and the residence time becomes long).If the residence time is too long, gelation will progress in high-temperature, high-viscosity fluids, causing quality deterioration. be.

In order to prevent this, if the cross-sectional area of the flow path 4 is made small,
The overall pressure loss increases, which is disadvantageous for the equipment, and the shearing rate increases, which may cause quality deterioration due to shearing.

Furthermore, the flow m passing through each disc-shaped filter 1 is determined by the balance between the pressure distribution in the flow direction in the flow path 4 and the pressure distribution in the flow direction in the struts 5, but compared to the conventional device in which the cross-sectional area of the flow path 4 is constant. In this case, it was difficult to make the flow load of each disc-type filter 1 uniform. If the flow rate load is uneven, some disk-type filters 1 that clog quickly and others that clog slowly will coexist, making it impossible to effectively utilize the entire disk-type filter, and reducing the filtration life of the filtration device as a whole, i.e. A problem has arisen in that the life cycle is shortened and the number of filter replacements increases, resulting in a corresponding decrease in productivity.

Furthermore, if the flow rate load on each disc filter 1 is uneven, the pressure loss in each disc filter 1 will vary widely, creating a flow section with a large pressure loss, resulting in a large pressure loss in the filtration device as a whole. Therefore, there is a problem in that the load on the equipment located upstream of the filtration equipment increases accordingly, resulting in a disadvantageous situation for the equipment.

Purpose of the Invention The present invention, in order to solve the above problems, prevents the formation of a portion where the fluid residence time is long in the filtration device, and
Another object of the present invention is to equalize the flow rate load of each disc type filter, thereby extending the filtration life of the entire filtration device and reducing pressure loss.

Structure and operation of the invention The filtration device of the present invention that meets this objective stores disc-shaped filters stacked in multiple stages within a casing, and the flow path between the inner surface of the casing and the stacked disc-shaped filters is aligned in the stacking direction of the disc-shaped filters. In the filtration device, the inner cross-sectional area of the casing gradually decreases at least partially along the flow direction of the fluid in the flow path, and The inner cross-sectional area of the casing on the downstream side of the passage is not larger than the inner cross-sectional area on the upstream side.

In such a filtration device, the cross-sectional area of the flow path between the casing and the laminated disc filters is gradually reduced over the entire length or in parts, as viewed in the flow direction, and after being reduced. is not enlarged again, this prevents a significant drop in the flow rate of the fluid whose flow rate decreases downstream, and the residence time of the fluid in the flow path is suppressed to below a certain value, improving the quality of the fluid due to residence. Deterioration is prevented.

In addition, by suppressing the decrease in flow velocity and keeping the flow velocity within a certain range, the flow condition to each disc type filter is equalized, and the flow load is equalized, which reduces the lifespan of each disc type filter and reduces pressure loss. is equalized. When lifespans are equalized, each disc type filter reaches its lifespan at approximately the same time, resulting in a longer filtration life for the entire filtration device.When pressure loss is equalized, fluid flows through which path within the filtration device. However, the pressure loss is kept within a certain range, and the pressure loss of the filtration device as a whole is minimized, thereby achieving the intended purpose.

EXAMPLES Below, preferred examples of the filtration apparatus of the present invention will be described with reference to the drawings.

FIG. 2 shows a filtration device according to an embodiment of the present invention, and in the figure, 11 is a cylindrical container-shaped casing. The casing 11 includes a cylindrical body tube 12, an upper cover 14 provided at the upper part of the body tube 12 and having a fluid inlet 13, and a lower cover 16 provided at the lower part of the body tube 12 and having a fluid outlet 15. Ru.

