JP2009160506A - Crushing apparatus and sludge treatment system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crushing apparatus which attains an increase in the crushing capacity with simple and inexpensive structure. <P>SOLUTION: The crushing apparatus 13 for crushing the crushing object in fluid is provided with a hollow disk-like crushing vessel 20 formed with an annular flow path therein and opened at the lower face, and a pair of nozzles 30, 30 jetting fluid roughly along a tangential line of the annular flow path on the annular flow path, and disposed so that the jetted fluid collides countercurrently to each other. A rubber nozzle is adopted as the nozzle 30. The sludge treatment system 10 is provided with a solubilization tank 12 solubilizing activated sludge, the crushing apparatus 13 for crushing cell walls of the solubilized activated sludge, a neutralization tank 14 neutralizing the activated sludge, and a settling tank 17 settling and separating the sludge. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for crushing a granular crushing object contained in a fluid. This technique is preferably used to reduce the volume of activated sludge by crushing the cell walls of microorganisms contained in activated sludge generated when organic wastewater (sewage) is purified by the activated sludge method.

Conventionally, an activated sludge method is known as a highly efficient method for purifying sewage.
In the purification treatment based on the activated sludge method, sludge is purified by introducing sludge (microorganisms) having an ability to purify wastewater into the treatment tank together with the wastewater and aeration. In this purification treatment, the activated sludge eats the pollutant components and newly generates activated sludge. Therefore, it is necessary to remove a part of the increasing activated sludge as excess sludge. Therefore, the activated sludge in the treatment tank is collected by sedimentation, a part of it is used again for purification as return sludge, and the rest is concentrated, dewatered and disposed as surplus sludge.

In order to reduce the volume of the excess sludge, it is necessary to crush the strong cell walls of microorganisms contained in the activated sludge. Therefore, a technique for reducing the volume of sludge by physically crushing the cell wall of activated sludge without depending on chemicals has been proposed in consideration of the environment.
As a method for physically crushing the cell wall of activated sludge, a method of applying a shear force by discharging from a nozzle, a method of applying a frictional force with a mill, a method of applying an impact by stirring with a stirring blade, glass beads, etc. There are known a method of stirring and impacting together with a colliding object, a method of causing impact by causing jets to collide with each other, and the like.

  For example, Patent Document 1 proposes a wastewater treatment method that employs a method of stirring activated sludge to give an impact to a cell wall. This wastewater treatment method involves collecting and recovering activated sludge associated with treated water obtained by aeration and purification of activated sludge and wastewater in a treatment tank, and stirring the activated sludge or applying ultrasonic waves to the activated sludge. After being homogenized by the physical means, it is returned to the treatment tank.

  Further, Patent Document 2 proposes a sludge volume reduction system that employs a method in which jets of activated sludge collide with each other and impact the cell walls. This sludge volume reduction system is provided with an opposing collision device for decomposing microbial flocs forming activated sludge and further crushing the microorganisms and floc-forming components. The opposed collision device is a device that settles and separates activated sludge in treated water that has been purified in a treatment tank, pumps up the surplus of the activated sludge that has been settled, branches it into two systems, and makes the activated sludge collide oppositely as a high-speed fluid. is there.

Further, Patent Document 3 discloses a sludge pulverization method that employs a method in which activated sludge is discharged from a nozzle to give a shearing force. This sludge pulverization method applies pressure to the activated sludge and discharges it at high speed from a narrow gap in order to improve the biodegradability by crushing the microorganisms and organic matter particles constituting the activated sludge, and passes through the gap. It is crushed by the shearing force generated when
JP 2000-24698 A JP 2004-50067 A JP 2002-219376 A

  In view of the above prior art, the present invention has an object to propose a crushing apparatus that realizes an improvement in crushing capability with a simple and inexpensive structure in a technology for physically crushing a granular crushing object contained in a fluid. To do. In addition, the present invention proposes a crushing apparatus that realizes an improvement in crushing capacity with a simple and inexpensive structure in a technology for physically crushing and refining microorganisms and organic particles (cell walls) contained in activated sludge. The problem is to further reduce the volume of activated sludge.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, according to the first aspect of the present invention, there is provided a crushing device for crushing an object to be crushed in a fluid, a hollow disk-shaped container having an annular channel formed therein and an open bottom surface, and the annular flow on the annular channel. It includes a pair of nozzles arranged so that the fluid is ejected substantially along the tangent line of the path, and the ejected fluid collides oppositely on the annular flow path.

