JP6825452B2 - Metal powder cooling device - Google Patents

Description

The present invention relates to a metal powder cooling device, and more specifically, efficiently cools a heated metal powder in a short time after a heat treatment or a drying treatment is performed under high temperature conditions. With respect to a metal powder cooling device that can.

The metal powder can be obtained, for example, by precipitating and generating metal particles from a solution containing a reducing agent, or by pulverizing a metal compound obtained by crystallization from the solution into particles by a pulverizer or the like. The metal powder thus obtained is heat-treated under high temperature conditions, or the metal powder is washed and then dried at a high temperature to remove water and the like adhering to the metal powder. .. After that, the metal powder (heated powder) heated by the treatment under high temperature conditions is cooled to a predetermined temperature or lower before being transferred to the next step in which, for example, the processing treatment is performed.

Since the thermal conductivity between metal powders is generally poor in cooling the metal powder, the powder is stirred and cooled in the cooling device by stirring or the like, or the cooling device is vibrated. This is done by a method such as cooling by exchanging heat with the can body while flowing the powder charged in the apparatus.

Specifically, the cooling of the powder in the cooling device includes indirect cooling that exchanges heat with the refrigerant flowing in the cooling jacket provided in the device, and the powder and heat while blowing cold air directly into the cooling device. There is a direct cooling method for replacement.

However, in these methods, the heat conduction of the powder is very poor, the cooling time is inevitably long, and efficient operation cannot be performed. Further, when the cooling time of the powder is long, there is also a problem that the amount of foreign matter mixed in the powder due to the wear of the cooling device and the powder increases. Further, when the cooling processing time of the powder is long, it is necessary to increase the size of the cooling equipment in order to increase the processing amount and perform efficient operation.

On the other hand, in order to speed up the cooling process of powder, for example, when trying to increase the stirring capacity in the device, a device with high hardness is sprayed on the can body and stirring blades to minimize wear. Although it will be necessary to implement these measures, these measures will greatly increase the equipment cost. In addition, since it is impossible to completely eliminate the wear between the equipment and the powder, it is necessary to carry out regular maintenance of the equipment, but if the equipment is enlarged and measures for low wear are taken, the maintenance cost will also increase. It will be expensive and maintenance itself will be difficult.

In addition, Patent Document 1 includes, as a cement cooling system, a pumping facility for pneumatically feeding cement from a transport vehicle to a storage tank facility and a facility for cooling air below a predetermined temperature, and cools the cement during transportation. A method of cooling using air is disclosed. However, the technique described in Patent Document 1 is a technique relating to cooling of cement, and is not easily applicable to cooling of metal powder.

Japanese Unexamined Patent Publication No. 2015-136861

Powder Technology Overview 2014-2015, Japan Powder Technology Association, p88-105

The present invention has been proposed in view of such circumstances, and an object of the present invention is to provide a metal powder cooling device capable of efficiently executing a cooling process on a metal powder in a short time.

As a result of diligent studies, the present inventor causes the heated metal powder to be sent through a flow pipe that has taken in the cooling gas, and heat is generated by contact with the cooling gas in the flow pipe. We have found that it is possible to efficiently cool the metal powder in a short time while allowing the metal powder to be exchanged, and have completed the present invention.

(1) In the first invention of the present invention, a flow pipe for flowing the metal powder, which is connected to the lower end of the charging tank into which the heated metal powder is charged, and the flow pipe are provided. A storage tank for storing the metal powder flowed through the metal powder, a transfer tank provided on the downstream side of the storage tank, and a lower end portion of the transfer tank are connected to the next step from the transfer tank. The metal powder is provided with a transfer pipe for transferring the metal powder to the processing apparatus of the above, and the flow pipe is provided with a cooling gas intake port for taking in cooling gas at a connection point with the input tank. The metal powder is a metal powder cooling device that is flown while being cooled in the flow pipe by a cooling gas taken in from the cooling gas intake port.

(2) The second invention of the present invention is the same as the first invention, which comprises a blower provided above the storage tank and sucking the cooling gas to flow the metal powder. It is a cooling device.

(3) In the third invention of the present invention, in the first or second invention, the temperature of the metal powder stored in the storage tank is measured in the storage tank via the flow pipe. It is a metal powder cooling device provided with a temperature sensor.

(4) In the fourth invention of the present invention, in the third invention, the transfer pipe is provided with a switching valve for switching the transfer destination of the metal powder transferred from the transfer tank, and the temperature. When the temperature of the metal powder measured by the sensor exceeds a predetermined temperature, the metal powder is returned to the storage tank via the circulation pipe connected to the transfer pipe at the point of the switching valve. It is a metal powder cooling device.

(5) In the fifth aspect of the present invention, in any one of the first to fourth inventions, the transfer pipe has a cooling gas intake port for taking in cooling gas at a connection point with the transfer tank. It is a metal powder cooling device that is provided and cools the metal powder that passes through the transfer pipe.

According to the present invention, it is possible to provide a metal powder cooling device capable of efficiently executing a cooling process on a metal powder in a short time.

It is a schematic diagram which shows the structural example of the metal powder cooling apparatus.

