JP2020142210A - Sewage treatment method and sewage treatment device - Google Patents

Abstract

To provide a sewage treatment method and a sewage treatment device where contaminants contained in sewage are crushed and cut to suitable sizes.SOLUTION: A sewage treatment method includes: a crushing step making first contaminants by flowing sewage in a twin-shaft crusher and crushing contaminants and obtaining a first treatment liquid 38; and a cutting step making second contaminants by flowing the first treatment liquid 38 in a cutter 30 and cutting and obtaining a second treatment liquid 39. In the sewage treatment device, the twin-shaft crusher makes the first contaminants by crushing the contaminants while pinching and has the cutter 30 having a cutting blade 35 held with a holder rotating around a rotation axis in a flow direction of the first treatment liquid 38 and an opposite plate 34 having a plurality of permeation holes disposed so as to cross the flow direction of the first treatment liquid 38. In the cutting step, the second contaminants are made by cutting the first contaminants by rotating the cutting blade 35 in an opposite state being adjacent to or in contact with the opposite plate 34 and the second treatment liquid 39 is made by permeating the second contaminants passing the permeation holes.SELECTED DRAWING: Figure 8

Description

The present invention relates to a sewage treatment method and a sewage treatment apparatus.

Conventionally, sewage such as domestic effluent, business establishment effluent, and factory effluent is drained to a sewage pipe, and is collected and treated at a sewage treatment plant via a relay pumping station and a sewer trunk line. The treated water is discharged into rivers and the sea.

The drained sewage includes, for example, plastics, underwear, rags, fibers such as absorbent cotton, and various impurities such as waste cloth, toilet paper, and hair. These contaminants cannot be discharged into rivers or the sea together with the water treated at the sewage treatment plant, for example, they are collected by screen equipment installed in the sand basins of relay pumping stations and sewage treatment plants, and are industrialized. Treated as waste.

In recent years, taking advantage of the effective use of energy and the economies of scale of sewage treatment plants, there is a tendency to consolidate sewage other than conventional sewage at sewage treatment plants and promote treatment. Here, examples of sewage other than conventional sewage include sewage from septic tanks, agricultural / fishery settlement drainage facilities, etc., and these sewage may include food waste, industrial waste, and diaper pieces.

By promoting intensive treatment at this sewage treatment plant, the amount of contaminants flowing into the sewage treatment plant tends to increase.

In a sewage treatment plant, an increase in contaminants causes various problems in the tank (pond) and equipment provided in each process of sewage treatment.

Therefore, in order to increase the amount of contaminants, it is possible to adopt a method of suppressing defects by crushing the contaminants to a suitable size.

Patent Document 1 and Patent Document 2 are disclosed as techniques for crushing contaminants. Patent Document 1 relates to an apparatus provided with a first crushing means, a receiving water tank, and a second crushing means, and is a technique for crushing solid foreign substances such as residue by these crushing means. However, since these crushing means crush the solid foreign matter with a pair of upright crushing units, the crushed material is not cut and extends in a band shape. Then, the crushed material adheres to or gets entangled in the tank (pond) or equipment, causing a problem.

Japanese Patent No. 5336266 Special Table 2012-521285 Special Table 2013-537103

A main problem to be solved by the present invention is to provide a sewage treatment method and a sewage treatment apparatus for crushing and cutting impurities contained in sewage to a suitable size.

Typical aspects of the present invention that have solved the above problems are as follows.

<First aspect>
A crushing step of flowing sewage into a twin-screw crusher and crushing the contaminants contained in the sewage to obtain a first contaminant, and obtaining a first treatment liquid containing the first contaminant.
It has a cutting step of flowing the first treatment liquid into a cutting device, cutting the first contaminant to obtain a second contaminant, and forming a second treatment liquid containing the second contaminant.
The biaxial crusher is
It is a device provided with two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushed while sandwiching the contaminants with these rotating shafts to obtain the first contaminants.
The cutting device intersects the flow direction of the first treatment liquid with the cutting blade held by the holder rotating around the rotation axis in the flow direction of the first treatment liquid in the flow of the first treatment liquid. It is provided with a facing plate having a plurality of through holes, which is provided in the above manner.
In the cutting step, the cutting blade is rotated in a state of facing or in close contact with the facing plate to cut the first contaminant into the second contaminant, and the through hole of the facing plate is permeated. The second treatment liquid is used.
A sewage treatment method characterized by that.

Contaminants contained in sewage can be collected by, for example, a screen equipment installed in a relay pumping station or a sand basin, but impurities that have passed through the screen equipment can be collected in a treatment facility or treatment equipment downstream of the screen equipment. It adheres to or gets entangled in the treatment facility and has a significant effect on the operation of the treatment facility. When the sewage containing the contaminants was allowed to flow into the twin-screw crusher, the contaminants sandwiched between the rotating shafts were crushed, and as a result, the crushed first contaminant and the crushed first contaminant passed through the twin-screw crusher without being crushed. A first treatment liquid containing small-sized impurities is obtained. The thickness of the first contaminant is about the same as the width of the rotating shafts. However, among the first contaminants, there are some that are not thick but are long filaments or strips. Therefore, the first treatment liquid containing the first contaminants is sent to the cutting device, and the cutting blade provided in the cutting device is rotated in a state of being close to or in contact with the facing plate to cut the first contaminants. Then, the contaminants contained in the second treatment liquid are composed of those having a suitable size that have passed through the twin-screw crushing device and the cutting device. Therefore, the treatment facilities and treatment equipment provided downstream, and these It is possible to prevent the burr portion from adhering to or getting entangled.

Of the impurities sent to the cutting device, the impurities having a size that cannot pass through the through hole of the facing plate stay (catch) on the facing plate. The contaminants that have stayed (caught) on the facing plate are cut by the rotation of the cutting blade. The contaminants remaining on the facing plate are cut and permeate through the permeation holes along the sewage stream.

If the contaminants remain attached to the facing plate, depending on the sewage to be treated, the contaminants may gradually accumulate on the facing plate due to the continuous or intermittent inflow of the first treatment liquid, and solidify or enlarge. It may cause blockage of the facing plate. When the cutting blade is rotated in a state of facing or in contact with the facing plate, impurities adhering to the facing plate are scraped off by the cutting blade. As a result, it is possible to prevent impurities from accumulating on the facing plate.

<Second aspect>
The biaxial crushing device crushes the contaminants into first contaminants having a thickness of 10 mm or less.
Examples of the cutting device include cutting the first contaminant into a second contaminant having a length of 50 mm or less.

Since these devices can obtain impurities having a thickness of 10 mm or less and a length of 50 mm or less, the obtained impurities adhere to and become entangled with the processing facilities and equipment provided downstream and the burrs thereof. It has the effect that it can be further suppressed.

<Third aspect>
The cutting device has an inflow portion through which the first treatment liquid flows.
An embodiment in which the facing plate is provided so that the angle formed by the facing plate and the inflow direction of the first processing liquid in the inflow portion of the cutting device is an acute angle can be mentioned.

Since the facing plate has an acute angle with respect to the flow direction of the first treatment liquid in the inflow portion of the cutting device, the through hole also has an acute angle. When the facing plate is provided in this way, it becomes difficult for impurities to pass through the through hole, and it becomes easy for the contaminants to be caught and stayed on the facing plate. Not only relatively long impurities but also relatively small impurities can easily stay on the facing plate, so that the impurities can be cut more finely.

<Fourth aspect>
An embodiment in which the time for the first treatment liquid flowing out of the twin-screw crushing device to reach the cutting device is within 60 seconds can be mentioned.

