JP2018158322A - Sludge filtration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge filtration apparatus capable of effectively infiltrating a sludge with an agent when an agent is added to sludge put into a gravity filtration part.SOLUTION: In order to solve the above problem, in a sludge filtration apparatus having a gravity filtration part for dehydrating sludge by gravity filtration, the gravity filtration part comprises a roughening plate for forming irregularities on the surface of the sludge, a latter stage of the roughening plate and an agent adding portion for adding an agent to the sludge filtration apparatus. Since irregularities are formed on the surface of the sludge by the roughening plate, the surface area becomes large and the agent can be permeated efficiently.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sludge filtration device for dewatering sludge. More specifically, the present invention relates to a sludge filtration device including a gravity filtration unit that dewaters sludge by gravity filtration.

  2. Description of the Related Art As a device for dewatering sludge generated at a sewage treatment plant or the like, a sludge filtration device including a filtration unit that gravity-filters sludge on the upper surface of a filter medium belt traveling on an endless track is known. In addition, a configuration in which a chemical is added to sludge put on the filter medium belt is also known.

  For example, in Patent Document 1, in a sludge concentration / dehydration apparatus provided with a filter body that travels in an endless track, a plurality of rod bodies for promoting drainage of sludge are erected on the upper surface of the filter body, and downstream thereof. The structure which provided the chemical | medical agent addition equipment for adding a chemical | medical agent to the side is described.

JP 2013-180262 A

In the apparatus described in Patent Document 1, sludge forms a soot on the downstream side of the rod, and the filter medium is exposed between the soot and the soot. Therefore, when a chemical | medical agent is added in the downstream of a rod, a chemical | medical agent may fall on the filter medium surface, and the chemical | medical agent loss arises. Moreover, since the height of the soot becomes higher than the height of the sludge before passing through the rod, there is a problem that the chemical added to the soot is difficult to penetrate to the deep part of the sludge.
Therefore, an object of the present invention is to effectively infiltrate the chemical into the sludge introduced into the gravity filtration unit.

As a result of earnestly examining the above problems, the present inventor has provided a roughening plate for forming irregularities on the surface of the sludge in the gravity filtration portion, and a chemical addition portion for adding the chemical at the subsequent stage of the roughening plate. The present invention has been completed by discovering that the drug can be effectively penetrated with respect to the above.
Specifically, it is the following sludge filtration device.

  The sludge filtration device of the present invention for solving the above-mentioned problems is a sludge filtration device provided with a gravity filtration portion that dewaters sludge by gravity filtration, wherein the gravity filtration portion is a roughening plate that forms irregularities on the surface of the sludge. And a drug addition unit for adding a drug at the subsequent stage of the roughening plate.

According to this sludge filtration device, the surface area of the sludge can be increased by forming irregularities on the surface of the sludge, and the drug can be effectively permeated into the sludge by adding the drug there.
Moreover, since the chemical | medical agent is not added with respect to the filter medium surface of the exposed state, the sludge filtration apparatus of this invention has the effect that the loss of a chemical | medical agent can be prevented.

Furthermore, in one embodiment of the present invention, the drug is characterized by being an aggregating agent.
According to this feature, the flocculant effectively penetrates into the sludge as a chemical agent, so that the dewatering efficiency of the sludge can be increased.

Furthermore, in one embodiment of the present invention, there is a feature that a ridge is provided in the front stage of the roughening plate or the rear stage of the chemical addition section.
When the soot is provided in the front stage of the roughening plate, the sludge is concentrated by the soot, so that the uneven shape of the sludge surface formed by the roughening plate is maintained.
In addition, when a soot is provided at the subsequent stage of the medicine adding portion, the sludge to which the medicine has been added is kneaded by the soot, so that there is an effect of promoting the penetration of the medicine.

  According to the present invention, in the sludge filtration device provided with a gravity filtration unit for dewatering sludge by gravity filtration, the gravity filtration unit is provided with a roughening plate that forms irregularities on the surface of the sludge, and a chemical agent at a subsequent stage of the roughening plate. By providing the chemical | medical agent addition part to add, a chemical | medical agent can be osmose | permeated effectively with respect to sludge.

