JPS5920334Y2 - Continuous "filtration" device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a continuous filtration device that performs both filtering treatment and pH cleaning without circulating the furnace material.

Conventionally, in general filtration equipment, filtration and pH of the treated liquid are
Cleaning was treated as a separate operation.

For this reason, the filtrate cannot be used when cleaning the furnace material, and the shortage of filtrate during the cleaning time has been compensated for by operating a standby device.

As a device that can solve this problem and perform continuous operation, JP-A-52-111062 and JP-A-53
A device described in Japanese Patent No. 92369 has been proposed.

First, the outline of this device will be explained along with its operation along with FIG. 1. Inside the filtration tank 1, a furnace material layer is formed of a furnace material 2 made of sand or the like.

This furnace material layer has a plurality of upwardly directed inflow pipes 3, 3...
... is provided, and above the inflow pipe 3, an annular stock solution distribution amount 4 having a chevron-shaped cross section is provided.

The stock solution A to be filtered flows from the inflow pipe 3 into the slough layer while being uniformly dispersed by the distribution amount 4.

At this time, a flocculant is added as necessary depending on the type, properties, and degree of pretreatment of the stock solution.

Further, as the furnace material 2, sand having a thickness of about 0.6 mm to 2.0 mm is usually used.

The suspended solids in the raw solution that has passed through the distribution volume 4 are removed when passing through the furnace material layer, becoming a clean filtrate, which is temporarily stored in the upper part of the furnace material layer, and the overflow water is collected as filtrate water B. Gutter 5
Water is collected through.

While this filtration action is taking place, as will become clear from the action described below, the pH 2 gradually moves downward and passes through the gap between the furnace material moving umbrella 6 and the bottom inclined surface of the filtration tank 1. and reaches the center bottom of the filtration tank 1.

On the other hand, in the center of the filtration tank 1, a vertical cleaning pipe 7 is disposed upward from the bottom thereof.

The bottom of this cleaning tube 7 (or the center if necessary)
An air feed pipe 8 is connected to the air supply pipe 8, from which compressed air Ai is blown.

As a result, the furnace material 2 that has reached the center bottom is airlifted together with the air and rises inside the cleaning pipe 7.

At this time, the furnace material is subjected to a vigorous stirring action by air and water, and the suspended solids trapped in the furnace material 2 are separated from the furnace material 2.

The suspended solids then overflow from the top of the cleaning pipe 7 together with the cleaning water, and are discharged as cleaning waste water C through the drainage gutter 9 to the outside of the apparatus.

On the other hand, the cleaned furnace material falls under its own weight through the gap between the cleaning outer tube 10 provided on the upper outer periphery of the cleaning tube 7 and the cleaning tube 7, and then falls above the resin layer. Cleaning pipe 7
The furnace material is returned onto the furnace material layer along the divergent furnace material distribution amount 11 fixed at .

Here, while the furnace material passes through the cleaning outer pipe 10, due to the water level difference between the overflow water level of the Fuchikasui B and the drainage level to the cleaning drainage gutter 9,
The cleaning liquid (cleaning liquid) rises through the gap between the outer cleaning tube 10 and the cleaning tube 7 in opposition to the descent of the furnace material, as shown by arrow X, and comes into contact with the side materials to clean them.

Thus, the above-mentioned apparatus is extremely superior in that it can perform continuous filtration without interrupting filtration to clean the furnace material.

However, in actual cases where there is overflow of treated water at a sewage treatment plant, it has been found that there are two main drawbacks.

The first point is that the filtration area is not sufficient due to the furnace material dispersion amount 11.

As shown by the arrow Y in the same figure, the flow of lachrymal fluid rises near the wall of the tank 1 while avoiding the dispersion amount 11. As a result, the zone Z becomes a dead space, and the actually effective furnace material is the filling furnace. It is about % of the wood.

Therefore, the actual slough speed is approximately twice the design speed, and the quality of the slough liquid is correspondingly lower than the designed one.

