JPH09294998A - Method and apparatus for reutilizing sludge as resources - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dehydrate, granulate and solidfy a large amt. of discharged sludge discharged from an excavation process of civil engineering construction, unstable in its properties and difficult to reutilize heretofore to regenerate the same as resources having stable and homogenous capacity. SOLUTION: A sludge stirring tank 2 in which sludge is charged is provided within a unit frame 1 and a screw dehydrator 3 is arranged to the lower part of the stirring tank 2 and a dehydrated cake screw conveyor 4 is provided to charge a dehydrated cake in a raw material weighing bin 5 to weigh the same and the weighed cake is charged in a mixer 6. An additive is fed by an additive screw conveyor 8 to be supplied to an additive weighing bin 9 under control and the weighed additive is charged in the mixer 6. A head guide rail is attached to the upper part of the mixer 6 arranged in a tiltable manner and a mixing head 7 is mounted thereon and a mixing shaft 74 having mixing blades provided to the lower end thereof is provided and the mixing blades are rotated by a motor fitted with a mixing blade speed reducer and these devices are housed in the unit frame 1 to be made transportable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for dehydrating, granulating and solidifying discharged sludge from an excavation method in civil engineering work, in which sludge properties are different depending on the place of origin and the properties are unstable.
The present invention relates to a recycling technology for sludge that has been difficult to reuse, which can be easily recycled according to the purpose and purpose.

[0002]

2. Description of the Related Art Conventional sludge recycling is based on physical techniques such as draining, sun-drying, load consolidation dehydration, mechanical dehydration, high-quality mixing, and chemicals using cement-based, lime-based, and polymer-based additives. The technology is used to refill roadbed materials, and only about 2% of total emissions are reused. Further, in recent years, studies have been conducted on recycling resources by changing the material to make it into a material by baking or melting sludge, or solidifying and forming it into a block or the like.

[0003]

In recent years, underground use excavation work has been increasing with the expansion of urban infrastructure development, and a large amount of highly hydrous sludge containing bentonite has been discharged from the excavation method. Most of the sludge generated in large quantities is transported to a managed final disposal site as landfill as industrial waste that is difficult to treat, and the remaining years of the managed final disposal site are shortened, and the natural environment is caused by large-scale illegal sludge dumping. Destruction is progressing and it is a big social problem. Most of the discharged sludge has unstable properties, and the properties vary depending on the depth of excavation and the location where it is generated, so it is difficult to obtain a resource with stable and homogeneous performance using only a single treatment method, making reuse difficult. There is. In the conventional method using both physical technology and chemical technology, it is generally considered that each process step is an independent process method, and each process is performed at a plurality of places and each process is performed. There is a concept that the reproduction processing is completed after the completion of the processing sequentially, and it took a very long time to recycle the resources. Therefore, most of the current sludge treatment is carried out for the purpose of landfill disposal, and the purpose is to meet the standard of landfill (waste water content 85% or less) to the management type final disposal site. In addition, recycling sludge by burning and melting consumes enormous amount of energy, but it is difficult to mass-produce products, resulting in high cost and economically difficult to commercialize. For this reason, there is an urgent need for the rapid development of a sludge recycling resource technology that makes sludge with unstable properties in a short time into a resource with stable and homogeneous performance according to the purpose of reuse. The present invention has been made to solve these problems.

[0004]