The first treatment liquid contains the first contaminants crushed by a crusher. If the first contaminant is left uncut for a while, the first contaminant may be deformed or re-aggregated into a large mass, making it difficult to cut with the cutting device. Therefore, by setting the time for the first treatment liquid to reach the cutting device within 60 seconds, there is an effect of preventing deformation and reaggregation of contaminants and making it easy to cut with the cutting device. ..

<Fifth aspect>
A sewage treatment device that crushes and cuts impurities contained in the inflowing sewage.
The sewage treatment device
A twin-screw crusher that crushes impurities into the first contaminants and obtains a first treatment liquid containing the first contaminants.
It comprises a cutting device for cutting the first contaminant to obtain a second contaminant and obtaining a second treatment liquid containing the second contaminant.
The biaxial crushing device includes two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushes the contaminants while sandwiching them between the rotating shafts to obtain the first contaminants. Yes,
The cutting device intersects the flow direction of the first treatment liquid with a cutting blade held by a holder that rotates around the rotation axis in the flow direction of the first treatment liquid in the flow of the first treatment liquid. The cutting blade is rotated in a facing state in close proximity to or in contact with the facing plate to cut the first contaminant and the second contamination. It is a thing,
It can be mentioned that the sewage treatment apparatus is characterized by this.

According to the present invention, by crushing and finely cutting impurities contained in sewage, it is possible to suppress problems such as adhesion to sewage treatment facilities and treatment equipment, entanglement, and blockage.

It is a figure which shows the biaxial crushing apparatus. It is a figure which shows the twin-screw crusher of another embodiment. It is explanatory drawing which sewage passes through a group of crushing disks. It is explanatory drawing of the cutting device. It is a figure which shows the main part of crushing of a cutting apparatus. It is a figure which shows an example of the facing plate. It is a figure which shows another form of the cutting apparatus. It is a figure which shows the processing flow. It is explanatory drawing of the angle formed by the facing plate and the inflow direction of the 1st processing liquid in the inflow part.

A mode for carrying out the present invention will be described. The embodiment of the present invention is an example of the present invention.

(Sewage treatment facility)
Since sewage drained from homes and business establishments is sewage, it flows into sewage pipes and sewer trunk lines, and also flows into sewage treatment plants via relay pumping stations. The sewage that has flowed into the sewage treatment plant is discharged to the outside of the system through, for example, a sand basin, a first settling basin, a reaction tank, a final settling basin, and a chlorine-mixed area. The sludge (raw sludge) that settled on the bottom of the pond in the first settling basin and the activated sludge that settled on the bottom of the pond in the final settling basin are temporarily stored in the sludge storage tank and mixed. Then, the volume of this mixed sludge is reduced by concentration, dehydration, incineration, etc. at the sludge treatment facility. Each treatment facility such as the first settling basin, reaction tank, final settling basin, and chlorine-mixed area is equipped with various mechanical equipment such as measuring equipment, agitator, and sludge scraper. The sludge sent to the sludge treatment facility is treated, for example, through a concentration tank, a digestion tank, a dehydrator, and an incinerator.

(sewage)
Conventionally, sewage was mainly composed of domestic wastewater, industrial wastewater, and business site wastewater. In addition, plants such as branches and leaves, stems and grass, soil, etc. may also be mixed in the sewage. In recent years, taking advantage of the economies of scale of sewage treatment plants, there is a tendency to incinerate sludge generated by consolidating septic tank wastewater, agricultural wastewater, food waste, diapers, etc. into the sewerage system to convert it into energy. However, if these are allowed to flow into a sewage treatment plant together with sewage and are intensively treated, the amount of contaminants will also increase.

(Contaminants)
Contaminants contained in sewage of sewage treatment facilities (for example, pumping stations, storage pipes, sewage treatment plants, sludge treatment facilities, etc.) include plastics, underwear, rags, fibers such as defatted cotton, waste cloth, toilet paper, and hair. , Garbage, oil balls, and diaper pieces can be exemplified, but are not limited thereto.

Contaminants can be collected by the screen equipment provided in the pumping station or sand basin, but in general, the forms of impurities (for example, size and length) vary, so they are collected by the same screen equipment. Some are transparent without being used. If sewage containing contaminants flows into the sewage treatment plant, especially each treatment facility after the first settling basin, troubles such as malfunction of the equipment due to contamination of the equipment installed in each treatment facility. In some cases, it will hinder the operation of the entire sewage treatment plant. In addition, a heat exchanger may be provided to heat the sludge when the sludge is reduced in volume in the digestion tank, but impurities get entangled in the piping inside the heat exchanger and block the heat exchanger. It may cause a problem.

In order to reduce such troubles and malfunctions as much as possible, it is advisable to take measures to eliminate adhesion and entanglement due to contaminants on equipment and piping. For example, measures can be taken to reduce the size by crushing or cutting impurities. In order to crush or cut the contaminants, known means can be taken without particular limitation, but it is preferable to equip the sewage treatment facility with a crushing device or a cutting device.

(Crushing device)
The structure of the crusher is not limited, but a crusher having a plurality of rotating shafts (for example, a biaxial shear crusher or a multiaxial shear crusher) can be used. The biaxial crushing device 20 will be described below as an example. As a biaxial crushing device, an example may be exemplified which is provided with two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushed while sandwiching the contaminants between these rotating shafts to obtain the first contaminant. .. The biaxial crusher 20 has two substantially parallel first rotating shafts 24A and second rotating shafts 24B that rotate around a shaft core. The first rotating shaft 24A and the second rotating shaft 24B may be rotated by a gear motor or the like. It is preferable to use a form in which the first rotating shaft 24A is provided with a plurality of crushing disks 23A provided with a plurality of crushing blades 23a protruding outward in the radial direction in the axial direction. It is preferable that at least one crushing blade 23a is provided on the outer peripheral portion of the crushing disk 23A. The positions of the crushing blades 23a of the crushing disk 23A group along the axis direction may be different for each crushing disk 23A in the direction around the axis, or may be arranged in a row. Similarly, the second rotating shaft 24B is also provided with a plurality of crushing disks 23B provided with a plurality of crushing blades 23b protruding outward in the radial direction in the axial direction. There is at least one crushing blade 23b on the outer peripheral portion, and the position of the crushing blade 23b of the crushing disk 23B along the axis direction may be different for each crushing disk 23B in the axial direction, or in a row. You may line up in. The crushing disk 23A group and the crushing disk 23B group may be arranged at intervals along the axis, or adjacent crushing disks may be arranged so as to be in close contact with each other. The plane direction of each of the crushing disk 23A and the crushing disk 23B is substantially perpendicular to the rotation axis direction. The structure may be such that the first rotating shaft 24A having the crushing blade 23a and the second rotating shaft 24B having the crushing blade 23b are arranged in the casing 25. In this structure, the sewage 10 may flow so that the sewage 10 flows into the crushing device 20 from the inflow portion 22 provided in the casing 25 and the first treatment liquid 38 flows out from the outflow portion 21. It is preferable that the crushing disk 23A group provided on the first rotating shaft 24A and the crushing disk 23B group provided on the second rotating shaft 24B are separated from each other by 7 to 10 mm. Further, both rotation shafts 24A and 24B may be arranged in a direction intersecting the inflow direction of the sewage 10.

The casing 25 does not necessarily have to be provided, and a biaxial crushing device 20 that does not have the casing 25 may be provided in a water channel or a pipe through which sewage flows. Further, all of the sewage 10 may be sent to the twin-screw crusher 20, or a part of the sewage 10 may be sent, but it is preferable to send all of the sewage 10.

