TWI539988B - Sludge dewatering treatment methods and systems - Google Patents

Description

Slurry dewatering treatment method and system

The present invention relates to a method and system for dewatering treatment of muddy water generated mainly in dredging works of dam lakes, harbors, rivers, tunnel excavation works, and the like.

A mixture of water, clay, sludge, etc. (hereinafter referred to as "mud water") generated by a dredging project of a dam, a harbor, a river, a river, a tunnel excavation, etc., is separated into a dewatered cake by a dehydration treatment device. Specifically, in the agglutination reaction tank, the slurry water and the aggregating agent are stirred and mixed to form a floc, and agglomerated muddy water is formed, and the agglomerated water supplied to the filter cartridge of the screw filter is used. The rotation of the spiral blade in the filter cartridge is pressed and dehydrated while being conveyed in the filter cartridge to form a dewatered cake.

When the agglutinated mud water is directly supplied from the agglutination reaction tank to the screw press, the water content of the aggregated mud water supplied to the screw press is too high because the draining is insufficient. Therefore, at the feed port of the screw filter, there is a possibility that water which cannot be filtered by the portion of the filter cartridge in the vicinity thereof is accumulated therein, thereby causing a decrease in the processing efficiency of the screw filter. Further, the moisture in the agglutinated mud water is also transferred to the screw press to the discharge port. Therefore, the moisture content of the resulting de-peel cake is high, and there is a problem that the strength is not good and cannot be reused.

Therefore, the technique disclosed in Patent Document 1 is a method in which the agglutinated water is supplied to the screw press before the draining is performed by the drain conveyor.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3924738

However, according to the method disclosed in Patent Document 1, the moisture content of the produced dewatered cake changes with the change of the muddy water concentration at the place of occurrence, and thus it is impossible to stably obtain a de-cement cake of a certain strength.

The present invention has been made in view of the above problems, and an object thereof is to provide a method and system for dehydrating a muddy water which can stably obtain a de-cement cake having a certain strength.

In the method for dehydrating muddy water according to the first aspect of the invention, the mixture is added to the strength-increasing material of the de-cement cake produced by the muddy water, and the mixture is reacted with the coagulant in the agglutination reaction tank to form agglomerated muddy water. After the agglomerated mud water is drained by a rotating tubular screen machine, and then subjected to press dewatering by a screw press to produce a dewatering treatment method for the dewatered cake having a predetermined moisture content, characterized in that: The content of the strength-increasing material and the boundary moisture content of the de-cement cake obtained by the specifications of the screw filter are used to determine the optimum rotation speed of the spiral blade of the screw filter, and the spiral is obtained. The amount of processing per unit time of the agglomerated mud water in the screw press when the blade is rotated at the most appropriate rotation speed, and the method of supplying the aggregated mud water per unit time to the screw press machine And reacting the plurality of mixtures in which the aggregating agent is different from the content of the strength increasing material and the concentration of the mud water. The plurality of generated agglomerated muddy waters are supplied to the cylindrical screen machine, and the most suitable one of the above-described cylindrical screen machines for performing the draining of the aggregated mud water is obtained in advance for each concentration of the muddy water. The rotation speed is used as a data, and the rotation of the spiral blade of the screw filter is controlled by rotating at the most appropriate rotation speed, and the content of the strength-increasing material is determined by referring to the above-mentioned data. Controlling the rotational driving of the cylindrical screen machine by the most appropriate rotational speed of the cylindrical screen machine of the concentration of the muddy water, and rotating the most appropriate rotational speed determined by the The optimum rotation speed is such that the drainage ratio when the cylindrical screen machine is rotated and the processing amount per unit time of the agglutinated water when the screw filter is rotated at the most appropriate rotation speed are controlled by the agglutination described above. The supply amount per unit time of the agglutinated water supplied to the cylindrical screen machine by the reaction tank.

According to the first aspect of the present invention, the supply amount per unit time of the rotary driving of the tubular screen machine and the agglutinated water supplied to the tubular screen machine is controlled in accordance with the content rate of the strength increasing material and the concentration of the muddy water. Therefore, the moisture content of the aggregated mud water supplied to the screw filter can be kept constant without being affected by the content of the strength-increasing material and the concentration of the muddy water. Therefore, the dewatered cake discharged from the screw filter has a predetermined moisture content and a certain strength.

