JP2002282721A - Sludge crushing apparatus and apparatus for treating organic sewage by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive sludge crushing apparatus whose maintenance is made easy and to provide an apparatus for treating organic sewage by using the sludge crushing apparatus. SOLUTION: This sludge crushing apparatus is provided with a rotary disk rotating at >= about 30 m/second peripheral velocity, a driving means for driving the rotary disk and preferably a fixed disk which is arranged oppositely to the rotary disk and has a sludge sucking port in the center so that the sludge is crushed mainly by the rotational shearing force of the rotary disk while the disk clearance between the rotary disk and the fixed disk is set to be >=about 5 mm. This organic sewage treating apparatus is constituted so that at least a part of the sludge separated from the treated liquid treated by a biologically treating means is crushed by using the sludge crushing apparatus and at least a part of the crushed sludge is returned to the biologically treating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sludge crushing apparatus for crushing sludge generated by biological treatment of organic wastewater, and an organic wastewater treatment apparatus using the same.

[0002]

2. Description of the Related Art At present, most of organic wastewater such as municipal wastewater and organic industrial wastewater is treated by an activated sludge method, but a large amount of excess sludge is generated. Excess sludge is a portion of the activated sludge that has been treated in the activated sludge reaction tank, introduced into a final sedimentation basin, etc. It is mainly composed of microorganisms that have grown using dissolved organic matter in sewage as a substrate, and protozoa that have predated and grown on microorganisms.

The amount of surplus sludge discharged is about 2 million tons / year in terms of dry weight, and about 55% of it is landfilled at the final disposal site after dehydration or incineration. Due to the absolute shortage of landfills, there is a strong social demand for landfill reduction.

[0004] Disposal methods such as energy recovery, material conversion, green space reduction, and volume reduction have been studied and put into practical use as measures to effectively use or reduce excess sludge. There is a method for treating organic wastewater in which sludge discharged as sludge is solubilized and returned to an activated sludge tank.

[0005] In other words, the digestion of organic sludge in the activated sludge tank is performed by producing water and carbon dioxide through solubilization and hydrolysis, but the intracellular level of proteins, nucleic acids, lipids, carbohydrates and the like is increased. Since the elution of molecular substances and the reduction of molecular weight by hydrolysis of these substances are rate-determining and require a long digestion period, efficient digestion cannot be performed even if the sludge is returned to the activated sludge tank as it is. Therefore, a solubilization device is provided,
This is a powerful organic wastewater treatment method that improves digestion efficiency by solubilizing biodegradable organic matter in sludge and significantly reduces excess sludge discharged outside the apparatus.

[0006] Such solubilization techniques include high energy crushing methods such as ultrasonic crushing, chemical decomposition methods such as ozone oxidation, and mechanical crushing methods using a homogenizer or a mill.
Various researches and developments have been carried out, for example, a method of oxidizing ozone, aerating the same in an aeration tank, and returning solid-liquid separated sludge to a biological treatment apparatus (Japanese Patent Laid-Open No. 10-156381); Anaerobic digestion treatment by disrupting the cell membrane of Example 1 and crushing with a wet mill (Japanese Patent Application Laid-Open No. 02-211297).
No.) are disclosed.

However, the method using ultrasonic waves and ozone has a problem that these generators are separately required and thus are expensive, and a problem that the maintenance cost of the apparatuses is increased. The mechanical crushing by a homogenizer or a mill has a problem that the processing efficiency is low and the cost is high because the apparatus is complicated and large.

Further, as a technique for solving the above problem,
A fixed blade fixed to the inner peripheral surface and a rotary blade for crushing sludge in cooperation with the fixed blade are provided, and a gap between the fixed blade and the rotary blade is 1 mm.
Hereinafter, a sludge crushing apparatus (JP-A-2000-343098), which is preferably set to about 0.1 to 0.5 mm, is disclosed. However, the fixed blade and the rotary blade have a complicated structure. These precision processes are required to reduce the gap between the devices, and the cost is high, and the maintenance of the apparatus requires skill.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described situation relating to a sludge crushing apparatus for crushing sludge generated by biological treatment of organic wastewater, and is easy to maintain and manage. It is an object of the present invention to provide an inexpensive sludge crushing apparatus and an organic sewage treatment apparatus using the same.

