JP2023090239A - Pressure dehydration device having concentration mechanism and pressure dehydration method - Google Patents

Abstract

To provide a pressure dehydration device having a concentration mechanism made by integrating a concentration mechanism on the front stage in a filter plate row forming a filtration chamber and a dehydration mechanism that is provided continuously to the concentration mechanism, and a pressure dehydration method.SOLUTION: A pressure dehydration device having a concentration mechanism comprises: a concentration mechanism 9 in which a filter material 22 is provided in a concentration filtration chamber 21 formed in a hollow shape on the front stage in a filter plate row forming a filtration chamber of the pressure dehydration device, and which supplies the liquid concentrate from a communication path 28 opening to one part of the concentration filtration chamber 21, performs solid-liquid separation by making the liquid content pass through the filter material 22 while making the liquid concentrate pass in parallel to the filter material 22, and discharges the concentrated sludge to the concentration filtration chamber 21 on the next stage from the communication path 28 opening at a symmetric position of the communication path 28; a dehydration mechanism 10 which is integrally provided continuously to the discharge side of the concentration mechanism 9 and performs solid-liquid separation by making the liquid content pass through the filter material 22 provided in a dehydration filtration chamber 23 between dehydration filter plates 12 capable of opening/closing the concentrated sludge via the communication path 28b; and a return pipe 16 which returns a portion of the concentrated sludge supplied to the dehydration mechanism 10 from the concentration mechanism 9 to a liquid concentrate storage tank 13. Consequently, a cake with a low moisture content can be obtained.SELECTED DRAWING: Figure 1

Description

The present invention is a thickening system that integrates a thickening mechanism for thickening sludge generated from wastewater treatment facilities such as sewage, night soil, community wastewater, and factories, and a dewatering mechanism for dewatering the sludge thickened by the thickening mechanism. The present invention relates to a pressurized dewatering device having a mechanism and a pressurized dewatering method.

Conventionally, pressure dehydration equipment that presses thickened sludge using a gravity thickening tank or a mechanical thickener into a filtration chamber formed between a large number of parallel filter plates, and performs pressurization filtration by the pressurization pressure, and pressurization filtration by the pressurization pressure. A pressurized dehydrator is known in which dehydration is performed by pressurizing and dehydrating by supplying a pressurized fluid to a diaphragm chamber after performing dehydration. When performing dehydration using such a pressurized dehydrator, after closing the parallel filter plates and supplying concentrated sludge toward the undiluted solution supply channel formed in the row of filter plates, the adjacent filter plates It was dehydrated in the filtration room between. Thus, conventionally used pressurized dehydrator dewaters thickened sludge, and generally includes only a dehydration mechanism.

On the other hand, Patent Document 1 discloses a filtration and concentration device in which a plurality of filter plates are arranged, each of which includes a concentration section for concentrating the stock solution to a predetermined concentration and a filtration section for filtering the stock solution concentrated by the concentration section. A pressurized dehydrator integrated with a concentrating mechanism is known in which a concentrating section and a filtering section are formed in parallel filter plates.

In addition, Patent Document 2 discloses a continuous filtration and concentration device in which a plurality of filter frames each having a pair of flow path forming ribs at symmetrical positions on the inner peripheral wall and a plurality of filter plates are alternately arranged, and the undiluted solution is concentrated while being alternately flowed vertically. A concentrating mechanism in which the stock solution is pressurized and supplied in a staggered manner is known.

Japanese Patent Publication No. 06-096158 Japanese Utility Model Publication No. 48-005328

A conventional pressurized dehydrator has only a dewatering mechanism, and when dehydrating sludge, a gravity thickening tank installed separately from the pressurized dewatering device is used to thicken the sludge before dehydration. There are many. However, when performing gravity concentration, the concentration deteriorates due to the decrease in sedimentation due to the atomization of sludge particles and the increase in organic matter. There was a problem that the fluctuation of In addition, it was necessary to increase the volume of the tank in order to secure the residence time for allowing the particles to settle, and as the size of the apparatus increased, a large installation space had to be secured. In order to increase the concentration of sludge after gravity concentration, there is a method of mechanical concentration such as filter cloth concentration after gravity concentration. was

Patent Document 1 discloses a filtration and concentration device in which a plurality of filter plates having a concentration section and a filtration section are arranged, and a concentration mechanism and a dehydration mechanism are integrated. Since it is necessary to form a part and the filter plate structure is complicated, it takes time and effort to manufacture. After being concentrated in the concentrating portion of the filter plate, the undiluted solution is recovered in the undiluted solution recovery tank through the undiluted solution recovery line, and is supplied to the filtration portion through the concentrated undiluted solution supply line by the concentrated undiluted solution supply pump and filtered. Thus, since the thickening section and the dehydrating section are arranged in parallel, when the amount of thickened sludge produced in the thickening section is small, it cannot be continuously supplied to the dehydrating section. As a result, the continuity of sludge supply between the concentration section and the dewatering section could not be maintained, resulting in poor dewatering efficiency. In addition, it is necessary to separately install a tank, pipes, pumps, etc. for storing thickened sludge, and there is also a problem that the equipment cost and installation space increase.

The continuous filtration and concentration device disclosed in Patent Document 2 concentrates the stock solution with a concentration mechanism having the structure of a general pressurized dehydrator, but concentration and dehydration are performed by one pressurized dehydrator. It is not possible to do both. Therefore, in order to dewater the thickened sludge, it is necessary to provide a separate pressurized dehydrator, which causes the problem of increasing the size of the entire facility.