In addition, the limit moisture content of the de-cement cake according to the content of the strength-increasing material and the specification of the screw filter is determined by a single meaning (only one interpretation), and the water content of the dewatered cake is determined according to the obtained water content. Rate, to determine the most appropriate rotational speed of the helical blade of the screw filter. Then, the rotational driving of the screw press is controlled so as to rotate at the most appropriate rotational speed obtained. Therefore, the de-cemented cake discharged from the screw press has the necessary strength and is suitable for reuse.

In addition, the data to be referred to when determining the optimum rotational speed of the discharge screen machine is a plurality of types of products which are obtained by reacting a plurality of mixtures in which the concentration of the aggregating agent and the strength-increasing material are different from the concentration of the muddy water. The agglomerated mud water is actually supplied to the cylindrical screen machine, and the optimum rotation speed of the most suitable cylindrical screen machine for performing the drainage of the agglomerated mud water is obtained in advance for each muddy water concentration. Therefore, even if the concentration of the muddy water changes, the optimum rotation speed of the discharge type screen machine can be easily determined.

In addition, the control ratio is controlled based on the draining ratio when the tubular screen machine is rotated at the most appropriate rotation speed and the processing amount per unit time of the agglutinated mud when the screw filter is rotated at the most appropriate rotation speed. The amount of supply per unit time of the agglomerated mud water supplied to the cylindrical screen machine by the agglutination reaction tank. Therefore, the processing power can be maximized.

Moreover, in the first aspect of the invention, a mixture in which the strength-increasing material of the de-cement cake produced from the muddy water is added to the muddy water is produced in the agglutination reaction tank. Therefore, the strength of the resulting de-cement cake can be moderately increased, and the de-cement cake having the strength suitable for reuse can be stably produced.

Further, in the first aspect of the invention, the strength increasing material contains at least one of sand, fly ash, slag, and cement.

The muddy water dehydration treatment system according to the second aspect of the present invention is characterized in that it comprises a coagulation reaction tank and a strength increasing material in a mixture of a coagulant and a strength-increasing material to which a dewatered cake produced by mud water is added. The plurality of mixtures having different contents and the concentration of the muddy water react to form aggregated muddy water; the muddy water concentration detecting unit detects the concentration of the muddy water; and the strength increasing material content detecting unit detects the content of the strength increasing material in the mixture. The tubular screen machine rotates to drain the agglomerated mud water generated by the agglutination reaction tank; the tubular screen machine control unit controls the cylinder according to the concentration of the mud water detected by the muddy water concentration detecting unit. The rotary driving of the screen machine; the agglomerated mud water supply amount control unit controls the supply amount per unit time of the aggregated mud water supplied from the agglutination reaction tank to the cylindrical screen machine; the screw filter press is for the above-mentioned cylinder type The screen machine performs the dewatering of the agglutinated water after draining to produce a dewatered cake having a predetermined moisture content; the data storage unit, The data stored in the data storage unit is: first, the spiral of the screw filter is determined based on the boundary moisture content of the de-cement cake obtained from the content of the strength-increasing material and the specification of the screw filter. The optimum rotation speed of the blade, and the amount of processing per unit time of the agglutinated water in the screw press when the spiral blade is rotated at the most appropriate rotation speed is obtained, to process the amount per unit time a method in which the agglutinated mud water is supplied to the screw filter, and a plurality of kinds of aggregated mud water generated by reacting the plurality of mixtures in which the concentration of the agglomerating agent and the concentration of the strength increasing material and the concentration of the mud water are different are supplied to the cylindrical screen. The most suitable rotation speed of the above-mentioned cylindrical screen machine for performing the leaching of the agglomerated mud water for each concentration of the muddy water; the screw filter control unit controls the aforementioned screw filter press The rotary drive; the control unit of the tubular screen machine refers to the data stored in the data storage unit, and the intensity is increased according to the foregoing The content rate of the strength increasing material detected by the material content detecting unit and the concentration of the mud water detected by the mud water concentration detecting unit determine the optimum rotation speed of the tubular screen machine, and the most determined rotation rate Controlling the rotational driving of the cylindrical screen machine by rotating at an appropriate rotational speed, the agglutinated mud water supply amount control unit is configured to drain the tubular screen machine at the most appropriate rotational speed. The ratio and the processing capacity per unit time of the agglutinated water of the screw press are controlled to control the supply amount per unit time of the aggregated water supplied to the cylindrical screen machine by the agglutination reaction tank.

