JP2001198600A - Sludge drying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that many days have been taken to dry sludge in the sun in a concrete pool since the water from the sludge is evaporated only from the upper face. SOLUTION: Sludge A is introduced into a filter vessel 10 with a filter cloth 12 impermeable to sand and permeable to water and air laid over the inside, the sludge-containing filter vessel 1 is separated from the ground to drip the water in the sludge A through the filter cloth 12 by gravity, then the water remaining in the sludge A is evaporated from the upper face opened to the atmosphere and the contact face of the filter cloth 12, and the sludge is dried in the sun. Consequently, the evaporation area of the sludge A is increased, and the drying days are decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge drying method for drying sludge generated in, for example, a water purification plant, a sewage treatment plant, or a factory.

[0002]

2. Description of the Related Art Sludge pumped from water has a water content of as high as 95 to 97%, and the next treatment cannot be carried out with the high water content.
High water sludge needs to be dried (or dewatered).
Conventionally, sludge drying methods include a method of naturally drying sludge in the sun and a method of mechanically compressing and filtering sludge.

[0003] In the conventional method of drying sludge by sun drying, generally, sand is spread on the bottom of a concrete pool, and the sludge pumped on the sand is dried in the sun. In addition, the water in the sludge permeates through the space of the bed sand and flows out from the pool bottom, and gradually evaporates as steam from the upper surface of the sludge which comes into contact with the air.

[0004] In such a conventional method of drying sludge by the sun, the sludge to be dried in the pool only contacts the air on the upper surface thereof, so that the drying efficiency by evaporation is very poor. By the way, in the pool, for example, 50cm in thickness
If the sludge is dried in the sun, it may take a long or short time depending on the season, but it takes 5 to 6 months on average each time, and if the sludge is thick, it can only be dried to a final moisture content of about 50%. .

[0005] In addition, in the method of drying the sun by putting sludge into a pool as described above, if the amount of sludge per unit area is increased (thickness is increased), the number of days for drying to the center of the sludge is accelerated. And the rotation efficiency of the sludge drying place is deteriorated (the sludge drying treatment amount per unit area is small). Therefore, in the conventional solar drying method, it is necessary to secure a large-area treatment place corresponding to the amount of the sludge that is sequentially generated in order to dry the sludge.

On the other hand, in the method of mechanically compressing and filtering sludge, the mechanical equipment becomes large and high pressure is applied to the filtering material, so that the durable period of the filtering material is shortened. However, there is a problem that it is expensive.

[0007] The invention of the present application, when drying the sludge in the sun,
It is a first object of the present invention to provide a sludge drying method capable of improving the drying efficiency per hour by promoting the evaporation of water in the sludge, and can increase the sludge drying treatment amount per hour in a small site area. A second object is to provide a method for drying sludge as described above.

[0008]

The present invention has the following structure as means for solving the above-mentioned problems. The invention of claim 1 of the present application The invention of claim 1 of the present application is directed to a method of drying sludge by solar drying. According to the sludge drying method of the first aspect, sludge is contained in a filter container provided with a filter cloth which prevents passage of sand and allows water and air to pass therethrough, and separates the filter container containing the sludge from the ground. After the water in the sludge is naturally dropped through the filter cloth, the remaining moisture in the sludge is dried in the sun while evaporating from the upper surface open to the atmosphere and the contact surface of the filter cloth.

The filtration container used in the sludge drying method of the first aspect is not particularly limited, but is, for example, 2 m.
A relatively thin one having an area of about 3 to 4 m and a height of about 20 to 30 cm is preferable. Then, the filtration container is filled with sludge in a range of, for example, 10 to 20 cm.

The filter container containing sludge is naturally dried while being separated from the ground, but when the sludge pumped from the water is filled in the filter container, water in the sludge drops downward through the filter cloth of the filter container. I do. In addition, if the sludge thickness in a filtration container is about 10-20 cm, dripping of water will be completed in about 2-3 days. After that, the water in the sludge evaporates not only from the top surface of the sludge but also from the side peripheral surface and the bottom surface of the filter cloth. That is, in the sludge drying method of claim 1 of the present application, after the completion of the dropping of water, the area of the sludge that comes into contact with the outside air (evaporation area of water) is greatly increased, and the evaporation efficiency (drying efficiency) of the water in the sludge is good. Becomes The invention according to claim 2 of the present invention is directed to the method for drying sludge according to claim 1, wherein a plurality of shelves in which filter containers containing sludge are superimposed and arranged at intervals above and below are arranged from the lower shelf side to the upper shelf side. Sun drying while moving sequentially to the side.

