JP2012223713A - Water atomizing solid-liquid separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water atomizing solid-liquid separator used for responding to concentration change of stock solution and capable of continuing operation even if a current value of a differential speed motor is increased.SOLUTION: The water atomizing solid-liquid separator 10 separates and dehydrates metal particles manufactured by a water atomizing method from the stock solution constituted of water and the metal particles. For separating/dehydrating the metal particles from the stock solution, rotation frequency of a screw conveyer 12 by the differential speed motor 19 is decreased with respect to rotation frequency of a rotary bowl 11 by a main speed motor 17 so as to have the differential speed. The water atomizing solid-liquid separator 10 includes an ammeter 21 for detecting a current value of the differential speed motor 19 and a control device 20 for automatically controlling rotation of the differential speed motor 19 at predetermined differential speed corresponding to the current value so as to respond to concentration change of the stock solution.

Description

  The present invention relates to a solid-liquid separator for water atomization that separates metal particles produced by a water atomization method from water as a stock solution.

  For example, metal particles (powder) that are materials for producing a sintered metal are produced by a water atomization method. In this water atomization method, molten metal stored in a tundish (a saucer) is caused to flow out of a pouring nozzle provided at the lower part of the tundish, and high-pressure water is injected into the flow of molten metal to thereby remove the molten metal. This is a method for producing metal particles which is pulverized to form powder. In the post-process for producing metal particles by this water atomization method, it is necessary to separate fine metal particles from a large amount of water into metal powder.

  In a conventional technique as a method for separating and dewatering from a stock solution in which metal particles and water are combined in water atomization production, a filter (for example, see Patent Document 1) or a vacuum dehydrator (for example, Patent Document 2). For example).

However, since the filter system and the vacuum dehydrator use a filter cloth, there is a problem that fine particles of metal particles are clogged in the filter when the stock solution is separated and dehydrated. For this reason, there are problems that the recovery rate is low and the moisture content is high.
In addition, since the water atomization method is batch production, it is indispensable to continuously separate and dehydrate the separation and dehydration process at a high recovery rate and low water content in order to produce high-quality metal particles. There was a problem that this continuous processing could not be performed. Furthermore, after dehydration, the metal particles exposed to air have a problem that they are oxidized and deteriorated with the passage of time.

JP 2009-35799 A (paragraph 0034) JP-A-10-280001 (paragraph 0010) JP 2005-144279 A

In order to solve these problems, it was strongly requested to use a vertical decanter centrifuge (hereinafter referred to as a solid-liquid separator). However, conventional solid-liquid separators separate solids from stock solutions. In order to dehydrate, the rotation speed of the screw conveyor by the differential speed electric motor is lowered with respect to the rotation speed of the rotating bowl by the main speed electric motor to give a differential speed, and the solid content concentration in the stock solution is constant. Based on conditions, this differential speed is made constant (for example, refer to Patent Document 3).
For this reason, when the concentration of the undiluted solution increases, the load (current value) of the differential speed motor increases, so that there is a problem that the thermal drops due to the temperature increase of the differential speed motor and stable operation cannot be performed.

Therefore, the present invention has been developed to solve these problems at once by improving the operation so that the operation can be continued even if the concentration of the stock solution changes, and clogging such as a filter is performed. The metal particles can be separated and dehydrated at a high recovery rate and low water content, and can be continuously separated and dehydrated. After separation and dehydration, the metal particles are not exposed to air and oxidized, and are solidified for water atomization. In response to changes in the concentration of the undiluted solution using a liquid separator, the differential speed motor can continue to operate even if the current value increases, and the rotation of the differential speed motor can be controlled automatically. It is an object to provide a solid-liquid separator for water atomization that can reduce the generation of CO ₂ by energy saving by optimization of speed.