When the sewage 10 is made to flow into the crushing device, the impurities contained in the sewage 10 are crushed by the crushing blade. Then, the treatment liquid 38 containing the crushed contaminants (hereinafter, also referred to as “first treatment liquid 38”) is discharged from the crusher. The relatively small contaminants are either appropriately crushed by the crusher or passed through without being crushed. In addition, relatively large contaminants may be crushed or compressed to the thickness of the distance between the rotating shafts to form a thread-like or strip-like form. The thread-like or strip-shaped morphology contained in the first treatment liquid 38 has, for example, a thickness of about 10 mm or less, but there are also those having a length of, for example, more than 50 cm, and these filament-like or strip-shaped morphologies are There is a risk of causing problems such as sticking to or entanglement with equipment installed downstream of the processing process. The contaminants contained in the first treatment liquid 38 that have passed through the crushing apparatus include crushed first contaminants and contaminants that have passed between the rotating shafts without being crushed.

(Cutting device)
As the cutting device, the configuration of the cutting device is not particularly limited as long as it is crushed by a cutting blade, but the cutting device 30 shown in the present embodiment can be preferably used for cutting contaminants. .. Further, the cutting device disclosed in Patent Document 2 and Patent Document 3 and the product "Rotacut" sold by Tsukishima Technomente Service Co., Ltd. may be used. The cutting device 30 shown in the present embodiment intersects the cutting blade 35 held by the holder 32 that rotates around the rotation axis of the flow direction 38b of the first treatment liquid 38 and the flow direction 38b of the first treatment liquid 38. It is provided with a facing plate 34 having a plurality of through holes 34a provided. The cutting blade 35 may have a cutting blade main body as a blade, or may have a rotary blade 35b provided with a cutting edge 35a. The contaminants are sandwiched between the cutting blade 35 and the facing plate 34, and are cut by receiving a shearing force. Explaining with reference to FIG. 4, the cutting device 30 is provided with a cutting blade 35 (rotary blade 35b and a cutting edge 35a provided on the rotary blade) facing the facing plate 34 surface. A plurality of transmission holes 34a penetrating the facing plate 34 are provided on the surface of the facing plate 34. The facing plate 34 may or may not include a blade. When the blade is provided, for example, the blade may be provided on the upstream side surface 34A of the first treatment liquid 38 in the facing plate 34, or the edge of the transmission hole may be formed in a blade shape. The form of the facing plate 34 may be a net-like one, or a so-called net blade in which the net itself is a cutting edge. Further, a perforated plate, a cribriform plate, or a lattice plate may be used, and a form in which the edge of the through hole in the perforated plate, the cribriform plate, or the lattice plate is formed by the cutting edge can be presented. Further, as shown in FIG. 6, it may be in the form of a facing plate in which transmission holes 34a having a substantially quadrangular shape or a substantially triangular shape are arranged while gradually expanding from the center to the outside in a spiral shape.

The cutting blade 35 may be installed on the upstream side of the facing plate 34. The contaminants are cut by the shearing force generated between the facing plate 34 and the cutting blade 35 when passing through the through hole 34a of the facing plate 34, but when arranged in this way, the first one flowing through the cutting device 30. Of the impurities contained in the treatment liquid, the impurities remaining (or caught) on the facing plate 34 are preferably cut by the rotating cutting blade 35.

The cutting blade 35 is provided in a rotatable holder 32, and when the holder 32 rotates, the cutting blade 35 rotates along the upstream plane 34A. The cutting blade 35a and the upstream plane 34A of the facing plate 34 rotate in close or in contact with each other.

When the cutting blade 35 is in contact with the upstream flat surface 34A of the facing plate 34, the rotation of the cutting blade 35 causes the cutting blade 35 to scrape off the contaminants adhering to the upstream flat surface 34A, and the contaminants are surely removed. It is suitable for being cut into. As an example of a means for maintaining the state in which the cutting edge 35a of the cutting blade 35 is in contact with the upstream flat surface 34A, the holder 32 provided in the cutting blade 35 is moved from the cutting blade 35 toward the facing plate 34 (biasing direction) 42. The means 33a for urging the vehicle can be mentioned. As a result, the cutting blade 35 can rotate while being pulled (biased) in the urging direction 42 and in contact with the upstream plane 34A of the facing plate 34. As the urging means 33a, known means such as a spring and a hydraulic cylinder can be used. The holder 32 may be rotated by a gear motor or the like.

The cutting blade 35 can be formed in the shape of a rotary blade. In this case, the number of blades can be set as appropriate. For example, it may be one sheet, or it may be any number of 2 to 8 sheets such as 2, 3, 4, 5, 5, and 8.

The shape of the transmission hole 34a of the facing plate 34 is not particularly limited, and may be, for example, a polygonal shape consisting of a substantially circular shape, a substantially triangular shape to a substantially hexagonal shape, a grid shape, a net shape, or the like. The width (or diameter) of the transmission hole 34a can be appropriately set, and is preferably 10 to 40 mm because impurities are appropriately cut and penetrate the transmission hole 34a.

The cutting device 30 of the present embodiment includes an inflow portion 36 into which the first treated water 38 flows in and an outflow portion 37 in which the water that has passed through the facing plate 34, that is, the second treated water 39 flows out. The facing plate 34 is provided so as to intersect the inflow direction 38a of the first treated water 38 in the inflow portion 36. The angle θ formed by the facing plate 34 (that is, the inclination 34r of the facing plate 34 surface) and the inflow direction 38a of the first treatment liquid 38 in the inflow portion 36 of the cutting device 30 may be a right angle, but as shown in FIG. It is preferable to make the angle sharp. In particular, it is preferable that the angle θ when the angle is acute is 15 ° or more. When the angle is sharp, the contaminants are easily caught by the facing plate 34 and stay there, so that the amount of contaminants to be cut increases, and as a result, the second treatment liquid containing a large amount of the contaminants cut short is discharged from the cutting device 30. .. When the angle θ is smaller than 15 °, the inflow direction 38a of the first treatment liquid and the plane of the facing plate 34 become close to parallel, and the speed at which the first treatment liquid permeates the surface of the facing plate 34 decreases hydraulically. The flow rate of the first treatment liquid that permeates the facing plate 34 is reduced, and as a result, the amount of sewage treated per unit time is reduced.

The facing plate 34 and the cutting blade 35 can be provided in the casing. The casing can be composed of two chambers, and a facing plate 34 may be provided so as to partition the first chamber 40 and the second chamber 41. The first chamber is provided with the above-mentioned cutting blade 35 and the inflow portion 36, and the second chamber is provided with the outflow portion 37. In this case, the holder 32 provided in the cutting blade 35 may be extended toward the second chamber and arranged so as to extend to the urging means 33a provided in the upper part of the second chamber. The first treatment liquid 38 that has flowed into the first chamber passes through the facing plate 34 and is guided to the second chamber, and is discharged from the outflow portion 37 as the second treatment liquid 39.

Further, a cutting device having a facing plate 34 and a cutting blade 35 may be provided in a water channel or a pipe through which the first treatment liquid 38 flows without providing a casing. In this case, needless to say, the cutting blade 35 is arranged on the upstream side and the facing plate 34 is arranged on the downstream side of the flow direction of the first treatment liquid 38.

The first treatment liquid 38 may be completely permeated through the facing plate 34 or a part thereof, but it is preferable that all of the first treatment liquid 38 is permeated.

The impurities contained in the first treatment liquid 38, particularly the filamentous material and the strip-shaped material, are cut by receiving a cutting force (shearing force) by the rotatable cutting blade 35 and / or the facing plate 34. Therefore, most of the impurities contained in the second treatment liquid 39 have a thickness of 10 mm or less and a length of 50 mm or less, so that they may adhere to or get entangled with various facilities provided on the downstream side of the cutting device. It can be suppressed.

