JP2000288425A - Method and device for solid-liquid separation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate fine particles from liquid to be treated mixed with the fine particles by a combination of electrostatic attraction, centrifugal force and magnetic attraction. SOLUTION: The liquid to be treated mixed with solids is imparted with negative charge, then it is fed from the upper part of the inside of a vertical cylinder and is turned and dropped, and also is applied with centrifugal force, thus the solids contained in the liquid to be treated are moved to the inner wall side of the cylinder, and also, a positive electrode is placed in the vicinity of the inner wall of the cylinder and the solids carrying negative charge are attracted. The cylinder is placed in the magnetic field and the magnetic body in the solids is attracted to the cylinder, and the solids adsorbed and attracted are dropped with their empty weights, and are taken out from the lower part of the cylinder, and the liquid from which the solids are separated is ascended in the central part of the cylinder and is discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for imparting electric charge to a solid (hereinafter referred to as "fine particles") mixed in a liquid to perform electrical adsorption, centrifugal force caused by swirling a liquid to be treated, and magnetic adhesion caused by a magnetic field. And a solid-liquid separation method and apparatus for continuously separating fine particles in the liquid to be treated.

[0002]

2. Description of the Related Art Conventionally, an online centrifuge in a magnetic field has been known (Japanese Patent Application Laid-Open No. 61-222560).
A screw decanter for separating solid and liquid by high-speed rotation is also known (JP-A-4-40878).

[0003]

In the conventional online centrifuge, the rotor can be rotated by magnetic force in a sealed path to perform necessary separation. Used for rotation.

A screw decanter configured to separate solid and liquid by high-speed rotation is used as a solid-liquid separator for various liquids for separating fine particles in a liquid. When the difference between the particles is small, when the particles are ultra-fine particles such as 10 μm or less, or when the viscosity of the liquid is equal to or greater than the centrifugal force applied to the particles, the separation of the particles becomes insufficient or difficult. was there.

Further, the fine particles adhering to the inner wall of the rotary cylinder are collected and discharged to one side by a screw, but there is a problem that abrasion powder of the screw may be caught in the liquid.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to an integrated system in which a negative charge is applied to a positive electrode to be adsorbed, the centrifugal force is used to attach the negative electrode to an inner wall of a cylinder, and a magnetic field is applied to magnetically attach magnetic particles. The above problem was solved by separating the solid and liquid in an appropriate manner.

In other words, the invention of the method is to apply a negative charge to a liquid to be treated mixed with a solid substance, and then supply the liquid from the upper portion of a vertical cylinder to swirl and lower the liquid, and apply a centrifugal force to the liquid to be treated. The solid contained therein is moved to the inner wall side of the cylinder, and a positive electrode is placed near the inner wall of the cylinder to adsorb the negatively charged solid, and the cylinder is placed in a magnetic field. The magnetic substance in the solid is magnetically attached, the solid adsorbed and magnetized is lowered by its own weight, taken out from the lower part of the cylinder, and the liquid from which the solid is separated rises in the center of the cylinder. And then discharging the solid-liquid. The liquid to be treated mixed with solids is supplied obliquely downward from the tangential direction in the upper part of the cylinder.To impart a centrifugal force to the liquid, a stirring rod is rotated in the liquid to be treated, or It rotates a cylinder.

The invention of another method is a solid-liquid separation method characterized in that the above-mentioned separation method is repeated a plurality of times while changing the conditions of adsorption and magnetic adhesion of solids.