[0010]

In order to achieve the above-mentioned object, a sludge crushing apparatus of the present invention is a sludge crushing apparatus for crushing sludge generated by biological treatment of organic sewage, which rotates at a high speed. A sludge crushing apparatus comprising a rotating disk and driving means for driving the rotating disk, and mainly crushing sludge by a rotating shear force of the rotating disk. The rotating disk preferably has a high speed at a peripheral speed of about 30 m / s or more. It is a rotating disk that rotates.

Further, the sludge crushing apparatus of the present invention further comprises a fixed disk opposed to the rotating disk and having a sludge suction port at a central portion, wherein the fixed disk is provided with a predetermined disk gap with the rotating disk. Preferably, the predetermined disk gap is a sludge crushing device having a diameter of about 5 mm or more.

When the fixed disk is further provided, it is desirable to further include a disk gap adjusting means for adjusting the disk gap.

Further, in the sludge crushing apparatus of the present invention, the rotating disk may be a rotating disk having a rough disk surface.

[0014] The sludge crushing apparatus of the present invention further comprises a heating means for heating the sludge in the sludge crushing apparatus, and the heating means keeps the temperature of the sludge at about 50 ° C or higher. be able to.

The organic wastewater treatment apparatus of the present invention comprises a biological treatment means for biologically treating organic wastewater and a solid-liquid separation for solid-liquid separation of the treatment liquid treated by the biological treatment means. Means, and sludge crushing means for crushing at least a part of the separated sludge separated by the solid-liquid separation means, such that at least a part of the sludge crushed by the sludge crushing means is returned to the biological treatment means. In the treated organic sewage treatment apparatus, the sludge crushing means is an organic sewage treatment apparatus constituted by the sludge crushing apparatus of the present invention.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present inventors have paid attention to the generation of excess sludge, which is the biggest drawback of the activated sludge method, which is responsible for most of the treatment of organic wastewater such as municipal sewage and organic industrial wastewater.
For many years, we have been working on research on the reduction of excess sludge and the solubilization technology as a pretreatment for its recycling.

As described above, the present invention has been made based on the research results that the present inventors have worked diligently,
Aiming at effective treatment and recycling of a large amount of excess sludge, which has become a major problem in the organic sludge treatment system using the activated sludge method, it provides an easy-to-maintain and low-cost sludge crusher, It is an object of the present invention to provide an organic wastewater treatment apparatus using the apparatus.

The present inventor pays attention to solubilization of sludge using a rotating disk, which is one of mechanical crushing methods that can be expected to simplify maintenance and reduce costs, and details thereof will be described in Examples described later. Conducted extensive and detailed experimental studies and found that sludge can be effectively solubilized with a simple device by crushing sludge mainly by the rotational shear force of a rotating disk that rotates at high speed, and completed the present invention. It was made.

That is, the conventional solubilization technique using a rotating disk is disclosed in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 2000-343098. ) And a fixed disk ("fixed blade" in Japanese Patent Laid-Open No. 2000-343098), mainly because the sludge is solubilized by rubbing between the two disks or cutting between the two disks. Although the gap between the disks has been set as small as possible (or the disks are brought into contact with each other) to promote the solubilization of the sludge. When used, it was found that the solubilization hardly depended on the disk gap.

This is because rotating the rotating disk at a high speed causes a rotating shear force sufficient to crush sludge on the rotating disk surface, while a rotating speed gradient that generates a rotating shear force capable of crushing the sludge is defined by a rotating speed gradient. This is because it is formed only near the disk surface.

As described above, the sludge crushing apparatus of the present invention is provided with the rotating disk rotating at a high speed and the driving means for driving the rotating disk, and is extremely simple in that the sludge is crushed mainly by the rotating shear force of the rotating disk. A simple apparatus and the need for precision machining of the rotating disk are not required, so that it is possible to provide a low-cost sludge crushing apparatus that is easy to maintain and manage.

Although the rotating disk is not particularly limited to the present invention, it is preferable that the rotating disk is rotated at a high speed at a peripheral speed of about 30 m / s or more. It takes a long time to obtain a good solubilization. If the peripheral speed is increased, solubilization is promoted, so there is no particular upper limit on the peripheral speed.However, the required power increases and the size of the apparatus increases. It reaches the boiling point of 100 ° C, causing problems such as sludge condensing and making crushing difficult.

[0023] The sludge crushing apparatus of the present invention may further comprise a fixed disk opposed to the rotating disk and having a sludge suction port at the center, and the fixed disk may be configured by providing a predetermined disk gap with the rotating disk. The fixed disk forms a flow such that the sludge flowing in the outer peripheral direction of the rotating disk due to the centrifugal force of the rotating disk flows again into the center of the rotating disk through the sludge suction port of the fixed disk. That is, the fixed disk is effective for uniformly solubilizing the sludge in the sludge crushing tank.