As another embodiment, the sewage 10 can be directly sent to the cutting device 30 without being sent to the crushing device 20. However, in this "other embodiment", relatively large contaminants contained in the sewage stay on the facing plate 34 one after another, resulting in blockage of the cutting device 30. Therefore, when only the cutting device 30 is provided without providing the crushing device 20, it is preferable to install it in a sewage treatment facility where there are relatively few large impurities. For example, it is preferable to first install the cutting device 30 in the drawn sludge pipe of the settling basin, the inflow pipe and the outflow pipe of each of the concentration tank and the digestion tank.

Explaining another embodiment of the cutting device with reference to FIG. 7, the cutting device 130 is provided with a cutting blade 135 (a blade 135a attached to the rotary blade 135b) on the side facing the facing plate 134. .. The facing plate 134 is provided with a plurality of through holes penetrating the facing plate 134. The cutting blade 135 is provided with a holder 132 that is rotated by a gear motor 152 or the like, and the cutting blade 135 is rotated along the surface of the facing plate 134 by the rotation of the holder 132. The cutting blade 135 and the upstream side surface of the first treatment liquid 38 on the facing plate 134 are in contact with each other. A means 133 is provided for urging the cutting blade 135 in the direction (biasing direction) from the cutting blade 135 toward the facing plate 134 in order to bring the cutting blade 135 into contact with the facing plate 134. Further, the contaminants that cannot be completely cut and cannot pass through the facing plate 134 can be taken out from the take-out unit 151 provided in the lower part of the cutting device 130. Further, when the operation of the main body is stopped, the upper portion of the cutting device 130 (above the facing plate 134) can be moved counterclockwise with respect to the paper surface to open the fulcrum shaft 100 provided in the main body 130. Then, the inside of the casing 136 can be visually recognized from above, and the maintenance inside the main body can be easily performed. When the cutting device 130 is operated with the upper portion of the cutting device 130 closed, the first treatment liquid 38 sent to the cutting device 130 permeates through the facing plate 134, and as a result, the second treatment liquid 39 becomes. can get.

The impurities contained in the second treatment liquid 39 include, for example, first, impurities that were not crushed by the crushing device 20 and were not cut by the cutting device 30, and secondly, crushed by the crushing device 20 and , The contaminants that were not cut by the cutting device 30, thirdly, the impurities that were not crushed by the crushing device 20 and were cut by the cutting device 30, and fourthly, the impurities that were crushed by the crushing device 20 and were cut by the cutting device 30. Includes contaminants cut in. The first treatment liquid 38 containing the first contaminants crushed by the crushing apparatus 20 is allowed to flow into the cutting apparatus 30, and the first contaminants cut are referred to as the second contaminants.

As described above, filamentous or strip-shaped impurities adhere to or become entangled in the equipment of the sewage treatment facility, but it is desirable to cut the hair appropriately because the hair becomes coarse. When the hair is present in the sewage, organic substances, oils and fats, and other hair adhere to the cuticle portion on the surface of the hair. In addition, when these adhere, bacteria propagate. Since the hair is made of enamel-like tissue, it is hard and is not easily biodegraded and remains in the sewage treatment facility. Then, the impurities derived from the hair become coarse and may cause a problem in various facilities.

In the present embodiment, the sewage 10 flows into the crushing device 20 by the inflow means 51 and flows out as the first treatment liquid 38. Next, the first treatment liquid 38 is sent to the cutting device 30 by the water supply means 52, flows into the cutting device 30, and flows out as the second treatment liquid 39 by the outflow means 53. The time for the first treatment liquid 38 flowing out of the crushing device 20 to reach the cutting device 30 is preferably within 60 seconds, preferably 2 to 15 seconds. If it is longer than 60 seconds, the contaminants crushed by the crushing device 20, especially the filaments and strips, may be deformed or re-aggregated into large lumps while reaching the cutting device 30. Crushing by the cutting device 30 becomes difficult. The water supply means 50 between the outflow portion of the crushing device 20 and the inflow portion 36 of the cutting device 30 is not particularly limited, and pipes, water channels, or the like can be used.

(Treatment of the second treatment liquid)
The contaminants contained in the second treatment liquid obtained in the present embodiment may be removed so as not to be contained in the effluent finally discharged from the sewage treatment facility. As a means for removing the sludge, for example, the contaminants can be first extracted from the settling basin as sewage sludge, guided to a sludge storage tank, sent to a sludge treatment facility, and burned.

(Installation location)
The crushing device 20 and the cutting device 30 can be appropriately installed in a sewage treatment facility and a sludge treatment facility. For example, inlets and / or outlets of storage tanks for pumping stations and sludge collection facilities, inlets and outlets for sand basins and screen facilities, inlets for first sedimentation basins, enrichment tanks and digestion tanks, distribution tanks, scum storage It can be installed at the inlet and / or outlet of the tank. In addition, it may be installed at at least one of these installation locations.

In the above-mentioned embodiment, the cutting device 30 is installed on the downstream side of the place where the crushing device 20 is installed, but the following embodiment may be used. An embodiment in which two crushing devices 20 are installed in series along the flow direction of the sewage 10 and a cutting device 30 is installed on the downstream side thereof can be exemplified. Further, an embodiment in which two cutting devices 30 installed in series on the downstream side of the place where the crushing device 20 is installed can be exemplified. In this case, among the cutting devices 30 installed in series, the diameter of the transmission hole 34a of the facing plate 34 provided in the first cutting device 30 on the upstream side is relatively increased, and the second cutting device 30 on the downstream side is used. It is preferable that the diameter of the transmission hole 34a of the facing plate 34 provided is relatively small. When arranged in this way, the contaminants are roughly cut by the first cutting device 30, and then finely cut by the second cutting device 30, so that the impurities can be reliably refined.

(Flow rate)
The sewage 10 flowing into the crushing device 20 and the first treatment liquid 38 flowing into the cutting device 30 may have a flow rate of 10 to 100 m ³ / h and a total solid matter amount (TS) of 0 to 4%. If the flow rate is less than 10 m ³ / h, the processing efficiency is poor, and if it exceeds 100 m ³ / h, a large amount of contaminants flow into these devices and cause clogging. On the other hand, if the total amount of solids (TS) exceeds 4%, the concentration of solids is too high, which causes clogging of these devices.

The sewage of the present embodiment is not particularly limited, but for example, septic tank drainage, agricultural / fishery village drainage, rainwater, factory drainage, workplace drainage, unknown water, underflow water, spring water, groundwater, industrial water, sewage pipe water. , Sewerage trunk water, raw sludge, active sludge, sewage treatment plant and / or process water flowing through each treatment process of sludge treatment facility.

The sewage treatment method and the sewage treatment apparatus disclosed in the present invention are not particularly limited, and can be used in, for example, public sewers, basin sewers, and urban sewage canal sewage treatment facilities.

10 Sewage 20 2-axis crusher 23a Crushing blade 23b Crushing blade 24A Rotating shaft 24B Rotating shaft 30 Cutting device 32 Holder 34 Facing plate 34A Upstream side plane 34a of the first treatment liquid in the facing plate 34a Through hole 35 Cutting blade 38 First treatment liquid 39 Second treatment liquid

The present invention relates to a sewage treatment method and a sewage treatment apparatus.

Conventionally, sewage such as domestic effluent, business establishment effluent, and factory effluent is drained to a sewage pipe, and is collected and treated at a sewage treatment plant via a relay pumping station and a sewer trunk line. The treated water is discharged into rivers and the sea.

The drained sewage includes, for example, plastics, underwear, rags, fibers such as absorbent cotton, and various impurities such as waste cloth, toilet paper, and hair. These contaminants cannot be discharged into rivers or the sea together with the water treated at the sewage treatment plant, for example, they are collected by screen equipment installed in the sand basins of relay pumping stations and sewage treatment plants, and are industrialized. Treated as waste.

