JP2000062833A - Solid and liquid separating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid and liquid separating device capable of attaining a sufficient filtering area even under a narrow mounting area, capable of providing a sufficient filtering rate and further capable of easily performing its maintenance work. SOLUTION: Two planer filtering members are faced against to each other by a predetermined space. Within a solid liquid separating tank 3 is mounted a filtering device 2 in which a plurality of filter modules having their outer circumferential portions sealingly closed by a frame member are held by a spacer in a predetermined space. The inside part of the filtering modules and the outside part of the solid liquid separating tank are communicated with a water supplying port, and at the same time there is provided a cleaning nozzle 4 for injecting cleaning water toward the filtering surface of each of the filtering modules.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation apparatus, and more particularly to a solid-liquid separation apparatus for separating and removing suspended solids contained in secondary treatment water in a sewage treatment plant. The present invention relates to a solid-liquid separation device optimal for use in advanced processing. 2. Description of the Related Art In sewage treatment, in addition to the conventional secondary treatment, the importance of advanced treatment such as reuse of water resources and creation of a hydrophilic area is increasing. The first step in advanced sewage treatment is
This is removal of suspended solids by filtration, and a rapid filtration method and a microstrainer are generally used. [0003] However, in the rapid filtration method, the filtration speed is limited, it is difficult to make the apparatus compact, and a large area is required. In addition, although the microstrainer has a high filtration speed, the filtration area is only a cylindrical surface immersed in water, so that a large installation area is required when performing a large amount of processing. [0004] Therefore, an object of the present invention is to provide a solid-liquid separator capable of obtaining a sufficient filtration area even with a small installation area, having an excellent filtration speed, and easily performing maintenance. [0005] In order to achieve the above object, a solid-liquid separation device of the present invention faces two planar filter media at a predetermined interval, and seals the outer peripheral portion thereof with a frame material. A plurality of filtration modules are held at predetermined intervals by a spacer and installed in a solid-liquid separation tank, and the inside of the filtration module and the outside of the solid-liquid separation tank are communicated with each other through a water inlet, and the filtration module is directed toward the filtration surface of the filtration module. It is characterized in that a washing nozzle for jetting washing water is provided. 1 to 4 show an embodiment of a solid-liquid separator according to the present invention. FIG. 1 is a system diagram showing an example of installation of peripheral devices of the solid-liquid separator. FIG. 2 is a side view of the filtration unit, FIG. 3 is a plan view of the same, and FIG. 4 is a system diagram showing an example of use of the solid-liquid separation device. The solid-liquid separation device 1 is provided with a filtration unit 2 using a plurality of sheet filtration materials in a solid-liquid separation tank 3 and a washing nozzle 4 provided above the filtration unit 2. is there. As shown in FIG. 2 and FIG. 3, the filtration unit 2 includes a plurality of filtration media 5 in which two planar filter media 5 such as a fine mesh screen and a filter cloth are opposed to each other and the outer periphery thereof is sealed with a frame 6. The module 7 is vertically arranged while being held at a predetermined interval by a spacer 8, and a part of the frame member 6 on the side of the filtration module 7 is provided with a slit-shaped water passage 9
Are formed. Further, the washing nozzle 4 is installed at a position where the washing water can be sprayed toward the filtration surfaces on both sides of the filtration module 7. The water passage 9 is connected to an overflow chamber 11 for keeping the inside of the solid-liquid separation tank 3 at a predetermined water level or higher through an opening 10 provided in a side wall of the solid-liquid separation tank 3. The treated water that has passed through the filter medium 5 is formed so as to overflow the weir 11 a of the overflow chamber 11 and flow down to the treated water tank 12. A raw water inflow path 13 having a raw water inflow valve 13V is provided above the solid / liquid separation tank 3, and a drainage path 14 having a drain valve 14V is provided at the bottom of the solid / liquid separation tank 3.
Is provided. Further, below the drainage path 14,
A drainage tank 15 for receiving washing drainage and the like is provided, and the drainage tank 15 has a drainage lead-out path 1 equipped with a pumping pump 16P.
6 are provided. The treated water tank 12 has a treated water outflow path 1
7 and a cleaning pump 18P and a cleaning valve 18V for supplying a part of the treatment water to the cleaning nozzle 4.
Is provided. Further, the cleaning path 18 includes a chemical solution pump 19P and a chemical solution supply valve 19.