  According to the first aspect of the present invention, the cylindrical portion (11b) connected to the upper end plate (11c) and the lower tapered portion (11a) are integrally formed into a vertical cylindrical shape, and the upper end plate ( 11c) has a separation liquid overflow port (11e) provided with a weir plate, and is provided coaxially within the rotating bowl (11) and a cylindrical rotating bowl (11) rotatably supported by the shaft, A rotatable screw conveyor (12) that rotates at a differential speed with the rotating bowl (11) via a differential speed device (18), and an intubation hole in the upper end plate (11c) of the cylindrical portion of the rotating bowl (11) (11d) is inserted into the axial center portion, and a stock solution supply pipe (15) for supplying the stock solution to the cylindrical portion and a radius in the rotating bowl (11) connected to the lower end of the stock solution supply pipe (15) The main part is composed of a flow dividing rib plate (16) provided in a direction, A vertical solid-liquid separator (10) for water atomization that separates and dehydrates metal particles produced by the atomization method from a stock solution composed of water and metal particles, and detects the current value of the differential speed motor (19). An ammeter (21) and a control device (20) for automatically controlling the rotation of the differential speed motor (19) at a predetermined differential speed corresponding to the current value are provided.

The invention described in claim 2 is the solid-liquid separator for water atomization according to claim 1, wherein the automatic control of the rotation of the differential speed motor (19) by the control device (20) is the difference. The speed difference is kept at 4 min ⁻¹ until the current value of the high-speed motor (19) reaches 70% of the rated current, and when the current value becomes 71 to 75%, the speed difference is set to plus 1. 5min ⁻¹ , if the current value is 76 to 80%, the differential speed is positive, 6min ⁻¹ plus 2 and if the current value is 81 to 85%, the differential speed is positive 3 7min ^-1, the speed difference is when the current value becomes the value of 86-90%, 8min ^-1 plus 4, the speed difference is when the current value becomes the value of 91% and 95% , 9min ^-1 plus 5, the speed difference is when the current value becomes the value of 96 to 100%, 1 plus 6 min ^-1 increases the differential speed in the case became less current value, and decreases the differential rate.

  The invention described in claim 3 is the solid-liquid separator for water atomization (10) according to claim 1, wherein nitrogen gas is supplied into the solid-liquid separator for water atomization (10). It is characterized by.

  According to the first aspect of the invention, the rotation of the differential speed motor is automatically controlled by a solid-liquid separator for water atomization that has not been used so far in an apparatus that separates and dehydrates metal particles produced by the water atomization method from a stock solution. Equipped with a control device, the rotational speed of the rotating bowl of the main speed motor is reduced by lowering the rotational speed of the screw conveyor by the differential speed motor to give a differential speed, and the current value of the differential speed motor to respond to changes in the concentration of the stock solution , And the rotation is controlled at a predetermined differential speed corresponding to this current value, so that there is no clogging like a filter and the metal particles can be recovered at a high recovery rate. The recovered metal particles have a low water content. Separation and dehydration can be performed. Moreover, the solid-liquid separator for water atomization which can perform a continuous separation-dehydration process can be provided.

According to the invention of claim 2, when the load (current value) is up to 70% of the rated current, the differential speed is kept constant at 4 min ⁻¹ , and the load increases from 70% to 5%. the differential speed, plus 1 5min ^-1, the speed difference when the load becomes 76-80%, plus 2 6min ^-1, the speed difference when the load becomes 81-85%, plus 3 7min ⁻¹ , when the load is 86-90%, the differential speed is 8min ⁻¹ plus 4, when the load is 91-95%, the differential speed is 9min ⁻¹ plus the load 5 When the speed becomes 96 to 100%, the differential speed is increased to 10 min ⁻¹ of plus 6, and when the load is less than that, the rotational speed of the fine differential speed that decreases the differential speed by the automatic control, it is possible to reduce the electrical energy, the generation of CO ₂ that can be reduced It is possible to provide a atomizing solid-liquid separator.
By the way, energy saving by optimizing the differential speed can reduce 2.25kw per hour of rotation.
Since the amount of CO ₂ generated is 0.36 kg per 1 kWh, it can be reduced to 2.25 kw × 22 h × 250 days × 0.36 = 4.5 tons, and 4.5 tons of CO ₂ annually.