According to the second aspect of the present invention, the tubular screen machine control unit controls the cylindrical screen based on the content rate of the strength increasing material detected by the strength increasing material content detecting unit and the mud water concentration detected by the mud water concentration detecting unit. The rotary drive of the net machine controls the supply amount per unit time of the agglomerated mud water supplied to the tubular screen machine by the agglomerated mud water supply amount control unit. Therefore, even if the content ratio of the strength increasing material and the concentration of the muddy water are changed, the moisture content of the aggregated mud water supplied to the screw filter press can be kept constant. Therefore, the dewatered cake discharged from the screw press has a predetermined moisture content and has a certain strength.

In addition, the limit moisture content of the de-cement cake according to the content of the strength-increasing material and the specification of the screw filter is determined by a single meaning (only one interpretation), and the water content of the dewatered cake is determined according to the obtained water content. Rate, to determine the most appropriate rotational speed of the helical blade of the screw filter. Then, the screw filter control unit controls the rotational driving of the screw filter in such a manner as to rotate at the most appropriate rotation speed obtained. Therefore, the de-cemented cake discharged from the screw press has the necessary strength and is suitable for reuse.

In addition, the data to be referred to when determining the optimum rotational speed of the discharge screen machine is a plurality of types of products which are obtained by reacting a plurality of mixtures in which the concentration of the aggregating agent and the strength-increasing material are different from the concentration of the muddy water. The agglomerated mud water is actually supplied to the cylindrical screen machine, and for each concentration of the muddy water, the most appropriate rotation of the most suitable cylindrical screen machine for performing the drainage of the agglomerated mud water is obtained in advance and stored in the data storage unit. speed. Therefore, even if the content rate of the strength increasing material detected by the strength increasing material content detecting unit and the concentration of the mud water detected by the muddy water concentration detecting unit are changed, the tubular screen machine control unit can easily determine the discharge type sieve. The most appropriate rotation speed of the net machine.

Further, the agglutinated mud water supply amount control unit is based on the ratio of the draining water when the tubular screen machine is rotated at the most appropriate rotation speed and the unit of the agglutinated mud water when the screw filter press is rotated at the most appropriate rotation speed. The amount of time is processed to control the amount of supply per unit time of the agglutinated water supplied from the agglutination reaction tank to the tubular screen machine. Therefore, the processing power can be maximized.

First, a muddy water dehydration treatment system A according to an embodiment of the present invention will be described. Referring to Fig. 1, the mud water dewatering treatment system A is mainly composed of a mud water storage tank (original mud tank) 1, a mixture storage tank 2, a coagulation reaction tank 3, a hopper 4, and a screw filter 5.

Mud storage tank 1 is used to store muddy water. The muddy water system is a mixture of water, clay, silt, etc., which is left after removing gravel and most sand from the mud produced by the dam lake, the harbor, the river dredging project, and the tunnel excavation. The slurry water stored in the muddy water storage tank 1 is stirred by a stirring blade that is rotationally driven by a motor (not shown) in order to prevent sedimentation. The muddy water stored in the muddy water storage tank 1 is discharged by the pump P1, and is pumped toward the mixture storage tank 2 via the line 11. The pump P1 is driven and controlled by the control unit 12.

The muddy water storage tank 1 is provided with a muddy water concentration detecting unit 13 for detecting the concentration α of the muddy water in the muddy water storage tank 1. The muddy water concentration detecting unit 13 first measures the specific gravity of the muddy water in the slurry storage tank 1, and detects the concentration of the muddy water based on the specific gravity measurement value and the correlation between the specific gravity of the muddy water and the concentration α measured in advance. .

The mixture storage tank 2 is used to store a mixture of muddy water and sand. The muddy water is discharged by the slurry storage tank 1 by the pump P1, and is supplied into the mixture storage tank 2 via the line 11. The sand is added for the purpose of increasing the dewatering rate of the muddy water and increasing the strength of the dewatered cake, and is supplied into the mixture storage tank 2 via a conveyor belt or the like from a sanding field (not shown). The mixture stored in the mixture storage tank 2 is stirred by a stirring blade that is rotationally driven by a motor (not shown) in order to prevent sedimentation. The mixture stored in the mixture storage tank 2 is discharged by the pump P2, and is pressure-fed to the agglutination reaction tank 3 via the line 21. The pump P2 is subjected to drive control by a control unit (aggregate mud supply control unit) 22.

