JP6862880B2 - Stirrer and control device - Google Patents

Description

The present invention relates to a stirrer and a control device that controls the stirrer.

When producing a slurry containing metal powder (hereinafter also referred to as "object to be agitated"), since the metal powder is heavy with respect to the solvent, a stirring device such as a propeller is attached to the lower part of the container and is always operated. The slurry in the container is homogenized (see, for example, Patent Document 1). In the manufacturing process for handling these slurries, there are various situations such as sending the slurry from the inside of the container to the next process by a pump or the like, or storing the slurry in a certain container. Naturally, the amount of slurry in the container changes from time to time, and in some cases, the characteristics of the slurry may also change.

The stirring device has a propeller or the like attached near the bottom of the container and is constantly rotated. There is no problem if the amount of slurry in the container is enough to cover the propeller, but as the amount of slurry decreases, the liquid level of the slurry becomes greatly wavy, or the liquid level drops due to centrifugal force and the slurry scatters. I have something to do. In addition, a bubbling phenomenon may occur depending on the type of slurry. In the past, it was assumed that waviness and scattering would occur to some extent, and measures were taken to prevent scattering with covers and covers, but there were problems such as cleaning scattered and adhering objects and the inability to install peepholes. It was.

Therefore, conventionally, in order to suppress the scattering of the slurry during stirring, a method of measuring the position of the liquid level using a liquid level sensor or the like and controlling the rotation speed of the stirring device according to the amount of the slurry has been adopted. There is.

JP-A-2015-42384

However, in the case of the method of controlling the rotation speed of the stirring device based on the liquid level height of the above-mentioned slurry, there is no problem when it is used for the same type of slurry, but when the type of slurry is switched or during the process, the slurry is used. When used for slurries with different characteristics, such as when the characteristics of the slurry change, the relationship between the liquid level height and the degree of slurry scattering changes, so there is a problem that the scattering of the slurry due to stirring cannot be sufficiently suppressed. is there.

For example, in the case of a stirrer installed in a receiving / paying container used in a process of refining metal powder or the like using a high-pressure homogenizer, the slurry in the receiving / paying container is crushed by the homogenizer and becomes smaller, and the viscosity changes. .. Usually, pulverization with a homogenizer is often repeated about 5 to 30 times. Therefore, the slurry in the receiving and paying container has a difference in particle size between the beginning and the end, and the characteristics of the slurry also change. When the characteristics of the slurry change in this way, in the above-mentioned rotation speed control based on the height of the liquid level, the liquid level position for switching the rotation speed of the stirring device according to the change in the characteristics of the slurry must be reset each time. There wasn't. The same was true when the characteristics of the slurry were changed by adding an additional solvent or the like.

Therefore, the present invention provides a stirring device capable of stably suppressing scattering of the material to be agitated during stirring and a control device thereof even when the type of the material to be agitated is changed or the characteristics of the material to be agitated are changed in the process. Is required.

The stirring device according to one aspect of the embodiment of the present invention includes a container, a stirring unit for stirring the material to be agitated in the container, a liquid level measuring unit for measuring the liquid level position of the material to be agitated, and the liquid. the basis of the liquid surface position information measured by the surface measurement unit, the calculating the rippling intensity indicates the magnitude of the waves generated in the liquid level of the stirring thereof, rippling of the object to be stirred was based on the ruffling intensity A control device for controlling the number of rotations of the stirring unit so as to suppress the stirring unit is provided.

Similarly, the control device according to one aspect of the embodiment of the present invention includes a container, a stirring unit that stirs the agitated object in the container, and a liquid level measuring unit that measures the liquid level position of the agitated object. , a controller for controlling the operation of the stirring device comprising a, based on the information of the liquid surface position to be measured by the liquid level measuring section, indicating the size of the waves generated in the liquid surface of the object to be stirred was It has a calculation unit for calculating the rippling intensity and a control unit for controlling the rotation speed of the stirring unit so as to suppress the rippling of the agitated object based on the rippling intensity.