It is a schematic explanatory drawing which shows the structure of the sludge filtration apparatus of the 1st embodiment of this invention (side view). It is a schematic explanatory drawing which shows the structure of the gravity filtration part of the sludge filtration apparatus of the 1st embodiment of this invention (a side view and a top view). It is a schematic explanatory drawing which shows the structure of the various embodiment of the roughening board of this invention (side view). It is a schematic explanatory drawing which shows the structure of the other embodiment of the roughening board of this invention. FIG. 4A is a side view showing the structure of another embodiment of the roughening plate of the present invention. [FIG. 4B] It is a schematic explanatory drawing which shows the shape of the protrusion part of the contact surface of the other embodiment of the roughening board of this invention (bottom view). [FIG. 4C] It is a schematic explanatory drawing (side view) which shows the shape of the protrusion part of the contact surface of the other embodiment of the roughening board of this invention. It is a schematic explanatory drawing which shows the structure of the other embodiment of the roughening board of this invention. FIG. 5A is a schematic explanatory view (side view) showing the structure of another embodiment of the roughening plate of the present invention. [FIG. 5B] It is a schematic explanatory drawing which shows the structure of the contact part of the other embodiment of the roughening board of this invention (front view). It is a schematic explanatory drawing which shows the structure of the other embodiment of the roughening board of this invention (side view). It is a schematic explanatory drawing which shows the structure of each component which comprises the chemical | medical agent addition part of the sludge filtration apparatus of the 1st embodiment of this invention. [FIG. 7A] It is a schematic explanatory view showing the structure of the overflow weir of the drug addition section (front view). FIG. 7B is a schematic explanatory view showing the structure of the medicine receiving tank and the medicine supply pipe of the medicine addition section (front view). [FIG. 7C] It is a schematic explanatory view showing a structure when the overflow weir, the medicine receiving tank, and the medicine supply pipe of the medicine addition section are assembled (side view). It is a schematic explanatory drawing which shows the structure of the gravity filtration part of the sludge filtration apparatus of the 2nd embodiment of this invention (a side view and a top view). It is a result of Examples 1-5 of sludge dehydration by the sludge filtration apparatus of the present invention. It is a photograph which shows the state of the sludge after passing the roughening board of the sludge filtration apparatus of this invention. It is a photograph which shows the state of the sludge which has not passed the vandalism board.

  The sludge filtration device of the present invention includes a gravity filtration unit that dewaters sludge by gravity filtration, and the gravity filtration unit adds a chemical to a roughening plate that forms irregularities on the surface of the sludge, and a subsequent stage of the roughening plate. A drug addition unit.

  The sludge of the present invention may be any dispersion liquid or mud substance in which particulate solid is dispersed in a liquid. For example, sludge generated at a sewage treatment plant or a wastewater treatment plant, papermaking sludge from a paper mill, factory wastewater from a food factory or plating factory, pigment wastewater, and the like. Moreover, if it is the concentration process using a chemical | medical agent, you may utilize for the refinement | purification of a foodstuff, a pharmaceutical, etc.

  The sludge filtration device of the present invention may be provided with various pressure dehydration units that separate particulate solids and liquids contained in the sludge and further concentrate the solids after the gravity filtration unit. For example, a belt press, a screw press, centrifugation, etc. are mentioned.

  Hereinafter, embodiments of the sludge filtration apparatus according to the present invention will be described in detail with reference to the drawings. In the following embodiments, an example of a belt press apparatus is shown as the pressure dehydrating unit, but the present invention is not limited to this.

[First Embodiment]
[Sludge filtration equipment]
FIG. 1 is a schematic explanatory view showing the structure of a sludge filtration apparatus 1 according to the first embodiment of the present invention. FIG. 2 is a side view and a plan view showing the structure of the gravity filtration unit 2 according to the first embodiment of the present invention.
The sludge filtration device 1 according to the first embodiment includes a gravity filtration unit 2, and the gravity filtration unit 2 throws the sludge S into a belt-like filter medium 5 supported by a plurality of support rollers 4 and the upper surface of the filter medium 5. The introduction part 6, installed after the introduction part 6, the roughening plate 7 for forming irregularities on the surface of the sludge S, installed after the roughening board 7, the chemical addition part 8 for adding the chemical G, and the chemical addition part 8 It is installed in the latter stage and is equipped with a bowl 9 for kneading the sludge S and the chemical G.
In addition, in the sludge filtration apparatus 1 of the 1st embodiment of this invention, the pressurization dehydration part 3 is provided in the back | latter stage of the gravity filtration part 2, as shown in FIG.