  According to the invention of claim 3, by supplying nitrogen gas into the solid-liquid separator for water atomization, air is replaced with nitrogen gas, and the metal particles are exposed to oxygen in the air and oxidized. Can be prevented. Furthermore, since the metal particles are filled with nitrogen gas, it can be prevented from being oxidized and denatured over time.

It is an expanded sectional view of the solid-liquid separator for water atomization used with the separation dehydration method of the present invention. It is a model diagram which shows arrangement | positioning of the control apparatus of the solid-liquid separator for water atomization of this invention. It is a flowchart which shows the flow which controls rotation of a differential speed motor.

An embodiment of a solid-liquid separator for water atomization according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, from a raw solution supply port A at the top of a solid-liquid separator for water atomization 10 according to the present invention, a raw solution in which metal particles produced by water atomization are combined with water is produced. For example, by supplying with a metering pump and rotating the screw conveyor 12 to be described later slower (differential speed) than the rotation of the rotating bowl 11 to be described later, the stock solution is separated into metal particles and water and the dehydration process is continued. The separated liquid water is discharged from the separated liquid outlet B, and the separated solid metal particles are discharged from the separated solid outlet C. In order to prevent oxidation of the metal particles, nitrogen supply ports D and E for supplying nitrogen gas are provided inside the solid-liquid separator 10 for water atomization.
The differential speed is a rotation that reduces the rotational speed of the screw conveyor by the differential speed motor to give a difference in rotational speed to the rotational speed of the rotating bowl by the main speed motor in order to separate and dehydrate solids from the stock solution. The speed difference. By providing a phase difference in the rotation by this differential speed, the solid content separated by the specific gravity difference can be conveyed downward by the differential speed rotation of the screw conveyor 12 and discharged to the outside.
In addition, the undiluted solution here refers to water in a state in which solid metal particles are mixed. Moreover, this water (liquid) is also called a separated liquid, and the solid substance to be separated is also called a separated solid substance.

<Configuration of solid-liquid separator for water atomization>
The solid-liquid separator 10 for water atomization according to the present invention is connected to a tapered portion 11a having a solid material discharge port 13 on the lower small diameter end side, and an upper large diameter end side of the tapered portion 11a, and a weir on the upper end plate 11c. A rotating bowl 11 composed of a cylindrical portion 11b having a separation liquid overflow port 11e provided with a plate (not shown), is provided on the same shaft in the rotating bowl 11, and is connected via the differential speed device 18 A screw conveyor 12 that rotates with the rotating bowl 11 at a slight differential speed is provided.

  Further, a stock solution supply pipe 15 for supplying the stock solution, a diverting rib plate 16 for distributing the stock solution to the inner wall of the rotating bowl 11, and a lower portion of the rotating bowl 11, and a slight difference from the rotational speed of the rotating bowl 11. A differential speed device 18 that rotates the screw conveyor 12 with a speed, and a main shaft that is disposed on a main shaft below the differential speed device 18 and that rotates the rotating bowl 11 at high speed via pulleys 11f and 11g and a belt 11h. A speed motor 17, a differential speed motor 19 provided below the differential speed device 18, which rotates the screw conveyor 12 at low speed via pulleys 12 f and 12 g and a belt 12 h via the differential speed device 18, and The solid-liquid separator 10 for water atomization from the gantry 2 disposed and fixed above, the control device 20 for controlling the main speed motor 17, the differential speed device 18, and the differential speed motor 19. The main unit is configured.

  A high speed shaft 3 (see the lower part of FIG. 1) for rotating the rotating bowl 11 at a high speed is rotatably supported by a bearing (not shown) provided at a shaft end portion. The low speed shaft 4 connected to the screw conveyor 12 is rotatably supported by a bearing attached to the inner diameter of the high speed shaft 3.

