JPH07299309A - Filter apparatus - Google Patents

Abstract

PURPOSE:To provide a filter apparatus capable of treating a large amt. of raw water by simple operation in spite of a small size and effectively removing respective impurities. CONSTITUTION:A slide member 12 made freely movable in the longitudinal axis direction of a cylindrical body 10 by a cylinder 11 and having a large number of through-holes is provided in the cylindrical body 10 having an inflow port 10a of water to be treated at one end part thereof and a discharge port 10b of treated water at the other end part thereof and a large number of filter cloths 14, 14... filtering raw water flowing in from the through-holes of the slide member 12 are provided on the side of the treated water discharge surface of the slide member 12.

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 treatment of dredging surplus water in lakes and marshes, aftertreatment of a sedimentation tank, purification of water and treatment of tap water.

[0002]

2. Description of the Related Art In recent years, in closed water areas such as rivers, lakes and marshes, eutrophication phenomenon has occurred due to a gradual increase in nutrient salts such as nitrogen and phosphorus, which has become a serious problem. In eutrophic lakes, etc., organic matter produced in water is oxidized by dissolved oxygen in the lake water, so the amount of dissolved oxygen decreases in the bottom layer of eutrophic lake, and sometimes harmful hydrogen sulfide is contained. There is a problem such as becoming. Also, when harmful algae and plankton occur especially in the summer, they later decompose and give off a bad odor, deteriorating the surrounding environment, consuming dissolved oxygen in water, and causing harmful effects on hydrogen sulfide and other harmful substances. There is a problem such as generating something.

As a measure for solving these problems, a method of dredging bottom mud is currently effective, and the number of construction works is increasing year by year. In this case, the nutrient components necessary for the above-mentioned microbial propagation are nitrogen and phosphorus, and if the residual water generated during dredging of the bottom mud is discharged as it is, it will not be a fundamental solution for lake purification. A filter device such as a belt press is used to remove nitrogen, phosphorus, etc. together with the dehydrated cake.

[0004]

However, when a belt press is used as the filtering device, a peripheral equipment such as a slurry tank, a slurry pump, a hydraulic unit, a filter cloth device, etc. are required, and the size of the device becomes large as a whole. Looking at the water quality data of the treated water in the past, the removal rate of phosphorus can be secured in the order of 90%, but the nitrogen removal capacity is low at about 15 to 45%.

On the other hand, generally, in the coagulation sedimentation treatment of polluted water or the biological treatment, the treated water is finally discharged after being solid-liquid separated in the sedimentation tank. In this case, the amount of suspended solids (SS) will be small if the treatment is in good condition, and no problem will occur if discharged. However, if the treatment is insufficient and a large amount of suspended substance is contained, rivers, etc. It is also a cause of soiling.

On the other hand, with the recent increase in social activities, the inflow load of pollution sources and the like has increased, and the deterioration of environmental water such as rivers and lakes has become a problem. Therefore, minute sediments contained in water, pollutants such as algae and plankton are major obstacles in using public water areas.

Further, with the progress of water pollution, the water quality of the water source as clean water is deteriorating, and it is becoming difficult to secure the water source. For this reason, in a water purification plant, much cost and labor are required more than ever before to take measures for water quality purification such as adding an aggregating agent to remove impurities.

Therefore, the main problem of the present invention is that it is suitably used for filtering treatment of dredging surplus water in lakes and marshes, post-treatment of sedimentation tank, purification of water and treatment of tap water. Moreover, the present invention provides a filtration device that is small in size, can process a large amount of raw water with a simple operation, and can effectively remove each impurity.

[0009]

[Means for Solving the Problems] The object is to provide a cylinder body having a raw water inlet on one end side and a treated water discharge port on the other end side by means of a reciprocating control drive means. And a filter for filtering raw water flowing from the through holes of the sliding body to the treated water discharge surface side of the sliding body, the sliding body being movable in the longitudinal axis direction of the sliding body. It can be solved by having a lot of cloths.

