JPH08187409A - Filter medium - Google Patents

Abstract

PURPOSE: To remove a cake efficiently from a cylindrical filter cloth in a backward washing and, at the same time, enable the filter cloth to be attached to cylindrical filter frames of various sizes by covering the cylindrical filter frame having perforations with the cylindrical filter cloth in a bellows fashion. CONSTITUTION: A cylindrical filter cloth 13 spreads as a cover on a cylindrical filter frame 12 with plural perforations12A in a bellows fashion according to the length of the filter frame 12. If a cake accumulates on the filter cloth 13 to clog the cloth 13, the filter cloth 13 is washed by removing it from the filter frame 12 or backward washed by injecting under pressure a cleaning water from the outer or the inner side of the filter cloth 13. In both of these cases, the cake sticking to the surface of the filter cloth 13 scales off by stretching/ shrinking and fluctuating the filter cloth 13 applied as a cover to the filter frame 12 in bellows fashion. In aaddition, the cake is removed from the filter cloth 13 by the pressure of the cleaning water. Consequently, the cake accumulating on the filter cloth 13 is easily removed, and filter media of various sizes with the same filtration area are obtained by properly selecting the sizes of the filter frame 12.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a filter material.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIG. 8, there is provided a filter medium (1) in which a perforated filter frame (2) is covered with a filter cloth (3). In order to carry out filtration with the filter material (1), the liquid to be treated is introduced into the filter frame (2) from the liquid to be treated introduction path (4) connected to one end of the filter frame (2), The treatment liquid is filtered by the filter cloth (3) through the hole (2A) of the filter frame (2). In the filtration step, the solid content (cake) contained in the liquid to be treated is accumulated inside the filter cloth (3), and the filtrate is discharged outside the filter cloth (3). Filter cloth (3)
If the cake is clogged with cake, the washing water is pressed in from the outside of the filter cloth (3) in the reverse of the filtration process,
A backwashing step of removing the cake accumulated inside (3) by the pressure of the washing water is performed.

[0003]

However, the above-mentioned conventional filter material has a problem that it is difficult to remove cake efficiently from the filter cloth by the backwashing step.

[0004]

As a means for solving the above-mentioned conventional problems, the present invention is a bellows having a cylindrical filter cloth (13) in a cylindrical hole (12A) and a clear filter frame (12). Shaped filter
(11) is provided.

[0005]

In the present invention, the filter cloth (13) can be expanded and contracted according to the size of the filter frame (12) to provide the filter media (11) of various sizes without changing the filtration area. In the filter material (11) of the present invention, the liquid to be treated is press-fitted into the filter frame (12) from one end of the filter frame (12), and the filter cloth is passed through the holes (12A) of the filter frame (12). The liquid to be treated is filtered by (13), or the liquid to be treated is pressed from the outside of the filter cloth (13) and filtered. In the former case, the cake is accumulated inside the filter cloth (13), the filtrate is discharged outside the filter cloth (13), in the latter case, the cake is accumulated outside the filter cloth (13) and the filtrate is filtered. It flows from the inside of the cloth (13) into the inside of the filter frame (12) through the hole (12A). When cakes are accumulated on the filter cloth (13) and become clogged, the filter cloth (13) is removed from the filter frame (12) and washed, or the outside or inside of the filter cloth (13) is washed. Backwash by pressing in the washing water. In any case, the filter cloth (13) adhered to the filter frame (12) in a bellows shape expands and contracts, whereby the cake adhering to the surface of the filter cloth (13) is peeled off, and further washed. It is removed from the filter cloth (13) by the pressure of water.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. The filter material (11) shown in the figure is a cylindrical filter frame (1) having a plurality of holes (12A).
2) and a cylindrical filter cloth (13) coated on the filter frame (12), and the filter cloth (13) is formed into a bellows shape according to the length of the filter frame (12). ing. Therefore, the filter frame (12) is the filter cloth (13).
Although it is set to be shorter than the maximum length of the filter, it can be attached to filter frames (12) of various sizes by expanding and contracting one size of filter cloth (13). Both ends of the filter cloth (13) are removably attached to the filter frame (12) by fixing rings (14), and a tight plug (15) is fitted to one end of the filter frame (12). A stopper (1) with an opening (17) at the end
6) is fitted.

The filter medium (11) is used for purification of water in the lake (10) as shown in FIG. 2, for example. In this case, the filter material (11) is thrown into the lake (10), and the floating plate (19) with the pump (18) installed is floated on the water W of the lake (10). A water injection hose (20) is connected to the opening (17) of the pump (18) from the outlet side of the pump (18), while a water suction hose (21) is connected to the inlet side of the pump (18). A net basket (23) containing a cloth bag (22) filled with a coagulant such as aluminum sulfate is attached to the tip of the water absorption hose (21).