A chemical storage tank 20 is connected via a chemical supply path 19 having V. As shown in the system diagram of FIG. 4, the solid-liquid separation device 1 formed as described above has a final sedimentation basin 21 of a sewage treatment plant.
It can be used as a device that is provided at the subsequent stage and performs tertiary treatment of the secondary treated water treated in the final sedimentation basin 21. That is, the secondary effluent flowing from the overflow weir 22 of the final sedimentation basin 21 flows into the solid-liquid separation tank 3 via the raw water inflow path 13 by natural flow, and remains in the secondary effluent. A tertiary treatment of separating and removing the suspended solids thus separated by the planar filter material of the filtration unit 2 is performed. The tertiary treated water treated by the solid-liquid separator 1 is treated in a treated water tank (tertiary treated water tank) 1
From 2 the water is discharged to a river or the like via the treated water channel 23. Thereby, the advanced treatment in the sewage treatment plant is performed, which can contribute to the reuse of water resources and the like. FIGS. 5 to 9 show a series of processing operations in the solid-liquid separation device 1. FIG. 5 to 9.
Now, only the main part will be described. First, FIG. 5 shows a state of a normal filtration step. The raw water inflow valve 13V is open, the drain valve 14V is closed, and the water pump 16P and the washing pump 18P are stopped. Raw water (secondary treated water) flowing into the solid-liquid separation tank 3 from the raw water inflow path 13 is filtered by the planar filter material of the filtration unit 2, passed through the overflow chamber 11, and treated water tank (tertiary treated water tank) 12. Leaked to At this time, among the suspended solids in the secondary treatment water, those having a small size pass through the filter medium at the beginning of the filtration treatment, but when a sludge cake layer is formed on the filtration surface, Since the sludge cake layer is also filtered, good treated water can be obtained in a short time after the start of the filtration operation. As the filtration process progresses, when the filtration surface is clogged with the suspended matter, the water level in the solid-liquid separation tank 3 gradually rises as shown in FIG. This rise in the water level is detected by a float switch or the like, and when the water level reaches the set water level, the filtration operation is stopped, and the process proceeds to the step of cleaning the filtration surface. In the cleaning step, first, as shown in FIG. 7, the raw water inflow valve 13V is closed, the drain valve 14V is opened, the water in the solid-liquid separation tank 3 is discharged to the drain tank 15, and the filtration of the filtration unit 2 is performed. Perform drainage operation to expose the surface. In addition, pump 1
6P is operated to return the wastewater in the drainage tank 15 to the settling basin or the first settling basin. Next, the cleaning pump 18P is operated to supply the processing water in the processing water tank 12 to the cleaning nozzle 4, and as shown in FIG. 8, the processing water (cleaning water) flows from the cleaning nozzle 4 toward the filtration surface. Squirt. As a result, the suspended matter on the filtration surface is washed away by the washing water, and together with the washed water, the drainage path 1 is removed.
From 4, it flows down to a drain tank 15 and is returned to pretreatment equipment such as a sand basin. At this time, since the washing water ejected from the washing nozzle 4 flows in a direction substantially parallel to the filtering surface, the washing water does not strongly hit the filtering surface, and the filter material may be damaged. Since there is almost no washing, effective washing can be performed using a certain amount of high-pressure washing water. Furthermore, since the filtration surface is exposed to the gas phase, the momentum of the washing water can be directly applied to the filtration surface, and the cleaning efficiency is excellent, and the suspended solids on the filtration surface can be removed in a short time. can do. In addition, since the filtration surface can be washed only by operating a valve or a pump while the filtration unit 2 is installed in the solid-liquid separation tank 3, the filtration can be performed automatically and in a short time. And even if sludge or the like scatters during washing, it does not scatter outside. And as washing water,
Since the treated water stored in the treated water tank 12 is used, clogging of the washing nozzle 4 hardly occurs, and maintenance is easy. When the predetermined washing operation is completed, the washing pump 18P is stopped, the drain valve 14V is closed, and the raw water inflow valve 13V is opened. As a result, the secondary treated water flows into the solid-liquid separation tank 3 from the raw water inflow path 13 and returns to the initial state shown in FIG. Note that the pump 16P may be appropriately stopped according to the situation in the drainage tank 15. As described above, the overflow weir 22 of the final sedimentation basin 21
There is an appropriate water level difference between the water level of
