JP2002292206A - Deaeration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique to effectively remove the air in the slurry pressurized by a forcibly feeding pump. SOLUTION: This deaeration apparatus 62 to be interposed between the forcibly feeding pump 12 and a filter press machine 14 is provided with an introduction port 67 for taking in the slurry supplied by the pump 12, a pipe diameter-expanded part 68 where the pipe diameter is expanded from the pump 12 side toward the machine 14 side, an air discharging part 69 having an exhausted air guiding pipe 74, a pipe diameter-reduced part 70 where the pipe diameter is reduced from the pump 12 side toward the machine 14 side and a discharge port 71 for discharging the deaerated slurry toward the machine 14. An air exhausting pipe 79 is connected to at least one end of the pipe 74 and a ventilation port 77 is formed on the surface of the part 70 side for discharging the air flowing into the port 77 to the outside through the pipe 79.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0101]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deaerator,
In particular, the present invention relates to a deaerator capable of effectively removing air in slurry supplied to a filter press.

[0092]

2. Description of the Related Art At present, in order to reduce the volume of inorganic sludge such as construction waste soil and organic sludge such as garbage and sewage sludge, these slurry-like sludges are subjected to high pressure in a filter press using a pressure pump. And a filter press type dewatering system that performs solid-liquid separation of the slurry. FIG. 6 shows an example of the configuration, in which a piston type pressure feed pump 12, a filter press machine 14, a hydraulic drive source 15 composed of a motor and a hydraulic pump, and a first check valve
16 and a second check valve 18, an air compressor 20, a slurry supply source 22, and a water storage tank 24.

The slurry supply source 22 comprises, for example, a fluidizing tank provided with a garbage cutter and a suction pump. The fluidization tank is filled with water, and the raw garbage charged is crushed to an appropriate particle size by a cutter, kneaded with water and slurried, and sent into the mud pipe 26 by a suction pump. . The slurry that has reached the cylinder 28 of the pressure pump 12 via the mud pipe 26 and the first check valve 16 is
Compressed by the pressurizing operation of the piston 30, the second check valve
It is driven at a predetermined pressure into the filter press 14 via 18.

As shown in FIG. 7, a number of filter plates 32 are arranged side by side in the filter press 14 so as to be openable and closable in the horizontal direction. Pressurized and fixed, a filter chamber 36 is formed between the filter plates 32, 32. At the center of each filter plate 32, a slurry introduction hole 38 is provided. Drainage grooves 40 are formed on both left and right sides of the filter plate, and the surface thereof is covered with a filter cloth 42. The slurry 44 driven by the pressure pump 12 travels through the slurry introduction hole 38 in the filter press 14 and diffuses into the filter chamber 36 formed between the filter plates 32.
Then, when the slurry is pressed against the surface of the filter cloth 42, moisture is filtered, and a solid component is separated. The water that has passed through the filter cloth 42 is guided to a drain port 46 provided below the filter plate 32 along the drainage groove 40, and is discharged to the outside via a water collecting pipe 48. This drainage reaches the water storage tank 24 via the drain pipe 50, and a part thereof is returned to the fluidization tank by the pump 52.
The rest will be drained.

When one driving operation by the pressure feed pump 12 is completed, the piston 30 descends and the second check valve 18 is closed, and at the same time, the first check valve 16 is opened and new slurry 44 is supplied to the cylinder. Filled in 28. When the operation of driving the slurry 44 by the pressure pump 12 is continued for a predetermined time, the inside of each filter chamber 36 of the filter press 14 is filled with the dewatered cake 54 solidified by the removal of moisture. At this stage, high-pressure air is supplied from the air compressor 20 to the slurry introduction hole 38 of the filter plate 32 from the opposite direction, and the slurry clogged in the introduction hole 38 follows a predetermined path to the slurry supply source 22 side. After being returned, the filter plate 32 is opened right and left. As a result, the filter plates 32, 32
The dewatered cake 54 accumulated in between falls off and falls under its own weight, and is guided onto a belt conveyor 58 via a discharge hopper 56.

