JP2014193437A - Sludge dehydration machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge dehydration machine which promotes filtration under an appropriate internal pressure by adjusting the opening ratio arbitrarily according to the type and properties of coagulated sludge in the first half of a dehydration step and realizes an optimal dehydration condition by increasing the compaction power in the latter half of the dehydration step.SOLUTION: In a sludge dehydration machine, a screen 2 is arranged around a screw blade, and a filtration chamber along the axial-center direction of the screw blade is formed in the screen. Screen segments 21 and 22 on the first-half side of the filtration chamber carry out filtration, and the screen segments 23 and 24 on the latter-half side of the filtration chamber carry out dehydration. The screen segments 21 and 22 on the first-half side of the filtration chamber are opened in the form of a slit, and the screen segments 23 and 24 on the latter-half side of the filtration chamber are opened in the form of holes.

Description

  The present invention relates to a sludge dehydrator, which is a technique for improving dewatering efficiency.

  Conventionally, in a screw press type dehydrator used as a sludge dehydrator in this type of technology, the free water that is the liquid phase in the sludge is filtered in the first half of the dewatering process, and in the latter half of the dewatering process. Increasing the compaction force for dehydration and discharging the contained water contained in the solid phase.

  For this reason, for example, there is one described in Patent Document 1, which is configured as shown in FIG. In FIG. 4, the screw press type dehydrator supports a screen 52 by a main body 51 and is inserted into the screen 52 in the axial direction to form screw blades and screw shafts around the axis of the screw shaft. A back pressure plate is disposed on the sludge discharge side of the main body 51 so as to face the opening of the screen 52.

  The screen 52 is divided into a plurality of segments in the axial direction, and is composed of a plurality of segments divided vertically. The screen (A1) 52A in the upper screen region corresponding to the upper filter chamber in the sludge supply side region, and the lower filter chamber A corresponding screen lower area screen (A2) 52B, a screen upper area screen (B1) 52C corresponding to the upper area of the central filter chamber, a screen lower area screen (B2) 52D corresponding to the lower area of the filter chamber, It consists of a screen (C1) 52E in the upper screen area corresponding to the upper part of the filter chamber in the sludge discharge side area, and a screen (C2) 52F in the lower screen area corresponding to the lower part of the filter chamber.

  When punching metal is applied to the screen 52, the adjustment of the filterability of the screen 52 is realized using the size of the hole and the aperture ratio as elements. For example, the screen (A1) 52A has a hole diameter φ1.5 mm × pitch P2.25 mm and an aperture ratio of 40.3%, and the screen (B1) 52C has a hole diameter φ1.0 mm × pitch P1.5 mm and an aperture ratio of 40.3%. Yes, the screen (C1) 52E has a hole diameter of φ0.5 mm × pitch P of 1.0 mm and an aperture ratio of 22.7%, and the screen (A2) 52B has a hole diameter of φ1.5 mm × pitch P of 3.0 mm and an aperture ratio of 22.7%. Yes, the screen (B2) 52D has a hole diameter φ1.0 mm × pitch P 2.0 mm and an aperture ratio of 22.7%, and the screen (C2) 52F has a hole diameter φ0.5 mm × pitch P 1.0 mm and an aperture ratio 22.7%. is there.

JP 2010-137114 A

  As described above, in Patent Document 1, in the filtration zone in the first half of the dehydration process, the pore diameter is set to φ1.5 mm in order to filter the free water that is the liquid phase in the sludge, and in the dehydration zone in the second half of the dehydration process, the consolidation force In order to dehydrate the inclusion water contained in the solid phase by increasing the pore diameter, the hole diameter is set to φ0.5 mm to improve the dehydration efficiency.

  However, depending on the type and properties of the coagulated sludge, the pore diameter for achieving the optimal dewatering state in the filtration zone in the first half of the dewatering process may be 1 mm or less. If the hole diameter is φ1.5 mm, the solid phase leaks from the screen. Since the amount to be discharged increases and the filling amount cannot be secured, there is a problem that the internal pressure does not increase and the filtration is not promoted.

