JPH055922Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention separates and removes suspended solids (hereinafter abbreviated as "SS") contained in water and sewage water, industrial water, industrial wastewater, etc., and clarifies them. This relates to a clarifying filtration device.

[Problems to be solved by conventional techniques and ideas]

Clarification filtration technology is the oldest water treatment technology and is still widely used to this day. In the past, it was mainly used for relatively clear water such as waterworks and industrial water, but in recent years it has become commonplace to treat wastewater such as sewerage and industrial wastewater.

The removal mechanism in clarifying filtration is explained as sieving between filter media particles, precipitation on filter media particles, coagulation with filter media particles, etc., and naturally, the filter media plays an important role. In general, sand or anthracite is often used as a filter medium, and under appropriate usage conditions, it rarely causes major problems and is highly rated.

However, in the conventional clarifying filtration,
If the appropriate usage conditions are exceeded, e.g.
mg/, the filter media layer will quickly become clogged and must be backwashed frequently.
In extreme cases, the amount of backwash water may be greater than the amount of treated water. In addition, when performing high-speed processing, it is difficult to perform high-speed processing at LV20m/h or higher because filtration resistance increases as the filtration speed (hereinafter abbreviated as "LV") increases, and SS leaks into the treated water. Ta.

In order to compensate for these shortcomings, various methods have been proposed, such as continuously moving the filter medium (Japanese Patent Publication No. 59-38006), increasing the particle size of the filter medium, and even changing the material of the filter medium. is being attempted. However, the current situation is that no fundamental solution has been found, and even if the raw water SS happens to be high and high-speed processing is possible, sufficient cleaning may not be possible or complicated operations are required for cleaning. Serious problems remain, such as the need for large amounts of equipment and equipment.

Furthermore, in the case of downward flow filtration and upward flow filtration, the installation space for equipment is determined by the filtration area, and as the amount of water to be treated increases, a wider installation space is required. On the other hand, horizontal flow filtration has the advantage that the filtration area can be larger in the vertical direction than vertical flow filtration such as downward flow and upward flow filtration, so the installation area is smaller for the same amount of water to be treated. .

However, even in horizontal flow filtration, sand, anthracite, etc. are used as filter media, so
The continuous filtration method has not been sufficiently adapted to deal with highly turbid raw water, and a continuous filtration method has been adopted in which a part of the polluted filter medium is lifted up by an air lift effect and stirred to separate the sludge. In the case of such continuous filtration, it is necessary to fluidize a portion of the filter medium, so that the filter medium is not in a completely fixed bed but in a slightly suspended state. Therefore,
Limits on raw water turbidity regarding turbidity removal (up to 50~
60ppm), filtration speed limit (maximum around 250m/d)
etc. were hot.

This invention solves the above problems by fundamentally reviewing conventional filtration technology, and enables high-turbidity raw water to be treated quickly, stably, and easily, while greatly reducing the installation space. The object of the present invention is to provide a clarifying filtration device that has the following properties.

[Means for solving problems]

The present invention, as a means to solve the above problems, holds a sponge filter medium in a tank with a porous body,
A raw water distribution section is formed on a side surface of the porous body, and a treated water collection section is formed on the opposite side surface, and a wash water inflow pipe is connected to one of the raw water distribution section or the treated water collection section, and to the other. The present invention provides a clarification filtration device characterized in that washing drain pipes are connected to each other so that the flow of raw water and washing water can be switched, and an aeration device is provided below the sponge filter medium.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, a rectangular tank body 1
An upper perforated plate 2 and a lower perforated plate 3 are installed inside.
A sponge filter medium 5 is held in a filled state in a space partitioned by these and the side perforated plates 4, 4. A water-permeable material such as a net can also be used for each of the perforated plates, and for the purpose of holding the sponge filter medium 5, the sponge filter medium 5 divided into small pieces can be used.
When using a filter, the opening should be designed to prevent the sponge filter from flowing out. In addition, each of the perforated plates has only the part filled with the sponge filter medium 5, and the other parts are connected to the tank body 1 by a flat plate 6 as shown in the illustrated example, so that water can be passed through by horizontal flow during the filtration and cleaning processes described later. It is preferable to avoid short circuits.

The sponge filter media 5 filled and held in each of the perforated plates may be a block of sponge corresponding to the filtration volume, a mat-shaped sponge divided into multiple layers, or a regular or irregular shape cut into a size larger than the opening of the perforated plate. Standard-shaped sponges and thin sheet-shaped sponges rolled into rolls are used.

