KR100333894B1 - The pneumatic tribo charging and separator - Google Patents

Abstract

The present invention relates to a method and apparatus for separating fine powder using triboelectric vestibular separation.

When low pressure blower air (air pressure 1000-5000mmAq) and fine powder are put into the air inlet and fine powder inlet, the fine powder naturally introduced by expansion of low pressure blower air (air pressure 1000-5000mmAq) is transferred to the fine powder mixing part and charged powder In the tube and the charged powder diffusion unit, the fine powder is charged in the third phase by collision with the particles and the particles, and the particle and the wall, respectively, and flows into the vertical electrostatic separator in the aerosol state. Due to the shape of the charged powder induction wing and the outlet of the charged powder injection port, the charged powder which is uniformly flowed in the width direction of the electrode plate and moved in the positive or negative electrode direction according to the polarity of the charge is separated into a central separator plate, respectively. Teflon or epoxy on the top and bottom of the electrode plate to make the flow of powder uniform and adhere to the electrode plate to prevent weakening the electric field strength. Combining the insulating plate of quality, the thrust plate connected to the rotating rod rotating 1 to 5 circuits per minute, the thrust plate at the top of the electrode plate to remove the charged powder attached to the electrode plate, and also increases the parallel plate type electrode plate It is possible to simply increase the processing capacity by increasing the width in the horizontal direction, increasing the size of the fine powder mixing nozzle and the fine powder mixing part, increasing the horizontal width of the charged powder diffusion part, and increasing the number of parallel pieces of the charged powder diffusion part.

Description

Powder separation method and apparatus using airflow collision tribostatic electrostatic separation method {The pneumatic tribo charging and separator}

The present invention relates to a powder separation method and apparatus using the airflow impact triboelectric charge electrostatic separation method. More particularly, the present invention relates to a method and apparatus for separating an active ingredient from fine powders in which two or more different substance components are mixed, and unrefined in coal ash, which is a waste generated from benefication of various minerals, especially coal-fired power plants. The present invention relates to a method for charging and separating fine powder using an electrostatic property of an object that can be used to separate unburned carbon and ash or to remove ash from coal, and an apparatus used therein.

The electrostatic separation method is used to separate the fine powder mixture and charge the material by using the unique electrical properties of each material, such as dielectric constant, electrical conductivity and work function. As a separation method, there are a charging by conductive induction, a charging by ion or electron bombardment, and a charging by contact or friction method.

Among these, the contact or triboelectrification method is the most useful method for the electrostatic separation of non-conductive fine powder mixtures. All materials have a unique work function according to the surface chemical composition. When two materials with different functions come into contact, they exchange electrons until there is no difference in the work function at the contact interface, so that materials with low work functions have positive charges and those with high materials have negative charges. It is separated by using. Therefore, the contact or friction charging method includes a method of contacting and rubbing two materials to be separated and charging each other, and a method of contacting or rubbing a third material, that is, a material having a median value of two work functions, to charge.

Patent application No. 97-68549 discloses that finely introduced fine powder by expansion of compressed air is first charged by collision with particles and particles, particles and nozzle walls by strong turbulence in a venturi injector. In the aerosol state, it is tangentially introduced into the rotating frictional charging body and the secondary friction is generated by collision with the rotating frictional charging wall or collision between the particles due to the high speed rotational vortex, which is uniformly applied to the vertical electric field separator. The fine powder moved in the direction of (+) electrode or (-) electrode according to the charged charge polarity is separated into rotatable yield control plate (part connected to center separator is fixed by shaft) and center separator respectively. The method and apparatus are described. In this method, the fine powder charge rate was low, and the charged powder adhering to the electrode plate could not be easily removed, and thus there was a difficulty in discharging between the electrode plate and the central separator or maintaining the flow of intake air and charged powder uniformly. In addition, since the powder processing capacity per electrode plate width is limited, in order to increase the fine powder processing capacity, a plurality of electrode plates are installed in parallel and the electrode plate width is expanded to increase the powder processing capacity. Compressed air consumption increases in proportion to the capacity, which leads to high initial installation and operating costs, and the raw material input device is attached to the rotating frictional charged body. As the number of brushes and air cylinders for removing fine powder is also increased, the device is complicated and difficult to maintain. Moreover, the rotational speed of the rotating frictional electret rotating blades is high speed (2000 rpm to 4000 rpm). When increasing, the length of the rotary blade is extended in the width direction, so that the mechanical vibration and the rotating part There is a problem such as wear, such as operation, maintenance is difficult and power ratio increases.