In the sludge crushing apparatus of the present invention further provided with such a fixed disk, a suitable disk gap should be determined by the diameter of the rotating disk to be used, the rotation speed, the properties of the sludge to be treated, and the like. Although the present invention is not limited thereto, it is preferably about 5 mm or more. Even if the gap between both disks is further reduced, promotion of solubilization cannot be expected, and in some cases, the flow of sludge between both disks may be reduced. Problems such as restrictions arise.

When further providing a fixed disk,
By further providing the disk gap adjusting means for adjusting the disk gap, the disk gap can be suitably adjusted according to the properties of the sludge to be actually treated, and the present invention can be implemented more effectively. .

As described above, the sludge crushing apparatus of the present invention mainly crushes sludge by the rotational shearing force of the rotating disk. By making the disk surface of the rotating disk rough, the friction of the disk surface is reduced. In order to increase the force or increase the surface area of the disk surface, the rotational shear force required for crushing the sludge can be more effectively applied to the sludge.

The sludge crusher further comprises means for heating the sludge in the sludge crushing apparatus.
Starting the crushing process after heating to ℃ or more, further, by heating and maintaining the temperature of the sludge to about 50 ℃ or more during the crushing process, denatures the cell membrane of microorganisms constituting the sludge,
Crushing can be performed more effectively.

As the heating means, known techniques such as a steam jacket and a heater can be used, and the type of the heating means or the form of attachment does not limit the present invention at all.

As described above, the sludge crushing apparatus of the present invention is provided with a rotating disk that rotates at a high speed, and a drive unit that drives the rotating disk, and is an extremely simple method of crushing sludge mainly by the rotational shear force of the rotating disk. The present invention enables the provision of a simple and low-cost sludge crushing apparatus which is easy to maintain and manage, since it does not require precision machining of the rotating disk.

In the organic wastewater treatment apparatus of the present invention, the organic wastewater is subjected to biological treatment in a biological treatment means, for example, an activated sludge tank, and is propagated using dissolved organic matter in the wastewater as a substrate. The treated liquid containing the microorganisms and the protozoa predated and propagated by the microorganisms is separated by solid-liquid separation means, for example, a final sedimentation basin, and at least a part of the obtained separated sludge is crushed by the sludge crushing apparatus of the present invention. , At least a part of which is returned to the original biological treatment means as a solubilized organic nutrient, and is efficiently digested in the activated sludge tank.

That is, according to the apparatus for treating organic sewage of the present invention, by including the sludge crushing apparatus of the present invention, the apparatus for treating organic sewage can greatly reduce the volume of excess sludge. Can be provided as an easy-to-maintain and low-cost device.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in detail below, focusing on experimental studies on solubilization of sludge using a rotating disk performed by the inventor.

First, the experimental apparatus used will be described with reference to FIGS. 1, 2 and 3.

FIG. 1 is a schematic configuration diagram showing the configuration of an experimental apparatus used in the experimental study of the present invention, FIG. 2 is a photograph thereof, a photograph before sludge is charged, and FIG. It is a photograph of. In addition, as shown in FIGS. 2 and 3, this experimental device was used to observe the crushing state from the outside.
The cylindrical part of the crushing tank containing a rotating disk and the like is made of transparent acrylic.

The experimental apparatus comprises a rotating disk, a motor for driving the rotating disk, a fixed disk facing the rotating disk, a crushing tank containing a rotating disk, etc., as shown in FIGS. It has a very simple structure, and the sludge sucked from the upper fixed disk inlet passes between the two disks by centrifugal force, and during that time, mainly by the rotational shear force of the rotating disk that rotates at high speed Crush sludge, batch (batch)
It is a rotating disk type device.

The rotating disk is a stainless steel disk having a diameter of 200 mm, is supported by the lower flange of the crushing tank, and is rotated at a high speed by a motor. The fixed disk is a disk made of stainless steel placed opposite to the rotating disk and has a diameter of about 200 mm (however,
As shown in FIG. 2 and FIG. 3, there are six protrusions for supporting the spring from the lower flange of the crushing tank), and a 30 mm diameter opening (sludge inlet) for sucking sludge is provided at the center of the disk. The crushing tank is supported by three support rods from the upper flange, and the gap between the disks can be adjusted by adjusting screws at the tips of the support rods. Crushing tank, inner diameter 300mm, height 300mm
The cylindrical part and the upper flange are made of acrylic, and the lower flange is made of stainless steel.

