JPH11290899A - Filter pipe type dehydrator and dehydration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an apparatus to enable inexpensive production by enhancing dehydration capacity without increasing the number of filter pipes. SOLUTION: In a filter pipe type dehydrator 10 wherein a filter pipe 20 being a filter structure and a piston 22 moved by the sludge is charged and the dehydration of sludge and the compression thereof are performed at the same time accompanied by the movement of the piston 22, a filter structure 30 is fitted to the inner peripheral surface of the cylinder 11 entirely or partially and the piston 22 is allowed to slide along the surface of the filter structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter pipe type dewatering system in which sludge introduced into a cylinder is continuously pressurized and dewatered through a filter pipe and a piston disposed inside the cylinder. It relates to a machine and a dewatering method.

[0002]

2. Description of the Related Art FIG. 3 shows an entire configuration of a sludge dewatering apparatus provided with the above filter pipe type dewatering machine. This sludge dewatering device is provided with a sludge pump 1, a flow meter 3 is interposed in a sludge supply pipe 2 extending from the sludge pump 1, and pressure gauges 4 a and 4 b are provided on the inlet side and the outlet side of the flow meter 3. Is installed. The sludge supply pipe 2 branches into two branch pipes 5a and 5b in the middle thereof.
Is arranged. The branch pipes 5a and 5b are
The filter pipe type dewatering machine 10 is connected to both ends of the cylinder 11, respectively. With the switching operation of the filling switching valve 6, the sludge is alternately injected into the cylinder 11 from one end side of the cylinder 11 to dewater the sludge. Processing is performed.

[0003] The filtrate generated by the dehydration process flows into the filter pipe 20, is collected in the filtrate collecting chamber 21, and is discharged from the filtrate discharge pipe 12 to the outside. The dehydrated dewatered cake is supplied to a cake discharge valve 1 mounted in cake discharge pipes 13a and 13b disposed at both ends of the cylinder 11.
By selectively opening 4a and 14b, the cakes are sent to the screw conveyor 15 alternately through one of the cake discharge pipes 13a and 13b, and fed into the dewatered cake hopper 16 from the screw conveyor 15.

FIGS. 4 and 5 show a conventional general configuration of the filter pipe type dehydrator 10. As shown in FIG. As shown in the figure, inside a cylinder 11, a plurality of filter pipes 20, which are filtration structures, are arranged parallel to each other along the longitudinal direction of the cylinder 11, and each filter pipe 20 is provided in a filtrate collecting chamber 21. Is in communication with Further, the interior of the cylinder 11 is divided into two chambers 23a and 23 by a piston 22.
b, and both ends of the piston 22 are elastically connected to the end plates of the cylinder 11 at one end of telescopic pipes 24a and 24b, respectively.

The other ends of the telescopic pipes 24a and 24b are connected to branch pipes 5a and 5b shown in FIG. 3, respectively. Is provided with an opening S to be thrown into the inside of the device.

Here, each of the filter pipes 20 penetrates through the inside of the piston 22 with a slight gap, and solid matter deposited on the surface of the filter pipe 20 with the movement of the piston 22 is removed. They are being shaved off.

In FIG. 4, the operation of the filter pipe type dehydrator 10 will be described with the left room 23a divided by the piston 22 as a room for filtering sludge and the right room 23b as a room for pressing concentrated sludge. explain. That is, in this state, the telescopic pipe 24a on the room 23a side
Sludge is continuously supplied into the cylinder 11 from the opening S, and the cake discharge valve 14b of the cake discharge pipe 13b on the room 23b side is opened, from which the dewatered cake is discharged to the outside.

At this time, the pressure in the room 23a gradually increases with the supply of the sludge, and the sludge supplied to the room 23a is separated from the filtrate by the filtration surface of the filter pipe 20.
The separated filtrate passes through the inside, is collected in the filtrate collecting chamber 21, and is discharged to the outside from the filtrate discharge pipe 12 shown in FIG. And the pressure on the room 23a side is the room 2
When the pressure becomes higher than the pressure on the 3b side, the piston 22 moves to the right in FIG.
As the pressure inside 1 rises, it becomes a dehydrated cake and is discharged outside through cake discharge pipe 13b. The filtration pressure is controlled by adjusting the discharge amount of the dehydrated cake at this time.