[0086]

By using the filter press type dewatering system 60, the final dehydration pressure in the filter press machine 14 is controlled to 3.5 to 4.0 Mp by the above-mentioned pump 12.
By increasing the value to a or more, it has become possible to realize a high dewatering effect even for organic slurries, for which effective dewatering has been conventionally difficult. For example, even when a slurry containing garbage is subjected to dehydration, a dewatered cake 54 having a water content of 50% or less is obtained, and is expected to greatly contribute to volume reduction of waste. Organic slurries are composed of proteins, carbohydrates, fats and oils, fibrous, and inorganic substances, and physically form hydrophilic colloids.To destroy these hydrophilic colloids and cell membranes, dehydration of 3.5Mpa or more is required. Pressure is required.

Here, in order to effectively achieve the destruction of the hydrophilic colloid and the cell membrane in the organic slurry, water adhering to the surface and pore water are removed as much as possible before the supply to the pressure pump 12. It can be said that it is desirable to keep.
However, reducing the water content in the slurry impairs the fluidity of the slurry, making it easier to form aggregates,
A lot of air is mixed between the lumps of this slurry. As shown in FIG. 8, if a large number of air reservoirs 45 are present in the cylinder 28 of the pressure feed pump 12 or in the mud pipe 26b communicating with the filter press 14, the piston 30
Thus, even if the slurry 44 is compressed, a reverse pumping phenomenon occurs due to the air reservoir 45, and the extrusion action is absorbed. As a result, the slurry 44 that would otherwise be driven into the filter press 14 at a high pressure stagnates between the pressure pump 12 and the filter press 14,
There is a problem that the desired dehydration effect cannot be obtained.

The present invention has been devised in order to solve the above-mentioned problems of the conventional filter press type dewatering system. It is an object of the present invention to effectively remove air in slurry during pressurization by a pressure pump. It aims to provide technology that enables

[0099]

In order to achieve the above object, a deaeration device according to the present invention is a deaeration device interposed between a pressure pump and a filter press. An inlet for taking in the supplied slurry, a diameter expansion section whose diameter increases from the pressure pump side to the filter press side, an air discharge section having an exhaust guide pipe, and a direction from the pressure pump side to the filter press side. A diameter-reducing portion whose diameter is reduced, and a discharge port for sending the slurry toward the filter press machine, an exhaust pipe is connected to at least one end of the exhaust guide tube, and a surface on the diameter-reducing portion side. Is provided with a vent, and the air flowing into the vent is discharged to the outside via the exhaust pipe. The introduction port, the diameter expansion section, the air discharge section, the diameter contraction section, and the discharge port are in communication with each other. Thus, the flow rate of the slurry supplied from the pressure pump to the inlet is reduced at the diameter expanding portion where the diameter (cross-sectional area) of the flow path sharply increases.
As a result, the internal pressure of the slurry decreases, and the contained air expands and separates from the slurry. This air is again subjected to a force that is pushed backward in the diameter contracting portion where the flow path narrows, and is thus discharged to the outside from the vent of the exhaust guide pipe via the exhaust pipe.

[0010] It is desirable that the air discharge section is removably interposed between the diameter expansion section and the diameter contraction section. As a result, even if the vent is clogged with solids, it is easy to remove and clean or replace the vent with a new one.

As the air discharge unit, a unit having a first discharge unit and a second unit, each having an exhaust guide tube, is used. The air discharge unit is slidably moved between the diameter expansion unit and the diameter contraction unit. By interposing, the discharge unit interposed between the diameter expanding portion and the diameter contracting portion and the discharging unit exposed to the outside may be made alternate. In this case, when the exhaust guide pipe of one unit is clogged, the other unit can be loaded into the apparatus and the exhaust guide pipe of the unit discharged outside can be washed, Maintenance performance can be improved.

[0012] A porous ceramic filter or a hollow fiber filter may be mounted in the exhaust guide pipe of the air discharge section. As a result, it is possible to effectively prevent solid matter from entering the air guide tube, and to realize purification of air discharged to the outside.

The exhaust guide pipe of the air discharge section is formed, for example, so as to have a substantially wedge-shaped cross section. The tip of the exhaust guide pipe faces the pressure pump and the flat section faces the filter press. It is positioned and arranged, and the vent hole is formed in the plane portion. As described above, by using the exhaust guide pipe having a wedge-shaped cross section and directing the tip end thereof toward the pressure pump, the resistance at the time of passing the slurry can be reduced. In contrast,
By providing ventilation holes in the plane part with large air resistance,
The air can be efficiently guided to the vent.

