JP2021084067A - Dispersion system for solid-liquid mixture - Google Patents

Abstract

To provide a solid-liquid dispersion system capable of more effectively dispersing fine particles in various combinations of fine particles with a liquid.SOLUTION: A solid-liquid mixture dispersion system 10 comprises: a rotor-stator type dispersion device 18; a circulation path 25 circulating a solid-liquid mixture; ultrasonic homogenizer units 14, 20 provided to the circulation path 25; a viscometer 31 provided to the path 25 to detect the viscosity of the mixture; and a controller 34 controlling the operations of the rotor-stator type dispersion device 18 and ultrasonic homogenizer units 14, 20. The controller 34 operates selectably the rotor-stator type dispersion device 18 only, the rotor-stator type dispersion device 18 and ultrasonic homogenizer units 14, 20, and the ultrasonic homogenizer units 14, 20 only in response to the viscosity value detected by the viscometer 31.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solid-liquid dispersion system that mixes and disperses powder and liquid.

As a solid-liquid mixing and dispersing system that mixes and disperses powder into a liquid to generate a suspension, a solid-liquid mixing and dispersing system that produces a turbid liquid through a plurality of rotors, a stator mixer, and a dispersion device is known. Further, a method of efficiently generating a turbid liquid by circulating a mixed liquid of powder and liquid between a storage tank and a dispersion device has also been proposed (Patent Document 1).

Japanese Patent No. 6388501

However, in the conventional solid-liquid mixing and dispersion system, a suspension of sufficient quality could not be obtained depending on the combination of powder and liquid. For example, in a disperser using a rotor and a stator, if the rotor is rotated at high speed to promote dispersion, the powder may be destroyed and the quality of the suspension may be deteriorated. On the other hand, if the rotor is rotated at a low speed so that the powder is not destroyed, the powder may not be sufficiently uniformly dispersed and the required dispersion level may not be obtained.

An object of the present invention is to provide a solid-liquid dispersion system capable of more effectively dispersing powders in various combinations of powders and liquids.

The solid-liquid mixing / dispersing system according to the first invention of the present invention is a solid-liquid dispersion system that mixes and disperses a powder and a liquid, and has a supply port to which a mixed liquid of the powder and the liquid is supplied. A dispersion device having a dispersion chamber for mixing and dispersing the supplied mixed liquid by a rotor and a stator, and a discharge port for discharging the mixed and dispersed mixed liquid, and the discharge port and the supply port are communicated with each other. A circulation passage for circulating the mixed liquid discharged from the disperser to the supply port, an ultrasonic homogenizer provided in the circulation passage, and a viscosity detecting means provided in the circulation passage for detecting the viscosity of the mixed liquid. The disperser and the control means for controlling the operation of the ultrasonic homogenizer are provided, and the control means only the disperser according to the value of the viscosity detected from the viscosity detecting means, the disperser and the ultrasonic wave. It is characterized in that only the homogenizer and the ultrasonic homogenizer can be selectively operated.

The solid-liquid mixing / dispersing system according to the second aspect of the present invention is characterized in that, in the first invention, a plurality of the ultrasonic homogenizers are provided and the operation of each ultrasonic homogenizer can be controlled.

The solid-liquid mixing / dispersing system according to the third aspect of the present invention is characterized in that, in the second invention, the ultrasonic homogenizers are provided in parallel.

In the solid-liquid mixing / dispersing system according to the fourth aspect of the present invention, in the first to third inventions, the ultrasonic homogenizer includes a holder that covers the ultrasonic irradiation horn, and the holder is a lower intake port for the mixed liquid. Is formed, and a mixture outlet is formed on the side.

According to the present invention, it is possible to provide a solid-liquid dispersion system capable of more effectively dispersing powders for various combinations of powders and liquids.

It is a block diagram which shows the whole structure of the solid-liquid dispersion system which is one Embodiment of this invention. It is a block diagram which shows the overall structure of the 1st and 2nd ultrasonic homogenizer units. It is a vertical sectional view of an ultrasonic homogenizer. It is a partially enlarged vertical sectional view of an ultrasonic homogenizer centered on a holder. It is a top view which shows the radial arrangement of an irradiation horn and a holder. It is a graph which shows the viscosity change of the mixed liquid in the dispersion processing of this embodiment, and the driving state of the rotor stator type dispersion apparatus, the 1st and 2nd ultrasonic homogenizer units. It is a block diagram which shows the overall structure of the 1st and 2nd ultrasonic homogenizer units in the modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an overall configuration of a solid-liquid dispersion system according to an embodiment of the present invention.

