JP2962037B2 - Sludge refining mixing tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adding a flocculant to a slurry sludge discharged from a purification facility for sewage, night soil, industrial waste, clean water and the like, mixing the sludge and flocculating the sludge. The present invention relates to a sludge refining and mixing tank for forming a sludge.

[0002]

2. Description of the Related Art The treatment of sewage discharged from purification facilities such as sewage, human waste, industrial waste, and tap water has been conventionally performed by the following method. That is, the sewage is guided to a sedimentation basin, and in the sedimentation basin, sludge such as earth and sand in the sewage is settled and primary separated. Next, the sewage from which the sludge has been primarily separated is guided to an aeration tank, and the sewage is aerated in the aeration tank. In this way, the aerated sewage is guided to the final sedimentation basin, where the sludge remaining in the sewage is sedimented and separated. Next, the slurry sludge taken out from the final sedimentation basin is led to a temper mixing tank, in which a coagulant is added and mixed into the slurry sludge, and the slurry sludge is coagulated to form flocs. I do. Next, the flocculated sludge is dewatered and then dumped or incinerated.

FIG. 2 is a schematic vertical sectional view of a conventional tempering mixing tank. As shown in FIG. 2, the conventional temper mixing tank 1
A stirring shaft 3 having a plurality of stirring blades 2 is rotatably mounted vertically inside a cylindrical or rectangular tube type. The stirring shaft 3 is rotated about its axis by a motor 4 provided outside the tank.

A sludge supply port 5 is provided on the bottom wall 1a of the tempering mixing tank 1.
The coagulant supply port 6 is provided below the side wall 1b. Further, a discharge port 7 for floc sludge is provided in an upper portion of the side wall 1b of the temper mixing tank 1.

The slurry-like sludge A is supplied to the bottom wall of the temper mixing tank 1.
1a, the flocculant passes through the flocculant supply port 6 provided at the lower part of the side wall 1b of the temper / mixer tank 1 and enters the temper / mixer tank 1 respectively. Supplied. The slurry sludge and the flocculant supplied into the temper mixing tank 1 rise toward the upper part of the temper mixing tank 1 while being mixed and stirred by the rotating stirring blades 2, during which the slurry sludge is flocculated. Formed. The sludge thus flocculated is discharged outside the tank through a discharge port 7 attached to the upper part of the side wall 1b of the temper mixing tank 1.

[0006]

In order to efficiently agglomerate and flocculate the slurry sludge A in the temper mixing tank 1, the mixing of the slurry sludge and the flocculant in the tank should be as short as possible. Time and evenly, and
It is necessary to stir the uniformly mixed slurry sludge and coagulant at an appropriate stirring speed for a predetermined time.

However, in the conventional temper mixing tank described above, since the sludge supply port 5 and the flocculant supply port 6 are separated, the slurry sludge and the flocculant supplied from the respective supply ports are separated. The contact and mixing cannot be performed in a short time in the tank, and the supplied flocculant must wait for being dispersed in the tank by the rotating stirring blade 2. Therefore, it takes a long time to flocculate the slurry-like sludge in the temper mixing tank 1, and the generated floc has a high water content after dehydration.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and to bring a slurry sludge into contact with a flocculant in a tank in a short time and to mix the slurry sludge efficiently to form floc. It is an object of the present invention to provide a sludge refining and mixing tank capable of reducing the water content of the generated floc after dehydration.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems. As a result, the refining mixing tank is formed in a cylindrical shape with a lower part formed in a cone shape, a nozzle for coagulant injection is connected to a sludge supply pipe provided at the lower end thereof, and the inside of the sludge supply pipe is passed through the nozzle. It has been found that if the flocculant is injected into the passing slurry sludge, the slurry sludge and the flocculant can be contacted and mixed in a short time, and the slurry sludge can be efficiently flocculated and flocculated.

The present invention has been made on the basis of the above findings, and the present invention relates to a method for adding a flocculant to sludge, mixing the two, and coagulating the sludge to form flocs. Inside, a stirring shaft having a stirring blade is vertically mounted rotatably about its axis, a sludge refining mixing tank, the refining mixing tank is cylindrical, the lower part thereof The sludge supply pipe is connected to a sludge supply port at the lower end thereof, and a sludge supply pipe is connected to the lower end of the sludge supply port. A nozzle for injecting the coagulant with a narrowed diameter is detachably attached, and the coagulant injected into the slurry sludge from the nozzle mixes the slurry sludge and the coagulant. Things.

Next, the temper mixing tank of the present invention will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing one embodiment of the temper mixing tank of the present invention. As shown in FIG. 1, the tempering mixing tank 8 of the present invention has a cylindrical shape, and its lower portion 8a is formed in a cone shape whose diameter continuously decreases toward the lower end.