Further, when there is an appropriate space in the water channel, a filtration facility including the solid-liquid separation device 1 can be incorporated in the treatment water channel. In this case, since the secondary treated water flows through the filtration equipment by natural flow, it is not necessary to newly install a pumping equipment. In particular, even in the water channel of the limited space after the final sedimentation basin 21, since a large number of planar filter media are installed in parallel at narrow intervals, the filtration area can be increased, and a large amount of secondary The treated water can be filtered. On the other hand, if microorganisms proliferate on the filtration surface due to a long filtration operation, in the worst case, the filtration material will be blocked. Therefore, it is necessary to perform a treatment for removing microorganisms (biological slime) on the filtration surface by using a chemical solution or the like at an appropriate time. This biological slime can be removed by moving the filtration unit 2 to a chemical washing tank or the like. However, a chemical such as sodium hypochlorite solution or ozone-dissolved water is supplied from the chemical storage tank 20 to the chemical supply path. Washing nozzle 4 through 19
And ejecting it toward the filtration surface. In addition, high-temperature water, high-temperature steam, or the like can be used instead of the chemical solution, and these can be used together. This chemical cleaning can also be performed by spraying from the cleaning nozzle 4 in a state where the filtration surface is exposed to the gas phase, so that the amount of the chemical used can be reduced, and the treatment of the chemical after use becomes easy. . When the chemical cleaning is performed, it is necessary to perform water cleaning before and after the cleaning. However, since the same effect can be obtained by performing the above-described cleaning process, it is not necessary to perform a special water cleaning. In addition, the time and labor required for chemical cleaning can be reduced. The installation position and the number of the washing nozzles 4 can be arbitrarily selected depending on the size of the filtration unit 2 and the like, and can be installed on the side or below. The upper part of the filtration unit 2 is optimal in consideration of scattering of washing water. Also,
Arbitrary water can be used for the cleaning water.
The shape is arbitrary, but a type in which the washing water can be sprayed over the entire filtration surface is preferable, and a type in which the head automatically swings can also be used. Further, the spacers 8 for holding the adjacent filtration modules 7 at a predetermined interval may be provided in an appropriate number of pieces at a suitable position in addition to a rod-like spacer. As described above, according to the solid-liquid separation apparatus of the present invention, the filtration material can be washed very easily and efficiently, so that the interval between the filtration materials can be greatly reduced. Can be. Therefore, a sufficient filtration area can be obtained even with a small installation area, the filtration speed is excellent, and the maintenance can be easily performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram showing an installation example of peripheral devices of a solid-liquid separation device. FIG. 2 is a side view showing one embodiment of a filtration unit. FIG. 3 is a plan view of the same. FIG. 4 is a system diagram showing an example of using a solid-liquid separation device. FIG. 5 is an explanatory diagram showing a state of a filtration step. FIG. 6 is an explanatory diagram showing a state at the end of a filtration step. FIG. 7 is an explanatory diagram showing a state of a drain operation before a cleaning step. FIG. 8 is an explanatory view showing a state of a cleaning step. FIG. 9 is an explanatory diagram showing a state in which a washing step is switched to a filtration step. [Description of Signs] 1 ... solid-liquid separation device, 2 ... filtration unit, 3 ... solid-liquid separation tank, 4 ... washing nozzle, 5 ... planar filter material, 6 ... frame material, 7 ...
Filtration module, 8 ... spacer, 9 ... water inlet, 10 ...
Opening, 11: Overflow chamber, 12: Treated water tank, 13: Raw water inflow path, 14: Drainage path, 15: Drainage tank, 16: Drainage discharge path, 17: Treated water outflow path, 18: Washing path, 19 ...
Chemical solution supply path, 20 ... chemical solution storage tank, 21 ... final sedimentation basin,
22: overflow weir, 23: treated water channel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B01D 29/38 520C 560

Claims (1)

Claims: 1. Solid-liquid separation by holding a plurality of filtration modules with two sheet filters facing each other at a predetermined interval and sealing the outer peripheral portions of the filtration modules at a predetermined interval with a spacer. A liquid nozzle provided in the tank, and having a water inlet communicating with the inside of the filtration module and the outside of the solid-liquid separation tank, and a washing nozzle for jetting washing water toward a filtration surface of the filtration module. Separation device.