The solid-liquid dispersion system 10 of the present embodiment mixes a powder (for example, a conductive auxiliary agent such as graphite) and a liquid (for example, a binder solution), and circulates the mixed solution to form a slurry. The liquid is supplied to the tank 12, and the liquid in the tank 12 is sent to the first ultrasonic homogenizer unit 14. A pump 16 is connected downstream of the first ultrasonic homogenizer unit 14, and a rotor stator type disperser 18 having a rotor 18A and a stator 18B is connected downstream of the pump 16. A liquid (or a mixed liquid) is supplied to the rotor stator type disperser 18 from the inlet portion (supply port) 18C via the pump 16, and powder is supplied as described later. The mixed liquid in which the liquid and the powder are mixed by the rotor stator type disperser 18 is sent out from the outlet portion (discharge port) 18E, and is sent to the tank 12 via the second ultrasonic homogenizer unit 20 and the cooler 22. , Returned to tank 12.

That is, the same path constitutes the circulation passage 25, and the mixed liquid is supplied by the pump 16, the tank 12, the first ultrasonic homogenizer unit 14, the pump 16, the rotor stator type disperser 18, the second ultrasonic homogenizer unit 20, and the cooler. Circulated between 22.

The first thermometer 24 is connected to the pipe between the first ultrasonic homogenizer unit 14 and the pump 16, and the second thermometer 26 is connected to the pipe between the rotor stator type disperser 18 and the second ultrasonic homogenizer unit 20. However, a third thermometer 28 is provided in the piping between the cooler 22 and the tank 12. Further, a flow meter 30 is provided in the pipe between the pump 16 and, for example, a vibration type viscometer (viscosity detecting means) 31 is provided in the pipe between the second ultrasonic homogenizer unit 20 and the cooler 22. ..

Signals from the first to third thermometers 24, 26, 28, the flow meter 30, and the viscometer 31 are sent to the control device (control means) 34, and the first and second ultrasonic homogenizer units 14, 20, and Lotus The drive of the thermometer type disperser 18 and the pump 16 is controlled by the control device 34. In the present embodiment, the pump 16 is controlled based on the signal of the flow meter 30, and the flow rate of the mixed liquid circulated through the circulation passage 25 is controlled to a predetermined value, and the first to third thermometers 24, 26, 28 The drive of the cooler 22 is controlled based on the signal. Further, as will be described later, in the present embodiment, the driving of the first and second ultrasonic homogenizer units 14 and 20 and the rotor stator type disperser 18 is controlled based on the signal from the viscometer 31.

The rotor stator type disperser 18 includes a rotor 18A rotatably arranged below the inside of the rotor stator type disperser 18. The rotor 18A includes a rotating shaft 19 that extends upward and rotates integrally with the rotor 18A. The rotating shaft 19 is provided with a screw 19A and a stirring blade 19B for premixing from above to below. That is, the rotor stator type disperser 18 includes an introduction portion in which the screw 19A is arranged, a premixing portion in which the stirring blade 19B is arranged, and a dispersion chamber 18D in which the rotor 18A and the stator 18B are arranged.

The powder is charged into the introduction portion from above the rotor stator type disperser 18. The powder charged into the introduction section is sent to the lower premix section by the screw 19A. The premixing section is provided with an inlet section (supply port) 18C of the rotor stator type disperser 18, and the liquid (or mixed solution) delivered from the pump 16 is supplied to the premixing section after passing through the inlet section 18C. In the premixing section, the powder supplied from the introduction section and the liquid supplied from the inlet section 18C are mixed by the stirring blade 19B and sent to the lower dispersion chamber 18D. The dispersion chamber 18D is provided with an outlet portion (discharge port) 18E, and the mixed liquid in which the powder is mixed and dispersed in the liquid by the rotor 18A and the stator 18B is sent to the second ultrasonic homogenizer unit 20 through the outlet portion 18E. Will be done.

FIG. 2 is a block diagram showing the overall configuration of the first and second ultrasonic homogenizer units 14 and 20.

The first and second ultrasonic homogenizer units 14 and 20 of the present embodiment each include a configuration in which a plurality of ultrasonic homogenizers 32 are connected in parallel. The ultrasonic homogenizer units 14 and 20 of the present embodiment shown in FIG. 2 are composed of, for example, four ultrasonic homogenizers 32 connected in parallel.