  According to a second aspect of the present invention, there is provided a crushing device for crushing an object to be crushed in a fluid, an annular channel having an arc-shaped cross section that swells toward an outer peripheral side, and a tangential line of the annular channel on the annular channel. And a pair of nozzles arranged so that the ejected fluid collides and opposes on the annular flow path.

  According to a third aspect of the present invention, the pair of nozzles are Laval nozzles.

  According to a fourth aspect of the present invention, one of the pair of nozzles ejects fluid from one end of the annular channel in the width direction toward the center in the width direction of the annular channel, and the other nozzle is the annular channel The fluid is ejected from the other end in the width direction toward the center in the width direction of the annular channel.

  6. The sludge treatment system for reducing the volume of activated sludge according to claim 5, wherein a solubilization tank for solubilizing activated sludge by adding an alkaline agent and a cell wall degrading enzyme as a solubilizer to the activated sludge. And a crushing device according to any one of claims 1 to 4 for crushing a cell wall of the solubilized activated sludge, and adding a neutralizing agent to the activated sludge in which the cell wall is crushed. And a neutralization tank for neutralizing the activated sludge and a sedimentation tank for settling and separating sludge from the neutralized activated sludge.

  As effects of the present invention, the following effects can be obtained.

According to the present invention, the fluid ejected into the annular channel efficiently collides with each other, so that the improvement of the crushing ability of the crushing device can be expected. Furthermore, this crushing device has a simple and inexpensive structure.
Further, in the sludge treatment system provided with the crushing apparatus according to the present invention, the cell walls of microorganisms contained in the activated sludge are solubilized and crushed by the opposing collision of the activated sludge jet, so that the above-mentioned is more effective. The cell wall can be crushed to contribute to the volume reduction of activated sludge.

Next, embodiments of the invention will be described.
FIG. 1 is a diagram showing a configuration of a sludge treatment system according to an embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a crushing device according to an embodiment of the present invention, and FIG. 3 is a sectional view of a Laval nozzle.

[Sludge treatment system 10]
First, the outline | summary of the sludge processing system 10 which comprises the crushing apparatus 13 is demonstrated.
The sludge treatment system 10 is for reducing the activated sludge generated in the wastewater purification system based on the activated sludge method. In the wastewater purification system based on the activated sludge method, the activated sludge is put into the septic tank together with the sewage and aerated to purify the contaminated components in the sewage with the activated sludge. The activated sludge (returned sludge, surplus sludge) that has been settled and separated after the purification treatment is a treatment target of the sludge treatment system 10.

  As shown in FIG. 1, the sludge treatment system 10 includes a pretreatment tank 11, a solubilization tank 12, a crushing device 13, a neutralization tank 14, a precipitation tank 17, a solubilizer supply device 15, and the like.

  The pretreatment tank 11 is a treatment tank for charging activated sludge containing a large amount of water, allowing it to settle, and further condensing the activated sludge. In the pretreatment tank 11, the condensed activated sludge (hereinafter referred to as “water to be treated”) is drawn out and transferred from the pretreatment tank 11 to the solubilization tank 12.

  The solubilizer supply device 15 is a device for supplying and mixing a predetermined amount of the solubilizer 44 to the water to be treated transferred from the pretreatment tank 11 to the solubilization tank 12. Here, “solubilization” means that the cell wall of activated sludge is softened to be easily crushed.

In this embodiment, an alkaline agent (for example, sodium hydroxide) and a cell wall degrading enzyme (for example, cellulase, hemicellulase, mecellulase, maceroteam, accelerator) are used as the solubilizer.
The alkaline agent functions as a solubilizing aid, and an alkaline and highly active cell wall degrading enzyme is added to the water to be treated which has been made alkaline by adding the alkaline agent, so that the activity in the water to be treated is increased. It is intended to solubilize the sludge cell walls.
Further, by making the water to be treated alkaline with a solubilizing agent, the cytoplasm components of the cell wall of the activated sludge are eluted, and the activated sludge becomes a BOD source that can be used when purifying the sewage.
In addition, by adding alkaline and highly active cell wall degrading enzyme to alkaline treated water, the cytoplasm components in the cell wall swell and cracks are formed in the cell wall, so that the activated sludge cell wall in the treated water is efficiently removed. Can be solubilized.