In the above structure, when the pump (18) is operated, the water in the lake (10) is sucked from the water absorption hose (21) through the net (23), and at this time, the coarse net in the water is caused by the net (23). Solids are blocked and small solids such as green algae A floating in water are sucked into the water absorption hose (21) together with water. The water W
Is mixed with the coagulant that is eluted from the cloth bag (22) in the net basket (23) and is sucked into the water absorption hose (21), and the small solid content of the water W starts to coagulate. The water W is press-fitted into the filter medium (11) by the pump (18) through the water press-fitting hose (20), and is discharged from the hole (12A) of the filter frame (12) to the outside of the filter frame (12). Filter cloth
Aggregates and the like of green alga A are filtered by (13), and the filtrate is discharged to the outside of the filter cloth (13) and returned into the water W of the lake (10).

If a cake such as an agglomerate of green alga A accumulates inside the filter cloth (13) and becomes significantly clogged, the pump (18)
Stop the water injection and stop the water injection hose (20)
Remove from (11) and remove the filter material (11) from the lake (10). As shown in FIG. 3, the cake C adheres to the inside of the filter cloth (13). Therefore, when pressure water is sprayed onto the filter medium (11) from the outside, the filter cloth (13) is removed as shown in FIG. It is pressed by water pressure from the outside to expand and contract, at which time the cake C is peeled off from the inner surface of the filter cloth (13), and the cake C clogged in the filter cloth (13) is also removed by water pressure. In this way filter cloth (13)
The cake C removed from the filter is discharged as drain from the end of the filter frame (12) to the outside. Filter cloth (1
In addition to removing the cake from 3), the filter cloth (13) may be removed from the filter frame (12) and washed. Also at this time, the cake C is easily peeled off from the filter cloth (13) due to the expansion and contraction of the filter cloth (13).

The filter material (11) of this embodiment may be set in the filter tube (24) as shown in FIG. In this case, a valve (26) is attached to the filtration cylinder (24) and a liquid inlet (25) to be treated in which the pump (27) is interposed is connected, and the opening (17) of the filtering material (11) is further connected. A filtrate discharge passage (28) having a valve (29) is connected to the drain pipe, and a drain discharge port (30) provided with a valve (31) is connected to the bottom of the filtration cylinder (24). In this case, the pump (27) is operated so that the liquid to be treated containing the solid content is injected into the liquid to be treated (25).
From the filter medium (12) is pressed into the filter cylinder (24), the liquid to be treated is filtered by the filter cloth (13) of the filter material (11), and the filtrate is discharged from the filter frame (12) of the filter material (11). Discharge to road (28). And FIG.
Cake C accumulates on the outside of the filter cloth (13) as shown in FIG. If the filter cloth (13) becomes clogged, stop pressing the liquid to be treated,
The filtrate or the washing liquid is press-fitted into the filter medium (11) from the filtrate discharge passage (28). As shown in FIG. 7, the filter cloth (13) expands and contracts due to the liquid pressure of the filtrate or washing liquid, and the cake C is the filter cloth (13).
When the filter cloth (13)
Cake C clogged in 3) is also removed by the liquid pressure. After backwashing the filter cloth (13) in this way, the valve (31)
Open to drain the drain from the drain outlet (30).

Although the liquid to be treated is passed from the outside to the inside of the filter medium (11) in the above-mentioned use example, the liquid to be treated is discharged through the filtrate discharge passageway (28).
Alternatively, the liquid to be treated may be pressed into the filter material (11) from the inside to the outside. In this case, of course, backwashing is performed from the outside to the inside, but the liquid to be treated is further filled in the filter medium (11), the valve (29) is opened, and the liquid to be treated is discharged into the filtrate discharge path (2).
When the pressure inside the filter medium (11) is reduced by discharging it to (8), the cleaning liquid is forcibly sucked from the outside of the filter cloth (13),
The cleaning effect of the filter cloth (13) is remarkably improved.

[0012]

Therefore, according to the present invention, the cake accumulated on the filter cloth of the filter medium can be easily removed, and by properly selecting the filter frame size, the filter area can be the same and various sizes of filter medium can be obtained. .

[Brief description of drawings]

 1 to 7 show an embodiment of the present invention.

FIG. 1 is a sectional view

[Figure 2] Illustration used to purify water in lakes and marshes

FIG. 3 is a state diagram of a filter cloth on which cake is accumulated.

FIG. 4 is a state diagram of the filter cloth with the cake peeled off.

FIG. 5 is an explanatory diagram in which a filter medium is set in a filter cylinder.

FIG. 6 is a state diagram of a filter cloth on which cake has accumulated.

FIG. 7: State diagram of filter cloth with cake peeled off

FIG. 8 is a sectional view of a conventional example.

[Explanation of symbols]

 11 Filter material 12 Filter frame 12A hole 13 Filter cloth

Claims (1)

[Claims] 1. A filter material comprising a cylindrical perforated filter frame covered with a cylindrical filter cloth in a bellows shape.