<Configuration of rotating bowl>
The rotating bowl 11 is formed so as to be rotatable integrally with an upper end plate 11c, a cylindrical portion 11b connected to the upper end plate 11c, and a lower tapered portion 11a.

<Configuration of screw conveyor>
The screw conveyor 12 is mounted on the inner peripheral surface of the rotating bowl 11, and includes a screw conveyor shaft 12a and screw conveyor blades 12b in which the outer periphery of the screw conveyor shaft 12a is formed in a spiral shape. The screw conveyor 12 is driven through a differential speed device 18 using the differential speed motor 19 as a drive source. The screw conveyor 12 is driven at a differential speed proportional to the difference between the rotational speed of the rotating bowl 11 and the rotational speed of the differential speed motor 19. Rotate.

<Configuration of stock solution supply pipe>
The stock solution supply pipe 15 is a cylindrical pipe having a flange formed at the top. It is inserted from an intubation hole 11 d projecting into the center of the upper end plate 11 c of the cylindrical portion 11 b of the rotating bowl 11, and the stock solution is supplied to the diverting rib plate 16 in the rotating bowl 11.
When the stock solution is supplied and the rotating bowl 11 rotates, the stock solution forms a liquid surface F on the inner peripheral surface of the cylindrical portion 11b of the rotary bowl 11 by centrifugal force, and the separated solution (water) is discharged. ) Overflows from the separated liquid overflow port 11e provided with a weir plate on the upper end plate 11c, and is discharged from the separated liquid outlet B to the outside of the apparatus.
For discharging solid matter, a solid matter discharge port 13 is provided on the lower small diameter end side of the tapered portion 11a, and the solid matter transported to the taper portion 11a side by the screw conveyor 12 is dehydrated. From the separated solid matter discharge port C, it is discharged out of the machine by an outboard conveyor (not shown) provided in a pit (not shown).
The stock solution may be supplied from an unillustrated metal particle production apparatus using a water atomizing method via a stirring tank, and then supplied from the stock solution supply pipe 15 with a metering pump, or directly without passing through the stirring tank. The stock solution may be supplied from the supply pipe 15.

<Configuration of shunt rib plate>
The diverting rib plate 16 is a stock solution distribution jig arranged radially in the radial direction in the rotating bowl 11. The flow of the stock solution is divided vertically, and the stock solution is transferred to the inner wall of the rotating bowl 11. The shape of one of the flow dividing rib plates 16 is a divided member having a substantially constant width from the center of the rotating bowl 11 toward the inner wall when viewed from a plane (radial section), and is viewed from a front sectional view along the axial direction. And a trapezoidal shape (a shape that spreads toward the end) from the center side to the inner wall side of the rotating bowl 11, and the flow of the stock solution from the stock solution supply pipe 15 is vertically divided in the axial direction. That is, the center side and the inner wall side are open.

The diverting rib plate 16 is connected to the lower end of the stock solution supply pipe 15 inserted into the hollow screw conveyor 12, and is provided with narrow grooves (not shown) that are formed radially in the radial direction of the screw conveyor shaft 12a. Inserted into and fixed. The stock solution supply pipe 15 and the adjacent diverting rib plate 16 are pipes communicating with each other.
The lower bottom side (inner wall side of the rotating bowl 11) where the diverting rib plate 16 is open is located extending to the outer wall of the screw conveyor shaft 12a. By providing the diverting rib plate 16 in this way, the stock solution can be reliably supplied to the inner wall of the rotating bowl 11 by changing the flow of the stock solution from the axial direction to the radial direction. It is possible to secure the residence time necessary for separating the objects.

<Main speed motor>
As the main speed motor 17, a three-phase induction motor or a three-phase synchronous motor is used. For constant torque / inverter control, the rotational speed is automatically shifted by controlling the frequency. The rotation speed of the main speed motor 17 is for obtaining a necessary centrifugal effect, and is determined by the properties of the stock solution and the required performance. The rotation speed of the main speed motor 17 is, for example, high speed (1000 to 3500 min ⁻¹ ), and the speed reducer shaft 3 is rotated by the pulleys 11f and 11g via the belt 11h. When the speed reducer shaft 3 rotates, the rotating bowl 11 rotates.