In the sludge drying method according to the second aspect, the shelves are
Use a drying building with more than one stage. In the case of the second aspect, a lifter device may be used to sequentially move the sludge-containing filtration container from the lower shelf to the upper shelf.
Then, the high-hydrated sludge filtration container that has just been pumped out of the water is placed on the bottom shelf, drained there for several days, and the ones that have been dropped are sequentially moved to the upper shelf. . When the shelves are full, it is only necessary to remove the uppermost dried sludge-containing filtration container from the shelf, and then place the next sludge-containing filtration container on the upper shelf.

In the method for drying sludge according to the second aspect of the present invention,
Since the sludge-containing filtration container is dried on a plurality of shelves vertically polymerized, the sludge drying treatment amount per unit site area increases, and the site can be used effectively. The invention according to claim 3 of the present invention is directed to the method for drying sludge according to claim 1, wherein the sludge-containing filtration containers are placed on a plurality of shelves, each of which is superimposed and arranged at an interval above and below, and each sludge-containing filtration container is filtered. Each container is dried in the sun in a fixed position.

In the method for drying sludge according to the third aspect of the present invention, the roof plate is disposed between the upper and lower shelves, and the water dropped from the filter container containing the sludge placed on the upper shelf is placed on the lower shelf. Dry in the sun while keeping out of the filter container.

In the sludge drying method according to the third aspect of the present invention, the water in the sludge is dropped through the filter cloth of the filter container because the filter container with sludge which has not been drained is placed on each shelf as it is. Is received by the shingle installed between the upper shelf and the lower shelf. Therefore, even if the water dropped from the sludge-filled filter container on the upper shelf does not enter the sludge-filled filter container on the lower shelf, the water is dried on each shelf (fixed position). The dripping water does not slow down the drying speed of the lower sludge.
In the sludge drying method according to the third aspect, the sludge-containing filtration container is dried on a plurality of shelves that vertically polymerize, so that the sun can be efficiently dried in a small site area.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The sludge drying method according to an embodiment of the present invention will be described with reference to FIGS.
An embodiment (corresponding to claim 1) is shown, and FIGS. 3 and 4 show a second embodiment (corresponding to claim 2),
5 and 6 show a third embodiment (corresponding to claim 3).
It is shown. First Embodiment The sludge drying method according to the first embodiment is performed using, for example, a filtration container 10 as shown in FIG. This filtration container 10
Receiving basket 11 formed by assembling fine steel bars in a rectangular shallow dish shape
And a shallow dish-shaped filter cloth 1 housed in the receiving basket 11
And 2. The size and shape of the filtration container 10 are not particularly limited, but in the embodiment shown in FIGS. 1 and 2, a square having an area of about 2 m × 3 m and a height of about 20 cm is used. Use things.

The filter cloth 12 is formed of a mesh-shaped filter medium that blocks passage of sand and allows passage of liquid and air. The receiving basket 11 is for ensuring the shape retention of the filter cloth 12, and the filter cloth 12 fits in the receiving basket 11 without any excess or shortage.

The sludge drying method of the first embodiment shown in FIG. 2 is performed as follows. First, the receiving basket 11 shown in FIG.
The filter container 10 is configured by assembling the filter cloth 12 therein,
A predetermined amount (for example, a thickness of about 15 cm) of the sludge A is stored in the filtration container 10. Next, the sludge-containing filtration container 1 is placed on the shelf 13 and separated from the ground. Then, in the initial stage, as shown by the symbol W, the water in the sludge A
2 is dropped naturally, for example, when the thickness of sludge A is 10
If it is about 15 cm, the dripping of water W stops in about 2 to 3 days. And after that, the residual moisture in the sludge A is
As indicated by reference symbol S, the solar cell is dried in the sun while evaporating from the upper surface side and the filter cloth contact surface (side peripheral surface and lower surface) opened to the atmosphere.