According to the present disclosure, a stirring device capable of stably suppressing scattering of the material to be agitated during stirring and its control even when the type of the material to be agitated is changed or the characteristics of the material to be agitated are changed in the process. Equipment can be provided.

The figure which shows the schematic structure of the stirring apparatus which concerns on 1st Embodiment. The flowchart of the rotation speed control of the stirring part carried out by the stirring apparatus which concerns on 1st Embodiment. The figure which shows an example of the calculation method of the undulation amplitude of the agitated object. The flowchart of the rotation speed control of the stirring part carried out by the stirring apparatus which concerns on 2nd Embodiment. The figure which shows an example of the calculation method of the rippling intensity of the agitated object. The figure which shows the test result of an Example.

Hereinafter, embodiments will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as much as possible in each drawing, and duplicate description is omitted.

[First Embodiment]
The first embodiment will be described with reference to FIGS. 1 to 3. First, with reference to FIG. 1, a schematic configuration of the stirring device 1 according to the first embodiment will be described. The stirring device 1 shown in FIG. 1 is a device for stirring an object to be agitated (slurry) such as a liquid raw material. The stirring device 1 is applied, for example, as a receiving / paying container used in a step of refining metal powder or the like using a homogenizer. Here, the homogenizer is a device that pressurizes a raw material to a high pressure or an ultra-high pressure and crushes, disperses, etc. by utilizing the shearing force when passing through the orifice. In the following, the upper and lower parts of FIG. 1 will be described as upper and lower parts of the device, respectively.

As shown in FIG. 1, the stirring device 1 measures the positions of the container 2, the stirring unit 3 for stirring the agitated object S in the container, and the liquid level of the agitated object S in the container. It includes a measuring unit 4 and a control device 5 that controls the rotation speed of the stirring unit 3 from the detected value of the liquid level measuring unit 4.

The container 2 is a container that holds the object to be agitated S. The agitated material S is not particularly limited, but is a slurry obtained by mixing a metal powder, a ceramic powder, and a solvent. In particular, for those having a large specific gravity with respect to the solvent such as metal powder, constant stirring is required. The container 2 is provided with a discharge port 2A for discharging the agitated object S and a supply port 2B for supplying the agitated object S. For example, as shown in FIG. 1, the discharge port 2A is provided at the lower part of the container 2, and the supply port 2B is provided at the upper part of the container 2 (preferably above the liquid level of the agitated object S). In the container 2, the agitated material S is supplied from the supply port 2B, and after being agitated, the agitated material S is discharged from the discharge port 2A. Therefore, the amount of the agitated material S in the container 2 changes. The number of supply ports 2B or discharge ports 2A of the container 2 may be plural. The container 2 may be used as a container for temporarily storing the object to be agitated S during the process, or may be used as a storage container for repeating the same process a plurality of times.

Further, a lid 2C is attached to the upper part of the container 2 so that the agitated object S does not scatter. The lid 2C is provided with, for example, a glass transparent window 2D.

The stirring unit 3 is a mechanism for stirring the object to be agitated S in the container 2. A stirring blade 3A is installed at the tip of the stirring unit 3. The stirring blade 3A directly contacts the agitated object S in the container 2 and agitates the agitated object S by rotation. The shape of the stirring blade 3A is not particularly limited, but a propeller shape, a frame shape, or the like is used. The stirring blade 3A is rotationally driven by a drive unit 3B including a drive source such as a motor and a drive shaft that transmits power output from the drive source. Further, the stirring blade 3A is arranged near the lower part of the container 2. This is to enable stirring even if the amount of the object to be agitated S in the container is small.

The liquid level measuring unit 4 detects the position of the liquid level of the agitated object S contained in the container 2. The liquid level measuring unit 4 is an optical sensor in this embodiment. If the liquid level measuring unit 4 is an optical sensor, it can be installed above the liquid level and does not need to be in direct contact with the agitated object S, so that the measurement is affected by the flow of the agitated object or the like. Less is. In addition, the optical sensor can perform a plurality of measurements in a short time, and can perform highly accurate measurements. In the present embodiment, the liquid level measuring unit 4 is installed above the outside of the container 2 and directly above the window 2D of the lid 2C of the container 2, and is covered in the container 2 via the transparent window 2D. It is installed so that the liquid level of the agitated material S can be measured.