The present invention has been made in view of the above problems, and after concentrating the stock solution with a thickening mechanism provided integrally with the dehydrating mechanism, the thickened sludge is dehydrated with the dehydrating mechanism, thereby thickening the sludge by the thickening mechanism. A pressurized dehydrator and a pressurized dehydration method are provided that improve continuity with pressurized dewatering by a dehydration mechanism, realize high dehydration efficiency, and have a concentration mechanism that can make the entire facility compact.

A pressurized dehydrator in which a stock solution is supplied from one of a plurality of filtration chambers formed by a large number of filter plates arranged in parallel and solid-liquid separation is performed by the filter media provided in the filtration chambers. In the preceding stage, a filter medium is provided in a hollow concentrated filtration chamber, and the undiluted solution is supplied from a communication passage opened to one side of the concentrated filtration chamber, and the liquid content is passed through the filter medium while allowing the undiluted solution to flow parallel to the filter medium. A thickening mechanism that permeates and separates solid and liquid and discharges thickened sludge from a communicating passage that opens at a symmetrical position of the communicating passage to the next concentrated filtration chamber, and a communicating passage that is integrally connected to the discharge side of the thickening mechanism A dehydration mechanism that permeates liquid content through a filter medium provided in a dehydration filtration chamber between dehydration filter plates that can freely open and close thickened sludge through the By providing a return pipe for returning the part to the undiluted solution storage tank, it is possible to continuously perform sludge thickening and pressure dehydration with a compact device, and the concentrated liquid with fluidity flows in the thickening filtration chamber. As a result, SS (suspended solids) do not adhere to the surface of the filter medium, and clogging of the filter medium can also be prevented.

The concentration filter chamber is a hollow portion formed between a pair of adjacent concentration filter plates or a hollow portion formed within the concentration filter plate, so that the concentration filter plate to be used is an existing filter plate. Since it is only necessary to change the shape of the opening, it does not take time and effort to manufacture and install the filter plate.

By connecting a plurality of the concentration filtration chambers in parallel with the communication passages that are alternately formed continuously, the supplied undiluted solution can be efficiently concentrated in a short period of time and can be continuously supplied to the subsequent dehydration mechanism.

By providing a cleaning liquid supply pipe that communicates with the concentration filtration chamber, it is possible to supply the cleaning liquid to the plurality of concentration filtration chambers and the plurality of dehydration filtration chambers. clogging can be eliminated.

A pressurized dehydrator in which a stock solution is supplied from one of a plurality of filtration chambers formed by a large number of filter plates arranged in parallel and solid-liquid separation is performed by the filter media provided in the filtration chambers. In the previous stage, the undiluted solution is supplied from a communication passage that opens to one side of a hollow concentration filtration chamber provided with a filter medium, and while the undiluted solution is passed through the filter medium in parallel, the liquid is permeated through the filter medium to separate solids and liquids. Then, the thickened sludge is discharged to the thickening and filtering chamber of the next stage from the communicating passage that opens at the symmetrical position of the communicating passage, and is connected to the thickening and filtering chamber, and thickened in the dewatering and filtering chamber formed by the dewatering filter plate row that can be freely opened and closed. Sludge is supplied, liquid content permeates through the filter media provided in the dehydration filtration chamber, solid-liquid separation is performed, and dewatered cake is generated. By returning the sludge to the storage tank, the thickened sludge produced in the thickening mechanism can be continuously supplied to the dewatering mechanism, so that a dehydrated cake with a low moisture content can be produced in a short time.

In the pressurized dehydrator and the pressurized dewatering method having a thickening mechanism according to the present invention, the thickening mechanism is provided in the front stage of a plurality of filter plate rows, and the dehydrating mechanism is integrally connected with the thickening mechanism, so that sludge It is possible to increase the continuity of concentration and pressurized dehydration. Since the thickening mechanism and the dewatering mechanism are connected to each other through the communication passage, there is no need to provide a thickening tank for temporarily storing the thickened sludge between the thickening mechanism and the dehydrating mechanism. As a result, the thickened sludge can be immediately supplied to the dewatering mechanism without being stored in the thickening tank, so that the sludge can be continuously treated, and the improvement of the dehydration performance can be expected due to the reduction of miscellaneous time. Eliminating the thickening tank eliminates the need for peripheral piping and pumps, thereby reducing initial costs, running costs, and installation space required for equipment installation. Moreover, since the basic structure of the concentrating mechanism and the dehydrator is the same as that of the existing pressurized dehydrator, it can be operated by the operating method of the existing pressurized dehydrator. Since there is no need to separately install and operate a concentrator in the front stage of the pressurized dehydrator as in the conventional case, the operator's operation can be saved. In addition, the thickening mechanism and the dehydration mechanism are integrated, but each has an independent structure, so the dewatering performance is improved by selecting the appropriate filter media for each filter plate according to the properties of the sludge to be supplied. It is also possible to let

1 is a schematic configuration diagram of a pressurized dehydrator according to an embodiment of the present invention; FIG. Similarly, it is a schematic sectional side view of the concentrating mechanism of the pressurized dehydrator. Similarly, it is a schematic plan view of a concentrating filter plate that constitutes the concentrating mechanism. FIG. 4 is a schematic cross-sectional side view of a concentration mechanism according to another embodiment of the invention; 1 is a schematic cross-sectional side view of a dehydration mechanism of a pressurized dehydrator according to an embodiment of the present invention; FIG. FIG. 4 is a schematic cross-sectional side view of a concentration mechanism according to another embodiment of the invention; Similarly, it is a schematic plan view of a concentration filter plate.

