JPH105506A - Device for thickening sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to settle and thicken sludge added with a flocculating agent by vertically partitioning a thickening vessel with a water permeable resistance plate of meshes, etc., supplying the stock soln. added with the flocculating agent in a lower chamber and providing the upper chamber with a take-out port for separating water. SOLUTION: The thickening vessel 1 is vertically segmented with the resistance plate 2 having water permeability of the coarse meshes, etc., to the extent of allowing the capturing of flocculated floes. The upper chamber 1a of the thickening vessel 1 is provided with an overflow pipe 3 for the separating water. The lower chamber 1b is provided with a thickened sludge withdrawing pipe 4 and is provided with a supply pipe 5 for the raw water added and intimately mixed with a solidifying agent. The thickened sludge added and intimately mixed with the flocculating agent in an intimate mixing vessel 7 flows down in the supply pipe 5 and is then made into a compacted massive state. This sludge is supplied to the thickening vessel 1. The thickening vessel 1 is filled with the thickened sludge. The floating thereof is prohibited by the resistance place 2 and only the moisture accumulates in the upper chamber 1a and is taken out of the overflow pipe 3. A filter layer is formed by the thickened sludge accumulated downward in the lower chamber 1b, by which the highly thickened sludge is formed by removing the moisture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an apparatus for concentrating sludge using a polymer flocculant. Is to be provided.

[0002]

2. Description of the Related Art Conventionally, in order to concentrate flocculated sludge by adding a flocculant such as a polymer, it is difficult to settle and concentrate the sludge. Generally, flocculated floc is floated by high-pressure air or the like. In addition, a method of floating by adding a foaming agent and air is also known. Japanese Examined Patent Publication No. 33435/1988 is an example.

[0003]

However, sewage sludge aggregated by adding a flocculant such as a polymer has a poor consolidation state, and it is difficult to concentrate to a high concentration by sedimentation and concentration. For this reason, in both the flotation concentration method and the normal pressure flotation concentration method, the floc is levitated using high-pressure air or a foaming agent, but in these methods, in addition to the flocculant, equipment such as a compressor or a foaming agent is used. Additives are required.

[0004]

SUMMARY OF THE INVENTION The present invention can solve the above-mentioned problems. In the present invention, when a flocculant is added and the flocculated sludge is extruded under a slight resistance, the floc is formed into a block. It was made by paying attention to the point of sinking.

That is, the gist of the present invention is to separate a concentrating tank provided with an overflow portion of separated water at an upper portion and an outlet for condensed sludge at a lower portion with a resistance plate having a water permeability such as a mesh, and to vertically separate the concentrated tank. The lower chamber is provided with a supply port for a stock solution to which a flocculant is added, and the upper chamber is provided with an outlet for separated water.

A pump may be used to supply the concentrate to which the coagulant has been added to the concentrating tank. However, a mixing tank for adding the coagulant is provided at a higher level than the concentrating tank, and the head difference is increased. May be supplied.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention focuses on the point of sedimentation when sludge to which a flocculant is added becomes condensed, and flocs in a stock solution sent from a flocculation mixing tank are transported. Due to the resistance in the tube, it becomes compacted, and when discharged into the concentration tank, it forms a lump and sediments in the concentration tank.

Accordingly, the floc in the stock solution supplied in this way fills the lower chamber of the concentration tank, and the pressure density is increased by the resistance of the resistance plate, thereby being highly concentrated. And
The water in the stock solution is taken out as a supernatant through a resistance plate.

That is, in the concentration tank, the condensed floc layer becomes a filtration layer, whereby water is separated, and concentrated sludge can be obtained in the lower chamber. The concentrated sludge may be taken out in a batch manner or may be taken out continuously in consideration of the degree of concentration.

As is apparent from the above description, the apparatus according to the present invention is capable of settling and separating coagulated sludge by a coagulant, which has been conventionally difficult, with a simple structure in which only a water-permeable resistance plate is provided in a concentration tank. In particular, the pressurizing energy for consolidation is sufficient due to the natural head difference and does not break the floc, so that it is possible to obtain concentrated sludge suitable for the subsequent dewatering operation. Hereinafter, the present invention will be specifically described with reference to the drawings.

