JPS6369518A - Pressurized electric permeation dehydrator - Google Patents

Abstract

PURPOSE:To obtain high dehydrating rate, by carrying out electric permeation to slurry supplied in a slurry receiving vessel between a filter plate and a pressurizing plate. CONSTITUTION:The slurry to be dehydrated is introduced to the slurry receiving vessel 1 through a supply pipe 51 opened to the side surface of the slurry receiving vessel 1. When a specified amount of slurry is introduced in the slurry receiving vessel 1, a vacuum pump 32 is started to decompress the inside of a vacuum chamber 3. Then, the pressurizing plate 7 is moved downward by pressurizing cylinders 71 to mechanically press the slurry to the filter plate 2, and a direct current voltage is impressed between electrode plates 81 and 82. Dehydration of the slurry is carried out by the vacuum suction force, mechanical pressure and electric permeating action.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a pressurized electroosmotic dewatering apparatus that uses sludge or the like generated from sewage or human waste treatment as a material to be dehydrated, and converts the sludge into a cake through a dewatering operation.

[Prior art and its problems]

As the sludge dewatering apparatus mentioned above, a vacuum dehydrating apparatus as shown in FIG. 2 is known. That is, in Figure 2, 1
1 is a slurry receiving tank, 2 is a filter plate, 3 is a vacuum chamber, and 4 is a belt type filter cloth. In addition, the slurry receiving tank 1
is a container with an open bottom that is raised and lowered by a lifting cylinder 11 relative to a filter plate 2, and a slurry supply hopper 5 is disposed above the container. A vacuum pump 32 is connected to the vacuum chamber 3 via a vacuum tank 31, and a filtrate discharge line 34 is connected to the bottom of the vacuum tank 31 via a valve 33. On the other hand, the filter cloth 4 is an endless filter cloth stretched between pulleys.
, 1 is moved on the upper surface side. In addition, 42G! Filter cloth 4
1 is a dewatered cake scraper, and 43 is a filter cloth cleaning nozzle. With this configuration, mud is poured into the slurry receiving tank l, and in this state, the vacuum pump 32 is started to reduce the pressure inside the vacuum chamber 3, so that the water contained in the slurry passes through the filter plate 2 and flows into the vacuum chamber 3. The dehydrated slurry remains on the upper surface of the filter cloth. Subsequently, the slurry receiving tank 1 is lifted to separate it from the filter cloth 4, and the filter cloth 4 is moved by the drive motor 41, so that the dehydrated material is scraped off from the filter cloth 4 by the scraper 42 and recovered as a dehydrated cake kilo. Ru. On the other hand, the filtrate that has passed through the filter plate 2 and is discharged into the vacuum chamber 3 accumulates at the bottom of the vacuum chamber 31, and from there, when the valve 33 is opened, the filtrate is discharged into the filtrate discharge line 34.
is drained out of the system through the By the way, in the above-mentioned conventional vacuum dehydration apparatus, the reduced pressure in the vacuum chamber 3 is restricted by the surrounding atmospheric pressure, and as the dehydration progresses, the filter cloth 4 becomes clogged, and as the dehydrated cake grows, the filtrate passes through. The filtration resistance increases and the dehydration effect rapidly decreases. To this end, conventional efforts have been made to improve dewatering properties by adding polymer flocculants to sludge, etc., but there is still a limit to the dewatering rate, and the dewatering cake can be dehydrated to a low enough water content that it can be disposed of by incineration. It is difficult to do so, and improvement measures are desired.

[Object of the Invention] The present invention has been made in view of the above points, and is a pressurized electroosmotic dehydration device that can obtain a high dehydration rate by incorporating electroosmosis and pressure dehydration methods into a conventional dehydration device. The purpose is to provide

[Key points of the invention]

In order to achieve the above object, the present invention includes a filter plate, a slurry receiving tank and a vacuum chamber arranged above and below the filter plate, and a pressure plate that pressurizes the slurry supplied into the slurry receiving tank toward the filter plate. and a pressurizing operation means for the same, and a direct current voltage applying means for performing an electroosmosis operation between the filter plate and the pressure plate facing the filter plate, so that in addition to reducing the pressure by vacuum, mechanical A high dehydration rate can be obtained by applying high pressure and electroosmosis.