The present invention is to solve the above problems, to increase the rate of charge as an efficient fine powder charging device, to reduce the cost by adopting a fine powder mixing nozzle using low pressure air, and a fine powder mixing unit suitable for increasing the capacity and It is an object of the present invention to easily increase the powder processing capacity by using an electrostatic separator and a parallel plate type electrode plate capable of using a charged powder diffusion part and a chuck hammer.

In order to solve the object of the present invention, the low-pressure blower air (air pressure 1000 to 5000 mmAq) is introduced through the air inlet, and the fine powder introduced through the fine powder inlet is mixed with the fine powder, the charged powder conveying tube, and the charged powder. The charging efficiency is improved by tertiary charging by contact friction with the particles or the wall surface over the three sections of the negative, and the charged powder is formed in the electrode plate width direction by the shape of the charged powder induction blade and the outlet of the charged powder injection port inside the charged powder diffusion part. By uniformly flowing into the electrostatic separator, the insulating plate is coupled to the top and bottom of the electrode plate, and the central separator is installed between the electrode plate to prevent discharge and equalize the flow of intake air and charged powder, Remove the charged powder attached to the electrode plate and place it in one powder mixing nozzle and one powder mixing unit with increased processing capacity. It is a feature of the present invention to easily increase the processing capacity by connecting the charged powder diffusion parts as many as the number of unit cells, and by expanding the width of the electrode plate and installing them in parallel.

1 is a schematic view of a fine powder separating apparatus according to the present invention

2 is a schematic view of an apparatus for removing charged powder attached to an electrode plate of the present invention.

3 is a schematic diagram of the present invention in which the device is increased with increasing capacity.

4 is a cross-sectional view of the fine powder mixing nozzle and the fine powder mixing portion of the present invention

5 is a cross-sectional view of the charged powder diffusion portion of the present invention

6 is a schematic view of a conventional powder separating apparatus

7 is a cross-sectional view of a conventional fine powder mixing portion

8 is a schematic diagram of the prior art in which the apparatus is increased with increasing capacity.

9 is a graph showing the results of an embodiment in which coal ash is added to the apparatus of the present invention and separated.

