JP7006436B2 - Thickener device, rotation detection method of thickener rake - Google Patents

Description

The present invention relates to a thickener device, and relates to a thickener device capable of efficiently detecting the rotation of a rake (thickener rake) constituting the thickener device, and a method for detecting rotation of the thickener rake by the device.

A thickener device (also simply referred to as "thickener") is generally used as a means for concentrating and recovering solid particles suspended in a liquid by gravity. The structure of the thickener is, for example, a feed well for sedimenting and separating solid particles while the slurry and additives are supplied and flowing radially toward the peripheral wall of the tank, and a slow rotation of the scraping blade (rake). A type composed of a sedimentation concentration section that collects and concentrates the sedimented slurry in the center of the tank is used.

For example, Patent Document 1 includes a control device that detects a rake rotation torque and issues an operation command to an elevating means in an arbitrary torque range in order to maximize the density of the high-concentration slurry discharged from the thickener as much as possible. Thickener has been proposed.

In the thickener, the presence or absence of rotation of the rake greatly affects the slurry concentration, so it is important to know the presence or absence of the rotation. When the rotation of the rake is stopped and the slurry concentration (thickening) is deteriorated, it becomes difficult to stably supply the high-concentration slurry to the next step and thereafter, which greatly adversely affects the reaction efficiency of the next step and subsequent steps.

However, in the conventional thickener, especially the type of thickener in which the hydraulic drive gear and the rotation shaft of the rake are connected, it is not possible to know whether or not the rake is abnormally stopped unless the hydraulic unit for the drive gear shows an abnormality. ..

For example, even if one of a plurality of gear units is broken, the oil unit continues to operate, so that it is difficult to detect even if the rake stops due to gear damage. Further, even if the drive unit and the rotating shaft (rake shaft) are disengaged, the hydraulic unit continues to operate, so that detection becomes impossible.

In the conventional method, it is common to detect a hydraulic pressure abnormality due to an oil leak or an abnormal stop detection due to a decrease in the oil tank level. The first example described above features a hydraulic drive unit, but in the second example, in a system in which the motor and gears are directly connected and driven, the motor continues to rotate even if the drive unit and the rotating shaft are disconnected, so that the rake The problem is the deterioration of sickness due to the inability to detect a stop.

Further, in the rake rotation torque of Patent Document 1, although an alarm is issued by the torque lower limit, it is difficult to detect whether the device is abnormal because the rotation torque depends on the operating conditions.

Japanese Unexamined Patent Publication No. 9-271607 Japanese Unexamined Patent Publication No. 2013-154262

The present invention has been proposed in view of such circumstances, and efficiently detects the rotation of the thickener rake in a thickener device that separates a slurry containing a solid content into a supernatant liquid portion and a sedimentation concentration portion. The purpose is to be able to effectively suppress the influence on the next process due to deterioration of thickening and the like.

The present inventor has made extensive studies to solve the above-mentioned problems. As a result, in the relationship between the rake of the thickener and the level of the sedimentation aggregate layer formed in the thickener (bed level), it was found that the bed level increases or decreases at regular intervals when the rake is rotating. The invention was completed.

(1) The first invention of the present invention is a thickener device that performs sedimentation separation processing on a slurry to be processed, has a rake that rotates about a rotation axis, and rotates the rake to obtain the slurry. A thickener that forms an upper supernatant liquid portion and a lower sedimentation and concentration portion by sedimentation, and a measuring instrument provided so as to be located above the supernatant liquid portion of the thickener are used to settle and aggregate the sedimentation and concentration portion. A level measuring unit that measures the level of the layer over time in a non-contact manner and a rake rotation detecting unit that detects the rotation of the rake based on the level measurement of the sedimented aggregate layer by the level measuring unit are provided. The rake rotation detection unit is a thickener device that detects the rotation of the rake based on the presence or absence of detection of the maximum value and the minimum value within a predetermined set time in the measurement of the level of the settling aggregate layer by the level measurement unit. be.

(2) In the second aspect of the present invention, in the first invention, the rake rotation detecting unit has a maximum value and a minimum value within a predetermined set time in the measurement of the level of the settling aggregate layer by the level measuring unit. It is a thickener device that determines that the rake is rotating when a value is detected, and determines that the rake is stopped when the value is not detected.

(3) In the third invention of the present invention, in the first or second invention, the level measuring unit is provided so as to be located above the supernatant liquid portion in the thickener, and transmits ultrasonic waves. The ultrasonic transducer that receives the reflected wave at the interface between the liquid level of the supernatant liquid portion and the sedimented aggregate layer of the sedimentation concentration portion measures the time from the transmission of the ultrasonic wave to the reception of the reflected wave of the ultrasonic wave. It is a thickener device that calculates the distance to the interface based on the time.

