JPH06254316A - Filter device - Google Patents

Abstract

PURPOSE:To filter water or low viscosity liquid by using a flocculation separation bed where a filter bag by an onefold filter net of synthetic resin such as tetrafluoroethylene resin is included and a filter where plural filter nets different in mesh connected to the bed are arranged in order of mesh size from below. CONSTITUTION:A flocculation separation bed 1 is constituted by using a onefold filter net by highly nonadhesive synthetic resin such as either one or a combination of PKF (tetrafluoroethylene resin), PFA (tetrafluoroethylene-fluorinated fluoroalkyl vinyl ether copolymer resin) and FBE (tetrafluoroethylene- hexafluoropropylene copolymer resin). When fine suspended solid particles and colloid particles of <=5mu particle diameter and further sludge in a dissolved state are previously flocculated and precipitated by the flocculation separation bed 1, since the filter net is highly nonadhesive, the precipitate is not stuck to the side wall and bottom part inside a storage chamber and is filtered. Then, solid particles other than those are filtered by a filter 2 where plural filter nets are arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtering device used for filtering water or low viscosity fluid.

[0002]

2. Description of the Related Art Usually, a sand filtration method is used for filtering water and the like.

In the sand filtration method, fine solid particles smaller than the space between the filter medium particles are filtered, which is between the surface of the filter medium particles or the fine particles previously attached thereto and the fine solid particles. It is said that it is based on the occurrence of a physical adsorption action (as its cause, various factors such as an electromagnetic force and an adsorption force due to viscosity are considered).

However, such an adsorption action does not always occur, and depending on the interfacial conditions between the fine particles and the surface of the filter medium particles or the fine particles which have been previously adhered thereto,
The adsorption may not occur.

That is, in sand filtration, whether or not fine particles can be filtered is not always compensated.

On the other hand, in sand filtration, coarse solid particles larger than the intervals of fine particles naturally deposit, but such sedimentation causes clogging of sand, and the adsorption action as described above is also hindered. It may occur and the original function may not be exhibited.

On the other hand, in order to overcome the above-mentioned drawbacks of sand filtration, it has been proposed to use a filter mesh having a mesh of a size capable of filtering fine particles. In this case, coarse particles are inevitably filtered, and the mesh of the mesh is clogged, and the filtering action may be rapidly lost.

Moreover, no matter what kind of fine mesh screen is used, it is extremely insufficient to carry out the filtering action of fine suspended solid particles of 5 microns or less, pollutant substances for purification and the like. .

[0009]

DISCLOSURE OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of the prior art, and solid particles ranging from coarse particles to ultrafine particles, fine colloid particles, and dissolved pollutants. It is an object of the present invention to provide a filtration device that enables filtration of the above and is less likely to cause clogging.

[0010]

[Means for Solving the Problems] In order to solve the above problems,
As shown in FIGS. 1 and 2, the constitution of the present invention comprises a coagulation separation layer 1 containing a filtration bag 11 made of a single filter net of highly non-adhesive synthetic resin, and a plurality of filter nets connected thereto. 21
Are sequentially arranged such that the larger meshes are on the lower side and the smaller meshes are on the upper side.

[0011]

As is apparent from the above description of the structure, the present invention is a coagulating sedimentation layer 1 using a single filter net made of a highly non-adhesive synthetic resin and a filter 2 having a plurality of filter nets arranged therein. It is characterized in that it is used in combination with the coagulation-sedimentation layer 1 to agglomerate and precipitate fine suspended solid particles and colloidal particles having a particle size of 5 μm or less in advance, and also dissolved pollutants. This is because the solid particles other than those mentioned above are filtered by the filter.

In FIG. 1, in the raw water tank 3,
The aggregating agent is dispersed based on the action of the stirring screw 6 rotated by the motor 7 or the like, and the water containing the aggregating agent is
It is sent to the stirring tank 4 via the pump 5, and the aggregating agent is sufficiently agitated with water in the agitating tank 4 by the agitating screw so that the aggregating agent is dissolved in water.

Here, a single filter net made of a highly non-adhesive synthetic resin will be described.

Generally, in the coagulation / separation layer, inorganic and polymer coagulants are dropped to agglomerate fine solid particles and dissolved pollutants to precipitate in the coagulation / separation layer. Move to the bottom. In FIG. 2, 1
Reference numeral 3 denotes a sheath cylinder, which serves to hold the filter net 11 in a closed state, and 14 denotes a filter slag storage chamber, which is a portion for storing the precipitate generated in the coagulation / separation tank.