FIG. 1 is a schematic configuration diagram of a pressurized dehydrator according to an embodiment of the present invention.
A pressurized dehydrator 1 has a pair of guide rails 4, 4 bridged between a front frame 2 and a rear frame 3, and has a large number of filter plates arranged in parallel. A movable head 5 is provided at the rear end of the row of filter plates and connected to a tightening cylinder 7 supported on the rear frame 3 so that each filter plate can be opened and closed along guide rails 4,4. The front frame 2 is provided with a stock solution supply pipe 8 for supplying the stock solution into the filtration chamber formed between the closed filter plates, and a discharge pipe 19 for discharging the filtrate after solid-liquid separation and the washing wastewater after washing. ing.

The undiluted solution supply pipe 8 has one end connected to the undiluted solution storage tank 13 and the other end connected to the front frame 2 via the undiluted solution supply pump 14 . A return pipe 16 is connected to the movable head 5, and part of the sludge discharged from the pressure dehydrator 1 is returned to the stock solution storage tank 13 as circulating sludge.

One end of the cleaning liquid supply pipe 15 is connected to the cleaning liquid storage tank 17 , and the other end is connected to the undiluted solution supply pipe 8 , the discharge pipe 19 and the return pipe 16 . The washing liquid can be supplied into the pressurized dehydrator 1 by operating the valves interposed in each pipe. The cleaning liquid in the cleaning liquid storage tank 17 is supplied by a cleaning liquid supply pump 18 interposed in the cleaning liquid supply pipe 15 . The washing liquid supplied to the pressurized dehydrator 1 is returned to the washing liquid storage tank 17 through the return pipe 16 after washing the filter medium 22 in each filtration chamber.
Alternatively, the other end of the cleaning liquid supply pipe 15 may be connected to the return pipe 16 to supply the cleaning liquid from the movable head 5 side.

The pressurized dehydrator 1 includes a thickening mechanism 9 positioned at the front stage of the row of filter plates to concentrate the raw liquid, a dehydrating mechanism 10 connected to the discharge side of the thickened sludge produced by the thickening mechanism 9 and dewatering the thickened sludge, are integrated. The forms of the concentration mechanism 9 and the dehydration mechanism 10 in this embodiment will be described in detail below.

2 and 3 are a schematic side sectional view of a concentrating mechanism of a pressurized dewatering apparatus according to an embodiment of the present invention, and a schematic plan view of a concentrating filter plate that constitutes the concentrating mechanism.
As shown in FIG. 2, the concentrating mechanism 9 is composed of a plurality of concentrating filter plates 11 arranged in parallel. Concentrating filtration chambers 21 are formed in hollow portions between a pair of adjacent concentrating filter plates 11, 11, and filter media 22 are stretched on the filtration floors 24 of the respective concentrating filtration chambers 21. As shown in FIG. The undiluted liquid supplied to the concentration filtration chamber 21 is solid-liquid separated by the filter medium 22 .

The undiluted solution is supplied to the concentration filtration chamber 21a located at the beginning end of the concentration mechanism 9 through a communication passage 28a penetrating the beginning thickening filter plate 11a connected to the front frame 2. As shown in FIG. A communication passage 28 for supplying from the front stage and a communication passage 28 for discharging to the rear stage are provided in the concentration filtration chamber 21a and each concentration filtration chamber 21 at the rear stage. It flows from the communication passage 28 toward the other communication passage 28 in the concentration filtration chambers 21 . The respective communication passages 28 are provided at symmetrical positions of the respective concentration filtration chambers 21, and the undiluted liquid is concentrated while alternately supplied to and discharged from each concentration filtration chamber 21 to become a concentrated liquid.

The concentrated liquid alternately flows through the concentrated filtration chambers 21 to form a concentrated liquid flow path 26. After the concentrated filtrate is separated by the filter medium 22 to increase the concentration concentration, it becomes concentrated sludge. The thickened sludge produced in the thickening mechanism 9 passes through the thickening filter chamber 21b formed between the terminal thickening filter plate 11b located at the end of the thickening mechanism 9 and the intermediate filter plate 25, which will be described later, and the communication passage 28b of the intermediate filter plate 25. is discharged to the dewatering mechanism 10 located in the latter stage.

In this embodiment, a communication passage 28a is provided above the beginning thickening filter plate 11a. The stock solution supplied from the stock solution supply pipe 8 to the concentration filtration chamber 21a through the upper communication passage 28a flows downward in parallel along the filter medium 22 in the concentration filtration chamber 21a, and passes through the lower communication passage 28 to the next stage. It is discharged to the concentration filter chamber 21 . In the next stage, it moves upward in parallel along the filter medium 22 in the concentration filtration chamber 21 and is discharged from the upper communication passage 28 to the concentration filtration chamber 21 of the next stage. The thickened sludge produced in the thickening mechanism 9 is supplied (discharged) from the intermediate filter plate 25 to the dewatering mechanism 10 while repeating reverse flow in the adjacent thickening and filtering chambers 21 .