(4) A fourth aspect of the present invention is a method for detecting rotation of a rake in a sickner device, wherein the liquid level of the upper supernatant liquid portion formed by the rotation of the rake provided in the sickner device and the lower part settling. By irradiating the interface of the concentrated part with the sedimented concentrated layer with ultrasonic waves, the level of the precipitated concentrated layer is measured, and the maximum value and the minimum value at the measured level within a predetermined set time are measured. This is a thickener rake rotation detection method that detects the rotation of the rake depending on the presence or absence of detection.

(5) In the fifth aspect of the present invention, in the fourth invention, the rake is rotated when a maximum value and a minimum value are detected at the measured level within a predetermined set time. This is a rotation detection method for the thickener rake, in which the rake is determined to be stopped if the rake is not detected.

According to the present invention, the presence or absence of rotation of the thickener rake can be efficiently detected, and the influence on the next process due to deterioration of sickening or the like can be effectively suppressed.

It is a schematic diagram which shows an example of the structure of a thickener device. It is a graph which shows an example of the transition of the level measurement value of the sedimentation aggregate layer, which is displayed on the screen by the monitoring part in the rake rotation detection part.

Hereinafter, a specific embodiment of the present invention (hereinafter, “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention.

≪1. Thickener device ≫
The thickener device according to the present embodiment is a device that performs sedimentation separation treatment on the slurry to be treated. FIG. 1 is a schematic diagram showing an example of the configuration of a thickener device.

As shown in FIG. 1, the thickener device 1 has a rake 11 and causes the slurry to settle by the rotation of the rake 11 to form a supernatant liquid portion in the upper part and a sedimentation concentration part in the lower part, and a settling agent 10. It includes a level measuring unit 13 that measures the level of the aggregate layer in a non-contact manner, and a rake rotation detecting unit 14 that detects the rotation of the rake 11 based on the level measurement by the level measuring unit 13.

Here, the thickener device 1 according to the present embodiment is not particularly limited, but is used, for example, in a process for producing a slurry of nickel oxide ore to be subjected to a leaching process using sulfuric acid in a hydrometallurgical process for nickel oxide ore. Can be done. Further, it can be used for a solid-liquid separation treatment for a leachate slurry containing a leachate and a leachate residue obtained by the leachate treatment with sulfuric acid. It should be noted that these are merely examples, and can be suitably used for other slurries.

[Thickener]
The thickener 10 includes a thickener body 10A including a cylindrical outer frame 10a and a conical bottom portion 10b gradually lowered toward the center. The thickener main body 10A is provided with a slurry recovery port 10c in the center of the conical bottom portion 10b for discharging and recovering a slurry having a desired concentration from the thickener main body 10A.

Inside the thickener 10, a rake (also referred to as "thickener rake") 11 is arranged along the inner surface of the conical bottom portion 10b. The rake 11 is composed of a rotating shaft 11a and a plurality of blades 11b provided at the tip of the rotating shaft 11a, and the blades 11b rotate about the rotating shaft 11a. By rotating the blade 11b, the rake 11 mixes the slurry with an additive such as a flocculant, and promotes sedimentation and concentration of the slurry in the sedimentation and concentration section formed in the thickener body 10A.

Further, inside the thickener 10, a cylindrical feed well 12 centered on the rotation shaft 11a of the rake 11 is provided so as to be located above the supernatant liquid portion formed in the thickener main body 10A, and the thickener 10 is provided. It is fixed to the upper lid 10d. A slurry supply pipe 12a for feeding a slurry to be subjected to sedimentation concentration treatment and an additive supply pipe 12b for feeding an additive such as a flocculant are connected to the feed well 12 at an upper position thereof. .. Further, a dispersion cone 12c is provided at a lower position of the feed well 12 to discharge the slurry from the feed well 12 and charge the slurry into the thickener main body 10A.

In such a thickener 10, the slurry to be subjected to the sedimentation concentration treatment and the additive such as a flocculant are charged into the feed well 12 and mixed, and are supplied from the feed well 12 into the thickener main body 10A. .. Then, the slurry supplied into the thickener main body 10A is mixed with a flocculant or the like and settles and aggregates to form an upper supernatant liquid portion and a lower sedimentation and concentration portion. The rake 11 provided inside the thickener 10 is slowly rotated by the drive of a drive unit (not shown) connected to the rotation shaft 11a, thereby promoting sedimentation and concentration of the slurry in the sedimentation and concentration unit. Ensure a uniform deposition state. The layer mainly composed of solid content formed in the sedimentation and concentration portion, that is, the layer of the slurry that has been sedimented and concentrated is referred to as a "precipitation and concentration layer".