A stirring shaft 3 having a plurality of stirring blades 2 is rotatably and vertically mounted in the tempering mixing tank 8, and the stirring shaft 3 is driven by a motor 4 provided outside the tank. The rotation about the axis is the same as in the related art.

The lower part formed in a cone shape of the temper mixing tank 8
A sludge supply port 5 is provided at the lower end of 8a, and a sludge supply pipe 9 is connected to the sludge supply port 5. A coagulant supply port 10 is provided in a portion of the sludge supply pipe 9 adjacent to the sludge supply port 5, and the coagulant supply port 10 is provided with a coagulant injection nozzle 11 having a narrowed tip. Are detachably attached by a flange 12. At the upper part of the side wall 8b of the temper mixing tank 8, an outlet 7 for the floc sludge is provided.

[0014]

The slurry sludge A is supplied from the sludge supply port 5 into the temper mixing tank 8 through the sludge supply pipe 9. Then, a flocculant is injected into the slurry sludge passing through the sludge supply pipe 9 from the nozzle 11 whose tip is narrowed. As a result, the flocculant is injected into the slurry sludge from the nozzle 11 at a high speed, so that the injected flocculant collides with the slurry sludge in the sludge supply pipe 9 to generate turbulent flow.

Accordingly, the slurry sludge and the flocculant come into contact with each other in a short period of time, and are supplied in a mixed state from the sludge supply port 5 into the temper mixing tank 8. Mixed. Since the lower part 8a of the refining mixing tank 8 is formed in a cone shape, the rising speed of the slurry sludge and the flocculant supplied therein is fast, and the dead zone is eliminated, and the mixing of both is accelerated. You. Therefore,
The slurry sludge and the flocculant can be sufficiently mixed in a short time, whereby the slurry sludge can be efficiently flocculated and flocculated.

The injection nozzle 11 is connected to the coagulant supply port 10.
Even if the injected sludge flows backward and adheres to the nozzle 11 to block it, the nozzle 11 can be easily removed and cleaned.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a cylindrical refining mixing tank 8 having a diameter of 1 m and a height of 1.8 m and having a cone-shaped lower part is used. The coagulant was injected into the sewage mixed sludge from the nozzle 11, and the slurry sludge and the coagulant in the temper mixing tank 8 were mixed by the rotating stirring blade 2. The coagulant injection rate was 0.6%. The formed floc was discharged from the discharge port 7 of the temper mixing tank 8 and dewatered. As a result, the water content was 75%.

For comparison, a diameter of 1 m shown in FIG.
Using a conventional cylindrical tempering mixing tank 1 with a height of 1,8 m,
The same slurry-like sewage-mixed sludge as above is supplied through a supply port 5 provided in the bottom wall 1a, and
The coagulant is supplied through a supply port 6 provided in the lower part of 1b, and the slurry sludge and coagulant in the temper mixing tank 8 are
Mixing was performed by the rotating stirring blade 2. The coagulant injection rate was 0.6% as above. The generated flocks,
The water was discharged from the outlet 7 of the temper mixing tank 1 and dewatered. As a result, the water content of the floc was 78%.

As is clear from the above, when the temper mixing tank 8 of the present invention is used, the moisture content of the dewatered floc is reduced by 3% as compared with the case where the conventional temper mixing tank 1 is used. I was able to.

[0020]

As described above, according to the temper mixing tank of the present invention, the slurry sludge and the flocculant are brought into contact in a short time and mixed in the tank, whereby the slurry sludge is efficiently converted. Industrially useful effects such as flocculation and floc formation and reduction of the water content of the formed floc after dehydration can be brought about.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view showing one embodiment of a temper mixing tank of the present invention.

FIG. 2 is a schematic vertical sectional view showing an example of a conventional tempering mixing tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temper mixing tank 2 Stirrer blade 3 Stirrer shaft 4 Motor 5 Sludge supply port 6 Coagulant supply port 7 Outlet 8 Temper mixing tank 9 Sludge supply pipe 10 Coagulant supply port 11 Nozzle 12 Flange A Slurry sludge

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C02F 11/00-11/20 B01D 21/00-21/34 B05B 1/00-3/18 B05B 7/00-7 / 08 B01F 7/16

Claims (1)

(57) [Claims] 1. A stirring shaft having stirring blades therein for adding a flocculant to sludge and mixing the two, and agglomerating sludge into flocs, is rotatable about its axis. A sludge refining mixing tank, which is vertically attached to the sludge refining mixing tank, wherein the refining mixing tank has a cylindrical shape, and a lower portion thereof is formed in a cone shape having a continuously small diameter toward a lower end, A sludge supply pipe is connected to a sludge supply port at the lower end, and a nozzle for injecting a coagulant with a narrowed tip is detachably attached to a portion of the sludge supply pipe close to the supply port, A sludge refining mixing tank characterized in that the slurry sludge and the flocculant are mixed by the flocculant injected into the slurry sludge from the nozzle.