JPH1015598A - Method and apparatus for dehydrating muddy substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform treatment reducing the water content ratio of a solid by arranging a metal net cage inner cylinder made of a metal within a steel metal outer cylinder fitted with a lid and laying filter cloth on the inside of the inner cylinder 5 to charge a muddy substance so as to enclose the filter cloth and by intermittently performing a vacuum suction through the suction drain holes provided to the outer cylinder. SOLUTION: When sludge is subjected to dehydration treatment, a predetermined amt. of a muddy substance 24 is charged into an inner cylinder 10 and the valve 25 of the supply pipe is closed. In this state, static pressure is applied to the muddy substance 24 and contained water is filtered by the filter cloth 15 to be discharged to the outer cylinder 1 from the meshes of the metal mesh plate 12 of the inner cylinder 10 but, at this time, the interior of the outer cylinder 1 is set to a vacuum state by a vacuum water suction apparatus 19. By this constitution, the moisture in the muddy substrate 24 is forcibly sucked from the inner cylinder 10 to be led out into the tank of the vacuum water sucking apparatus 19 through the suction drain port 2. At this time, since the moisture at the central part of the muddy substance 24 is hard to suck, the water gathering apparatus 20 is placed in the muddy like substance 24 and moisture is sucked from the vacuum water suction apparatus 19 to be discharged as a drain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to civil engineering, sludge generated in construction works, sludge generated in sewage treatment plants, sludge deposited in lakes, rivers, rivers, etc., effluent from agricultural and marine food processing, and metal sludge slurry. The present invention relates to a method for dewatering a sludge material which dewaters a sludge material such as a factory waste liquid as much as possible to reduce the water content of solids and facilitate the treatment.

[0002]

2. Description of the Related Art Conventionally, methods for dewatering sludge substances include sun drying, heat dehydration using a hot air drier, pressure dehydration using a filter press and belt press, vacuum dehydration using a rotary vacuum dehydrator, cyclone (centrifugal centrifugation). Centrifugal separation by a dehydrator), vibration dehydration by a vibrating sieve, solidification treatment by addition of cement, and addition of a chemical for separation by a coagulant.

[0003] In the method of drying in the sun, water is evaporated over a long period of time on a large site.
It has a bad smell and is inefficient due to the weather. Even with mechanical treatment methods such as heat dehydration and pressure dehydration, the dehydration effect is insufficient, a large processing space is required for installing the apparatus, and the processing cost is large. Further, the treatment with the additive / solidifying agent has many problems such as deterioration of the chemical properties of the muddy substance. In addition, the water content of the dehydrated solids is high and cannot be used for landfills or embankments, and industrial wastes must be treated in many cases.

[0004]

In contrast to these methods, a treatment method by vacuum dehydration is relatively effective. For example, the outside of a rotating screen drum is brought into contact with sludge in a dehydration tank, What is sucked by a vacuum pipe in a drum and discharged as a dewatered cake has been used for a long time in sewage treatment plants and the like, and dewatering may not be sufficient.

[0005] As another treatment method by vacuum dehydration, a method has been proposed in which the boiling point of sludge is lowered by vacuum and a heating medium such as steam is brought into contact with the periphery of the container to promote dehydration. Equipment becomes complicated,
There are problems such as high processing costs.

An object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, and to further reduce the processing cost by using a vacuum dehydration processing method, and to reduce the water content of the solid after the processing. Process can be realized, the device is relatively simple, the device can be installed on a small site due to the miniaturization of the device, and the chemical properties are deteriorated due to the flocculant and the solidifying agent. It is an object of the present invention to provide a method and an apparatus for dewatering a muddy substance that do not have any problem.

[0007]

According to the present invention, in order to achieve the above object, as a method for dehydrating a mud-like substance, first, a metal net cage-like inner cylinder is disposed in a steel outer cylinder with a lid. Laying a filter cloth in the inner cylinder, charging a muddy substance to be wrapped with the filter cloth, and intermittently vacuum-suctioning through an intake / drain hole provided in the outer cylinder. First, the filter cloth is provided with a mesh bag inside the inner cylinder and laid therein. Third, an air hole is formed in the lid, and the air hole is opened intermittently or the lid is closed. Fourth, an air hole is formed, and compressed air is intermittently blown into the outer cylinder through the air hole. Fourthly, a water collecting device is arranged in the muddy substance, and even from inside the muddy substance by the vacuum force. Fifth, promote the dehydration. Fifth, the inner cylinder is partitioned into a lower muddy substance input section and an upper air layer section by a flexible barrier film, and compressed air is supplied to the upper air layer section. Is it is intended to subject matter that pressurize the mud-like substance.