Hereinafter, a specific embodiment of the present invention (hereinafter, referred to as “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.

FIG. 1 is a schematic view showing a configuration of a metal powder cooling device (hereinafter, also simply referred to as “cooling device”) according to the present embodiment. The metal powder cooling device 1 includes a charging tank 11 into which the heated metal powder (heated powder) is charged, and a flow pipe 12 connected to the lower end of the charging tank 11 for flowing the heated powder. , A storage tank 13 for storing the heated powder flowed through the flow pipe 12, a transfer tank 14 provided on the downstream side of the storage tank 13, and a lower end portion of the transfer tank 14. The transfer pipe 15 for transferring the metal powder from the transfer tank 14 to the processing apparatus in which the next step is performed is provided.

The cooling device 1 is provided with a cooling gas intake port 12A for taking in the cooling gas at a connection point with the charging tank 11 in the flow pipe 12, and the heating powder is discharged from the cooling gas intake port 12A. It is characterized in that it is sent while being cooled in the flow pipe 12 by the cooling gas taken in.

Further, the cooling device 1 is provided with a control unit 30 that controls the transfer destination of the metal powder. The control unit 30 transfers the metal powder to the processing apparatus in which the next step is performed based on the measured temperature of the metal powder that has been flowed while being cooled in the flow pipe 12, or the storage tank again. It controls whether to circulate and transfer to 13.

According to the cooling device 1 having such a configuration, when the heated powder passes through the flow-through pipe, it is flown while being cooled by the cooling gas, so that the cooling process can be efficiently performed in a short time. it can. In addition, since it is not necessary to provide additional equipment such as a stirring blade and a vibration device as in the conventional case and separately provide a cooling device for cooling while applying stirring and vibration, foreign matter is mixed in the metal powder. There is no risk, and equipment costs can be effectively suppressed. Further, by causing the control unit 30 to circulate the metal powder based on a predetermined standard, the surely cooled metal powder can be transferred to the next process.

Specifically, according to the cooling device 1 according to the present embodiment, a predetermined amount of metal powder can be cooled at about 4 ° C. to 5 ° C./min. In a conventional cooling device, for example, a cooling device that cools while stirring, the cooling rate was about 1 ° C. to 2 ° C./min when the same amount of metal powder was cooled.

Hereinafter, each configuration of the cooling device 1 will be described more specifically.

[Injection tank]
The charging tank 11 is a tank for temporarily storing the heated metal powder. The charging tank 11 is not particularly limited, and a known storage tank can be used. Further, a valve 11a capable of adjusting the charging of heated powder into the flow pipe 12 can be provided at the lower end of the charging tank 11, that is, at the connection point with the flow pipe 12 described later.

Generally, a metal powder is produced by a wet method or the like and then heat-treated under high temperature conditions, or is washed and then dried, so that the metal powder is in a state of heated powder heated to a high temperature. Such high-temperature heated powder is cooled to a temperature of, for example, about 50 ° C. or lower before being subjected to a predetermined treatment in the next step. In the cooling device 1 according to the present embodiment, the manufactured heated powder is temporarily stored in the charging tank 11 and is sent to the process of the next step while being cooled through the flow pipe 12 described later.

[Drafting piping]
The flow-through pipe 12 is a pipe for flowing out the heated powder. One end of the flow pipe 12 is connected to the lower end of the charging tank 11 and the other end is connected to the storage tank 13, so that the heated powder is flowed between the charging tank 11 and the storage tank 13. The arrow F1 in FIG. 1 indicates the flow direction of the heated powder through the flow pipe 12.

Here, the flow-through pipe 12 is provided with a cooling gas intake port 12A for taking in the cooling gas at a connection point with the charging tank 11. For example, a cooling gas such as air cooled to a predetermined temperature is supplied to the cooling gas intake port 12A, and the cooling gas is taken into the flow pipe 12 through the cooling gas intake port 12A. In this way, in the cooling device 1, the cooling gas is taken into the flow pipe 12 for flowing the heated powder, and when the heated powder comes into contact with the cooling gas, heat is exchanged and the heated powder is exchanged. Can be flowed while cooling, and the cooling process can be efficiently performed in a short time.

Examples of the cooling gas taken into the flow pipe 12 include cooled air. By air-flowing with the cooled air in this way, the heated powder can be flowed while being efficiently cooled. The cooling gas is not limited to air, and may be an inert gas such as nitrogen (N ₂ ) gas or argon gas to prevent oxidation, or air from which water at a low dew point has been removed. It may be present, and it can be appropriately determined in relation to the metal powder to be sent.

Further, the cooling gas can be taken into the flow pipe 12 at a predetermined wind speed. By allowing the cooling gas having a predetermined wind speed to be taken in, the heated powder can be efficiently cooled and the inside of the flow pipe 12 can be smoothly flowed.

Further, as will be described in detail later, a blower 17 is provided above the storage tank 13 so that the blower 17 sucks in the cooling gas taken into the flow pipe 12 and flows, thereby causing the heated powder to flow. You can also do it.