<Differential speed motor>
As the differential speed motor 19, a three-phase induction motor or a three-phase synchronous motor is used. For constant torque / inverter control, the rotational speed is automatically shifted by controlling the frequency. The rotation of the differential speed motor 19 is controlled at an optimum differential speed with respect to the rotation of the main speed motor 17 via the differential speed device 18.
As for the rotation of the differential speed motor 19, the speed reducer input shaft 4 is rotated by the pulleys 12f and 12g through the belt 12h. When the speed reducer input shaft 4 rotates, the screw conveyor shaft 12 is rotated at a low speed in the same direction via the differential speed device 18.

<Differential speed device>
The differential speed device 18 is a planetary gear speed reducer that decelerates in three stages. The speed reducer shaft 3 of the differential speed device 18 and the speed reducer input shaft 4 of the screw conveyor shaft 12a are on the same core and rotate in the same direction. The differential speed device 18 decelerates the number of rotations corresponding to the reduction ratio per one differential speed revolution. Therefore, in order to obtain a large differential speed, the reduction ratio must be reduced. However, if the torque is extremely reduced, a large torque is required of the motor, resulting in an increase in the output of the motor and an increase in power consumption. However, the optimal reduction ratio and output torque are set by suppressing the increase in power consumption.
Here, the speed ratio of the differential speed device 18 is, for example, 150. Thus, for example, the rotational speed of the main speed motor 17 2500min ^-1, rotational speed 1900Min ^-1 differential speed electric motor 19, and if, the differential speed is, (2500-1900) ÷ 150 = 4min -1 , and the
If rotational speed 2500min ^-1, rotation speed of the differential speed electric motor 19 1000min ^-1, and, differential speed becomes ^{(2500-1000) ÷ 150 = 10min -1} .

<Output and control method of differential speed motor>
In order to reduce the output of the differential speed motor 19, a large reduction ratio is required. However, if the reduction ratio is increased, the differential speed range is narrowed, so that a large reduction ratio is not adopted. Further, the torque of the differential speed motor 19 increases in inverse proportion to the rotational speed.
Therefore, by setting the differential speed motor 19 to be used as a constant torque / inverter control and setting the base rotational speed near the normal differential speed (low speed side), a higher torque can be obtained than at the maximum rotational speed.
Further, by setting the torque characteristics to a constant torque specification, a constant torque can be obtained from the low speed range to the base rotational speed. By setting the specifications of the motor as described above, a constant torque can be maintained over the entire differential speed range, and stable operation for 24 hours can be performed by the differential speed control operation corresponding to the concentration. A solid-liquid separator for atomization can be provided.

Next, the operation of the water-atomizing solid / liquid separator 10 will be described.
When the main speed motor 17 is automatically activated, the rotating bowl 11 rotates at a high speed (1000 to 3500 min ⁻¹ ), for example. Then, when the differential speed motor 19 is automatically activated, the rotational speed of the differential speed motor 19 is set to a low rotational speed at which the differential speed is 4 min ⁻¹ with respect to the rotational speed of the main speed motor 17, The screw conveyor 12 rotates. At this time, if the current value of the differential speed motor 19 is equal to or less than 70% of the rated current, the rotation is maintained at the differential speed of 4 min ⁻¹ .