A raw water distribution part 7 is formed between one side of the side perforated plate 4, for example, the right side side perforated plate 4 in FIG. 1, and the tank wall.
A treated water collection section 8 is formed between the side perforated plate 4 on the opposite left side and the tank wall, and the tank wall of the raw water distribution section 7 is connected to a raw water inflow pipe 9 having a raw water inflow valve _V1 . A plurality of inflow nozzles 10 are arranged above and below for the purpose of uniform inflow, and a treated water outflow pipe 1 having a treated water outflow valve _V2 is provided on the tank wall of the treated water collection section 8.
A plurality of outflow nozzles 12 connected to each other are arranged above and below for the purpose of uniform outflow.

Further, on the downstream side of the raw water inflow valve V ₁ of the raw water inflow pipe 9, there is a wash water inflow pipe 13 having a wash water inflow valve V ₃ .
are connected, and the treated water outflow valve V ₂ of the treated water outflow pipe 11
A wash drain pipe 14 having a wash drain valve V ₄ is connected to the upstream side of the pipe, but in contrast, the wash water inflow pipe 13 is connected to the treated water outflow pipe 11 and the wash water drain pipe 14 is connected to the raw water inflow pipe 9. May be connected. Note that there is a branch pipe 1 on the upstream side of the wash water inflow valve V3 of the wash water inflow pipe 13.
A cleaning water nozzle 16 is connected to the upper tank wall of the raw water distribution section 7 through the upper cleaning valve _V5 .
A branch pipe 17 is connected to the downstream side of the wash drain valve V ₄ of the wash drain pipe 14, and the wash drain provided on the upper tank wall of the treated water collection section 8 is connected to the wash drain pipe 14 via the upper drain valve V ₆ . It is connected to a nozzle 18 for use.

Furthermore, a diffuser 19 such as a diffuser tube or a diffuser plate for air cleaning is provided below the lower perforated plate 3, and is connected to an air source (not shown) via an air inlet valve _V7 .

Therefore, the raw water flows from the raw water inflow pipe 9 to the raw water inflow valve.
It evenly flows into the raw water distribution part 7 in the tank through V ₁ and the inflow nozzle 10, passes through the side perforated plate 4 in a horizontal flow, passes through the sponge filter medium 5, is filtered, and flows into the treated water collection part 8. After the water is collected, it flows out from the treated water outflow pipe 11 via the outflow nozzle 12 and the treated water outflow valve _V2 .

If this type of filtration is continued for a long time, the filtration resistance will increase, and in some cases, SS will begin to leak into the treated water, similar to conventional filtration equipment. In such a case, filtration is performed in the middle and the sponge filter medium 5 is washed. For cleaning, close the raw water inflow valve V ₁ and the treated water outflow valve V ₂ , open the cleaning water inflow valve V ₃ and the cleaning water drain valve V ₄ , and let the cleaning water flow in from the cleaning water inlet pipe 13. The cleaning water is the same as the raw water. During this cleaning process, the air inflow valve _V7 is opened and the cleaning air is blown out from the air diffuser 19, discharging the fine particles between the filter media. The SS trapped in the filter material is removed by the passage of air and the resulting vibrations. The cleaning water washes out the SS separated from the sponge filter medium 5 by this air cleaning, but the SS is also discharged from the upper part of the sponge filter medium 5 by air cleaning. was discharged to the top of this filter medium.
In order to flush out the SS, a part of the wash water is sent from the branch pipe 15 and the upper wash valve _V5 to the wash water nozzle 1.
SS led into the tank through step 6 and discharged onto the top of the filter media.
Upper drain valve from cleaning drain nozzle 18 with minutes
Discharge via V ₆ and branch pipe 17.

In this case, if the raw water has a high turbidity, clear treated water must be used as the cleaning water, but if the raw water has a relatively low turbidity, the raw water can be used as the cleaning water.

3 and 4 show another embodiment of the present invention, in which the tank body 1 is a circular tank (or polygonal tank), an upper perforated plate 2, a lower perforated plate 3, and a side perforated plate. 4 is formed into a hollow cylindrical shape and arranged concentrically in the tank, and the hollow part serves as the raw water distribution part 7, into which the inflow perforated pipe 20 connected to the raw water inflow pipe 9 is inserted, and the side perforated plate A plurality of outflow nozzles 12 are arranged evenly on the tank wall with the outer periphery of the tank 4 serving as a treated water collecting section 8, and its operation is similar to that of the embodiment shown in FIGS. 1 and 2.

