JP2011041923A - Solid-liquid separator and solid-liquid separation method by precoat rotary drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform solid-liquid separation by forming a precoat layer PC on a solid-liquid separation drum 2 without using an auxiliary agent or a precoating agent, for the purpose of effectively utilizing recovered suspended solids. <P>SOLUTION: The solid-liquid separator includes: a treatment tank 1 to which water to be treated is supplied; a solid-liquid separation drum 2 which is rotatably arranged around the horizontal axial center, with a part immersed in the water W1 to be treated in this treatment tank 1 and which has an outer peripheral wall composed of a mesh material 21; a recovery means 3 which separates and collects the precoat layer PC comprising suspended solids stuck and accumulated on the outer peripheral face of the mesh material 21; and a draining means 12 for draining filtered water W2 passed into the solid-liquid separation drum 2. The meshes of the mesh material 21 are 150 μm or less, so that the precoat layer PC can be formed without applying a precoating agent preliminarily onto the mesh material 21 in the initial solid-liquid separation process. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solid-liquid separation apparatus and solid-liquid separation for separating and recovering the suspended solids using a drum-like filter that forms a precoat layer of suspended solids (suspension) in the solid-liquid separation target water on the outer peripheral surface. A method is provided.

  In recent years, the importance of resource recycling and effective use through waste reduction and reuse has increased. Organic matter contained in low-concentration organic wastewater discharged in large quantities from food factories and crushed garbage generated from disposers and wastewater treatment systems that have been rapidly spreading in urban areas in recent years are effectively used. It is processed as it is. This is because these organic substances have a problem that the concentration is too low to be used as a biomass resource as it is, and the load is high to perform wastewater treatment.

  Here, as a solid-liquid separation device that separates and collects suspended solids from wastewater, a device using a pre-coated rotary drum as disclosed in the following patent document is known. In the paper industry, pulp concentration is known. It is used for white water treatment.

  A conventional solid-liquid separation device using a pre-coated rotary drum is disposed in a treatment tank for storing water to be treated and a rotation centered around a horizontal axis (not shown) in the treatment tank. A solid-liquid separation drum made of a mesh material such as cloth, and a scraper or cutter that peels and collects a pre-coat layer made of a floating solid adhered to and deposited on the outer peripheral surface of the mesh material.

  That is, this type of solid-liquid separation device supplies water to be treated into the treatment tank and drains water (filtered water) filtered into the solid-liquid separation drum from the internal space of the rotating solid-liquid separation drum. As a result, a precoat layer is formed on the outer peripheral surface of the mesh material of the solid-liquid separation drum, where suspended solids adhere to and accumulate on the water to be treated, and the mesh material is opened using the filtration function of the precoat layer itself. It is possible to separate and collect suspended solids with finer particles than the size. The amount of wastewater treated, the thickness of the precoat layer, and the quality of the filtrate can be adjusted by the rotation speed of the solid-liquid separation drum.

  In this type of solid-liquid separation device using a precoat type rotating drum, if the concentration of suspended solids in the water to be treated is low, the formation of the precoat layer becomes non-uniform, so the concentration is required to be 0.5% or more. .

Japanese Patent Laid-Open No. 7-213819 JP 2000-254418 A

  However, this type of solid-liquid separation device using a pre-coated rotary drum, when used for concentrating pulp, is a solid solid with a fibrous form, low sedimentation, and a high concentration of 0.5% or more. A pre-coat layer is easily formed on the surface of the mesh material of the liquid separation drum, and the mesh material can efficiently collect suspended solids even with an opening of about 300 μm. However, suspended solids in food factory wastewater and domestic wastewater contain particles. Since it is fine and non-uniform in shape and exists at a low concentration, it is difficult to efficiently recover these with a mesh material having an opening of about 300 μm.

  Therefore, in order to treat wastewater with finer particles of suspended solids, such as papermaking white water and cement wastewater, using a coarse solid-liquid separation drum with a mesh size used in papermaking, an auxiliary agent such as a coagulating precipitant is added. A method for promoting the formation of a precoat layer by adding a precoat agent to the mesh material in advance, and the precoat layer made of suspended solids formed on the mesh material in the solid-liquid separation step is peeled off and collected together with the precoat agent. The technique is taken. However, in this case, there is a concern about an increase in cost due to the use of a coagulating precipitant or a precoat agent, and an auxiliary agent or a precoat agent is mixed into the recovered material, which is inconvenient for effective use of the recovered material. is there.