[0008] As a mud-like substance dehydrating apparatus, first, a steel outer cylinder provided with a lid on the upper side, and formed with an intake / drainage hole connected to a vacuum water absorbing device on the lower side, and disposed inside the outer cylinder. Secondly, an air hole for opening the outside air is formed in the lid, which comprises a metal mesh basket-shaped inner cylinder for charging a muddy substance with a mesh bag inside and a filter cloth laid therein. Or forming an air hole in the lid to be connected to the compressor, thirdly, disposing a water collecting device in the inner cylinder, and fourthly, the lower muddy material in the inner cylinder with a flexible barrier film. The gist of the present invention is to partition into an input section and an upper air layer section.

According to the first and seventh aspects of the present invention, a treatment method by vacuum dehydration is performed by vacuum suction through an intake / drain hole provided in an outer cylinder. By laying a filter cloth in it and putting a muddy substance so as to wrap it with this filter cloth, a so-called hydrostatic dehydration treatment in which the water content passes through the filter cloth and is discharged even as it is is added. Can reduce the water content of the solid content.

In the continuous operation, the mesh of the inner cylinder and the filter cloth may be clogged and water may not be discharged. However, such clogging can be prevented by intermittent vacuum suction.

According to the second aspect of the present invention, in order to treat the residual solid in addition to the above operation, the net bag may be lifted from the inner cylinder and transported as it is. Separation and recovery of objects can be performed in one step.

According to the third and eighth aspects of the present invention, in addition to the above-described operation, during the period when the vacuum suction is performed intermittently, an air hole is opened to introduce outside air, thereby allowing a filter cloth or the like to be formed. Atmospheric pressure is applied from outside to prevent clogging efficiently.

According to the present invention as set forth in claim 4 and claim 9, during the intermittent vacuum suction, compressed air is blown into the outer cylinder to pressurize the compressed air from outside to the filter cloth or the like. And clogging can be efficiently prevented.

According to the fifth and tenth aspects of the present invention, the water collecting device is disposed in the muddy substance, and dehydration is promoted from the inside of the muddy substance by the vacuum force, whereby the dewatering effect is insufficient. Consideration can also be given to muddy substances, which tend to be less prone.

According to the sixth and eleventh aspects of the present invention, the flexible barrier film is used to partition the lower muddy substance introduction section and the upper air layer section, and compressed air is introduced into the upper air layer section. In addition to the action of the vacuum suction, dehydration can be further promoted by pressurizing the muddy substance.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view showing a first embodiment of a method and an apparatus for dewatering a muddy substance according to the present invention, FIG. 2 is a vertical sectional side view of a main part of the same, and FIG. 3 is a sectional view taken along line AA 'of FIG. Reference numeral 4 is a sectional view taken along the line BB 'of the above, and the device of the present invention will be described first.

In the figure, reference numeral 1 denotes a steel outer cylinder, and an intake / drainage hole 2 is provided at the bottom.
A base table 3 and a flange 4 for holding an inner cylinder 10 described later with a certain gap are provided inside.

Further, a lid 5 is provided on the upper end open surface of the outer cylinder 1 so as to be airtightly closed by a fixing bolt 6, and the lid 5 has a material charging hole 7, an air hole 8 and a water collecting hole in the center. A pipe hole 9 was formed.

In the figure, reference numeral 10 denotes an inner cylinder installed in the outer cylinder 1.
As shown in FIG. 6, a metal mesh basket-like body is provided in which a metal mesh plate 12 is stretched on a frame 11 composed of a horizontal member 11a and a vertical member 11b. In the figure, reference numeral 13 denotes a ring-shaped hanging member provided at the upper end of the inner cylinder 10.

In the inner cylinder 10, a coarse mesh bag 14 such as a braided knitted cord is disposed, and a filter cloth 15 is further laid therein. The filter cloth 15 is preferably a polypropylene continuous fiber nonwoven fabric using polypropylene as a raw material. The filter cloth 15 may be formed in a bag.

Further, a supply pipe 16 for muddy substance is connected to the material charging hole 7, and a compressor 18 is connected to the air hole 8 via an air intake valve 17a using a three-way cock. Further, a vacuum water absorbing device 19 is connected to the intake / drain hole 2 via a water absorbing pipe 21 provided with an air intake valve 17b in the middle.