Inside the casing 11 is a disc-shaped filter 1.
7 are stored stacked in multiple stages. The disk-shaped filter 17 is assembled on the support 18 by being stacked in multiple stages, and is fastened and fixed between the bottom plate 19 of the support 18 and a presser plate 20 attached to the top of the support 18. The disk type filter 17 includes, for example, FIGS. 3 and 4.
As shown in the figure, it is composed of a filter medium 21, a reinforcing wire mesh 22 provided inside the filter medium 21 to support the filter medium 21, and an annular hub 24 provided on the inner peripheral side of the filter medium 21 and having holes 23 for fluid passage. As shown in FIG.
．． 27, and a ring 28 is interposed between each filter, and a hole 29 for fluid passage is provided on the outer peripheral surface of the ring 28.
A filter medium 25, a type that filters through the hole 30 of the hub 27, etc. are used.

The inside of the strut 18 is formed with a fluid passage 31, and the fluid that has passed through the disc-shaped filter 17 enters the space 32 between the strut 18 and the inner peripheral surface of the disc-shaped filter 17, and the strut 1.
8 is led to the outlet 15 through a hole 33 and a passage 31.

A fluid flow path 34 having an annular cross section is formed between the inner surface of the casing 11 and the stacked disk-shaped filters 17. In this embodiment, the fluid flowing in through the inlet 13 flows through the flow path 34 from above to below as indicated by the arrow. The inner surface of the casing 11 is formed such that its inner cross-sectional area gradually decreases, at least partially, along the fluid flow direction from above to below. In this embodiment, the inner diameter Do of the casing 11 is
It is set to be gradually reduced to Dl from the middle of the flow path 34 to the lower end, and the inner surface in this period is formed into a tapered surface 35 with a linear cross section.

This tapered surface 35 may be curved as necessary. Further, as shown in FIG. 6, the tapered surface 35 may be provided further down the flow path 34, or as shown in FIG. 7, it may be provided only in the middle of the flow path 34. Furthermore, as shown in FIG. 8, a tapered surface 35 may be formed over the entire length of the flow path 34. Where the tapered surface 35 is provided and the shape of the tapered surface 35, that is, the dimensional ratios of D1/Do and L1/lo in FIG. It is determined by the diameter of the column, the pressure loss of the fluid in the strut 18 and other parts, etc.

In addition to being provided with the above-mentioned tapered surface 35, the inner surface of the casing 11 is shaped in accordance with the following conditions. That is, the inner cross-sectional area on the downstream side of the flow path 34 is set not to be larger than the inner cross-sectional area on the upstream side. Therefore, the inner diameter of the casing 11 on the downstream side is equal to the inner diameter on the upstream side, or is reduced by the tapered surface 35, or is reduced by the tapered surface 35 and then equal to the inner diameter on the upstream side, or even gradually. is either reduced to or set to .

In the embodiments shown in FIGS. 2 and 6, the tapered surface 3
5, the inner cross-sectional area is not reduced and reaches the lower end of the flow path 34, and in the embodiment shown in FIG. In the embodiment shown in FIG. 8, the inner cross-sectional area is not reduced over the entire length until reaching the lower end.

The operation of the filtration device configured as described above will be described below.

First, regarding the fluid flow path, the casing 1
The fluid flowing in from the inlet 13 of the casing 11 spreads in the radial direction at the upper part of the casing 11 and flows into the flow path 34.
As the water flows down, a part of it passes through the disk filter 1.
It flows in 7 directions. fj! The fluid that has flowed toward the imprinted disk-type filter 17 is filtered by passing through the filter medium portion of each disk-type filter 17, passes through the space 32 and the hole 33, and is collected in the passage 31 in the strut 18, and then exits to the outlet. It is leaked from 15.

Of this fluid flow, in the flow in the flow path 34, the fluid flows in the direction of the disc-shaped filter 17, so the flow rate decreases and the flow velocity tends to decrease, but the inner cross-sectional area of the casing 11 Since the cross-sectional area of the flow path 34 is gradually reduced in the flow direction, a decrease in the flow velocity is suppressed. Moreover, in the flow direction, the cross-sectional area of the flow path 34, that is, the capacity of the flow path 34, is set only in the direction of constriction, so that the decrease in flow speed is suppressed without being promoted by increasing the cross-sectional area. The residence time of the fluid within the flow path 34 is reduced.