Each configuration will be described in detail below.
[Belt-shaped filter media]
The belt-shaped filter medium 5 is configured to convey and filter the sludge S.
As shown in FIG. 1, a belt-shaped filter medium 5 is supported by a plurality of support rollers 4. The support roller 4 is rotatable and is configured such that the filter medium 5 travels. When the sludge S is supplied onto the filter medium 5, the filtrate falls and is concentrated while the filter medium 5 is traveling.

The belt-shaped filter medium 5 may be a belt-shaped filter device that travels in a substantially horizontal direction, and examples thereof include a belt-shaped filter cloth. The belt-shaped filter cloth is lightweight and easy to handle, and can be used in a belt press dehydrator that is one of the pressure dewatering units 3 in cooperation with another endless belt.
The material of the filter cloth is not particularly limited, and examples thereof include synthetic fibers such as nylon and polyester, and metal meshes such as cotton and stainless steel.

[Input section]
The input unit 6 is configured to input the sludge S onto the filter medium 5.
As shown in FIG. 2, it is comprised by the U-shaped sludge receiving tank 6b opened toward the conveyance direction front of the filter medium 5, and the sludge supply pipe 6a which supplies the sludge S in the sludge receiving tank 6b. Furthermore, a weir 6c is provided on the opening side of the sludge receiving tank 6b to form a pool portion in which the sludge S is accumulated. The weir 6c in the sludge filtering device 1 of the first embodiment is configured by a plate material that is installed so as to be rotatable about the upstream end with respect to the conveying direction of the filter medium 5, and the lower end of the weir 6c is rotated. By doing so, the sludge S flows out from the pool part. By providing the pool portion, the sludge S can be evenly spread in the width direction of the filter medium 5.

  The structure of a pool part should just be the structure which accumulates the sludge S supplied from the sludge supply pipe | tube 6a on the filter medium 5. FIG. For example, a configuration in which a weir standing on the filter medium 5 is provided and the sludge S overflows the weir, or a sludge receiving tank 6b is installed on an inclined surface of the inclined filter medium 5, and is surrounded by the inclined surface and the sludge receiving tank 6b. The structure etc. which accumulate sludge S are mentioned.

  Note that the input unit 6 may have any configuration as long as the sludge S is supplied onto the filter medium 5, and may have only a sludge supply pipe 6 a and no pool unit. From the viewpoint of uniformly feeding in the width direction of the filter medium 5, a feeding part having a pool part is preferable.

[Trolling board]
The roughening plate 7 has a contact portion that comes into contact with the sludge S introduced into the filter medium 5 from the input portion 6, and is configured to make the surface of the sludge S uneven.
As shown in FIGS. 1 and 2, the roughening plate 7 is a plate member that is installed so as to be rotatable about an upstream end portion with respect to the conveying direction of the filter medium 5, and the downstream end portion of the plate member is Refracted in the conveying direction of the filter medium 5.

By making the roughening plate 7 turnable, there is no fear that the sludge S is blocked by the roughening plate 7 and clogged. Moreover, there is an effect that the height of the contact portion can be changed according to the height of the sludge S.
In addition, the roughening board 7 is good also as a structure fixed without rotating.

Next, the action of the roughening plate 7 will be described in detail.
The concentration of the sludge S introduced into the introduction unit 6 is increased by gravity filtration while being conveyed by the belt-shaped filter medium 5. When the sludge S that has risen to a predetermined concentration comes into contact with the roughening plate 7, movement of the surface of the sludge S is restricted by the contact portion, and a convex portion is formed on the surface of the sludge S. If this convex part becomes a predetermined | prescribed magnitude | size, the load concerning the roughening board 7 will increase, the roughening board 7 will rotate, and a convex part will pass. By repeating this operation, irregularities are formed on the surface of the sludge S.

  The concentration of the sludge S provided to the roughening plate 7 is not particularly limited, but is preferably 1.5% by mass or more, more preferably 2% by mass, still more preferably 3% by mass, and particularly preferably 4% by mass. %. Moreover, as an upper limit, Preferably it is 10 mass%, More preferably, it is 7 mass%, Especially preferably, it is 6 mass%. When the concentration of the sludge S is small, the unevenness formed by the roughening plate 7 tends to disappear. On the other hand, when the concentration of the sludge S is high, the sludge S becomes hard and the unevenness is not easily formed by the roughening plate 7. It becomes.