The ultrasonic homogenizer 32 includes a holder 32A into which a mixed solution is injected, and an ultrasonic generator 32B that generates ultrasonic waves having a predetermined frequency, intensity, and waveform. The mixed liquid is distributed and supplied to the holder 32A of each ultrasonic homogenizer 32, and the mixed liquid dispersed by ultrasonic waves in each holder 32A is rejoined and discharged.

Next, the configuration of the ultrasonic homogenizer 32 of the present embodiment will be described with reference to FIGS. 3 to 5. FIG. 3 is a vertical cross-sectional view of the ultrasonic homogenizer 32, and FIG. 4 is a partially enlarged vertical cross-sectional view of the ultrasonic homogenizer 32 centered on the holder 32A. Further, FIG. 5 is a plan view showing the radial arrangement of the irradiation horn 33D and the holder 32A of the ultrasonic homogenizer 32.

The ultrasonic wave generator 32B includes an ultrasonic oscillator 33A, an ultrasonic vibrator 33B, a booster 33C, and an irradiation horn 33D. The ultrasonic oscillator 33A generates a drive signal corresponding to a predetermined frequency, intensity, and waveform to be set, and supplies (applies) this to the ultrasonic oscillator 33B. The ultrasonic vibrator 33B vibrates by a drive signal from the ultrasonic oscillator 33A, and the ultrasonic vibration generated by the ultrasonic vibrator 33B is amplified in the booster 33C and transmitted to the irradiation horn 33D. As a result, the irradiation horn 33D is vibrated in the vertical direction along the axis at a predetermined frequency, intensity, and waveform. The irradiation horn 33D has, for example, a cylindrical shape, and its lower end is inserted into the holder 32A with its axis vertical.

The center of vibration of the irradiation horn 33D is held by the flange member 36 attached to the upper opening edge 34 of the holder 32A, and the irradiation horn 33D is fixed at a predetermined position with respect to the holder 32A. The flange member 36 is attached to the upper opening edge 34 of the holder 32A by an attachment member such as a screw 36A.

In the holder 32A, the mixing liquid tank 38 into which the irradiation horn 33D is inserted and the mixed liquid is supplied is arranged in the center, and the cooling liquid tank 40 through which the cooling liquid flows so as to surround the outer periphery thereof is arranged around the mixed liquid tank 38. The mixing liquid tank 38 has a cylindrical shape and is opened to the outside through the upper opening edge 34.

An inlet portion (intake port) 38A is provided in the center of the bottom surface of the mixed liquid tank 38, and the mixed liquid supply pipe 42A is connected to the inlet portion (intake port) 38A. An outlet portion (outlet port) 38B is provided on the upper outer portion of the mixing liquid tank 38, and the mixing liquid discharge pipe 42B is connected to the outlet portion (outlet) 38B. That is, the mixed liquid flows in from the center of the bottom of the mixed liquid tank 38 and is discharged from the upper outer side.

On the other hand, an inlet portion 40A is provided on the lower outer portion of the coolant tank 40, and the coolant supply pipe 44A is connected to the inlet portion 40A. On the other hand, in the upper outer portion of the coolant tank 40, for example, an outlet portion 40B is provided on the side substantially opposite to the inlet portion 40A with the mixing liquid tank 38B interposed therebetween, and the coolant discharge pipe 44B is connected. The cooling liquid suppresses the temperature rise of the mixed liquid in the holder 32A due to ultrasonic vibration.

As shown in FIG. 4, the lower end surface 33E of the cylindrical irradiation horn 33D is arranged at a predetermined distance from the bottom surface of the mixing liquid tank 38. As a result, flow paths at regular intervals are formed between the mixed liquid tank 38 and the irradiation horn 33D.

On the other hand, in FIG. 5, the positions of the inner peripheral surface of the inlet portion 38A of the mixed liquid tank 38, the outer peripheral surface of the irradiation horn 33D, the outer peripheral wall of the mixed liquid tank 38, and the outer peripheral wall of the coolant tank 40 are drawn. As shown in FIG. 5, in the present embodiment, the inner peripheral surface of the inlet portion 38A of the mixed liquid tank 38, the outer peripheral surface of the irradiation horn 33D, the outer peripheral wall of the mixed liquid tank 38, and the coolant tank 40 are substantially concentric. It is arranged, and flow paths at regular intervals are formed between the outer peripheral surface of the irradiation horn 33D and the inner peripheral surface of the mixing liquid tank 38.