Nitrogen gas is supplied from the nitrogen supply ports D and E, and the air in the machine is replaced with nitrogen gas. Further, when the stock solution is supplied from the stock solution supply pipe 15 of the stock solution supply port A at the upper part of the rotating bowl 11, the stock solution collides with the flow dividing rib plate 16 and is uniformly divided radially, and receives the centrifugal force and is uniformly dispersed. To do. Solids (metal particles) in the stock solution supplied from the diverting rib plate 16 to the cylindrical portion 11b of the rotating bowl 11 are subjected to centrifugal force and settle on the inner wall side of the cylindrical portion 11b. The settled solid matter is separated by the screw conveyor blade 12b of the screw conveyor 12, and then dehydrated by the centrifugal force in the tapered portion 11a and conveyed to the solid matter discharge port 13. Then, the dehydrated metal particles are dropped from the solid discharge port 13 and discharged outside the apparatus by a belt conveyor or the like provided in a pit (not shown).
On the other hand, the water of the separated liquid separated in the rotating bowl 11 and separated by the screw conveyor blades 12b of the screw conveyor 12 moves upward, and the separated liquid overflow port 11e provided in the upper end plate 11c of the cylindrical portion 11b. Overflows the dam plate and is discharged from the separation liquid outlet B to the outside of the apparatus. Nitrogen gas is contained 78% in the air, is nonflammable and inert.

Conventionally, the differential speed control of the solid-liquid separator may have a fixed operating condition because the concentration of the stock solution is constant and the supply condition of the stock solution is constant without changing the flow rate.
Since the supply conditions were constant, the properties of the separation liquid and the separated solid were also constant.
However, in water atomization production, it was found difficult to keep the concentration of the stock solution constant.Therefore, a range was defined for the properties (moisture content) of the metal particles that are solids to be separated, and within an acceptable range. A method to control the differential speed was devised. This is because the operation control (including sequence) and the setting of the specifications of the devices (including the differential speed motor and the main speed motor) that enable it are changed, so that stable continuous operation can be performed.

For example, since the metal powder after water atomization has a large specific gravity, it is difficult to disperse in water and settles quickly. Although it is circulated and dispersed by a pump or the like, the torque generated during dehydration increases or decreases due to irregular concentration changes in the stock solution.
Therefore, the differential speed is automatically controlled by the control device 20 in accordance with the generated torque in order to stabilize the operation state of the differential speed motor 19 for controlling the differential speed and the differential speed device 18.
FIG. 2 is a schematic diagram showing the arrangement of the control device of the solid-liquid separator for water atomization.
As shown in FIG. 2, a control device 20 is provided outside the machine. The differential speed motor 19 and the control device 20 are electrically connected, and an ammeter 21 is disposed. The main speed motor 17 and the control device 20 are also electrically connected, and the rotation speeds of the main speed motor 17 and the differential speed motor 19 can be changed.
Then, in order to cope with the change in the concentration of the stock solution, the current value of the differential speed motor 19 is detected and calculated by a calculation circuit (not shown) in the control device 20 based on the value of the current value to determine the differential speed. The speed of the differential speed motor 19 is changed and controlled.

To detect the current value of the differential speed motor 19, the electric signal of the ammeter 21 is continuously taken into the sequencer, and the optimum differential speed is obtained and changed instantaneously based on the flowchart of FIG.
For example, when there is a change in the concentration of the stock solution and the concentration decreases, the current value of the differential speed motor 19 also decreases, so that the differential speed is reviewed and reduced to an appropriate differential speed.
In this way, in response to changes in the concentration of the stock solution, it is possible to suppress high-load operation by controlling the rotation of the differential speed motor 19 so that the rotation of the differential speed motor 19 becomes an appropriate differential speed. Since the output of the differential speed motor 19 is stabilized in the low output direction, energy saving is 30%, and a considerable amount of CO ₂ can be reduced per year.