[Level measurement unit]
The level measuring unit 13 is a sedimentation aggregate layer (sedimentation enrichment) of the sedimentation concentration portion formed below the supernatant liquid portion by a measuring instrument provided so as to be located above the supernatant liquid portion formed in the thickener 10. The level (bed level) of the slurry layer) is measured over time in a non-contact manner.

Here, the bed level of the sedimented aggregate layer corresponds to the interface between the liquid level of the supernatant liquid portion and the sedimented aggregate layer of the sediment concentration portion, and the measured level value is a measuring instrument (ultrasonic transducer described later). 13A etc.) to the bed level. Therefore, it is shown that the larger the level value is, the lower the bed level is, and the smaller the level value is, the higher the bed level is.

The level measurement unit 13 can be composed of, for example, an ultrasonic transducer 13A and a measurement processing unit 13B. The ultrasonic transducer 13A is provided so as to be located above the supernatant liquid portion in the thickener 10, transmits ultrasonic waves in the vertical direction, and receives the reflected waves. The measurement processing unit 13B measures the time until the ultrasonic transducer 13A transmits ultrasonic waves and receives the reflected wave, and calculates the distance to the object based on the time. The level measuring unit 13 can be configured by, for example, a commercially available ultrasonic level meter.

Specifically, in the level measuring unit 13, an ultrasonic transducer 13A provided so as to be located above the supernatant liquid portion transmits ultrasonic waves, and the liquid level of the supernatant liquid portion and the sedimentation aggregate layer of the sedimentation concentration portion are transmitted. Upon receiving the reflected wave at the interface with, the measurement processing unit 13B measures the time from the transmission of the ultrasonic wave to the reception of the reflected wave, and calculates the distance to the interface based on the time. By such a method, the level measuring unit 13 measures the level of the settling aggregate layer over time.

The level measuring unit 13 is not limited to the ultrasonic level measuring device described above, and a radio wave level measuring device, an optical level measuring device, or the like may be used.

[Rake rotation detector]
The rake rotation detecting unit 14 detects the rotation of the rake provided in the thickener 10 based on the level measurement of the sedimented aggregate layer over time by the level measuring unit 13. Specifically, the rake rotation detection unit 14 detects a maximum value and a minimum value in the level measurement value within a predetermined set time from the result of the level measurement of the sedimentation aggregate layer over time by the level measurement unit 13. It is confirmed whether or not the rake 11 is rotating, that is, whether the rake 11 is rotating or stopped is detected.

The rake rotation detection unit 14 can be configured by, for example, a monitoring unit 14A and a rotation detection determination unit 14B.

The monitoring unit 14A is electrically connected to the measurement processing unit 13B in the level measurement unit 13 described above, and the calculation result by the measurement processing unit 13B so that the reflection state of the ultrasonic wave by the level measurement unit 13 can be monitored. Is displayed on the screen. Since the level measuring unit 13 measures the level of the sedimentation aggregate layer over time (continuously), the measurement result is displayed on the screen by the monitoring unit 14A to change the level value over time. Can be grasped.

The rotation detection determination unit 14B detects the presence or absence of rotation of the rake 11 based on the change in the level measurement value displayed on the screen by the monitoring unit 14A. Specifically, the rotation detection determination unit 14B determines whether or not the maximum value and the minimum value are detected within a predetermined set time from the transition of the level measurement value over time displayed on the screen by the monitoring unit 14A. confirm.

≪2. Thickener rake rotation detection method ≫
As a result of analyzing the relationship between the rake 11 of the thickener 10 and the level (bed level) of the sedimentation aggregate layer, the present inventor has analyzed that the amount of slurry flowing into the thickener 10 is constant during rotation of the rake 11. , It was confirmed that the bed level increased or decreased at regular intervals.

That is, when the rake 11 is rotating, the bed level gradually increases when the blade 11b constituting the rake 11 approaches under the ultrasonic transducer 13A of the level measuring unit 13, and under the ultrasonic transducer 13A. After passing through, it gradually decreases and increases or decreases at regular intervals. This means that as the blade 11b of the rake 11 rotates, the upper surface of the sedimentation aggregate layer (the interface between the supernatant liquid portion and the sedimentation aggregate layer) becomes "wave" and is located above the supernatant liquid portion. It is considered that the ultrasonic wave radiated in the vertical direction from the ultrasonic transducer 13A detects the "wave" and is expressed as a change in the level value. Therefore, during the rotation of the rake 11, the waveform (waveform of the level measurement value) obtained from the level measurement unit 13 becomes a characteristic sawtooth wave.

