JP4901614B2 - Solid-liquid separation processing apparatus and solid-liquid separation processing system - Google Patents

Description

  The present invention relates to a solid-liquid separation processing apparatus and a solid-liquid separation processing system using a flat membrane module.

  As solid-liquid separation treatment apparatuses that have been introduced in recent years, there are a membrane filtration apparatus used in the field of clean water and a membrane separation activated sludge treatment apparatus used in the field of sewage. The apparatus using these membranes replaces the functions of conventional sand filtration tanks and sedimentation basins, and is characterized by easy maintenance and compactness. Clogging of the membrane surface is the biggest problem in solid-liquid separation processing using membranes. Backwashing and air scrubbing at regular intervals in the membrane filtration device for clean water, and the bottom of the tank in the membrane separation activated sludge treatment device for sewage Air scrubbing from has been carried out.

  The main cause of the clogging of the membrane surface is organic substances contained in the raw water. In order to peel this organic material from the film surface by air scrubbing, a large amount of air supply is required. Especially in the sewage membrane separation activated sludge treatment equipment, the water depth is usually in the range of 1m to 4m, and the air supply pressure more than the water head difference is required, so a large amount of electric energy is consumed by the blower, resulting in operation The cost was high.

  In order to solve this problem, [Patent Document 1] In the conventional technique described in Patent Document 1, a membrane element is immersed in a treatment tank, and gas and suspended solids are lifted from below the membrane element, and the lift action and The suspended solid is turbulently flowed by the water flow to remove the solid matter adhering to the film surface.

  As in the prior art described in [Patent Document 1], it is possible to turbulently flow gas and suspended solids to delay the progress of film clogging. However, membrane clogging cannot be made zero, and if it is operated for a certain period, chemical cleaning of the membrane or membrane replacement is required. In such a submerged membrane separation activated sludge treatment apparatus, the submerged membrane is pulled up from the treatment tank and washed. In order to pull up the immersion film, it is necessary to provide a chain block, a crane, and a ceiling support.

  In order to pull up the immersion membrane, the height from the bottom of the treatment tank to the ceiling is required to be at least twice as long as the membrane element length, and there is a restriction on the building structure where the treatment apparatus can be installed. Moreover, when the immersion film was pulled up, the immersion type film was easily damaged, and there was a problem in reliability when the membrane element was installed again. In addition, these pulling operations require time and labor, which has been a factor in raising maintenance costs.

  On the other hand, an apparatus described in [Non-Patent Document 1] has been proposed as a pressure-type membrane separation module instead of an immersion type. The pressure-type membrane separation module is provided with a plurality of flat membrane modules in a casing, and suppresses clogging of the membrane by back pressure washing and raw water cross flow with a flow rate of 1 m / sec. This pressure-type membrane separation module is more advantageous than the immersion-type membrane separation activated sludge treatment device in that it is capable of relatively difficult-to-filter treatment, does not require manual labor for chemical cleaning, and has an installation area. It is said that.

  However, in this apparatus, the gap between the flat membranes is 3 mm, and high pressure is required for flowing raw water through this gap at a flow rate of 1 m / sec. For this reason, there is a problem that a large amount of electric energy is consumed by the pump and the operation cost is increased.

Japanese Patent Laid-Open No. 9-136021 Shinko Pantech Co., Ltd., Shinko Pantech Technical Report Vol.46 No.1, pp.16-17 (2002/8)

  The object of the present invention is to effectively peel off the deposits on the membrane surface to suppress a decrease in the flux of the membrane filtration rate or an increase in the differential pressure of the membrane. An object of the present invention is to provide a small number of solid-liquid separation processing apparatuses and solid-liquid separation processing systems.