Next, the invention of the apparatus is characterized in that a cylinder is vertically installed on a machine frame, and a liquid supply pipe having a negative charge applying means is connected obliquely downward from a tangential direction to an upper part of the cylinder, and a central portion of the cylinder is provided. The drainage tube is inserted into, and the lower end is opened at the lower part in the cylinder, a positive electrode is provided close to the cylindrical wall, and the base end of the drainage pipe is connected to the upper part of the drainage tube, A discharge means is provided at a lower part of the cylinder, a rotation means for applying a centrifugal force to the liquid to be processed is provided inside the cylinder, and a coil for generating a magnetic field is mounted outside the cylinder. This is a solid-liquid separation device, wherein the negative charge applying means inserts an electrode into a liquid supply pipe and applies a negative voltage to the electrode. In still another invention of the present invention, the rotating means is such that a stirring rod is fixed to a rotating shaft inserted into the drainage cylinder, and the discharging means is a rotary valve.

In the above invention, in order to separate the fine particles mixed in the liquid for each property, the present invention is connected to a plurality of tandems, and the voltage and other conditions are changed in each step, and the separation conditions are changed. Separate by using matched currents and voltages. That is, since the quality of the adsorbed material and the quality of the magnetically attached material are different, it is reasonable to treat it accordingly. For example, Pb, zinc, silver, nickel, lithium and the like can be separately separated and collected.

According to the present invention, solid-liquid is separated by comprehensive processing such as applying electric charge, applying centrifugal force, and magnetically attaching the fine particles, and the fine particles adhere to the inner wall (or electrode) of the cylinder. However, the liquid to be treated flows in a swirling flow, and when the adhesion layer of the fine particles becomes thick, the adhesion force (adsorption force, magnetic adhesion force, etc.) and other external forces (liquid flow, gravity) inevitably occur. The balance of the particles is lost, and the gravitational force acting on the fine particles eventually becomes larger and falls by its own weight, and accumulates in the lower part of the cylinder. Therefore, only the fine particles are discharged using a rotary valve or the like.

If the viscosity of the liquid to be treated is high, heating or dilution or other means is used to facilitate the movement of the fine particles. In the case of treating a powder, an appropriate amount of water is added (for example, 80% to 90%) to impart fluidity and dispersibility to obtain the liquid to be treated. The processing efficiency according to the present invention is:
The accuracy is determined by the capacity of the equipment, and the accuracy is determined by the processing conditions.In general, high accuracy, high voltage, high magnetic field, and a long separation cylinder are essential requirements.
It is necessary to rationally deal with the required separation accuracy.

In the above, there are a method in which various fine particles are separated at a time and then the separated fine particles are individually classified, a method in which individual particles are separated according to the present invention, and a case in which the above methods are mixed. For example, it is easier to mix and separate substances having similar charge characteristics, magnetic strength, specific gravity, etc., and then individualize them.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a method in which a charge is imparted to a liquid to be treated mixed with fine particles, and the separation efficiency is low or the separation is poor by centrifugation, charge separation and magnetization separation. This is a separation method that improves practicality and imparts practicality.

According to the present invention, in order to carry out the above-mentioned method, means for imparting a negative charge before feeding the liquid to be treated is provided so that the liquid to be treated can be swung into a vertical cylinder for centrifugation. In addition, a rotating means for inserting the cylinder into the magnetic field, assisting the turning of the liquid to be treated, and applying a centrifugal force is provided therein. In addition, a liquid discharging means is provided in the cylinder and a discharging means for separated fine particles is provided to enable continuous processing.

[0016]

Embodiment 1 An embodiment of the present invention will be described with reference to FIGS. A pretreatment such as heating or moisture adjustment is performed on the liquid to be treated mixed with fine particles, and then the liquid is fed by a pump at a constant rate. In the course of this feeding, a charge is applied to the fine particles.

Next, the liquid to be treated is swirled into a separation cylinder. The cylinder is erected upright and receives a liquid to be treated from above, like a cyclone, and separates solid and liquid while rotating the liquid to be treated downward. During this time, the negatively charged fine particles are adsorbed to the positive electrode, and the magnetic fine particles are magnetically attached to the inner wall of the cylinder by a magnetic field, and all the particles adhere to the inner wall of the cylinder under centrifugal force.

That is, each fine particle moves according to a larger force due to adsorption force, magnetic adhesion force and centrifugal force.
Attraction force and magnetic adhesion force work in combination.

