JP2781519B2 - Sludge sun drying floor drainage method and sludge sun drying equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drainage method for drying sludge having a very high water content on a filtration layer by sunlight and to a solar drying apparatus for sludge using this method.

[0002]

2. Description of the Related Art Sludge is muddy water containing 90% or more of water generated when biologically treating sewage. Most of the water is in microbial tissues, and it is not easy to separate water. Absent. Therefore, water separation of sludge must be performed mechanically by a centrifuge or the like, but strong centrifugal force must be applied to destroy microbial tissue, and equipment and power costs are enormous, Further, the bearing portion is easily damaged by harmful substances contained in the sludge, and the maintenance cost is enormous. Therefore, such mechanical water separation is hardly performed.

[0003] A typical conventional method is to construct a sun-dried bed in the form of a pool with a slope, provide a settling filtration layer consisting of a crushed stone layer and a sand layer on the bottom of the bed, and put sludge on the bed. It is sprayed, water is allowed to permeate the filtration layer over time, and a centralized drain is provided at an appropriate place to drain water, and the remaining sludge is dried in the sun.

[0004]

Since the water content of the sludge on the filtration layer is in the microbial tissue, it takes time to filter the water content, and the separated water becomes muddy and the flow is insufficient. However, there is a problem that a kind of clogging phenomenon in which a biological reaction occurs at the bottom surface of the floor and mud stays or the like occurs, and the separated water is not discharged. This prolongs the solar drying period of the sludge, and if there is rainfall during the drying, the sludge will be diluted, and it will take longer to dry, reducing the processing capacity, requiring a processing unit with a large floor area, etc. Economic problems arise.

An object of the present invention is to provide a method of installing a drain pipe in which separated water from sludge quickly penetrates a filtration layer, and the permeated water is drained smoothly without stagnating at the bottom of the bed of the filtration layer. An object of the present invention is to provide a sludge solar drying apparatus using a construction method.

[0006]

According to the present invention, an underdrain drain pipe is provided in a sediment filtration layer on a solar drying bed for sludge, which is arranged in a substantially parallel manner with a gentle slope, and the underdrain drain pipe is connected to a central drain. A method for draining a sun-dried sludge floor, characterized by vertically inserting a plurality of gas vent pipes having substantially the same configuration as the culvert drain pipe from the settling filtration layer to above the sludge layer to degas.

Further, according to the present invention, the culvert drainage pipe and the gas vent pipe are divided by a plurality of continuous slits which are continuous along the axis of the pipe, and a partition plate extending in the circumferential direction. It is characterized by being a synthetic resin extruded product having a continuous space chamber and a projection provided outside the space chamber.

In the present invention, the culvert drainage pipe and the gas vent pipe may be formed such that the cross section perpendicular to the axis is formed in a horizontal S-shape, and each has two elongated openings and two space chambers connected to the openings. It is characterized in that two projections are formed in the vicinity of the opening.

In the present invention, the culvert drainage pipe and the gas vent pipe may be formed in the shape of a cloverleaf in cross section perpendicular to the axis, and each of the slit may have three elongated openings and three space chambers connected to the openings. Is characterized in that two projections are formed in the vicinity of.

Further, according to the present invention, the culvert drainage pipe and the gas vent pipe are constituted by a bundled culvert drainage pipe in which a plurality of the culvert drainage pipes of the second or third aspect are bound so as to have a substantially circular outer shape. It is characterized by the following.

[0011] In the present invention, the sediment filtration layer on the sun-dried bed of sludge comprises a crushed stone layer, a culvert drain pipe arranged in parallel with the crushed stone layer on the bottom surface, and a sand layer on the crushed stone layer. The culvert drain pipe is connected to the central drain with a gentle slope, and a plurality of gas vent pipes with almost the same configuration as the culvert drain pipe are inserted vertically from the sedimentation filtration layer to the upper part of the sludge layer. Is a sludge solar drying apparatus.