  In order to achieve the above object, a solid-liquid separation treatment apparatus of the present invention comprises a casing having an inlet for treated water, an outlet for concentrated water, an outlet for filtered water, and an incoming treated water in the casing. An upward flow generating section that is a counter flow, a flat membrane module that is arranged so that the upward flow flows through a gap between the flat membrane modules, and a specific gravity that is smaller than the distance between the flat membrane modules and is 1.2 to 3.0. And a sedimentation channel for sedimentation of the sedimentation carrier that has risen due to the upward flow.

  In addition, the solid-liquid separation treatment system includes a raw water tank for storing raw water, one of the raw water pipes connected to the liquid phase in the raw water tank and the other connected to the raw water inlet of the solid-liquid separation processing apparatus, and one of which is concentrated. A concentrated water pipe connected to the liquid outlet of the raw water tank at the water outlet, a circulation pump provided in the middle of the raw water pipe or the concentrated water pipe, and a filtration pump connected to the filtered water outlet Equipped with.

According to the present invention, the clogging of the membrane surface can be efficiently reduced, so that the decrease in the flux or the increase in the membrane differential pressure can be suppressed, the operation cost can be reduced, and the membrane chemical cleaning and replacement work is facilitated. A solid-liquid separation processing apparatus can be realized. In addition, in a place where there is no upward water flow, the sedimentary carrier settles to the bottom of the casing and flows along with the water flow again from the raw water inlet at the bottom, so that the sedimentary carrier does not accumulate at the bottom and the membrane The cleaning efficiency of the surface is improved and there is no problem of decay.

  Embodiments of the present invention will be described with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS. 1 is a configuration diagram of a solid-liquid separation processing system of the present embodiment, FIG. 2 is a longitudinal sectional view of a solid-liquid separation processing apparatus that is Embodiment 1 of the present invention, and FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a plan view of the solid-liquid separation processing apparatus according to the first embodiment as viewed from above.

  The raw water tank 52 that stores the raw water 50 and the solid-liquid separation processing apparatus 1 are connected by a raw water pipe 34 (also referred to as a raw water pipe 34), and a circulation pump 38 is provided in the middle of the pipe 34. A concentrated water pipe 46 (also referred to as a concentrated water pipe 46) is connected to the outlet 10 provided in the solid-liquid separation processing apparatus 1, and the pipe 46 is immersed in the liquid phase of the raw water tank 52. A filtration pipe 42 (also referred to as a filtration pipe 42) is connected to the filtrate outlet 14 provided in the solid-liquid separation processing apparatus 1, and a filtration pump 40 is provided in the pipe 42. The circulation pump 38 may be provided in the pipe 46 instead of the pipe 34.

  The raw water 50 stored in the raw water tank 52 is sent to the raw water inlet 20 of the solid-liquid separation processing apparatus 1 by a circulation pump 38 provided in the middle of the pipe 34. The concentrated water is circulated to the liquid phase in the raw water tank 52 via the pipe 46 from the concentrated water outlet 10 of the solid-liquid separation processing apparatus 1. The solid-liquid separation processing apparatus 1 is sealed with a casing 12 described later, and an outlet 10 for concentrated water, an outlet 14 for filtered water, and an outlet 14 for filtered water are provided as openings. The filtered water can be taken from the outlet 14 by the pump 40, and clear filtered water can be obtained by operating the pump 40.

  Since it comprises in this way, it becomes possible to make the state in which the free liquid level does not exist in the casing 12, the piping 34, and the piping 46. FIG. Since the liquid phase is continuous through the raw water 50 in the raw water tank 52, the pipe 34 and the pipe 46 act as siphons. Therefore, the water head difference is negligibly small as the discharge pressure of the circulation pump 38, and the discharge pressure is determined by the pipe resistance and the flow resistance in the solid-liquid separation processing apparatus 1. Since the solid-liquid separation processing system of the present embodiment is configured as described above, the power of the circulation pump 38 can be reduced, so that cost-saving operation can be realized.