<Description of the symbols for the main parts of the drawings>

1. Air inlet 2. Fine powder mixing part

3. Fine powder inlet 4. Fine powder mixing nozzle

5. Charged powder conveying pipe 6. Raw material hopper

7A, 7B. Drive motor 8. Charged powder inlet

9. Charged powder induction wing 10. Charged powder diffusion part

11. Charged powder injection hole 12. Electrostatic separator

13. Yield Control Plate 14. Center Separator

15A, 15B. Insulation plates 16A, 16B, 16C. Electrode plate

17. Electrostatic Separator Enclosure 18. Chutapan

19. Chutahammer 20A, 20B. Spinning rod

21.Spring 22A, 22B Cyclone

23A, 23B. Fine powder collector 24A, 24B. Air outlet

25A, 25B. Bag Filter (B / F) 26. Rotary Friction Charger

27. Electrostatic Separator 28. Cyclone and Powder Collector

29. Raw material input section

In order to electrostatically separate the fine powder by frictional charging, when a low pressure blower air (air pressure 1000 to 5000 mmAq) is introduced into the air inlet 1, the fine powder is discharged to the fine powder inlet 3 together with external air by expansion of the blower air. After being sucked up, it is accelerated by the fine powder mixing nozzle 4 and the low pressure blower air and fine powder in the fine powder mixing part 2 are entangled by strong stirring, and the fine powder and the fine powder and fine powder mixing parts having different surface energy (2) The fine powder is charged with (+) (-) by friction and collision with the wall. Due to the rapid discharge rate of air, the charged powder is once again charged by contact frictional charging with the charged powder conveying tube 5 wall when passing through the charged powder conveying tube 5 without aggregation. The charged powder conveyed to the inlet of the charged powder diffusion unit 10 is charged once again while passing through the charged powder inducing blade 9 and uniformly diffused in the width direction, and then the charged powder injection hole 11 having an outlet width of 4 to 8 mm. ) Is uniformly injected into the vertical electrostatic separator 12 in an erosol state. The powder charged with (+) by the electrostatic force generated by the electric field generated by the voltage applied between the (+) (-) electrode plates 16A and 16B of the electrostatic separator 12 falls downward while (- In the direction of the electrode, the negatively charged powder falls in the downward direction, moves in the direction of the (+) electrode, and is moved by the central separator 14 positioned in the center of the (+) (-) electrode plates 16A and 16B. The yield is controlled by a separate and rotatable yield control plate (13). In addition, to prevent the charged powder from adhering to the surfaces of the electrode plates 16A and 16B and weakening the electric field strength, the charged powder is struck and attached to the thrust hammer 19 connected to the rotating rods 20A and 20B which rotate 1 to 5 times per minute. Remove the powder. The fine powder separated in the positive (+) (-) electrode direction in the electrostatic separator 12 is collected in the cyclones 22A, 22B.

The apparatus of the present invention will be described in detail as follows.

A low pressure blower air (air pressure 1000 to 5000 mmAq) is introduced into the air inlet 1 for fine powder input and charging, and fine powder is injected into the fine powder inlet 3. The charged air and the fine powder are accelerated in the fine powder mixing nozzle 4 and then rubbed and collided in the fine powder mixing part 2 to give strong charging. The material of the fine powder mixing part 2 is made of stainless steel (or ceramic). It is made of material.

Charged powder of stainless steel (or ceramic) material is spread so that the charged powder introduced into the charged powder inlet 8 is uniformly spread in the width direction while passing through the charged powder induction blade 9 and uniformly injected into the electrostatic separator 12. The unit 10 installs the charged powder induction wing 9 therein.

The increase in the fine powder treatment capacity using the fine powder mixing section 2 and the charged powder diffusion section 10 is due to the limitation of the processing capacity per length of the unit electrode plates 16A and 16B, as shown in FIG. The horizontal width extension and the parallel installation of the unit electrode plates 16A and 16B are used. In order to increase the width of the parallel plate type electrode plates 16A and 16B in the horizontal direction, the charged powder diffusion part 10 increases the number of charged powder inducing vanes 9 and expands the width in the horizontal direction of the charged powder injection hole 11. It is possible to easily increase the capacity of the charged powder diffusion portion 10, and can easily increase the fine powder processing capacity by installing the charged powder diffusion portions 10 in parallel when the unit electrode plates 16A and 16B are installed in parallel. have. Further, by using only one of the fine powder mixing nozzles 4 and the fine powder mixing unit 2 to increase its size, the fine powder processing capacity can be increased.

The charged powder injection hole 11 is configured to adjust the outlet width to 4 to 8 mm so as to separate the charged powder well, and breaks down the insulation between the electrode plates 16A and 16B, which are high voltage applied portions of the electrostatic separator 12. In order to prevent the use of acrylic, epoxy or Teflon as a material or coated with Teflon on the outside of the steel can be used.