[0012]

According to the present invention, the mud separated from the sludge is filtered by the sedimentation filtration layer, enters the culvert drainage pipe, and is discharged from the central drain. The sludge also causes a biological reaction during water separation, and the generated gas accumulates in the sludge layer and the filtration layer. This gas is hard to escape due to the viscosity of the sludge, and this gas hinders the passage of water. Therefore, a gas vent tube is provided in the vertical direction from the filtration layer to the upper part of the sludge layer, and this gas is discharged into the atmosphere.

[0013] The culvert drain has an elongated opening along its axis, through which the permeated water separated and filtered from the sludge flows into the space chamber and into the central drain without clogging. . Since the gas exhaust pipe has almost the same configuration as the culvert drain pipe, only water and gas enter during the gas exhaust pipe,
Gases are easily released into the atmosphere through water.

Examples of the cross section of the culvert drainage pipe and the gas vent pipe at right angles to the axis include a horizontal S-shaped two-passage and a cloverleaf three-passage.

As the culvert drainage pipe and the gas vent pipe, any one of the above-described structures is used, but a plurality of culvert drainage pipes may be bundled so that the outer shape is substantially circular.

[0016]

The present invention will be described more specifically with reference to the following examples.

FIG. 1 is a plan view of a solar drying floor of a solar sludge drying apparatus 1 according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along a section line II-II. Floor plate 3 of this device 1
Is made of concrete, for example. On this floor plate 3, culvert drain pipes 4 are arranged in parallel. The floor plate 3 has a filtration layer 7 composed of a crushed stone layer 5 and a sand layer 6, and further has a sludge layer 8 on which sludge is sprayed. The muddy water separated by the sludge layer 8 is filtered by the filtration layer 7, and the moisture enters the culvert drainage pipe 4 on the floor plate 3, flows through the culvert drainage pipe 4 with a gentle gradient, flows into the central drainage ditch 2, and is drained. You. Also, at a certain interval, a gas vent tube 9 having substantially the same configuration as the culvert drainage tube is provided with a filter layer 7.
From the top to the upper part of the sludge layer 8. The degassing tube 9 is necessary to prevent gas from staying in sludge that becomes clumpy as it dries. Sludge is guided to the present apparatus 11 by the pipe 10 and is sprayed.

FIG. 3 shows a culvert drain pipe 4 used in the present invention.
It is a perspective view of an example. The culvert drain pipe 4a in this example has a horizontal S-shape, and has two openings 4 along the axis.
2a, 42b, and 2 connected to the openings 42a, 42b.
Two space chambers 43a, 43b and two space sections 43a, 4
3b, and four C-shaped reinforcing projections 4 provided on the outer surface for reinforcing against external pressure
4 and four projections 45 provided near the openings 42a and 42b to bend the passage leading to the openings 42a and 42b to prevent intrusion of substances other than water. It is a molded product. The muddy water separated from the sludge layer 8 is filtered by the filtration layer 7 and becomes permeated water, enters the left space chamber 43b from the upper opening 42b of the culvert drainage pipe 4a, and flows down to the central drainage pipe 2 by a gradient. Further, the permeated water collected on the bottom surface 3 flows from the lower opening 42a to the right space chamber 4
The space 4 formed by the C-shaped convex portion 44 and the floor 3 provided in the lower surface of the culvert drain pipe 4a.
6 and flow down to the central drain 2. Culvert drain 4a
Is resistant to external pressure by a reinforcing projection 44 provided outside, and the openings 42a and 42b are narrow but are elongated and open along the axis, so that they are hard to be embedded. Solids are in the space chambers 43a, 43
b, and the space chambers 43a and 43b are not closed. The size of the culvert drain pipe 4a is, for example, 25 mm in width (horizontal direction in FIG. 3) and 24 in height (vertical direction in FIG. 3).
mm.

