JPH061201Y2 - Flock blanket type coagulation sedimentation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a floc blanket type coagulating sedimentation device for solid-liquid separation of river water, lake water, wastewater, etc. by coagulating sedimentation.

<Prior art> When removing suspended solids from river water, lake water, wastewater, etc.,
It is a well-known method as a coagulation sedimentation method that a flocculant is added to raw water to flocculate suspended matter in raw water to form flocs, and the flocs are removed from water by sedimentation separation to obtain turbid water. .

There are various devices such as a slurry circulation type and a pulsating type as a device for performing the flocculation and precipitation, but the applicant of the present application first gives a swirling flow to the lower part of the flock blanket layer, and the swirling flow is given. A floc blanket type coagulating sedimentation apparatus having a floc concentrating chamber formed at the center of the floc blanket layer was proposed (Japanese Patent Application Nos. 59-250575 and 60-165954).

The outline of the floc blanket type coagulating sedimentation device is No. 6
As shown in FIG. 8 to FIG. 8, as shown in FIG. 6, a tubular body 2 having an open upper end and a closed lower end is erected at the center of the tank 1, and the tubular body 2 is closed. Is the precipitation chamber A, and the inside of the cylindrical body 2 is the floc concentrating chamber B.

Further, ring-shaped raw water pipes 4a and 4b, which communicate with the raw water pipes 3a and 3b, respectively, are attached to the lower part of the precipitation chamber A, and a nozzle-shaped raw water inlet 5a for giving a swirl flow to the upper raw water pipe 4a. In addition, the raw water inlet 4b below is provided with a raw water inlet 5b opening downward.

The operation of performing coagulation and precipitation with the apparatus is as follows.

That is, a part of the raw water added with the coagulant is swirled into the lower part of the floc blanket layer 6 from each raw water inlet 5a through the raw water pipe 3a and the raw water pipe 4a, that is, shown in FIG. As described above, the other part of the raw water, which has flown in and out in the substantially F direction on the horizontal plane between the inner wall of the tank 1 and the outer wall of the tubular body 2, and the other part of the raw water to which the coagulant has been added, is supplied to the raw water pipe 3b and the raw water pipe 4.
It flows in downward from each raw water inflow port 5b via b.

The raw water that has flowed in from each of the inflow ports 5a and 5b is agitated by jetting or a swirling flow, and the suspended substances in the raw water aggregate to form flocs, and coalesce with the floc blanket layer 6.

A state in which the flock blanket layer 6 is formed is shown in FIG. 8. Excessive flock overflows from the opening of the tubular body 2 into the inside thereof, and the suspended water from which suspended substances have been removed is transferred to the trough 7 Overflow from.

The flocs descending the tubular body 2 reach the lower part of the floc condensing chamber B, where they are stored and concentrated, and periodically discharged to the outside through the sludge drawing pipe 8.

As described above, the flock blanket type coagulating sedimentation device previously proposed by the applicant of the present invention blows out at least a part of the raw water flowing from the raw water inlet into the lower part of the flock blanket layer in a direction in which a swirling flow is generated. Therefore, it is possible to stir the flock blanket layer without having a special power part or mechanical part, to make the flock blanket concentration uniform, and to maintain and manage easily and to consume less energy.

<Problems to be solved by the invention> In the floc blanket type coagulating sedimentation device described above, a part of the raw water flowing from the raw water inlet is swirled in the lower part of the flock blanket layer. It is desirable to prevent swirling flow from occurring in the upper part of the flock blanket layer, but it is necessary to prevent the formation of a swirling flow in the upper part of the floc blanket layer. If the flock to be blown is relatively light, a swirling flow also occurs in the upper part of the flock blanket layer.

When a swirling flow occurs in the upper part of the flock blanket layer,
The linear velocity of the swirling flow is higher in the tank peripheral wall than in the center of the tank. Therefore, as shown in FIG. 8, the flocs carry over from the flock blanket layer along the tank peripheral wall, and the quality of the suspended water decreases. The disadvantage occurs.

The present invention has been made in view of the above-mentioned drawbacks. Even if the flock generated is relatively light, the swirling flow generated in the peripheral wall portion above the flock blanket layer is suppressed, and the flock blanket type agglomerate does not carry over. The purpose is to provide a precipitation device.

<Means for Solving Problems> In the present invention, a cylindrical body having an open upper end and a closed lower end is erected in the center of the tank, and a raw water inlet is provided around the lower portion of the cylindrical body. A treated water outlet is provided above the opening of the tubular body, the outside of the tubular body is a settling chamber having a flock blanket layer, and the inside of the tubular body is a floc concentrating chamber,
In a floc blanket type coagulating sedimentation device that blows at least a part of raw water in the raw water inlet in a direction in which a swirl flow is generated in a settling chamber and gives a swirl flow to a lower part of the flock blanket layer, a tank in an upper part of the flock blanket layer. A flock blanket type coagulating sedimentation device, characterized in that a plurality of baffle plates for changing the downward flow of a flock blanket swirling along the peripheral wall portion are attached to the peripheral wall of the is there.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially cutaway perspective explanatory view showing an example of an embodiment of the present invention, and FIG. 2 is a longitudinal sectional explanatory view of FIG. 1. The present invention relates to the above-mentioned conventional floc blanket type coagulating sedimentation apparatus. A plurality of baffle plates 9 are attached to the peripheral wall of the tank 1 above the flock blanket layer at intervals. The other parts are the same as those of the conventional device shown in FIG.

The baffle plate 9 used in the present invention is constructed so that the flock blanket swirling along the peripheral wall portion collides with the baffle plate 9 as shown in FIG. The angle α is attached downward to the line L.