In this embodiment, the communication passage 28a penetrating the starting thickening filter plate 11a is provided above, but it is limited to a configuration in which it is provided below or on the left and right and flows toward the communication passage 28 provided at a symmetrical position. do not. Moreover, although the filter cloth is used as the filter medium 22 stretched on each thickening filter plate 11, a metal filter medium such as a wedge wire or a metal mesh may be used instead of the filter cloth.

Communicating passages 28 communicating with the concentration filtration chambers 21 are the openings of the long holes formed above the concentration filter plate 11 shown in FIG. is the opening of Of the communication paths 28, 28 formed in each concentration filtration chamber 21, the communication path 28, which serves as a discharge path, is formed at a symmetrical position with respect to the communication path 28, which serves as a supply path, when the concentration filter plates 11 are arranged in parallel. Therefore, it becomes a supply path to the concentration filtration chamber 21 in the next stage. Since each communication passage 28 may be provided at a symmetrical position of each concentration filter chamber 21, it may be provided at a laterally symmetrical position or an obliquely symmetrical position of each of the adjacent concentration filter plates 11, 11. FIG.
In addition, regarding each communication path 28, as shown in FIG. 3(c), a plurality of circular ones may be formed.

The concentrated filtrate separated by the filter media 22 of the concentrated filter chambers 21 . The concentrated filtrate discharged through the filtrate discharge path 30 is discharged outside through the discharge pipe 19 .

FIG. 4 is a schematic cross-sectional side view of a concentrating mechanism according to another embodiment of the invention.
The supplied undiluted solution is concentrated while being alternately supplied and discharged in each of the concentration filtration chambers 21 every two chambers. Concentrating filter plates 11 are arranged in parallel. The undiluted solution supplied from the communication passages 28a, 28a opened above the thickening filter plates 11a, 11 forming the two thickening filter chambers 21a, 21a adjacent to the starting end side is introduced into the two thickening filter chambers 21a, 21a. flows downward along the filter medium 22 in parallel, and then flows toward the two concentrating filtration chambers 21, 21 in the latter stage from a plurality of communicating passages 28 positioned symmetrically with respect to the communicating passages 28a, 28a. The communication passages 28a, 28a above the thickening filter plate 11 are in communication with each other. A plurality of communication passages 28 below the thickening filter plate 11 are also communicated. The concentrated liquid supplied to the two rear-stage concentration filtration chambers 21, 21 rises in parallel along the filter medium 22 and is further supplied to the rear-stage concentration filtration chambers 21b, 21b via the communication passages 28. . Each of the communication passages 28 communicates the openings of the respective thickening filter plates 11 that constitute the two concentrated filtration chambers 21, 21 in which the concentrated liquid faces downward and the two concentrated filtration chambers 21, 21 in which the concentrated liquid faces upward. are formed.

The concentrating filtration chambers 21 forming a group of two chambers each have communicating passages 28 above and below each group. In addition, since the communicating passages 28 are also formed between adjacent groups, the concentrated liquid can alternately flow within each group. In this way, by alternately forming the communication paths 28 continuously, the concentrated liquid can be concentrated while flowing alternately. The thickened sludge produced in the thickening mechanism 9 is supplied to the dewatering mechanism 10 through the communication passage 28b of the intermediate filter plate 25 from the thickening filter chambers 21b, 21b forming a group at the end.

Note that the concentration filtration chambers 21 may be grouped by three or more chambers instead of by two chambers. The shape, number, position, etc. of the openings of the communication passages 28 of each thickening filter plate 11 to be used are appropriately selected in the same manner as in FIG.

The intermediate filter plate 25 shown in FIGS. 2 and 4 is provided between the terminal thickening filter plate 11b and the starting dewatering filter plate 12a, which will be described later. A chamber 21 is formed, and a dehydration filter chamber 23 is formed between the starting end dewatering filter plate 12a.

The intermediate filter plate 25 is formed with communication passages 28b that are open in the plate thickness direction, and communicate the concentration filter chambers 21 and the dehydration filter chambers 23 with each other. The communication path 28b is a supply path for thickened sludge, and supplies the thickened sludge produced in the thickening and filtering chambers 21 to the dewatering and filtering chamber 23. As shown in FIG. Since the communication path 28b only needs to allow communication between the concentration filtration chamber 21 and the dehydration filtration chamber 23, one or more openings are provided. The communication path 28b is provided above when the supply method to the subsequent dehydrator 10 is the top feed method, is provided in the center when the center feed method is used, and is disposed below when the bottom feed method is used. Design accordingly.

In the present embodiment, the intermediate filter plate 25 is arranged between the thickening mechanism 9 and the dehydrating mechanism 10 to supply thickened sludge from the thickening mechanism 9 to the dehydrating mechanism 10 . The communication path 28 of the terminal thickening filter plate 11b and the thickened sludge supply path 20 of the starting dewatering filter plate 12a located at the starting end of the dewatering mechanism 10 may be connected. In either form, a thickening tank for temporarily storing thickened sludge is not required between the thickening mechanism 9 and the dewatering mechanism 10, and the thickened sludge can be continuously supplied from the thickening mechanism 9 to the dehydrating mechanism 10, so the dehydration efficiency does not decrease. .