  The position where the roughening plate 7 is installed may be appropriately set according to the concentration of the sludge S in consideration of the action mechanism in which irregularities are formed on the surface of the sludge S.

The structure of the roughening plate 7 may be any shape as long as the surface of the sludge S can be made uneven. For example, as in the sludge filtering device 1 of the first embodiment, a curved plate or a flat plate may be used in addition to a refracted plate. Moreover, as a structure contact | abutted with the surface of a roughening board and sludge S, the surface of a board | plate material other than the structure contact | abutted with sludge S in the refracting part of the refracted board | plate material like the sludge filtration apparatus 1 of 1st Embodiment, Examples include a configuration in which the surface of the sludge S abuts and a configuration in which the sludge S abuts at the end of the flat plate. Furthermore, you may provide the projection part which accelerates | stimulates formation of an unevenness | corrugation in the contact part or contact surface which contact | abuts the surface of the sludge S.
Specific examples of various structures of the roughening plate are shown in FIGS. In addition, although all the roughening plates mentioned in the specific examples are configured to be rotatable, they may be fixed without being rotated.

  FIG. 3A is an enlarged view of the roughening plate 7 of the sludge filtration device 1 according to the first embodiment. The roughening plate 7 is made of a plate material refracted in the transport direction, and contacts the sludge S at the refracting portion. Further, as shown in FIG. 3A, when the roughening plate 7 and the sludge S come into contact with each other, the end portion of the roughening plate 7 is inclined obliquely upward. According to this structure, since sludge S is wound up in the conveyance direction diagonally upward direction, formation of unevenness can be promoted.

  Further, as shown by the dotted line in FIG. 3A, the roughening plate 7 has a filter medium 5 with the plate surface at the tip of the refracting portion when the sludge S is not treated or when the amount of sludge S is extremely small. It is comprised so that it may become substantially parallel. According to this structure, since the edge part of the roughening board 7 does not contact the filter medium 5, there exists an effect that the filter medium 5 is not damaged.

  FIG. 3B is a schematic explanatory view showing a roughening plate 71 made of a plate material curved in the conveying direction of the sludge S. Similar to the roughening plate 7 illustrated in FIG. 3A, the roughening plate 71 also has an action of winding up the sludge S in the conveying direction obliquely upward to promote the formation of irregularities. Moreover, since the edge part of the roughening board 71 does not contact the filter medium 5, there exists an effect that the filter medium 5 is not damaged.

FIG. 4 is a schematic explanatory view showing the structure of the roughening plate 72 having an abutting surface 7a that abuts against the surface of the sludge S. As shown in FIG. According to the roughening plate 72, friction is generated between the abutting surface 7a and the surface of the sludge S, so that the movement of the surface of the sludge S is temporarily restricted to form irregularities.
Further, as shown in FIG. 4B, the contact surface 7 a may be provided with a protrusion for making it easier to form irregularities on the surface of the sludge S. Specific examples of the protrusion include a plurality of plate-like protrusions (upper left or upper right in FIG. 4B) parallel or perpendicular to the sludge S conveying direction, or a plurality of triangular pyramid-like protrusions such as a grater. (The lower left figure of FIG. 4B) may be sufficient.

  Furthermore, the height of the protrusions is not necessarily constant, and may be regular or irregular. For example, as shown in the left diagram of FIG. 4C, a configuration having a protrusion having a certain height, a configuration in which the projection increases in the sludge S conveying direction, as shown in the center diagram of FIG. As shown in the figure, a configuration in which protrusions having different heights are alternately arranged can be used.

FIG. 5 is a schematic explanatory view showing the structure of the roughening plate 73 made of one flat plate. In this roughening plate 73, as shown in FIG. 5A, an end portion of the flat plate constitutes a contact portion 7b in contact with the surface of the sludge S.
According to this structure, since it is a rough plate of a simple shape, there exists an advantage that there are few labors, such as a process.

  The roughening plate 73 is inclined at an angle of about 50 ° from the vertically downward direction toward the conveying direction of the sludge S. By inclining, the area in contact with the surface of the sludge S becomes large, so that there is an effect that friction is easily generated and irregularities are easily formed. From the viewpoint of excellent formation of unevenness, the angle formed with the vertical direction (“θ” in FIG. 5A) is preferably 30 to 60 °.

  In addition, as shown in FIG. 5B, the contact portion 7 b may be provided with a plurality of protrusions for making it easier to form irregularities on the surface of the sludge S.