  The solid-liquid separation processing apparatus 1 is formed in a rectangular parallelepiped shape with a casing 12, a raw water inlet 20 is provided on a lower side surface of the casing 12, and a rectifying unit 22 is provided at a position facing the inlet 20 in the casing 12. Is provided. The rectifying unit 22 is formed of a flat plate having one end fixed to the bottom surface of the casing 12 and the other end fixed to the side surface on the back side of the casing 12 and inclined. As shown in FIG. 3, the rectifying unit 22 is provided with a width between the casings 12 so that at least the sedimentary carrier 18 does not enter the space between the rectifying unit 22 and the casing 12. A plurality of flat membrane modules 24 are installed above the rectifying unit 22 in the casing 12, and each flat membrane module 24 is fixed by a flat membrane fixing portion 26 provided on the left and right casings 12 as viewed from the inlet 20. ing. The rectification unit is also referred to as an upward flow generation unit.

  Tubular filtered water outlet 14 is installed on the upper part of flat membrane module 24, and the inside of the filtration membrane of each flat membrane module 24 is connected to communicate with outlet 14. The outlet 14 is attached through the casing 12 and is fixed to the casing 12 by welding or the like. A concentrated water outlet 10 is provided on the upper surface of the casing 12. On the side of the flat membrane module 24 in the casing 12, a settling channel 28 is formed, which is a space for moving the settling carrier 18 flowing in the casing 12 downward. The sedimentary carrier 18 is enclosed in the casing 12 and formed to be smaller than the distance between the flat membrane modules 24 so as to freely flow between the flat membrane modules 24.

  As shown in FIGS. 6 and 7, the concentrated water outlet 10 is provided with a carrier separating mesh 32 having a diameter smaller than that of the sedimentary carrier 18. Since the sedimentary carrier 18 flowing in the casing 12 rises in the gap of the flat membrane module 24 and the flow velocity of the upward flow once decreases, most of the sedimentary carrier 18 flows into the sedimentation flow path 28 and settles.

  However, depending on the specific gravity, size, surface properties of the carrier, and the upper structure of the casing 12, the concentrated water may reach the vicinity of the outlet 10 and flow out of the casing 12. As shown in FIG. 6, the sedimentation carrier 18 can be reliably separated by providing the carrier separation mesh 32 having a smaller diameter than the sedimentation carrier 18 at the outlet 10 of the concentrated water. As a result, it is possible to eliminate the possibility that the sedimentation carrier 18 flows out into the concentrated water and induces clogging or failure of the pipes or pumps, or the possibility that the number of the sedimentation carriers 18 is reduced and the cleaning effect is reduced. . In addition, when solid-liquid separation of raw water containing fibrous substances such as sewage treated water, the fibrous substance may be entangled with the mesh 32 and a pressure loss may occur, so the mesh 32 or the mesh 32 is fixed. It is desirable that the member has a shape that can be removed and easily replaced. Further, it is desirable to provide a pressure gauge, a manometer or the like in the casing 12 so that the internal pressure is clearly indicated so that the amount of clogging can be easily understood from the outside.

  The raw water to be treated flows into the casing 12 from the inlet 20. Since the inertia force acts on the inflowing raw water, the raw water reaches the left side of the casing 12 and becomes an upward flow due to the inclination of the rectifying unit 22. Inside the casing 12, the flat membrane module 24 is fixed at regular intervals by a flat membrane fixing portion 26.

  The raw water moves upward through the gap of the flat membrane module 24. At that time, the sedimentary carrier 18 floating in the casing 12 or sinking to the bottom is caused to flow. The raw water that has moved upward flows out from the outlet 10 of the concentrated water.

  When the raw water exceeds the upper end portion of the flat membrane module 24, the flow path area increases, and the upward flow velocity decreases. As will be described later, the sedimentary carrier 18 has a specific gravity larger than that of water, so that the speed of moving upward decreases, stays, and moves in the horizontal direction. A settling channel 28 is provided in the casing 12 so as not to be affected by the upward flow caused by the inflowing raw water. The sedimentary carrier 18 passes through the sedimentation channel 28 and moves downward by gravity.