  In addition, when selecting a solid-liquid separator using a pre-coated rotary drum, it is necessary to confirm the properties of the wastewater. However, since the mesh size of the mesh material is selected from the existing sizes, it is appropriate for various types of wastewater. The size may not be selected. In addition, when the amount of waste water is small, the amount of suspended solids in the water to be added is also small, so depending on the mesh size and drum size, it becomes difficult to form a precoat layer uniformly, and the filtration accuracy becomes unstable. There's a problem.

  The present invention has been made in view of the above points, and the technical problem is that the collected suspended solids are effectively used, so that the suspended solids can be used without using an auxiliary agent or a precoat agent. The object is to efficiently perform solid-liquid separation by forming a precoat layer on a solid-liquid separation drum.

  As a means for effectively solving the technical problem described above, a solid-liquid separation device using a precoat type rotary drum according to the invention of claim 1 includes a treatment tank to which water to be treated is supplied, and the treatment tank in which the water is treated. A solid-liquid separation drum that is arranged so as to be rotatable around a horizontal axis while partially immersed in water to be treated, and whose outer peripheral wall is made of a mesh material, and floating solid matter that adheres and accumulates on the outer peripheral surface of the mesh material. And a drainage means for discharging the filtrate that has passed through the solid-liquid separation drum, and the mesh material of the solid-liquid separation drum has a mesh opening of 150 μm or less. It is what.

  According to the solid-liquid separation device using the precoat type rotary drum having the above-described configuration, the water to be treated in the treatment tank is separated from the filtrate in the internal space of the solid-liquid separation drum by the head difference, so that the outer peripheral wall of the solid-liquid separation drum Is filtered through a precoat layer formed by adhering and depositing suspended solids on the outer peripheral surface of the mesh material, and becomes clear filtrate and flows into the interior space of the solid-liquid separation drum. The precoat layer is sequentially peeled and collected by the collecting means.

  And according to the research of the inventors of the present invention, when the mesh size of the mesh material of the solid-liquid separation drum is larger than 150 μm, if the pre-coating agent is not previously applied to the mesh material in the initial solid-liquid separation step, the mesh material Adhesion and accumulation of suspended solids are unlikely to occur on the outer peripheral surface of the material, that is, a precoat layer is not formed, but if the mesh size is 150 μm or less, the pre-coating agent is not applied to the mesh material in advance in the initial solid-liquid separation process However, it was found that a precoat layer was formed. Therefore, according to the present invention, the mesh material of the solid-liquid separation drum has an opening of 150 μm or less.

  Further, the solid-liquid separation device using the precoat type rotating drum according to the invention of claim 2 is the structure of claim 1, wherein the concentration of suspended solids in the water to be treated in the treatment tank is such that the outer periphery of the solid-liquid separation drum is The side where the precoat layer is peeled off by the recovery means along with the rotation and then the side that immerses below the water surface is relatively low in concentration, and the side where the outer periphery of the solid-liquid separation drum floats above the water surface along with the rotation is relatively The water to be treated supplied to the treatment tank is guided to a position where the outer periphery of the solid-liquid separation drum is unevenly distributed on the surface of the water surface so as to be high concentration.

  According to a third aspect of the present invention, there is provided the solid-liquid separation device using the pre-coated rotary drum, wherein the solid-liquid separation drum is open on one side in the axial direction, and the open side is provided. The outer diameter portion of the processing tank is slidably in close contact with the inner side surface of one side wall of the processing tank, and a filtrate reflux tank communicating with the inner space of the solid-liquid separation drum is provided outside the one side wall. It is characterized in that the filtrate can be refluxed from the filtrate reflux tank to the treatment tank via a pump.