The solubilization tank 12 is a treatment tank for solubilizing activated sludge to which an alkaline agent and a cell wall degrading enzyme are added as a solubilizing agent.
The solubilization tank 12 is provided with a bubble supply pipe 41 for supplying bubbles to the water to be treated from the bottom of the tank, a stirring blade 42 for stirring the water to be treated, and its driving means 43, and a solubilizing agent is added. The water to be treated is aerated and stirred.

  The crushing device 13 is a device for physically crushing the cell wall of activated sludge in the water to be treated. The configuration of the crushing device 13 will be described in detail later.

The neutralization tank 14 is a treatment tank for introducing the neutralizing agent 45 into the alkaline water to be treated in which the cell wall of the activated sludge has been crushed by the crushing apparatus 13 to neutralize it. The neutralization tank 14 is provided with a bubble supply pipe 46, a stirring blade 48, and a driving means 47 for stirring the water to be treated.
The water to be treated neutralized in the neutralization tank 14 is transferred to the precipitation tank 17. The settling tank 17 is a treatment tank for settling and separating activated sludge contained in the water to be treated. The supernatant liquid of the sedimentation tank 17 is drained, and the sediment is returned to the purification tank of the wastewater purification system as activated sludge (return sludge).

In the sludge treatment system 10 having the above configuration, the activated sludge is treated in the following flows (1) to (6).
(1) The activated sludge extracted from the septic tank of the wastewater purification system is put into the pretreatment tank 11, and this activated sludge is allowed to settle and condense.
(2) The water to be treated in the pretreatment tank 11 is transferred to the solubilization tank 12. At the stage before transfer to the solubilization tank 12, the solubilizer is added to the water to be treated by the solubilizer supply device 15. In addition, you may add a solubilizer to the to-be-processed water transferred to the solubilization tank 12. FIG.
(3) In the solubilization tank 12, the water to be treated to which the solubilizing agent is added is aerated and stirred.
(4) The treated water is transferred from the solubilization tank 12 to the crushing device 13, and the cell wall of the activated sludge in the treated water is crushed by the crushing device 13.
(5) The water to be treated is transferred from the crushing device 13 to the neutralization tank 14 and neutralized by introducing a neutralizer into the water to be treated.
(6) The neutralized water to be treated is transferred to the sedimentation tank 17, and the activated sludge in the water to be treated is settled and separated. The water to be treated in the settling tank 17 is separated into a supernatant liquid and a precipitate, the supernatant liquid is discharged, and the precipitate is transferred to a purification tank of a waste water purification system.

[Crushing device 13]
Next, the crushing device 13 will be described.
The crushing device 13 according to the present invention is for crushing an object to be crushed in a fluid, and performs a crushing action caused by a pressure difference between the inside and outside of the nozzle and a crushing action caused by collision of a jet flow from the nozzle in the fluid. Can be given to objects to be crushed.
In a present Example, the fluid processed with the crushing apparatus 13 is the activated sludge used as the said to-be-processed water, and a crushing object is a cell wall of activated sludge.

  As shown in FIG. 2, the crushing device 13 includes a crushing container 20, a recovery container 21, a pumping container 23, a pumping pump 24, a pressurizing pump 26, a flow rate adjusting pipe 27, and a nozzle 30. Is done. A circulation flow path 22 is provided between the recovery container 21 and the pumping container 23, and a pressure supply flow path 25 including a pressurizing pump 26 and a pumping pump 24 is provided between the pumping container 23 and the flow rate adjusting pipe 27. Is piped.

  The crushing container 20 is a hollow disk (disk) -shaped container having an open bottom surface, in which an annular channel is formed. That is, the crushing container 20 has an outer shape in which a substantially circular upper surface 51 and a side surface 52 having a substantially semicircular cross section that swells to the outer peripheral side are smoothly and integrally connected so that corners are not formed. An opening 53 is provided. An annular flow path having an arc-shaped cross section that swells to the outer peripheral side is formed by the side wall of the crushing container 20.