The electrostatic separator 12 for separating the charged powder is provided with electrode plates 16A and 16B made of copper or stainless steel at intervals of 10 cm, and applied with a voltage to apply an electric field of 1 to 10 KV /. It was made to be adjustable in cm. The thrust plate 18 on the top of the electrode plates 16A and 16B is struck with a thrust hammer 19 connected to the rotating rod 20 rotating 1 to 5 times per minute to remove the charged powder attached to the electrode plates 16A and 16B. In addition, in order to prevent discharge between the electrode plates 16A and 16B and the central separator 14 and to uniformly flow the suction air and the charged powder, the upper and lower parts of the electrode plates 16A and 16B (the central separator 14 ) And the insulating plates 15A and 15B.

In order to adjust the yield of the charged powder, the yield control plate 13 installed in the center between the electrode plates 16A and 16B was installed at 10 to 15 cm below the charged powder injection hole 11 to enable easy yield control. The yield control plate 13 can be controlled by manual operation and electric motor to move about 2.5cm from side to side.

The separated powder is introduced into the cyclones 22A and 22B by the suction force of the bag filters (B / F) 25A and 25B and collected, and collected using the fine powder collecting ports 23A and 23B.

Reference numeral 6 is a raw material hopper, 17 is an electrostatic separator enclosure, 7A, 7B is a drive motor, 21 is a spring, 24A, 24B is an air outlet, and 26, 27, 28, and 29 in FIG. 8 describe the prior art. For the purpose of reference, 26 is a rotating frictional charging agent, 27 is an electrostatic separator, 28 is a cyclone and a powder collecting port, and 29 is a raw material inlet.

Example 1

Under operating conditions of input air pressure 0.2kgf / cm ² , electrode spacing 10cm, and applied voltage 45kV, 270kg / hr and 300kg / hr coal ash with 7.0% unburned carbon content was introduced. It is shown in the figure. The yield of coal ash with unburned carbon content of less than 3% was found to be refinable at about 70% at 270 kg / hr and 65% at 300 kg / hr.

First, in the apparatus of the prior art (Patent Application No. 97-68549), the fine powder was first charged by compressed air in the fine powder mixing unit, and then the second charged in the rotary frictional charger. In this case, there is a disadvantage in that the structure and operation of the device are complicated due to the presence of a rotary blade and a driving unit rotating at a high speed, but the device of the present invention uses a fine powder mixing unit using low pressure air, a charge powder conveying tube, and a charge powder diffusion unit. The first charging in the fine powder mixing section, the second charging through the mixed powder conveying pipe, and finally the charging again in the charging powder diffusion section, it is a simple charging device with excellent charging efficiency and no driving unit and driving device. In the case of fine powder mixed nozzles using compressed air, the agglomeration of fine powder is prevented by high compressed air (air pressure of 10000mmAq or more). Although the charge of the fine powder increases, the initial investment cost for the installation of the compressed air generating device increases as the capacity of the device increases, and the processing cost such as the power cost according to the fine powder treatment takes a lot of disadvantages, but in the present invention, blower air, which is low pressure air, is used. By adopting fine powder mixing nozzle using air pressure 1000 ~ 5000mmAq and charging and transporting, the device is simple, so the initial investment cost is small, powder processing cost per unit weight is low, and third, electrode plate which is a conventional method of increasing powder processing capacity. In the case of the width expansion method, the number of raw material input devices increases or the input device lengthens in the width direction, and the rotary frictional charging device increases in the width direction, making the device complicated and difficult to repair. The role of spreading the fine powder injected from the part evenly in the width direction of the electrode plate In order to improve the capacity, the charged powder diffusion part installed with the charged powder induction wing is suitable for increasing the capacity. Fourth, the conventional method of removing the powder with the electrode plate using the brush and the air cylinder is the brush support rod and the air when the fine powder treatment capacity is increased. The length of the cylinder is increased and the number is increased, which complicates the device. However, in the present invention, after the insulating plate is coupled to the upper part of the electrode plate, the thrust plate is struck with a tumble hammer to remove the charged powder attached to the electrode plate by the vibration. It is easy to decorate the device even when it is increased, and the insulating plate is attached to the upper and lower part of the electrode plate (the part facing the central separator plate) to prevent the discharge between the electrode plate and the center separator plate and to make the flow of intake air and charged powder uniform. Fifth, increase the width of the electrode plate in the horizontal direction and expand the unit cells of the parallel When the capacity is increased, the processing capacity can be easily increased by connecting the charged powder diffusion part and the charged powder injection port as many parallel unit cells as the one powder mixing nozzle and the powder mixing part having increased processing capacity. The yield control plate installed on the upper part of the separator plate was moved about 2.5cm from side to side by using a manual and electric motor to easily adjust the yield.