In this case, as the filter cloth, a strip-shaped or bag-shaped filter cloth is preferably attached like a blind. Also,
It is desirable that a partition plate having a large number of through holes is provided on the treated water discharge end side of the cylindrical body. Further, by providing a washing water inlet for backwashing on the discharge end side of the treated water of the cylindrical body and a washing water discharge port for backwashing on the inflow end side of the treated water, for example, a feed path for raw water The filter cloth can be easily washed by switching between the above and the other side so that the filter cloth flows from the opposite side.

As the material of the filter cloth, various materials can be used. Especially when a plain woven cloth made of natural fibers or chemical fibers is used, the filter apparatus of the piston type compression system according to the present invention is used. It is suitable, and especially the ability to remove impurities is improved.

[0012]

In the case of the filtering device according to the present invention, a cylindrical body having an inlet and an outlet at each end, and a sliding body which moves inside the cylindrical body and is provided with a large number of filter cloths attached to it like a blind. It is basically composed of Therefore, it is very simple in terms of equipment, and since the water to be treated contained in the cylinder is squeezed and filtered at a stretch, it is possible to perform a large amount and efficient filtration of raw water though it is a batch process. . Also,
By providing a partition plate with a large number of through holes on the treated water discharge end side inside the cylinder, the treated water after filtration can be effectively discharged without blocking the discharge port with a compressed filter cloth. Can be drained from.

[0013]

EXAMPLES The present invention will be described in detail below based on examples.
In FIG. 1, raw water, which is water to be treated, that has been transported from lakes, sedimentation tanks, etc. is temporarily stored in a raw water receiving tank 2. The stored raw water is fed by a pump 3 through a three-way valve 4 to a feed path R.
Fed to a filtration device 1 according to the present invention by _one. The raw water supplied to the filtration device 1 is removed from the suspension, nitrogen, and phosphorus contained in the raw water here, and once stored in the storage tank 9 as treated water, and then discharged or refiltered into a river or the like. It is processed. Since COD (chemical oxygen demand) and BOD (biochemical oxygen demand) are significantly reduced in the treatment through the filtration device 1, when the treated water is discharged to a raw water supply source, Suspension in source, nitrogen,
Besides removing phosphorus, COD and BOD can be reduced.

The filtering device 1 according to the present invention will be described below in detail with reference to FIG. The filter device 1 has a raw water inlet 10a and a wash water outlet 10c formed on one end side, and a treated water outlet 10b and a wash water inlet 10d on the other end side.
In the cylindrical body 10 in which is formed a slide body 12 whose reciprocating motion is controlled by a cylinder 11 and a large number of through holes are formed. Here, instead of the cylinder 11, a motion mechanism that changes a rotary motion into a reciprocating motion by a link may be adopted. Further, other motion mechanism may be used. In short, any driving means for reciprocating the sliding body 12 along the longitudinal axis of the cylindrical body may be used.

A large number of filter cloths 1 are provided on the treated water discharge surface side of the slide body 12 (the side opposite to the cylinder arrangement side of the slide body 12).
4, 14, ... Are hung in a blind shape, and the raw water that has passed through the control valve 5 and is supplied to the filtering device 1 flows into the filter cloth disposing space P after passing through the through holes of the sliding body 12. By pressing with the sliding body 12, various impurities are brought into contact with the filter cloths 14, 14 ... Or permeate the filter cloths 14 ,.
4, 14, ...

As the material of the filter cloth 14, in addition to natural materials such as cotton cloth, wool cloth and linen cloth, nylon, acrylic,
Chemical fibers such as polyester and polyvinyl chloride are used.

