JPH07600U - Agglomeration mixing tank for preventing solid adhesion - Google Patents

Abstract

(57) [Summary] [Structure] The stirrer 24 is provided with a rotating body 24b that rotates around the axis of the rotating shaft 24a, and the upper and lower surfaces of the rotating body 24b are each formed in a cone shape. Plural blades 24c are provided on the upper side of the sludge supply pipe 28
Is provided at a position facing the lower surface of the rotating body 24b so as to face upward. [Effect] While the raw sludge 27 jetted into the coagulation stirring tank 22 flows from the central portion toward the peripheral portion along the cone shape of the rotating body 24b by the discharge pressure, the blade body 24c moves the raw sludge 27 into the rotating body 24b. The raw sludge 27 can be agitated and mixed without being entangled with the blade 24c by the fibers in the raw sludge 27 acting to push in the circumferential direction, and the tempered sludge containing the fibers can be supplied to the dehydrator. You can

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a coagulation mixing tank for preventing solids from adhering, which is used in a dehydration treatment process of sewage sludge.

[0002]

[Prior art]

 Conventionally, in the sludge dewatering process in a sewage treatment facility, a coagulant is added to the sewage sludge to improve the dewatering effect before the sewage sludge is put into a dehydrator for conditioning. As shown in FIG. 3, for example, as shown in FIG. 3, the sewage sludge is prepared by adding the sewage sludge 2 to the rapid stirring tank 1 which is a condensation process, adding the inorganic coagulant or the cationic coagulant 4, and stirring the mixture in the tank. The sewage sludge 2 and the cationic coagulant 4 are rapidly stirred and mixed by the vessel 3 to neutralize the charge of the sewage sludge 2. After that, the sewage sludge 2 in the rapid stirring tank 1 is introduced into the slow stirring tank 5 which is in the process of forming flocs, the anionic flocculant 6 is added, and the sewage sludge 2 and the anionic flocculant are added by the stirrer 7 installed in the tank. After slowly mixing 6 with stirring, the sewage sludge 2 in the slow stirring tank 5 is supplied to the dehydrator.

[0003]

[Problems to be solved by the device]

 When two-liquid conditioning of sewage sludge is performed using inorganic coagulant and polymer coagulant, cationic coagulant and anionic coagulant, etc., rapid agitation is required at the time of injecting the first liquid, that is, in the coagulation process Is. However, when the conventional agitator 3 as shown in FIG. 3 is used for rapid agitation, the fibers of the contaminants and residue contained in the sewage sludge 2 are entangled in the agitation blade 3a, which makes maintenance troublesome. There was a problem. On the other hand, when a belt press is used as a dehydrator, it is better to dehydrate the sewage sludge containing fibers without removing the fibers of contaminants and residue in the sewage sludge with a screen. .

The present invention solves the above problems, and provides a coagulation mixing tank for preventing solids from adhering, which can stir sewage sludge without entanglement of the fibers of contaminants and residue. With the goal.

[0005]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the solid substance adhesion preventing type coagulation mixing tank of the present invention comprises a coagulation stirring tank for storing raw sludge, a stirrer immersed in the coagulation stirring tank, and a driving device for rotating the stirrer. A sludge supply pipe for supplying raw sludge to the coagulation stirring tank, and a coagulant supply pipe communicating with the sludge supply pipe, and the stirrer is provided with a rotating body that rotates around the axis of the rotating shaft. The upper and lower surfaces of the rotating body are each formed in a cone shape, and multiple blades are projected on the upper and lower surfaces of the rotating body so that the opening of the sludge supply pipe faces upward to the position facing the lower surface of the rotating body. It is provided.

Further, a plurality of fixed blades are provided on the inner surface of the coagulation stirring tank.

[0007]

[Action]

 With the above configuration, the stirrer is rotationally driven by the driving device, and the raw sludge is supplied from the sludge supply pipe into the coagulation stirring tank in a state where the rotating body of the stirrer rotates around the axis of the rotating shaft. This raw sludge is obtained by adding a coagulant from the coagulant supply pipe in the middle of the sludge supply pipe, and spouts from the opening of the sludge supply pipe toward the lower surface of the rotating body of the agitator.