The second difficulty is that with this type of sand filter, most of the suspended solids in the stock solution are removed by the sieving action of the side materials, but the suspended solids that remain in the P solution pass through the sieves. Turbid substance F
This also leads to a decrease in tear fluid crystallinity.

This invention was proposed to address the above-mentioned difficulties.
The purpose is to effectively utilize the filtration area and ensure the capture of suspended solids.

The present invention will be explained below with reference to an embodiment shown in FIG.

The same reference numerals as in FIG. 1 are given to the same parts.

In the present invention, if the furnace material 2 is permeable, that is, the furnace material 2 is sand as described above, the amount of the furnace material dispersed is preferably 1 to 1.
The net-like dispersion amount is 110, which has through holes (sieve mesh) of 0 mmφ, more preferably 1 to 2 mmφ throughout.

If the size of the through hole is less than 1 mmφ, the passage of the filtrate from below will not necessarily be smooth, and it will also be difficult to pass through the filter medium 2 from above.

As a result, the dead space under the dispersion amount 110 is not sufficiently eliminated, and the distribution of the filter medium 2 is biased towards the periphery of the filter medium layer.

On the other hand, if the size of the through hole exceeds 10 mmφ,
The filter medium 2 is supplied onto the filter medium layer locally at the center, which prevents uniform distribution.

In addition, it becomes difficult to trap suspended substances in the filtrate in the pores as described below, allowing the suspended substances to remain in the filtrate and reducing the crystallinity of the filtrate.

As a result, the lachrymal fluid also passes through the through holes with a dispersion amount of 110, and the entire filtration area of the furnace material can be effectively utilized without creating a dead space unlike in the conventional case.

In addition, the suspended solids F that flowed upward through the furnace material 2 are captured in the perforations of the dispersion amount 110 and are not mixed into the polishing water B, greatly reducing the amount of suspended solids that flow out. The quality of filtrated water is improved.

Note that even if the suspended matter remains in the pores, it is extremely unlikely to impede the flow of the P liquid.

On the other hand, although a net-like body was used as the dispersion amount 110 in the above example, it is of course possible to use a punched metal or the like.

Further, the shape and arrangement of the through holes themselves are selected as appropriate.

In addition, although a through hole is shown in the dispersion amount 11 in Fig. 1, this hole is about 18 to 20 mm in diameter and is used exclusively for the drop of the village, and its function is completely different from the through hole of the present invention. .

Furthermore, in addition to sand, gravel, activated carbon, coal, or plastic granules can also be used as the furnace material.

As described above, according to the present invention, it is possible to make effective use of the filtration area and reliably capture suspended substances.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a conventional device, and FIG. 2 is a schematic sectional view showing an embodiment of the device of the present invention. 1...Filter tank, 2...Furnace material, 3...
...Inflow pipe, 7...Cleaning pipe, 10...
・Cleaning outer tube, 110... Furnace material dispersion amount.

Claims (1)

[Scope of utility model registration request] 0°6 to 2.0° to capture suspended matter in the liquid to be treated.
A filter tank has a filter layer composed of granular filter media with a diameter of 0 mm, a filtrate reservoir formed above the filter layer and containing the filtrate after passing through the filter layer, and a filter tank that opens upward into the filter layer and stores the liquid to be treated in the filter layer. Inflow means for flowing into the layer; has a structure that extends vertically from the bottom of the filter medium layer in the center of the filtration tank and communicates with the outside air above, and takes in the filter medium to be cleaned from the bottom by the air lift A filter medium cleaning device that separates suspended matter captured by the filter medium by stirring during rising, and washes the separated filter medium while bringing it into countercurrent contact with the filtrate;
A dispersion umbrella disposed between the filter medium layer and the filtrate storage part, which spreads toward the end and returns the filter medium after washing while distributing it onto the filter medium layer, and has a through hole of 1 to 10 mmφ over the entire surface of the dispersion umbrella. 1. A continuous filtration device, characterized in that a washing filter medium is supplied onto a filter medium layer under a dispersion umbrella, and a filtrate flow path from below the dispersion umbrella to a filtrate storage section is formed.