The liquid level measuring unit 4 may use a sensor other than the optical sensor as long as the height position of the liquid level can be measured. For example, another sensor such as an ultrasonic sensor that detects the distance to the liquid surface by using a wave other than light may be used, or a float switch, a water pressure sensor, or the like that directly contacts the agitated object S may be used.

The control device 5 controls the operation of the stirring unit 3. In particular, in the present embodiment, the control device 5 calculates the rippling intensity of the liquid level of the agitated object S based on the information of the liquid level position of the agitated object S measured by the liquid level measuring unit 4, and obtains the rippling intensity. Based on this, the rotation speed of the stirring unit 3 is controlled so as to suppress the waviness of the agitated object S.

The control device 5 has a calculation unit 5A for calculating the rippling intensity and a control unit 5B for controlling the stirring unit 3. More specifically, the control device 5 reduces the rotation speed of the agitated unit 3 as the rippling intensity of the agitated object S calculated by the calculation unit 5A increases, whereby the rippling of the agitated object S can be suppressed. It is configured. The control unit 5B can switch, for example, the rotation speed of the stirring unit 3 to a plurality of set speeds. In the first embodiment, the rippling amplitude A of the agitated object S is used as specific information indicating the “wavy intensity”.

The control device 5 is physically a computer having a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. All or part of each function of the arithmetic unit 5A and the control unit 5B of the control device 5 loads the application program held in the ROM into the RAM and executes it in the CPU to read and write data in the RAM or ROM. It is realized by doing.

Next, the operation of the stirring device 1 according to the first embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart of the rotation speed control of the stirring unit 3 implemented by the stirring device 1 according to the first embodiment. FIG. 3 is a diagram showing an example of a method for calculating the rippling amplitude A of the agitated object S. The flowchart shown in FIG. 2 is executed periodically, for example, at predetermined time intervals. Hereinafter, description will be given according to the procedure of the flowchart of FIG.

In step S11, the position of the liquid level of the agitated object S in the container 2 is measured by the liquid level measuring unit 4. As described above, in the present embodiment, the liquid level measuring unit 4 is an optical sensor installed above the container 2. The liquid level measuring unit 4 measures the liquid level position a plurality of times within a predetermined period, for example, 10 times per second. When the process of step S11 is completed, the process proceeds to step S12.

In step S12, the calculation unit 5A of the control device 5 calculates the rippling amplitude A of the liquid level of the agitated object S in the container 2 using the plurality of liquid level position data measured in step S11. As shown in FIG. 3, for example, the calculation unit 5A uses the difference between the maximum value Xmax and the minimum value Xmin as the rippling amplitude A among the liquid level position data of a plurality of times in a predetermined period measured by the liquid level measuring unit 4. Can be calculated. Alternatively, the calculation unit 5A can also calculate the degree of variation (for example, dispersion value) of the liquid level position data a plurality of times as the rippling amplitude A. When the process of step S12 is completed, the process proceeds to step S13.

In step S13, the control unit 5B of the control device 5 determines whether or not the rippling amplitude A of the agitated object S calculated in step S12 exceeds a predetermined threshold value.

When it is determined in step S13 that the amplitude A is larger than the threshold value, the rippling intensity exceeds the permissible range, so that the rotation speed of the stirring unit 3 is lowered by one step in step S14, and the rippling is suppressed. Will be done. If there is no setting on the lower speed side than the current rotation speed and the current rotation speed is the slowest, the operation of the stirring unit 3 may be stopped. When the process of step S14 is completed, this control flow ends.

On the other hand, when it is determined in step S13 that the amplitude A is equal to or less than the threshold value, the current rotation speed of the stirring unit 3 is maintained and the control flow is terminated.