The structure of the gas vent tube 9 is substantially the same as that shown in FIG. 3, and the gas is passed through the openings 42a and 42b.
Enters the space chambers 43a and 43b from above, and rises to be discharged into the atmosphere. Since only water accumulates in the space chambers 43a and 43b, gas can easily escape.

FIG. 4 is a sectional view of another culvert drainage pipe 4b used in the present invention. The configuration of the culvert drain pipe 4b is similar to that of the culvert drain pipe 4a in FIG. 3, and the same members are denoted by the same reference numerals and description thereof will be omitted. It should be noted that four flat plate-like protrusions 44b are provided on the outer surface.

FIG. 5 is a sectional view of still another culvert drainage pipe 4c used in the present invention. It should be noted that the culvert drain pipe 4c is formed in the shape of a clover leaf, and has three openings 42a to 42c and 43a to 43c, respectively. Also, a reinforcing projection 4 provided on the outer surface.
4 are C-shaped, and three protrusions 45 are provided near the openings 42a to 42c. These functions are the same as those of the culvert drain pipe 4a described with reference to FIG.

The culvert drainage pipe 4 may have another shape, and the number of openings and space chambers may be four or more. The shape and number of the reinforcing projections and the number of projections are not particularly limited.

The culvert drain pipe 4 may be a single pipe as shown in FIGS. 3 to 5, but a plurality of such culvert drain pipes 4a, 4b or 4c may be used so that the outer shape is substantially circular. The united culvert drainage pipe 20 that has been united may be used. FIG. 6 is a perspective view of a bundled culvert drainage pipe 20a obtained by binding the culvert drainage pipe 4a of FIG. The binding culvert drainage pipe 20a is bound by a binding member 21 such as a synthetic resin band at intervals of, for example, 1 m. FIG. 7 is a cross-sectional view of a bundled culvert drainage pipe 20a obtained by binding a horizontal S-shaped culvert drainage pipe 4a, and FIG. 8 is a collective culvert drainage pipe 20c obtained by binding a clover leaf-shaped culvert drainage pipe 4c.
FIG. The size of the collective culvert drainage pipe 20 is, for example, a single culvert drainage pipe 4a having a width × height = 25 × 20.
When this unity is performed, a cylindrical collecting culvert drain pipe 20a having an outer diameter of 75 mm is obtained. Similarly, if 120 pieces are bound, the outer diameter becomes 30
A 0 mm cylindrical collecting culvert drain pipe 20a is obtained.

FIG. 9 is a cross-sectional view of a solar sludge drying apparatus 11 according to another embodiment of the present invention. It should be noted that sludge filtration layers 7 are provided on both sides of the central drain 2.

When the sludge is dried using the apparatus of the present invention,
Within a few days, cracks are formed on the surface of the sludge layer 8 around the gas vent tube 9, and the cracks gradually develop and reach the entire surface of the sludge layer 8. After cracking, even if there is rainfall, rainwater is discharged from the crack through the filtration layer 7. However, if there is rainfall before cracking, the sludge is diluted by the rainwater, so that cracking occurs. Early formation is required.

In the case where the underdrain drainage pipe of the present invention is used and the case where it is not used, the number of days required for crack generation is about 1/2 to 1/3. If the gas vent tube 9 is provided, the gas vent tube 9 becomes a nucleus to further accelerate the crack generation. The above numerical values are for the case where the gas vent tube 9 is provided. In addition,
The dried sludge has a size of about 10 cm square and can be easily separated from the sand layer 5.

[0027]

As described above, according to the present invention, culvert drainage pipes are arranged in parallel at a gentle gradient on the bottom of the floor of the solar drying apparatus for sludge, and are arranged horizontally, so that water in the sludge is separated.
It is filtered by a filtration layer provided below the sludge layer and discharged from the central drainage pipe through the culvert drainage pipe. Further, since the gas vent tube is provided vertically from the filtration layer to above the sludge layer, gas does not accumulate in the sludge. The culvert drain pipe has a plurality of openings elongated along the axis, a plurality of space chambers connected to the openings, and a projection protruding to the outside for reinforcement. No space other than water enters the room. As a result, the separated water in the sludge is quickly discharged without staying at the bottom of the drying bed. Also, for the same reason, only water and gas enter the gas vent tube, and the gas passes through the water and is discharged to the atmosphere. Outgassing also becomes a core of crack generation as the sludge dries. These can accelerate the generation of cracks on the sludge surface and reduce the effects of rainfall during drying.