In this process, the filtration and dewatering of the sludge in the cylinder 11 and the pressing and dehydration are performed dynamically on the filtration surface of the filter pipe 20, and at the same time, the piston 22 scrapes off the solid matter adhering to the surface of the filter pipe 20. This cleaning is performed. In addition, the sludge is dewatered into the filter pipe 20 immediately after being cleaned by passing through the piston 22, whereby high-efficiency dewatering of the sludge can be performed.

When the piston 22 reaches the end of the cylinder 11, the charging switching valve 6 (see FIG. 3) is switched to perform the reverse of the above operation, and the operation is sequentially repeated, so that the continuous operation of the piston 22 is continued. The reciprocating motion is performed, whereby continuous sludge treatment can be performed.

[0011]

In the filter pipe type dehydrator having this structure, the greater the cleaning ability of the surface of the filter pipe, the greater the amount of sludge to be introduced and the greater the sludge treatment capacity. To this end, it is desirable to increase the contact length between the filter pipe and the piston, that is, to increase the number of filter pipes. On the other hand, the load on the filter pipe can be expressed by the amount of sludge in the cylinder with respect to the filtration area of the filter pipe. Therefore, if the inner diameter of the cylinder is constant, the load decreases as the number of filter pipes increases and the load decreases as the number of filter pipes decreases. This load will increase.

Therefore, it is desirable to increase the number of filter pipes as much as possible. However, increasing the number of filter pipes not only complicates the structure but also increases the number of filter pipes.
There is also a problem that the diameter of the cylinder accommodating the filter pipe inside becomes large, which leads to an increase in the size of the dehydrator.

The present invention has been made in view of the above circumstances, and has been made to improve the dewatering performance without increasing the number of filter pipes, to reduce the size of the apparatus, and to manufacture it at low cost. It is an object to provide a filter pipe type dehydrator.

[0014]

According to the present invention, there is provided a filter pipe type dehydrator having a filter pipe, which is a filtration structure, and a piston which is moved by a pressure difference between the sludge, inside a cylinder into which the sludge is charged. With the movement of the piston, in the filter pipe type dewatering machine so as to simultaneously perform dewatering of the sludge and squeezing of the sludge, as the cylinder, disposed a filtration structure on the entire inner peripheral surface or at least a part thereof,
The piston is slid along the surface of the filter structure.

Further, the dewatering method of the present invention is provided with a filter pipe, which is a filtration structure, and a piston which moves by a pressure difference between the sludge inside a cylinder into which the sludge is introduced. In a filter pipe-type sludge dewatering method in which sludge dewatering and sludge squeezing are performed simultaneously, the entire inner peripheral surface of the cylinder is provided together with a filter pipe, which is a filtration structure disposed through a piston inside the cylinder. Alternatively, a filtration structure is provided at least in part, and the piston moves in the cylinder, whereby the piston slides on the surface of the filter pipe passing through the piston, and the outer peripheral surface of the piston is By sliding the surface of the filtration structure on the inner peripheral surface of the cylinder, solid matter deposited on the surfaces of both filtration structures is removed. Filtration dehydration or squeezing and dewatering of sludge, characterized in that to proceed.

[0016] Thus, the filter structure provided on the inner peripheral surface of the cylinder has the same function as the filter surface as the filter pipe, so that the filter surface can be expanded without increasing the number of filter pipes. Thus, the load on the filtration surface can be reduced, and the sludge dewatering treatment capacity can be increased.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same members shown in FIGS. 3 to 5 are denoted by the same reference numerals and described.

As shown in FIG. 1, inside a cylinder 11, a plurality of filter pipes 20, which are filtration structures, are arranged in parallel along the longitudinal direction of the cylinder 11, and each filter pipe 20 It communicates with the chamber 21.
Further, the interior of the cylinder 11 is
The piston 22 is divided into two chambers 23a and 23b.
One end of each of telescopic pipes 24a and 24b is rigidly connected to an end plate of the cylinder 11 so as to be freely expandable and contractible.

The cylinder 11 has, on its inner peripheral surface, a filtration structure 30 having the same configuration as that of the filter pipe 20, for example.
And a filtrate flow channel 31 is formed on the outer peripheral surface of the filtration structure 30. The filtrate flow passage 31 and the filtrate collecting chamber 21 are connected to a filtrate discharge pipe 32.
And the filtrate is discharged outside the dehydrator. The inner diameter of the filtering structure 30 is set slightly larger than the outer diameter of the piston 22, and the piston 22 slides along the inner peripheral surface of the filtering structure 30.