The mixture storage tank 2 is provided with a sand content detecting unit 23 for detecting the sand content A in the dry matter (solid matter other than water in the muddy water) in the mixture storage tank 2. The sand content detecting unit 23 measures the specific gravity of the mixture in the mixture storage tank 2, and the specific gravity measured value and the muddy water concentration α value detected by the muddy water concentration detecting unit 13 are based on the specific gravity of the mixture which is measured in advance. The correlation with the sand content A is used to detect the sand content A in the dry matter in the mixture storage tank 2.

The detailed structure of the agglutination reaction tank 3 is a biaxial type vane type agitator, and the rotating shaft in which the stirring blade is formed is rotationally driven by a motor (not shown), thereby stirring and staying inside. Retentate, and the retentate is transferred from the upstream side to the downstream side. Further, it is also possible to provide a rotating shaft in which the feeding blade is formed in the agglutination reaction tank 3, and the rotating shaft is rotationally driven by a motor to transfer the retentate.

The mixture discharged from the mixture storage tank 2 is supplied from the feed port 31 into the agglutination reaction tank 3. The mixture supplied to the agglutination reaction tank 3 is stirred by the stirring blade as a retentate, and is transferred to the downstream side by the feeding blade in response to the necessity thereof, and is supplied to the inlet 32. The aggregating agents such as an anion or a cation are mixed and reacted, whereby the soil particles are aggregated to form a floc, which in turn becomes agglomerated muddy water.

The side wall on the downstream side of the agitation reaction tank 3 in which the stirring blade and the feeding blade rotate as necessary constitutes the bank 33, and the agglomerated mud water overflowing over the bank 33 flows into the hopper 4 via the discharge port 34.

The hopper 4 is equipped with a cylindrical screen machine 41 that rotates. The tubular screen machine 41 is formed with a plurality of mesh screens for draining the mesh, and is driven to rotate by the motor M1. The motor M1 is controlled by a control unit (cylinder type screen control unit) 42 to be rotationally driven. The upper portion of the tubular screen machine 41 is exposed through the opening.

The agglomerated mud water that has fallen onto the surface of the outer cylinder of the rotary screen machine 41 that is being rotated is transported toward the downstream side as the tubular screen machine 41 rotates. At this time, a part of the moisture in the agglomerated muddy water will be The filtrate is sent to a filtrate processing tank (not shown) through the mesh of the tubular screen machine 41. On the other hand, the agglomerated mud water that has passed through the tubular screen machine 41 is supplied to the screw press 5 . Further, a water sprinkling device (not shown) for performing water spray cleaning on the tubular screen machine 41 is also provided, and this water is similarly discharged to the filtrate processing tank.

In the agglutination reaction tank 3, a plurality of mixtures having different sand content A and mud water concentration α are reacted with the agglutination agent to be produced to generate a plurality of aggregated muddy water, and the plurality of aggregated muddy waters are used in the tubular screen machine 41. It represents the time of draining to: data Drain ratio S when the cylindrical mesh unit 41 of the most appropriate rotational speed N _D 41 of the cylindrical screen and a drive unit to the optimum rotational speed N _D to rotate in the data store The storage unit 43. These materials are obtained by performing experiments or the like using the tubular screen machine 41.

In addition, the drain ratio S is the amount of data obtained when the tubular screen machine 41 supplies the aggregated mud water in the vicinity of the maximum processing capacity, in other words, the amount of the drain ratio is S for the tubular screen machine 41. Information obtained when agglutinating muddy water. The optimum rotational speed N _D and the drain ratio S of the tubular screen machine 41 depend on the specifications of the cylindrical screen machine 41, that is, the diameter, the width, the size of the mesh, the circumferential length of the drain portion, and the like. It belongs to the information inherent in the tubular screen machine 41 itself.