[Embodiments of the invention]

FIG. 1 shows the configuration of a pressurized electroosmotic dehydrator according to an embodiment of the present invention, and the same members as in FIG. 2 are given the same reference numerals. That is, according to the present invention, inside the slurry receiving tank 1, a pressure plate 7 is provided which covers the inner surface area of the tank and is driven and operated by a hydraulic or pneumatic pressure cylinder 71. Note that 72 is a sealing material provided around the periphery of the pressure plate 7. Furthermore, electrode plates 81 and 82 are arranged on the inner surface side of the pressure plate 7 and the back side of the filter plate 2 opposite thereto,
A DC power supply 83 is connected between the electrode plates 81 and 82 to provide voltage application means 8 for electroosmosis. Note that the electrode plate 82 is formed as a perforated electrode plate. Next, the dewatering operation of the slurry with the above configuration will be explained. First, slurry, which is a material to be dehydrated, is introduced into the slurry receiving tank 1 through a supply pipe 51 that opens on the side surface of the slurry receiving tank 1 . At this time, the pressure plate 7 is waiting at the raised position. When a predetermined amount of slurry is introduced into the slurry receiving tank l, the vacuum pump 32 is then started to reduce the pressure in the vacuum chamber 3, and the pressure plate 7 is moved downward by operating the pressure cylinder 71. The slurry is mechanically pressurized toward the filter plate 2, and then the electrode plate 81
A DC voltage is applied between and 82. As a result, the water contained in the slurry moves toward the cathode side, that is, the electrode plate 82 on the iii overplate side, due to the vacuum suction force 1, the vacuum and pressure dehydration effect due to the mechanical pressure force, and the electroosmosis effect. The slurry passes through the filter cloth 4 and the filter plate 2, and is filtered and discharged into the vacuum chamber 3. Moreover, as the volume of the slurry decreases with the progress of this dehydration operation, the electrode plate 8
As the distance between 1 and 82 gradually narrows, the electric field strength between the electrode plates increases, and the electroosmotic effect further increases.
In this way, sludge and the like that are difficult to dewater can be directly dehydrated to a sufficiently low water content. Note that the discharge of the filtrate dehydrated and separated from the slurry and the collection of the dehydrated cake are performed in the same manner as described in FIG.

【Effect of the invention】

As described above, according to the present invention, there are provided a filter plate, a slurry receiving tank and a vacuum chamber disposed above and below the filter plate, and a pressure plate that pressurizes the slurry supplied into the slurry receiving tank toward the filter plate. Since it is configured to include a pressurizing operation means and a DC voltage applying means for performing electroosmotic operation between the filter plate and the opposing pressure plate, direct dehydration is difficult with conventional dehydrating equipment. It is possible to provide a dewatering device with excellent performance that can dehydrate even sludge and the like to a sufficiently low water content.

[Brief explanation of the drawing]

FIG. 1 is a structural layout diagram of a pressurized electroosmotic dehydrator according to an embodiment of the present invention, and FIG. 2 is a structural layout diagram of a conventional vacuum dehydrator. In each figure, 1 Nislari receiver, 2
: filter plate, 3: vacuum chamber, 7: pressure plate, 71: pressure cylinder, 8: DC voltage application means, 81.82 = electrode plate, 83
:DC power supply. Figure 1

Claims (1)

[Claims] A filter plate, a slurry receiving tank and a vacuum chamber disposed above and below the filter plate, a pressurizing plate and its pressurizing operation means for pressurizing the slurry supplied into the slurry receiving tank toward the filter plate, and the filter plate. 1. A pressurized electroosmotic dehydration apparatus comprising: a DC voltage applying means for performing an electroosmotic operation between the pressurizing plate and the pressurizing plate facing the pressurizing plate.