Therefore, according to the sludge drying method of the first embodiment of the present invention, the sludge A is put into the filtration vessel 10 and dried in order to dry the sludge in the sun.
However, the area (evaporation area of water) in contact with the outside air is greatly increased, and the efficiency of evaporation of water in the sludge is improved (the drying time is shortened).

In the experiment in which the sludge A was stored in the filtration container 10 at a thickness of about 15 cm, cracks began to be generated in the dried sludge A after about 4 to 5 days, and the area in contact with the outside air was started. And the evaporation effect was further promoted.
Then, one month later, the water content of the sludge A became 23.6%. By the way, when the sludge A is dried so far, the sludge component becomes powdery when crushed. Therefore, when this dried sludge is used, for example, as a raw material for bricks, the miscibility with other materials is improved. Second Embodiment The sludge drying method according to the second embodiment shown in FIG. 3 and FIG.
(The method of drying by placing in a cabinet) and drying on the sun while moving on a plurality of shelves.

That is, in the second embodiment, a plurality of shelves 2
The drying is performed by using a drying ridge 2 in which 1 to 24 are arranged one above the other. That is, in the embodiment shown in FIG. 3 and FIG.
Has four shelves 21, 22, 23, and 24 at the top and bottom, and each of the shelves 21 to 24 has three filtration containers 1 containing sludge.
Has a space for mounting. At the left and right ends of the drying building 2, filtration containers 1 containing sludge are placed on shelves 21 to 2 of each stage.
Lifter device 25L, 2 for raising and lowering to the height of 4
5R are arranged respectively. This lifter device 2
5L and 25R are for raising and lowering the mounting table 26L (or 26R) for mounting the sludge-containing filtration container 1, and
In the illustrated example, a pantograph type is adopted. Each lifter device 25L, the 25R, left and right of the platform 26L, code L ₁ 26R to each view 4 ~L ₄ (or R ₁ to R ₄₎ flush with the shelf 21 to 24 of each stage, as shown by So that it can be matched. Also, each mounting table 26L, 2
6R, the filtration container 1 containing sludge is placed on each of the shelves 21 to 2
Supply / discharge device 27L (or 27R) for taking in and out of 4
Is provided.

Then, the sludge drying method of the second embodiment is performed as follows. First, the sludge A having a high water content is put into the filtration vessel 10, and the filtration vessel 1 containing the sludge is placed on the mounting table 26L of the left lifter device 25L. The filtration vessel 1 containing the sludge is placed on the first shelf by the supply / discharge device 27L. 21 entrance 21
a to the first shelf 21. Similarly, on the first shelf 21, three sludge-filled filtration containers 1 are sequentially stacked in a bead shape.
Send. In this state, water in the sludge A (FIG. 2) of each of the sludge-containing filtration containers 1, 1, 1 placed on the first shelf 21 drops through the filter cloth 12 (FIGS. 1, 2), and ~ 3
After a day, the dripping of the water from the sludge-containing filtration container 1 ends.

Thereafter, the next filtration container 1 containing high-humidity sludge is placed on the left-hand support 26L, and the filtration container 1 containing sludge is sent to the inlet 21a side of the first shelf 21. Then, the first
The drained sludge-containing filtration container 1 at the outlet 21b of the step shelf 21 is pushed out onto the right-side support 26R, and the right-side support 26R on which the sludge-containing filter container 1 is mounted is moved to the second stage shelf by the right lifter device 25R. height of 22 (height of the sign R ₂₎
And the supply / discharge device 27R is operated to the feed side to feed the sludge-containing filtration container 1 to the inlet 22a of the second shelf 22. Similarly, the operation of feeding the filtration container 1 containing high-humidity sludge into the inlet 21a of the first shelf 21 and the operation of the first shelf 21
To perform the discharge operation and from the outlet 21b to the draining already sludge containing filtering vessel 1 of the right stand 26R on, raising the → right stand 26R to the height of the code R _2, → the sludge containing the filtering vessel first It is sent to the entrance 22a side of the second shelf 22.
At this time, the sludge-containing filtration container 1 previously placed on the second shelf 22 is pushed to the back side in a ball-shaped manner.