[Means for Solving the Problems] Unit frame (1)
Inside the agitator (24) at the lower end of the stirring shaft (23)
Is provided, is supported by a bearing (22), is rotated by a motor (21) with a sludge reducer, and is provided with a sludge agitation tank (2) having a discharge port (25) at the lower end of the tank. The connecting pipe (26) having the overflow discharge port (27) is connected to the lower part of the discharge port (25), and the lower end thereof is connected to the sludge input port (32a) at the upper part of the casing (32) of the screw dehydrator (3). . The sludge agitation tank (2) supplies the fed sludge having a high water content to the screw dehydrator (3) while agitating it with an agitator (24). Excessive supply of sludge is made to overflow from the overflow discharge port (27) and piped so as to return to the sludge agitation tank (2). The screw dehydrator (3) is provided with a casing (32) on a leg portion (31), and a cylindrical drainage screen is provided on an outer peripheral portion of an auger flight (34a) of an auger (34) in the casing (32). (35) is provided. A motor (33) with a dehydration reducer rotates the auger (34) in the casing (32), and a two-screw auger flight (34) fixed to the auger (34).
In a), the thrown sludge is transferred toward the dehydrated cake discharge pipe (40). A resistance plate (36) attached to the dehydrated cake discharge pipe (40) attached to the end of the casing (32) so as to be swingable with one end as a fulcrum closes the opening of the dehydrated cake discharge pipe (40). It is arranged as follows. As a closing force of the resistance plate (36), the weight bar (3
The load of the weight (39) is transmitted via 7) and the link (38). The rotation of the auger (34) causes the sludge to be pressure-fed while pushing the resistance plate (36) open against the closing resistance of the resistance plate (36). Moisture content of the sludge is squeezed out by pressure feed, filtered by the screen (35), the moisture is discharged from the drainage discharge port (30) of the casing (32), and the sludge solid matters are dehydrated cake as a dehydrated cake discharge pipe (40). ) And discharged into the dehydration cake screw conveyor (4) through the dehydration cake charging port (42). The dehydrated cake is vertically conveyed by the dehydrated cake screw conveyor (4) by the rotation of the dehydrated cake speed reducer motor (41), and the dehydrated cake is fed from the conveyor discharge pipe (43) to the raw material measuring bottle (5) as a raw material for recycling. Discharge. The raw material metering bottle (5) is provided with a raw material gate cylinder (51) and a raw material gate (52), and the raw material is fed to the mixer (6) through the auxiliary chute (53) while measuring the weight of the raw material charged by batch processing. To supply. The mixer (6) in the shape of a cylindrical container supports the fulcrum pins (61) provided on both side surfaces with the fulcrum legs (62) of the mixer, and the mixer inclined cylinder (6)
6) Allow to tilt at any angle. The mixer bottom plate is provided with a mixer discharge port (63), and the discharge door (6
4) fitted so that it can be closed or opened with the outlet door cylinder (65). The head guide rail (78) is mounted on the upper part of the mixer (6), the mixing head (7) is mounted on the head guide rail (78), and the motor (7) with a head moving speed reducer is mounted.
The rotation of 7) allows the mixing head (7) to move along the head guide rail (78) via the head moving screw (76). A cylindrical sleeve (75) is mounted on the mixing head (7) along with a head guide rail (78) so as to be vertically movable. Sleeve (75)
A rack is cut on the outer surface in the vertical direction of the mixing shaft, and a mixing shaft elevating binion (79) is disposed so as to be meshed with each other, and a sleeve (75) can be moved up and down by rotating the mixing shaft elevating binion (79). The mixing shaft (74) is rotatably mounted in the cylindrical sleeve (75) so as to be held in a fixed position so that the mixing shaft (74) is moved up and down together with the sleeve (75). It A spline portion (74a) is processed and provided on the shaft upper portion of the mixing shaft (74), and a driven gear (73) having a spline hole is meshedly attached to this spline portion. The rotation of the motor (71) with a mixing blade reducer is transmitted to the driven gear (73) by the drive gear (72) attached to the shaft end, and the mixing shaft (7) is transmitted through the spline portion.
4) Rotate. A plurality of mixing blades (70) are attached to the lower end of the mixing shaft (74) in the direction of the axis. Multiple mixing wings (70)
Are different angles θ1. θ2. θ3. . . . Bend with and attach. An additive screw conveyor (8) for supplying the additive to an additive measuring bottle (9) is provided. Addition of additives is performed in conjunction with batch processing of the raw material measuring bottle (5).
The additive amount is controlled by the control panel (11) so as to be automatically set in advance in proportion to the amount of the raw material charged into the raw material measuring bottle (5) by an arbitrary proportional value. The additive to be introduced into the additive conveyer charging port (82) is conveyed upward by the rotation of the motor (81) with an additive speed reducer, and is discharged from the additive conveyer discharge pipe (83) until a proportional charging amount is reached. Feed to additive metering bottle (9). The motor with additive speed reducer (81) is automatically stopped when a predetermined proportional input amount is reached. The additive metering bottle (9) measures a predetermined proportional amount and operates the additive gate cylinder (91),
The additive gate (92) is opened and the additive is loaded into the mixer (6). The mixer (6) stirs and kneads the raw material and the additive by rotating the mixing blade (70) to obtain a predetermined effect of adding the additive, and opens the outlet door (64) to open the product chute (6).
Discharge to 7). The apron steep slope conveyor (10)
The raw material supply bottle (5) is installed for the purpose of making the supply state of raw material into a sub-column and facilitating production adjustment. A control panel (11) is provided to enable automatic control of a series of processing steps.
Be able to control manually. Each of these mechanical devices is housed and installed in the unit frame (1) so that it can be moved and installed as a unit. The present invention is a sludge recycling method and a recycling apparatus thereof having the above-mentioned configurations.

