JP3387696B2 - Suspension clarification equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for clarifying a suspension, and particularly to a large amount of polluted water, river turbidity, and the like when dredging seabed sediment. The present invention relates to a clarification device for effectively performing clarification treatment of various suspensions such as turbidity of various wastewaters. 2. Description of the Related Art When a landfill is constructed by dredging the earth and sand on the seabed and using the earth and sand, a large amount of pollutant containing several hundred to several thousand mg / liter of fine clay-based suspended particles from the landfill. Water (spill water) is generated. If spilled water is discharged into the sea as it is, it will cause water pollution. Conventionally, such a turbidity treatment has been performed by a classical coagulation sedimentation apparatus. That is, a method of adding aluminum sulfate or polyaluminum chloride (PAC) as an inorganic coagulant to a suspension to be treated (hereinafter referred to as raw water), further adding a polymer coagulant, forming flocs, and performing sedimentation separation. However, this conventional method has the following problems. (1) Generally, the sedimentation / separation speed is not high, and the installation area of the apparatus is large. (2) Unless the design is made based on advanced know-how obtained by the skill of a technician, a drift occurs due to uneven distribution of raw water, density flow, and the like in the settling apparatus, and flocs tend to carry over. In sewage treatment, there is also known an apparatus that removes suspended solids from sewage by passing sewage in an upward flow through a packed bed of floating filter media, but the amount of suspended solids trapped in the packed bed reaches its limit. In this case, the supply of raw water has to be stopped to clean the filter medium, and the filter medium has to be air-cleaned by a blower. SUMMARY OF THE INVENTION The present invention solves the problems of the prior art, has a high sedimentation / separation speed, does not need to stop supply of raw water at the time of washing the filter medium, and does not require air washing. It is an object to provide a suspension clarification device that can be processed. [0005] In order to solve the above problems, according to the present invention, a suspension is circulated in an upward flow from the lower end of a packed bed filled with a buoyant hollow cylindrical filler. In the clarification device that makes the clarified water flow out from the upper part of the packed bed,
A mechanical rotating member having a horizontal single-stage or multi-stage rotary blade that horizontally rotates inside the packed bed and disturbs the packed bed is provided, and the mechanical rotating member is rotated while flowing the suspension. with a rotating means for rotating the speed 0.1～9Rpm, the hollow cylindrical filler, polypropylene
And a particle size of 10 to 25 mm. In the above, a flocculant is preferably added to the suspension of raw water. Any coagulant having a turbidity effect can be used as the coagulant. For example, various nonionic, anionic, cationic and amphoteric polymer flocculants can be used. Polymer flocculant and PAC, aluminum sulfate,
It is also possible to use an inorganic coagulant such as polyiron or ferric chloride in combination. As described above, according to the present invention, while supplying raw water in an upward flow to a packed bed filled with a floating hollow cylindrical filler, rotors are provided in a horizontal direction provided in the packed bed. When the rotating member having the vertical rotation axis is continuously or intermittently slowly rotated, the filter medium is shaken, and the suspended particles that have been trapped fall, so that the filter medium can be cleaned while performing clarification treatment of raw water. It was made after finding that it would be possible. That is, each of the hollow cylindrical fillers forms a fine sediment, but when rotated and shakes the filter medium, most of the trapped suspension falls to the bottom of the bed irrespective of the upward flow. As a result, it was recognized that it was not necessary to stop the raw water at the time of cleaning the packed bed, and that air cleaning was not required. Next, the present invention will be described in detail with reference to FIG. 1 which shows an example of the fining apparatus of the present invention in an overall configuration diagram.
In FIG. 1, 1 is a solid-liquid separation device of the present invention, 2 is a hollow cylindrical buoyant filler, and the filler is made of a lightweight plastic such as polypropylene having a specific gravity of about 0.9. It is preferable that the filter media have a particle size of 10 to 25 mm, but other media may be used. The height of the floating filling layer 3 is about 1.5 to 2 m. A net 4 is provided on the upper part of the floating filling layer 3 for preventing the floating of the filler from flowing upstream. A rotating member 5 is provided as a multi-stage rod-shaped rotating blade in the packed layer 3, and is rotated by a motor 6 in a horizontal direction at a low speed (at a rotational speed of 0.1 to 9 rpm or less).
A settling sludge scraper 8 is connected to the rotary drive shaft 7. The lower part of the filling layer is a space 9. The rotating blades of the rotating member 5 may have flat blade-like, rod-like, or other plate-like projections as long as they are provided in the horizontal direction, and the projections may be alternately or linearly formed. Any horizontal projection may be used. After the raw water 10 to which the coagulant is added is stirred in the pipe 11 for about 30 seconds to 1 minute, the raw water 10 flows into the raw water inflow section provided at the lower part of the floating filter medium packed layer 3. Agglomerated particles with good sedimentation settle in the space 9 and settle and deposit on the bottom of the apparatus. Space 9