Here, control of the control device 20 of the solid-liquid separator 10 for water atomization that can cope with changes in the concentration of the stock solution in the water atomization production facility of the present invention will be described.
FIG. 3 is a flowchart showing a flow for controlling the rotation of the differential speed motor.
As shown in FIG. 3, step S01 detects whether or not the current value of the differential speed motor 19 is equal to or less than 70% of the rated current with the ammeter 21 (see FIG. 2), and is less than or equal to 70% of the rated current. In this case (S01 / Yes), the process proceeds to step S02, and the control device 20 controls the rotation by lowering the rotational speed of the differential speed motor 19 from the rotational speed of the main speed motor 19, for example, by setting the differential speed to 4 min ^−1. .
If it is equal to or greater than 70% of the rated current value of the differential speed motor 19 (S01 / No), the process proceeds to step S03.
In the step S03, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is 71 to 75% of the rated current in the same manner as described above, and if the current value is 71 to 75% of the rated current (S03 / Yes) ) Proceeds to step S04, and the control device 20 controls the rotation by setting the differential speed of the differential speed motor 19 to 5min ⁻¹ of plus 1. When the value is 71% to 75% or more of the rated current of the differential speed motor 19 (S03 / No), the process proceeds to step S05.
In step S05, it is detected whether or not the current value of the differential speed motor 19 is 76 to 80% of the rated current. If the current value is within the range (S05 / Yes), the process proceeds to step S06, and the control device 20 performs the differential speed motor. The rotational speed is controlled by setting the differential speed of 19 to 6min ⁻¹ of plus 2.
When it is 76 to 80% or more of the rated current (S05 / No), the process proceeds to step S07.
In step S07, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is 81 to 85% of the rated current. If within the range (S07 / Yes), the process proceeds to step S08, and the control device 20 The rotational speed is controlled by setting the differential speed of the differential speed motor 19 to 7 min ⁻¹ of plus 3.
If the value is 81 to 85% or more of the rated current (S07 / No), the process proceeds to step S09.

In step S09, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is 86 to 90% of the rated current. If it is within the range (S09 / Yes), the process proceeds to step S10, and the control device 20 The rotational speed is controlled by setting the differential speed of the differential speed motor 19 to 8 min ⁻¹ of plus 4.
When the value is 86% to 90% or more of the rated current (S09 / No), the process proceeds to step S11.
In step S11, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is 91 to 95% of the rated current. If within the range (S11 / Yes), the process proceeds to step S12, and the control device 20 Controls the rotation by setting the differential speed of the differential speed motor 19 to 9 min ⁻¹ of plus 5.
If the value is 91 to 95% of the rated current or more (S11 / No), the process proceeds to step S13.
In step S13, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is 96 to 100% of the rated current. If it is within the range (S13 / Yes), the process proceeds to step S14, and the control device 20 Controls the rotation by setting the differential speed of the differential speed motor 19 to 10 min ⁻¹ of plus 6.
When the value is 96 to 100% or more of the rated current value (S13 / No), the process proceeds to step S15.
In step S15, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is 101 to 105% of the rated current. If it is within the range (S15 / Yes), the process proceeds to step S16, and the control device 20 activates and sends an alarm (not shown), for example, generating an alarm. Moreover, when it is more than the value of 101-105% of a rated current value (S15 / No), it progresses to step S17.
In step S17, the ammeter 21 detects whether or not the current value of the differential speed motor 19 is equal to or greater than 106% of the rated current. If the current value is equal to or greater than 106% (S17 / Yes), the process proceeds to step S18. The device 20 activates the alarm device (22), for example, generates an alarm sound, and stops the main speed motor 17 and the differential speed motor 19.