  For this reason, in order to implement | achieve the optimal dehydration state for the kind and property of the aggregation sludge used as object, it is calculated | required to set a hole diameter to arbitrary magnitude | sizes. However, there is a technical limit in reducing punching holes, and the aperture ratio is reduced, resulting in insufficient drainage in the filtration zone. Further, as the hole for punching becomes smaller, the fiber content in the sludge becomes more likely to block the hole, and the dewaterability may be significantly deteriorated. In addition, punching metal is a standard product, and the hole diameter, pitch, etc. are determined for each manufacturer, and it is not easy to obtain punching metal with the hole diameter necessary to achieve the optimal dewatering condition. The pore sizes that can be selected to obtain are limited.

  The present invention solves the above-mentioned problem, realizes an arbitrary opening ratio according to the type and properties of the coagulated sludge in the first half of the dewatering process, promotes filtration at an appropriate internal pressure, and in the second half of the dewatering process. An object of the present invention is to provide a sludge dewatering machine capable of realizing an optimal dewatering state by increasing the consolidation force.

  In order to solve the above problems, the sludge dewatering machine of the present invention has a screen disposed around the screw blades to form a filter chamber along the axial direction of the screw blades in the screen. The sludge dehydrator is responsible for filtration and the screen on the latter half of the filter chamber is responsible for dehydration. The screen on the first half of the filter chamber opens in a slit shape, and the screen on the second half of the filter chamber opens in the shape of a hole. It is characterized by being opened.

  In the sludge dewatering machine of the present invention, the screen on the first half of the filter chamber has a plurality of wedge wires, and has screen eyes 201 opened in a slit shape between the wedge wires, and the screen on the second half of the filter chamber is punched. It is characterized by having a mesh made of metal and opening in a hole shape.

  The sludge dewatering machine of the present invention has a screen arranged around the screw blades to form a filter chamber along the axial direction of the screw blades in the screen, and the screen on the first half side of the filter chamber is responsible for the filtering action. The screen on the side is a sludge dehydrator responsible for dehydration. The screen on the first half of the filter chamber is open in the form of a slit on the upper side, and the screen on the latter side of the filter chamber is opened in the shape of a hole. It is characterized by opening in a hole shape.

  In the sludge dehydrator of the present invention, the screen on the first half side of the filter chamber has a screen 201 having an upper side made of a plurality of wedge wires and slits between the wedge wires, and a lower side made of punching metal. The screen in the latter half of the filter chamber is characterized by having a mesh made of punching metal and opening in a hole shape.

  In the sludge dewatering machine of the present invention, the screw provided with screw blades around the shaft center is arranged up and down, and the screen on the first half side of the filter chamber corresponds to the upper screw on the upper side and the lower screw on the lower side. It is characterized by.

  In the sludge dehydrator according to the present invention, the screen on the first half of the filter chamber supports the outside of the plurality of wedge wires with the bar material 203.

  As described above, according to the present invention, the screen on the first half side of the filter chamber responsible for the filtering action is opened in a slit shape, so that an arbitrary opening ratio corresponding to the type and property of the coagulated sludge can be realized and an appropriate internal Filtration can be accelerated by pressure.

  That is, in the case of opening in the shape of a hole, there is always a member constituting the screen around the hole of the round hole or the square hole, but by opening in a slit shape, the member constituting the screen is in the slit direction. It does not exist, and the slits are linear, so if the hole diameter is equal to the opening of the slit, the resistance is reduced compared to the hole by opening it in the slit shape. Water can easily escape. In addition, it is possible to set the size of the opening sufficiently small relative to the size of the solid phase lump of the coagulated sludge while ensuring the necessary opening ratio, and promote filtration with an appropriate internal pressure. Is possible.

  Since the screen is formed with a plurality of wedge wires, the size of the slit-shaped openings formed between the wedge wires can be arbitrarily set, and the screen on the latter half side of the filter chamber is made of punching metal. Since the mesh is open in the form of holes, the compaction force can be increased in the latter half of the dehydration process. Therefore, an optimal dehydration state can be realized by combining the screen on the first half of the filter chamber opened in a slit shape and the screen on the second half of the filter chamber opened in a hole shape.

The schematic diagram which shows the screw press type dehydrator in embodiment of this invention The figure which shows the cross section of the screen of the wedge wire The schematic diagram which shows the screw press type | mold dehydrator in other embodiment of this invention. Schematic diagram showing a conventional screw press dehydrator

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the basic structure of the screw press type dehydrator according to the present embodiment is based on a known technique, and is roughly as follows.