In recent years, taking advantage of the effective use of energy and the economies of scale of sewage treatment plants, there is a tendency to consolidate sewage other than conventional sewage at sewage treatment plants and promote treatment. Here, examples of sewage other than conventional sewage include sewage from septic tanks, agricultural / fishery settlement drainage facilities, etc., and these sewage may include food waste, industrial waste, and diaper pieces.

By promoting intensive treatment at this sewage treatment plant, the amount of contaminants flowing into the sewage treatment plant tends to increase.

In a sewage treatment plant, an increase in contaminants causes various problems in the tank (pond) and equipment provided in each process of sewage treatment.

Therefore, in order to increase the amount of contaminants, it is possible to adopt a method of suppressing defects by crushing the contaminants to a suitable size.

Patent Document 1 and Patent Document 2 are disclosed as techniques for crushing contaminants. Patent Document 1 relates to an apparatus provided with a first crushing means, a receiving water tank, and a second crushing means, and is a technique for crushing solid foreign substances such as residue by these crushing means. However, since these crushing means crush the solid foreign matter with a pair of upright crushing units, the crushed material is not cut and extends in a band shape. Then, the crushed material adheres to or gets entangled in the tank (pond) or equipment, causing a problem.

Japanese Patent No. 5336266 Special Table 2012-521285 Special Table 2013-537103

A main problem to be solved by the present invention is to provide a sewage treatment method and a sewage treatment apparatus for crushing and cutting impurities contained in sewage to a suitable size.

Typical aspects of the present invention that have solved the above problems are as follows.

<First aspect>
A crushing step of flowing sewage into a twin-screw crusher and crushing the contaminants contained in the sewage to obtain a first contaminant, and obtaining a first treatment liquid containing the first contaminant.
It has a cutting step of flowing the first treatment liquid into a cutting device, cutting the first contaminant to obtain a second contaminant, and forming a second treatment liquid containing the second contaminant.
The biaxial crusher is
It is a device provided with two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushed while sandwiching the contaminants with these rotating shafts to obtain the first contaminants.
The cutting device intersects the flow direction of the first treatment liquid with the cutting blade held by the holder rotating around the rotation axis in the flow direction of the first treatment liquid in the flow of the first treatment liquid. It is provided with a facing plate having a plurality of through holes, which is provided in the above manner.
In the cutting step, the cutting blade is rotated in a state of facing or in close contact with the facing plate to cut the first contaminant into the second contaminant, and the through hole of the facing plate is permeated. The second treatment liquid is used.
A sewage treatment method characterized by that.

Contaminants contained in sewage can be collected by, for example, a screen equipment installed in a relay pumping station or a sand basin, but impurities that have passed through the screen equipment can be collected in a treatment facility or treatment equipment downstream of the screen equipment. It adheres to or gets entangled in the treatment facility and has a significant effect on the operation of the treatment facility. When the sewage containing the contaminants was allowed to flow into the twin-screw crusher, the contaminants sandwiched between the rotating shafts were crushed, and as a result, the crushed first contaminant and the crushed first contaminant passed through the twin-screw crusher without being crushed. A first treatment liquid containing small-sized impurities is obtained. The thickness of the first contaminant is about the same as the width of the rotating shafts. However, among the first contaminants, there are some that are not thick but are long filaments or strips. Therefore, the first treatment liquid containing the first contaminants is sent to the cutting device, and the cutting blade provided in the cutting device is rotated in a state of being close to or in contact with the facing plate to cut the first contaminants. Then, the contaminants contained in the second treatment liquid are composed of those having a suitable size that have passed through the twin-screw crushing device and the cutting device. Therefore, the treatment facilities and treatment equipment provided downstream, and these It is possible to prevent the burr portion from adhering to or getting entangled.

Of the impurities sent to the cutting device, the impurities having a size that cannot pass through the through hole of the facing plate stay (catch) on the facing plate. The contaminants that have stayed (caught) on the facing plate are cut by the rotation of the cutting blade. The contaminants remaining on the facing plate are cut and permeate through the permeation holes along the sewage stream.

If the contaminants remain attached to the facing plate, depending on the sewage to be treated, the contaminants may gradually accumulate on the facing plate due to the continuous or intermittent inflow of the first treatment liquid, and solidify or enlarge. It may cause blockage of the facing plate. When the cutting blade is rotated in a state of facing or in contact with the facing plate, impurities adhering to the facing plate are scraped off by the cutting blade. As a result, it is possible to prevent impurities from accumulating on the facing plate.

<Second aspect>
The biaxial crushing device crushes the contaminants into first contaminants having a thickness of 10 mm or less.
Examples of the cutting device include cutting the first contaminant into a second contaminant having a length of 50 mm or less.

Since these devices can obtain impurities having a thickness of 10 mm or less and a length of 50 mm or less, the obtained impurities adhere to and become entangled with the processing facilities and equipment provided downstream and the burrs thereof. It has the effect that it can be further suppressed.

<Third aspect>
The cutting device has an inflow portion through which the first treatment liquid flows.
An embodiment in which the facing plate is provided so that the angle formed by the facing plate and the inflow direction of the first processing liquid in the inflow portion of the cutting device is an acute angle can be mentioned.

Since the facing plate has an acute angle with respect to the flow direction of the first treatment liquid in the inflow portion of the cutting device, the through hole also has an acute angle. When the facing plate is provided in this way, it becomes difficult for impurities to pass through the through hole, and it becomes easy for the contaminants to be caught and stayed on the facing plate. Not only relatively long impurities but also relatively small impurities can easily stay on the facing plate, so that the impurities can be cut more finely.

<Fourth aspect>
An embodiment in which the time for the first treatment liquid flowing out of the twin-screw crushing device to reach the cutting device is within 60 seconds can be mentioned.

The first treatment liquid contains the first contaminants crushed by a crusher. If the first contaminant is left uncut for a while, the first contaminant may be deformed or re-aggregated into a large mass, making it difficult to cut with the cutting device. Therefore, by setting the time for the first treatment liquid to reach the cutting device within 60 seconds, there is an effect of preventing deformation and reaggregation of contaminants and making it easy to cut with the cutting device. ..

<Fifth aspect>
A sewage treatment device that crushes and cuts impurities contained in the inflowing sewage.
The sewage treatment device
A twin-screw crusher that crushes impurities into the first contaminants and obtains a first treatment liquid containing the first contaminants.
It comprises a cutting device for cutting the first contaminant to obtain a second contaminant and obtaining a second treatment liquid containing the second contaminant.
The biaxial crushing device includes two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushes the contaminants while sandwiching them between the rotating shafts to obtain the first contaminants. Yes,
The cutting device intersects the flow direction of the first treatment liquid with a cutting blade held by a holder that rotates around the rotation axis in the flow direction of the first treatment liquid in the flow of the first treatment liquid. The cutting blade is rotated in a facing state in close proximity to or in contact with the facing plate to cut the first contaminant and the second contamination. It is a thing,
It can be mentioned that the sewage treatment apparatus is characterized by this.

According to the present invention, by crushing and finely cutting impurities contained in sewage, it is possible to suppress problems such as adhesion to sewage treatment facilities and treatment equipment, entanglement, and blockage.

It is a figure which shows the biaxial crushing apparatus. It is a figure which shows the twin-screw crusher of another embodiment. It is explanatory drawing which sewage passes through a group of crushing disks. It is explanatory drawing of the cutting device. It is a figure which shows the main part of crushing of a cutting apparatus. It is a figure which shows an example of the facing plate. It is a figure which shows another form of the cutting apparatus. It is a figure which shows the processing flow. It is explanatory drawing of the angle formed by the facing plate and the inflow direction of the 1st processing liquid in the inflow part.