FIG. 5 is a schematic cross-sectional side view of the dehydration mechanism of the pressurized dehydrator according to the embodiment of the present invention.
The dehydration mechanism 10 is composed of a plurality of dehydration filter plates 12 arranged in parallel. Among the plurality of dewatering filter plates 12, the starting dewatering filter plate 12a located on the starting end side is connected to the concentrating mechanism 9 via the intermediate filter plate 25, and the terminal dewatering filter plate 12b located on the terminal side is removable. It is connected with the head 5 . A thickened sludge supply channel 20 is opened above each dewatering filter plate 12 , and a thickened sludge channel 27 is formed above the dehydration mechanism 10 by communicating with the filter plate when the filter plate is closed. Dehydration filter chambers 23 are formed between adjacent dewatering filter plates 12, 12, and a pair of filter media 22 are stretched in each dewatering filter chamber 23. As shown in FIG.

The thickened sludge produced by the thickening mechanism 9 flows into the thickened sludge flow path 27 through the communication passage 28b of the intermediate filter plate 25 . The thickened sludge that has flowed in is supplied to each of the dehydration and filtration chambers 23 . The descending thickened sludge separates the dehydrated filtrate by the filter medium 22 to produce a dehydrated cake. The dehydrated filtrate to be separated passes through the filter medium 22 and flows from the dewatering filter chamber 23 to the filtrate discharge channel 30 via the filtrate passage 29 formed in the filter bed 24 . The dehydrated filtrate discharged from the filtrate discharge path 30 is discharged to the outside through the discharge pipe 19 .
Regarding the opening of the thickened sludge supply channel 20, which is the opening of each dewatering filter plate 12, one long hole may be formed in the same manner as in the thickening mechanism 9, but the shape, number, etc. are not particularly limited and are subject to design conditions. Choose accordingly.

Further, an expandable and contractible diaphragm (not shown) may be stretched on the surface of at least one dewatering filter plate 12 forming each dewatering filter chamber 23 to squeeze the dehydrated cake in the dewatering filter chamber 23 .

Regarding the type of filter medium 22 stretched on the dewatering filter plate 12, there are no particular restrictions on the type of filter medium 22, such as filter cloth and metal filter medium. , and a traveling type filter medium 22 is arranged in the dehydration mechanism 10, and the filter medium 22 suitable for each mechanism can be selected. In order to improve the dehydration performance, it is also possible to stretch the filter medium 22 having a higher permeability than the dehydration mechanism 10 in the concentration mechanism 9 .

In this embodiment, if the shape of the filter plate used in the concentrating mechanism 9 is the same as the shape of the filter plate of the dewatering mechanism 10, any filter plate is rotated 180 degrees around its axis to change the position of the communication passage 28. At the same time, it is possible to increase or decrease the chambers of the concentrating mechanism 9 and the dehydrating mechanism 10 simply by changing the arrangement of the filter plate rows. As a result, it is also possible to construct an optimum pressurized dehydrator 1 according to fluctuations in sludge properties.
The number, material, shape, etc. of the filter plates arranged in the concentrating mechanism 9 and the dehydrating mechanism 10 are appropriately set according to the properties of the undiluted solution to be supplied.

FIG. 6 is a schematic cross-sectional side view of a concentrating mechanism according to another embodiment of the invention.
The concentration mechanism 9 is configured by alternately arranging the concentration filter plates 31 and the concentration filter plates 33 which are hollow inside. The thickening filter plate 31 and the thickening filter plate 33 each have a communication passage 28 opening above the filter frame forming a hollow portion, and the communication passages 28 communicate with each other. The thickening filter plate 31 has the filter medium 22 stretched on its surface and has the filtrate discharge path 30 below the filter frame. The concentration filter plate 33 has a concentration filtration chamber 21 as a hollow portion into which the undiluted solution supplied from the communication passage 28 flows. The undiluted liquid supplied to the concentrated filtration chamber 21 is subjected to solid-liquid separation into concentrated sludge and concentrated filtrate by the filter medium 22 of the adjacent concentrated filter plate 31 .
If necessary, a filter medium support member may be provided on the surface of each thickening filter plate 31, and the filter medium 22 may be stretched over the filter medium support member.

The undiluted solution is supplied to the thickening filter chamber 21a through the leading end thickening filter plate 31a connected to the front frame 2 and the communicating passages 28a, 28a above the adjacent thickening filter plate 33a. The undiluted solution supplied to the concentration filtration chamber 21a is directed downward in parallel along the filter media 22 stretched over the surfaces of the concentration filter plates 31a and 31 adjacent to the front and rear stages, and then flows through the concentration filter plate 33a and the concentration filter of the rear stage. It is condensed while flowing through the communication passages 28 below the plates 31 and 33 toward the concentrating filtration chamber 21b in the latter stage. The concentrated liquid that has flowed into the concentration filter chamber 21b in the latter stage rises in parallel along the filter media 22 stretched on the surfaces of the adjacent concentration filter plates 31, 31b, and passes through the communication passages 28b, 28b formed above to the latter stage. is supplied to the dewatering mechanism 10 connected to the . Concentrated liquids flowing in parallel through the respective concentrated filtration chambers 21 are solid-liquid separated by the filter media 22 . After passing through the filter medium 22 , the concentrated filtrate passes through the hollow portion of the concentrated filter plate 31 and is discharged from the filtrate discharge channel 30 . The hollow portion of the thickening filter plate 33 is the thickening filtration chamber 21, whereas the hollow portion of the thickening filter plate 31 is a concentrated filtrate discharge portion.