In the case of agglomerated muddy water having the same muddy water concentration α and the same supply amount per unit time, in the case of draining by the tubular screen machine 41, reference is made to Fig. 2, if the cylindrical screen machine 41 When the rotational speed N _D is low, the subsequent agglomerated mud water falls on the agglomerated mud water present on the outer cylinder surface of the tubular screen machine 41, so that the drain ratio S is low. On the other hand, if the rotational speed N _D of the cylindrical screen machine 41 is high, the time during which the aggregated mud water exists on the outer cylinder surface of the cylindrical screen machine 41 is short, so the drain ratio S is also very low. Therefore, there is a field of the rotational speed N _D of the cylindrical screen machine 41 having a good drain ratio S. The field of the rotational speed N _D of this drain ratio S can be regarded as the most appropriate rotational speed N _D .

If the muddy water is at a high concentration, referring to the curve indicated by the solid line in Fig. 2, the drain ratio S is relatively deteriorated, and the field D1 of the rotational speed N _D of the tubular screen machine 41 having a good drain ratio S is also very high. narrow. On the other hand, if the muddy water has a low concentration, it is a curve indicated by a broken line in Fig. 2, the drain ratio S is relatively high, and the rotational speed N _D of the tubular screen machine 41 having a good drain ratio S is good. Field D2 is also relatively broad. Further, if the energy efficiency required to drive the tubular screen machine 41 is also taken into consideration, the most appropriate rotational speed N _{D of the} cylindrical screen machine 41 is: in the field D1 or D2 of the good rotational speed N _D of the drain ratio S The lowest rotational speed within. Further, the higher the content of the sand, the better the drainage ratio S is.

The screw filter 5 includes a cylindrical filter cartridge 51 formed of a perforated metal plate or the like and having a long axis in the horizontal direction, and a rotatable spiral blade 52 disposed in the filter cartridge 51. The agglomerated mud water supplied into the filter cartridge 51 is conveyed to the downstream side (the left side in FIG. 1) by the spiral blade 52, and is subjected to press dehydration, and the separated water is dropped from the gap of the filter cartridge 51.

A feed port 53 is formed in the filter cartridge 51, and the agglomerated mud water supplied from the hopper 4 is introduced into the filter cartridge 51 from the feed port 53. The spiral blade 52 is composed of a spiral-shaped spiral blade shaft that gradually increases in diameter from the upstream side of the filter cartridge 51 toward the downstream side, and a spiral spiral blade plate that is fixed to the outer circumferential surface of the spiral blade shaft. The spiral blade 52 is rotationally driven by the motor M2. The rotational driving of the motor M2 is controlled by a control unit (screw filter control unit) 54.

When the spiral blade 52 is rotated, the aggregated mud water received from the feed port 53 is transported from the upstream side of the filter cartridge 51 toward the downstream side due to the feeding action by the spiral blade plate. Since the space between the filter cartridge 51 and the spiral blade shaft gradually narrows toward the downstream side, the aggregated muddy water is conveyed while being conveyed toward the downstream side of the filter cartridge 51. The moisture of the agglomerated mud water is squeezed through the filter cartridge 51, and the filtrate is dropped, and is discharged to the filtrate processing tank through the water collecting groove 55 formed at the bottom. Further, although not shown, a sprinkler which can eject water to clean the outer surface of the filter cartridge 51 is provided, and this water is similarly discharged to the filtrate processing tank. A discharge port 56 is provided at a downstream end portion of the filter cartridge 51. The agglomerated mud water after being dehydrated, that is, the dewatered cake C, is discharged from the discharge port 56 to the outside.

Hereinafter, a method of dehydrating a slurry water according to an embodiment of the present invention using a muddy water dehydration treatment system A will be described with reference to FIG.

First, the supply amount X per unit time of the agglomerated mud water sent to the screw press 5 is determined first (step S10). The supply amount X per unit time is changed in accordance with the rotation speed of the spiral blade 52 of the screw filter 5, and here, first, the strength of the dewatered cake C is determined (step S11). The de-cement cake C system can be used as a foundation for embankment and backfilling for reuse. The strength of the dewatered cake C is evaluated in accordance with, for example, the conical penetration test index set forth in Japanese Industrial Standard JIS A1228. If the cone penetration test index is 800 kN/m ² or more, if it is classified as the second type of construction occurrence soil and 400 kN/m ² or more, it is classified as the third type of construction occurrence soil, 200 kN/m ² or more. In addition, it is classified as the fourth type of construction occurrence soil, and is separately prescribed for reusable use.