  Moreover, the solid-liquid separation method which concerns on invention of Claim 4 supplies process target water to the processing tank of the solid-liquid separation apparatus by the precoat-type rotary drum in any one of Claims 1-3, This process target water In the process of passing to the inside of the solid-liquid separation drum, a pre-coating layer is formed on the outer peripheral surface of the solid-liquid separation drum by depositing and depositing floating solids contained in the water to be treated, The water to be treated is filtered by the precoat layer toward the internal space of the solid-liquid separation drum due to a water head difference between water and filtered water flowing into the internal space of the solid-liquid separation drum. Is.

  Further, in the solid-liquid separation method according to the invention of claim 5, in the method of claim 4, the water to be treated supplied to the treatment tank is a supernatant water from which a substance having good sedimentation properties has been removed as a pretreatment. It is characterized by this.

  Further, the solid-liquid separation method according to the invention of claim 6 is the method according to claim 4, wherein the water to be treated supplied to the treatment tank is a suspension water obtained by pulverizing suspended solids in water into a slurry. It is characterized by being.

  A solid-liquid separation method according to a seventh aspect of the present invention is the method according to any one of the fourth to sixth aspects, wherein the filtrate that has flowed into the internal space of the solid-liquid separation drum at the initial stage of the solid-liquid separation step. A precoat layer is formed on the outer peripheral surface of the mesh material of the solid-liquid separation drum by circulating it back to the treatment tank, and the head of the filtered water in the internal space of the solid-liquid separation drum and the water to be treated in the treatment tank When the difference reaches a predetermined value, the filtered water is drained.

  According to the solid-liquid separation device using the pre-coated rotary drum according to the first aspect of the present invention, the solid-liquid separation drum does not need to be negatively pressured because it is filtered by a head difference, and the solid-liquid separation drum Since the mesh material has an opening of 150 μm or less, it is not necessary to apply a precoat agent to the mesh material in advance in the initial filtration step, so that the cost can be reduced.

  According to the solid-liquid separation device using the precoat type rotating drum according to the second aspect of the invention, the water to be treated supplied to the treatment tank is guided to a position where the outer periphery of the solid-liquid separation drum is unevenly distributed on the side where it floats on the water surface. Thus, in addition to the effect of claim 1, the concentration of suspended solids in the water to be treated is relatively relative to the side where the outer periphery of the solid-liquid separation drum is submerged below the water surface after the precoat layer is peeled off by the collecting means as it rotates. Since the concentration of the outer periphery of the solid-liquid separation drum rises to the surface of the water as it rotates, the concentration of the particles contained in the water to be treated supplied to the treatment tank is relatively high. Large suspended solids adhere to the precoat layer that has grown to a certain thickness, and on the side where the outer periphery of the solid-liquid separation drum is immersed in the water surface after the precoat layer is peeled and recovered by the recovery means, Since solid particles with a relatively large particle size are unlikely to adhere to the mesh material with no coating layer formed, a uniform precoat layer can be formed, and the concentration of suspended solids in the water to be treated is low at this position. Therefore, the water quality of the filtrate can be maintained.

  According to the solid-liquid separation device using the pre-coated rotary drum according to the invention of claim 3, in addition to the effect of claim 1 or 2, filtered water that has flowed into the internal space of the solid-liquid separation drum in the initial stage of the solid-liquid separation step Is recycled to the treatment tank to prevent the drainage from being discharged to the subsequent stage until the precoat layer having the required layer thickness is formed on the outer peripheral surface of the mesh material of the solid-liquid separation drum. An increase in the load on can be prevented.

  According to the solid-liquid separation method according to the invention of claim 4, the separation and recovery of the floating solid from the water to be treated can be efficiently performed at low cost.

  According to the solid-liquid separation method according to the invention of claim 5, in addition to the effect of claim 4, since the substance having good sedimentation is previously removed from the water to be treated, the water to be treated in the treatment tank is mixed with a stirrer or the like. Therefore, a uniform precoat layer can be formed on the outer peripheral surface of the mesh material of the solid-liquid separation drum.

  According to the solid-liquid separation method according to the invention of claim 6, in addition to the effect of claim 4, the water to be treated is suspended water obtained by previously pulverizing suspended solids in water to form a slurry. It is not necessary to stir the water to be treated with a stirrer or the like, and a uniform precoat layer can be formed on the outer peripheral surface of the mesh material of the solid-liquid separation drum.