As mentioned above, although one embodiment using the solid-liquid separator for water atomization of the present invention was described, the present invention is not limited to the above-described one embodiment, and can be implemented with appropriate modifications. .
Although the differential speed with respect to the current value is increased stepwise as plus 1, plus 2,..., It may be increased steplessly as plus 1 → 1.1 → 1.2.
In addition to displaying a warning text on a CRT screen of an operation panel (not shown), an alarm may be generated by an alarm sound from a speaker or flashing light from a patrol light. The power transmission means is disclosed as a pulley / belt system, but a gear system or other power transmission means may be employed.
In addition, the effect of using a vertical solid-liquid separator is that when the solid-liquid separator is stopped, the horizontal type accumulates water and solids inside, and there is a high risk of deterioration such as oxidation. At the time of stopping, the solid content is discharged outside the machine, so it is difficult to oxidize.
Furthermore, the metal particles have been improved in performance, with a 95% recovery rate of 99.5% and a 20% moisture content of 10% or less.
Further, by supplying nitrogen gas to replace the air in the apparatus, the metal particles are not exposed to oxygen in the air after separation and dehydration to be oxidized.
Furthermore, using a solid-liquid separator for water atomization, it is possible to perform efficient operation without unevenness and waste in response to changes in the concentration of the stock solution, and the rotation of the differential speed motor 19 is controlled to optimize the differential speed. For example, in the case of the differential speed motor 19 of 7.5 kw, it becomes possible to reduce the power consumption of 2.25 kwh per hour and contribute to the reduction of CO ₂ of 4.5 tons per year.

1 Floor (basic)
DESCRIPTION OF SYMBOLS 2 Base 2a Lower housing 2b Upper housing 3 Reduction gear shaft 4 Reduction gear input shaft 5,6 Bearing 10 Solid-liquid separator for water atomization 11 Rotating bowl 11a Taper portion 11b Cylindrical portion 11c Upper end plate 11d Intubation hole 11e Separation liquid overflow Port 12 Screw conveyor 12a Screw conveyor shaft 12b Screw conveyor blade 13 Solid material discharge port 14 Separation liquid discharge port 15 Stock solution supply pipe 16 Dividing rib plate 17 Main speed motor 18 Differential speed device 19 Differential speed motor 20 Control device 21 Ammeter 22 Alarm A A Stock solution supply port B Separation solution outlet C Separation solid discharge port D, E Nitrogen supply port

Claims (3)

A separated liquid in which a cylindrical portion (11b) connected to the upper end plate (11c) and a lower tapered portion (11a) are integrally formed in a vertical cylindrical shape, and a weir plate is provided on the upper end plate (11c) A cylindrical rotating bowl (11) having an overflow port (11e) and rotatably supported;
A rotatable screw conveyor (12) provided coaxially in the rotating bowl (11) and rotating at a differential speed with the rotating bowl (11) via a differential speed device (18);
A stock solution supply pipe (15) that is inserted into the shaft center portion from the intubation hole (11d) of the upper end plate (11c) of the cylindrical portion of the rotating bowl (11) and supplies the stock solution to the cylindrical portion;
A main part is constituted by a diverting rib plate (16) provided in the radial direction in the rotating bowl (11) connected to the lower end of the stock solution supply pipe (15),
A vertical solid-liquid separator (10) for water atomization that separates and dehydrates metal particles produced by the water atomization method from a stock solution composed of water and metal particles,
An ammeter (21) for detecting a current value of the differential speed motor (19);
A control device (20) for automatically controlling the rotation of the differential speed motor (19) at a predetermined differential speed corresponding to the current value;
A solid-liquid separator for water atomization (10), comprising: The automatic control of the rotation of the differential speed motor (19) by the control device (20) is to maintain the differential speed at 4 min ⁻¹ until the current value of the differential speed motor (19) is 70% of the rated current. When the current value is 71 to 75%, the differential speed is 5 min ^{−1 of} plus 1, and when the current value is 76 to 80%, the differential speed is 6 min of plus 2. ⁻¹ , when the current value is 81 to 85%, the differential speed is 7 min ^{−1 of} 3 plus, and when the current value is 86 to 90%, the differential speed is 4 plus. 8 min ⁻¹ , the differential speed when the current value is 91 to 95%, plus 5 min 9 ⁻¹ , the differential speed when the current value is 96 to 100%, The differential speed is automatically increased to 10 min ^-1 of plus 6, and when the current value is less than that, the differential speed is automatically reduced. The solid-liquid separator (10) for water atomization of Claim 1 characterized by the above-mentioned.   The solid-liquid separator (10) for water atomization according to claim 1, wherein nitrogen gas is supplied into the solid-liquid separator (10) for water atomization.

Images