The suspended particles that did not precipitate in
, And settles and is removed in a myriad of hollow portions of the filler in the packed bed 3 and a space formed between the fillers,
The clear treated water 12 flows out. The rectifying effect of the hollow cylindrical floating filter medium is extremely large, and turbulence and drift in the space portion 9 are almost completely suppressed from the lower end of the filler packing layer 3 to about 0.5 m, and upward flow without large turbulence. Flow
The particles that have not been settled and removed in the space 9 are effectively removed while passing through the packed bed 3, and the clarified treated water flows out of the outlet pipe 12. The settled sludge 13 is discharged by opening the drainage valve 14. The suspended particles captured by the floating filler are separated from the filler when the floating filler is shaken by the rotation of the rotating member 5, and are deposited as settled sludge on the bottom of the apparatus.
Interestingly, the suspended particles removed from the filler by the swaying of the floating filler by the rotating member have increased in particle size due to the agglomeration of the particles when trapped in the filler, improving sedimentation. It did not carry over to the treated water. Moreover, when the amount of suspended particles captured by the floating filler increases, the specific gravity of the filler increases to 1.0 or more due to the weight of the suspended particles, and the filler sinks, during which the suspended particles are removed from the filler. A phenomenon was also found in which the filler, which had peeled off and lightened again, floated. It has been recognized that the above-described operation effectively cleans the floating filler, and solves the drawbacks of the conventional technique of stopping the supply of raw water and performing air cleaning during the cleaning of the filler. Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 The sediment dredged from the sea floor off the city A flows into the landfill, and the sewage (SS120-440) flows out from the landfill.
0 mg / l) was collected at 70 m ³ / h, and 0.2 to 0.5 mg of anionic polyacrylamide polymer flocculant was collected.
/ Liter was added, and the mixture was stirred in a pipe for 30 seconds, and then allowed to flow into the bottom of a coagulation / separation apparatus having the following specifications. Apparatus diameter 2.3 m square sectional area 5.29 m ² Upflow velocity 13.2 m / h Floating filler material Hollow made of polypropylene Cylindrical filling material Floating particle size ・ ・ ・ ・ ・ ・ ・ 25mm outside diameter, 22mm inside diameter, 25mm length Filling height of floating filling material ・ ・ ・ ・ ・ ・ ・ 2.0m Height from bottom of filling layer to bottom of equipment ・ ・ ・ ・ ・1.5m Height of the space below the packed bed ・ ・ ・ ・ ・ ・ ・ 1m from the equipment bottom Height of the raw water inflow pipe ・ ・ ・ ・ ・ ・ ・ 0.6m above the equipment bottom and 0.4m below the bottom of the packed bed Rod rotation Member installation position ························································································································· /// Frequency ··························································································· 処理On 20
mg / liter or less, and there was no need to stop the raw water supply and clean the filler with air. According to the present invention, the following effects can be obtained. (1) Since the filler can be washed while removing suspended particles of the raw water, it is not necessary to stop the supply of the raw water at the time of washing the filler, and continuous processing is possible. (2) No air blower is required to clean the filler, so no blower is required. (3) The solid-liquid separation speed can be made higher than that of the coagulation sedimentation method, and the quality of treated water is good.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram showing an example of a fining device of the present invention. [Explanation of Signs] 1: Solid-liquid separation device, 2: Floating packing material, 3: Floating packing layer, 4: Spill-prevention net, 5: Rotating member, 6: Motor,
7: rotary drive shaft, 8: sludge scraper, 9: space, 1
0: Raw water, 11: Inflow pipe, 12: Outflow pipe, 13: Settled sludge, 14: Sludge valve

Continuation of front page    (72) Inventor Kenji Shima               11-1 Haneda Asahicho, Ota-ku, Tokyo Stock Association               Inside the company EBARA CORPORATION (72) Inventor Katsuyuki Kataoka               4-2-1 Motofujisawa, Fujisawa City, Kanagawa Prefecture               EBARA Research Institute, Inc.

Claims (1)

(57) [Claims 1] The suspension is allowed to flow in an upward flow from the lower end of a packed bed filled with a buoyant hollow cylindrical filler, and clarified treated water is supplied from the upper part of the packed bed. In the clarifying device for flowing out, a mechanical rotating member having a horizontal single-stage or multi-stage rotary blade that horizontally rotates inside the packed bed and disturbs the packed bed is provided, and the mechanical rotating member is suspended. It has a rotating means for rotating the rotating speed to 0.1 to 9 rpm while flowing the turbid liquid, and the hollow cylindrical filler is made of polypropylene and has a particle size of 10 to 25 mm. Clarifier.