The raw sludge ejected into the coagulation agitation tank collides with the lower surface of the rotating body, and the discharge pressure causes the sludge to flow from the central portion to the peripheral portion along the cone shape of the rotating body and the blades provided on the rotating body. It receives the stirring action of the body and diffuses to form a stirring flow that circulates in the coagulation stirring tank. In addition, the raw sludge that becomes a downward flow and descends near the rotating shaft collides with the upper surface of the rotating body, flows from the center to the peripheral edge along the cone shape, and the stirring action by the blades provided on the rotating body. Receive and spread. By this action, the raw sludge and the flocculant are rapidly stirred and mixed.

In the above-described operation, the blade body acts to push the raw sludge flowing along the cone-shaped surface of the rotating body in the circumferential direction of the rotating body, and the raw sludge flows along the surface of the blade body. Therefore, in the past, since the raw sludge flowed in the front and back directions of the stirring blades of the stirrer, that is, along the direction of the rotation axis, the fiber in the raw sludge was entangled with the stirring blades. Since the rotating body once receives the raw sludge ejected in the axial direction of the rotating shaft, and the cone shape of the rotating body and the pushing action of the blades guide the raw sludge in the radial and circumferential directions of the rotating body. The fibers in the raw sludge do not get entangled in the blade.

Further, since the raw sludge flowing in the coagulation stirring tank in the rotating direction of the rotating body collides with a plurality of fixed blades provided on the inner surface of the coagulation stirring tank, it flows as a turbulent flow due to its stirring action. , The stirring effect is improved.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, the solid substance adhesion preventing type coagulation / mixing tank 21 has a tank body formed by a coagulation / agitation tank 22, and the inside of the coagulation / agitation tank 22 is formed by a overflow weir 23 into a main tank portion 22a. It is divided into the sub tank portion 22b. A stirrer 24 is submerged in the main tank portion 22a, and a driving device 25 for rotating the stirrer 24 is provided on a pedestal 26 that is provided around the periphery of the coagulating stirring tank 22.

The stirrer 24 includes a rotary shaft 24a connected to the driving device 25, a rotary body 24b provided at the lower end of the rotary shaft 24a, and a plurality of blade bodies 24c projecting from the upper and lower surfaces of the rotary body 24b. The upper and lower surfaces of the rotator 24b each have a cone shape, and the blade body 24c extends radially from the central portion of the rotator 24b toward the peripheral portion thereof, and is curved in an arc shape in the rotational direction. . The shape of the blade body 24c is not limited to the above-mentioned shape, and various shapes are possible.

A sludge supply pipe 28 for supplying the raw sludge 27 is arranged in the main tank portion 22a of the coagulation stirring tank 22, and the base end side of the sludge supply pipe 28 communicates with a supply source (pump or the like). The tip end side opens upward at a position facing the lower surface of the rotating body 24b. A coagulant supply pipe 30 for adding the first liquid coagulant 29 is communicated in the middle of the sludge supply pipe 28, and a sludge discharge port 31 communicating with a dehydrator is provided at the bottom of the sub tank portion 22b. It is open. Further, a plurality of fixed blades 32 are provided on the inner surface of the main tank portion 22a of the coagulating stirring tank 22.

The operation of the above configuration will be described below. The stirrer 24 is rotationally driven by the drive device 25, and the rotating body 24b and the blade body 24c are rotated around the rotating shaft center via the rotating shaft 24a, and the sludge supply pipe 28 is inserted into the main tank portion 22a of the coagulating stirring tank 22. Raw sludge 27 is supplied. A coagulant 29 is added to the raw sludge 27 from a coagulant supply pipe 30 in the middle of the sludge supply pipe 28.

The mixed fluid of the raw sludge 27 and the coagulant 27 ejected from the opening of the sludge supply pipe 28 toward the lower surface of the rotating body 24b of the stirrer 24 collides with the lower surface of the rotating body 24b, and is discharged by a pump or the like. The pressure flows along the cone shape of the rotating body 24b from the central portion toward the peripheral portion, and is diffused by receiving the stirring action of the blade body 24c provided on the rotating body 24b, and becomes a stirring flow to form the aggregation stirring tank 22. It goes around in the main tank portion 22a. Further, the raw sludge 27, which becomes a downward flow in the main tank portion 22a and descends near the rotating shaft, collides with the upper surface of the rotating body 24b and flows along the cone shape from the central portion toward the peripheral portion. , And is diffused by the stirring action of the blade body 24c provided on the rotating body 24a. By this action, the raw sludge 27 and the coagulant 29 are rapidly mixed by stirring.