  According to the solid-liquid separation method of the seventh aspect of the invention, the filtrate is discharged after the filtration function by the precoat layer is expressed, so that the floating solid having a particle size corresponding to the mesh size of the mesh material. It is possible to prevent an increase in load in the subsequent processing step due to filtered water containing substances.

It is sectional drawing which shows schematically the 1st form of the solid-liquid separator by the precoat-type rotary drum which concerns on this invention. It is sectional drawing which shows schematically the 2nd form of the solid-liquid separator by the precoat-type rotary drum which concerns on this invention. It is III-III sectional drawing in FIG. It is sectional drawing which shows schematically the 3rd form of the solid-liquid separator by the precoat-type rotary drum which concerns on this invention. It is VV sectional drawing in FIG. It is sectional drawing which shows schematically the 4th form of the solid-liquid separator by the precoat-type rotary drum which concerns on this invention.

  Hereinafter, preferred embodiments of a solid-liquid separation apparatus and a solid-liquid separation method using a precoat type rotating drum according to the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows a first embodiment of a solid-liquid separation device using a precoat type rotating drum according to the present invention, and FIG. 2 shows a second embodiment, both of which are treatments for storing the water to be treated W1. The tank 1, the solid-liquid separation drum 2 disposed in the treatment tank 1, and the precoat layer PC formed by floating solids in the water to be treated W 1 on the outer peripheral surface of the solid-liquid separation drum 2 are separated and collected. And a recovery means 3.

  In the treatment tank 1, a drain port 12 is opened at a lower portion of a surface facing the solid-liquid separation drum 2 in one side wall 11 shown in FIG. 3.

  The solid-liquid separation drum 2 is rotated at a low speed around a horizontal virtual axis while being immersed in the treatment target water W1 in the treatment tank 1, and as shown in FIG. One side is open. The cylindrical outer peripheral wall is made of a mesh material 21 such as a wire cloth, and the outer diameter portion on the opened side slides on the inner side surface of one side wall (side wall in which the drain port 12 is opened) 11 of the treatment tank 1. A drainage storage chamber S is defined between the sidewall 11 and the side wall 11 by being brought into close contact with each other. Reference numeral 22 is a seal member provided around the opened outer diameter portion of the solid-liquid separation drum 2.

  The solid-liquid separation drum 2 having a diameter of 50 cm or more is adopted, and the mesh material 21 of the solid-liquid separation drum 2 forms a precoat layer PC without applying a precoat agent to the outer peripheral surface of the mesh material 21. Capable of 150 μm or less. Mesh materials include stainless steel, zinc, brass, aluminum and other metals, polyethylene, polypropylene, polyester, polyvinyl chloride, nylon, polytetrafluoroethylene and other synthetic resins, shoji paper and other pulp fibers, glass fibers, carbon It is possible to use fibers.

  In FIG. 1 or FIG. 2, when the solid-liquid separation drum 2 is rotated clockwise, the outer peripheral portion (precoat layer PC) of the solid-liquid separation drum 2 is the side indicated by reference numeral 1a (hereinafter referred to as drum). It floats from the surface of the water to be treated W1 at the floating side 1a) and immerses below the surface of the water to be treated W1 at the side indicated by reference numeral 1b (hereinafter referred to as the drum immersion side 1b). A water supply pipe 13 is opened at the upper part of the treatment tank 1 on the drum immersion side 1b. In the treatment tank 1, water to be treated W1 supplied into the treatment tank 1 by the water supply pipe 13 is provided. From the position where the outer periphery of the solid-liquid separation drum 2 is immersed below the water surface as it rotates, preferably from the bottom of the solid-liquid separation drum 2 (intersection with the vertical line passing through the axis). In addition, a flow guide member 14 is provided so as to be in contact with the outer periphery of the solid-liquid separation drum for the first time in the forward direction of rotation and to be supplied in the rotation direction (clockwise). In other words, the flow guide member 14 guides the water to be treated W1 supplied to the treatment tank 1 to a position unevenly distributed on the drum floating side 1a.

