JP2011156472A - Particle separation apparatus and particle separation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a particle separation apparatus and a particle separation method for separating two or more kinds of particles. <P>SOLUTION: The particle separation apparatus 1 is used for separating particles 51, 52, 53 in liquid and includes a PH adjusting gas supply part 3 for supplying CO<SB>2</SB>fine bubbles 61 for adjusting a pH value V to particle-containing liquid 54, a PH value detection part 6 for detecting and outputting the pH value V of the particle-containing liquid 54 and a control part 7 for controlling the PH adjusting gas supply part 3 based on the pH value V input from the PH value detection part 6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a particle separation device and a particle separation method for separating fine particles in a liquid.

  A particle separation apparatus and method for separating particles such as filth contained in waste water are known. Patent Document 1 discloses a technique for separating particles in a liquid with fine bubbles. Specifically, the technique of Patent Document 1 supplies fine bubbles of carbon dioxide into the liquid in the separation tank. As a result, the fine bubbles adhere to the particles in the liquid, and the fine bubbles and the particles in the liquid float on the surface of the liquid. As a result, the technique of Patent Document 1 separates particles. Non-Patent Document 1 discloses a technique for floating and separating iron oxide in a liquid using microbubbles.

JP 2009-56426 A

Koichi Terasaka, “Application to the chemical industry using the surface properties of microbubbles”, Proceedings of the 3rd Micro-Nano Bubble Technology Symposium, 3rd Micro-Nano Bubble Technology Symposium, December 14, 2007, p18-22

  However, the techniques of Patent Document 1 and Non-Patent Document 1 have a problem that only one type of particle can be separated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a particle separation apparatus and a particle separation method that can separate a plurality of types of particles.

  In order to achieve the above object, the invention according to claim 1 is a particle separation apparatus for separating particles in a liquid, wherein pH is supplied to the liquid with fine bubbles of a pH adjusting gas for adjusting a pH value. Based on the pH value input from the adjustment gas supply unit, the pH value detection means for detecting and outputting the pH value of the liquid, and the pH value input from the pH value detection means, the pH adjustment supplied by the pH adjustment gas supply unit And a control unit that controls the supply amount of fine bubbles of the working gas.

  The invention according to claim 2 further includes an attached gas supply unit that supplies fine bubbles of the attaching gas that adheres to the particles, and the control unit controls the attached gas supply unit to control the inside of the liquid. It is characterized by supplying the fine bubbles for adhesion to be supplied to the substrate.

  Moreover, the invention according to claim 3 has a storage unit in which the control unit stores a separation pH value at which an adhesion gas can be attached to particles to be separated in association with the particles to be separated, The control unit supplies the pH adjusting gas by controlling the pH adjusting gas supply unit so as to be the separation pH value.

  In the invention according to claim 4, the pH adjustment gas supply unit supplies a first pH adjustment gas supply unit that supplies gas fine bubbles for acidifying the liquid, and gas fine bubbles for alkalinizing the liquid. And a second pH adjusting gas supply unit.

  The invention according to claim 5 is the particle separation method for separating the particles in the liquid, the attachment gas supply step for supplying the attachment gas to be attached to the particles, the first particles to be separated, A first supply step of supplying fine bubbles of pH adjusting gas into the liquid containing the second particles, and the pH adjustment when the pH value of the liquid becomes the first separation pH value where the adhering gas adheres to the first particles. A first stop step for stopping the supply of the fine gas bubbles, a second supply step for supplying the fine bubbles of the pH adjusting gas into the liquid containing the second particles to be separated, and the pH value of the liquid is second. And a second stop step of stopping the supply of fine bubbles of the pH adjusting gas when the second separation pH value at which the attaching gas adheres to the particles is obtained.

  The invention according to claim 6 is characterized in that after the first stop step is completed, the first supply step and the first stop step are repeated in accordance with a decrease in the pH adjusting gas.