Here, FIG. 2 is a graph showing an example of a transition of the level measured value of the settling aggregate layer displayed on the screen by the monitoring unit 14A of the rake rotation detection unit 14. That is, it is a waveform diagram which shows the time-dependent change of the measured value of the level of the sedimentation aggregate layer continuously measured by a level measuring unit 13. As shown in FIG. 2, when the rake 11 is rotating (on the left side when facing the center of the graph of FIG. 2), the waveform of the level measurement value is a characteristic sawtooth wave.

In the level measurement of FIG. 2, an ultrasonic transducer 13A is provided in the level measuring unit 13, and the distance in the depth direction of the ultrasonic transducer 13A is set to 0 m at the tip of the ultrasonic transducer 13A and in the vertical direction from there. The distance to the bottom (slope) 10b of the thickener 10 (sickener main body 10A) facing toward is set to be about 4 m.

Looking at FIG. 2 in more detail, it can be seen that during the rotation of the rake 11, the maximum value and the minimum value appear in the level measurement values at a constant cycle accompanying the rotation of the rake 11 (according to the rotation speed). Therefore, in continuous level measurement, when the maximum value and the minimum value appear during the predetermined installation time [t] when the waveform of the level measurement value is observed over time, the rake 11 rotates. Can be considered to be. On the other hand, when the maximum value and the minimum value do not appear in the level measurement value within the predetermined set time [t], it can be considered that the rotation of the rake 11 has stopped.

Therefore, in the thickener device 1 according to the present embodiment, the rotation detection determination unit 14B in the rake rotation detection unit 14 measures the level of the settling aggregate layer by the level measurement unit 13 within a predetermined set time [t]. It is characterized in that the rotation of the rake 11 is detected depending on the presence or absence of detection of the maximum value and the minimum value. Then, the rotation detection determination unit 14B determines that the rake 11 is rotating when the maximum value and the minimum value are detected within the predetermined set time [t], and stops the rake 11 when it is not detected. Judge that you are doing.

The presence or absence of the maximum value and the minimum value can be evaluated by using the point where the slope of the level value changes from positive to negative and from negative to positive.

In FIG. 2, during the set time "A", the maximum value and the minimum value of the level measured value are detected. Therefore, from this result, it can be detected that the rake 11 is rotating. On the other hand, in the continuous level measurement, the maximum value was detected but the minimum value was not detected during the set time "B". Therefore, from this result, it can be detected that the rake 11 is stopped.

According to such a thickener device 1, the rotation of the rake 11 can be efficiently detected, and for example, the influence on the next process due to deterioration of sickening or the like can be effectively suppressed.

The set time [t] for confirming the detection of the maximum value and the minimum value can be appropriately determined based on the rotation speed of the rake 11. For example, the time required for one blade 11b constituting the rake 11 to make one rotation (one rotation) can be set. Specifically, it can be about 5 to 15 minutes.

Further, the rake rotation detection unit 14 not only detects the maximum value and the minimum value within a predetermined set time [t], but also calculates the difference (difference value) between the maximum value and the minimum value. good. When the maximum value and the minimum value are detected in the predetermined set time [t] and the difference value is equal to or larger than the set value, it is considered that the rake 11 is rotating normally. On the other hand, if the maximum value and the minimum value are not detected, or if the maximum value and the minimum value are detected but the difference value is less than the set value, the rake 11 is stopped or abnormal rotation is in progress. It is considered to be. In this way, by calculating the difference value between the maximum value and the minimum value and using it as a determination index for the presence or absence of rotation of the rake 11, false detection can be prevented and the presence or absence of rotation of the rake 11 can be determined with higher accuracy. At the same time, it is possible to detect a rotation abnormality or an abnormal stop of the rake 11.

The difference value between the maximum value and the minimum value is not particularly limited, and can be determined, for example, according to the depth of the supernatant liquid portion and the sedimentation concentration portion formed in the thickener 10. For example, it can be about 0.05 m to 0.15 m.

When the rake rotation detection unit 14 detects that the rake 11 is stopped by detecting the rotation of the rake 11 based on the presence or absence of detection of the maximum value and the minimum value within a predetermined set time, for example, the monitoring unit At 14A, an error (ALARM) may be issued on the screen display. This enables the worker to go to the site and confirm the event at an early stage. Further, not only the error alarm on the screen display but also the alarm may be issued by a siren or the like.