  In the first embodiment shown in FIG. 1, the recovery means 3 for peeling the precoat layer PC and recovering it as a solid C is the surface of the precoat layer PC formed on the outer peripheral surface of the mesh material 21 of the solid-liquid separation drum 2. The precoat layer PC from the mesh material 21 of the solid-liquid separation drum 2 is rotated in the opposite direction to the solid-liquid separation drum 2 while being in contact with the treatment target water W1 above the water level L1 in the treatment tank 1. And a scraper 32 that scrapes off the solid C transferred and adhered to the roller 31. As the surface material of the roller 31, for example, a material that emphasizes smoothness, elasticity, and durability, such as rubber, felt, sponge, or the like is used.

  In the second embodiment shown in FIG. 2, the collecting means 3 for peeling and collecting the precoat layer PC includes a scraper 33 that scrapes off the precoat layer PC formed on the outer peripheral surface of the mesh material 21 of the solid-liquid separation drum 2. Become.

  Next, using the solid-liquid separator configured as described above, for example, organic wastewater (life wastewater, food factory wastewater, methane fermentation digestive fluid, organic sludge, etc.) and inorganic wastewater (inorganic sludge, cement wastewater) A method for separating and recovering suspended solids from polishing / cutting wastewater, silicon processing wastewater, etc.) will be described.

  Here, kitchen wastewater discharged from general households and organic wastewater discharged from food factories contain disposer crushed materials and food waste, and inorganic wastewater discharged from product processing factories is cut and polished. This includes particles such as iron and copper produced by processing such as silicon and particles such as silicon. Therefore, these wastewaters are supplied as supernatant water that has been removed by precipitating substances with good sedimentation in a sedimentation tank (not shown) as a pretreatment, or suspended solids in water are pulverized in advance using a mixer or the like. And supplied as slurry water.

  As shown in FIG. 1 or FIG. 2, the above-described waste water (processing target water W <b> 1) is supplied into the processing tank 1 through the water supply pipe 13. The treatment target water W1 supplied to the treatment tank 1 is separated from the solid-liquid separation drum 2 by the head difference HD with the filtrate W2 in the filtrate storage chamber S of the solid-liquid separation drum 2 immersed in the treatment target water W1. Is filtered by the mesh material 21 of the outer peripheral wall and the precoat layer PC formed by adhering and depositing floating solids on the outer peripheral surface thereof, and filtered to the filtrate storage chamber S between the solid-liquid separation drum 2 and the side wall 11. It flows in as water W2 and is discharged from a drain port 12 established in the treatment tank 1.

  When the solid-liquid separation drum 2 rotates in the clockwise direction in FIG. 1 or FIG. 2, the mesh material 21 of the solid-liquid separation drum 2 is precoated layer PC by the recovery means 3 above the surface of the water to be treated W1. Is removed, the drum immersion side 1b is immersed below the surface of the water to be treated W1, and from this position, the formation of the precoat layer PC is started by adhesion and deposition of floating solids contained in the water to be treated W1. The thickness of the precoat layer PC increases as it moves clockwise in the treatment target water W1, and floats from the water surface at the drum floating side 1a, and the precoat layer PC is recovered by the recovery means. The operation of peeling and collecting by 3 is repeated every rotation.

  However, since no precoat layer PC is formed on the outer peripheral surface of the mesh material 21 of the solid-liquid separation drum 2 at the initial stage of the solid-liquid separation step, all floating solids having a particle size equal to or smaller than the mesh size are not filtered. In other words, it passes to the filtrate storage chamber S between the solid-liquid separation drum 2 and the side wall 11. Therefore, in the initial stage of the solid-liquid separation step, first, the water to be treated W1 is supplied to the treatment tank 1 until the solid-liquid separation drum 2 is submerged in half or more, and the solid-liquid separation drum 2 is stopped while rotating. The drainage water W2 in the filtrate storage chamber S of the separation drum 2 is not discharged but is collected from the drain port 12 by a pump (not shown), and is supplied to the treatment tank 1 and circulated again. By doing so, it is possible to prevent an increase in load in the subsequent processing step due to the filtrate W2 containing floating solids having a particle size corresponding to the mesh size of the mesh material 21.