A water collecting device 20 such as a well port is disposed at the center of the inner cylinder 10 and its water supply hose 20a is connected to the inside of a water collecting pipe hole 9 provided in the lid 5 and further the water collecting pipe The hole 9 branches the water-absorbing pipe 21 from the vacuum water-absorbing device 19 and connects to the end thereof. In the figure, reference numeral 22 denotes a switching valve provided in the water-absorbing pipe 21 which branches.

The motor 18a and the air intake valves 17a and 17b of the compressor 18 and the vacuum water absorbing device 19 are connected to a control device 23 for automatic operation control.

Next, the method of the present invention using such an apparatus will be described. A predetermined amount of muddy substance 24 is supplied from a mud storage tank (not shown) through the supply pipe 16 and the material charging hole 7 so as to be wrapped with the filter cloth 15 in the inner cylinder 10. Close.

In this state, a static pressure is applied to the muddy substance 24, and the water content is filtered by the filter cloth 15, and the metal mesh plate of the inner cylinder 10 is formed.
The water is discharged from the mesh of 12 to the outer cylinder 1, and the vacuum water absorbing device 19 is further operated to make the inside of the outer cylinder 1 into a high vacuum state. As a result, the water in the muddy substance 24 is further forcibly sucked from the periphery and the bottom of the inner cylinder 10 and guided into the tank in the vacuum water absorbing device 19 through the lower intake / drainage hole 2.

In such an operation, it is considered that the water in the central portion of the muddy substance 24 is difficult to be sucked. Therefore, the water collecting device 20 is arranged in the muddy substance 24 and the water collecting device 20 is transferred to the vacuum water absorbing device 19. The water in the muddy substance 24 is sucked from the water collecting device 20. The waste water sucked into the vacuum water absorbing device 19 is treated on a discharge basis and discharged to sewage.

The weave of the filter cloth 15 and the mesh of the metal mesh plate 12 are likely to be clogged depending on the size of the mesh.
As a countermeasure, it is conceivable to wash the mesh of the filter cloth 15 and the mesh of the metal mesh plate 12, but a washing device is required,
The device becomes complicated. Therefore, in the present invention, the vacuum water absorbing device 19
The vacuum suction is performed intermittently. During the pause operation, the air hole 8 is opened by the air intake valve 17a, and the air intake valve 17b is also opened to rapidly bring the inside of the outer cylinder 1 to atmospheric pressure. Thus, atmospheric pressure is applied from the outside of the inner cylinder 10 to push back fine particles clogged in the eyes, thereby preventing clogging.

In another embodiment, the air hole 8 is connected to a compressor 18 without opening the air hole 8.
Alternatively, the compressed air may be blown into the outer cylinder 1 to apply the pressure of the compressed air from the outside of the inner cylinder 10 to efficiently prevent the clogging. Opening the air hole 8 and connecting it to the compressor 18 may be appropriately combined.

The solid content remaining after the treatment by vacuum dehydration and thus lowering the water content in this manner is reduced to an inner cylinder 10
Is lifted and loaded into a transport device such as a transport vehicle or a belt conveyor, or the inner bag 10 is left and the mesh bag 14 is lifted together with the filter cloth 15 and discharged.

As another method of discharging the remaining solid content, a hydraulic opening / closing device may be provided at the bottom of the inner cylinder 10 or the outer cylinder 1 and opened / closed to take out.

FIG. 5 shows a second embodiment of the present invention. The inside of the inner cylinder 10 is divided into a lower mud-like substance introduction section 27 and an upper air layer section 28 by a flexible barrier film 26 formed in a bellows. I do.

The material supply hole 7 provided in the lid 5 and the supply hole 29 provided at the upper end of the lower muddy substance supply portion 27 are communicated by a flexible tube 30. An appropriate number of air holes 31 are formed in the flexible barrier film 26 so as to connect the boundary between the mud-like substance input section 27 and the upper air layer section 28. Further, the mesh bag 14 is disposed in the lower muddy substance charging section 27 as in the first embodiment, and the filter cloth 15 is further laid therein.

Compressed air is supplied from the compressor 18 to the upper air layer 28 through the air hole 8 to inflate the upper air layer 28 and pressurize the muddy substance 24 in the lower muddy substance charging section 27. At this time, the compressed air also flows from the air holes 31 to the lower muddy substance input section 27, and passes through the muddy substances 24 to form fine air holes therein, thereby promoting dehydration.

As described above, in the second embodiment, the vacuum water absorbing device is used.
In addition to the vacuum suction in step 19, dehydration is performed by pressing the flexible blocking film 26.

In the case where the volume of the muddy substance 24 is significantly reduced by such a treatment, the muddy substance 24 is further supplied on the dewatered muddy substance 24 to continue the same dehydration.