If the rotation speed control of the stirring unit 3 is not a multi-step switching type as described above but is performed steplessly using an inverter or the like, rippling is performed instead of steps S13 and S14 described above. The rotation speed may be continuously adjusted according to the magnitude of the amplitude A of the above. In this case, for example, as the amplitude A increases, the rotation speed is controlled to decrease.

Here, when the liquid level position of the agitated object S in the container 2 is reduced to the extent that the agitating blade 3A of the agitating unit 3 is exposed from the liquid surface, the agitated object S even if the rotation speed of the agitating unit 3 is reduced. May jump. In order to avoid such a situation, the control device 5 further stops the rotation of stirring at a position where the stirring object S does not expose the stirring blade 3A of the stirring unit 3 in addition to the processing described in the flowchart of FIG. You can also add controls. For example, by using the average value of the liquid level positions of the measured values of the liquid level measuring unit 4 for a certain period of time, the liquid level position can be calculated even if the object S to be measured has waviness. By using this average value, ON-OFF of stirring in the stirring unit is controlled. For example, when the average value falls below a predetermined value, it is determined that the object to be agitated S has decreased until the stirring blade 3A is exposed, and the stirring is turned off (stirring unit 3 stopped). The position of the object to be agitated S to be turned off can be appropriately set depending on the shape of the agitating blade 3A and the like.

Further, even if the minimum rotation speed of the stirring unit 3 that can be lowered by the control device 5 is changed according to the height of the liquid level position of the agitated object S in the container 2, that is, the amount of the agitated object S. Good. For example, when the amount of the agitated object S is large, the agitation performance can be ensured by setting the minimum rotation speed to be relatively large.

In the flowchart of FIG. 2, only the configuration in which the rotation speed of the stirring unit 3 is lowered by one step when the rippling amplitude A of the agitated object S exceeds the threshold value is illustrated, but in addition to this, the amplitude A is minute. When the state, that is, the state in which the waviness is small continues, the rotation speed of the stirring unit 3 may be increased by one step to switch to a high speed.

Next, the effect of the stirring device 1 according to the first embodiment will be described.

First, the conventional control method of the stirring device 1 shown in FIG. 1 and its problems will be described. In the stirring device 1 of FIG. 1, since the agitated material S in the container 2 is discharged from the discharge port 2A and the agitated material S is injected into the container 2 from the supply port 2B, the agitated material in the container 2 is injected. The liquid level position of S fluctuates. Generally, as the amount of the agitated object S in the container 2 decreases and the liquid level of the agitated object S decreases and becomes closer to the agitating blade 3A of the agitating section 3, the rippling of the liquid level increases. Conventionally, in order to suppress this undulation, the control device 5 has controlled in the direction of lowering the rotation speed of the stirring blade 3A of the stirring unit 3 as the liquid level of the agitated object S drops.

Here, when the stirring device 1 is applied to a receiving / paying container for a step of micronizing metal powder or the like using a homogenizer, as described above, crushing with the homogenizer is repeated about 5 to 30 times in the container 2. The particle size of the slurry (object to be agitated S) of No. 1 changes at the beginning and the end of the process, and the characteristics of the slurry also change. When the characteristics of the slurry change, the viscosity of the slurry also changes, so that the waviness behavior is different even if the positional relationship between the stirring blade 3A and the liquid level of the agitated object S is the same. For example, as the process progresses and the viscosity of the slurry decreases, the waviness tends to increase, and conversely, when the viscosity increases, the waviness tends to decrease.

Further, in addition to the change in the characteristics of the same slurry during the process, there is a similar tendency when the type of the object to be agitated S supplied to the container 2 is changed. For example, there are a plurality of supply ports 2B of the container 2, and another type of agitated material S having a different viscosity is supplied to the container 2, or the agitated material S discharged from the discharge port 2A is processed and reconstituted from the supply port 2B. When it is supplied to No. 2 and the characteristics of the agitated object S are changed, the magnitude of the waviness may change even if the liquid level is the same.