Furthermore, as another embodiment of the present invention, contrary to the examples shown in FIGS. 3 and 4, an inflow nozzle is arranged on the tank wall with the outer periphery of the side perforated plate 4 as a raw water distribution part, and the hollow part is treated. It can also be modified to insert a water collection porous pipe inside as a water collection part.

In this way, the present invention uses a sponge as a filter medium, which has a far superior capture amount of SS in raw water compared to conventional methods, and effectively utilizes the filter medium to perform volumetric filtration rather than surface filtration during filtration. By adopting horizontal filtration, the installation space is greatly reduced. In addition, the filter medium is cleaned using a combination of water and air, allowing air to flow in from the bottom of the filter medium, allowing the SS trapped within the filter medium to be easily peeled off from the filter medium through the passage of fine air between the filter mediums and the resulting vibrations. , drain from the filter media with washing water.

Furthermore, normally, the cleaning water flows in the same direction as the air (upward flow) to cause the SS component to flow out from inside the filter media, and the SS separated from the filter media located at the bottom is
The washing time requires time for the water to flow out from the top of the filter media, but in the case of the horizontal flow filtration of this invention, the vertical cross-sectional area of the filter media layer is larger than the horizontal cross-sectional area of the filter media layer, and the washing water flows into the filter media layer. On the other hand, since the water flows horizontally, the cleaning time is also shortened. In addition, regarding the required amount of cleaning air, if we compare the vertical flow of the conventional method and the horizontal flow of the present invention, we can see that: Conventional filtration number Filtration area of the present filtration device 5 m x 5 m = 25 m ² Same left filtration layer thickness 600 mm Same left cleaning Required area
5m x 5m = 25m ² 5m x 0.6m = 3m ² Required air volume ratio 25/3 = 8.3:1, and the amount of air required by this invention is greatly reduced compared to the conventional method.

[Effect of idea]

As described above, the present invention has extremely beneficial effects as listed below.

Not only can it handle highly turbid raw water using sponge filter media, but the use of horizontal flow filtration also greatly reduces installation space.

By flowing the cleaning water horizontally, the inside of the filter medium can be
SS content is discharged in a short time, reducing cleaning time.

Regarding the amount of washing water, conventional sand filtration requires the amount of water necessary to expand the sand layer, but in the present invention, since a sponge is used as the filter medium, the washing water is mainly used for air cleaning, and the washing water is used only for discharging SS. Therefore, it requires less than the conventional method.
Even if the washing water passage area increases compared to the vertical flow method, the amount of washing water will not increase significantly.

Since the horizontal cross-sectional area of the filter layer can be made smaller than the vertical cross-sectional area, the amount of air required for air cleaning is greatly reduced, and the capacity of the attached compressor and blower can be small, resulting in energy savings.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a longitudinal sectional view showing another embodiment of the invention, and Fig. 4 is a plan view thereof. . 1... Tank body, 2... Upper perforated plate, 3... Lower perforated plate, 4... Side perforated plate, 5... Sponge filter material, 6... Flat plate, 7... Raw water distribution section, 8... Treatment Water collection section, 9... Raw water inflow pipe, 10... Inflow nozzle, 11... Treated water outflow pipe, 12... Outflow nozzle, 13... Washing water inflow pipe, 14... Washing drain pipe, 15, 17... ...Branch pipe, 16...Washing water nozzle, 18...Washing water nozzle, 19...Aeration device, 20...Inflow porous pipe, _V1 ...Raw water inflow valve,
V ₂ ... Processed water outflow valve, V ₃ ... Washing water inflow valve, V ₄
...Washing drain valve, V ₅ ... Upper washing valve, V ₆ ... Upper drain valve, V ₇ ... Air inflow valve.

Claims (1)

[Claims for Utility Model Registration] (1) A sponge filter medium is held in a tank by a porous body, and a raw water distribution section is formed on the side of the porous body, and a treated water collection section is formed on the opposite side. A wash water inflow pipe is connected to one of the raw water distribution section or the treated water collection section, and a wash water drain pipe is connected to the other, so that the passage of raw water and wash water can be switched, and the sponge filter medium A clarifying filtration device characterized by having an air diffuser installed at the bottom. (2) The clarifier according to claim 1, wherein the porous body has a hollow cylindrical shape, and the hollow part is the raw water distribution part and the outer peripheral part is the treated water collection part. Filtration device. (3) The clarifier according to claim 1, wherein the porous body has a hollow cylindrical shape, and the outer peripheral part is the raw water distribution part and the hollow part is the treated water collection part. Filtration device.