The strength of the dewatered cake C depends on its moisture content and sand content A. Further, based on the sand content A and the specifications of the screw filter 5 to be used, the boundary moisture content which cannot be further dehydrated is determined. This is because, in such muddy water having a high water content, the rate of dewatering by the natural filtration generated by the gravity of the filter cartridge 51 of the screw filter 5 is large, and the dehydration performed by the press is only Concentration is performed in a short section near the exit of the screw press 5 whose sectional area becomes smaller, and therefore, even if the rotational speed of the spiral blade 52 of the screw filter 5 is changed, it is converted from natural filtering to The dehydration rate at the time of pressing is independent of the concentration α of the muddy water, and is substantially constant. Therefore, the moisture content of the dewatered cake C becomes a substantially constant value close to the limit moisture content as long as the rotation speed of the spiral blade 52 is within a predetermined range, regardless of whether it is high or low.

Therefore, depending on the concentration α of the supplied muddy water, the moisture content of the dewatered cake C is determined depending on the sand content A and the specifications of the screw filter 5 to be used. When the necessary strength of the cement cake C is removed, the sand content A1 in the dry matter of the muddy water matching the required strength can be determined (step S12). That is, the desiccant is subjected to the dewatering to the limit moisture content by using the screw presser 4 at various sand contents A, and the strength of the dewatered cake C at this time is determined to meet the required strength of the sand content A, as required. The strength matches the sand content A1 in the dry matter of the muddy water.

Then, the sand content A stored in the mixture stored in the mixture storage tank 2 is adjusted so that the sand content A detected by the sand content detecting unit 23 becomes the determined sand content A1. Specifically, when the sand content A is lower than the sand content A1, sand is supplied into the mixture storage tank 2 via a conveyor belt or the like from a sanding field (not shown). When the sand content A is higher than the sand content A1, the pump P1 is driven to supply mud water from the mud storage tank 1 into the mixture storage tank 2.

According to the determined sand content A1 and the specifications of the screw filter 5 (that is, the diameter, the total length of the spiral blade 52, the blade plate pitch, the opening width of the discharge port 56, and the mesh size of the filter cartridge 51), The most appropriate rotational speed N _S of the helical blade 52 is determined (step S13). For example, if the treatment amount of the agglomerated mud water in the screw filter 5 is taken as a priority, the optimum rotation speed N _{S of the} spiral blade 52 is the fastest rotation speed at which the necessary strength of the dewatered cake C can be obtained, In other words, the fastest rotational speed of the boundary moisture content can be reached. By determining the optimum rotational speed N _S of the helical blade 52 first, the supply amount X per unit time of the aggregated mud water to the screw filter 5 can be determined (step S10).

Next, the supply amount Y per unit time of the aggregated mud water of the hopper 4 is determined (step S20). The agglutinated mud water supplied to the hopper 4 is subjected to the draining operation by the tubular screen machine 41, so that the supply amount Y per unit time is increased by the cylindrical screen machine 41 in the supply amount X per unit time. The amount of the drain ratio S.

The muddy water concentration detecting unit 13 detects the concentration α of the muddy water (step S21). From the sand content A1 determined in step S12 and the muddy water concentration α detected in step S21, and referring to the data stored in the data storage unit 43, the most appropriate rotation speed N of the discharge type screen machine 41 is determined. _D and the drain ratio S (step S22). Thereby, the supply amount Y per unit time of the aggregated mud water of the hopper 4 can be determined (step S20).

Then, the mixture stored in the mixture storage tank 2 is supplied to the agglutination reaction tank 3 in a supply amount Y per unit time, and the control unit 22 drives and controls the pump P2, and is stored in the mixture for storage. The control unit 12 drives and controls the pump P1 in such a manner that the mixture in the tank 2 becomes a predetermined amount. Further, the tubular screen machine 41 is rotated at the optimum rotational speed N _D , and the control unit 42 drives and controls the rotation of the motor M1 so that the spiral blade 52 is at the most appropriate rotational speed N _{S .} The rotation of the motor M2 is controlled by the control unit 54 in such a manner as to rotate.