The angle α is preferably about 30 °. Further, as shown in FIG. 4 which is a cross-sectional explanatory view taken along the line YY of FIG. 2, it is preferable that a plurality of baffle plates 9 are provided at equal intervals, usually at intervals of about 1 m. If the circumference is 8 m, 8 pieces will be attached.

<Operation> As described above, in the present invention, the flock blanket layer 6
Since a plurality of baffle plates 9 as shown in FIG. 3 are attached to the peripheral wall of the tank 1 in the upper part of the tank at equal intervals, the flock blanket layer that swirls the peripheral wall of the tank 1 collides with the baffle plate 9. Has the effect of changing the swirling flow obliquely downward,
Therefore, the swirling flow near the peripheral wall portion above the flock blanket layer can be suppressed, and the carryover of the flock in this portion can be effectively prevented.

FIG. 5 is a partially cutaway perspective view showing an example of another embodiment of the present invention. In addition to attaching the baffle plate 9, the lower end is opened from the opening of the tubular body 2. , The inner cylinder 10 with the upper end closed is inserted, one end of the communication pipe 11 is connected to the upper end of the inner cylinder 10, and the other end opening of the communication pipe 11 is communicated with the trough 7 provided above the tank 1. By arranging the opening below the water surface formed in the tank 1, a downward flow is given to the tubular body 2 due to the head difference of the water surface.

By inserting the above-mentioned inner cylinder 10 into the cylindrical body 2 in this way, a part of the clarified water overflows from the opening of the communication pipe 11 due to the water head difference, and as shown by the dotted arrow line, A downward flow of water corresponding to running water is generated in the cylindrical body 2.

Due to the downward flow, excess flocs on the upper surface in the flock blanket layer 6 are forced to flow down into the cylindrical body 2, that is, into the floc concentration chamber B, so that the sedimentation speed of the flocs in the floc concentration chamber B is increased. At the same time, the interface of the flock blanket layer 6 can be further stabilized, and the flock carryover can be more effectively prevented by acting synergistically with the above-described action of the baffle plate 9. Further, by installing the inner cylinder, it is possible to further increase the ascending streamline velocity in the tank.

The mechanism for causing a downward flow in the tubular body 2 by inserting the inner cylinder 10 into the tubular body 2 is not limited to the mechanism shown in FIG. Any shape may be used as long as an inner cylinder 10 having an open lower end is inserted into the inside of the tank 2 and a downward flow is given to the inside of the cylindrical body 2 due to a water head difference of the water surface formed in the tank 1.

<Effect> As described above, according to the present invention, in the flock blanket type coagulating sedimentation device that gives a swirling flow to the lower part of the flock blanket layer, the flock blanket swirling the peripheral wall part is placed on the peripheral wall of the tank above the flock blanket layer. Since a plurality of baffles for changing the flow direction are attached at intervals, even if the generated flock is relatively light, it occurs along the peripheral wall of the tank above the flock blanket layer. The swirling flow can be suppressed, and therefore the flocs are not carried over, so that the quality of the suspended water does not deteriorate.

In addition, by inserting the inner cylinder into the tubular body and giving an upward flow to the inner cylinder, a downward flow of a water amount corresponding to the amount of water of the upward flow can be given to the tubular body, and thereby the floc in the floc concentrating chamber The sedimentation speed of the flock blanket can be increased, the interface of the flock blanket layer 6 can be further stabilized, and the flock carryover can be more effectively prevented by acting synergistically with the baffle plate 9 described above. be able to.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, and FIG. 1 is a partially cutaway perspective view of the present invention, and FIG.
1 is a longitudinal sectional view of FIG. 1, FIG. 3 is an enlarged view of a baffle plate used in the present invention, FIG. 4 is a lateral sectional view of line YY in FIG. 2, and FIG. 5 is the present invention. FIG. 7 is a partially cutaway perspective explanatory view showing another embodiment of the present invention. Further, FIG. 6 is a partially cutaway perspective explanatory view of a conventional floc blanket type coagulating sedimentation apparatus, FIG. 7 is an explanatory view showing a direction of a part of raw water ejected from an inflow port 5a, and FIG. FIG. DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Cylindrical body 3 ... Raw water pipe 4 ... Raw water pipe 5 ... Raw water inlet 6 ... Flock blanket layer 7 ... Trough 8 ... Sludge extraction pipe 9 ... Baffle plate 10 ... Inner pipe 11 ... Communication pipe A ... Sedimentation room B ... Flock concentration room

Claims (2)

[Scope of utility model registration request] 1. A tubular body having an open upper end and a closed lower end is provided upright in the center of the tank, and a raw water inlet is provided around the lower portion of the tubular body. The treated water outlet is provided above, the outside of the cylindrical body is a settling chamber having a flock blanket layer, the inside of the cylindrical body is a floc concentration chamber, and at least a part of the raw water at the raw water inlet is swirled into the settling chamber. In a floc blanket type coagulating sedimentation device that blows out in a direction that causes a swirl flow to the lower part of the flock blanket layer, the floc blanket swirling along the peripheral wall part is lowered on the peripheral wall of the tank in the upper part of the flock blanket layer. A floc blanket type coagulating sedimentation device characterized in that a plurality of baffles for changing the flow direction are attached at intervals. 2. A downward flow is provided in the tubular body by inserting an inner tube having a lower end opened from the opening of the tubular body and draining water inside the inner tube upward due to a head difference. A floc blanket type coagulating sedimentation apparatus according to claim 1, wherein the utility model registration is as described above.