[0005]

When the present invention is used, sludge having a high water content is put into the sludge stirring tank (2) and supplied to the screw dehydrator (3) while being stirred by the agitator (24) to supply the auger (34). By rotating, the sludge is pushed out against the resistance of the resistance plate (36) and pressure-fed, whereby the sludge is compressed, squeezed, and the water content of the sludge is separated and dehydrated. The separated water is filtered through a screen (35) arranged in the casing (32),
Drain through the drainage outlet (30). The dehydration rate can be set by adjusting the weight of the resistance applied to the resistance plate (36) with the weight (39). Therefore, the weight is adjusted according to the purpose of recycling, and the proper dehydration rate is set. be able to. Sludge is dehydrated by a screw dehydrator (3),
Dehydrated cake-shaped, dehydration screw conveyor (4)
It is put into a raw material measuring bottle (5) as a raw material for recycling. The raw material is put into and discharged from the raw material measuring bottle (5) by batch operation for each set amount.
The supply of recycled raw materials by the apron steep slope conveyor is controlled in the same manner. For the additive, the mixing ratio with the raw material is set in the control unit in advance, and the additive amount is controlled and supplied so that the predetermined addition amount is obtained while the addition amount is measured by the additive measuring bottle (9). In conjunction with the operation, the mixer (6) is charged and supplied at an arbitrary timing. Since the mixing shaft (74) can be arbitrarily controlled and moved in the diametrical direction and the vertical direction within the mixer (6), the rotating shaft outside the mixing blade (70) attached to the lower end of the shaft and the cylindrical side wall of the mixer (6). The inner space can be set freely, and at the same time, the lower surface of the mixing blade (70) and the mixer (6)
You can freely set the distance from the bottom plate top surface. Further, the rotation speed of the motor (71) with a mixing blade reducer can be controlled at a variable speed, and the rotation speed of the mixing blade (70) is controlled to a rotation speed according to the purpose of recycling. Since a plurality of mixing blades (70) are attached and bent at different angles in the rotation direction, the raw materials and additives are agitated in various directions due to the angle of the mixing blades when rotating in the mixer. It can be kneaded. When the mixer (6) is tilted and stirred and kneaded by the rotation of the mixing blade, the raw materials and the additives that are splashed out of the blade are collected and mixed in the lower part of the mixer. When sludge that has been dehydrated to reduce the water content is used as a raw material, and a solidifying agent is used as an additive, and the mixture is agitated and kneaded with a mixing blade (70) at high speed, the sludge particles and residual water are further separated by centrifugal force, resulting in a large number of fine sludge particles. The particles combine with the solidifying agent to increase the particle size and granulate and solidify. It is possible to granulate fine particles of 74 μ or less, which were difficult to use, and solidify and grow them to particles usable as a resource of 75 μ or more. Since the inclination angle of the mixer (6) and the position and rotation speed of the mixing blade (70) can be freely set, it is possible to set appropriate conditions according to the unstable properties of sludge and to meet the purpose of recycling. It can be recycled by granulation. The raw materials are put into the mixer (6) in advance, the mixture is agitated at a high speed by the mixing blade (70), the sludge particles and the residual water are further separated by centrifugal force, and then the additive is added and mixed as a superabsorbent polymer. It is possible to efficiently reduce the apparent water content drastically by absorbing water with a super absorbent polymer, and by adding and adding a solidifying agent, it can be granulated and solidified in an extremely short time to recycle the high water content sludge. can do. By using pigments and solidifying agents as additives,
It can be recycled as a high-value-added product with various colors, and can be used, for example, as bunker sand in golf courses or colorful sand in parks. In addition, various additives such as antibacterial agents and herbicides can be added to the additives, and new applications as recycling can be developed.