  According to the present invention, the control unit controls the supply amount of the pH adjusting gas based on the pH value of the liquid. Thereby, a plurality of types of particles can be separated separately by setting the supply amount of the pH adjusting gas for each particle so that the pH value allows the adhesion gas to adhere to the particles to be separated. .

1 is an overall configuration diagram of a particle separator according to a first embodiment. It is a graph of the zeta potential of the separated particles and the pH adjusting gas and the pH value of the liquid. It is a flowchart for demonstrating a particle separation program. It is a figure explaining the state from which different particles float in order. It is a figure explaining the state from which different particles float in order.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a particle separator according to a first embodiment. FIG. 2 is a graph of the zeta potential of the separated particles and the pH adjusting gas and the pH value of the liquid.

  The particle separation device 1 according to the first embodiment is for separating particles 51, 52, and 53 of a particle-containing liquid 54. The particle 51 is a particle mainly made of silica dioxide, the particle 52 is a particle mainly made of carbon, and the particle 53 is kaolin. As shown in FIG. 1, the particle separation device 1 according to the first embodiment includes a separation tank 2, a pH adjustment gas supply unit 3, an attached gas supply unit 4, a recovery mechanism 5, a pH value detection unit 6, And a control unit 7.

  The separation tank 2 is for storing a particle-containing liquid (corresponding to a liquid in claims) 54 including three kinds of particles 51, 52, 53 to be separated.

  The pH adjusting gas supply unit 3 is for supplying the fine bubbles 61 of carbon dioxide (the pH adjusting gas in claims) to the particle-containing liquid 54. Here, the fine bubbles 61 of carbon dioxide adjust the pH value V of the particle-containing liquid 54 and have a function of adhering to and floating on the particles 51 and 53. The pH adjustment gas supply unit 3 includes a tank 11, a pipe 12, a valve 13, a fine bubble generating device 14, a pipe 15, and a supply unit 16.

  The tank 11 is for storing carbon dioxide for supply.

  The piping 12 allows carbon dioxide to flow from the tank 11 to the fine bubble generating device 14. The pipe 12 connects the tank 11 and the fine bubble generating device 14.

  The valve 13 is for adjusting the amount of carbon dioxide supplied to the fine bubble generating device 14. The valve 13 is disposed in the middle of the pipe 12.

  The fine bubble generating device 14 generates the fine bubbles 61 from the carbon dioxide supplied from the tank 11. The fine bubbles 61 are microbubbles having a diameter of 1 mm or less or nanobubbles having a diameter of 1 μm or less. The fine bubble generating device 14 has a water supply pipe 14a to which water is supplied. The microbubble generator 14 supplies the microbubbles 61 to the supply unit 16 together with water.

  The pipe 15 allows the fine bubbles 61 to flow from the fine bubble generating device 14 to the supply unit 16. The pipe 15 connects the fine bubble generating device 14 and the supply unit 16.

  The supply unit 16 supplies the fine bubbles 61 supplied from the fine bubble generating device 14 to the particle-containing liquid 54 via the pipe 15.

  The attached gas supply unit 4 is for supplying fine air bubbles 62 of neutral air (attaching gas in claims) to the particle-containing liquid 54. Here, the fine air bubbles 62 have a function of adhering to and floating on the particles 51 and 53 in the particle-containing liquid 54. The attached gas supply unit 4 includes a tank 21, a pipe 22, a valve 23, a fine bubble generating device 24, a pipe 25, and a supply unit 26.

  The tank 21 is for storing supply air.

  The pipe 22 allows air to flow from the tank 21 to the fine bubble generating device 24. The pipe 22 connects the tank 21 and the fine bubble generating device 24.

  The valve 23 is for adjusting the amount of air supplied to the fine bubble generating device 24. The valve 23 is disposed in the middle of the pipe 22.

