JP2527524B2 - Compression dehydration method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dehydrating method and a dehydrating apparatus for compressing an object to be dehydrated containing water and solids and having low fluidity to remove water from the object to be dehydrated.

[0002]

2. Description of the Related Art A technique of compressing a substance having a low fluidity containing water and solids to separate the water is used in many industrial fields such as the food industry handling brewed dregs and a treatment plant for activated sludge. BACKGROUND ART Conventionally, a technique is known in which a substance to be dehydrated composed of a substance containing moisture and solids is sandwiched between filter cloths and pressed from the outside so that the moisture flows out through the filter fabric to separate the moisture from the substance to be dehydrated. Further, for example, as disclosed in Japanese Patent Publication No. 1-16600, a press for compressing an article to be dehydrated, which is an outer wall pressed against an inner surface of a rigid tubular support and an inner wall made of an elastic material pressed against the article to be dehydrated. There is known a press that includes an annular inflatable chamber having a toy, an object to be dehydrated is disposed inside an inner wall of the inflatable chamber, a hydraulic pressure is supplied to the inflatable chamber, and the object to be dehydrated is compressed.

[0003]

In the conventional dehydrator using a filter cloth, since the water flowing out from the material to be dehydrated passes through the filter cloth and is removed, the filter cloth has a solid content or the like in the material to be dehydrated. As a result, there is a problem that clogging may occur and water of the substance to be dehydrated may not be sufficiently separated, and that cleaning the filter cloth from clogging requires labor and time for cleaning. Further, since the filter cloth is damaged by high pressure, it may not be possible to apply a sufficiently high pressure to the substance to be dehydrated, and the moisture may not be sufficiently dehydrated. Further, since the moisture passes a long distance in the substance to be dehydrated, It takes a relatively long time to be discharged from the product, has inefficiencies, and has a drawback that a dehydrated cake having a low water content cannot be obtained.

The object of the present invention is to solve the drawbacks of the conventional dewatering device, to prevent the filter cloth from being clogged, and to use a novel compression dewatering method in which the filter cloth can be reused without regenerating the clogging of the filter cloth. And to provide a device. Another object of the present invention is to provide a dehydration method and apparatus capable of exerting a sufficiently high pressure on a substance to be dehydrated without damaging the filter cloth and sufficiently separating water from the substance to be dehydrated. .
It is another object of the present invention to provide a compression dehydration method and apparatus capable of smoothing the flow of water of the substance to be dehydrated and separating the water from the substance to be dehydrated in a short time.

[0005]

According to the dehydration method of the present invention, a step of preparing a sheet having fine irregularities through which water can flow along the sheet surface, and a large number of thin layers of the sheet and the article to be dehydrated are alternately stacked. Forming a laminate to be dehydrated, pressing the laminate to be dehydrated in a direction substantially perpendicular to the sheet surface to allow moisture to flow out from the object to be dehydrated along the sheet surface, and removing the leaked moisture Including the step of doing. Preferably, the step of forming the dehydrated product laminate comprises the step of winding a sheet and a thin layer of the dehydrated product together on a take-up reel to form a cylinder of the dehydrated product laminate. The pressing of the dehydrated product laminate is constituted by the step of applying hydraulic pressure to the outer peripheral surface of the cylindrical body. Further, the step of applying hydraulic pressure to the outer peripheral surface of the cylindrical body includes the steps of arranging a stretchable film body so as to be in contact with the outer peripheral surface of the cylinder body, arranging a pressure container surrounding the film body, and the film body and the pressure container. And a step of supplying a pressure liquid to the pressure chamber. More preferably, the step of pressing the dehydrated product laminate includes the step of controlling the pressing force so that the dehydrated product laminate is compressed in proportion to the volume of the water flowing out.

The dewatering device of the present invention comprises a sheet to be dehydrated, which is formed by alternately laminating a sheet having minute irregularities through which water can flow along the sheet surface and a plurality of thin layers to be dehydrated. It includes means for pressing and compressing in a substantially vertical direction and means for discharging water flowing out from the dehydrated product laminate to be compressed. Preferably, the dehydrated product laminate is formed by a cylindrical body in which a sheet and a thin layer of the dehydrated product are wound together and a plurality of thin layers of the sheet and the dehydrated product are alternately laminated, and the dehydrated product laminate is compressed. The means for performing is constituted by means for exerting hydraulic pressure on the outer peripheral surface of the cylindrical body. The means for exerting hydraulic pressure on the outer peripheral surface of the cylindrical body is a stretchable film body arranged so as to be in contact with the outer peripheral surface of the cylindrical body, a pressure-resistant container arranged surrounding the film body, and inner surfaces of the film body and the pressure-resistant container. A pressure chamber provided between the pressure chamber and the pressure chamber, and means for supplying and discharging the pressure liquid to and from the pressure chamber. More preferably, the sheet surface is provided with naps so that the solid content of the dehydrated material can be easily separated.