Next, an experimental method will be described.

The sample used in the experiment was surplus sludge collected from the Tobu Purification Center in Ube City, Yamaguchi Prefecture, which was concentrated (dewatered) as necessary. In the experiment, sample sludge (9.0 L) was put into the experimental device and batch operation was performed. During that time, sampling was performed at set time intervals, and the suspended solids concentration (MLSS), volatile suspended solids concentration (MLVSS), total organic carbon The measurement was performed by measuring the amount (TOC), the amount of soluble organic carbon (DOC), and the particle size distribution.

In this experiment, as shown in Table 1, the sludge concentration,
The purpose of this study was to determine the optimum conditions for solubilization of sludge by changing the combination of treatment time, disk gap, and rotation speed over a wide range. Since it is difficult to compare the solubilization ratios with each other, a value obtained by dividing the amount of soluble organic carbon by the total amount of organic carbon was used as an index for uniformly comparing the solubilization ratio. The solubilization ratio referred to below means this.

[0040]

[Table 1] Next, the results of experiments performed using the above-described experimental apparatus and experimental method will be described.

First, regarding the progress of sludge crushing,
A description will be given based on a change in the median diameter (central diameter) over time.

FIG. 4 is a diagram showing an example of a change in the median diameter with the lapse of time. Although the disk gap and the sample concentration, which are the experimental parameters, were changed over a wide range, almost the same was observed in all cases. Shows a tendency, initial (after 1 minute)
The decrease in the median diameter is remarkable, and thereafter, it gradually decreases, indicating that the median diameter has decreased to about 20 μm.

The reason why the median diameter sharply decreased during the initial period was that large protozoa and aggregated microorganisms in the sludge were effectively crushed or dispersed in a very short time. Thereafter, the reason for the gradual decrease and the median diameter of about 20 μm is that the cell membrane of the microorganism is crushed, but the cell membrane itself is hardly crushed.

Next, the solubilization rate when the disk gap and the sample concentration are fixed and the number of rotations is changed will be described. FIG. 5 shows an example of this, in which the disk gap is 5 m.
m, the sample concentration was 22000 mg / L, and the rotation speed was 3500 rpm (37 m / s in peripheral speed), 4000 rpm (42 m / s in peripheral speed), and 5000 rpm.
FIG. 4 is a diagram showing the relationship between the number of rotations and the solubilization rate when (peripheral speed is 52 m / s).

As shown in FIG. 5, the higher the number of revolutions, the higher the solubilization rate. At 5000 rpm, the solubilization rate becomes about 50% in 45 minutes, and at 4000 rpm, the solubilization rate reaches 50% in about 65 minutes. 3500r
At pm, it takes about 105 minutes to reach a solubilization rate of 50%, but in any case, a solubilization rate of about 50%, which is a standard that can be effectively used as a sludge crusher, has been achieved. That is, it was confirmed that in the experimental range of a peripheral speed of 37 m / s to a peripheral speed of 52 m / s, an effective practical solubilization ratio could be achieved mainly by sludge crushing due to the rotational shear force of a rotating disk rotating at a high speed.

The reason why the solubilization rate tends to be saturated at about 50% is that, as described above, in the present invention in which sludge is crushed mainly by the rotational shearing force of a rotating disk rotating at a high speed, the cell membrane of microorganisms is used. This is because even if the cell membrane is crushed and its internal substance is solubilized, the cell membrane itself is hardly crushed. Initially, the change in the solubilization rate was small, and the change after that was a large change due to the temperature rise caused by the batch processing (in this experiment, from 10 ° C at the start of the experiment, 30 to 40 ° C in about 30 minutes)
Temperature rise up to this point).

Although the effect of the temperature of the sludge on the solubilization is not described in the experimental conditions in Table 1, as one of a series of experimental studies, the effect of preheating (preheating) the sludge is considered. An experiment (preheating temperature: 50 ° C to 80 ° C) was performed, and according to the results, details are omitted. For example, sludge held at 70 ° C for 30 minutes is 2 to The solubilization rate of 30% is reached, and the crushing process is started after heating the sludge in advance,
Furthermore, it has been clarified that by heating and maintaining the temperature of the sludge during the crushing treatment, the cell membrane of the microorganisms constituting the sludge can be denatured and the crushing can be performed more effectively.