  Here, since the mesh material 21 of the solid-liquid separation drum 2 has a mesh size of 150 μm or less, the surface of the mesh material 21 can be attached with the floating solid matter without applying a precoat agent. A precoat layer PC by deposition is formed over time. When the precoat layer PC is formed, the precoat layer PC itself has a filtering function, so that the particle size is smaller than the mesh size of the mesh material 21 as the deposition thickness of the precoat layer PC increases. The suspended solids are also effectively separated. Therefore, while the rotation of the solid-liquid separation drum 2 is stopped, the filtrate W2 is refluxed from the filtrate storage chamber S to the treatment tank 1 and circulated, so that the treatment liquid 1 into the solid-liquid separation drum 2 is circulated. As the water flow rate gradually decreases, the concentration of suspended solids in the filtrate W2 decreases, the water level L1 in the treatment tank 1 rises, and the filtrate W2 in the solid-liquid separation drum 2 and the treatment tank 1 The water head difference HD with the water to be treated W1 increases.

For this reason, the precoat layer PC formed on the outer peripheral surface of the mesh material 21 of the solid-liquid separation drum 2
When the water layer difference HD reaches a predetermined value, the circulation of the filtrate W2 to the treatment tank 1 is terminated, and the rotation of the solid-liquid separation drum 2 and the subsequent treatment process are completed. The drainage of the filtrate W2 may be started. In addition, as an index for starting the rotation of the solid-liquid separation drum 2 and the drainage of the filtrate W2 to the subsequent processing step, it is preferable that the water head difference HD is 20 cm or more.

  In addition, since the precoat layer PC is not formed on the outer peripheral surface of the mesh material 21 of the solid-liquid separation drum 2 near the water surface on the drum immersion side 1b, the precoat layer PC is formed as the rotation speed of the solid-liquid separation drum 2 increases. The part which is not made becomes long in the circumferential direction, so that the water to be treated W1 can easily pass into the solid-liquid separation drum 2. That is, the higher the rotational speed of the solid-liquid separation drum 2, the lower the water level L1 in the processing tank 1 and the higher the water level L2 in the solid-liquid separation drum 2, so the water head difference HD becomes smaller.

  Accordingly, the water head difference HD is reduced by performing control such that the rotation speed is increased when the water level L1 is increased or the water level L2 is decreased, and conversely the rotation speed is decreased when the water level L1 is decreased or the water level L2 is increased. For example, the filtered water W2 having a stable concentration can be obtained by always maintaining approximately 20 cm.

  In addition, since the position where the solid-liquid separation drum 2 is immersed in the water by the rotation is a portion where the formation of the precoat layer PC is started, when the processing target water W1 from the water supply pipe 13 is supplied to this position, Suspended solid matter having a relatively large particle size contained in the water to be treated W1 adheres, and the precoat layer 2 is likely to be formed in a non-uniform and rough state, so that the water quality of the filtrate W2 becomes unstable. Cheap.

  On the other hand, according to the present invention, the water to be treated W1 supplied to the treatment tank 1 through the water supply pipe 13 is sent to the lowermost part of the solid-liquid separation drum 2 by the flow guide member 14 provided in the treatment tank 1. It is guided so as to be in contact with the outer periphery of the solid-liquid separation drum for the first time in the rotational direction forward, that is, at a position unevenly distributed on the drum floating side 1a. Therefore, the floating solid matter having a relatively large particle size contained in the water to be treated W1 is distributed in the treatment tank 1 on the drum floating side 1a (front of the solid-liquid separation drum 2 in the rotational direction). In the drum immersion side 1b (the rear in the rotational direction from the lowermost part of the solid-liquid separation drum 2), floating solids having a relatively small particle size are distributed.

  That is, a floating solid concentration gradient that is relatively low on the drum immersion side 1b and relatively high on the drum floating side 1a is generated in the processing target water W1 in the processing tank 1.