  FIG. 6 is a schematic explanatory view showing the structure of the roughening plate 74 having a configuration in which the contact surface 7a with the sludge S and the end portion are inclined obliquely upward. As shown in FIG. 6, the roughening plate 74 is a combination of the structures shown in FIGS. 3 and 4, and the operation of each structure is as described above.

[Drug addition part]
The drug addition unit may have any configuration as long as the drug G is dripped onto the sludge S. For example, the drug receiving tank having an overflow weir as in the drug addition unit 8 of the first embodiment. In addition to the configuration in which the drug G is dropped from the overflow weir, the supply pipe having a plurality of holes may be used, and the drug G may be dropped from the holes. In the configuration including the medicine receiving tank having the overflow weir, there is an effect that the medicine G can be dropped evenly in the width direction of the overflow weir.

  As shown in FIG. 2, the drug addition unit 8 is installed at the rear stage of the roughening plate 7. Thereby, since the chemical | medical agent G is dripped at the surface of the sludge S in which the unevenness | corrugation was formed by the roughening board 7, the chemical | medical agent G tends to osmose | permeate the sludge S.

  The width of the drug addition unit 8 is not particularly limited, but it is preferable that the drug addition unit 8 is installed over the entire width of the sludge S in order to drop the chemical solution of the drug G on the entire sludge S.

  Moreover, it is preferable to install the chemical | medical agent addition part 8 in the orthogonal | vertical direction with the conveyance direction of the filter medium 5. FIG. Thereby, since the permeation time to the sludge S after dropping the drug G is constant in the width direction of the sludge S, the permeation state of the drug G in the width direction of the sludge S becomes uniform.

  In addition, you may install two or more chemical | medical agent addition parts with respect to the conveyance direction of the sludge S. In the case where a plurality of drug addition units are installed, a plurality of drug addition units may be installed after the roughening plate, or may be installed before and after the roughening plate. Further, a plurality of roughening plates may be provided, and the roughening plates may be provided in front of the respective drug addition portions. By installing a plurality of drug addition units, the drug G can be more efficiently permeated into the sludge S.

  FIG. 7 is a schematic explanatory view showing the structure of the drug addition unit 8 of the first embodiment. As shown in FIG. 7 c, the drug addition unit 8 includes a drug receiving tank 10 formed of a rectangular container having an open front surface, a plate-shaped overflow weir 11 attached to the opening, and a drug that supplies the drug G into the drug receiving tank 10. A supply pipe 12 is used.

  The medicine G supplied from the medicine supply pipe 12 is accumulated in the medicine receiving tank 10, and when the water level of the medicine G exceeds the height of the overflow weir 11, it overflows the overflow weir 11 from the medicine addition unit 8. Dripping down. Thus, since the chemical | medical agent G is widely distributed in the width direction of the overflow weir 11, the chemical | medical agent G can be added over the wide range of the sludge S. FIG. In addition, since a certain amount of medicine G is stored inside the medicine receiving tank 10, the medicine adding section 8 does not dry inside even if the amount of the chemical solution added is small.

  FIG. 7A is a front view showing the structure of the overflow weir 11. As shown in FIG. 7A, the overflow weir 11 has an overflow portion 11a formed of a triangular cutout formed at the upper end of the overflow weir 11, and a groove formed so as to hang down from the overflow portion 11a. A triangular projecting portion 11c projecting from the bottom at the position of the water channel 11b and the water channel 11b is formed.

  The overflow portion 11 a is a portion where the drug G overflows in the overflow weir 11, and includes a plurality of cutout portions formed at the upper end of the overflow weir 11. By providing the plurality of overflow portions 11a, even when the amount of the drug G added is small, it can be evenly distributed in the width direction of the overflow weir.

  The water channel 11b is a structure for the medicine G which overflowed to flow down the surface of the overflow weir 11 vertically. When the added amount of the drug G is small, the drug G may diffuse and dry when flowing down the surface of the overflow weir 11. By providing the water channel 11b, drying of the chemical | medical agent G on the surface of the overflow weir 11 can be suppressed, and dripping amount can be made constant.

  The protruding portion 11 c is configured to protrude from the bottom of the overflow weir 11. When the medicine G reaches the bottom of the overflow weir 11, it spreads in the width direction of the overflow weir 11, and may dry at the bottom. By providing the projecting portion 11c, diffusion of the medicine G at the bottom can be suppressed.