  A screw press type dehydrator as a sludge dehydrator supports a screen 2 by a main body 1 and is inserted into the screen 2 in the axial direction around a screw shaft (not shown) and the axis of the screw shaft. Screw blades (not shown) are formed, a filter chamber is provided in the screen 2 along the axial direction of the screw blades, and a back pressure plate is disposed on the sludge discharge side of the main body 1 facing the opening of the screen 2. ing.

  In this embodiment, the screen 2 is composed of segments divided into a plurality of axial directions. The screen segments 21 and 22 on the first half of the filtration chamber are responsible for the filtering action, and the screen segments 23 and 24 on the second half of the filtration chamber are the dehydrating action. Is responsible.

  Both of the screen segments 21 and 22 on the first half of the filter chamber are made of a plurality of wedge wires. As shown in FIG. 2, a screen mesh 201 having slits is formed between the wedge wires 200, and the wedge wire 200 having a thickness of 1-2 mm, for example, is used. The slit width of the eye 201 is set to 0.2-0.6 mm, and the aperture ratio is the same as the conventional one.

  The wedge wire 200 has an isosceles triangle cross section, and the apex angle portion is supported by a bar 203 arranged in a direction orthogonal to the wedge wire 200, and the screen eyes 201 between the wedge wires 200 are spaced at regular intervals. Is retained.

With this configuration, the water coming out of the screen eyes 201 flows out quickly by passing through the bar 202 before it becomes a large water droplet, so that drainage is improved.
The screen segments 23 and 24 on the latter half side of the filter chamber have a mesh made of punching metal and opened in a hole shape. In the present embodiment, the screen segment 23 has, for example, a hole diameter of 0.5 mm × pitch P of 1.0 mm, and the screen segment 24 has a smaller pitch than the screen segment 23 and has the same aperture ratio. Since the screen segments 23 and 24 are formed by a plurality of wedge wires 200, the size of the slit-shaped openings formed between the wedge wires 200 can be arbitrarily set.

  The punching metal has a larger aperture ratio as the number of holes is increased by narrowing the pitch if the hole diameter is constant, and the aperture ratio is increased as the hole diameter is increased if the pitch is fixed. However, punching metal always has a member constituting the screen 2 around the hole. On the other hand, by opening the slits in a slit shape, there is no member constituting the screen 2 in the slit direction, and the screen eyes 201 are linear, so that resistance is less than that of the holes and free water is easily drained. Become.

  Further, in the case where the hole diameter is equal to the opening of the slit, the opening ratio is increased by opening the slit, so that the screen segments 21 and 22 on the first half side of the filter chamber have the necessary openings. While ensuring the rate, it becomes possible to set the size of the openings sufficiently small with respect to the size of the solid phase lump of the coagulated sludge, and it is possible to promote the filtration with an appropriate internal pressure.

  With the above-described configuration, the dewatered sludge thrown into the screen 2 is conveyed to the sludge discharge side by the rotation of the screw shaft and screw blades while being filtered by the screen 2. The sludge is dehydrated by the action of the compaction force due to the reduction of the filter chamber volume and the back pressure by the back pressure plate, and is discharged to the outside of the screen 2 through the opening on the sludge discharge side.

  During this time, the screen segments 21 and 22 on the first half of the filter chamber responsible for the filtration function open in a slit shape, so that the required opening ratio is ensured and the size of the solid phase lump of the coagulated sludge is confirmed. It is possible to set the size of the opening sufficiently small, and it is possible to realize an arbitrary opening ratio according to the type and property of the coagulated sludge and promote filtration with an appropriate internal pressure.

Since the screen segments 23 and 24 on the latter half side of the filter chamber are made of punching metal and have a mesh opening in the shape of holes, the compaction force can be increased in the latter half of the dehydration process.
Thus, by combining the screen segments 21 and 22 on the first half of the filter chamber opened in a slit shape with the screen segments 23 and 24 on the second half of the filter chamber opened in a hole shape, the moisture in the sludge is very Filtration can be promoted in the first half of the filter chamber, which has many properties, and in the latter half of the filter chamber responsible for dewatering, sludge can be prevented from leaking and efficiently dehydrated by its compaction force. The optimal dewatering state can be realized.

