JP2766959B2 - Swelling filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to filtration or concentration of suspensions and the like generated when purifying various industrial waste liquids and sewage of water supply and sewerage, or value from various industrial waste liquids. The present invention relates to a filter used for collecting materials and the like.

(Prior Art) Conventionally, as a filter of this type, a cloth filter is mounted on a peripheral surface of a hollow cylindrical body made of a hard synthetic resin having a large number of liquid holes on a peripheral surface thereof through a spacer such as a net. A double-tube structure in which a filtrate collection tube is inserted into the cylinder, a structure in which the filtrate collection tube is removed from the double-tube structure, or a porous hollow cylinder made of a hard material such as ceramic, There are single-tube structures such as those whose porous surface constitutes a filter.In use, these filters are installed in a treatment tank, and the undiluted solution fed to the outer surface of the filter is filtered. The filtrate is taken out through the hollow cylinder and taken out of the tank, and the filter cake deposited on the outer surface of the filter after the required filtration is passed back through the filter from the inside of the filter to the pressurized air sent into the hollow cylinder. Due to A method of peeling from the outer surface of the luter and taking it out of the tank has been performed.

(Problems to be Solved by the Invention) However, in these conventional devices, oxides such as iron ions and manganese ions dissolved in the filtrate at the time of filtration contain a large amount of oxides in the air remaining in the cylindrical body on the inner surface of the filter. Oxygen precipitates due to oxygen, which adheres to the inner surface of the filter, causing clogging, thereby reducing the filtering capacity of the filter, and has the disadvantage of significantly shortening its life.
In addition, in the conventional method that relies only on the backflow of pressurized air in the filter cake peeling, sufficient filter cake peeling cannot be obtained. In many cases, the pressurized air flows out to leave unexfoliated portions, and when the filter is clogged due to the oxidized deposition of the oxide as described above, the blowing of the pressurized air through the filter decreases. As a result, the function of removing the filter cake is reduced, and thus the unfiltered cake is accumulated, which in turn significantly lowers the performance, economy and the like of the filter.

An object of the present invention is to prevent clogging of a filter due to oxidative precipitation of an oxide during filtration and to realize sufficiently reliable separation of filter cake.

(Means for Solving the Problems) As means for solving the above problems, the present invention comprises a tubular or bag-shaped filter, and a filtrate collecting member inserted into the filter and protruding one end out of the filter. The filter is made of a flexible filter sheet, and the filter collecting member is wrapped and flattened by pressure from outside to inside of the filter at the time of filtration. The present invention proposes an expansion / contraction filter, wherein the expansion / contraction filter is deformable so as to expand by a pressure applied to the filter, and the filtrate collection member has a filtrate guide path which is opened in the filter and guides the filtrate in the filter to the outside of the filter. .

In the present invention, the “cylindrical filter” is a filter that maintains a cylindrical shape such as a substantially cylindrical shape, an elliptic cylindrical shape, and a square cylindrical shape in a normal state where pressure is not applied.
It means a filter that keeps a substantially flat bag shape under normal conditions where no pressure is applied.

The "flexible filtration sheet" includes a flexible sheet made of cloth, nonwoven fabric, paper and other various materials and having a filtering ability.

(Operation) In the expansion / contraction filter of the present invention having the above-described configuration,
When the undiluted solution is supplied to the outer surface of the filter by the pressure from the outside to the inside of the filter due to the positive pressure from the outside of the filter or the negative pressure from the inside of the filter, the tubular or bag-shaped filter wraps the filtrate collecting member by the above pressure and becomes flat. Filtration is started in a state where the air shrinks and almost all the air inside the filter is eliminated, so that oxidization and precipitation of iron ions, manganese ions and the like in the filtrate on the inner surface of the filter are sufficiently suppressed. In the removal of the filter cake adhering to the outer surface of the filter, when pressurized air is sent into the filter and pressure is applied from the inside to the outside of the filter, the flat contracted filter rapidly expands and fluctuates. At the same time that the fluctuating impact is applied to the filter cake on the outer surface of the filter, pressurized air flows back from the inside to the outside of the filter, and both functions sufficiently remove the filter cake attached to the filter outer surface from the filter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Example) In FIGS. 1 and 2, short cylindrical caps (2) and (3) are fitted to both ends of an opening of a hose-shaped flexible filtration sheet (1) made of cotton cloth, and both caps ( 2) and (3) are fastened to each other with a band (4) to form a cylindrical filter (5). In such a filter (5), the filtrate collected at both ends is collected. The pipe (6) passes through the center of the cap (2) at one end, and passes vertically to the vicinity of the cap (3) at the other end, and a protrusion (7) of an appropriate length projects from the cap (2) at one end. In this state, the cap (2) is watertightly fixed to the cap (2) by adhesion, welding, or the like. The filtrate collection tube (6) has a plurality of through-holes formed in the periphery of a portion located in the filter (5). The inside of the filter (5) communicates with the inside of the filter (5) through the open end of the projection (7) as a filtrate guide path (9). (10) is a male screw portion provided with the protruding portion (7). A large number of filters having the above-described structure are passed through the projection (7) from below through a partition plate (11) that divides the inside of the processing tank into an upper chamber and a lower chamber. Ten)
The nut (12) is fastened and suspended in the lower chamber. (13) is packing.