The means for pressing and compressing the dehydrated laminate in a direction substantially perpendicular to the sheet surface applies a uniform pressure to a wide area of the sheet surface. The sheet may be woven fabric or non-woven fabric as long as it has a structure having irregularities in which water channels can flow between the sheet surface and the substance to be dehydrated, and it is not necessary to pass moisture. The end surface of the dehydrated product laminate is open, and the speed of pressing the dehydrated product is, for example, 6 kg / cm per minute.
Set it to ² or less and adjust to the outflow amount of water so that the substance to be dehydrated does not overflow. Moisture receives a large flow resistance in the substance to be dehydrated and it takes time to flow out, so
If the layer to be dehydrated in the dehydrated product laminate has a large thickness,
This is inconvenient because it requires a long time to maintain the relationship of compressing in accordance with the outflow amount of water. Therefore, the thickness of the layer to be dehydrated needs to be changed depending on the property of the substance to be dehydrated, and is, for example, 15 mm to 3 mm. In order to increase the throughput of the material to be dehydrated per hour, it is necessary to increase the number of layers of the material to be dehydrated, but practically 20 to 8 layers.
0 layer is suitable.

[0008]

EXAMPLE FIG. 1 is a schematic sectional view of an article to be dehydrated laminate 2 according to one example of the present invention, in which each of the sheets S1, S2, S3, ... Sn, Sn + 1 is formed by an appropriate method. In between, the thin layers Q1, Q2, Q3, Qn-1, of the material to be dehydrated,
A laminated body in which n layers of the substance to be dehydrated are vertically stacked to sandwich Qn is formed, and both ends in the horizontal direction of the laminated body are opened. The number of layers to be dehydrated, that is, n is 20 to 80. The thickness of each layer of the material to be dehydrated is 15 to 3 mm.
The laminated body is compressed by the uniform pressure P in the vertical direction, and the moisture in the dehydrated material is caused to flow along the sheet surface to be removed from the end surface of the laminated body. In the pressing process of the dehydrated material, the rate of increase of the pressure P is changed to the water content W (W in FIG. 1 and FIGS.
Value), for example, 6 kg per minute
The material to be dehydrated is prevented from protruding by controlling it to be equal to or less than / cm ² .

2A to 2C schematically show the dehydration process for one of the thin layers Qm of the substance to be dehydrated in the embodiment of FIG.
2A is a cross-sectional view of a state before pressurization, FIG. 2B is a state during pressurization, and FIG. To the thin layer Qm of the material to be dehydrated between the sheets Sm and Sm + 1, the pressure P that acts uniformly on the sheet in the vertical direction is applied, and the water content W in the material to be dehydrated is indicated by arrows F and F in FIG. 2B. So that it flows out along the seat surface. The pressure P is controlled so that the volume of the substance to be dehydrated is reduced according to the amount of water flowing out, and the final pressure Pmax is, for example, 60 kg / cm ² . By applying such a pressure P, the thin layer Qm thickness of the substance to be dehydrated is reduced from the initial thickness T1 (FIG. 2A) to the final thickness T2 (FIG. 2C), and the water content of the substance to be dehydrated is increased. Separate the parts.

Since the substance to be dehydrated usually needs to be separated from the sheet S after the dehydration step, the sheet surface of the sheet S has irregularities that allow the flow of water, and also the dehydration step. It is necessary to have the property of being peelable from the material to be dehydrated after completion.

FIGS. 3A and 3B are schematic sectional views showing a dehydration process of a cylindrical body of a laminate to be dehydrated in another embodiment of the present invention. FIG. 3A is before pressurization and FIG. 3B is pressurization. It is sectional drawing which shows the back. The cylindrical body 14 formed by winding the dehydrated product laminate on the take-up reel 16 is housed in the pressure-resistant drum 10,
A cylindrical pressure chamber 12 is formed between the inner surface of the pressure-resistant drum 10 and the cylindrical body 14.

The upper half of FIG. 4 is a schematic sectional view showing a side cross section of the cylindrical body 14 of the laminate to be dehydrated before pressing, and the lower half of FIG. 4 is the side of the cylindrical body 14 after pressing. It is a schematic sectional drawing which shows a cross section. As can be seen in FIG. 4, the pressure chamber 12 is
It is formed by a stretchable film body 24 made of rubber arranged adjacent to the outer peripheral surface of the cylindrical body 14 and the inner surface of the pressure-resistant drum 10. The pressurized liquid is supplied to and discharged from the pressurized chamber 12 through the pressurized liquid inlet / outlet 32 communicating with the inside of the pressurized chamber 12. The end surface of the take-up reel 16 is covered with a pressure resistant end surface 22 having a large number of drainage holes 26.