In this way, the tendency of the agitated object S to undulate differs depending on the characteristics and type of the agitated object S in the container 2, and the relationship between the liquid level and the degree of scattering of the agitated object S due to agitation changes. Therefore, in the conventional control of the rotation speed of the stirring unit 3 based on the liquid level, there is a case where the scattering of the agitated object S during stirring cannot be sufficiently suppressed.

On the other hand, the stirring device 1 of the first embodiment includes the container 2, the stirring unit 3 for stirring the agitated object S in the container 2, and the liquid level measuring unit 4 for measuring the liquid level position of the agitated object S. And, the rippling intensity of the liquid level of the agitated object S is calculated based on the information of the liquid level position measured by the liquid level measuring unit 4, and the agitating unit 3 suppresses the rippling of the agitated object S based on the rippling intensity. A control device 5 for controlling the number of rotations is provided.

Similarly, the control device 5 according to the first embodiment includes a container 2, a stirring unit 3 for stirring the agitated object S in the container 2, and a liquid level measuring unit 4 for measuring the liquid level position of the agitated object S. It controls the operation of the stirring device 1 provided with the above. The control device 5 has a calculation unit 5A that calculates the rippling intensity of the liquid level of the agitated object S based on the information of the liquid level position measured by the liquid level measuring unit 4, and the rippling of the agitated object S based on the rippling intensity. It has a control unit 5B that controls the rotation speed of the stirring unit 3 so as to suppress it.

With these configurations, the rotation speed of the stirring unit 3 is controlled so as to suppress the rippling based on the rippling intensity due to the stirring of the agitated object S in the container 2, so that the characteristics of the agitated object S in the container 2 and the characteristics of the agitated object S are controlled. Even if the tendency of the rippling of the agitated object S fluctuates due to a change in the type or the like, the rotation speed of the stirring unit 3 can be appropriately set, and the rippling of the agitated object S during agitation can be reliably suppressed. Therefore, the stirring device 1 of the first embodiment and the control device 5 that controls the operation of the stirring device 1 respond to changes in the type of the agitated object S and changes in the characteristics of the agitated object S in the process. However, the scattering of the object to be agitated S during agitation can be stably suppressed. Further, if the waviness of the agitated object S can be suppressed, the liquid level state of the agitated object S becomes stable, so that the liquid level measurement becomes easy and accurate.

Further, in the stirring device 1 of the first embodiment, the control device 5 reduces the rotation speed of the stirring unit 3 as the rippling intensity increases. With this configuration, the rippling of the agitated object S is weakened by reducing the rotation speed of the agitating unit 3, so that the rippling of the agitated object S can be suppressed more reliably.

Further, in the stirring device 1 of the first embodiment, the “wavy intensity” of the agitated object S used as a determination criterion for the rotation speed control is the rippling amplitude A of the agitated object S. Since the amplitude A is closely related to the rippling intensity, the rippling intensity can be accurately grasped by using the amplitude A, and the rotation speed control of the stirring unit 3 can be performed with high accuracy.

Further, in the stirring device 1 of the first embodiment, the control device 5 calculates the difference between the maximum value Xmax and the minimum value Xmin from the information of the liquid level position measured a plurality of times in a predetermined period by the liquid level measuring unit 4. , The difference is used as the rippling amplitude A of the agitated object S. With this configuration, the time transition of the calculated amplitude A can be smoothed as compared with the case where the rippling amplitude is calculated as an instantaneous value, such as the difference between the current value and the previous value of the liquid level position, and is based on this amplitude A. The system for controlling the rotation speed of the stirring unit 3 can be improved.

Further, in the stirring device 1 of the first embodiment, the liquid level measuring unit 4 is an optical sensor that measures the liquid level position from above the liquid level of the agitated object S. With this configuration, it is not necessary to bring the liquid level measuring unit 4 into direct contact with the agitated object S, and it is possible to avoid being affected by the flow of the agitated object S or the like in the measurement. Further, since the optical sensor can perform a plurality of measurements in a short time, the number of measurement data per unit time can be increased, and high-precision measurement becomes possible.