[0006]

Embodiments of the present invention will be described below. A sludge stirring tank (2) is provided in the unit frame (1), and a stirring shaft (23) provided with an agitator (24) at the lower end is rotated by a motor (21) with a sludge reducer so that the bearing ( 22). An outlet (25) is provided at the lower end of the sludge agitation tank. Overflow outlet (2
The connecting pipe (26) having 7) is connected to the lower part of the discharge port (25), and the lower end thereof is connected to the sludge input port (32a) at the upper part of the casing (32) of the screw dehydrator (3). The sludge agitation tank (2) supplies the high water content sludge that has been input to the screw dehydrator (3) while agitating it with an agitator (24). Excessive supply of sludge is made to overflow from the overflow discharge port (27) and piped so as to return to the sludge agitation tank (2). The screw dehydrator (3) has a casing (32) on the leg (31).
And a cylindrical screen (35) for drainage is arranged on the outer periphery of the auger flight (34a) of the auger (34) in the casing (32). An auger (34) in the casing (32) with a motor (33) with a dehydration reducer
Is rotated, and the sludge introduced is transferred toward the dehydrated cake discharge pipe (40) by a two-screw auger flight (34a) fixed to the auger (34). A resistance plate (36) attached to the dehydrated cake discharge pipe (40) attached to the end of the casing (32) so as to be swingable with one end as a fulcrum closes the opening of the dehydrated cake discharge pipe (40). It is arranged as follows. The weight bar (37) and the link (38) are used as the closing force of the resistance plate (36).
The load of the weight (39) is transmitted via the. The rotation of the auger (34) causes the sludge to be pressure-fed while pushing the resistance plate (36) open against the closing resistance of the resistance plate (36). Moisture content of the sludge is squeezed out by pressure feeding, filtered by the screen (35), and the moisture is contained in the casing (32).
The sludge solids are discharged from the drainage discharge port (30) of the above, and the sludge solid matter is discharged from the dehydration cake discharge pipe (40) as a dehydrated cake,
The dehydrated cake is introduced into the dehydrated cake charging port (42) of the screw conveyor (4). The dehydrated cake is vertically conveyed by the dehydrated cake screw conveyor (4) by the rotation of the dehydrated cake speed reducer motor (41), and the dehydrated cake is fed from the conveyor discharge pipe (43) to the raw material measuring bottle (5) as a raw material for recycling. Discharge. The raw material metering bottle (5) is provided with a raw material gate cylinder (51) and a raw material gate (52), and while measuring the input weight of the raw material by batch processing,
The raw material is supplied to the mixer (6) through the auxiliary chute (53). The cylindrical container-shaped mixer (6) supports the fulcrum pins (61) provided on both side surfaces with the mixer fulcrum legs (62), and the mixer tilt cylinder (66) provides 0 ° to 65 °.