Next, a description will be given of the solubilization rate when the disk gap is changed while the number of rotations is kept constant and the sample concentration is kept substantially constant. FIG. 6 shows an example of such a case, in which the number of revolutions is 5000 rpm (peripheral speed 52 m / s) and the sample concentration is about 19,000 mg / L.
FIG. 4 is a diagram showing the relationship between the disk gap and the solubilization rate when the disk gap is 5 mm, 10 mm, and 20 mm.

As shown in FIG. 6, the disk gap is 5 mm to 20 m.
In the range of m, there is almost no difference in the solubilization rate due to the difference in the disk gap. That is, it was confirmed that the solubilization progressed to the same extent even if the disk gap was increased, unlike the idea of the prior art in which sludge solubilization was promoted by making the disk gap as small as possible.

Although the detailed description is omitted, the disk gaps of 0.1 mm and 0.2 mm, which are the experimental parameters shown in Table 1, are used.
Similar results were obtained in experiments performed on mm, 0.4 mm, 1 mm, 2 mm, and 3 mm.

Next, the solubilization rate when the number of rotations and the disk gap are fixed and the sample concentration is changed will be described. FIG. 7 shows an example of this, in which the number of rotations is 5000 rpm.
(Peripheral speed 52m / s), the disc gap is 10mm, and the sample concentration is
It is a figure which showed the relationship between a sample concentration and a solubilization rate when it changed into 3230 mg / L, 9540 mg / L, and 18200 mg / L.

As shown in FIG. 7, if the rotation speed and the disk gap are the same, the higher the sample concentration, the higher the solubilization rate. This is because, as the sample concentration increases, a rotation speed gradient that generates a rotational shear force capable of crushing sludge tends to be formed farther from the surface of the rotating disk.
The concentration of surplus sludge settled normally is 6000-7000mg
/ L, and at this level, it is reasonable to perform the crushing treatment without performing costly or labor-intensive concentration.

From the detailed and extensive first embodiment described above, it is clear that in the present invention in which sludge is crushed mainly by the rotational shear force of a rotating disk rotating at a high speed, the disk gap hardly affects the solubilization rate. Therefore, as a second embodiment, an experimental result will be described in which the fixed disk is removed from the above-described experimental apparatus and only the rotating disk is used.

FIG. 8 shows an example of the result. The rotation speed was set to 5000 rpm (peripheral speed: 52 m / s). For comparison, a fixed disk was used and the disk gap was 10 mm. It is a figure shown as a relation of a rate. The sample concentration was about 7000 m for the case with only the rotating disc.
g / L, about 15000 mg / L for the case with fixed disk.

As shown in FIG. 8, the solubilization rate at each elapsed time when the fixed disk is not used is reduced to about 75% on average, as compared with the case using the fixed disk. Considering that the higher the sample concentration is, the higher the solubilization rate is, as described in FIG. 7, it can be said that approximately 80% of the solubilization rate can be achieved. Accordingly, it was confirmed that the treatment time required to reach the predetermined solubilization rate was slightly longer, but was sufficiently practical.

As described above, according to the above-described embodiment, the rotating disk which rotates at a high speed and the driving means for driving the rotating disk are provided. It is possible to provide a very simple device of crushing sludge mainly by the rotational shear force of the rotating disk, comprising a fixed disk having In addition to this simple configuration, since precision machining of the rotating disk is not required, it is possible to provide a low-cost sludge crushing apparatus that is easy to maintain and manage.

Further, since the disk gap can be set large, even sludge containing sand or the like can be effectively treated without damaging the apparatus, and
The maintenance of the device is easier and lower cost. Although the embodiments of the present invention have been described above, it is apparent that various changes may be made in the form and details without departing from the spirit and scope of the present invention defined in the appended claims. . For example, in the above embodiment, the diameter of the rotating disk is set to 200 mm, but this is for the experimental apparatus used in the above embodiment, and does not limit the present invention at all. The diameter of such a rotating disk is
It is to be determined according to the amount of sludge to be treated and its properties, etc. Further, a suitable disk gap or rotation speed corresponding to this is not limited to the above-described embodiment, and is to be appropriately determined. Condition.

In the above embodiment, a batch type sludge crusher was described. However, for example, a sludge supply port and a discharge port are further provided in the sludge crusher as in the above embodiment so that the sludge treatment flow rate can be reduced. By constructing a crushing tank having a residence time necessary to obtain a predetermined solubilization rate, it can be used as a continuous sludge crushing apparatus.