In use, the undiluted solution is pumped into the lower chamber, whereby the undiluted solution is supplied to the outer surface of the filter (5) at a positive pressure.
The cylindrical flexible filter sheet (1) shrinks flatly while wrapping the filtrate collecting tube (6) as shown in Fig. 2a while excluding the air inside, and the filtrate collecting tube (1) of the sheet (1) is shrunk. In the portion not in contact with 6), the inner surfaces of the sheets are superposed, and filtration is started in a flat state containing almost no air. The undiluted solution is filtered over the flattened filter sheet (1), the filter cake is captured on the outer surface of the sheet (1), and the filtrate is immediately collected at the filtrate collecting port (8) at the portion surrounding the filtrate collecting pipe (6). )
... through the filtrate guide path (9), and in the superposed portion on the inner surface of the sheet, through the minute gap of the superposed portion, and the filtrate collecting pipe (6)
, And similarly sent from the collecting ports (8)... Into the guide paths (9), respectively, so that the filtrate hardly comes into contact with air at the stage of seeping out to the inner surface of the filter sheet (1), and therefore Iron ions, manganese ions and the like in the filtrate hardly cause oxide precipitates to adhere to the inner surface of the filter sheet (1). The filtrate sent into the collection pipe (6) is sent to the upper chamber through the filtrate guide path (9), where it is taken out of the treatment tank by an appropriate pipe.

In the step of removing the filter residue adhering and depositing on the outer surface of the filter (5) after the required filtration, pressurized air is injected from the projecting portion (7) opening end of the filtrate collecting tube (6) into the collecting tube (6). And the air blown out from the filtrate collecting port (8) and the lower end of the pipe (6) rapidly expands the flat filtration sheet (1) into the cylindrical shape shown in FIG. The filter sheet (1) is blown out from the inside to the outside, and the filter cake on the outer surface of the filter sheet (1) is sufficiently peeled off by the fluctuating impact of the filter sheet during expansion and air blowing.

The filtrate collecting tube (6) in the above example can be replaced with collecting tubes (6a) and (6b) as shown in FIGS. 3 and 4, and the collecting tube (6a) in FIG. On the side surface, there are four filtrate guide paths (9a) consisting of grooves extending over the entire length in the generatrix direction, and the opening of each groove corresponds to the filtrate inlet (8a). The collecting pipe (6b) is provided with a filtrate collecting port (8b) formed of a notch over the entire length in the generatrix direction on the peripheral wall of the hollow pipe, and the inside of the pipe is used as a filtrate guide path (9b). (15a), (1
5b) is a collecting tube (6a), (6b) is a sleeve fitted to the upper end, and the portion of the sleeve is fixed to the cap (2) in FIG. 1 and penetrates into the partition plate (11). Good to do.

5 and 6 show another embodiment in which the peripheral wall of the portion of the filtrate collecting tube (6c) located inside the filter (5c) is provided with two lines in the generatrix direction.
Provide two split grooves (16c) and (16c), and in both split grooves,
The intermediate portion of the rectangular plate-like spacer (17c) made of a corrugated plate is inserted and clamped, and the spacer (17c) and the collecting pipe (6c) are inserted.
Is bound with a string (18c), and the collection tube with spacer (6c)
Is inserted into the cylindrical filter (5c), and the other structure is substantially the same as that shown in FIGS. 1 and 2. The cylindrical filter sheet (1c) supports the spacer (17c) at the time of positive pressure filtration. It easily flattens and intervenes in the polymerized portion on the inner surface of the sheet (1c) to promote the flow of filtrate.