  The fine bubble generating device 24 generates fine bubbles 62 from the air supplied from the tank 21. The fine bubbles are micro bubbles or nano bubbles. The fine bubble generating device 24 has a water supply pipe 24a to which water is supplied. The fine bubble generating device 24 supplies the fine bubbles 62 to the supply unit 26 together with water.

  The piping 25 allows the fine bubbles 62 to flow from the fine bubble generating device 24 to the supply unit 26. The pipe 25 connects the fine bubble generating device 24 and the supply unit 26.

  The supply unit 26 supplies the fine bubbles 62 supplied from the fine bubble generating device 24 to the particle-containing liquid 54 via the pipe 23.

  The recovery mechanism 5 is for recovering the particles 51 and 53 that have floated on the upper surface of the particle-containing liquid 54. The recovery mechanism 5 is not particularly limited, but a suction mechanism such as a vacuum can be employed.

  The pH value detection unit 6 detects the pH value V of the particle-containing liquid 54 and outputs it to the control unit 7. The pH value detection unit 6 may be a general pH meter such as a glass electrode type.

  The control unit 7 is responsible for overall control of the particle separation apparatus 1. The control unit 7 includes a calculation unit 31, a storage unit 32, and a connection unit 33.

  The calculation unit 31 is for executing various programs such as a particle separation program described later. The computing unit 31 is composed of a CPU (central processing unit).

The storage unit 32 stores various numerical information and programs such as a particle separation program. The storage unit 32 includes a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and the like. The numerical information stored in the storage unit 32 includes a table shown in Table 1 in which the adhesion target particles 51 and 53 and the separation pH values Va and Vb are associated with each other. Here, the separation pH value Va is a pH value at which the fine air bubbles 62 adhere to the particles 51 to be separated. The separation pH value Vb is a pH value at which the fine air bubbles 62 adhere to the particles 53 to be separated.

  Therefore, when the particles 51 are separated, the flow rate of carbon dioxide is controlled via the valve 13 so that the pH value V becomes the separation pH value Va. When the particles 53 are separated, the flow rate of carbon dioxide is controlled via the valve 13 so that the pH value V becomes the separation pH value Vb.

  Next, a method for associating the separated pH values Va and Vb with the particles 51 and 53, that is, a method for creating the table of Table 1 will be described. It is known that the zeta potential of particles and the zeta potential of gases (such as carbon dioxide) vary with the pH value V of the surroundings (particle-containing liquid 54). FIG. 2 shows the result of examining this by experiment. In FIG. 2, the horizontal axis indicates the pH value of the surroundings (for example, a particle-containing liquid), and the vertical axis indicates the zeta potential of particles or air at each pH value.

Here, in order to attach the fine air bubbles 61 to the particles 51 and 53 to be separated,
(Condition 1) The sign of the zeta potential of air is opposite to the sign of the zeta potential of the particles 51 and 53 to be separated. (Condition 2) The absolute value of the zeta potential of air and the zeta of the particles 51 and 53 to be separated. A preferable condition is that the absolute value of the potential is substantially equal. Therefore, the separation pH values Va and Vb satisfying the conditions 1 and 2 are associated with the particles 51 and 53 to be separated. The result is the table in Table 1. As can be seen from FIG. 2, for example, the particle 51 has a separation pH value Va of about 5.5. The particles 53 have a separation pH value Vb of about 3.2. The particles 52 are collected together with the particle-containing liquid 54 because it is difficult to adhere by air. Here, the above-described conditions are examples, and can be changed as appropriate.

  The connection part 33 is connected with the valve | bulb 13 so that an instruction | indication signal can be transmitted. Thereby, the control unit 7 controls the supply amount of carbon dioxide by the valve 13. The connection unit 33 is connected to the fine bubble generating device 14 so as to transmit an instruction signal. Thereby, the control part 7 controls the fine bubble production | generation apparatus 14, and switches supply and the stop of the fine bubble 61 of a carbon dioxide.