[0036]

As described above, the method and apparatus for dewatering a muddy substance according to the present invention can achieve the following effects.

First, the apparatus is relatively simple, and since no chemical such as a coagulant is used, initial costs and running costs can be reduced, and processing costs can be reduced.

Secondly, in the case of sludge generated during construction work or the like, the water content of the sludge after treatment is low, and the sludge is similar to ordinary soil, and can be used for embankment and the like.

Thirdly, the downsizing of the apparatus makes it possible to install the apparatus even on a small site, and fourthly, strong oxidation by a coagulant or a solidifying material or neutralization of a strongly alkalized muddy substance becomes unnecessary. Non-use is possible.

Fourth, when the solid content of the dewatered muddy substance is incinerated, since the water content is reduced, the heating energy can be reduced, and the incineration energy can be saved.

[Brief description of the drawings]

FIG. 1 is a first diagram illustrating a method and an apparatus for dewatering a muddy substance according to the present invention.
It is explanatory drawing which shows embodiment.

FIG. 2 is a first diagram illustrating a method and an apparatus for dewatering a muddy substance according to the present invention.
It is a longitudinal side view of the important section showing an embodiment.

FIG. 3 is a sectional view taken along line AA ′ of FIG. 2;

FIG. 4 is a sectional view taken along line BB ′ of FIG. 2;

FIG. 5 is a diagram showing a second example of the method and apparatus for dewatering a muddy substance according to the present invention
It is a longitudinal side view of the important section showing an embodiment.

FIG. 6 is a perspective view showing an example of an inner cylinder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer cylinder 2 ... Intake drainage hole 3 ... Foundation base 4 ... Flange 5 ... Lid 6 ... Fixing bolt 7 ... Input hole 8 ... Air hole 9 ... Water collecting pipe hole 10 ... Inner cylinder 11 ... Frame 11a ... Horizontal material 11b ... Vertical member 12 ... Metal mesh plate 13 ... Hanging tool 14 ... Mesh bag 15 ... Filter cloth 16 ... Supply pipe 17a, 17b ... Air intake valve 18 ... Compressor 19 ... Vacuum water absorbing device 19a ... Motor 20 ... Water collecting device 20a ... Water hose 21 ... water absorption pipe 22 ... switching valve 23 ... control device 24 ... muddy substance 25 ... valve 26 ... flexible barrier film 27 ... lower muddy substance input part 28 ... upper air layer part 29 ... input hole 30 ... flexible pipe 31 ... air hole

Claims (11)

[Claims] 1. A metal net cage-shaped inner cylinder is disposed in a steel outer cylinder with a lid, and a filter cloth is laid in the inner cylinder, and a mud-like substance is charged so as to be wrapped with the filter cloth. And a method of dehydrating a muddy substance, wherein vacuum suction is performed intermittently through an intake / drain hole provided in an outer cylinder. 2. The method for dewatering a muddy substance according to claim 1, wherein the filter cloth is first provided with a mesh bag in the inner cylinder and laid therein. 3. The method according to claim 1, wherein an air hole is formed in the lid, and the air hole is intermittently opened. 4. The method for dewatering a muddy substance according to claim 1, wherein an air hole is formed in the lid, and compressed air is intermittently blown into the outer cylinder through the air hole. 5. The method for dewatering a muddy substance according to claim 1, wherein a water collecting device is disposed in the muddy substance, and dehydration is promoted from inside the muddy substance by a vacuum force. 6. The inner cylinder is partitioned into a lower muddy substance input section and an upper air layer section by a flexible barrier film, and compressed air is injected into the upper air layer section to pressurize the muddy substance. The method for dehydrating a muddy substance according to claim 1 or 3. 7. A steel outer cylinder provided with a lid on the upper side and having an intake / drainage hole connected to a vacuum water absorbing device on a lower side, a net bag disposed inside the outer cylinder, and a mesh bag therein, and a mesh bag therein. A muddy substance dewatering device comprising a metal mesh basket-shaped inner cylinder for charging a muddy substance, on which a filter cloth is laid. 8. The dewatering apparatus for muddy substances according to claim 7, wherein an air hole for opening the outside air is formed in the lid. 9. The muddy substance dewatering apparatus according to claim 7, wherein an air hole connected to the compressor is formed in the lid. 10. The water collecting device is disposed in the inner cylinder.
An apparatus for dehydrating a muddy substance according to claim 9. 11. The dewatering apparatus for muddy substance according to claim 7, wherein the inner cylinder is partitioned into a lower muddy substance charging section and an upper air layer section by a flexible barrier film.