As described above, the cylindrical screen machine 41 rotates at the most appropriate rotational speed N _D and is supplied to the tubular screen machine 41 in response to the concentration α of the muddy water detected by the muddy water concentration detecting unit 13. The supply amount per unit time of the agglutinated mud water is controlled, so that the moisture content of the aggregated mud water supplied to the screw press 5 can be kept constant regardless of whether or not the concentration α of the muddy water is changed. Therefore, the dewatered cake C discharged from the screw press 5 has a predetermined moisture content and retains a certain strength, and has excellent recyclability.

Further, since the sand content A1 in the mixture is determined according to the necessary strength of the cement cake C, the spiral blade 52 is determined by the most appropriate rotation speed N _S determined based on the determined sand content A1. Rotate. Therefore, the dewatered cake C discharged from the screw press 5 has the necessary strength and can be suitably reused. Further, the data stored in the data storage unit 43 corresponds to a plurality of composite materials having different sand content A1 and muddy water concentration α, so that the sand content A is caused even if the necessary strength of the cement cake C is changed. Alternatively, it is possible to determine the most appropriate rotational speed N _{D of the} discharge screen machine 41.

Further, the control unit 22 controls the slave agglutination based on the drain ratio S when the tubular screen machine 41 rotates at the most appropriate rotational speed N _D and the processing capacity per unit time of the aggregated mud in the screw filter 5 . Since the amount of supply per unit time of the agglutinated water supplied to the cylindrical screen machine 41 by the reaction tank 3 is increased, the processing capability can be maximized.

In addition, although the case where the horizontal type screw press 5 is used is described as an example of the dewatering treatment system A for mud water, a vertical screw filter or the like may be used, and the components of the system may be appropriately changed. , the order of assignment, etc.

Further, each of the control units 12, 22, 42, 54 may be controlled automatically or by a worker using a switch or the like. Further, the data storage unit 43 may be a method of storing data in a memory of a personal computer or the like, or may be a method of writing a document, a chart, or the like into a written form.

Further, the sand system is added as a strength increasing material for increasing the strength of the dewatered cake C, but the present invention is not limited thereto, and may be selected from materials such as fly ash, slag, cement, and the like. One or a combination of these materials and sand.

Further, depending on the type of the strength-increasing material, not all materials have the effect of promoting drainage as sand, and of course, the most suitable rotational speed N _{D of the} tubular screen machine 41 and the screw filter 5 The boundary moisture content is changed depending on the type of strength increase material and the content rate.

A. . . Slurry dewatering system

C. . . De-cement cake

P1, P2. . . Pump

M1, M2. . . motor

1. . . Mud water storage tank (original mud tank)

2. . . Mixture storage tank

3. . . Agglutination reaction tank

4. . . hopper

5. . . Screw filter press

11, 21. . . Pipeline

12, 22, 42, 54. . . Control department

13. . . Mud water concentration detection department

twenty three. . . Sand content detection department

31. . . Inlet

32. . . Cast

33. . . Dike

34, 56. . . Discharge

41. . . Cylinder screen machine

43. . . Data storage department

51. . . Filter cartridge

52. . . Spiral blade

53. . . Inlet

55. . . Water collecting groove

Fig. 1 is an explanatory view of a muddy water dehydration treatment system according to an embodiment of the present invention.

Fig. 2 is a graph showing the relationship between the rotational speed of the tubular screen machine and the drain ratio determined by the difference in the concentration of the muddy water.

Figure 3 is a flow chart showing the dewatering treatment method of muddy water.

A. . . Slurry dewatering system

C. . . De-cement cake

P1, P2. . . Pump

M1, M2. . . motor

1. . . Mud water storage tank (original mud tank)

2. . . Mixture storage tank

3. . . Agglutination reaction tank

4. . . hopper

5. . . Screw filter press

11, 21. . . Pipeline

12, 22, 42, 54. . . Control department

13. . . Mud water concentration detection department

twenty three. . . Sand content detection department

31. . . Inlet

32. . . Cast

33. . . Dike

34, 56. . . Discharge

41. . . Cylinder screen machine

43. . . Data storage department

51. . . Filter cartridge

52. . . Spiral blade

53. . . Inlet

55. . . Water collecting groove

Claims (3)

