JPH0957147A - Method and apparatus for flocculating fine substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flocculate a fine substance in water without adding a flocculant. SOLUTION: Columnar magnetic elements 3 are arranged in the cylindrical member 1 provided on the way of piping permitting water containing a fine substance to flow and water is allowed to flow through the annular passages 4 formed between the magnetic elements 3 and the inner wall surface 1a of the cylindrical member 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flocculation method and a flocculation device for fine particles contained in water such as waste water, ground water, river water, lake water, sea water, and in-tank water.

[0002]

2. Description of the Related Art Wastewater, groundwater, river water, lake water, seawater,
In the case of removing fine particles contained in water such as water in a tank, for example, suspended matter, conventionally, filtration is performed by a precoat filtration or a ceramic filter or a hollow fiber membrane filter having a submicron opening, or A flocculant was added to increase the particle size of the suspended substance for sedimentation separation or floating separation.

[0003]

However, according to the above-mentioned filtration method, for example, in the case of precoat filtration,
Since the precoat material is discarded each time, there is a problem that the amount of waste increases. Further, in the case of the hollow fiber membrane filter, since the permeation flow velocity cannot be increased, there is a problem that the device needs to be large in size in order to ensure a predetermined permeation flow rate, and therefore the equipment becomes expensive. . Furthermore, when adding a coagulant,
The problem is that a coagulant addition device and a device for performing sedimentation or flotation are required, so that the entire equipment is also expensive, and the coagulant is discharged as suspended matter, resulting in increased waste. There was also.

Therefore, it is an object of the present invention to provide an aggregating method and apparatus capable of aggregating fine particles without adding an aggregating agent or the like.

[0005]

In order to solve the above-mentioned problems, the method of aggregating a fine particle substance of the present invention is a method of causing a magnetic force to act on water containing the fine particle substance to agglomerate the fine particle substance.

In the above coagulation method, the flow velocity of water is within the range of 1 to 3 m / s, and the magnetic force (magnetic flux density) of the magnet body is within the range of 1000 to 10000 gauss.
Further, it is a method of adding an electrolytic substance or a liquid containing an electrolytic substance to water.

Further, the apparatus for aggregating fine particles of the present invention is one in which a cylindrical magnet body is arranged inside a cylindrical body which is interposed in the middle of a flow path for flowing water containing the fine particles. Further, in the above-mentioned aggregating apparatus, the flow velocity of water flowing in the tubular body is set within the range of 1 to 3 m / s, and the magnetic force (magnetic flux density) of the magnet body is set within the range of 1000 to 10000 gauss. It is a thing.

According to each of the above constructions, the magnetic force is applied to the water containing the fine particle substance to cause the fine particle substance to aggregate, so that the aggregation can be performed without adding the aggregating agent.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method and apparatus for aggregating a fine particle substance according to an embodiment of the present invention will be described with reference to the drawings.

First, an apparatus for aggregating fine particles will be described with reference to FIG. This flocculating device is used for fine particles contained in water such as wastewater, groundwater, river water, lake water, seawater, and tank water.
For example, a cylindrical body (for example, constituted by a PVC pipe) 1 interposed in the middle of a piping path (flow path) through which water containing a suspended substance flows, and is inserted into the cylindrical body 1. At the same time, it is composed of a bar-shaped magnet body 3 whose both ends are fixed by a plurality of plate-shaped brackets 2.

The magnet body 3 has an outer diameter such that it has a predetermined gap, that is, an annular passage 4 with respect to the inner wall surface 1a of the tubular body 1, and is slightly shorter than the tubular body 1. The rod-shaped magnet body 3 is formed by arranging a plurality of columnar small magnets 5 in series, and streamlined guide portions 6 for reducing flow resistance are provided at both ends thereof. . The small magnets 5 are arranged so that the S poles and the N poles face each other, and a permanent magnet is used as the small magnets 5.

Further, the magnetic force (magnetic flux density) of the magnet is within the range of 1000 to 10000 gauss, and under this magnetic force, the flow velocity of the passing water is about 1
Within the range of 3 m / s.

Next, a method for agglomerating the fine particles will be described. Water containing suspended material is fed to the flocculation device. Then, this water flows through the annular empty passage 4 in the tubular body 1 at a predetermined speed (for example, a speed of about 1.5 m / s). This time,
The magnetic force of the magnet body 3 arranged in the tubular body 1 acts on water to agglomerate the suspended substance contained in the water, for example, a size of several microns to several tens of microns. .

If necessary, sodium chloride or a liquid containing such an electrolytic substance is added as an electrolytic substance to water containing the fine particle substance. As described above, the aggregation is performed by applying the magnetic force. The Lorentz force acts on the charged particles dissolved in water, and the magnetohydrodynamic effect is generated.
This is probably because aggregation is promoted.