Further, in the stirring device 1 of the first embodiment, the stirring unit 3 has a stirring blade 3A for stirring the object to be agitated S by rotation and a driving unit 3B for rotationally driving the stirring blade 3A. With this configuration, the object to be agitated S can be efficiently agitated in the container 2.

[Second Embodiment]
The second embodiment will be described with reference to FIGS. 4 and 5. In the second embodiment, the rotation speed control of the stirring unit 3 implemented by the control device 5 is different from that in the first embodiment.

In the second embodiment, the control device 5 implements the first control of reducing the rotation speed of the stirring unit 3 when the liquid level position of the agitated object S becomes lower than the threshold value, and further, the calculation unit 5A calculates. The larger the rippling intensity is, the second control is performed to increase the threshold value for the first control.

In the first control, for example, in the case where the control unit 5B can switch the rotation speed of the stirring unit 3 to a plurality of set speeds as in the first embodiment, the stirring is performed when the liquid level position becomes lower than the threshold value. The rotation speed of the part 3 is switched to the low speed side by one step. In the second control, as the rippling of the agitated object S becomes larger, this threshold value is increased to advance the timing of switching the rotation speed of the stirring unit 3 to a low speed, whereby the rippling can be quickly reduced.

FIG. 4 is a flowchart of the rotation speed control of the stirring unit 3 implemented by the stirring device 1 according to the second embodiment. FIG. 5 is a diagram showing an example of a method for calculating the rippling intensity R of the agitated object S. The flowchart shown in FIG. 4 is periodically executed, for example, at predetermined time intervals. As a premise of the flowchart of FIG. 4, the above-mentioned first control is being executed, and the flowchart of FIG. 4 is a specific process of the second control. Hereinafter, description will be given according to the procedure of the flowchart of FIG.

In step S21, the position of the liquid level of the agitated object S in the container 2 is measured a plurality of times in a predetermined period by the liquid level measuring unit 4. When the process of step S21 is completed, the process proceeds to step S22.

In step S22, the calculation unit 5A of the control device 5 averages the plurality of liquid level position data measured in step S21, and this average value is used as the liquid level position X of the agitated object S in the container 2. Calculated. The calculation unit 5A averages the data measured 10 times per second by, for example, the liquid level measurement unit 4, and calculates it as the current liquid level position X. When the process of step S22 is completed, the process proceeds to step S23.

In step S23, the maximum value Rmax or the minimum value is used by the calculation unit 5A using the deviation ΔX between the liquid level position X calculated in step S22 and the previous value of the liquid level position calculated in the previous control flow. Rmin is updated. When the deviation ΔX is a positive value, that is, when the liquid level position X is increased from the previous value, the calculation unit 5A compares the stored maximum value Rmax with the deviation ΔX, and the deviation ΔX is larger. When it is large, the maximum value Rmax is updated. Further, when the deviation ΔX is a negative value, that is, when the liquid level position X is decreasing with respect to the previous value, the calculation unit 5A compares the stored minimum value Rmin with the deviation ΔX, and the deviation ΔX. If is smaller, the minimum value Rmin is updated. When the process of step S23 is completed, the process proceeds to step S24.

In step S24, the calculation unit 5A calculates the rippling intensity R of the liquid level of the agitated object S in the container 2 using the maximum value Rmax and the minimum value Rmin updated in step S23. The calculation unit 5A calculates the rippling intensity R using, for example, the following equation (1).
R = | Rmax | + | Rmin | ... (1)

The rippling intensity R used in the second embodiment is, for example, as shown in FIG. 5, the maximum sway width in the liquid level increasing direction in which the generation timings are different in all the past time steps during the execution of the first control. In FIG. 5, it is the total value of the maximum value Rmax at time t1) and the maximum swing width in the liquid level decreasing direction (minimum value Rmin at time t2 in FIG. 5). The rippling intensity R used in the second embodiment can also be expressed as the degree of variation in the liquid level position of the agitated object S. When the process of step S24 is completed, the process proceeds to step S25.