A method for dehydrating muddy water is a mixture obtained by adding a strength-increasing material of a dewatered cake formed by muddy water, and a coagulating agent is reacted with the mixture in a coagulation reaction tank to generate agglomerated muddy water, and the agglomerated mud water is utilized. After the rotary tubular screen machine is drained, the water is depressurized by a screw press to produce a dewatering treatment method for the dewatered cake having a predetermined moisture content, which is characterized in that the content of the material is increased according to the strength The optimum moisture velocity of the spiral blade of the screw filter is determined by the boundary water content of the de-cement cake obtained by the specification of the screw filter, and the spiral blade is determined to be the most appropriate. The amount of treatment per unit time of the agglomerated mud water in the screw press when the rotation speed is rotated, and the agglutinated water of the treatment amount per unit time is supplied to the screw filter to make the aggregating agent a plurality of kinds of mixtures formed by reacting with a plurality of mixtures of the strength increasing material and the muddy water concentration The agglutinated mud water is supplied to the cylindrical screen machine, and for each concentration of the muddy water, the most appropriate rotation speed of the cylindrical screen machine which is the most suitable for draining the aggregated mud water is obtained in advance as data. Controlling the rotational driving of the spiral blade of the screw filter by rotating the spiral blade of the screw filter at the most appropriate rotation speed, and referring to the above-mentioned data to determine the strength increasing material The optimum rotation speed of the above-described cylindrical screen machine having the content rate and the concentration of the muddy water, and then rotating at the most appropriate rotation speed determined To control the rotational drive of the aforementioned tubular screen machine, and to make the drain ratio when the cylindrical screen machine is rotated at the most appropriate rotational speed as described above, and to make the aforementioned screw press to be the aforementioned screw press. The amount of processing per unit time of the agglomerated mud water at the time of the rotation of the spiral blade at the most appropriate rotation speed is controlled to control the supply amount per unit time of the aggregated mud water supplied to the cylindrical screen machine by the agglutination reaction tank. The method for dehydrating muddy water according to claim 1, wherein the strength increasing material comprises at least one of sand, fly ash, slag, and cement. A mud water dewatering treatment system characterized by comprising: a coagulation reaction tank, a content ratio of a strength increasing material in a mixture of a coagulant and a strength-increasing material added with a dewatered cake formed by mud water, and muddy water The plurality of mixtures having different concentrations react to form aggregated mud water; the muddy water concentration detecting unit detects the concentration of the muddy water; and the strength increasing material content detecting unit detects the content of the strength increasing material in the mixture; the cylindrical sieve The net machine rotates to drain the agglomerated mud water generated by the agglutination reaction tank; the tubular screen machine control unit controls the cylindrical screen machine according to the concentration of the mud water detected by the muddy water concentration detecting unit. Rotary drive; the agglomerated mud water supply amount control unit controls the supply amount per unit time of the aggregated mud water supplied to the cylindrical screen machine by the agglutination reaction tank; The screw filter press is configured to perform dewatering of the agglomerated mud water after the draining of the tubular screen machine to produce a dewatering cake having a predetermined moisture content; and the data storage unit stores the data stored in the data storage unit: The optimum rotation speed of the spiral blade of the screw filter is determined by the content rate of the strength-increasing material and the boundary water content of the de-cement cake obtained by the specification of the screw filter, and The optimum rotation speed is the amount of processing per unit time of the agglutinated water in the screw press when the spiral blade is rotated, and the amount of the aggregated mud per unit time is supplied to the screw press. A plurality of kinds of aggregated mud water generated by reacting a plurality of kinds of mixtures in which the concentration of the agglomerating agent and the concentration of the strength-increasing material and the concentration of the slurry are different are supplied to the cylindrical screen machine, and the concentration of each of the muddy water is obtained. The most appropriate rotation speed of the aforementioned cylindrical screen machine for performing the drainage of the agglomerated mud water; the screw filter control The control unit is configured to control the rotational driving of the screw press; the tubular screen machine control unit refers to the data stored in the data storage unit, and the strength increasing material detected by the strength increasing material content detecting unit is detected. The content rate and the concentration of the muddy water detected by the muddy water concentration detecting unit determine the optimum rotational speed of the tubular screen machine, and control the rotation at the most appropriate rotational speed determined. The rotary driving of the tubular screen machine, the agglutinated mud water supply amount control unit is based on the most appropriate The rotation speed is such that the drain ratio at the time of the rotation of the cylindrical screen machine and the processing capacity per unit time of the agglutination water in the screw filter are controlled to control the agglutination water supplied from the agglutination reaction tank to the cylindrical screen machine The amount of supply per unit of time.