  In addition, by implementing an operation method in which the pressure for supplying sludge is intentionally set higher than before, it is possible to further promote filtration in the first half of the filter chamber where the moisture content in the sludge is very high. The sludge is continuously supplied to the latter half of the filter chamber that is responsible for dehydration while maintaining the internal pressure, so that the consolidation force in the latter half of the filter chamber is further increased, and as a result, the dehydration effect is increased.

  The ratio of the area of the screen segments 21 and 22 composed of the wedge wire 200 to the total area of the screen 2 is varied within a range of 1/12 to 1/2 according to the type, properties, concentration, etc. of sludge that differs for each treatment facility. The ratio of the screen segments 21 and 22 made of the wedge wire 200 is increased for sludge with a lot of moisture, and the ratio of the screen segments 21 and 22 made of the wedge wire 200 is made for sludge with a little moisture. Efficient dehydration can be realized by reducing the value of.

  As shown in FIG. 3, the screen segments 21, 22, and 25 made of the wedge wire 200 are arranged on the first half of the filter chamber, and the openings of the screen eyes 201 of the screen segments 25 are changed to the screen eyes 201 of the screen segments 21 and 22. It is possible to make the opening smaller than the mesh opening, and a screen segment 24 made of punching metal is disposed on the latter half side of the filter chamber.

  In particular, in a large model, the liquid phase concentrates in the upper part of the machine, and the solid phase concentrates in the lower part. Therefore, in the configuration shown in FIG. By having a screen 201 that is made of wedge wire 200 and slits between the wedge wires 200, and that the lower side is made of punching metal and has a mesh that is opened in a hole shape, Water drainage on the side is promoted, and the sludge inside becomes a uniform concentration, and dehydration is stabilized.

  As another embodiment, it is also possible to arrange screws on the main body 1 up and down. In this case, the screen segments 21 and 22 in the first half of the filter chamber correspond to the screws in the upper screen segment 21. The lower screen segment 22 corresponds to the lower screw.

DESCRIPTION OF SYMBOLS 1 Main body 2 Screen 21, 22, 25 Screen segment which consists of wedge wires 23, 24 Screen segment which consists of punching metals 200 Wedge wire 201 Screen eyes 202 Bar material

Claims (6)

A screen is arranged around the screw blades to form a filter chamber along the axial direction of the screw blades in the screen. The screen on the first half of the filter chamber is responsible for filtration, and the screen on the latter half of the filter chamber is responsible for dehydration. A sludge dewatering machine,
A sludge dewatering machine characterized in that the screen on the first half of the filter chamber is opened in a slit shape, and the screen on the second half of the filter chamber is opened in a hole shape.   The screen in the first half of the filter chamber has a plurality of wedge wires, and has a screen opening in the shape of a slit between the wedge wires. The screen in the second half of the filter chamber is made of punching metal and has openings in the form of holes. The sludge dewatering machine according to claim 1, wherein the sludge dewatering machine has a mesh. A screen is arranged around the screw blades to form a filter chamber along the axial direction of the screw blades in the screen. The screen on the first half of the filter chamber is responsible for filtration, and the screen on the latter half of the filter chamber is responsible for dehydration. A sludge dewatering machine,
Sludge dewatering characterized in that the screen on the first half of the filtration chamber has openings in the form of slits on the upper side and the openings on the lower side have openings in the form of holes, and the screen on the second half of the filtration chamber has openings in the form of holes. Machine.   The screen in the first half of the filter chamber has a mesh that has a plurality of wedge wires on the upper side and has openings in the shape of slits between the wedge wires, and a lower side that has a mesh made of punching metal and has openings in the form of holes. The sludge dewatering machine according to claim 3, wherein the screen on the latter half side of the filter chamber has a mesh made of punching metal and open in a hole shape.   A screw provided with screw blades around the shaft center is arranged up and down, and the screen on the first half side of the filter chamber corresponds to the upper screw on the upper side and corresponds to the lower screw on the lower side. 4. The sludge dewatering machine according to 4.   The sludge dehydrator according to any one of claims 2, 4, and 5, wherein the screen in the first half of the filter chamber supports the outside of the plurality of wedge wires with a bar.

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