[Drug]
The drug G of the present invention may be any substance as long as it is generally used for treating sludge. For example, an acid, an alkali, a flocculant, etc. are mentioned. The drugs may be used alone or in combination of two or more. When two or more types are used, they may be used in combination, or a plurality of drug addition units 8 may be provided and different drugs may be used in order.

  When the drug G is solid, it is dissolved or dispersed in a solvent and used as a liquid. As the solvent, a hydrophilic solvent such as water or ethanol can be used.

Examples of the acid include sulfuric acid, hydrochloric acid, nitric acid, acetic acid, formic acid, phosphoric acid and the like.
Examples of the alkali include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, lithium carbonate, sodium carbonate, and potassium carbonate. Alkaline metal carbonates, alkaline earth metal carbonates such as calcium carbonate, organic amines such as ammonia, monoethanolamine, diethanolamine, and triethanolamine, inorganic substances that exhibit alkalinity by mixing with water such as cement paste and lime paste A mixture etc. are mentioned.

  Furthermore, the drug G of the present invention is desirably an aggregating agent. The flocculant may be any substance as long as it has an aggregating action. Examples thereof include cationic, nonionic, anionic and amphoteric flocculants, which are appropriately selected according to the processing conditions. In the present invention, it is particularly preferable to use an inorganic flocculant as the drug G. Since the inorganic flocculant exhibits a certain flocculation effect even if it is not completely mixed with sludge, the effect of the present invention is more exhibited.

Examples of cationic flocculants include inorganic flocculants such as polyferric sulfate, ferric chloride, polysilica iron, polyaluminum chloride, polyaminoalkyl methacrylate, polyethyleneimine, polydiallylammonium halide, chitosan, urea-formalin. Examples thereof include a polymer flocculant such as a resin.
Examples of nonionic flocculants include polyacrylamide and polyethylene oxide.
Examples of the anionic flocculant include sodium polyacrylate, polyacrylamide partial hydrolyzate, partially sulfomethylated polyacrylamide, poly (2-acrylamide) -2-methylpropane sulfate, and the like.
Examples of amphoteric flocculants include copolymers of acrylamide, aminoalkyl methacrylate and sodium acrylate.

〔plow〕
The scissors 9 are provided in the front stage of the roughening plate 7 or in the rear stage of the drug addition unit 8. The eaves 9 are made of a rod body installed on the upper part of the filter medium 5 and have an action of narrowing the course of the sludge S.
When the eaves 9 are erected on the front stage of the roughening plate 7, the sludge S is compressed by narrowing the course of the sludge S, so that the sludge S is concentrated. If the amount of water in the sludge S is large, the effect of the roughening plate 7 is reduced, and even if the chemical G is added, the chemical G remains on the surface of the sludge S and does not penetrate into the sludge. By providing the flange 9 in the previous stage, the effect of the present invention can be further enhanced.

  Further, when the bowl 9 is installed at the rear stage of the chemical addition section 8, the sludge S is divided into a plurality of parts in the width direction by narrowing the course of the sludge S, so the sludge S to which the chemical G is added is kneaded. The effect of doing. Thereby, the sludge S and the chemical | medical agent G are mixed more uniformly.

  The number of the eaves 9 is not particularly limited, but it is preferable to install a plurality of the eaves 9 in the width direction and / or the conveyance direction of the sludge S in consideration of the concentration property or kneading property.

  The shape of the bowl 9 may be any shape as long as the sludge S is concentrated and kneaded. For example, a cylindrical shape, a prismatic shape, a flat plate shape and the like can be mentioned. In consideration of the action of narrowing the path of the sludge S, it is preferable that the width is increased in the direction in which the sludge S is conveyed.

[Second Embodiment]
FIG. 8 is a side view and a plan view showing a structure in which the roughening plate 7 and the two drug addition portions 8 are provided in the gravity filtration portion 2 as the sludge filtration device 1 of the second embodiment of the present invention.
Furthermore, in the sludge filtration apparatus 1 of the second embodiment, a bowl 9 is provided after the first-stage chemical addition unit 8, and the chemical G is further kneaded with the sludge S.