The residence time is determined by the setting of the tapered surface 35, and is kept below a certain value depending on conditions such as fluid temperature and flow rate, thereby preventing quality deterioration due to residence.

In addition, by suppressing the decrease in flow velocity and keeping the flow velocity distribution within a certain range in the flow direction, that is, in the stacking direction of the disc-shaped filters 17, each disc-shaped filter 17
The state of the flow to each disk type filter 1 is equalized, and
7 is made uniform. Each disc type filter 1
7 is equalized, the time-varying state of clogging of each disk filter 17 is equalized.
Uniform filtration life. Therefore, each disk type filter 17 reaches the end of its life at approximately the same time, and all the disk type filters 17 are effectively used until the end of their life.

Therefore, the filtration device as a whole does not reach the end of its lifespan while any one of the disk-shaped filters 17 still has a margin in terms of lifespan, and the filtration life of the filtration device as a whole is maximized.

Furthermore, when the flow rate load of each disc filter 17 is equalized, the pressure loss is also equalized, so no matter which path the fluid flows through in the device, the pressure loss is kept within a certain range and the pressure loss is reduced. The peak value is suppressed, and as a result, the pressure loss throughout the filtration device is minimized. In addition, in the disc type filter 17, the filtration accuracy tends to decrease as the pressure difference before and after the filter medium becomes larger. Since the filtration accuracy is suppressed to a low level without causing any damage, the filtration accuracy is maintained at the maximum performance determined by the grade of the disc filter 17.

As described in detail, the following various effects can be obtained by using the m-passing device of the present invention.

First, the cross-sectional area of the flow path between the casing and the laminated disc-shaped filters is narrowed in the flow direction, and is also prevented from expanding even after narrowing, thereby suppressing a drop in flow velocity on the downstream side of the fluid. It is possible to prevent the residence time of the fluid from increasing and to prevent the quality of the fluid from deteriorating due to the residence.

In addition, by suppressing the flow velocity drop, the flow velocity distribution can be kept within a certain range, so the flow condition to each disc type filter can be made uniform and the flow rate load can be made uniform. can extend the filtration life.

Furthermore, by equalizing the flow rate load of each disc type filter, the pressure loss of each disc type filter can be made uniform at a low level, and the pressure loss of the filtration device as a whole can be minimized. Another advantage is that advantageous equipment design conditions of low pressure can be obtained for the equipment.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional filtration device, FIG. 2 is a rough sectional view of a filtration device according to an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view of a disk-type filter in the device of FIG. Fig. 4 is a partially sectional plan view of the device shown in Fig. 3; Fig. 5 is a vertical sectional view of another disk-type filter; and Fig. 6 is a partial sectional view showing the inner surface shape of a casing according to another embodiment. FIG. 7 is a partial cross-sectional view showing the inner surface shape of a casing according to yet another embodiment, and FIG. 8 is a partial cross-sectional view showing the inner surface shape of the casing according to still another embodiment. 11... Casing 13... Inlet 15... Outlet 17... Disk filter 18... Support column 21.25...・Filter medium 34...Flow path 35...Tapered surface D+, Do...Inner diameter of casing Fig. 1 S Fig. 2 Fig. 4 Fig. 5 Fig. 2 Day 8 figure

Claims (1)

[Claims] (1) Disk-type filters are stacked in multiple stages and housed in a casing, and the fluid flowing through the flow path between the inner surface of the casing and the stacked disk-type filters in the stacking direction of the disk-type filters passes through the disk-type filters in order. In the filtration device, the inner cross-sectional area of the casing is gradually reduced at least partially along the flow direction of the fluid in the flow path, and the inner cross-sectional area of the casing on the downstream side of the flow path is reduced. , a filtration device characterized in that the inner cross-sectional area on the upstream side is not larger than the inner cross-sectional area.