[Brief description of the drawings]

FIG. 1 is a plan view of a solar drying bed of a solar sludge drying apparatus 1 according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along section line II-II in FIG.

FIG. 3 is a sectional view of an example of a culvert drainage pipe 4a used in the present invention.

FIG. 4 is a cross-sectional view of another example of a culvert drain pipe 4b.

FIG. 5 is a sectional view of a culvert drainage pipe 4c of still another example.

FIG. 6 shows a bundled culvert drainage pipe 20 obtained by binding the culvert drainage pipe 4a.
It is a perspective view of a.

FIG. 7 shows a bundled culvert drainage pipe 20 obtained by binding the culvert drainage pipe 4a.
It is sectional drawing of a.

FIG. 8 shows a bundled culvert drainage pipe 20 obtained by binding the culvert drainage pipe 4c.
It is sectional drawing of c.

FIG. 9 is a solar sludge drying apparatus 11 according to another embodiment of the present invention.
FIG.

[Explanation of symbols]

 1,11 Sludge solar drying device 2 Centralized drain ditch 3 Solar drying floor 4,4a, 4b, 4c Underdrain drainpipe 5 Crushed stone layer 6 Sand layer 7 Sedimentation filtration layer 8 Sludge layer 9 Gas exhaust pipe 20,20a, 20b, 20c Bundling culvert drainage pipe 42a, 42b, 42c Slender opening 43a, 43b, 43c Space chamber 44, 44a Reinforcement convex part 45 Projection

Claims (6)

(57) [Claims] 1. A culvert drainage pipe is provided in a sediment filtration layer on a solar drying bed of sludge in a gentle gradient substantially in parallel, and the culvert drainage pipe is connected to a central drainage ditch. A method for draining a sun-dried sludge floor, comprising inserting a plurality of gas vent pipes having substantially the same configuration as the culvert drain pipe in the vertical direction until the gas is released. 2. A space in which the culvert drainage pipe and the gas vent pipe are separated by a plurality of continuous elongated openings along the axis of the pipe and a partition plate extending in a circumferential direction, and each of the spaces is connected to each of the openings. 2. The method for draining a sun-dried sludge floor according to claim 1, comprising a chamber, and a convex portion provided outside the space chamber, wherein the extruded product is made of a synthetic resin. 3. The cross section of the culvert drainage pipe and the gas vent pipe at right angles to the axis is formed in a horizontal S-shape, and there are two elongated openings and two space chambers connected to the openings. 3. The structure according to claim 2, wherein two projections are formed in the vicinity.
The drainage method of the sun drying floor of the sludge described. 4. The culvert drainage pipe and the gas vent pipe are formed in the shape of a cloverleaf in cross section perpendicular to the axis, and have three elongated openings and three space chambers connected to the openings. 3. The method for draining a sun-dried sludge floor according to claim 2, wherein two projections are formed. 5. The culvert drainage pipe and the gas vent pipe are constituted by a united culvert drainage pipe obtained by binding a plurality of the culvert drainage pipes of claim 2 or 3 so as to have a substantially circular outer shape. The method for draining a sun-dried sludge floor according to claim 1. 6. A sediment filtration layer on a sundry bed of sludge comprises a crushed stone layer, a culvert drain pipe arranged in parallel in the crushed stone layer on the bottom surface, and a sand layer on the crushed stone layer. Sludge characterized by a plurality of gas vent pipes, which have almost the same structure as the culvert drain pipe, are inserted vertically from the settling filter layer to the upper part of the sludge layer with a gentle slope. Solar drying equipment.