A mode for carrying out the present invention will be described. The embodiment of the present invention is an example of the present invention.

(Sewage treatment facility)
Since sewage drained from homes and business establishments is sewage, it flows into sewage pipes and sewer trunk lines, and also flows into sewage treatment plants via relay pumping stations. The sewage that has flowed into the sewage treatment plant is discharged to the outside of the system through, for example, a sand basin, a first settling basin, a reaction tank, a final settling basin, and a chlorine-mixed area. The sludge (raw sludge) that settled on the bottom of the pond in the first settling basin and the activated sludge that settled on the bottom of the pond in the final settling basin are temporarily stored in the sludge storage tank and mixed. Then, the volume of this mixed sludge is reduced by concentration, dehydration, incineration, etc. at the sludge treatment facility. Each treatment facility such as the first settling basin, reaction tank, final settling basin, and chlorine-mixed area is equipped with various mechanical equipment such as measuring equipment, agitator, and sludge scraper. The sludge sent to the sludge treatment facility is treated, for example, through a concentration tank, a digestion tank, a dehydrator, and an incinerator.

(sewage)
Conventionally, sewage was mainly composed of domestic wastewater, industrial wastewater, and business site wastewater. In addition, plants such as branches and leaves, stems and grass, soil, etc. may also be mixed in the sewage. In recent years, taking advantage of the economies of scale of sewage treatment plants, there is a tendency to incinerate sludge generated by consolidating septic tank wastewater, agricultural wastewater, food waste, diapers, etc. into the sewerage system to convert it into energy. However, if these are allowed to flow into a sewage treatment plant together with sewage and are intensively treated, the amount of contaminants will also increase.

(Contaminants)
Contaminants contained in sewage of sewage treatment facilities (for example, pumping stations, storage pipes, sewage treatment plants, sludge treatment facilities, etc.) include plastics, underwear, rags, fibers such as defatted cotton, waste cloth, toilet paper, and hair. , Garbage, oil balls, and diaper pieces can be exemplified, but are not limited thereto.

Contaminants can be collected by the screen equipment provided in the pumping station or sand basin, but in general, the forms of impurities (for example, size and length) vary, so they are collected by the same screen equipment. Some are transparent without being used. If sewage containing contaminants flows into the sewage treatment plant, especially each treatment facility after the first settling basin, troubles such as malfunction of the equipment due to contamination of the equipment installed in each treatment facility. In some cases, it will hinder the operation of the entire sewage treatment plant. In addition, a heat exchanger may be provided to heat the sludge when the sludge is reduced in volume in the digestion tank, but impurities get entangled in the piping inside the heat exchanger and block the heat exchanger. It may cause a problem.

In order to reduce such troubles and malfunctions as much as possible, it is advisable to take measures to eliminate adhesion and entanglement due to contaminants on equipment and piping. For example, measures can be taken to reduce the size by crushing or cutting impurities. In order to crush or cut the contaminants, known means can be taken without particular limitation, but it is preferable to equip the sewage treatment facility with a crushing device or a cutting device.

(Crushing device)
The structure of the crusher is not limited, but a crusher having a plurality of rotating shafts (for example, a biaxial shear crusher or a multiaxial shear crusher) can be used. The biaxial crushing device 20 will be described below as an example. As a biaxial crushing device, an example may be exemplified which is provided with two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushed while sandwiching the contaminants between these rotating shafts to obtain the first contaminant. .. The biaxial crusher 20 has two substantially parallel first rotating shafts 24A and second rotating shafts 24B that rotate around a shaft core. The first rotating shaft 24A and the second rotating shaft 24B may be rotated by a gear motor or the like. It is preferable to use a form in which the first rotating shaft 24A is provided with a plurality of crushing disks 23A provided with a plurality of crushing blades 23a protruding outward in the radial direction in the axial direction. It is preferable that at least one crushing blade 23a is provided on the outer peripheral portion of the crushing disk 23A. The positions of the crushing blades 23a of the crushing disk 23A group along the axis direction may be different for each crushing disk 23A in the direction around the axis, or may be arranged in a row. Similarly, the second rotating shaft 24B is also provided with a plurality of crushing disks 23B provided with a plurality of crushing blades 23b protruding outward in the radial direction in the axial direction. There is at least one crushing blade 23b on the outer peripheral portion, and the position of the crushing blade 23b of the crushing disk 23B along the axis direction may be different for each crushing disk 23B in the axial direction, or in a row. You may line up in. The crushing disk 23A group and the crushing disk 23B group may be arranged at intervals along the axis, or adjacent crushing disks may be arranged so as to be in close contact with each other. The plane direction of each of the crushing disk 23A and the crushing disk 23B is substantially perpendicular to the rotation axis direction. The structure may be such that the first rotating shaft 24A having the crushing blade 23a and the second rotating shaft 24B having the crushing blade 23b are arranged in the casing 25. In this structure, the sewage 10 may flow so that the sewage 10 flows into the crushing device 20 from the inflow portion 22 provided in the casing 25 and the first treatment liquid 38 flows out from the outflow portion 21. It is preferable that the crushing disk 23A group provided on the first rotating shaft 24A and the crushing disk 23B group provided on the second rotating shaft 24B are separated from each other by 7 to 10 mm. Further, both rotation shafts 24A and 24B may be arranged in a direction intersecting the inflow direction of the sewage 10.

The casing 25 does not necessarily have to be provided, and a biaxial crushing device 20 that does not have the casing 25 may be provided in a water channel or a pipe through which sewage flows. Further, all of the sewage 10 may be sent to the twin-screw crusher 20, or a part of the sewage 10 may be sent, but it is preferable to send all of the sewage 10.

When the sewage 10 is made to flow into the crushing device, the impurities contained in the sewage 10 are crushed by the crushing blade. Then, the treatment liquid 38 containing the crushed contaminants (hereinafter, also referred to as “first treatment liquid 38”) is discharged from the crusher. The relatively small contaminants are either appropriately crushed by the crusher or passed through without being crushed. In addition, relatively large contaminants may be crushed or compressed to the thickness of the distance between the rotating shafts to form a thread-like or strip-like form. The thread-like or strip-shaped morphology contained in the first treatment liquid 38 has, for example, a thickness of about 10 mm or less, but there are also those having a length of, for example, more than 50 cm, and these filament-like or strip-shaped morphologies are There is a risk of causing problems such as sticking to or entanglement with equipment installed downstream of the processing process. The contaminants contained in the first treatment liquid 38 that have passed through the crushing apparatus include crushed first contaminants and contaminants that have passed between the rotating shafts without being crushed.

(Cutting device)
As the cutting device, the configuration of the cutting device is not particularly limited as long as it is crushed by a cutting blade, but the cutting device 30 shown in the present embodiment can be preferably used for cutting contaminants. .. Further, the cutting device disclosed in Patent Document 2 and Patent Document 3 and the product "Rotacut" sold by Tsukishima Technomente Service Co., Ltd. may be used. The cutting device 30 shown in the present embodiment intersects the cutting blade 35 held by the holder 32 that rotates around the rotation axis of the flow direction 38b of the first treatment liquid 38 and the flow direction 38b of the first treatment liquid 38. It is provided with a facing plate 34 having a plurality of through holes 34a provided. The cutting blade 35 may have a cutting blade main body as a blade, or may have a rotary blade 35b provided with a cutting edge 35a. The contaminants are sandwiched between the cutting blade 35 and the facing plate 34, and are cut by receiving a shearing force. Explaining with reference to FIG. 4, the cutting device 30 is provided with a cutting blade 35 (rotary blade 35b and a cutting edge 35a provided on the rotary blade) facing the facing plate 34 surface. A plurality of transmission holes 34a penetrating the facing plate 34 are provided on the surface of the facing plate 34. The facing plate 34 may or may not include a blade. When the blade is provided, for example, the blade may be provided on the upstream side surface 34A of the first treatment liquid 38 in the facing plate 34, or the edge of the transmission hole may be formed in a blade shape. The form of the facing plate 34 may be a net-like one, or a so-called net blade in which the net itself is a cutting edge. Further, a perforated plate, a cribriform plate, or a lattice plate may be used, and a form in which the edge of the through hole in the perforated plate, the cribriform plate, or the lattice plate is formed by the cutting edge can be presented. Further, as shown in FIG. 6, it may be in the form of a facing plate in which transmission holes 34a having a substantially quadrangular shape or a substantially triangular shape are arranged while gradually expanding from the center to the outside in a spiral shape.