  Accordingly, the floating solid matter having a relatively large particle size contained in the water to be treated W1 is a solid solid having a certain thickness as the precoat layer PC moves in the clockwise direction after the formation of the precoat layer PC is started. After the lowest position of the liquid separation drum 2, it will adhere to the precoat layer PC, and floating solids having a relatively small particle size will be distributed on the drum immersion side 1b. Accordingly, since the suspended solid concentration of the water to be treated W1 is low at the position where the portion where the precoat layer PC is not formed is immersed (drum immersive side 1b), the water quality of the filtrate W2 filtered at this portion is also maintained well. The

  In addition, when the process target water W1 is an organic wastewater, the organic solid collected by the collecting means 3 can be used as a biomass resource, for example, biomass energy such as methane, hydrogen, ethanol, or compost It is possible to use. In addition, in the case of food factory wastewater that is difficult to mix with detergent or the like, the recovered biomass can be used as feed.

  In addition, when the water to be treated W1 is inorganic wastewater discharged from a product processing factory, such wastewater includes metals such as iron and copper generated by processing such as cutting and polishing, or silicon. Therefore, the inorganic solid collected by the collecting means 3 can be used as a recycled resource with high purity.

  Next, FIG. 4 is a schematic cross-sectional view showing a third form of the solid-liquid separation device by the precoat type rotating drum according to the present invention, and FIG. 5 is a VV cross-sectional view in FIG. In the third embodiment, the difference from the first or second embodiment described above is that one of the treatment tanks 1 in which the outer diameter portion of the solid-liquid separation drum 2 on the opened side is slidably contacted. A filtrate reflux tank 15 communicating with the filtrate storage chamber S on the inner periphery of the solid-liquid separation drum 2 through the drain port 12 is provided on the outside of the side wall 11, and filtered from the filtrate storage chamber S through the drain port 12. The filtrate W2 that has flowed into the water reflux tank 15 can be selectively sent to a subsequent processing step or the water supply pipe 13 by the pump 16 and the valves 17 and 18.

  Therefore, as described above, the mesh material of the solid-liquid separation drum 2 is obtained by circulating the filtrate W2 in the filtrate storage chamber S of the solid-liquid separation drum 2 to the treatment tank 1 at the initial stage of the solid-liquid separation step. The precoat layer PC can be formed on the outer peripheral surface 21, and thereafter, the filtered water W <b> 2 having a sufficiently reduced concentration can be easily switched to the subsequent processing step.

  Treatment supplied to the treatment tank 1 so that the concentration of suspended solids in the treatment target water W1 in the treatment tank 1 is relatively low on the drum immersion side 1b and relatively high on the drum floating side 1a. Means for guiding the target water W1 to a position unevenly distributed on the drum floating side 1a can be realized by supplying the target water W1 to the drum floating side 1a, for example, in addition to the flow guide member 14 described above.

  FIG. 6 is a schematic cross-sectional view showing a fourth embodiment of a solid-liquid separation device using a precoat type rotating drum according to the present invention as an example. That is, the feature of this fourth embodiment is that the water supply pipe 13 is opened near the water surface of the drum floating side 1a, and the gap G between the bottom of the treatment tank 1 and the solid-liquid separation drum 2 is made as small as possible. It is in. Other parts can be basically configured in the same manner as in FIG. 1, FIG. 2, FIG. 3, FIG.

  According to this 4th form, the process target water W1 from the water supply pipe 13 is supplied to the drum floating side 1a among the process tanks 1, and also the clearance gap between the bottom part of the process tank 1 and the solid-liquid separation drum 2 is provided. Due to the narrowness of G, the gap G allows the flow of water itself, but acts to suppress the passage of suspended solids in the water to the side opposite to the rotation direction (drum immersing side 1b). Will occur. For this reason, like each form demonstrated previously, the floating solid concentration gradient of the process target water W1 in the processing tank 1 is relatively low on the drum immersion side 1b, and becomes relatively high on the drum floating side 1a. For this reason, the floating solid matter having a relatively large particle size contained in the water to be treated W1 supplied from the water supply pipe 13 to the drum floating side 1a is distributed in the drum floating side 1a in the treatment tank 1 and is immersed in the drum. On the side 1b, suspended solids having a relatively small particle size are distributed.

  Accordingly, a drum in which the precoat layer PC has a certain thickness as the floating solid matter having a relatively large particle size contained in the water to be treated W1 moves clockwise after the formation of the precoat layer PC is started. It will adhere to the precoat layer PC on the floating side 1a, and floating solids having a relatively small particle size will be distributed on the drum immersion side 1b. For this reason, since the suspended solid concentration of the water to be treated W1 is low on the drum immersive side 1b where the portion where the precoat layer PC is not formed is immersed, the water quality of the filtrate W2 filtered in this portion is also kept good.