  The connection part 33 is connected with the valve | bulb 23 so that an instruction | indication signal can be transmitted. Thereby, the control unit 7 controls the supply amount of air by the valve 23. The connection unit 33 is connected to the fine bubble generating device 24 so that an instruction signal can be transmitted. Thereby, the control part 7 controls the fine bubble production | generation apparatus 24, and switches supply and a stop of the fine bubble of air.

  The connection unit 33 is connected to the pH value detection unit 6 so as to receive the pH value V. Thereby, the control unit 7 controls the valve 13 of the pH adjustment gas supply unit 3 so that the detected pH value V of the particle-containing liquid 54 becomes the set separation pH values Va and Vb.

  The connection part 33 is connected with the collection | recovery mechanism 5 so that an instruction | indication signal can be transmitted. Thus, the control unit 7 collects the particles 51 and 53 that have been levitated by the collection mechanism 5.

(Operation according to the first embodiment)
Next, a particle separation method for separating particles in the particle-containing liquid by the particle separation device 1 of the first embodiment will be described. The particle separation method will be described along with a particle separation program executed by the control unit 7. FIG. 3 is a flowchart for explaining the particle separation program. 4 (a) and 4 (b) are diagrams illustrating a state in which different particles float in order.

  First, as illustrated in FIG. 3, when the particle-containing liquid 54 is drained into the separation tank 2, the control unit 7 causes the fine bubbles 61 of carbon dioxide to be contained in the particle-containing liquid 54 including the particles 51 to 53 to be separated. Supply (S1). Specifically, the control unit 7 opens the valve 13 and supplies the carbon dioxide in the tank 11 to the fine bubble generating device 14. Thereafter, the control unit 7 controls the fine bubble generating device 14 to generate the fine bubbles 61 of carbon dioxide, and the fine bubbles 61 are supplied from the supply unit 16 to the particle-containing liquid 54 together with the water supplied from the water supply pipe 14a. Supply. As a result, the pH value V of the particle-containing liquid 54 gradually decreases, that is, becomes acidic.

  Next, the control unit 7 determines whether or not the pH value V input from the pH value detection unit 6 is the separated pH value Va stored in the storage unit 32 (S2). The controller 7 repeats the process of step S2 until the pH value V reaches the separation pH value Va (S2: No).

  Next, when the control unit 7 determines that the pH value V of the particle-containing liquid 54 has reached the separation pH value Va (S2: Yes), the control unit 7 stops supplying the fine bubbles 61 of carbon dioxide (S3). Specifically, the control unit 7 closes the valve 13 and stops the fine bubble generating device 14.

  Next, the control unit 7 supplies the fine air bubbles 62 to the particle-containing liquid 54 (S4). Specifically, the control unit 7 opens the valve 13 and supplies the air in the tank 21 to the fine bubble generating device 24. Thereafter, the control unit 7 controls the fine bubble generating device 24 to generate air fine bubbles 62 and supplies the fine bubbles 62 from the supply unit 26 to the particle-containing liquid 54 together with the water supplied from the water supply pipe 24a. To do. As a result, as shown in FIG. 2, many carbon dioxide microbubbles 61 and air microbubbles 62 are particles 51 having opposite zeta potential signs and equal absolute values, and particles contained in the particle-containing liquid 54. It sticks around 51. For this reason, as shown in FIG. 4A, the particles 51 float on the liquid surface. On the other hand, when the pH value V of the particle-containing liquid 54 is the separation pH value Va, since the fine bubbles 61 and 62 hardly adhere to the particles 52 and 53, the particles 52 and 53 do not float so much.

  Next, the control unit 7 determines whether or not the separation time has elapsed (S5). Here, the separation time is a time required to separate the particles 51 contained in the particle-containing liquid 54, which is determined empirically.

  Next, the control part 7 repeats the process of step S1-step S5 until separation time passes (S5: No). By repeating this, the fine bubbles 61 of carbon dioxide are supplied in accordance with the carbon dioxide that has been reduced by adhering to the particles 51, and the particles 51 contained in the particle-containing liquid 54 are maintained while maintaining the pH value V at the separation pH value Va. Make it rise.