  The sedimentary carrier 18 that has moved downward is made to flow again by the raw water flowing in from the raw water inlet 20 provided below, and moves upward through the gap in the flat membrane module 24.

  On the other hand, a filtration pump 40 is connected to the filtrate outlet 14, and the inside of the flat membrane module 24 is suction filtered to obtain filtrate, and the filtrate is taken out from the outlet 14.

  As one of the membrane cleaning mechanisms of the flat membrane module 24 by bubbles, the rising bubbles generate a cross-flow water flow in parallel with the membrane surface of the flat membrane module 24, making it difficult for microorganisms of activated sludge and their in vitro substances to adhere. There is a phenomenon.

  In this embodiment, the sedimentary carrier 18 is caused to flow with the amount of crossflow water generated by the kinetic energy of raw water flowing in from the raw water inlet 20, and the impact energy when the sedimentary carrier 18 collides with the deposit on the membrane surface. Remove deposits.

In general, the kinetic energy E of the solid flowing by the water flow is expressed by Equations 1 and 2.
[Equation 1]
E = (1/2) m · v ² (1)
[Equation 2]
m = ρ · V (2)
Here, m is the mass of the solid, v is the moving speed of the solid, ρ is the specific gravity of the solid, and V is the volume of the solid. From Equations 1 and 2, it can be seen that the kinetic energy E of the solid increases as the specific gravity ρ of the solid increases. That is, the larger the specific gravity ρ of the sedimentary carrier 18, the higher the peeling effect when the sedimentary carrier 18 flows and collides with or comes into contact with the film surface deposit. When the specific gravity ρ is large, the sedimentation property is increased. Therefore, the sedimentation carrier 18 is sedimented toward the bottom of the casing 12 at a place where no upward water flow exists. Since the raw water inlet 20 is provided at the bottom, the settled carrier 18 that has settled again flows along with the water flow and flows through the gaps in the flat membrane module 24 to separate the deposits on the membrane surface.

  FIG. 5 shows the relationship between the specific gravity of the sedimentary carrier 18 and the deposit peeling effect. When the specific gravity of the sedimentation carrier 18 is increased, the effect of peeling off the deposit is increased up to the sedimentation carrier 18 having a specific gravity. However, in the sedimentary carrier 18 having a specific gravity or higher, the specific gravity is too large and too heavy to decrease the fluidity, and the ratio of the sedimentary carrier 18 flowing along with the upward flow generated by the rectifying unit 22 decreases. As a whole, the deposit peeling effect is reduced. As a result of examination, the specific gravity of the sedimentary carrier 18 is appropriately in the range of 1.2 to 3.0.

  Thus, the cleaning effect of the membrane surface can be increased by using the sedimentary carrier 18 that flows by the kinetic energy of the incoming raw water. As a result, air scrubbing, which was necessary in the conventional immersion type apparatus, becomes unnecessary, and the flow rate required for 1 m / sec in the conventional pressure-type membrane module can be reduced, so that cost-saving operation is possible.

In general, the pipe resistance R is proportional to the square of the flow velocity V as shown in Equation 3.
[Equation 3]
R = k · V ² (3)
From this relationship, the flow rate required in the conventional pressure membrane module can be halved, so that the filtration resistance of the pressure membrane module can be reduced to ¼. Excluding the water head difference, the energy consumption of the circulation pump can be reduced to 1/4.

  In addition, although the present Example demonstrated the case where the inlet 20 of raw | natural water was one place as shown in FIG. 2, the same flow velocity is obtained in all the membrane surfaces as much as possible by providing the inlet 20 in multiple places. It is desirable to make it.

  Although not shown in FIG. 2, a partition is provided between the side where the flat membrane module 24 is installed and the settling channel 28 so that upward flow is surely generated in the gap between the flat membrane modules 24. It is desirable.