An on-off valve is interposed in the exhaust pipe.
It is desirable to provide a pressure sensor for detecting the pressure on the filter press side, and further provide a control means for closing the on-off valve when the pressure on the filter press side exceeds a set value. When the pressure on the filter press increases, the flow rate of the slurry supplied from the pressure pump decreases, and the above-described effect of air expansion and release is lost, and at the same time, the slurry can flow backward toward the vent of the exhaust guide pipe. Therefore, it is effective to provide a mechanism for automatically closing the on-off valve.

[0015]

FIG. 1 is a conceptual view showing the overall structure of a filter press type dewatering system 10 according to the present invention. As in the conventional dehydration system shown in FIG. , A filter press machine 14, a hydraulic drive source 15, a first check valve 16 and a second check valve 18, an air compressor 20, a slurry supply source 22, and a water storage tank 24.

In this dewatering system 10, further,
The deaerator 62 interposed between the second check valve 18 and the filter press 14, the pressure sensor 63 interposed in the middle of the mud pipe 26b, and the exhaust system of the deaerator 62 An electromagnetic on-off valve 64 is provided, and a control unit 65 electrically connected to the pressure sensor 63 and the electromagnetic on-off valve 64 is provided. The control unit 65 includes a CPU such as a programmable controller or a personal computer, and storage means for storing a control program.

As shown in the longitudinal sectional view of FIG. 2 and the transverse sectional view of FIG. 3, the deaerator 62 includes a substantially rectangular parallelepiped housing 66.
The apparatus includes a slurry inlet 67, a diameter expansion part 68 housed in a housing 66, an air discharge part 69, a diameter contraction part 70, and a slurry discharge port 71. The inlet 67 is a pressure pump
The mud pipe 26a is connected in communication with the mud pipe 26a on the 12 side.
It has a caliber approximately equal to. Further, the discharge port 71 is
It is connected in communication with the mud feed pipe 26b of the filter press 14 and has a diameter substantially equal to that of the mud feed pipe 26b. The diameter expanding section 68 is formed integrally with the introduction port 67 and has a funnel shape whose diameter expands from the pressure pump 12 toward the filter press 14. In addition, the above-mentioned diameter contraction part
Is formed integrally with the discharge port 71,
It has a funnel shape whose diameter decreases from the side toward the filter press machine 14 side.

The air discharge section 69 is interposed between the diameter expansion section 68 and the diameter contraction section 70, and includes a substantially rectangular frame member 72,
A plurality of exhaust guide tubes 74 erected on the bottom surface 73 of the frame member 72
It has. The frame member 72 includes a first opening 75 communicating with the opening of the diameter expanding section 68 and a second opening 76 communicating with the opening of the diameter reducing section 70.
Are arranged at a predetermined interval between the first opening 75 and the second opening 76.

As shown in FIG. 3, each of the exhaust guide tubes 74 has a substantially wedge-shaped cross section. The tip 74a of the exhaust guide tube 74 faces the pressure pump 12 and the flat portion 74b faces the filter press 14. It is positioned to face. This flat part 74
b, a number of vents 77 are formed at predetermined intervals from top to bottom, and each vent 77 is provided with an exhaust guide pipe 74.
Is communicated with a hollow portion 74c penetrating the center portion. An upper end opening 74d of each exhaust guide pipe 74 is connected to a common air collecting box 78, and an exhaust pipe 79 is connected to the air collecting box 78.

The frame member 72 is slidably mounted along a guide portion 80 in a housing 66, and is provided with another air discharge portion.
It is easily interchangeable with 69. An appropriate sealing member 81 is interposed between the surface of the frame member 72 and the end surfaces of the diameter expanding portion 68 and the diameter contracting portion 70, thereby ensuring airtightness.