  Next, when it is determined that the separation time has elapsed (S5: Yes), the control unit 7 stops the supply of the fine air bubbles 61 (S6).

  Next, the control unit 7 collects the particles 51 that have been levitated by the collection mechanism 5 (S7).

  Next, the control part 7 floats and collect | recovers the particle | grains 53 by the process of step S8-step S14. The processes in steps S8 to S14 are the same as the processes in steps S1 to S7, and will be described in a simplified manner.

  The control unit 7 supplies the fine bubbles 61 of carbon dioxide to the particle-containing liquid 54 including the particles 52 and 53 (S8). Next, when the pH value V of the particle-containing liquid 54 reaches the separation pH value Vb (S9: Yes), the control unit 7 stops the supply of the carbon dioxide fine bubbles 61 (S10). Thereafter, the control unit 7 supplies fine air bubbles 62 (S11). The control unit 7 repeats the processes of steps S8 to S12 until the separation time elapses. Thereby, as shown in FIG.4 (b), the fine bubbles 61 and 62 adhere to the particle | grains 53, and the particle | grains 53 float on the liquid level.

  Next, when the control unit 7 determines that the separation time has elapsed (S12: Yes), the control unit 7 stops the supply of the fine air bubbles 62. Thereafter, the control unit 7 collects the particles 53 floating on the liquid surface by the collection mechanism 5.

  Thereby, the control part 7 complete | finishes a particle separation program.

(Effect of 1st Embodiment)
Next, effects of the particle separation device 1 and the particle separation method according to the first embodiment described above will be described.

  As described above, in the particle separation device 1 according to the first embodiment, the control unit 7 adjusts the pH value V of the particle-containing liquid 54 by controlling the fine bubbles 61 of carbon dioxide supplied from the fine bubble generating device 14. it can. Thereby, the adhesion efficiency of the particles 51 and 53 and the fine bubbles 62 can be improved. As a result, the particle separation apparatus 1 can promptly float the particles 51 and 53 and shorten the separation time.

  Further, in the particle separation device 1, the control unit 7 sets the pH value V of the particle-containing liquid 54 to the separation pH values Va and Vb in order by adjusting the supply amount of the fine bubbles 61 of carbon dioxide. Thereby, the particle | grain separation apparatus 1 can isolate | separate different particle | grains 51 and 53 separately, without using the additive for pH adjustment, etc.

  Moreover, since the particle | grain separation apparatus 1 supplies the fine bubble 62 of the air adhering to particle | grains 51 and 53 by the fine bubble production | generation apparatus 24, the particle | grains 51 and 53 can be floated more rapidly.

  In the particle separation device 1, the control unit 7 controls the fine bubbles 61 of carbon dioxide based on the pH value V detected by the pH detection unit 6 so that the pH value V becomes the separation pH values Va and Vb. Supply. Thereby, since the particle separator 1 can maintain the pH value V of the particle-containing liquid 54 substantially constant, the adhesion efficiency between the particles 51 and 53 and the fine bubbles 61 and 62 can be improved.

  As mentioned above, although this invention was demonstrated in detail using embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims. Hereinafter, modified embodiments in which the above-described embodiment is partially modified will be described.

  The shape, material, numerical value, arrangement, and the like of each component in the above-described embodiment can be changed as appropriate. The order of the steps in the above-described embodiment can be changed as appropriate. For example, changing the order of the step of supplying air (adhesion gas) and the step of supplying and stopping the supply of carbon dioxide can be raised.