When the pressure water is supplied to the pressurizing chamber 12 through the pressurized liquid inlet / outlet 32 after inserting the cylindrical body 14 made of the dehydrated laminate into the pressure resistant drum 10, the pressure resistant drum 10 is not deformed. The cylindrical body 14 is compressed, and the water content of the substance to be dehydrated in the cylindrical body flows out to the end portion of the cylindrical body along the sheet surface, passes through the many drainage holes 26, and is discharged from the end surface of the take-up reel 16. The volume of the pressurizing chamber 12 increases in proportion to the supply amount of the pressure water, and at the same time the volume of the cylindrical body 14 decreases. Immediately after the maximum pressing force, for example, 60 kg / cm ² , the pressurization is completed in the lower half of FIG. To do. After this, the pressurized liquid in the pressurizing chamber 12 is transferred to the inlet / outlet 32.
The cylindrical body 14 after being removed from the pressure drum 10 is removed from the pressure drum 10. Then, the cylindrical body 14 is rewound, the dehydrated cake (dehydrated material to be dehydrated) is separated from the sheet S, and the sheet S is made reusable.

FIG. 5 is a schematic view schematically showing a process for manufacturing the cylindrical body 14 of the dehydrated product laminate. The sheet S is unrolled and unfolded from the roll 6, and the hopper is placed on the unfolded sheet S. The object to be dehydrated Q is lowered from the inside by means of the rotary vanes 7 in a thin layer state to spread the thin layer Q ₀ to be dehydrated on the sheet S, and the sheet S and the thin layer Q ₀ to be dehydrated thereon are put together. Cylindrical body 14 of a dehydrated product laminate wound on a take-up reel 16
To form.

[0015]

According to the dehydration method of the present invention, a dehydrated product laminate is formed by alternately laminating a large number of sheets and thin layers of the dehydrated product, and the dehydrated product laminate is formed in a direction substantially perpendicular to the sheet surface. Moisture is caused to flow out from the object to be dehydrated along the sheet surface. Moisture in the material to be dehydrated reaches the sheet surface by flowing through the material to be dehydrated for a short distance, and smoothly flows along the sheet surface to be discharged to the outside of the material to be dehydrated. Can be removed. Further, since pressure acts on the sheet surface from both front and back sides, damage due to the pressure does not occur, and since it is not necessary to allow moisture to flow across the sheet surface, clogging does not reduce efficiency. Further, by controlling the pressing force so that the dehydrated product laminate is compressed in proportion to the volume of the water flowing out, it is possible to prevent the dehydrated product from protruding from the end surface of the dehydrated product laminate.

In the dehydrating apparatus of the present invention, similarly, the water in the substance to be dehydrated reaches the sheet surface by flowing through the substance to be dehydrated for a short distance, and smoothly flows along the sheet surface to be dehydrated. Since it is discharged to the outside, it is possible to remove water by applying pressure for a short time. Further, since pressure acts on the sheet surface from both front and back sides, damage due to the pressure does not occur, and since it is not necessary to allow moisture to flow across the sheet surface, clogging does not reduce efficiency. Further, by controlling the pressing force so that the dehydrated product laminate is compressed in proportion to the volume of the water flowing out, it is possible to prevent the dehydrated product from protruding from the end surface of the dehydrated product laminate. It is possible to shorten the pressurizing time by reducing the thickness of the layer to be dehydrated. The dehydrated product laminate is formed efficiently by winding a sheet and a thin layer of the dehydrated product to form a cylindrical body in which a large number of sheets and thin layers of the dehydrated product are alternately stacked. It can be made into a small dehydrated product laminate, and by applying hydraulic pressure to the outer peripheral surface of the cylindrical body, the dehydrated product laminate is uniformly pressed and compressed to smoothly and efficiently separate water. It is possible to By providing a raised surface on the sheet surface, it is possible to easily separate the solid content of the dehydrated material from the sheet surface.

The compression dehydration method and apparatus of the present invention make it possible to dehydrate the substance to be dehydrated under pressure to a high pressure (about 60 kg / cm ² ) in a short time, and the water content of the dehydrated cake obtained is 50% or less. It can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a dehydrated product laminate according to an embodiment of the present invention.