The other ends of the telescopic pipes 24a and 24b are connected to the branch pipes 5a and 5b shown in FIG.
An opening S for introducing sludge passing through the inside into the cylinder 11 is provided.

Here, each of the filter pipes 20 penetrates through the inside of the piston 22 with a slight gap. As the piston 22 moves, solid matter deposited on the surface of the filter pipe 20 is removed. The solid matter deposited on the surface of the filtration structure 30 on which the outer peripheral surface of the cylinder 11 slides is also shaved off.

In FIG. 1, the left-side chamber 23a divided by the piston 22 is a room for filtering sludge, and the right-side room 23b is a room for compressing concentrated sludge, that is, the piston 22 is moved from the left to the right. The operation of the filter pipe type dehydrator 10 when moving will be described. That is, in this state, the telescopic pipe 24a on the room 23a side
, The cake discharge valve 14b of the cake discharge pipe 13b on the room 23b side is opened, from which the dewatered cake is discharged to the outside.

At this time, the pressure in the room 23a gradually increases with the supply of the sludge, and the sludge introduced into the room 23a is filtered by the filter structure 30 which is the inner peripheral surface of the filter pipe 20 and the cylinder 11. The filtrate is separated on the surface, and the separated filtrate is separated from the inside of the filter pipe 20 and the filtrate flow path 3.
1 and is discharged from the filtrate discharge pipe 32 to the outside.
When the pressure in the room 23a becomes higher than the pressure in the room 23b, the piston 22 moves rightward in FIG. 1, and the concentrated sludge in the room 23b Then, the cake is discharged to the outside from the cake discharge pipe 13b. The filtration pressure is controlled by adjusting the discharge amount at this time.

In this process, the filtration and dewatering of the sludge in the cylinder 11 and the compression and dehydration are dynamically performed on the filter pipe 20 and the filtration surface of the filtration structure 30 of the cylinder 11, and at the same time, the piston 22 is connected to the filter pipe 20 and the filtration structure. By shaving off solids attached to the surface of 30,
This cleaning is performed. In addition, the sludge is injected toward the filter pipe 20 and the filtration structure 30 immediately after being cleaned by passing through the piston 22, whereby high-efficiency dewatering of the sludge can be performed.

When the piston 22 reaches the end of the cylinder 11, the charging switching valve 6 (see FIG. 3) is switched to perform the reverse operation, and this operation is sequentially repeated. The reciprocating motion is performed, whereby continuous sludge treatment can be performed.

Next, the sludge treatment capacity of the filter pipe type dehydrator in this embodiment and the conventional filter pipe type dehydrator shown in FIGS. 4 and 5 will be compared.

Here, as the cylinder 11 of the filter pipe type dehydrator of this embodiment, the inner diameter D ₁ is 0.56 m,
The length L ₁ is using those 1.8 m, the filter pipe 2
0, the outer diameter d ₁ is the one of 0.1m using six to telescopic pipe 24a, the average outer diameter of 24b and 0.1m, fitting length .DELTA.l ₁ of the filtering surface and the piston 22, .DELTA.l ₁ = 0.1π × 6 + 0.56π = 3.644m Therefore, the filtration area A ₁ per unit length is 3.
A 644m ^2, volume V ₁ of the per unit ^{_{length, V 1 = (0.56 2 -7}} × 0.1 2) × π / 4 = 0.19
1 m ³ . From this, the average thickness t ₁ of the dehydrated cake is t ₁ = V ₁ / A ₁ = 0.191 / 3.644 = 0.052
m.

On the other hand, as the cylinder 11 of the conventional filter pipe type dehydrator shown in FIGS. 4 and 5, the inner diameter D ₂ is 0.
98 m and a length L ₂ of 3 m are used, and 18 filter pipes 20 having an outer diameter d ₂ of 0.1 m are used. The average outer diameter of the telescopic pipes 24 a and 24 b is set to 0.1.
Assuming m, the fitting length Δl ₂ between the filtration surface and the piston is Δl ₂ = 0.1π × 18 = 5.655 m. Therefore, the filtration area A ₂ per unit length is 5.
A 655m ^2, volume V ₂ per unit ^{_{length, V 2 = (0.98 2 -19}} × 0.1 2) × π / 4 = 0.6
05m ² . From this, the average thickness t ₂ of the dehydrated cake is t ₂ = V ₂ / A ₂ = 0.605 / 5.655 = 0.107
m.