  Moreover, in embodiment mentioned above, although pH value was adjusted with the carbon dioxide, you may adjust pH value with other gas, such as nitrogen dioxide and ammonia. Further, the pH value of the liquid may be adjusted by two or more kinds of gases. For example, the pH adjustment gas supply unit of the particle separator includes a first pH adjustment gas supply unit that acidifies the liquid with carbon dioxide fine bubbles and a second pH adjustment gas supply unit that alkalizes the liquid with ammonia fine bubbles. You may have. Thereby, the particle separation device can make the liquid acidic or alkaline, and facilitates fine adjustment of the pH value. Here, it is preferable that the acidic gas and alkaline gas supplied in order to adjust pH are determined in consideration of mutual reactivity according to the use situation. For example, a combination in which the mutual gases hardly react (or does not react), and conversely, a combination in which the mutual gases easily react can be considered.

  Further, in the above-described embodiment, as particles to be adsorbed, particles made mainly of carbon dioxide such as combustion ash and kaolin are given as examples, but these are examples, and the particles to be adsorbed can be appropriately changed. is there.

  In the particle separation method described above, the process of each step is executed by the control unit. However, the user may execute the process of each step.

  In the embodiment described above, the adhesion gas supply unit is provided, but the pH adjusting gas and the adhesion gas may be configured by the same gas, and the adhesion gas supply unit may be omitted.

DESCRIPTION OF SYMBOLS 1 Particle separator 2 Separation tank 3 pH adjustment gas supply part 4 Adhered gas supply part 5 Recovery mechanism 6 pH value detection part 7 Control part 11 Tank 12, 15 Pipe 13 Valve 14 Fine bubble production | generation apparatus 16 Supply part 21 Tank 22 Pipe 23 Valves 23 and 25 Pipe 24 Fine bubble generating device 26 Supply units 51, 52 and 53 Particles 54 Particle-containing liquid (liquid)
61 Fine bubbles of carbon dioxide (fine bubbles of gas for pH adjustment)
62 Air microbubbles (adhesive gas microbubbles)
V pH value Va Separation pH value Vb Separation pH value

Claims (6)

In a particle separator for separating particles in a liquid,
a pH adjusting gas supply unit for supplying fine liquid bubbles of a pH adjusting gas for adjusting the pH value to the liquid;
PH value detection means for detecting and outputting the pH value of the liquid;
Particle separation comprising: a control unit that controls a supply amount of fine bubbles of the pH adjusting gas supplied by the pH adjusting gas supply unit based on a pH value input from the pH value detecting means apparatus. An adhesion gas supply unit for supplying fine bubbles of the adhesion gas adhering to the particles;
The particle separation device according to claim 1, wherein the control unit controls the adhesion gas supply unit to supply adhesion fine bubbles to be supplied into the liquid. The control unit includes a storage unit in which a separation pH value at which an adhesion gas can adhere to particles to be separated is stored in association with the particles to be separated;
The particle separation apparatus according to claim 1, wherein the control unit supplies the pH adjusting gas by controlling the pH adjusting gas supply unit so as to be the separation pH value. The pH adjustment gas supply unit
A first pH adjusting gas supply unit for supplying fine gas bubbles for acidifying the liquid;
The particle separation device according to any one of claims 1 to 3, further comprising a second pH adjusting gas supply unit that supplies fine bubbles of a gas that makes the liquid alkaline. In a particle separation method for separating particles in a liquid,
An adhesion gas supply step for supplying an adhesion gas to be adhered to the particles;
A first supply step of supplying fine bubbles of a gas for pH adjustment into a liquid containing first particles and second particles to be separated;
A first stop step of stopping the supply of fine bubbles of the gas for pH adjustment when the pH value of the liquid reaches the first separation pH value at which the gas for adhesion adheres to the first particles;
A second supply step of supplying fine bubbles of pH adjusting gas into the liquid containing the second particles to be separated;
A second stop step of stopping the supply of fine bubbles of the gas for pH adjustment when the pH value of the liquid reaches the second separation pH value at which the gas for adhesion adheres to the second particles. Separation method.   6. The particle separation method according to claim 5, wherein after the first stop step, the first supply step and the first stop step are repeated in accordance with a decrease in the pH adjusting gas.