2A to 2C are schematic cross-sectional views showing a dehydration process for one thin layer Qm in the dehydrated product laminate of the example of FIG. 1, and FIG. 2B is under pressure, FIG.
C is a cross-sectional view of a state after pressurization.

3A and 3B are schematic sectional views showing a dehydrating step of a cylindrical body of a dehydrated article laminate in another embodiment of the present invention, FIG. 3A being before pressurization and FIG. It is sectional drawing which shows after pressing.

FIG. 4 is an illustrative cross-sectional view showing a side cross section of the cylindrical body of the dehydrated laminate before pressure is applied, and a lower half of FIG. 4 is a side cross section of the cylinder after pressure applied. It is a schematic cross-sectional view showing.

FIG. 5 is a schematic diagram schematically showing a step of producing a cylindrical body of a dehydrated product laminate.

[Explanation of symbols]

2: Dehydrated laminate, 6: Roll, 7: Rotating blade, 8:
Hopper, 10: pressure resistant drum, 12: pressure chamber, 14: cylindrical body, 16: winding reel, 22: pressure resistant end surface, 24: rubber film, 26: drainage hole, 32: pressurized liquid inlet / outlet, F: moisture. Flow, W: moisture, S1, S2, ... Sn, Sn + 1:
Sheets, Q: Items to be dehydrated, Q ₀ , Q 1, Q 2 ... Qn:
Thin layer of material to be dehydrated, P: Pressing force.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-247811 (JP, A) JP 4-341399 (JP, A) Actually opened 60-176897 (JP, U) Actually opened 62- 184000 (JP, U) Actually open 61-159010 (JP, U) Actually open 1-171611 (JP, U) Japanese public Sho-1-16600 (JP, B2)

Claims (8)

(57) [Claims] 1. A dehydration method for compressing a substance to be dehydrated containing water and solids and having low fluidity to remove moisture from the substance to be dehydrated, and to obtain a sheet having fine irregularities along which the moisture can flow. The step of preparing, the step of forming a laminate to be dehydrated by stacking a large number of sheets and thin layers of the article to be dehydrated alternately, and the article to be dehydrated compressed by pressing the laminate to be dehydrated in a direction substantially perpendicular to the sheet surface. And a step of removing water that has flowed out along the surface of the sheet. 2. The dehydration method according to claim 1, wherein the step of forming the dehydrated product laminate comprises winding a sheet and a thin layer of the dehydrated product together to form a cylindrical body of the dehydrated product laminate. A method comprising the steps of forming and pressing the laminate to be dehydrated by applying a hydraulic pressure to the outer peripheral surface of the cylindrical body. 3. The dehydration method according to claim 2, wherein the step of exerting hydraulic pressure on the outer peripheral surface of the cylindrical body comprises the step of disposing a stretchable film body in contact with the outer peripheral surface of the cylindrical body, A method comprising placing a pressure vessel surrounding the body, providing a pressure chamber between the membrane body and the inner surface of the pressure vessel, and supplying a pressurized liquid to the pressure chamber. 4. The dehydration method according to claim 1, wherein the step of pressing the dehydrated product laminate compresses in proportion to a volume of water flowing out from the dehydrated product laminate. A method for dehydration, comprising the step of controlling the applied pressure as described above. 5. A sheet having fine irregularities capable of flowing water along a sheet surface, which is a dehydration device for compressing an article to be dehydrated containing water and solids and having low fluidity to remove water from the article to be dehydrated. A means for pressing and compressing a dehydrated product laminate in which a large number of thin layers of the dehydrated product are alternately stacked, and a dehydrated product laminate from the compressed dehydrated product laminate A dehydrator including means for removing water flowing out to the end of the. 6. The dehydration apparatus according to claim 5, wherein the dehydrated product laminate is composed of a cylindrical body in which a large number of sheets and thin layers of the dehydrated product are alternately and substantially concentrically stacked. The device for compressing a body is constituted by a device for exerting hydraulic pressure on an outer peripheral surface of a cylindrical body. 7. The dehydrator according to claim 6, wherein the means for exerting hydraulic pressure on the outer peripheral surface of the cylindrical body is a stretchable membrane body or a membrane body arranged in contact with the outer peripheral surface of the cylindrical body. An apparatus comprising: a pressure-resistant container disposed so as to surround the pressure chamber, a pressurizing chamber provided between the film body and the inner surface of the pressure-resistant container, and means for supplying a pressure liquid to the pressurizing chamber. 8. The dehydrating apparatus according to claim 5, wherein the sheets in the dehydrated product laminate are provided with naps so that the solid content of the dehydrated products can be easily separated from the sheet surface after dehydration. A dehydrator characterized by the above.