As described above, the adsorption force, the centrifugal force and the magnetic adhesion force act comprehensively, and even fine particles or relatively large particles that cannot be separated by themselves can be separated easily and quickly.

The adhesion force (adsorption force, centrifugal force, and magnetic adhesion force) in the above-described case inevitably causes an imbalance with its own weight when an adhesion layer of fine particles is formed. Falls with the adhesion, and continuous separation is performed smoothly and rationally.

Since no mechanical force acts on the movement of the fine particles in the cylinder, there is no risk that new fine particles will be generated due to abrasion (for example, using a screw). Therefore, continuous separation with high efficiency can be performed for a long time.

[0022]

Embodiment 2 An embodiment of the apparatus according to the present invention will be described with reference to FIGS. A cylinder 2 for separation is vertically erected on a machine frame 1, and a tip of a liquid supply pipe 3 is tangentially formed on one upper side of the cylinder 2.
In addition, the connection opening is formed to be inclined downward, and the electrode 4 for applying a negative charge is provided inside the liquid supply pipe 3. At the center of the cylinder 2, a drain cylinder 5 is inserted and installed through the top plate 2 a, and the lower end of the drain cylinder 5 is opened at the lower part of the cylinder 2. The rotary shaft 6 is inserted into the drainage cylinder 5, the upper end of the rotary shaft 6 is connected to the drive shaft 8 of the motor 7, and the lower end of the rotary shaft 6 is connected to the base of a stirring rod 10 via an arm 9. Fix the end and stir the rod 1
0 is installed upright in parallel with the rotating shaft 6. The lower part of the cylinder 2 is a discharge tube 11 formed in an inverted conical shape, a discharge tube 12 is connected to the discharge tube 11, and a rotary valve 13 is interposed in the discharge tube 12. A drain pipe 14 is connected to the upper end of the drain cylinder 5, a coil 15 for generating a magnetic field is mounted outside the cylinder 2, and a positive electrode 16 is installed inside the cylinder 2. is there. In the figure, reference numeral 17 denotes an electrostatic generator, and reference numeral 18 denotes a power supply for the coil.

In the above embodiment, when the liquid to be treated (for example, crude oil) is heated to about 500 ° C. and supplied into the liquid supply pipe 3 as shown by arrow 19, the liquid to be treated is negatively charged by the negative electrode 4. Is given tangentially and downward from the upper side wall of the cylinder 2 as shown by the arrow 20, so that it descends while spirally turning inside the cylinder 2. On the other hand, when the blade motor 7 is started, the rotating shaft 6 is rotated via the driving shaft 8 and the stirring rod 10 is rotated via the arm rod 9 at the lower end of the rotating shaft 6, so that a centrifugal force is applied to the liquid to be treated. I do. The number of rotations of the rotating shaft 6 varies depending on the properties of the liquid to be treated and the length of the arm rod 9 for fixing the stirring rod 10, but is usually 2000 to 4000 rpm.
The rotation direction in this case is the direction indicated by the arrow 21 in FIG. 3 (the direction in which the supplied liquid to be processed is swirled), and promotes the swirling force. The fine particles having negative charges in the liquid to be processed which swirls down as described above are adsorbed to the positive electrode as shown by arrow 22, and the fine particles having magnetism magnetically adhere to the inner wall of the cylinder as shown by arrow 23. The non-magnetic fine particles are pressed against the inner wall of the cylinder by centrifugal force.

In the above description, when the adsorbed, magnetically adhered, or pressed fine particles fall below the weight of the positive electrode or the inner wall of the cylinder (or the magnetically adhering force), the fine particles 25 fall by their own weight as indicated by arrow 24. Then, it accumulates in the discharge cylinder 11. The fine particles accumulated in the discharge cylinder 11 are
When 3 is rotated in the direction of arrow 26, it is discharged as indicated by arrow 27 for a predetermined amount, and is sent to the next step. Further, the drainage liquid from which the fine particles have been separated is discharged into the drainage cylinder 5 as shown by arrows 28 and 29.
Then, it rises inside, is discharged from the drain pipe 14 as shown by the arrow 30, and is sent to the next step (drain processing apparatus).