By arranging the communication paths 28 alternately upward and downward in this way, it is possible to form the concentrated liquid flow paths 26 in which the concentrated liquid alternately flows. The thickened sludge generated while repeating reverse flow in the adjacent thickening filter chamber 21 is continuously supplied (discharged) to the subsequent dehydration mechanism 10 through the communicating passage 28b of the terminal thickening filter plate 31b located at the end. In this configuration, as in FIG. 2, the communicating path of the terminal thickening filter plate 31b and the communicating path of the starting dewatering filter plate 12a are configured to communicate with each other. The position of the communication path 28 is not limited to this, either, and it may be formed in a symmetrical position or an obliquely symmetrical position of the filter frame.

In the case of FIG. 6, as in FIG. 4, a plurality of groups formed by two or more concentrating filtration chambers 21 adjacent to each other are formed, and connected to a plurality of pipes provided outside to alternately supply the concentrated solution to each group. It is good also as a structure which makes it flow.

FIG. 7 is a schematic plan view of a concentration mechanism according to another embodiment of the invention;
In FIG. 7(a), the channel-forming ribs 32 are arranged in the hollow portion of the thickening filter plate 33 of FIG. FIG. 7(b) shows a thickening filter plate 31 similar to that in FIG. The flow channel forming ribs 32 provided on the thickening filter plate 33 are arranged, for example, by arranging a set of two flow channel forming ribs 32, 32 with their ends bent at 90 degrees at symmetrical positions on the inner peripheral wall of the thickening filter plate 33. , a zigzag condensate flow path 26 can be formed from one end of the communication path 28 toward the communication path 28 at the symmetrical position of the communication path 28 . In addition, by arranging a set of two flow path forming ribs 32, 32 (not shown) that are spirally bent on the inner peripheral wall of the thickening filter plate 33, a spiral A flowing concentrate channel 26 can also be formed. By forming the long concentrated liquid flow path 26, the concentration time of the concentrated liquid in the concentrated filtration chamber 21 can be sufficiently ensured, so that the concentration concentration of the concentrated liquid can be increased. Accordingly, the dehydration efficiency in the subsequent dehydration filtration chamber 23 is improved.

<S1 plate closing process>
A plurality of thickening filter plates 11 and dewatering filter plates 12 arranged in parallel are closed by a clamping cylinder 7 to form thickening filter chambers 21 between the adjacent thickening filter plates 11, 11, and the adjacent dewatering filter plates 12. , 12, dehydrating and filtering chambers 23 are formed. A filter medium 22 is stretched in each concentration filtration chamber 21 and each dehydration filtration chamber 23 to form a space capable of solid-liquid separation. At this time, the valve V2 interposed in the discharge pipe 19 is open, and the other valves are closed.

<S2 press-fitting step>
After opening the valve V1 interposed in the undiluted solution supply pipe 8 and the valve V3 interposed in the return pipe 16, the undiluted solution supply pump 14 is driven. By driving the undiluted liquid supply pump 14 , the undiluted liquid in the undiluted liquid storage tank 13 is pressurized and supplied to the pressurized dehydrator 1 through the undiluted liquid supply pipe 8 . The stock solution is injected at a constant pressure using a predetermined value.

The undiluted liquid supplied to the pressurized dehydrator 1 is condensed while flowing alternately up and down in the plurality of concentrating filtration chambers 11 to form a condensed liquid flow path 26 . The thickened sludge produced by the thickening mechanism 9 at the front stage of the filter plate row is supplied through the communication passage 28b toward the plurality of dehydration filtration chambers 23 connected at the rear stage. Since the concentrated liquid flowing through the concentrated filtration chambers 11 contains a large amount of liquid and has fluidity, it can flow through the plurality of concentrated filtration chambers 21 by continuously injecting the undiluted liquid at a constant pressure.

The thickened sludge supplied (discharged) from the communication passage 28b flows toward the thickened sludge channel 27 formed in the upper part of the dewatering filter plates 12, and then supplied to the dewatering filter chambers 23 between the dewatering filter plates 12, 12. However, part of the thickened sludge is discharged from the movable head 5 side as circulating sludge and returned to the raw liquid storage tank 13 through the return pipe 16 . By circulating the thickened sludge in this way, a constant flow can be generated in the thickening/filtering chambers 21 .

1. After the undiluted liquid pressurized from the concentrated undiluted liquid supply pipe 8 flows toward the communication passage 28a of the starting thickening filter plate 11a, it is formed between the starting thickening filter plate 11a and the thickening filter plate 11 adjacent to the starting thickening filter plate 11a. It is concentrated while moving downward in the concentrated filtration chamber 21a. The downward concentrated liquid flows into the next-stage concentration filtration chamber 21 through the communication passages 28 located symmetrically with the communication passages 28a of the leading end concentration filter plate 11a, and then flows upward in the next-stage concentration filtration chamber 21. , through a communication passage 28 to form the next concentration filtration chamber 21 . In this manner, the sludge is concentrated by the filter medium 22 in each thickening/filtrating chamber 21 while flowing alternately in the thickening/filtrating chambers 21 to produce thickened sludge.

The concentrated liquid flowing through each concentrated filtration chamber 21 is solid-liquid separated by flowing the undiluted liquid in parallel along the filter media 22 of the filter bed 24 of the concentrated filtration chamber 21, thereby preventing SS from adhering to the surface of the filter media 22. Since clogging can be prevented, initial water permeability can be maintained. As a result, it is possible to reduce the frequency of cleaning the filter media 22, thereby reducing the amount of cleaning liquid used and the cost of electricity generated during cleaning.