The cutting blade 35 may be installed on the upstream side of the facing plate 34. The contaminants are cut by the shearing force generated between the facing plate 34 and the cutting blade 35 when passing through the through hole 34a of the facing plate 34, but when arranged in this way, the first one flowing through the cutting device 30. Of the impurities contained in the treatment liquid, the impurities remaining (or caught) on the facing plate 34 are preferably cut by the rotating cutting blade 35.

The cutting blade 35 is provided in a rotatable holder 32, and when the holder 32 rotates, the cutting blade 35 rotates along the upstream plane 34A. The cutting blade 35a and the upstream plane 34A of the facing plate 34 rotate in close or in contact with each other.

When the cutting blade 35 is in contact with the upstream flat surface 34A of the facing plate 34, the rotation of the cutting blade 35 causes the cutting blade 35 to scrape off the contaminants adhering to the upstream flat surface 34A, and the contaminants are surely removed. It is suitable for being cut into. As an example of a means for maintaining the state in which the cutting edge 35a of the cutting blade 35 is in contact with the upstream flat surface 34A, the holder 32 provided in the cutting blade 35 is moved from the cutting blade 35 toward the facing plate 34 (biasing direction) 42. The means 33a for urging the vehicle can be mentioned. As a result, the cutting blade 35 can rotate while being pulled (biased) in the urging direction 42 and in contact with the upstream plane 34A of the facing plate 34. As the urging means 33a, known means such as a spring and a hydraulic cylinder can be used. The holder 32 may be rotated by a gear motor or the like.

The cutting blade 35 can be formed in the shape of a rotary blade. In this case, the number of blades can be set as appropriate. For example, it may be one sheet, or it may be any number of 2 to 8 sheets such as 2, 3, 4, 5, 5, and 8.

The shape of the transmission hole 34a of the facing plate 34 is not particularly limited, and may be, for example, a polygonal shape consisting of a substantially circular shape, a substantially triangular shape to a substantially hexagonal shape, a grid shape, a net shape, or the like. The width (or diameter) of the transmission hole 34a can be appropriately set, and is preferably 10 to 40 mm because impurities are appropriately cut and penetrate the transmission hole 34a.

The cutting device 30 of the present embodiment includes an inflow portion 36 into which the first treated water 38 flows in and an outflow portion 37 in which the water that has passed through the facing plate 34, that is, the second treated water 39 flows out. The facing plate 34 is provided so as to intersect the inflow direction 38a of the first treated water 38 in the inflow portion 36. The angle θ formed by the facing plate 34 (that is, the inclination 34r of the facing plate 34 surface) and the inflow direction 38a of the first treatment liquid 38 in the inflow portion 36 of the cutting device 30 may be a right angle, but as shown in FIG. It is preferable to make the angle sharp. In particular, it is preferable that the angle θ when the angle is acute is 15 ° or more. When the angle is sharp, the contaminants are easily caught by the facing plate 34 and stay there, so that the amount of contaminants to be cut increases, and as a result, the second treatment liquid containing a large amount of the contaminants cut short is discharged from the cutting device 30. .. When the angle θ is smaller than 15 °, the inflow direction 38a of the first treatment liquid and the plane of the facing plate 34 become close to parallel, and the speed at which the first treatment liquid permeates the surface of the facing plate 34 decreases hydraulically. The flow rate of the first treatment liquid that permeates the facing plate 34 is reduced, and as a result, the amount of sewage treated per unit time is reduced.

The facing plate 34 and the cutting blade 35 can be provided in the casing. The casing can be composed of two chambers, and a facing plate 34 may be provided so as to partition the first chamber 40 and the second chamber 41. The first chamber is provided with the above-mentioned cutting blade 35 and the inflow portion 36, and the second chamber is provided with the outflow portion 37. In this case, the holder 32 provided in the cutting blade 35 may be extended toward the second chamber and arranged so as to extend to the urging means 33a provided in the upper part of the second chamber. The first treatment liquid 38 that has flowed into the first chamber passes through the facing plate 34 and is guided to the second chamber, and is discharged from the outflow portion 37 as the second treatment liquid 39.

Further, a cutting device having a facing plate 34 and a cutting blade 35 may be provided in a water channel or a pipe through which the first treatment liquid 38 flows without providing a casing. In this case, needless to say, the cutting blade 35 is arranged on the upstream side and the facing plate 34 is arranged on the downstream side of the flow direction of the first treatment liquid 38.

The first treatment liquid 38 may be completely permeated through the facing plate 34 or a part thereof, but it is preferable that all of the first treatment liquid 38 is permeated.

The impurities contained in the first treatment liquid 38, particularly the filamentous material and the strip-shaped material, are cut by receiving a cutting force (shearing force) by the rotatable cutting blade 35 and / or the facing plate 34. Therefore, most of the impurities contained in the second treatment liquid 39 have a thickness of 10 mm or less and a length of 50 mm or less, so that they may adhere to or get entangled with various facilities provided on the downstream side of the cutting device. Can be suppressed.

As another embodiment, the sewage 10 can be directly sent to the cutting device 30 without being sent to the crushing device 20. However, in this "other embodiment", relatively large contaminants contained in the sewage stay on the facing plate 34 one after another, resulting in blockage of the cutting device 30. Therefore, when only the cutting device 30 is provided without providing the crushing device 20, it is preferable to install it in a sewage treatment facility where there are relatively few large impurities. For example, it is preferable to first install the cutting device 30 in the drawn sludge pipe of the settling basin, the inflow pipe and the outflow pipe of each of the concentration tank and the digestion tank.

Explaining another embodiment of the cutting device with reference to FIG. 7, the cutting device 130 is provided with a cutting blade 135 (a blade 135a attached to the rotary blade 135b) on the side facing the facing plate 134. .. The facing plate 134 is provided with a plurality of through holes penetrating the facing plate 134. The cutting blade 135 is provided with a holder 132 that is rotated by a gear motor 152 or the like, and the cutting blade 135 is rotated along the surface of the facing plate 134 by the rotation of the holder 132. The cutting blade 135 and the upstream side surface of the first treatment liquid 38 on the facing plate 134 are in contact with each other. A means 133 is provided for urging the cutting blade 135 in the direction (biasing direction) from the cutting blade 135 toward the facing plate 134 in order to bring the cutting blade 135 into contact with the facing plate 134. Further, the contaminants that cannot be completely cut and cannot pass through the facing plate 134 can be taken out from the take-out unit 151 provided in the lower part of the cutting device 130. Further, when the operation of the main body is stopped, the upper portion of the cutting device 130 (above the facing plate 134) can be moved counterclockwise with respect to the paper surface to open the fulcrum shaft 100 provided in the main body 130. Then, the inside of the casing 136 can be visually recognized from above, and the maintenance inside the main body can be easily performed. When the cutting device 130 is operated with the upper portion of the cutting device 130 closed, the first treatment liquid 38 sent to the cutting device 130 permeates through the facing plate 134, and as a result, the second treatment liquid 39 becomes. can get.