The inner diameter of the circular opening of the inlet portion 38A is smaller than the outer diameter of the irradiation horn 33D, and the mixed liquid flowing into the mixing liquid tank 38 from the inlet portion 38A is substantially vertically upward toward the center of the bottom surface of the irradiation horn 33D. It hits the lower end surface 33E of the irradiation horn 33D and changes the direction of the flow radially in a substantially horizontal direction. The mixed liquid flows radially outward along the flow path formed between the bottom surface of the mixed liquid tank 38 and the irradiation horn 33D. In the same path, the mixed liquid moves along the lower end surface 33E constituting the vibration surface of the irradiation horn 33D. Therefore, the powder of the mixed liquid is efficiently and uniformly dispersed by the ultrasonic cavitation generated by the lower end surface 33E of the irradiation horn 33D.

When the mixed liquid flowing radially reaches the vicinity of the inner peripheral surface of the mixing liquid tank 38, it hits the inner peripheral surface and the flow is changed upward. As a result, the mixed liquid rises along the flow path between the inner peripheral surface of the mixed liquid tank 38 and the outer peripheral surface of the irradiation horn 33D, and is discharged from the outlet portion 38B.

On the other hand, the coolant flowing into the coolant tank 40 from the inlet portion 40A flows along the annular flow path formed between the outer peripheral surface of the mixing liquid tank 38 and the inner peripheral surface of the coolant tank 40. It is discharged from the outlet portion 40B on the opposite side. That is, heat exchange is performed between the mixed liquid flowing in the mixed liquid tank 38 and the cooling liquid flowing in the cooling liquid tank 40 through the side wall of the mixed liquid tank 38, and the mixed liquid is cooled.

Next, with reference to the graph of FIG. 6, a method of operating the rotor stator type disperser and the ultrasonic homogenizer in the powder dispersion processing using the solid-liquid dispersion system 10 of the present embodiment will be described. The horizontal axis of FIG. 6 is time, and the vertical axis is the viscosity of the mixture.

At the start of the dispersion treatment, the liquid is charged into the tank 12. Further, the pump 16, the rotor stator type disperser 18, and the cooler 22 are driven, while the first and second ultrasonic homogenizer units 14 and 20 are maintained in a stopped state. By driving the pump 16, the liquid is circulated in the solid-liquid dispersion system 10 through the circulation passage 25.

After that, when the powder charging is started through the rotor stator type disperser 18, the viscosity value measured by the viscometer 31 rapidly increases from the viscosity V0 of the liquid itself until the powder charging is completed, and reaches the maximum. The viscosity reaches V1. When the charging of the powder is stopped and the dispersion of the powder progresses, the size of the lump of the charged powder becomes smaller, and the viscosity measured by the viscometer 31 gradually and monotonically decreases.

In the present embodiment, only the rotor stator type disperser 18 is driven and the first and second ultrasonic homogenizer units 14 and 20 are stopped from the start of the dispersion treatment until the value of the viscometer 31 drops to a predetermined viscosity V2. Is maintained (first step A1). When the viscosity becomes V2 or less, the driving of the first and second ultrasonic homogenizer units 14 and 20 is started, and the dispersion processing is performed on the rotor stator type disperser 18 and the first and second ultrasonic homogenizer units 14 and 20. Is executed by (second step 2).

In the present embodiment, when the viscosity further decreases to a predetermined viscosity V3, the driving of the rotor stator type disperser 18 is stopped, and the dispersion processing is executed only by the first and second ultrasonic homogenizer units 14 and 20 (third). Step A3). When the viscosity drops to the desired (target) viscosity V4, all the drives of the rotor stator type disperser 18, the first and second ultrasonic homogenizer units 14 and 20 are stopped, and the dispersion process is completed.

In the present embodiment, it is also possible to change the amplitude of the ultrasonic homogenizer 32 and the number of ultrasonic homogenizers 32 to be driven between the second step A2 and the third step A3 by the control device 34. For example, in the second step A2, eight ultrasonic homogenizers 32 provided in the first and second ultrasonic homogenizer units 14 and 20 are driven with an amplitude of 40 μm, and in the third step A3, the first and second ultrasonic homogenizers are driven. The eight ultrasonic homogenizers 32 provided in the units 14 and 20 may be driven with an amplitude of 15 μm. Further, in the second step A2, eight ultrasonic homogenizers 32 provided in the first and second ultrasonic homogenizer units 14 and 20 are driven with an amplitude of 40 μm, and in the third step A3, the first ultrasonic homogenizer unit 14 is driven. Two of the four ultrasonic homogenizers 32 provided are driven with an amplitude of 40 μm, the driving of the two ultrasonic homogenizers 32 is stopped, and the four ultrasonic homogenizers possessed by the second ultrasonic homogenizer unit 20 are stopped. Two of the 32 ultrasonic homogenizers 32 may be driven with an amplitude of 40 μm, and the driving of the two ultrasonic homogenizers 32 may be stopped.