In step S25, the control unit 5B of the control device 5 determines whether or not the liquid level position X of the agitated object S calculated in step S22 satisfies the condition of the following equation (2).
Liquid level position X <threshold value + R / 2 ... (2)
Here, the first term on the right side of the equation (2) is the threshold value of the first control, and the second term is the bulking amount of the threshold value based on the rippling intensity R of the agitated object S calculated in step S24. .. The larger the rippling intensity R, the larger the amount of raising of the threshold value of the first control, and the earlier the timing of switching the rotation speed of the stirring unit 3 to a low speed.

When it is determined in step S25 that the liquid level position X is smaller than the threshold value + R / 2, the rotation speed of the stirring unit 3 is lowered by one step in step S26, and rippling is suppressed. If there is no setting on the lower speed side than the current rotation speed and the current rotation speed is the slowest, the operation of the stirring unit 3 may be stopped. When the process of step S26 is completed, this control flow ends.

On the other hand, when the liquid level position X is determined to be the threshold value + R / 2 or more in step S25, the current rotation speed of the stirring unit 3 is maintained and the main control flow is terminated.

In the stirring device 1 according to the second embodiment, the control device 5 increases the raised amount of the threshold value of the first control represented by the equation (2) as the rippling intensity R of the object to be agitated S increases, and the stirring unit The timing for switching the rotation speed of 3 to a low speed can be accelerated, so that the undulation can be quickly reduced when the undulation of the agitated object S is large. That is, the second embodiment also has the same feature as the first embodiment that the rotation speed of the stirring unit 3 is controlled so as to suppress the rippling of the agitated object S based on the rippling intensity of the agitated object S. Similar to the first embodiment, it is possible to achieve the effect of stably suppressing the scattering of the agitated object S during agitation.

In addition, as the raising amount of the threshold value of the first control in step S25, instead of the rippling intensity R of the agitated object S calculated in step S24, the liquid level of the agitated object S used in the first embodiment. Rippling amplitude A can also be used. Further, the threshold value for switching the rotation speed of the stirring unit 3 may be a plurality of threshold values depending on the height of the liquid level position of the agitated object S.

Further, in the first control, contrary to the above description, when the liquid level position becomes higher than the threshold value, the rotation speed of the stirring unit 3 can be switched to the one-step high speed side. In this case, in the second control, as the rippling of the agitated object S becomes larger, this threshold value is increased to delay the timing of switching the rotation speed of the stirring unit 3 to a high speed, thereby causing the rippling before increasing the rotation speed. It is configured so that it can be reduced.

Hereinafter, examples using the present invention will be described. The stirring container 2 of this embodiment was made of metal and had a columnar shape having an inner diameter of 550 mm and a height of 600 mm. The container 2 is provided with a supply port 2B on the upper side surface and a discharge port 2A on the bottom surface. Further, a lid portion 2C is provided above the agitated object S so as not to scatter. The agitated material S used in this example was a mixture of Ni powder and a solvent. The viscosity of the agitated material S was 18.5 Pa · s.

The stirring blades 3A of the stirring unit 3 are two blades of a propeller type having a rotation diameter of 300 mm. A motor was used as the drive source of the drive unit 3B. The stirring blade 3A was installed at a position of about 100 mm from the bottom surface of the container 2 at the lower part inside the container 2.

An optical sensor was used for the liquid level measuring unit 4. The optical sensor was installed above the glass window 2D provided on the lid 2C of the container 2. The measurement by the liquid level measuring unit 4 was set to measure 10 times per second. Further, the rotation speed control of the motor of the stirring unit 3 is a three-stage switching type of 200 rpm (high speed), 150 rpm (medium speed), and 100 rpm (low speed).

Next, using the above device, the following test was performed to confirm the state of waviness of the agitated object S and the rotation speed of the agitating unit 3. The distance from the liquid level measuring unit 4 to the liquid level of the agitated object S inside the container 2 was measured 10 times per second. The maximum value and the minimum value of the 10 measured values were extracted, the difference between them was calculated (maximum value-minimum value), and this value was defined as the maximum height difference (mm) of the set of the measured values. .. That is, this maximum height difference is equivalent to the rippling amplitude A of the first embodiment. This measurement and calculation were performed a plurality of times under the conditions that the rotation speeds of the stirring unit 3 were 200, 150, and 100 rpm, respectively.