In the above operation, the blade 24c acts to push the raw sludge 27 flowing along the cone-shaped surface of the rotor 24b in the circumferential direction of the rotor 24b, and the raw sludge 27 is the surface of the blade 24c. Flowing along.

Therefore, conventionally, since the raw sludge flows in the front and back directions of the stirring blades of the stirrer, that is, along the direction of the rotation axis, the fibrous material in the raw sludge is entangled with the stirring blades. In the embodiment, the raw sludge 27 ejected in the axial direction of the rotary shaft 24a is once received by the rotary body 24b, and the raw sludge 27 is pushed out by the cone shape of the rotary body 24b and the pushing action of the blade body 24c. Since the raw sludge 27 is guided in the radial direction and the circumferential direction, even if foreign matter and residue are present in the raw sludge 27, the fibrous material does not get entangled with the blade 24 c.

The raw sludge 27 flowing in the main tank portion 22 a of the coagulation stirring tank 22 in the rotation direction of the rotating body 24 b collides with a plurality of fixed blade members 22 provided on the inner side surface of the coagulation stirring tank 22, The stirring effect improves the stirring effect because it flows as a turbulent flow.

The mixture of the raw sludge 27 and the flocculant 29 rapidly stirred in the main tank portion 22 a of the coagulation stirring tank 22 flows into the sub tank portion 22 b over the overflow weir 23 and passes through the sludge discharge port 31. Is put into the dehydrator. In this charging process, the second liquid of the coagulant is charged into the sludge, and the conditioned sludge is dehydrated in the dehydrator.

Accordingly, the dewatering machine is fed with the tempered sludge containing the fibrous material of the contaminants and the residue of the raw sludge 27, so that the dewatering effect is improved.

[0021]

[Effect of device]

 As described above, according to the present invention, the raw sludge ejected into the coagulation / agitation tank flows from the central portion to the peripheral portion along the cone shape of the rotating body due to the discharge pressure, and the blade body collects the raw sludge. It acts so as to push it out in the circumferential direction of the rotating body, and since the raw sludge flows along the surface of the blade body, the raw sludge can be stirred and mixed without the fibers in the raw sludge getting entangled with the blade body, Conditioned sludge containing fibers can be supplied to the dehydrator.

Further, a plurality of fixed blades provided on the inner surface of the coagulation stirring tank can generate turbulent flow to improve the stirring effect.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view of a solid substance adhesion prevention type coagulation and mixing tank according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an overall configuration diagram showing a conventional mixing tank.

[Explanation of symbols]

 21 Solid-Attachment-Preventive Coagulation Mixing Tank 22 Coagulation Mixing Tank 22a Main Tank Section 24 Stirrer 24b Rotating Body 24c Blade Body 25 Drive Device 28 Sludge Supply Pipe 30 Coagulant Supply Pipe 32 Fixed Blade Body

Claims (2)

[Scope of utility model registration request] 1. A coagulation stirring tank for storing raw sludge, a stirrer immersed in the coagulation stirring tank, a drive device for rotating the stirrer, and a sludge supply pipe for supplying raw sludge to the coagulation stirring tank.
A coagulant supply pipe communicating in the middle of the sludge supply pipe is provided, a stirrer is provided with a rotating body that rotates around the axis of the rotating shaft, and both upper and lower surfaces of the rotating body are formed into cone shapes. A solid substance adhesion preventing coagulation / mixing tank characterized in that a plurality of blades are provided on both upper and lower surfaces, and an opening of a sludge supply pipe is provided at a position facing a lower surface of a rotating body so as to face upward. 2. The solid adhesion preventing coagulation / mixing tank according to claim 1, wherein a plurality of fixed blades are provided on the inner surface of the coagulation / agitation tank.