In the same manner, the entrance 2 of the first shelf 21
1a, the filtration container 1 containing high water content sludge is sent in, and the filtration container 1 containing sludge in each shelf is sequentially moved or raised horizontally, and finally the shelves 21 to 21 shown in FIG.
24, the sludge-filled filtration container 1 is filled and dried in the sun. After the sludge-containing filtration container 1 is sent into the inlet 21a of the first shelf 21, the outlet 24 of the uppermost shelf 24 is turned off.
If it takes about one month to be extruded before being extruded from b, the sludge A in the filtration container 10 can be dried to a sufficient degree of drying.

The dried sludge-containing filtration container 1 at the outlet 24b of the uppermost shelf 24 is discharged as follows. That is, the left stand 26L up to the height of the code L ₄ allowed to move upward, the sign R ₄ in a state carrying the sludge-containing filtration container 1 is discharged from the outlet 23b of the third Dantana 23 to the right stand 26R The sludge-filled filtration container 1 on the right-hand mounting table 26R is sent to the inlet 24a side of the uppermost shelf 24 by the supply / discharge device 27R.
Then, the dried sludge-containing filtration container 1 corresponding to b is transferred to the left-hand mounting table 26L in the shape of a bead. Incidentally, the sludge-containing filtration container 1 placed on the left stand 26L at the position of the height L ₄ are, halfway automatically invert (turn over) to lower the left side stand 26L, drying of the filter vessel 10 The sludge A may be transferred to a predetermined container (or truck bed).

As described above, when the sludge-containing filtration container 1 is dried in the sun while being sequentially moved from the lower stage to the upper stage of each of the shelves 21 to 24, the sludge is dropped from the initial filtration container 1 containing high water content sludge. Water is completely cut off at the first shelf 21 and water does not drop from the sludge-containing filtration container 1 placed at a height higher than the second shelf 22. In addition, since the sludge-containing filtration container 1 is dried on a plurality of shelves 21 to 24 that are vertically polymerized, the sludge drying treatment amount per unit site area increases, and the site can be used effectively. Third Embodiment The sludge drying method according to the third embodiment shown in FIG. 5 and FIG.
And drying it in the sun by placing it on a plurality of shelves in a fixed state.

In the third embodiment, for example, a drying building 3 having two upper and lower shelves 31, 32 is used. On the shelves 31 and 32 of each stage of the drying building 3, there are placed the sludge-containing filtration container 1 having a total of six sections, three sections in front and rear as shown in FIG. 5 and two sections on the left and right as shown in FIG. Space is provided.
In other embodiments, the shelves 31, 32 in the drying building 3 are used.
Of course, and the number of spaces for placing the sludge-containing filtration container 1 on each of the shelves 31 and 32 can of course be changed as appropriate.

In the third embodiment, two left and right lifters 25L and 25R are used as shown in FIG. (The left-right direction in FIG. 5). The structure of the lifter device basically has substantially the same function as that shown in FIG. 4, and the sludge-containing filtration container 1 can be taken in and out of the shelves 31 and 32.

In the drying building 3, a roof plate 33 is arranged between upper and lower shelves 31, 32. The roof plate 33 between the shelves 31 and 32 prevents water dripping from the sludge-filled filtration container 1 placed on the upper shelf 32 from entering the sludge-filled filtration container 1 placed on the lower shelf 31. , Upper shelf 32
Has an area that can cover the area of

Then, in the sludge drying method of the third embodiment, the sludge-filled filtration container 1 which is not drained is placed on the shelves 31 and 32 as it is, and at this time, water in the sludge A (FIG. 2) is discharged. The solution is dropped through the filter cloth 12 of the filter container 10. However, the dropped water is received by the roof plate 33 installed between the upper shelf 32 and the lower shelf 31, and the water dropped from the sludge-filled filtration container 1 on the upper shelf 32 becomes the lower shelf 31. It does not enter the upper sludge-containing filtration container 1. Therefore, the sludge-containing filtration container 1 is stored in each of the shelves 3
Even if the drying is performed at a fixed position on the first and the second 32, the dripping water does not slow down the drying speed of the lower sludge. In the sludge drying method of the third embodiment as well, the sludge-containing filtration container 1 is dried on a plurality of shelves 31 and 32 which are vertically polymerized, so that the sun is efficiently dried on a small site area. be able to.