Be able to incline at an angle of ° and set the angle according to the purpose of recycling. A mixer outlet (63) is provided in the mixer bottom plate portion, and an outlet door (64) is attached so that it can be closed or opened by an outlet door cylinder (65). The head guide rail (78) is mounted on the upper part of the mixer (6), the mixing head (7) is mounted on the head guide rail (78), and the head moving screw (76) is rotated by the rotation of the motor (77) with a head moving speed reducer. Through which the mixing head (7) can be moved along the head guide rail (78). A cylindrical sleeve (75) is mounted on the mixing head (7) along with a head guide rail (78) so as to be vertically movable. A rack is cut on the outer surface in the vertical direction of the sleeve (75), and a mixing shaft raising and lowering binion (79) is arranged so as to be meshed with each other so that the sleeve (75) can be moved up and down by rotation of the mixing shaft raising and lowering binion (79). To The sleeve (75) is mounted by rotatably mounting the mixing shaft (74) in a cylindrical sleeve (75) so as to hold it in a fixed position.
The mixing shaft (74) is moved up and down together with the up and down movement. A spline portion (74a) is processed and provided on the shaft upper portion of the mixing shaft (74), and a driven gear (73) having a spline hole is meshedly attached to this spline portion. The rotation of the motor (71) with a mixing blade reducer is transmitted to the driven gear (73) by the drive gear (72) attached to the shaft end, and the mixing shaft (74) is rotated via the spline portion. The rotation speed of the mixing shaft (74) by the motor (71) with a mixing blade reducer is controlled by an inverter so that it can be set in the range of 20 rpm to 1500 rpm. Three mixing blades (70) are attached to the lower end of the mixing shaft (74) in the direction of the axis. The three mixing blades (70) have different angles θ1 = 15 °. θ2 = 30 °. θ3 = 4
Bend at 5 ° and attach. An additive screw conveyor (8) for supplying the additive to an additive measuring bottle (9) is provided. Addition of additives is performed in conjunction with batch processing of the raw material measuring bottle (5). The additive amount is controlled by the control panel (11) so as to be automatically set in advance in proportion to the amount of the raw material charged into the raw material measuring bottle (5) by an arbitrary proportional value. The additive to be introduced into the additive conveyer charging port (82) is conveyed upward by the rotation of the motor (81) with an additive speed reducer, and is discharged from the additive conveyer discharge pipe (83) until a proportional charging amount is reached. Feed to additive metering bottle (9). The motor with additive speed reducer (81) is automatically stopped when a predetermined proportional input amount is reached. The additive metering bottle (9) measures a predetermined proportional input amount, operates the additive gate cylinder (91), releases the additive gate (92), and inputs the additive into the mixer (6). . The mixer (6) stirs and kneads the raw material and the additive by rotating the mixing blade (70),
After the predetermined additive effect is obtained, the discharge port door (64) is opened and the product chute (67) is discharged. The apron steep slope conveyor (10) is installed for the purpose of making the supply state of the raw material to the raw material measuring bottle (5) into a sub-column and facilitating production adjustment. A control panel (11) is provided to enable automatic control of a series of processing steps and manual control. Unit frame (1) for each of these mechanical devices
It is housed and installed inside, and can be moved and installed as a unit.