[0011]

1 is a flow sheet diagram of sludge concentration provided with a concentration device according to the present invention, and FIG. 2 is an enlarged sectional view of a main part thereof. In FIG. 1, reference numeral 1 denotes a concentration tank, 2
Is a resistance plate provided so as to divide the concentration tank 2 up and down,
It is composed of a mesh having water permeability, and is composed of a coarse mesh (approximately 5 mm) large enough to capture coagulated flocs.

An overflow pipe 3 for separated water is provided in an upper chamber 1a of the concentration tank 1 which is divided into upper and lower sections, and a withdrawal pipe 4 for concentrated sludge is provided in a lower chamber 1b. In the lower chamber 1b,
A supply pipe 5 for raw water to which a coagulant is added and mixed is provided. Reference numeral 6 is a scraper for coagulated sludge.

Next, reference numeral 7 is a mixing tank for a flocculant,
In the figure, the sludge added with the flocculant is supplied to the thickening tank 1 at a position higher than the thickening tank 1 by the head difference.
Reference numeral 8 denotes a stirrer, reference numeral 9 denotes a tank of a polymer flocculant, 1
Reference numeral 0 denotes a sludge tank, reference numeral 11 denotes a sludge supply pump, and reference numeral 12 denotes a concentrated sludge extraction pump.

The concentrating apparatus according to the present invention is configured as described above, and the flocculated sludge to which the flocculant is added and mixed in the mixing tank 7 flows down the supply pipe 5 due to the head difference, and the supply pipe 5 and is supplied to the concentration tank 1 in a lump. This state is shown in FIG.

The coagulated sludge thus formed is settled in the concentration tank 1. In this way, the concentrated sludge is filled in the lower chamber 1b, but the floating is prevented by the resistance plate 2, so that only the water passes through the resistance plate and accumulates in the upper chamber 1a, and the water overflows from the overflow pipe 3 to the outside of the system. Is taken out.

That is, in the lower chamber 1b, a filtration layer is formed by the concentrated sludge accumulated below the resistance plate 2, and only the moisture is accumulated in the upper chamber 1a, and the moisture is further extracted from the coagulated sludge. And highly concentrated sludge can be obtained in the lower chamber 1b.

The concentrated sludge thus formed in the lower chamber 1b is scraped by the scraper 6, and then taken out of the system from the drawing pipe 4. The concentrated sludge may be withdrawn in a batchwise manner or in a continuous manner, depending on the condition of the separated water. In any case, in the apparatus according to the present invention, the coagulated sludge to which the coagulant has been added is further filtered using the coagulated sludge as a filter medium, so that highly concentrated sludge can be obtained.

[0018]

As described above, the present invention enables the sedimentation and concentration of sludge to which a coagulant has been added, which has been impossible to settle and concentrate in the past. It enables high concentration.
Of course, compared to conventional flotation and concentration, it does not require flotation means such as a compressor, and does not stir flocculated flocs, so that it is possible to obtain concentrated sludge suitable for subsequent dehydration treatment and the like. It is.

[Brief description of the drawings]

FIG. 1 is a flow sheet diagram of sludge concentration provided with a concentration device according to the present invention.

FIG. 2 is an enlarged vertical sectional view of the concentration device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concentration tank 2 Resistance plate 1a Upper chamber 1b Lower chamber 3 Overflow pipe 4 Extraction pipe 5 Supply pipe 7 Mixing tank

Claims (2)

[Claims] 1. An overflow section of separated water at an upper portion and a thickening tank 1 provided with an outlet 4 for concentrated sludge at a lower portion thereof are vertically divided by a resistance plate 2 having water permeability such as a mesh. A sludge concentrator comprising a chamber 1b provided with a supply port 5 for a stock solution to which a flocculant has been added, and an upper chamber 1a provided with an outlet 3 for separated water. 2. The sludge according to claim 1, wherein the mixing tank 7 for the stock solution to which the flocculant is added is provided above the thickening tank 1, and the stock solution is supplied to the thickening tank 1 with its head difference. Concentrator.