Hereinafter, the step of dewatering the slurry by the dewatering system 10 will be described. First, the slurry sent out from the slurry supply source 22 reaches the first check valve 16 via the mud feed pipe 26, and the cylinder of the pressure feed pump 12
28, the gas passes through the second check valve 18 and the deaerator 62 and is filled into the filter press 14. At the time when the slurry has passed through each of the filter chambers of the filter press 14, the supply of the pressurized oil from the hydraulic drive source 15 and the piston 30 of the pressure pump 12
Moves in the compression direction and drives the slurry in the cylinder 28 into the filter press 14 side. Next, at the same time when the piston 30 returns, the second check valve 18 closes, and the first check valve 16 opens to fill the cylinder 28 with the slurry. Here, when the piston 30 is driven again, the first check valve 16 closes and the second check valve 18 opens at the same time, and the slurry is pressure-fed to the filter press 14 side and passes through the deaerator 62. This effectively removes air in the slurry. By continuing the above-described slurry driving operation by the pressure pump 12, the filtrate flows out from the water collecting pipe 48 of the filter press 14 toward the drain pipe 50.

Here, the mechanism of air removal in the deaerator 62 will be described. First, when the slurry is ejected at a high pressure by driving the pressure pump 12, the slurry including the air reservoir is sent to the inlet 67 of the deaerator 62 at a flow rate of a certain value or more. Next, when the slurry reaches the enlarged-diameter portion 68 where the cross-sectional area expands more rapidly than the inlet 67, the flow velocity is rapidly reduced there and the internal pressure is reduced. As a result, the air reservoir contained in the slurry expands and is released from the slurry. Then, since the flow path is narrowed again in the diameter contracting portion 70, a force that is pushed rearward due to the contraction acts on the expanded air, so that the air is guided into the ventilation hole 77.

The air reaching the cavity 74c from the vent 77 is
It rises inside the exhaust guide pipe 74 and is collected in the air collecting box 78,
It is discharged to the outside via the exhaust pipe 79. When the dehydration process proceeds and the pressure on the filter press 14 side increases due to the increase in the cake layer, the flow rate of the slurry supplied to the diameter expansion section 68 decreases, and the effect of expanding and releasing the air reservoir decreases. At the same time, the possibility that the slurry flows back into the vent 77 increases, so the electromagnetic on-off valve 64 is closed to stop the deaeration process. Specifically, when the pressure input from the pressure sensor 63 becomes equal to or higher than the set value, a control signal is output from the control unit 65 to the electromagnetic on-off valve 64, and the exhaust pipe 79 is automatically closed.

If the above-described deaerator 62 is continuously used, solids will inevitably enter the vent 77, causing clogging. In this case, the air discharge section 69 may be extracted from the housing 66 and washed, or replaced with a new one. Alternatively, cleaning water can be supplied from the exhaust pipe 79 to backwash the inside of the exhaust guide pipe 74, and the solid matter can be discharged from the vent 77. Further, the cavity 74 of the exhaust guide tube 74
By mounting a porous ceramic filter or hollow fiber filter in c, the above-mentioned clogging can be effectively prevented and, at the same time, the air discharged to the outside can be purified.

FIGS. 4 and 5 show another example of the structure of the deaerator 62, which is characterized in that two sets of exhaust units are provided in the frame member 72 of the air discharge section 69. FIG. That is, a first exhaust unit 82 having four exhaust guide tubes 74 and a second exhaust unit 83 also having four exhaust guide tubes 74 are arranged in the frame member 72. The exhaust guide tubes 74 of the unit are connected to different air collecting boxes 78, respectively. Also, connecting pieces 84a, 84b are provided on both side faces of the frame member 72.
Is connected. A hydraulically driven cylinder 85 is mounted on the lower surface of the housing 66, and a pair of drive shafts 85 of the cylinder 85 are provided.
a and 85b are connected to the connecting pieces 84a and 84b, respectively. Therefore, by driving the drive shafts 85a and 85b of the cylinder 85 to the left and right, the air discharge unit 69 slides along the guide unit 80 of the housing 66, and switches the exhaust unit set in the housing 66. Becomes possible.

As described above, two sets of exhaust units are provided in the air discharge section 69, and the units set in the housing 66 by the cylinder drive can be replaced.
Operation efficiency and maintainability can be improved. That is, when deaeration was performed using one unit, if clogging occurred and the deaeration effect was reduced, the frame member 72 was immediately slid and replaced with the other unit. , The deaeration effect can be maintained.