The control of a series of rake rotation detections in the thickener device 1 according to the present embodiment can be executed by hardware or by software. When a series of processes are executed by software, the programs constituting the software are installed on a computer or the like from a network or a recording medium. The computer may be a computer embedded in dedicated hardware. Further, the computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

1 Thickener device 10 Thickener 10A Thickener body 10a Cylindrical outer frame 10b Bottom 10c Slurry recovery port 10d Lid 11 Lake 11a Rotating shaft 11b Blade 12 Feedwell 12a Slurry supply pipe 12b Additive supply pipe 12c Dispersion cone 13A Ultrasonic Transducer 13B Measurement processing unit 14 Lake rotation detection unit 14A Monitoring unit 14B Rotation detection judgment unit

Claims (7)

A thickener device that performs sedimentation separation processing on the slurry to be processed.
A thickener having a rake that rotates about a rotation axis and causing the slurry to settle by the rotation of the rake to form a supernatant liquid portion at the upper part and a sedimentation concentration part at the lower part.
A level measuring unit that measures the level of the sedimented aggregate layer of the sedimentation and concentration unit over time in a non-contact manner by a measuring instrument provided so as to be located above the supernatant liquid portion of the thickener.
A rake rotation detecting unit for detecting the rotation of the rake based on the level measurement of the sedimented aggregate layer by the level measuring unit is provided.
The rake rotation detecting unit detects the presence or absence of rotation of the rake based on the presence or absence of detection of the maximum value and the minimum value within a predetermined set time in the measurement of the level of the sedimented aggregate layer by the level measuring unit. Device. The rake rotation detection unit determines that the rake is rotating when a maximum value and a minimum value are detected within a predetermined set time in the measurement of the level of the sedimentation aggregate layer by the level measurement unit. The thickener device according to claim 1, wherein if the rake is not detected, the rake is determined to be stopped. A thickener device that performs sedimentation separation processing on the slurry to be processed.
A thickener having a rake that rotates about a rotation axis and causing the slurry to settle by the rotation of the rake to form an upper supernatant liquid portion and a lower sedimentation concentration portion.
A level measuring unit that measures the level of the sedimented aggregate layer of the sedimentation and concentration unit over time in a non-contact manner by a measuring instrument provided so as to be located above the supernatant liquid portion of the thickener.
A rake rotation detecting unit for detecting the rotation of the rake based on the level measurement of the sedimented aggregate layer by the level measuring unit is provided.
The rake rotation detection unit detects the maximum value and the minimum value within a predetermined set time in the measurement of the level of the sedimentation aggregate layer by the level measurement unit, and calculates the difference value between the maximum value and the minimum value. Then, the presence or absence of rotation of the rake is detected by comparing the difference value with a predetermined set value.
Thickener device. The level measuring unit is
Ultrasonic waves provided so as to be located above the supernatant liquid portion of the thickener, transmit ultrasonic waves, and receive reflected waves at the interface between the liquid level of the supernatant liquid portion and the sedimentation aggregate layer of the sedimentation concentration portion. The thickener according to any one of claims 1 to 3, wherein the transducer measures the time from the transmission of the ultrasonic wave to the reception of the reflected wave of the ultrasonic wave, and calculates the distance to the interface based on the time. Device. A method for detecting rake rotation in a thickener device.
The sedimentation concentrate layer is formed by irradiating the interface between the liquid level of the upper supernatant liquid portion formed by the rotation of the rake provided in the thickener device and the sedimentation concentration layer of the lower sedimentation concentration portion with ultrasonic waves. Level is measured over time ,
A thickener rake rotation detection method for detecting the presence or absence of rotation of the rake based on the presence or absence of detection of the maximum value and the minimum value at the measured level within a predetermined set time. If the maximum value and the minimum value are detected at the measured level within a predetermined set time, it is determined that the rake is rotating, and if it is not detected, it is determined that the rake is stopped. The rotation detection method of the thickener rake according to claim 5 . A method for detecting rake rotation in a thickener device.
The sedimentation concentration layer is formed by irradiating the interface between the liquid level of the upper supernatant liquid portion formed by the rotation of the rake provided in the thickener device and the sedimentation concentration layer of the lower sedimentation concentration portion with ultrasonic waves. Level is measured over time,
By detecting the maximum value and the minimum value at the measured level within a predetermined set time, calculating the difference value between the maximum value and the minimum value, and comparing the difference value with the predetermined set value. Detects the presence or absence of rotation of the rake
Thickener rake rotation detection method.

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