[0030]

The sludge drying method of the present invention has the following effects. According to the method for drying sludge of the present invention, sludge A is contained in a filter container 10 covered with a filter cloth 12, and the sludge-containing filter container 1 is separated from the ground to remove sludge A. After allowing the water inside to drop naturally through the filter cloth 12, the remaining water in the sludge A is dried in the sun.

Therefore, according to the sludge drying method of the first aspect of the present invention, the water in the highly hydrated sludge A can be drained by the filter cloth 12, and then when it is dried in the sun, only from the upper surface of the sludge A. In addition, since the water in the sludge can be evaporated from the side peripheral surface and the bottom surface of the filter cloth 12, there is an effect that the drying efficiency of the sludge is improved (the drying days can be shortened). According to the second aspect of the present invention, in the method for drying sludge using the filtration container 10 according to the first aspect, the filtration container 1 containing sludge is used.
Are dried in the sun while being sequentially moved from the lower shelf 21 side to the upper shelf 24 side on a plurality of shelves which are superposed and arranged at intervals vertically.

Therefore, in the sludge drying method of the present invention, the high-water content sludge filtration container 1 can be drained on the lowermost shelf 21 and the sludge-containing filtration container 1 can be separated on each of a plurality of stages. Since it can be dried, the sludge drying treatment amount per unit site area increases, and there is an effect that the site can be used effectively. Effect of the invention of claim 3 The invention of claim 3 of the present application is directed to a method for drying sludge using the filtration container 10 according to claim 1, wherein the filtration container 1 with sludge is provided.
, A plurality of shelves 31,
32, and the upper and lower shelves 31, 32
A roof plate 33 is interposed between the filters to prevent the water dripping from the sludge-filled filter container 1 placed on the upper shelf 32 from entering the sludge-filled filter container 1 placed on the lower shelf 31 while drying in the sun. I try to make it.

As described above, when the roof plate 33 is disposed between the upper and lower shelves 31 and 32, water dropped from the sludge-containing filtration container on the upper shelf enters the sludge-containing filtration container on the lower shelf. Therefore, even if each shelf is dried at a fixed position on each shelf, the dripping water does not slow down the drying speed of the lower sludge. Also, in the sludge drying method of the third aspect, since the sludge-containing filtration container 1 is dried on the plurality of shelves 31 and 32 that are vertically polymerized, it is possible to efficiently dry the sun on a small site area. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a perspective view of a filtration container used in a sludge drying method according to a first embodiment of the present application.

FIG. 2 is an explanatory diagram of a sludge drying method performed using the filtration container of FIG.

FIG. 3 is a plan view of a drying building used in a sludge drying method according to a second embodiment of the present application.

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is a side view of a drying building used in a sludge drying method according to a third embodiment of the present application.

6 is a view taken in the direction of arrows VI-VI in FIG. 5;

[Explanation of symbols]

1 is a filtration container containing sludge, 2 is a drying building, 3 is a drying building, 10
Is a filter container, 11 is a receiving basket, 12 is a filter cloth, 21 to 24 are shelves, 31 to 32 are shelves, and A is sludge.

Claims (3)

[Claims] A sludge (A) is accommodated in a filter container (10) provided with a filter cloth (12) for preventing the passage of sand and allowing the passage of water and air, and the filter container (1) containing the sludge. ) Is separated from the ground, and the water in the sludge (A) is allowed to drop naturally through the filter cloth (12). Then, the remaining moisture in the sludge (A) is removed from the upper surface and the filter cloth (12) which are open to the atmosphere. A method for drying sludge, characterized in that it is dried in the sun while evaporating from respective contact surfaces of the sludge. 2. The upper shelf (24) according to claim 1, wherein a plurality of shelves (21 to 24) in which the sludge-containing filtration containers (1) are polymerized and arranged at intervals vertically are arranged from the lower shelf (21) side. A sludge drying method characterized by drying in the sun while sequentially moving to the side. 3. The sludge-containing filter container (1) according to claim 1, wherein the sludge-containing filter container (1) is placed on a plurality of shelves (31, 32), which are vertically arranged at intervals, and between the upper and lower shelves (31, 32). The roof plate (33) is arranged on the upper shelf (32), and water dripping from the sludge-containing filtration container (1) placed on the upper shelf (32) is placed in the sludge-containing filtration container (1) placed on the lower shelf (31). A method for drying sludge, characterized in that it is dried in the sun while not entering the sludge.