The weave design includes plain weave, twill weave, broken twill weave, satin weave and the like. Especially, in the case of plain weave, the mechanical strength is the largest and the slag removing operation is easy, and it will be described later. As shown in the experimental example, when used in the filtration device of the present application,
Most effectively exerts its filtering function. In addition, the filter cloth 14
The length of is preferably equal to or slightly shorter than the length of the tubular body, specifically, 0.8 to 1.0 times the length of the tubular body. Can be a single strip-shaped filter cloth, or a bag-shaped filter cloth in which the front and back surfaces can be separately used as a bag to improve the capturing ability. As an example of an attachment mode of the filter cloth 14, as shown in FIG. 4, a plurality of strip-shaped or bag-shaped filter cloths 14, 1
A bundle of 4 ... Is attached and attached to the sliding body 12 by the suspending member 15.

On the other hand, a partition plate 13 having a large number of through holes is fixedly arranged on the outlet side of the treated water in the cylindrical body 12, and the raw water is placed in the filter cloth arrangement space P. When the cylinder 12 is gradually extended in the state where the water is stored, the filter cloths 14, 14 ... Are compressed by using the partition plate 13 as an abutment body, and the raw water is filtered as shown in FIG. Filtered by contact or permeation. In this case, the raw water is continuously supplied according to the extension state of the cylinder 11,
By generating a back pressure on the back surface side of the sliding plate 12, it is possible to prevent the backflow of raw water. The treated water filtered by the filter cloths 14, 14 ... Then passes through the through holes of the partition plate 13 and is guided to the storage tank 9 by the feed passage R ₂ on the control valve 8 side. Next, in order to continue the filtration process, the step of accommodating the raw water in the filter cloth disposing space P and the step of compressing the filter cloth 14 are alternately repeated by the reciprocating motion of the sliding body 12 by the cylinder 11. By this repeated operation, the raw water filtering process is performed batchwise. A plurality of filtering devices 1 are provided according to the processing capacity. Here, the amount of movement of the slide body 12 by the cylinder 11, that is, the slide body 1
Distance between 2 and partition plate 13 (hereinafter referred to as filter layer thickness)
Although the filtration pressure is adjusted by the filter cloth, if the filtration pressure is too high (the filter layer thickness is small), even fine particles can be filtered by the filter cloth 1.
It is preferable that the thickness of the filter layer is approximately 10 to 25 cm because it will pass through No. 4 and cause turbidity. Further, it is preferable to 1kg / cm ² ~3kg / cm ² approximately in filtration pressure.

The backwashing for preventing clogging of the filter cloths 14, 14 ... After performing the filtering process for a predetermined time is performed as follows. First, the cylinder 11 is contracted to extend the filter cloths 14, 14 ... (The state shown in FIG. 1), the control valve 5 and the control valve 8 are closed, and the control valve 6 and the control valve 7 are closed.
With the valve open, the three-way valve 4 is switched to the feeding path R ₃ side. Then, the raw water flows in from the discharge side of the tubular body 10, removes each fine solid content clogged in the filter cloth 14, and is guided to the storage tank 9 through the circulation path R ₄ together with the water flow. here,
Pressure during backwash is preferably set to approximately 0.5kg / cm ² ~1kg / cm ² approximately.

The filtering device according to the present invention has been described above in detail. Next, the result of processing raw water actually contaminated by the filtering device and verifying its filtering performance will be described.

(Experimental Example 1) A cotton cloth was used as the material of the filter cloth 14, and the experiment was conducted twice in total while changing the filter layer thickness. Filtration time was 45 minutes, followed by backwashing for 10 minutes.
The specifications of the filter cloth 14 used in this experiment are as shown in Table 1. Here, the packing density at the time of filtration is determined by the total length of the filter cloth / (the cross-sectional area of the cylinder × the filter layer thickness). The water quality of the raw water supplied to the filtration device 1 is as shown in Table 2.

[0022]

[Table 1]

[0023]

[Table 2]

The results of the above tests are shown in Tables 3 to 5 below. Table 3 shows the transparency, flow rate and pressure difference of the first filtration test, and Table 4 shows the transparency, flow rate and pressure difference of the second filtration test. Table 5 shows the water quality of the treated water in the first and second treatments.