When power is transmitted to the coil 15 described above, magnetic particles in the fine particles magnetically adhere to the inner wall of the cylinder 2. In this case, the substance to be magnetized can be controlled by regulating the amount of current flowing through the coil.

The strength of the magnetic field generated by the coil 15 is, for example, 500 A × 1000 T, so that the strength of the magnetic field can be adjusted by changing the current. Alternatively, the electrostatic voltage is, for example, 50,000 V. By changing the electrostatic voltage, fine particles to be attracted or magnetized can be selected. Therefore, if the apparatus of the above embodiment is connected in tandem so that different fine particles can be separated according to the purpose of separation, the necessity of re-fractionating the separated particles can be reduced.

[0027]

According to the present invention, the liquid to be treated mixed with fine particles is subjected to electrostatic adsorption, magnetic adhesion and centrifugal force to perform a comprehensive separation process. There are various effects such as separation with high efficiency and separation from a highly viscous liquid being relatively easy.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the method of the present invention.

FIG. 2 is a cross-sectional view in which a part of the embodiment of the apparatus is omitted.

FIG. 3 is a plan view partially omitted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Machine frame 2 Cylinder 3 Supply pipe 4 Negative electrode 5 Drain cylinder 6 Rotating shaft 7 Motor 8 Drive shaft 9 Arm rod 10 Stir bar 11 Drain cylinder 12 Drain pipe 13 Rotary valve 14 Drain pipe 15 Coil 16 Positive electrode 17 Static electricity Generator 18 Power supply for coil 25 Particles

Claims (8)

[Claims] After a negative charge is applied to a liquid to be treated mixed with a solid material, the liquid is supplied from the upper portion of a vertical cylinder and swirled down, and is centrifugally applied to be contained in the liquid to be treated. The solid material is moved to the inner wall side of the cylinder, and a positive electrode is placed near the inner wall of the cylinder to adsorb the negatively charged solid material. The magnetic substance is magnetized, the solid matter adsorbed and magnetized is lowered by its own weight, taken out from the lower part of the cylinder, and the liquid from which the solid matter is separated is discharged by raising the central part of the cylinder. A solid-liquid separation method characterized in that: 2. The solid-liquid separation method according to claim 1, wherein the liquid to be treated mixed with a solid is supplied obliquely downward from a tangential direction at an upper portion of the cylinder. 3. The solid-liquid separation method according to claim 1, wherein a centrifugal force is applied to the liquid by rotating a stirring rod or a cylinder in the liquid to be treated. 4. A solid-liquid separation method, wherein the separation method according to claim 1 is repeated a plurality of times while changing the conditions of solid substance adsorption and magnetic adhesion. 5. A cylinder is vertically installed on a machine frame, a liquid supply pipe having a negative charge applying means is connected obliquely downward from a tangential direction to an upper part of the cylinder, and a drainage cylinder is provided at a central part of the cylinder. Insert and open the lower end at the lower part in the cylinder, provide a positive electrode close to the cylindrical wall, connect the base end of the drainage pipe to the upper part of the drainage cylinder, the lower part of the cylinder A solid-liquid separation apparatus, comprising: a discharge means; a rotation means for applying a centrifugal force to the liquid to be processed fed into the cylinder; and a coil for generating a magnetic field mounted outside the cylinder. 6. The solid-liquid separation device according to claim 5, wherein the negative charge applying means inserts an electrode into the liquid supply pipe and applies a negative voltage to the electrode. 7. The solid-liquid separation device according to claim 5, wherein the rotating means has a stirring rod fixed to a rotating shaft inserted into the drainage cylinder. 8. The solid-liquid separation device according to claim 5, wherein the discharge means is a rotary valve.