FIG. 6 is a diagram showing the test results of the examples. The horizontal axis of FIG. 6 indicates time, and the vertical axis indicates the maximum height difference of the waviness of the agitated object S. In FIG. 6, the maximum height difference of each set calculated for each of the 10 measured values of the liquid level measuring unit 4 in the above test is plotted. As shown in FIG. 6, when the rotation speed of the stirring unit 3 is high speed (200 rpm) and medium speed (150 rpm), the maximum height difference is large at about 100 mm and varies in a range of 20 mm to 120 mm. Is also big. That is, when the rotation speed is high speed and medium speed, the waviness of the agitated object S in the container 2 becomes strong.

On the other hand, when the rotation speed of the stirring unit 3 is low (100 rpm), the maximum height difference is within the range of 0 to 20 mm, and the variation is small and the value is stable and low. Therefore, according to this example, it was shown that even when the waviness of the agitated object S in the container 2 becomes large due to agitation, the rippling of the agitated object S can be surely suppressed by lowering the rotation speed of the agitation. In addition, there was no problem with the stirring performance.

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Those skilled in the art with appropriate design changes to these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the above-mentioned specific examples, its arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as there is no technical contradiction.

1 Stirring device 2 Container 3 Stirring unit 3A Stirring blade 3B Drive unit 4 Liquid level measurement unit 5 Control device 5A Calculation unit 5B Control unit S Stirred object R Rippling strength A Rippling amplitude

Claims (9)

With the container
A stirring unit that stirs the object to be agitated in the container, and a stirring unit.
A liquid level measuring unit for measuring the liquid level position of the object to be agitated, and a liquid level measuring unit.
Based on the liquid surface position information measured by the liquid level measuring unit, said calculating a rippling intensity indicates the magnitude of the waves generated in the liquid level of the stirring thereof, of the object to be stirred was based on the ruffling intensity A control device that controls the number of rotations of the stirring unit so as to suppress rippling, and
A stirrer equipped with. The control device reduces the rotation speed of the stirring unit as the rippling intensity increases.
The stirring device according to claim 1. In the rotation speed control of the stirring unit by the control device,
A threshold value is set so that the calculated rippling intensity increases as the intensity increases.
Wherein controlling said stirring section so as to reduce the rotational speed of the agitating portion when the liquid level position of the stirring object is lower than the threshold value,
The stirring device according to claim 1 or 2. The rippling intensity includes the rippling amplitude of the agitated object.
The stirring device according to any one of claims 1 to 3. The control device calculates the difference between the maximum value and the minimum value from the information on the liquid level position measured a plurality of times in a predetermined period by the liquid level measuring unit, and uses the difference as the amplitude of the waviness of the agitated object. Use,
The stirring device according to claim 4. The rippling intensity includes the degree of variation in the liquid level position of the agitated material.
The stirring device according to any one of claims 1 to 3. The liquid level measuring unit is an optical sensor that measures the liquid level position from above the liquid level of the object to be agitated.
The stirring device according to any one of claims 1 to 6. The stirring unit is
A stirring blade that agitates the object to be agitated by rotation,
A drive unit that rotationally drives the stirring blade and
Have,
The stirring device according to any one of claims 1 to 7. A control device for controlling the operation of a stirring device including a container, a stirring unit for stirring the material to be agitated in the container, and a liquid level measuring unit for measuring the liquid level position of the material to be agitated.
A calculation unit for calculating a waving intensity indicates the magnitude of the basis of the information of the liquid surface position to be measured by the liquid level measuring unit, generated on the liquid surface of the object to be stirred was waves,
A control unit that controls the rotation speed of the stirring unit so as to suppress the ripple of the object to be agitated based on the wave strength.
Control device with.

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