For the unit taken out of the housing 66, as shown in FIG.
The cleaning water can be guided to the exhaust pipe 79 as shown in FIG. 5, and the inside of the exhaust guide pipe 74 can be backwashed. Incidentally, the exhaust pipe 79 is provided with four electromagnetic on-off valves, and when the first exhaust unit 82 is used for deaeration and the second exhaust unit 83 is backwashed at the same time, the first The second on-off valve 64a and the second on-off valve 64b are opened, and the third on-off valve 64c is opened.
And the fourth on-off valve 64d is closed. Conversely, when the second exhaust unit 83 is used for the degassing process and the first exhaust unit 82 is backwashed at the same time, the third on-off valve 64c and the fourth on-off valve 64d are opened, and the first The on-off valve 64a and the second on-off valve 64b may be closed.

[0028]

According to the deaerator of the present invention, the air contained in the slurry can be effectively removed between the pump and the filter press, so that the pressurizing operation of the pump is steadily performed on the slurry. And it can be driven into the filter press with the desired pressure.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing the overall configuration of a filter press type dewatering system incorporating a deaerator according to the present invention.

FIG. 2 is a longitudinal sectional view showing the internal structure of the deaerator.

FIG. 3 is a cross-sectional view showing the internal structure of the deaerator.

FIG. 4 is a cross-sectional view showing another configuration example of the deaerator.

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

FIG. 6 is a conceptual diagram showing an entire configuration of a conventional filter press type dewatering system.

FIG. 7 is a schematic view showing a mechanism of dehydration in a filter press.

FIG. 8 is a partial cross-sectional view showing a relationship between a slurry and an air reservoir in a conventional dehydration system.

[Explanation of symbols]

 10 Filter press type dewatering system 12 Pressure pump 14 Filter press machine 15 Hydraulic drive source 16 First check valve 18 Second check valve 20 Air compressor 22 Slurry supply source 24 Storage tank 26 Mud pipe 28 Cylinder 50 Drain pipe 62 Deaerator 63 Pressure sensor 64 Solenoid on-off valve 65 Control unit 66 Housing 67 Inlet port 68 Diameter expansion part 69 Air discharge part 70 Diameter contraction part 71 Discharge port 72 Frame member 74 Exhaust guide pipe 74a Pointed end of exhaust guide pipe 74b Exhaust Plane part of guide tube 77 Vent 79 Exhaust pipe 82 First exhaust unit 83 Second exhaust unit

Claims (6)

[Claims] 1. A deaerator interposed between a pressure pump and a filter press machine, comprising: an inlet for taking in the slurry supplied from the pressure pump; A diameter expanding portion whose diameter increases toward the filter press machine side; an air discharging portion communicating with the diameter expanding portion and having an exhaust guide tube; and communicating with the air discharging portion, from the pressure pump side to the filter press machine side A diameter contraction portion whose diameter is reduced toward the nozzle; and a discharge port that communicates with the diameter contraction portion and feeds the slurry toward the filter press. An exhaust pipe is connected to at least one end of the exhaust guide pipe. A vent is formed on the surface on the side of the diameter contracting portion, and the air flowing into the vent is discharged to the outside via the exhaust pipe. apparatus. 2. The degassing device according to claim 1, wherein the air discharge portion is detachably interposed between the diameter expansion portion and the diameter contraction portion. 3. The air discharge section includes a first discharge unit and a second unit each having an exhaust guide pipe,
The discharge unit interposed slidably between the diameter-expanding portion and the diameter-reducing portion so that the discharge unit interposed between the diameter-expanding portion and the diameter-reducing portion can be changed. Item 2. The degassing device according to Item 1. 4. The degassing device according to claim 1, wherein a porous ceramic filter or a hollow fiber filter is mounted in the exhaust guide pipe of the air discharge section. 5. The exhaust guide pipe of the air discharge section has a substantially wedge-shaped cross section, and is positioned and arranged so that a pointed end thereof faces the pressure feed pump side and a flat part faces the filter press machine side. The deaerator according to any one of claims 1 to 4, wherein the vent is formed in the flat part. 6. An on-off valve interposed in the exhaust pipe, a pressure sensor for detecting a pressure on the filter press side, and closing the on-off valve when the pressure on the filter press side exceeds a set value. The deaerator according to claim 1, further comprising a control unit.