The crushing container 20 ejects fluid (water to be treated) substantially along the tangent line of the annular channel on the annular channel, and the ejected fluid collides and collides with the annular channel. A pair of arranged nozzles 30 and 30 are provided. The nozzle 30 is provided through the side surface 52 along the tangential direction of the side surface 52 of the crushing container 20.
In addition, the nozzle with which the crushing container 20 is provided is not limited to a pair, and can also have two pairs, three pairs, and a plurality of pairs of nozzles.

  Further, of the pair of nozzles 30, 30, one nozzle 30 ejects fluid from one side end of the annular channel in the width direction (vertical direction in FIG. 2) toward the center of the annular channel in the width direction. The other nozzle 30 is provided with a slight inclination with respect to the tangential direction so as to eject the fluid from the other end portion in the width direction of the annular channel toward the center in the width direction of the annular channel. Thereby, the fluid ejected from the nozzles 30 and 30 collides at the substantially center in the width direction of the annular flow path.

  The fluid ejected from the nozzles 30 and 30 flows through an annular flow path formed in the crushing container 20. As described above, the jet flows through the annular channel of the crushing container 20 to generate cavitation, and the crushing object is crushed because forces such as shear, tension, and compression act on the crushing object in the fluid. be able to.

Further, the fluid is ejected in the tangential direction from obliquely downward to upward from the nozzles 30 and 30 or in the tangential direction from obliquely upward to downward on the annular flow path, so that the fluid does not escape to the annular flow. It will effectively collide with each other on the road. Further, the fluid scattered by the opposing collision collides with the cell wall and the inner side wall of the crushing container 20.
That is, in the crushing container 20, collision between the crushing objects in the fluid and collision between the crushing object and the side inner wall of the crushing container 20 occur. Accordingly, the object to be crushed in the fluid is more effectively crushed.
Then, the fluid after the object to be crushed is naturally dropped from the opening 53 on the lower surface of the crushing container 20 and discharged from the crushing container 20.

A Laval nozzle is adopted as the nozzle 30.
The Laval nozzle is a “tapered wide nozzle” that includes both a tapered nozzle and a wide nozzle. As shown in FIG. 3, the Laval nozzle (nozzle 30) has a straw portion 35 with a substantially constant nozzle diameter, a reduced diameter portion 36 in which the nozzle diameter of the straw portion 35 gradually decreases, and a nozzle diameter toward the discharge port 39. And a throat portion 37 provided between the diameter-reduced portion 36 and the diameter-expanded portion 38.

  The Laval nozzle is provided with a downstream portion in which the enlarged diameter portion 38, the throat portion 37, the reduced diameter portion 36, and a part of the straw portion 35 are formed, and the remaining portion of the straw portion 35 is formed for the convenience of processing. The upstream portion is configured separately. As a result, the reduced diameter portion 36 and the throat portion 37 that are subject to pressure wear can be partially replaced.

  The fluid passing through the Laval nozzle is maintained or increased in pressure when it is pumped up to the throat portion 37, and is released to normal pressure at once by the enlarged diameter portion 38, and is ejected vigorously from the discharge port 39. Therefore, the fluid ejected from the nozzles 30 and 30 moves along the annular flow path on the inner wall of the side surface of the crushing container 20 and can vigorously collide with each other.

  In addition, a shearing force is generated in the fluid ejected from the Laval nozzle due to a pressure difference when passing through the nozzle. Accordingly, the object to be crushed in the fluid ejected from the nozzle 30 is crushed by the shearing force.

The collection container 21 is a container for collecting a fluid that naturally falls from the opening 53 on the lower surface of the crushing container 20 after the object to be crushed is crushed in the crushing container 20.
The crushing container 20 is disposed in the collection container 21.

  In the recovery container 21, both the circulation channel 22 and the drain channel 63 are provided so as to be switched by valve bodies 61 and 62. The circulation channel 22 is a channel for transferring a fluid to the pumping container 23 via a transfer pipe. The drainage channel 63 is a channel for draining the fluid recovered in the recovery container 21 and transferring it to the neutralization tank 14.