On the other hand, as shown in FIG. 2, a filter net 11 is formed on the bottom and side walls of the coagulation / separation tank 1.
Permeates except the aggregated precipitate.

By the way, when an ordinary filter net is used, agglomerated precipitates are very likely to adhere to the filter nets constituting the inner wall and the bottom of the side surface of the coagulation / separation layer, which causes clogging during the filtering operation. At the same time, it is difficult to remove the deposit once attached.

In such a case, it is possible to prevent said sticking if the inner side wall and the bottom filter mesh are highly non-sticky.

The inventors of the present invention have used such a highly non-adhesive synthetic resin as PKFE (4 flucca ethylene resin) or PFE.
FA (4-Fucca ethylene-Fucca fluoroalkyl vinyl ether copolymer), FBE (4-Fucca ethylene-
It has been experimentally confirmed that 6-Fucca-propylene copolymer resin) is more convenient than other resins.

Moreover, the present invention requires that the filter mesh forming the inner side wall and the bottom of the settling layer is a single layer, but in the case of multiple layers, when agglomerated precipitates adhere, they are separated. Is difficult.

On the other hand, in the filter of the present invention, when raw water is made to flow from the lower side to the upper side, particles having a relatively large particle size are filtered by a filter mesh having a large mesh on the lower side to obtain a relatively small particle size. The particles having a diameter are filtered through a small mesh having an upper mesh, and are filtered while being dispersed in each of the meshes depending on the size of the particle, so that rapid clogging such as using one mesh occurs. Absent.

In addition, in the case of washing, by running water from the upper side to the lower side, the solid particles adhering to each filter mesh easily pass through the screen through the mesh below the particle size of the solid particles. Then it moves downwards and is eliminated.

[0022]

[Examples] As a method for forming the filter net of the precipitation layer of the present invention, it is possible to form the thread of the highly non-adhesive synthetic resin by monofilament yarn weave, plain weave or twill weave. It is also possible to adopt a configuration in which the mesh portion and the other portion as shown in FIG. 3 are molded into a planar shape.

However, the filter mesh used in the filter of the present invention is not necessarily limited to the highly non-adhesive synthetic resin as in the above specific examples.

[0024]

As described above, according to the present invention, fine particles of 5 μm or less and dissolved pollutants are preliminarily precipitated in the sedimentation layer by the coagulant and separated, and then a plurality of filter nets are additionally provided. With the above-described filter, water or other low-viscosity liquid can be almost completely filtered by filtering other solid particles.

Moreover, as described above, the use of the filter mesh made of the synthetic resin of the highly inviscid material prevents the deposit of the deposit on the inner side wall and the bottom of the deposit layer, and prevents clogging due to this. Can be prevented.

On the other hand, in the above-mentioned filtering machine, at the stage of filtering by passing the raw water from downward to upward,
Solid particles are dispersed and stored in each filter net, and clogging is less likely to occur, and extremely rapid washing is possible in the washing step of passing the filter retention water from the upper direction to the lower direction.

As described above, the present invention can provide a filtration device having various advantages by combining a coagulation-sedimentation layer using a new material with a filtration device that is already formed, and its value is tremendous.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an outline of the configuration of the present invention.

FIG. 2 (a): Plan view showing the bottom of the precipitation layer of the present invention.

FIG. 2B is a sectional view showing a side section of the precipitation layer of the present invention.

FIG. 3: Plan view showing a specific example of the shape of the filter mesh used for the sedimentation layer.

[Simple explanation of the sign]

 1: Coagulation / separation tank 11: Filter mesh forming the inner side wall and bottom of the coagulation / separation tank 12: Aggregated sediment receiving and intercepting device 13: Sheath cylinder 14: Filter stagnation chamber 2: Filter 21: Filter constituting filter Net 22: Backwash water receiving coarse collector 23: Medium water tank 3: Raw water tank 4: Stirring tank 5: Pump 6: Stirring screw 7: Motor

Claims (2)

[Claims] 1. A cohesive separation layer containing a bag for filtering with a single filter mesh of a highly non-adhesive synthetic resin, and a plurality of filter meshes connected to the coagulation separation layer are sequentially arranged such that the larger mesh has a lower side and the smaller one. A filtration device comprising a filtration machine in which the filters are sequentially arranged so as to face upward. 2. PKF as a highly non-adhesive synthetic resin
It is recommended to use any one of E (4 flucca ethylene resin), PFA (4 flucca ethylene-fucca fluoroalkyl vinyl ether copolymer), FBE (4 flucca ethylene-6 flucca propylene copolymer resin) or a combination thereof. The filtering device according to claim 1, which is characterized in that.