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

To summarize the experimental results, in the first case,
From Table 3, after 10 minutes, the transparency was 100 cm, which was more than expected. However, the flow rate decreased as the transparency increased. Further, in the case of the second time, from Table 4, since the filtration layer thickness was 220 mm, the filtration pressure became insufficient and the transparency became about 19 cm. However, the flow rate is much higher than that of the first result.

Therefore, in actual application, it is desirable to perform a sufficient preliminary test and set the filter layer thickness so that both the transparency and the flow rate are equal to or higher than desired levels.

On the other hand, looking at the removal rate of impurities and the like, as can be seen by comparing the raw water with the first treated water or the second treated water, the removal rate range of each item is about 61. ~ 98
%, Which proves to be sufficient to achieve the original purpose.

(Experimental Example 2) Next, an acrylic plain weave cloth, which is an example of a chemical fiber, was used as the material of the filter cloth 14 for filtration, and the filtration layer thickness was set to 200 mm to carry out a filtration experiment.
Table 6 shows the water quality of raw water and the water quality of treated water after filtration.
Shown in.

[0032]

[Table 6]

From Table 6, the range of the removal rate of each item is approximately 6
It was 7 to 98%, and almost satisfactory results were obtained. In addition, the transparency was 50 cm, which was a good result, and the flow rate was as high as that of Experimental Example 1.

[0034]

As described above in detail, according to the present invention, the apparatus is downsized and a large amount of raw water can be treated by a simple operation. Moreover, each impurity is also effectively removed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a filtration system using a filtration device according to the present invention.

FIG. 2 is a vertical sectional view of a filtration device according to the present invention.

FIG. 3 is a state diagram during filtration of the filtration device.

FIG. 4 is an enlarged detailed view of the attachment portion of the filter cloth.

[Explanation of Codes] 1 ... Filtration device, 2 ... Raw water receiving tank, 4 ... Three-way valve, 5-8 ... Control valve, 9 ... Storage tank, 10 ... Cylindrical body, 11 ... Cylinder, 1
2 ... Sliding body, 13 ... Partition plate, 14 ... Filter cloth

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B30B 9/06 G B01D 29/04 510 E 520 Z 530 D 29/38 510 C 530 B (71) Applicant 391005020 Institute for Natural Resources and Biology Co., Ltd. 1-12-9 Oizumi-cho, Nerima-ku, Tokyo (71) Applicant 594076050 Nippon Kentetsu Co., Ltd. 2-62-2 Otemachi, Chiyoda-ku, Tokyo (72) Inventor Tajima Shohachi 5-chome, Matsuba-cho, Kashiwa-shi, Chiba Prefecture 20-403 (72) Inventor Ina Town 273 Mari, Hakuta-cho, Nogi-gun, Shimane Prefecture (72) Hiroaki Sato 5-47-6 Horikiri, Katsushika-ku, Tokyo (72) ) Keizo Ogura 1-2-7 Koraku, Bunkyo-ku, Tokyo Within Sanshin Construction Co., Ltd. (72) Inventor Moriju Hasegawa 1-12-9 Oizumi-cho, Nerima-ku, Tokyo (72) Inventor Ichihare Funabashi, Chiba Prefecture Yamate 1 chome No. 1

Claims (5)

[Claims] 1. A cylinder having a raw water inlet on one end and a treated water outlet on the other end is movable in the longitudinal axis direction of the cylinder by a reciprocating control drive means. And a plurality of through holes are formed, and a plurality of filter cloths for filtering raw water flowing in through the through holes of the slide body are provided on the treated water discharge surface side of the slide body. And a filtration device. 2. The filtration device according to claim 1, wherein the filter cloth has a strip shape or a bag shape. 3. The filtration device according to claim 1, further comprising a partition plate having a large number of through holes formed on the treated water discharge end side in the cylinder. 4. The wash water inlet for backwashing is provided on the treated water discharge end side of the cylindrical body, and the washwater discharge port for backwashing is provided on the treated water inflow end side. The described filtering device. 5. The filter device according to claim 1, wherein the filter cloth is a plain woven cloth made of natural fibers or chemical fibers.