The impurities contained in the second treatment liquid 39 include, for example, first, impurities that were not crushed by the crushing device 20 and were not cut by the cutting device 30, and secondly, crushed by the crushing device 20 and , The contaminants that were not cut by the cutting device 30, thirdly, the impurities that were not crushed by the crushing device 20 and were cut by the cutting device 30, and fourthly, the impurities that were crushed by the crushing device 20 and were cut by the cutting device 30. Includes contaminants cut in. The first treatment liquid 38 containing the first contaminants crushed by the crushing apparatus 20 is allowed to flow into the cutting apparatus 30, and the first contaminants cut are referred to as the second contaminants.

As described above, filamentous or strip-shaped impurities adhere to or become entangled in the equipment of the sewage treatment facility, but it is desirable to cut the hair appropriately because the hair becomes coarse in particular. When the hair is present in the sewage, organic substances, oils and fats, and other hair adhere to the cuticle portion on the surface of the hair. In addition, when these adhere, bacteria propagate. Since the hair is made of enamel-like tissue, it is hard and is not easily biodegraded and remains in the sewage treatment facility. Then, the impurities derived from the hair become coarse and may cause a problem in various facilities.

In the present embodiment, the sewage 10 flows into the crushing device 20 by the inflow means 51 and flows out as the first treatment liquid 38. Next, the first treatment liquid 38 is sent to the cutting device 30 by the water supply means 52, flows into the cutting device 30, and flows out as the second treatment liquid 39 by the outflow means 53. The time required for the first treatment liquid 38 flowing out of the crushing device 20 to flow into the cutting device 30 is preferably within 60 seconds, preferably 2 to 15 seconds. If it is longer than 60 seconds, the contaminants crushed by the crushing device 20, especially the filaments and strips, may be deformed or re-aggregated into large lumps while reaching the cutting device 30. Crushing by the cutting device 30 becomes difficult. The water supply means 50 between the outflow portion of the crushing device 20 and the inflow portion 36 of the cutting device 30 is not particularly limited, and pipes, water channels, or the like can be used.

(Treatment of the second treatment liquid)
The contaminants contained in the second treatment liquid obtained in the present embodiment may be removed so as not to be contained in the effluent finally discharged from the sewage treatment facility. As a means for removing the sludge, for example, the contaminants can be first extracted from the settling basin as sewage sludge, guided to a sludge storage tank, sent to a sludge treatment facility, and burned.

(Installation location)
The crushing device 20 and the cutting device 30 can be appropriately installed in a sewage treatment facility and a sludge treatment facility. For example, inlets and / or outlets of storage tanks for pumping stations and sludge collection facilities, inlets and outlets for sand basins and screen facilities, inlets for first sedimentation basins, enrichment tanks and digestion tanks, distribution tanks, scum storage It can be installed at the inlet and / or outlet of the tank. In addition, it may be installed at at least one of these installation locations.

In the above-mentioned embodiment, the cutting device 30 is installed on the downstream side of the place where the crushing device 20 is installed, but the following embodiment may be used. An embodiment in which two crushing devices 20 are installed in series along the flow direction of the sewage 10 and a cutting device 30 is installed on the downstream side thereof can be exemplified. Further, an embodiment in which two cutting devices 30 installed in series on the downstream side of the place where the crushing device 20 is installed can be exemplified. In this case, among the cutting devices 30 installed in series, the diameter of the transmission hole 34a of the facing plate 34 provided in the first cutting device 30 on the upstream side is relatively increased, and the second cutting device 30 on the downstream side is used. It is preferable that the diameter of the transmission hole 34a of the facing plate 34 provided is relatively small. When arranged in this way, the contaminants are roughly cut by the first cutting device 30, and then finely cut by the second cutting device 30, so that the impurities can be reliably refined.

(Flow rate)
The sewage 10 flowing into the crushing device 20 and the first treatment liquid 38 flowing into the cutting device 30 may have a flow rate of 10 to 100 m ³ / h and a total solid matter amount (TS) of 0 to 4%. If the flow rate is less than 10 m ³ / h, the processing efficiency is poor, and if it exceeds 100 m ³ / h, a large amount of contaminants flow into these devices and cause clogging. On the other hand, if the total amount of solids (TS) exceeds 4%, the concentration of solids is too high, which causes clogging of these devices.

The sewage of the present embodiment is not particularly limited, but for example, septic tank drainage, agricultural / fishery village drainage, rainwater, factory drainage, workplace drainage, unknown water, underflow water, spring water, groundwater, industrial water, sewage pipe water. , Sewerage trunk water, raw sludge, active sludge, sewage treatment plant and / or process water flowing through each treatment process of sludge treatment facility.

The sewage treatment method and the sewage treatment apparatus disclosed in the present invention are not particularly limited, and can be used in, for example, public sewers, basin sewers, and urban sewage canal sewage treatment facilities.

10 Sewage 20 2-axis crusher 23a Crushing blade 23b Crushing blade 24A Rotating shaft 24B Rotating shaft 30 Cutting device 32 Holder 34 Facing plate 34A Upstream side plane 34a of the first treatment liquid in the facing plate 34a Through hole 35 Cutting blade 38 First treatment liquid 39 Second treatment liquid

Claims (5)

A crushing step of flowing sewage into a twin-screw crusher and crushing the contaminants contained in the sewage to obtain a first contaminant, and obtaining a first treatment liquid containing the first contaminant.
It has a cutting step of flowing the first treatment liquid into a cutting device, cutting the first contaminant to obtain a second contaminant, and forming a second treatment liquid containing the second contaminant.
The biaxial crushing device is a device that includes two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushes the contaminants while sandwiching them between the rotating shafts to obtain the first contaminants. Yes,
The cutting device intersects the flow direction of the first treatment liquid with the cutting blade held by the holder rotating around the rotation axis in the flow direction of the first treatment liquid in the flow of the first treatment liquid. It is provided with a facing plate having a plurality of through holes, which is provided in the above manner.
In the cutting step, the cutting blade is rotated in a state of facing or in close contact with the facing plate to cut the first contaminant into the second contaminant, and the through hole of the facing plate is permeated. The second treatment liquid is used.
A sewage treatment method characterized by that. The biaxial crushing device crushes the contaminants into first contaminants having a thickness of 10 mm or less.
The cutting device cuts the first contaminant into a second contaminant having a length of 50 mm or less.
The sewage treatment method according to claim 1. The cutting device has an inflow portion through which the first treatment liquid flows.
The facing plate is provided so that the angle formed by the facing plate and the inflow direction of the first treatment liquid in the inflow portion is an acute angle.
The sewage treatment method according to claim 1. The time for the first treatment liquid flowing out of the twin-screw crusher to reach the cutting device is within 60 seconds.
The sewage treatment method according to claim 1. A sewage treatment device that crushes and cuts impurities contained in the inflowing sewage.
The sewage treatment device
A twin-screw crusher that crushes impurities into the first contaminants and obtains a first treatment liquid containing the first contaminants.
It comprises a cutting device for cutting the first contaminant to obtain a second contaminant and obtaining a second treatment liquid containing the second contaminant.
The biaxial crushing device includes two rotating shafts arranged in parallel having a crushing blade on the peripheral portion, and crushes the contaminants while sandwiching them between the rotating shafts to obtain the first contaminants. Yes,
The cutting device intersects the flow direction of the first treatment liquid with a cutting blade held by a holder that rotates around the rotation axis in the flow direction of the first treatment liquid in the flow of the first treatment liquid. The cutting blade is rotated in a facing state in close proximity to or in contact with the facing plate to cut the first contaminant and the second contamination. It is a thing,
A sewage treatment device characterized by this.

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