The filter shown in FIGS. 7 and 8 is a bag-shaped filter (5d) obtained by sewing a flexible filter sheet (1d) made of non-woven fabric into a flat bag shape.
And a filtrate collecting tube (6d) is inserted from one end of the bag-shaped filter, and one end of the filter (5d) is fastened to the collecting tube (6d) with a band (4d). The structure is substantially the same as in FIGS. (19d) is a packing receiving flange fixed to the protruding portion (7d) of the collecting pipe (6d). According to this example, the bag-shaped filter (5d) is further flattened as shown by the solid line in FIG. 8a at the time of filtration by the undiluted solution pumping, and as shown by the imaginary line at the time of peeling the filter cake by the pressurized air back-feeding. It expands cylindrically.

Another embodiment of FIG. 9 is a filtrate collection rod (2e) in which a plurality of hollow or solid rods (in this example, two hollow rods and four solid rods) are bound by a string (18e). 6e), a filtrate collecting rod (6) having a spacer (17e) similar to that shown in FIGS.
Using e), the other structure is substantially the same as that shown in FIGS. In this example, the vertical grooves and spaces formed between the adjacent rods are also the filtrate guide paths (9e). A sleeve similar to that shown in FIGS. 3 and 4 may be provided at the upper end of the collecting rod (6e).

Still another embodiment of FIG. 10 uses a spacer (17f) and a filtrate collecting plate (6f) having a filtrate guide path (9f). Is substantially the same as that shown in FIGS.

As shown in FIG. 11, the spacer and filtrate collecting plate (17 g) and the filtrate collecting plate (6
g), in this case a bag filter (5g)
Is sewn (20 g) to each radial tip of the radial spacer / filtrate collecting plate (6 g) so that flattening and expansion are performed at the corners formed by adjacent radial plates.

Also, in each of the above examples, if the filter air cannot be rapidly and sufficiently expanded even if the pressurized air for removing the cake is sent back into the filter through the filtrate collecting member, a dedicated pressurizing method for the filter is used. An air supply pipe may be connected, or the upper end of the filter may be opened to the upper chamber via a partition plate, and a pressurized air supply pipe may be connected to the upper chamber. Twelfth
The figure shows the latter example, in which the cap (2h) is opened to the upper chamber.

(Effect of the Invention) According to the expansion / contraction type filter of the present invention, when the undiluted solution is supplied to the filter by the pressure from the outside to the inside of the filter and the filtration is performed, the filter contracts flatly and removes the air inside. Almost eliminated, thereby suppressing oxidative precipitation of iron ions and manganese ions in the filtrate on the inner surface of the filter, sufficiently preventing clogging of the filter and pressurizing the filter from inside to outside. When removing filter cake by backflow of air, make sure that the filter residue adhering to the outer surface of the filter is sufficiently peeled off due to the fluctuation impact of the filter surface due to the sudden expansion of the flat contracted filter and the backflow of pressurized air. You can do it.

[Brief description of the drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a longitudinal sectional front view of a filter, FIG. 2 is an enlarged sectional view taken along the line II-II of FIG. 1, FIG. Fig. 4, Fig. 4 is an enlarged perspective view of another example of the filtrate collecting tube, partly omitted, Fig. 5 is an enlarged cross-sectional view of another example of the filter, and Fig. 6 is the example of Fig. 5 with spacers. FIG. 7 is a vertical sectional front view of another embodiment of the filter, and FIG. 8 is VIII of FIG.
FIG. 8a is an enlarged cross-sectional view of another embodiment of the filter, and FIG. 10 is an enlarged cross-sectional view of another embodiment of the filter. View, No.
FIG. 11 is an enlarged cross-sectional view of another embodiment of the filter,
FIG. 12 is a longitudinal sectional front view of another embodiment of the filter. 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g ... flexible filtration sheet, 5, 5a, 5b, 5c ... tubular filter, 5d, 5e, 5f,
5g ... bag-shaped filter, 6, 6a, 6b, 6c, 6d ... filtrate collecting tube, 6e ... filtrate collecting rod, 6f, 6g ... filtrate collecting plate, 9,
9a, 9b, 9c, 9d, 9e, 9f, 9g ... Filtrate guide path.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuyuki 5-5-116 Hongo, Bunkyo-ku, Tokyo Organo Co., Ltd. (72) Hiroyuki Hirokawa 5-5-16-1 Hongo, Bunkyo-ku, Tokyo Organo (56) References JP-A-62-125808 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01D 29/00-29/96

Claims (1)

(57) [Claims] 1. A filter comprising: a tubular or bag-shaped filter; and a filtrate collecting member inserted into the filter and having one end protruding outside the filter. The filter collecting member is wrapped and flattened by pressure from outside to inside of the filter, and is deformable so as to expand by pressure from inside to outside of the filter when the filter cake is peeled off. An expansion / contraction filter, wherein the collection member has a filtrate guide path that opens into the filter and guides a filtrate in the filter to the outside of the filter.