As described above, according to the solid-liquid dispersion system of the present embodiment, different types of dispersers (homogenizers) are provided in the circulation path of the mixed liquid, and these drives are switched according to the viscosity of the mixed liquid. Effectively disperse powders and produce high-quality suspensions for various combinations of powders and liquids without causing deterioration of quality due to powder destruction or insufficient dispersion. Can be done.

Further, in the configuration of the ultrasonic homogenizer of the present embodiment, all the mixed liquid flowing through the holder moves along the vicinity of the vibrating surface of the irradiation horn, so that the powder in the mixed liquid efficiently becomes one by ultrasonic cavitation. It is possible to produce a suspension in which the powder is dispersed more uniformly.

Next, a modified example of the solid-liquid dispersion system 10 of the present embodiment will be described with reference to FIG. 7. In the ultrasonic homogenizer units 14 and 20 of the embodiment, a plurality of ultrasonic homogenizers 32 are connected in parallel, but in the ultrasonic homogenizer units 14 and 20 of the modified example, a plurality of (4 units) ultrasonic homogenizers 32 are connected in series. Is connected to. That is, the mixed liquid discharge pipe 42B of each ultrasonic homogenizer 32 except the ultrasonic homogenizer 32 in the last stage is used as the mixed liquid supply pipe 42A of the ultrasonic homogenizer 32 in the next stage. The same effect as that of the embodiment can be obtained in the solid-liquid dispersion system of the modified example.

The amplitude and frequency of each ultrasonic homogenizer may be adjusted individually according to the conditions, and the selection and combination of drive / stop of each homogenizer including the rotor stator type disperser are also limited to this embodiment. It's not something.

In the present embodiment, the configurations of the first and second ultrasonic homogenizer units are the same, but they may have different configurations. For example, the number of ultrasonic homogenizers constituting the first and second ultrasonic homogenizer units may be different, and the ultrasonic homogenizers may be connected in parallel in one unit and in series in the other unit. Further, parallel connection and series connection may be mixed in one unit.

In the solid-liquid dispersion system of the present embodiment, one rotor stator type disperser and a pair of ultrasonic homogenizer units are used in combination, but if switching drive can be performed according to the state of the mixed liquid, each device can be used. The number of units and the combination of arrangements can be changed.

10 Solid-liquid dispersion system 14 1st ultrasonic homogenizer unit 18 Rotor stator type disperser 18A Rotor 18B stator 18C Inlet part (supply port)
18D dispersion room 18E outlet part (exhaust port)
20 Second ultrasonic homogenizer unit 25 Circulation passage 31 Viscometer (viscosity detection means)
32 Ultrasonic homogenizer 32A holder 33D Irradiation horn 34 Control device (control means)
38A inlet (intake)
38B outlet part (outlet)

Claims (4)

A solid-liquid dispersion system that mixes and disperses powder and liquid.
A disperser having a supply port for supplying a mixed liquid of powder and a liquid, a dispersion chamber for mixing and dispersing the supplied mixed liquid with a rotor and a stator, and a discharge port for discharging the mixed and dispersed mixed liquid. When,
A circulation passage that communicates the discharge port and the supply port and circulates the mixed liquid discharged from the dispersion device to the supply port.
An ultrasonic homogenizer provided in the circulation passage and
A viscosity detecting means provided in the circulation passage to detect the viscosity of the mixture,
The disperser and the control means for controlling the operation of the ultrasonic homogenizer are provided.
The control means is characterized in that only the disperser, the disperser, the ultrasonic homogenizer, and only the ultrasonic homogenizer can be selectively operated according to the value of the viscosity detected from the viscosity detecting means. Liquid mixing and dispersion system. The solid-liquid mixing / dispersing system according to claim 1, wherein a plurality of the ultrasonic homogenizers are provided and the operation of each ultrasonic homogenizer can be controlled. The solid-liquid mixing / dispersing system according to claim 2, wherein the ultrasonic homogenizers are provided in parallel. The claim is that the ultrasonic homogenizer includes a holder that covers an ultrasonic irradiation horn, and the holder is formed with an intake port for a mixed solution at the lower side and an outlet for a mixture at the side. The solid-liquid mixture / dispersion system according to any one of 1 to 3.

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