Generally, the permeation flow rate q of water per unit area
Can be obtained by dividing the processing amount Q by the filtration area A, and is described in more detail below. q = Q / A = k (pg _c ) / μl (m / s) k: coefficient, p: pressure difference, g _c : gravity conversion coefficient, μ: viscosity, l: cake thickness Proportional to
It shows that it is inversely proportional to cake thickness and viscosity.
Here, the transmission speed per unit area of the present embodiment and the conventional example will be compared. Assuming that the transmission speeds of the present embodiment and the conventional example are q ₁ and q ₂ , q ₂ / q ₁ = l ₂ / l ₁ = 0.107 / 0.0525 = 2.
04, which is twice the transmission speed of the conventional example. This indicates that in the case of the same throughput, the present embodiment requires only one-half the filtration area of the conventional example. In the present embodiment, the sludge can be efficiently treated and the size of the apparatus can be reduced. Can be achieved. 1. In order to verify the above results, sludge concentration refined with a cationic polymer.
4% of the sewage mixed raw sludge was dewatered. Incidentally, the filtration areas of the present embodiment and the conventional example are 6.56 m ² and 1 respectively.
6.9 m ² . As a result, in the present embodiment, 6.6.
m ³ / h sludge treated cake moisture content of contrast was 76.5 percent and 78.4 percent cake moisture content to process sludge 10 m ³ / h in the conventional example. Therefore, the filtration rate is 24 kg / m ² h in the present embodiment, and 14.2 in the conventional example.
kg / m ² h, and the filtration rate of the present embodiment was 1.7 times that of the conventional example. The water content of the cake also dropped by about 2 points.

[0030]

As described above, according to the present invention,
By making the filtration structure stretched on the inner peripheral surface of the cylinder have the same function as the filtration surface as the filter pipe, the contact length between the filtration surface and the piston can be increased without increasing the number of filter pipes. In addition, the load on the filtration surface is reduced, and the sludge treatment capacity is increased, whereby the size and cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a filter pipe type dehydrator according to an embodiment of the present invention.

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

FIG. 3 is an overall configuration diagram of a sludge dewatering apparatus to which the present invention is applied.

FIG. 4 is a longitudinal sectional front view showing a conventional filter pipe type dehydrator.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

[Description of Signs] 10 Filter pipe type sludge dewatering machine 11 Cylinder 13a, 13b Cake discharge pipe 20 Filter pipe 22 Piston 23a, 23b Room 24a, 24b Telescopic pipe 30 Filtration structure 31 Filtrate flow path 32 Filtrate discharge pipe

Continued on the front page (72) Inventor Mutsuo Nakajima 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation

Claims (2)

[Claims] 1. A cylinder into which sludge is charged, a filter pipe serving as a filtration structure and a piston which moves by a pressure difference between the sludge, and dewatering of the sludge and squeezing of the sludge as the piston moves. In the filter pipe type dewatering machine, the filter structure is disposed on the entire inner peripheral surface or at least a part thereof as the cylinder, and the piston slides along the surface of the filter structure. A filter pipe type dehydrator characterized in that: 2. A cylinder into which sludge is charged, a filter pipe serving as a filtering structure and a piston moving by a pressure difference between the sludge, and dewatering of the sludge and squeezing of the sludge as the piston moves. And the filter pipe-type sludge dewatering method, wherein the filter structure is provided on the whole or at least a part of the inner circumferential surface of the cylinder together with the filter pipe, which is a filter structure disposed through the piston inside the cylinder. Is disposed, and the piston moves in the cylinder, whereby the piston slides on the surface of the filter pipe penetrating the piston, and the outer peripheral surface of the piston is formed on the inner peripheral surface of the cylinder. Sliding on the surfaces of the filtration structures removes solid matter deposited on the surfaces of the two filtration structures while filtering or dewatering sludge. Method of dehydrating sludge, characterized in that the squeezing and dewatering proceeds.