  The pumping container 23 is a container for storing a fluid containing a crushing object. The fluid stored in the pumping container 23 is pumped up to the pressurizing pump 26 through the pumping flow path 25 by the pumping pump 24, and further pumped to the flow rate adjusting pipe 27 by the pressurizing pump 26. That is, the pumping pump 24 and the pressurizing pump 26 function as a fluid pressure feeding means.

  The flow rate adjusting pipe 27 is provided with a flow rate adjusting valve 65, a branch pipe 66, and a pressure sensor 28. By adjusting the degree of opening and closing of the flow rate adjusting valve 65, the flow rate of the fluid flowing to the nozzle 30 is adjusted, and the pressure of the fluid ejected from the nozzles 30 and 30 is adjusted. A branch pipe 66 is connected downstream of the flow rate adjusting valve 65. On the downstream side of the branch pipe 66, a pipe joint 67 for connecting the two nozzles 30 and 30 and a pressure sensor 28 for measuring the pressure of the fluid pumped to the nozzles 30 and 30 are connected. A pressure measuring valve 68 is inserted between the branch pipe 66 and the pressure sensor 28.

In the crushing device 13 having the above-described configuration, the crushing processing of the crushing object in the fluid is performed in the following flows (1) to (5).
(1) The fluid containing the object to be crushed is introduced into the pumping container 23. In this embodiment, the water to be treated (fluid) including the cell wall (crushed object) of activated sludge is transferred from the solubilization tank 12 to the pumping container 23.
(2) The pumping pump 24 is operated with the pressure measuring valve 68 closed, and the fluid in the pumping container 23 is pumped up to the flow rate adjusting pipe 27. After the pressure measuring valve 68 is opened and the pumping pump 24 confirms that the fluid is pumped up by the pressure sensor 28, the fluid is ejected from the nozzles 30 and 30 when the pressurizing pump 26 is operated.
(3) The flow rate adjustment valve 65 of the flow rate adjustment pipe 27 is operated and adjusted so that the pressure of the fluid ejected from the nozzles 30 and 30 becomes a predetermined pressure.
(4) The fluid ejected from the nozzles 30 and 30 collide oppositely, and the object to be crushed is crushed by this impact. Further, the object to be crushed is also crushed when the fluid collides with the inner wall of the crushing container 20. If the pressure of the fluid ejected from the nozzle 30 is set to 5.0 MPa, the fluid ejects from the nozzles 30 and 30 and collides oppositely at a speed of about 460 km / h.
(5) The fluid after the object to be crushed in the fluid is crushed by the collision falls from the lower surface opening of the crushing container 20 to the collection container 21 and is collected in the collection container 21. In the recovery container 21, the valve bodies 61 and 62 are set in advance so that the circulation flow path 22 becomes effective, and the recovered fluid is returned to the pumping container 23 again and processed in the flow (1) to (4) above. Is done. And if the crushing object in a fluid is crushed moderately, the valve bodies 61 and 62 will be switched so that the drainage flow path 63 of the collection container 21 may become effective, and the fluid will be drained from the crushing device 13. In this embodiment, the water to be treated whose activated sludge cell walls have been crushed by the crushing device 13 is transferred to the neutralization tank 14.

The crushing device 13 is not only used for crushing the cell wall of activated sludge, but can be widely used for crushing granular crushing objects contained in fluid.
For example, a gas containing pollen that is an object to be crushed can be ejected from the nozzles 30 and 30 of the crushing device 13 to crush the cell wall (outer shell) of the pollen.
Further, for example, a liquid containing colloidal particles that are objects to be crushed can be ejected from the nozzles 30 and 30 of the crushing device 13 to crush and refine the colloidal particles.

The crushing device 13 according to the present invention ejects a fluid substantially along a tangent line of the annular flow channel on the annular flow channel, and a crushing container 20 having a hollow disk shape in which an annular flow channel is formed and having an open lower surface. A pair of nozzles 30 and 30 are arranged so that the ejected fluid collides oppositely on the annular flow path.
In other words, the crushing device 13 ejected the fluid while ejecting the fluid substantially along the tangent line of the annular channel on the annular channel and the annular channel having an arc-shaped cross section that swells to the outer peripheral side. It is configured to include a pair of nozzles 30 and 30 arranged so that the fluid collides oppositely on the annular flow path.
In the crushing device 13 configured as described above, the fluid ejected into the annular flow path efficiently collides oppositely, so that an improvement in crushing capability can be expected. Furthermore, since this crushing device 13 does not require a special drive device or the like, it has a simple and inexpensive structure.