  A large amount of solid-liquid separation processing can be performed by operating a plurality of solid-liquid separation processing apparatuses of this embodiment in parallel. At that time, it is desirable that the raw water inlet 20, the concentrated water outlet 10, and the filtered water outlet 14 should be attached so that the external water collection pipe can be easily detached. Specifically, it is desirable to use a plug-in type or screw-in type inlet or outlet, but a flange connection that is normally used may be used. Although not shown in FIG. 2, it is desirable to provide a drain for draining at the bottom of the casing 12. In addition, it is practically desirable to provide a hole or mouth for taking out the sedimentary carrier 18.

  A second embodiment of the present invention will be described with reference to FIGS. 8 is a longitudinal sectional view of the solid-liquid separation processing apparatus of the present embodiment, and FIG. 9 is a sectional view taken along the line BB in FIG.

  The present embodiment is configured in the same manner as in the first embodiment, but in this embodiment, as shown in FIG. 9, the sedimentary carrier 18 that has settled is inclined toward the raw water inlet 20 at the bottom of the casing 12. The inclination part 30 which has is provided.

  The sedimentation carrier 18 passes through the sedimentation channel 28 and descends onto the inclined portion 30. Without the inclined portion 30, if the sedimentary carrier 18 accumulates in the corner portion in the casing 12, it cannot be used for cleaning the membrane surface. As a result, the membrane surface cleaning effect is reduced, and adverse effects such as the propagation of microorganisms at the location where the sedimentary carrier 18 has accumulated and decay.

  In this embodiment, since the inclined portion 30 is provided, the sedimentary carrier 18 that has settled moves in a vertical direction and a horizontal direction toward a lower portion by gravity. Since the raw water inflow port 20 is provided at the destination, the sedimentary carrier 18 circulates in the casing 12 without accumulating at the bottom, and the cleaning efficiency of the membrane surface is improved. Further, since the sedimentary carrier 18 does not accumulate, problems such as decay do not occur.

  Thus, by providing the inclined portion 30 having a gradient toward the raw water inflow port 20 at the lower portion of the casing 12, the cleaning efficiency of the membrane surface can be further increased, and as a result, the circulation flow rate, that is, the flow velocity of the raw water is reduced. This enables further cost-saving operation.

  A third embodiment of the present invention will be described with reference to FIGS. 10 is a longitudinal sectional view of the solid-liquid separation processing apparatus of the present embodiment, and FIG. 11 is a sectional view taken along the line CC in FIG.

  The present embodiment is configured in the same manner as in the first embodiment, but in this embodiment, as shown in FIG. 10, an upward raw water inlet 20 is provided at the bottom of the casing 12, and instead of the rectifying section 22. In addition, the sedimentation carrier 18 that has settled is provided with an inclined portion 30 having a gradient toward the inlet 20 of the raw water. The upward raw water inlet 20 is also referred to as an upward flow generator.

  By doing in this way, it becomes possible to generate an upward flow efficiently in the casing 12. Further, the settled sedimentary carrier 18 moves along the inclined portion 30 toward the raw water inflow port 20 and efficiently rises and flows from the inflow port 20 having a large flow velocity along with the upward flow. Therefore, the cleaning effect on the film surface is further enhanced. 10 and 11 show the case where the raw water inlet 20 is provided at one place, but a plurality of raw water inlets 20 are provided so that a uniform upward flow velocity can be obtained on all membrane surfaces as much as possible. It is desirable.

  When the raw water inlet 20 is provided at the bottom of the casing 12 as described above, the casing 12 cannot be installed in a floor-standing state. In that case, it is necessary to provide legs under the casing 12. .