The concentrated liquid flowing in each of the concentrated filtration chambers 21 spreads sufficiently within the concentrated filtration chambers 21, the concentrated filtrate is separated by the filter medium 22, and the separated concentrated filtrate passes through the filtrate passage 29 of the concentrated filter plate 11. It is discharged from the filtrate discharge passage 30. After that, it is discharged outside through the discharge pipe 19 from the filtrate discharge path 30 .

2. The thickened sludge produced by the dewatering/thickening mechanism 11 is continuously press-fed into the dewatering/filtering chambers 23 through the communication passages 28b of the intermediate filter plate 25. As shown in FIG. The supplied thickened sludge flows into the thickened sludge channel 27 and then is supplied to each dehydration and filtration chamber 23 .

The injected thickened sludge spreads sufficiently in the dehydration filtration chamber 23, and the dehydration filtrate is separated by the filter media 22 stretched inside. Solids accumulate between the filter media 22 to form a dewatered cake. The separated dehydrated filtrate passes through the filter medium 22 and is discharged from the filtrate discharge channel 30 through the filtrate passage 29 . After that, it is discharged from the discharge pipe 19 to the outside.

In this embodiment, since the communication passage 28b for the thickened sludge discharged from the thickening mechanism 9 is connected in series with the dewatering mechanism 10, the thickened sludge generated in the thickening mechanism 9 is continuously connected to the dewatering mechanism 10. can supply. Further, the supplied thickened sludge flows into the thickened sludge channel 27 and then is forced into each dehydration filter chamber 23 by the static pressure of the thickened sludge flowing through the thickened sludge channel 27 . Thereby, a dehydrated cake can be produced in a short time. In addition, since the connection is made through the communication passage 28b, installation of a thickened sludge storage tank for storing thickened sludge is not required, and associated pipes, pumps, etc. are not required, so that the entire facility can be made compact.
It should be noted that the press-fitting process continues for a predetermined period of time.

<S3. Plate opening process>
After pressurizing the stock solution for a certain period of time, the stock solution supply pump 14 is stopped and the valve V1 is closed. After that, the clamping cylinder 7 is driven to open the dewatering filter plates 12 of the dewatering mechanism 10, and the dehydrated cake formed in the dewatering filter chambers 23 is discharged. By opening the dewatering filter plates 12, the dehydrated cake falls out of the machine. At this time, only the dehydration mechanism 10 is opened, and the concentration filter plates 11 of the concentration mechanism 9 are not opened and are kept closed.
In addition, when using a diaphragm filter plate, a compression process is performed before the plate-opening process S3. Further, after the pressing step, the cleaning liquid may be supplied from the cleaning liquid supply pipe 15 to wash the cake, and after the impurities in the cake are discharged, the next step may be performed.

<S4. Filter medium washing process>
After discharging the dewatered cake, the clamping cylinder 7 is driven to close the dewatering filter plates 12 again. Since the concentrating mechanism 9 is in the plate closed state, by closing only the dehydration filter plates 12 .

After the dewatering filter plates 12 are closed, the valve V2 interposed in the discharge pipe 19 and the valve V3 interposed in the return pipe 16 are closed, and the valves V4, V5 and V5 interposed in the washing liquid supply pipe 15 are closed. The valve V7 interposed in the return pipe 16 is opened, and the washing liquid supply pump 18 is driven. The cleaning liquid in the cleaning liquid storage tank 17 is supplied to the concentrated filtration chambers 21 and the dehydration filtration chambers 21 through the cleaning liquid supply pipe 15 from the undiluted liquid supply section and the filtrate discharge section. Since each filtration chamber is filled with the cleaning liquid over time, the filter media 22 in each filtration chamber can be kept immersed, preventing the filter media 22 from drying out. As a result, the mother liquid adhering to the filter media 22 evaporates during the shutdown period until the start of the next dehydration operation, and clogging of the filter media 22 by crystals such as calcium carbonate and calcium sulfate does not occur.

The valves V4 and V5 may be opened at the same time or may be opened and closed alternately. Alternatively, a cleaning liquid supply pipe 15 may be added to supply the cleaning liquid from the movable head 5 side, and the cleaning liquid may be supplied from both sides of the pressurized dehydrator 1 by operating the valve V6. Since it is sufficient to supply the cleaning liquid into each filtration chamber, the configuration of the cleaning liquid supply pipe 15 is appropriately selected according to the design items.

After the concentration filtration chambers 21 are immersed in the washing liquid, the dewatering filtration chambers 23 are immersed in the washing liquid to remove SS (suspended solids) adhering to the surface of the filter media in each filtration chamber, and the dehydration filtration chambers 23 are discharged as washing drainage. The thickened sludge is discharged from the return pipe 16 through the thickened sludge supply passages 20 . The washing waste water is returned to the washing liquid storage tank 17 through the return pipe 16 . In this embodiment, the cleaning of the filter medium is performed by circulation cleaning, and the supplied cleaning liquid is circulated in the filtration chamber. Therefore, the SS is washed away by the cleaning liquid supplied later, and the SS can be efficiently removed. Circulation washing is performed for a predetermined period of time using a timer, but may be terminated when a desired value is detected by measuring the filtrate concentration or the like.
The cleaning wastewater returned to the cleaning liquid storage tank 17 is appropriately subjected to solid-liquid separation by a known means to remove SS. If the cleaning waste water is highly turbid and cannot be reused, the cleaning water is separately supplied to the cleaning liquid storage tank 17 while discharging the cleaning waste water to the outside.