  Furthermore, it is desirable that the pair of nozzles 30 and 30 provided in the crushing device 13 is a Laval nozzle. By adopting the Laval nozzle, the object to be crushed in the fluid can be effectively crushed by the pressure difference of the fluid that is ejected through the nozzle.

  Further, of the pair of nozzles 30, 30 provided in the crushing device 13, one of the nozzles 30 ejects a fluid from one end portion in the width direction of the annular channel toward the center in the width direction of the annular channel, The other nozzle 30 preferably ejects fluid from the other end portion in the width direction of the annular channel toward the center in the width direction of the annular channel. By disposing the nozzles 30 and 30 in this way, the fluid ejected from the nozzle 30 moves along the inner wall of the crushing container 20 in the swiveling direction and the direction substantially orthogonal to the swirling direction. Then, the fluid ejected from the nozzles 30 and 30 is collected at the approximate center in the width direction of the annular channel in the crushing container 20 and can collide efficiently.

And the sludge treatment system which concerns on this invention adds the alkaline agent and a cell wall decomposing enzyme as a solubilizer to activated sludge, the solubilization tank for solubilizing activated sludge, and the solubilized activated sludge A crushing device for crushing the cell wall, a neutralizing tank for neutralizing the activated sludge by adding a neutralizing agent to the activated sludge having the cell wall crushed, and sludge from the neutralized activated sludge And a sedimentation tank for sedimentation and separation.
According to the sludge treatment system 10 having the above-described configuration, the cell walls of microorganisms contained in the activated sludge are solubilized and crushed by the opposing collision of the activated sludge jet, so that the cell walls can be crushed more effectively. Therefore, it can contribute to volume reduction of activated sludge.

The figure which shows the structure of the sludge processing system which concerns on the Example of this invention. The figure which shows the structure of the crushing apparatus which concerns on the Example of this invention. Sectional drawing of a Laval nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sludge processing system 11 Pretreatment tank 12 Solubilization tank 13 Crushing apparatus 14 Neutralization tank 15 Solubilizer supply apparatus 17 Precipitation tank 20 Crushing container 30 Nozzle

Claims (5)

A crushing device for crushing a crushing object in a fluid,
A hollow disk-shaped container having an annular channel formed therein, and an open bottom surface;
A pair of nozzles arranged so that the fluid is ejected substantially along the tangent line of the annular channel on the annular channel, and the jetted fluid collides oppositely on the annular channel,
A crushing device comprising the crushing device. A crushing device for crushing a crushing object in a fluid,
An annular flow path having an arc-shaped cross-section that bulges to the outer periphery side;
A pair of nozzles arranged so that the fluid is ejected substantially along the tangent line of the annular channel on the annular channel, and the jetted fluid collides oppositely on the annular channel,
A crushing device comprising the crushing device. The pair of nozzles is a Laval nozzle,
The crushing apparatus according to claim 1 or claim 2. Of the pair of nozzles, one of the nozzles ejects fluid from one end portion in the width direction of the annular channel toward the center in the width direction of the annular channel, and the other nozzle is the other end in the width direction of the annular channel. The fluid is ejected from the portion toward the center in the width direction of the annular flow path,
The crushing apparatus according to claim 1 or claim 2. A sludge treatment system for reducing the volume of activated sludge,
A solubilization tank for solubilizing the activated sludge by adding an alkaline agent and a cell wall degrading enzyme as a solubilizer to the activated sludge;
The crushing apparatus according to any one of claims 1 to 4, for crushing a cell wall of the solubilized activated sludge,
A neutralizing tank for neutralizing the activated sludge by adding a neutralizing agent to the activated sludge in which the cell walls are crushed;
A settling tank for settling and separating sludge from the neutralized activated sludge,
A sludge treatment system characterized by comprising.

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