When water contains colloidal particles, the surface of the colloidal particles is charged "negatively" in water, and a stable dispersion state is maintained by mutual repulsion. , When water is passed through a magnetic field, an electric field is generated due to ion polarization, and an attractive force between particles (van der Worth attractive force) works due to a neutralizing effect of particle surface charge, which facilitates mutual approach of particles, After all, aggregation occurs.

Thus, the suspended substance (or
Colloidal particles) are removed by a usual filtration device.

[0017]

The experimental results of the agglomeration method described above will be described below with reference to FIG. First, the device used in the experiment will be described.

In FIG. 2, reference numeral 11 denotes a storage tank for storing water. One end of a transfer pipe 12 for transferring water containing suspended substances is connected to the lower portion of the storage tank 11, and the transfer pipe 12 is also connected. The other end is open (or connected) to the upper part of the storage tank 11.

A water circulating pump 13 and an aggregating device 14 having a magnet body according to the present invention are provided in the middle of the transfer pipe 12 in this order from the downstream side. Then, after pouring clean water having an electric conductivity of about 500 μS (Siemens) / cm into the storage tank 11, kaolin (manufactured by Tsuchiya Kaolin: ASP-170: average particle size of 0.
4 μm) was added and dispersed. At this time, the suspension concentration was about 300 PPM.

In this state, the circulation pump 13 is driven,
Water containing suspended solids was fed to the agglomerator 14 via the transfer line 12 at a flow rate of 2500 l / h and the water leaving the agglomerator 14 was analyzed.

At this time, the magnetic force of the magnet body in the aggregating device (magnetic processing unit) 14, that is, the magnetic flux density is 0 gauss (in a state where the magnet body is not arranged), 1400 gauss, 2400 gauss, and 7000 gauss. The electrical conductivity of water was 500 μs / cm, and the result of examining the aggregation state when the electrical conductivity was approximately 3600 μS / cm by adding approximately 2000 PPM of sodium chloride (an example of an electrolytic substance) is shown in the table below. 1].

[0022]

[Table 1]

From the above-mentioned [Table 1], it is clear that the aggregates are formed when the magnetic force is applied, that is, when the magnetic treatment is performed. Further, it can be seen that the degree of aggregation is larger as the magnetic force is stronger and the electric conductivity of water is larger.

FIG. 3 is a graph showing the state of particle size distribution when kaolin is added to tap water. The experimental conditions at this time are as follows.

Flow rate: 2.4 m ³ / hr, flow rate: 1.6 m / s Suspension concentration: about 300 mg / liter Electrical conductivity: about 500 μS / cm

[0026]

As described above, according to the method of aggregating a fine particle substance and the configuration of the aggregating apparatus of the present invention, the magnetic force is applied to the water containing the fine particle substance to agglomerate the fine particle substance. Compared to the case where a coagulant is used, it does not generate waste like materials, and does not require addition of a coagulant and its treatment equipment, and therefore, a treatment equipment containing fine particles can be easily and inexpensively. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fine particle substance aggregating apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing experimental equipment for an aggregation method according to the same embodiment.

FIG. 3 is a graph showing the results of an experimental example of the aggregation method in the same embodiment.

[Explanation of reference numerals] 1 cylindrical body 1a inner wall surface 3 magnet body 4 annular passage 5 small magnet

Claims (8)

[Claims] 1. A method of aggregating a fine particle substance, which comprises causing a magnetic force to act on water containing the fine particle substance to agglomerate the fine particle substance. 2. The method for aggregating a fine particle substance according to claim 1, wherein the flow velocity of the water containing the fine particle substance at the time of applying the magnetic force is set in the range of 1 to 3 m / s. 3. The method for aggregating a fine particle substance according to claim 1 or 2, wherein the magnetic force is within a range of 1000 to 10000 gauss. 4. The method for aggregating a fine particle substance according to claim 1, wherein an electrolytic substance or a liquid containing the electrolytic substance is added to water. 5. An apparatus for aggregating a fine particle substance, wherein a cylindrical magnet body is arranged inside a tubular body interposed in the middle of a flow path for flowing water containing the fine particle substance. 6. The aggregating apparatus for fine particle substances according to claim 5, wherein the magnet body is constituted by a permanent magnet. 7. A flow velocity of water flowing through an annular passage formed between the inner wall surface of the cylindrical body and the magnet body is set to be within a range of 1 to 3 m / s. 6. A device for aggregating fine particles according to item 6. 8. The magnetic force of the magnet body is set within the range of 1000 to 10000 gauss.
An aggregating apparatus for the fine-particle substances described.