As Examples 1 and 2, the sludge S was dehydrated using the sludge filtration apparatus 1 having the gravity filtration part 2 of the first and second embodiments shown in FIGS. 2 and 8, respectively.
Moreover, as Example 3, what provided the chemical | medical agent addition part 8 in the upstream and downstream of the roughening board 7 was used, and in Example 4, the chemical | medical agent addition part 8 was provided in the upstream and downstream of the roughening board 7, and upstream What provided the ridge 9 between the side chemical | medical agent addition part 8 and the roughening board 7 was used.
Furthermore, as Example 5, in addition to the configuration of Example 2, a drug addition unit 8 was further provided on the most upstream side, and the drug addition unit 8 was provided at three locations.

  The operating conditions are as follows. Filtration rate, 60 kgDS / m / h or 90 kgDS / m / h (upper / lower of the table in FIG. 9). The drug injection rate was 2.3%. Polyiron injection rate 20%. In addition, in the sludge filtration apparatus 1 provided with the some chemical | medical agent addition part 8, a chemical | medical agent was divided | segmented equally and added.

  In FIG. 9, the result of the said Examples 1-5 is shown. In any of the examples, the water content was less than 80% by mass, and the concentrated concentration of sludge was 6% by mass or more, and an excellent dehydrating effect was recognized.

Furthermore, when Example 1 and Example 2 were compared, the especially outstanding dehydration effect was recognized by installing the roughening board 7 and the chemical | medical agent addition part 8 in multiple numbers.
In addition, the state of the sludge after passing through the 2nd-stage roughening board 7 of Example 2 is shown in FIG. When FIG. 10 is seen, after passing the roughening board 7, it turns out that the unevenness | corrugation is formed in the sludge surface.

Moreover, when Example 1 was compared with Example 3 and Example 4, the superior dehydration effect of Example 1 was recognized. In Example 3 and Example 4, the drug was added in two portions, and one was added at the front stage of the roughening plate 7. The state of the sludge in the previous stage of the roughening plate 7 has a concentration of less than 3% by mass, and no irregularities are formed by the roughening plate 7.
In addition, the state of the sludge after passing the chemical | medical agent addition part 8 of the 1st step | paragraph of Example 4, and the soot 9 is shown in FIG. When FIG. 11 is seen, the penetration effect of a chemical | medical agent is small, and it turns out that the chemical | medical agent G remains on the sludge surface in strip | belt shape.

  When Example 2 and Example 5 were compared, when the filtration rate was 60 kg DS / m / h, the water content was equivalent, but when the filtration rate was 90 kg DS / m / h, Example 2 The better dehydration effect was observed. In Example 5, the drug was added in three portions, and the first-stage addition was added before the roughening plate 7. The state of sludge in the previous stage of the roughening plate 7 is that the concentration concentration is 3% by mass or more when the filtration rate is 60 kgDS / m / h, and the concentration concentration is when the filtration rate is 90 kgDS / m / h. It is less than 2% by mass, and in any case, the unevenness is not formed by the roughening plate 7.

The sludge filtration device of the present invention can be suitably used for sludge dewatering treatment. For example, it can be used for dewatering treatment of various sludges generated in water treatment plants such as sewage treatment plants and wastewater treatment plants, food factories, plating factories, paper mills, dredging work sites, construction work sites, and the like.
Moreover, as long as it is a dehydration process that separates a solid and a liquid using a drug, it may be used for any process, and for example, it may be used for the purification of food or medicine.

DESCRIPTION OF SYMBOLS 1 Sludge filtration apparatus, 2 Gravity filtration part, 3 Pressure dehydration part, 4 Support roller, 5 Filter medium, 6 Input part, 6a Sludge supply pipe, 6b Sludge receiving tank, 6c Weir, 7, 71, 72, 73, 74 7a contact surface, 7b contact part, 8 drug addition part, 9 鋤, 10 drug receiving tank, 11 overflow dam, 11a overflow part, 11b water channel, 11c projecting part, 12 drug supply pipe, S sludge, G Drug

Claims (3)

In the sludge filtration device equipped with a gravity filtration part that dewaters sludge by gravity filtration,
The said gravity filtration part is equipped with the roughening board which forms an unevenness | corrugation on the surface of sludge, and the chemical | medical agent addition part which adds a chemical | medical agent in the back | latter stage of the said roughening board, The sludge filtration apparatus characterized by the above-mentioned.   The sludge filtration apparatus according to claim 1, wherein the chemical is a flocculant. The sludge filtration apparatus according to claim 1 or 2, wherein a ridge is provided at a front stage of the roughening plate or a rear stage of the chemical addition unit.