After the filter medium cleaning step S4, the cleaning liquid supply pump 18 is stopped, the valves V4 and V5 are closed, and the valve V2 is opened to discharge the cleaning wastewater remaining in each filtration chamber. Cleaning is not performed every time after the dehydration operation is completed, but the cleaning cycle is set before the dehydration operation is started, and the cleaning is performed when the number of times of operation reaches the set value. A method of measuring the concentration of the discharged filtrate and performing washing when the measured value reaches the reference value may be employed.

In this embodiment, the concentrating mechanism 9 and the dehydrating mechanism 10 are immersed and washed, but only the concentrating mechanism 9 is immersed and washed, and the dehydrating mechanism 10 cleans the filter medium 22 by injecting a cleaning liquid using a known cleaning method. good too.

As for the index used for switching between steps, it is appropriately selected according to the conditions, such as switching when a desired value is obtained while measuring the pressure, filtrate concentration, etc., instead of a predetermined time.

The present invention is not limited to the embodiments described above and illustrated in the drawings, and modifications can be made without departing from the gist of the invention described in the claims.

Since the pressurized dehydrator and the pressurized dewatering method having the thickening mechanism according to the present invention are integrally configured by connecting the thickening mechanism and the dehydrating mechanism, sludge can be thickened and dewatered with one device. Since there is no need to install a thickener separately from the dehydrator, installation costs and operating costs for the thickener are not required, and the entire facility can be made compact. In addition, the thickened sludge is supplied from the thickening mechanism to the dewatering mechanism without going through the thickening tank, and the thickened sludge can be continuously supplied to the dehydrator without remaining in the thickening tank for a long time. of dehydrated cake can be produced. Since it is possible to dehydrate highly efficiently with a compact device, it is suitable as a filter press for production processes and industrial wastewater containing a large amount of inorganic substances. It can also be used for time filtration.

1 Pressurized Dehydrator 9 Concentration Mechanism 10 Dehydration Mechanism 12 Dehydration Filter Plate 13 Undiluted Solution Storage Tank 15 Washing Liquid Supply Pipe 16 Return Pipe 21 Concentration Filtration Chamber 22 Filter Media 23 Dehydration Filtration Chambers 28, 28b Communicating Path

Claims (6)

A pressurized dehydrator that supplies a stock solution from one of a plurality of filtration chambers formed by parallelly forming a large number of filter plates, and performs solid-liquid separation with a filter medium provided in the filtration chamber,
In front of the row of filter plates that form the filtration chamber,
A filter medium (22) is provided in the concentration filtration chamber (21) formed in a hollow shape. While the undiluted liquid is passed through the filter medium (22), the liquid is permeated and solid-liquid separated. A thickening mechanism (9) for discharging thickened sludge;
A filter medium (22) provided in a dewatering filter chamber (23) between dewatering filter plates (12) integrally connected to the discharge side of the thickening mechanism (9) and capable of freely opening and closing thickened sludge through a communication passage (28b). ), a dehydration mechanism (10) that permeates the liquid and separates the solid from the liquid;
and a return pipe (16) for returning part of the thickened sludge supplied from the thickening mechanism (9) to the dewatering mechanism (10) to the raw liquid storage tank (13). dehydration equipment. 2. The pressurized dehydrator having a concentrating mechanism according to claim 1, wherein said concentrating filter chamber (21) is a hollow portion formed between a pair of said concentrating filter plates (11) adjacent to each other. 2. The pressurized dehydrator having a concentrating mechanism according to claim 1, wherein said concentrating filter chamber (21) is a hollow portion formed in said concentrating filter plate (11). The concentration filtration chamber (21) according to any one of claims 1 to 3, characterized in that a plurality of the concentration filtration chambers (21) communicate with the communication passages (28) that are arranged in parallel and alternately continuously formed. A pressurized dewatering device with a mechanism. 5. The pressurized dehydrator having a concentrating mechanism according to any one of claims 1 to 4, further comprising a washing liquid supply pipe (15) communicating with the concentrating filtration chamber (21). A pressurized dehydrator that supplies a stock solution from one of a plurality of filtration chambers formed by parallelly forming a large number of filter plates, and performs solid-liquid separation with a filter medium provided in the filtration chamber,
At the front stage of the filter plate row forming the filtration chamber,
The stock solution is supplied from a communication passage (22) that opens to one side of a hollow concentration filtration chamber (21) provided with a filter medium (22), and the stock solution is passed through the filter medium (22) in parallel with the filter medium (22). ) permeates the liquid to separate solid and liquid, and discharges the thickened sludge from the communication passage (22) that opens at a symmetrical position of the communication passage (22) to the next thickening filtration chamber (21),
The thickened sludge is supplied to the dewatering and filtering chamber (23) connected to the thickening and filtering chamber (21) and formed by a row of dewatering filter plates (12) that can be freely opened and closed. Permeate the liquid to separate the solid and liquid to produce a dehydrated cake,
A pressurized dehydration method having a thickening mechanism, characterized in that part of thickened sludge supplied from a thickening filter chamber (21) to a dehydrating filter chamber (23) is returned to a stock solution storage tank (13).

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