[0007]

EFFECTS OF THE INVENTION By using the present invention, the location of sludge varies depending on the construction and the excavation method varies depending on the construction site. High sludge with high water content can be granulated and solidified and recycled as a resource with stable and uniform performance. At the excavation work site, excavated sludge that had been disposed of until now can be treated on-site, recycled, and used for backfilling, which shortens the construction work and saves material, resulting in cost reduction. The recycling rate of sludge, which is industrial waste, can be significantly improved. By reducing the amount of sludge waste, it is possible to extend the remaining years of the managed final disposal site, which is difficult to newly install, and
It can contribute to the suppression of the destruction of the natural environment due to large-scale illegal dumping of sludge. By adding a pigment as an additive,
Sludge can be recycled into sand of various colors and high value-added products can be created. By blending and using various additives, it becomes possible to recycle them as resources for various purposes.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing an outline of the present invention.

FIG. 2 is a plan view showing the outline of the present invention.

FIG. 3 is an enlarged cross-sectional view of essential parts showing a sludge stirring tank and a screw dehydrator.

FIG. 4 is an enlarged cross-sectional view of a main part taken along the line AA of FIG.

5 is a magnified sectional view of an essential part taken along the line BB in FIG. 1, showing a mixing blade and a mixer bottom plate.

[Explanation of symbols]

1 Unit Frame 2 Sludge Stirring Tank 3 Screw Dewatering Machine 4 Dewatering Cake Screw Conveyor 5 Raw Material Measuring Bin 6 Mixer 7 Mixing Head 8 Additive Screw Conveyor 9 Additive Measuring Bin 10 Apron Steep Conveyor 11 Control Panel 21 Motor with Sludge Reducer 22 Bearing 23 Stirring Shaft 24 Agitator 25 Discharge Port 26 Connection Pipe 27 Overflow Discharge Port 30 Drainage Water Discharge Port 31 Leg 32 Casing 32a Sludge Inlet 33 Motor with Dewatering Reduction Gear 34 Auger 34a Auger Flight 35 Screen 36 Resistor Plate 37 Weight Bar 38 link 39 weight 40 dehydrated cake discharge pipe 41 motor with dehydrated cake speed reducer 42 dehydrated cake input port 43 conveyor discharge pipe 51 raw material gate cylinder 52 raw material gate 53 auxiliary chute 61 fulcrum 62 Mixer fulcrum leg 63 Mixer discharge port 64 Discharge port door 65 Discharge port cylinder 66 Mixer tilt cylinder 67 Product chute 70 Mixing blade 71 Mixing blade reducer motor 72 Drive gear 73 Driven gear 74 Mixing shaft 74a Mixing shaft 74a Spline part 75 Sleeve 76 Head moving screw 77 Head moving speed reducer motor 78 Head guide rail 79 Mixing shaft raising / lowering binion 81 Additive speed reducer motor 82 Additive conveyor inlet 83 Additive conveyor discharge pipe 91 Additive gate cylinder 92 Additive gate

Claims (5)

[Claims] 1. A sludge agitation tank for introducing sludge is provided in a unit frame, a screw dehydrator is installed below the sludge agitator, and a dehydration cake screw conveyor is provided to vertically convey the dehydrated sludge to a raw material measuring bottle. Charged as a raw material, weighed, charged into a mixer, convey the additive on the additive screw conveyor, supply control to the additive measuring bottle so as to have a preset additive compounding ratio to the raw material,
Put the additive into the mixer, and in the mixer installed so that it can be tilted, arrange a mixing blade that rotates at any rotation speed at any position, knead the raw sludge and the additive, and remove sludge particles. , A method for recycling sludge, which comprises granulating and solidifying into usable particles and recycling. 2. A sludge agitation tank for introducing sludge is provided in a unit frame, a screw dehydrator is installed below the sludge agitator, and a dehydration cake screw conveyor is provided to vertically convey the dehydrated sludge to a raw material measuring bottle. Throw in, weigh,
Add to the mixer, convey the additive on the additive screw conveyor, control the supply to the additive metering bin so that the additive compounding ratio is preset to the raw material, add the additive to the mixer, and tilt it. Install the head guide rail on the installed mixer, install the mixing head, and install the mixing sleeve with a cylindrical sleeve that holds the mixing shaft in a fixed position and has the mixing blade at the lower end. Through the sleeve to allow the motor with a mixing vane reducer to rotate the mixing vanes, and then house these devices in the unit frame to knead the raw sludge and additives to make the sludge particles available. A sludge recycling device characterized by granulating and solidifying into particles and recycling. 3. A head guide rail is mounted on a mixer, the mixing head is mounted, and a head moving screw is rotated by a motor with a head moving speed reducer so that the mixing head can be moved along the head guiding rail. The rack is cut on the outer surface of the sleeve attached to the head, and the mixing shaft is raised and lowered by the meshing rotation of the mixing shaft raising and lowering binion to raise and lower the mixing shaft. 3. The sludge recycling apparatus according to claim 2, wherein the position of the mixing blade can be freely set so that the rotation of the motor with the mixing blade reducer is transmitted to the mixing shaft via the driven gear to rotate the mixing blade. 4. A raw material is put into a mixer in advance and stirred with a mixing blade to separate sludge particles and residual water by centrifugal force, and then the additive is mixed as a superabsorbent polymer to obtain a superabsorbent polymer. The sludge recycling apparatus according to claim 2, wherein the apparent water content is decreased by water absorption of the polymer, and a solidifying agent is further added and charged to granulate and solidify to recycle the high water content sludge. 5. The sludge recycling apparatus according to claim 2, wherein a pigment and a solidifying agent are used as additives to impart various colors and granulate and solidify to recycle the high water content sludge.