Claims (5)

The fine powder naturally introduced by the expansion of the low pressure blower air (air pressure 1000 to 5000 mmAq) is accelerated in the fine powder mixing nozzle 4 and the particles and particle collide by the strong stirring in the fine powder mixing part 2, the particles and the wall It is first charged by collision with the same method and uniformly charged in the electrostatic separator 12 perpendicular to the aerosol state after the second charge in the charged powder transfer pipe 5 and the third charged and diffused in the charged powder diffusion part 10. The fine powder separation method using the airflow collision triboelectric electrostatic separation method that separates the charged powder moved in the (+) (-) electrode direction according to the charge polarity by the central separator 14, respectively. The airflow impact friction type electrostatic separation method according to claim 1, wherein the charged powder is passed through the charged powder diffusion portion 10 and the charged powder induction blade 9 so as to uniformly insert the charged powder into the electrostatic separator 12. Fine powder separation method using. The thrust plate on the top of the electrode plates 16A and 16B according to claim 1, wherein the charged powder attached to the electrode plates 16A and 16B weakens the electric field strength. 18) to remove the charged powder adhering to the electrode plates 16A and 16B, and to prevent the discharge between the electrode plates 16A and 16B and the central separator plate 14 and to uniformly flow the intake air and the charged powder. In order to improve the fine powder separation performance by installing the insulating plates (15A, 15B) in the upper and lower parts (facing the central separation plate) of the electrode plate (16A, 16B), Fine powder separation method using. Air inlet 1 for injecting low pressure blower air (air pressure 1000-5000Aq), fine powder inlet 3 for injecting fine powder, fine powder mixing nozzle 4 for accelerating fine powder, strong stirring of low pressure air and fine powder The fine powder mixed part (2) made of stainless steel, which is entangled by and causes the fine powder to be strongly charged by friction and collision between the fine powders and the wall of the fine powder and the fine powder mixing part (2), the fine powder is again charged The charged powder diffusion part 10 to evenly distribute the charged powder introduced from the charged powder conveying tube 5, the charged powder diffusion part 10, and the fine powder mixing part 2 in the width direction of the electrode plates 16A and 16B. In order to drop the charged powder attached to the electrode plates 16A and 16B, respectively, the charged powder induction blades 9 are provided inside the thrust plate 18 on the electrode plates 16A and 16B 1 to 5 times per minute. Install the thrust hammer (19) which can be struck, the electrode plate (16A, 16B) Airflow collision, characterized in that insulating plates 15A and 15B are provided on the upper and lower portions of the electrode plates 16A and 16B to prevent discharge between the central separator 14 and to uniformly flow the suction air and the charged powder. Fine powder separator using triboelectric static separation method. 5. The method of claim 4, wherein the width of the electrode plates 16A, 16B is extended, the width of the charged powder diffusion unit 10 is expanded, and the fine powder mixing nozzle 4 and the fine powder are mixed to increase the fine powder processing capacity. Separation of fine powder using an airflow collision triboelectric electrostatic separation method characterized by increasing the number of charged powder diffusion units 10 in parallel when increasing the dimensions of the part 2 and increasing the capacity of additionally installing electrode plates in parallel. Device.