  According to the present invention, from organic wastewater (life wastewater, food factory wastewater, methane fermentation digestive fluid, organic sludge, etc.) and inorganic wastewater (inorganic sludge, cement wastewater, polishing / cutting wastewater, silicon processing wastewater, etc.) Because it is possible to separate and collect suspended solids without adding chemicals, it is particularly effective as a means to reduce the processing load in the latter stage by installing suspended solids in the first stage of wastewater treatment and removing suspended solids in wastewater. Can be used. Of the collected solid content, organic matter can be reused as a biomass resource, and inorganic matter can be reused by appropriate treatment, which can reduce costs for disposal and treatment.

DESCRIPTION OF SYMBOLS 1 Treatment tank 1a Drum floating side 1b Drum immersive side 12 Drain port 13 Water supply pipe 14 Flow guide member 15 Filtrate reflux tank 2 Solid-liquid separation drum 21 Mesh material 3 Recovery means 31 Roller 32, 33 Scraper PC Precoat layer S Filtrate storage Chamber W1 Water to be treated W2

Claims (7)

  A treatment tank to which water to be treated is supplied, and a solid-liquid separation drum in which the outer peripheral wall is made of a mesh material and is arranged to be rotatable around a horizontal axis while being partially immersed in the water to be treated. And a recovery means for peeling off and collecting the precoat layer made of suspended solids adhered and deposited on the outer peripheral surface of the mesh material, and a drainage means for discharging the filtrate that has passed into the solid-liquid separation drum. A solid-liquid separation device using a pre-coated rotary drum, wherein the mesh material of the liquid separation drum has an opening of 150 μm or less.   The concentration of suspended solids in the water to be treated in the treatment tank is relatively low on the side where the outer periphery of the solid-liquid separation drum immerses below the surface of the water after the precoat layer is peeled off by the collecting means along with its rotation. The outer periphery of the solid-liquid separation drum floats above the water surface so that the concentration of the water to be treated is relatively high on the side where the outer periphery of the solid-liquid separation drum floats on the water surface as it rotates. The solid-liquid separation device using a pre-coated rotary drum according to claim 1, wherein the solid-liquid separation device is led to a position that is unevenly distributed on the side to be moved.   One side in the axial direction of the solid-liquid separation drum is opened, and the outer diameter portion on the opened side is slidably in close contact with the inner side surface of one side wall of the treatment tank. 3. A filtrate reflux tank communicating with the internal space of the solid-liquid separation drum is provided, and the filtrate can be refluxed from the filtrate reflux tank to the treatment tank via a pump. Solid-liquid separator using a pre-coated rotary drum.   The water to be treated is supplied to a treatment tank of the solid-liquid separation device using the precoat type rotating drum according to any one of claims 1 to 3, and the solid-liquid is processed in a process of passing the water to be treated to the inside of the solid-liquid separation drum. A pre-coating layer is formed by adhering and depositing suspended solids contained in the water to be treated on the outer peripheral surface of the separation drum, and the water that has flowed into the internal space of the solid-liquid separation drum and the water to be treated in the treatment tank. A solid-liquid separation method, wherein the water to be treated is filtered through the precoat layer toward the internal space of the solid-liquid separation drum by a water head difference with water.   The solid-liquid separation method according to claim 4, wherein the water to be treated supplied to the treatment tank is a supernatant water from which a substance having good sedimentation properties has been removed as a pretreatment.   5. The solid-liquid separation method according to claim 4, wherein the water to be treated supplied to the treatment tank is suspension water obtained by previously pulverizing suspended solids in water to form a slurry.   At the initial stage of the solid-liquid separation process, the filtrate that has flowed into the internal space of the solid-liquid separation drum is circulated by refluxing it to the treatment tank, thereby forming a precoat layer on the outer peripheral surface of the mesh material of the solid-liquid separation drum. The drained water is drained when the head difference between the filtered water in the internal space of the liquid separation drum and the water to be processed in the processing tank reaches a predetermined value. The solid-liquid separation method described in 1.

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