The block diagram of the solid-liquid separation processing system which is Example 1 of this invention. The longitudinal cross-sectional view of the solid-liquid separation processing apparatus of a present Example. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The top view which looked at the solid-liquid separation processing apparatus of a present Example from the top. The figure which shows the relationship between the specific gravity of a sedimentation support | carrier, and the deposit | attachment peeling effect. Sectional drawing which shows the mesh provided in an outflow port. The perspective view of the mesh provided in an outflow port. The longitudinal cross-sectional view of the solid-liquid separation processing apparatus of Example 2 of this invention. FIG. 9 is a cross-sectional view taken along the line BB in FIG. 8. The longitudinal cross-sectional view of the solid-liquid separation processing apparatus of Example 3 of this invention. FIG. 11 is a cross-sectional view taken along the line CC in FIG. 10.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-liquid separation processing apparatus 10 and 14 Outlet 12 Casing 16 Water collecting pipe 18 Sediment carrier 20 Inlet 22 Rectification part 24 Flat membrane module 26 Flat membrane fixing part 28 Sedimentation flow path 30 Inclination part 32 Mesh 34, 42, 46 Piping 38, 40 Pump 50 Raw water 52 Raw water tank

Claims (8)

A casing having an inlet for water to be treated, an outlet for concentrated water, and an outlet for filtrate water, and an upper portion of the water to be treated disposed in a position opposite to the inlet provided in the lower part of the casing. An upward flow generating section as a counter flow, a flat membrane module disposed above the upward flow generating section so that the upward flow flows through a gap between the flat membrane modules, and a flat membrane module enclosed in the casing smaller than the distance between the flat sheet membrane module for precipitating the precipitated carrier is in the range of specific gravity 1.2 to 3.0, the precipitated carrier elevated between the flat sheet membrane module by the upward flow And a sedimentation flow path formed on the side of the inlet on the side of the solid-liquid separation processing apparatus. A plurality of flat membrane modules installed in a casing forming a hermetic container, an outlet for filtered water attached to the casing and for taking out filtrate water of the flat membrane module, and provided at a lower portion of the casing An upward flow generating section disposed at a position facing the inlet for generating an upward flow for raising the treated water and the sedimentary carrier flowing in from the inlet into the flat membrane module; and the flat membrane A solid-liquid separation processing apparatus comprising: a settling channel formed on the inflow side on the side of the flat membrane module for settling the settling carrier rising between the modules.   The solid-liquid separation processing apparatus of Claim 1 or 2 which installed the inclination part in which the settled sedimentation support | carrier settled toward the inflow port of raw | natural water was installed in the lower part of the said sedimentation flow path.   The solid-liquid separation processing apparatus according to claim 1, wherein the upward flow generation unit is formed as an inclined flat plate facing the inflow port.   The solid-liquid separation processing apparatus according to claim 1, wherein a carrier separation mesh having a pore diameter smaller than that of the sedimentary carrier is provided at the outlet of the concentrated water.   The solid-liquid separation processing apparatus according to claim 1, wherein the casing is hermetically sealed except for the raw water inlet, the concentrated water outlet, and the filtered water outlet. A raw water tank for storing raw water to be treated, one of the raw water pipes connected to the liquid phase in the raw water tank, the other connected to the raw water inlet of the solid-liquid separation processing apparatus, and one of the solid-liquid separation treatment Filtration comprising a concentrated water pipe connected to the concentrated water outlet of the apparatus, the other connected to the liquid phase of the raw water tank, and a filtered water pump connected to the filtered water outlet of the solid-liquid separation treatment apparatus A circulation pump provided in any of the raw water pipe and the concentrated water pipe, and the solid-liquid separation treatment apparatus supplies raw water and a sedimentary carrier flowing in from the inlet located in the lower part , In order to settling the upward flow generating unit disposed at a position facing the inflow port that generates an upward flow that raises a plurality of installed flat membrane modules, and the rising carrier that has risen between the flat membrane modules the flow in the side of the flat membrane module Solid-liquid separation treatment system having a sedimentation flow path formed in the mouth side.   The solid-liquid separation according to claim 7, wherein a plurality of the solid-liquid separation treatment devices are installed, and the inflow port of the treated water, the outflow port of filtered water, and the outflow port of concentrated water are connected to the pipes by attachments. Processing system.

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