Further, in the above embodiment, the motor is provided below the crushing tank, and the fixed disk is provided above the rotary disk. However, the motor is provided upside down, and the motor is provided above the crushing tank. It is also possible to arrange the fixed disk below the rotating disk, in which case,
The possibility of sucking air from the suction port of the fixed disk is eliminated, and the present invention can be further suitably implemented.

Further, a first motor is provided below the crushing tank, and a first rotating disk driven by the first motor is provided. Further, a second motor is provided above the crushing tank, and a second motor driven by the second motor is provided. And a rotating disk may be provided, and the disk may further be provided with a first fixed disk and a second fixed disk.

[0061]

The sludge crushing apparatus of the present invention includes a rotating disk that rotates at a high speed at a peripheral speed of about 30 m / s or more, and driving means for driving the rotating disk. In addition, a fixed disk having a sludge suction port is further provided, and a disk gap between the fixed disk and the rotating disk is set to about 5 mm or more, thereby enabling an extremely simple device of crushing sludge mainly by the rotating shear force of the rotating disk. In addition to this simple structure, precision machining of the rotating disk is not required, so that there is an effect that the maintenance and management are easy and a low-cost apparatus is provided.
The apparatus for treating organic sewage of the present invention including such a sludge crushing apparatus is an apparatus which is easy to maintain and manage and has a low cost, and has an effect capable of significantly reducing the volume of excess sludge.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an experimental apparatus used for an experimental study of the present invention.

FIG. 2 is a photograph of the experimental apparatus of FIG. 1, which is a photograph before sludge is introduced.

FIG. 3 is a photograph of the experimental apparatus of FIG. 1 after sludge is introduced.

FIG. 4 is a diagram illustrating an example of a change in median diameter with elapsed time.

FIG. 5 is a diagram showing an example of a change with time in the solubilization rate when the disk gap and the sample concentration are fixed and the number of rotations is changed.

FIG. 6 is a diagram showing an example of a change with time in the solubilization rate when the disk gap is changed while the rotation speed is kept constant and the sample concentration is kept substantially constant.

FIG. 7 is a diagram showing an example of a change with time in the solubilization rate when the sample number is changed while the rotation speed and the disk gap are constant.

FIG. 8 is an example of an experimental result in which only a rotating disk is used, and is a diagram showing a relationship between a disk gap and a solubilization ratio as compared with a case having a fixed disk.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 11/00 ZAB C02F 11/00 ZABA (72) Inventor Tomoki Kawamura 2-4-1-1, Tokiwadai, Ube City, Yamaguchi Prefecture No. Ube National College of Technology F-term (reference) 4D028 BD11 BE08 4D059 AA06 BK11 BK12 4D063 DD05 DD14 FF12 GA10 GC31 GC40 GD04 GD12 GD19 GD22 GD24 4D067 EE32

Claims (8)

[Claims] 1. A sludge crusher for crushing sludge generated by biological treatment of organic wastewater, comprising: a rotating disk rotating at a high speed; and driving means for driving the rotating disk. A sludge crushing device characterized in that sludge is crushed by a rotational shear force of the sludge. 2. The sludge crushing apparatus according to claim 1, wherein the rotating disk is a rotating disk that rotates at a high speed at a peripheral speed of about 30 m / s or more. 3. A fixed disk opposed to the rotating disk and having a sludge suction port at a center portion, wherein the fixed disk is provided with a predetermined disk gap with the rotating disk. The sludge crushing device according to claim 1 or 2. 4. The predetermined disk gap is approximately 5 mm.
The sludge crushing device according to claim 3, characterized in that: 5. The sludge crushing apparatus according to claim 3, further comprising a disk gap adjusting means for adjusting the disk gap. 6. The sludge crushing apparatus according to claim 1, wherein the rotating disk is a rotating disk having a rough disk surface. 7. The apparatus according to claim 1, further comprising heating means for heating the sludge in the sludge crushing apparatus, wherein the heating means keeps the temperature of the sludge at about 50 ° C. or higher.
The sludge crushing apparatus according to claim 6. 8. A biological treatment means for biologically treating organic wastewater, a solid-liquid separation means for solid-liquid separation of a treatment liquid treated by the biological treatment means, and the solid-liquid separation means Sludge crushing means for crushing at least a part of the separated sludge separated by the above, and organic sewage water having at least a part of the sludge crushed by the sludge crushing means returned to the biological treatment means. An apparatus for treating organic sewage, wherein said sludge crushing means is constituted by the sludge crushing apparatus according to any one of claims 1 to 7.