[Storage tank]
The storage tank 13 is connected to a flow pipe 12, and is flowed through the flow pipe 12 to charge and store heated powder. As described above, in the flow-through pipe 12, the heated powder is sent while being cooled by the cooling gas, so that the heated powder charged through the flow-through pipe 12 is cooled to a predetermined degree. It is a state metal powder.

The storage tank 13 is not particularly limited, and a known storage tank can be used. Further, the storage tank 13 may be provided with a cooling member such as a cooling jacket on the outer periphery of the tank, for example. As a result, the metal powder charged and stored in the storage tank 13 from the draft pipe 12 can be cooled.

The storage tank 13 is provided with a bag filter unit 16 on the upper portion thereof, and collects dust so that the produced metal powder is not discharged to the outside through the blower 17 and returns it to the inside of the tank. Further, since the blower 17 is connected to the bag filter unit 16 and the inside of the storage tank 13 becomes a negative pressure due to the suction by the blower 17, the flow of the heated powder sent through the flow pipe 12 Send. Further, as will be described later, the metal powder circulated and returned from the transfer pipe 15 can be efficiently circulated and transferred.

The bug filter unit 16 is not particularly limited, and a heat-resistant filter such as a known dust collector can be used. Further, the blower 17 is not particularly limited as long as it can pump particles, and known blowers such as centrifugal blowers and axial flow blowers can be used.

Further, the storage tank 13 is provided with a temperature sensor 13T inside, and measures the temperature of the stored metal powder. The temperature sensor 13T measures the temperature of the metal powder that has been flown while being cooled through the flow pipe 12 and stored in the storage tank 13, and transmits the measured temperature information of the metal powder to the control unit 30. .. As a result, the control unit 30 can determine whether or not the metal powder stored in the storage tank 13 is in a state of being cooled to an arbitrarily set target temperature.

The storage tank 13 is connected to the transfer tank 14 on the downstream side, and the metal powder stored in the storage tank 13 is then transferred to the transfer tank. A rotary valve 18 can be provided at the connection point between the storage tank 13 and the transfer tank 14. As a result, the amount of metal powder transferred from the storage tank 13 to the transfer tank 14 can be appropriately adjusted according to the pipe length, the flow rate, and the amount of cooled air.

[Transfer tank]
As described above, the transfer tank 14 is provided on the downstream side of the storage tank 13, and temporarily stores the metal powder charged from the storage tank 13. A transfer pipe 15 described later is connected to the transfer tank 14, and basically, the metal powder transferred to the processing apparatus in which the next process is performed is temporarily stored via the transfer pipe 15. ..

As the transfer tank 14, a known storage tank can be used.

[Transfer piping]
The transfer pipe 15 is a pipe for transferring the metal powder from the transfer tank 14 to the processing apparatus in which the next process is performed. One end of the transfer pipe 15 is connected to the lower end of the transfer tank 14, and the other end is connected to the processing device of the next process, and the metal powder is transferred from the transfer tank 14 to a predetermined processing device. The arrow F2 in FIG. 1 indicates the transfer direction of the metal powder through the transfer pipe 15.

Here, in the transfer pipe 15, a cooling gas intake port 15A for taking in the cooling gas can be provided at a connection point with the transfer tank 14. Similar to the cooling gas intake port 12A provided in the flow pipe 12, a cooling gas such as cooled air is supplied to the cooling gas intake port 15A provided in the transfer pipe 15, and the cooling gas is taken. Cooling gas is taken into the transfer pipe 15 through the inlet 15A. By taking the cooling gas into the transfer pipe 15 in this way, the metal powder transferred to the next step can be transferred while being cooled. In addition, the transfer speed of the metal powder is increased, and retention and the like can be prevented. At this time, even in the transfer to the next process via the transfer pipe 15, the same configuration as the storage tank 13, the bag filter unit 16 and the blower 17 described above may be provided.

As shown in FIG. 1, the supply sources of the cooling gas taken in from the cooling gas intake port 12A of the flow pipe 12 and the cooling gas intake port 15A of the transfer pipe 15 can be shared. , The same cooling gas can be taken in.

A circulation pipe 19 is connected to the transfer pipe 15 so as to branch at a predetermined position. Further, at the connection point (point) between the transfer pipe 15 and the circulation pipe 19, a switching valve 20 for switching the transfer destination of the metal powder transferred from the transfer tank 14 is provided.

The circulation pipe 19 connected to the transfer pipe 15 is a pipe for circulating and transferring the metal powder whose transfer destination has been switched by the switching valve 20. The other end of the circulation pipe 19 is connected to the front flow pipe 12 connected to the storage tank 13, and a circulation switching valve 21 is provided at the connection point between the circulation pipe 19 and the flow pipe 12. ing. The circulation switching valve 21 switches the metal powder (charge source) charged into the storage tank 13, and the metal powder flowed from the charging tank 11 via the flow pipe 12. Is charged, or the metal powder circulated and transferred via the circulation pipe 19 is charged. In this way, by circulating and transferring the metal powder through the circulation pipe 19 and returning it to the flow-through pipe 12, the metal powder can be cooled again by the cooling gas. The arrow F3 in FIG. 1 indicates the transfer direction of the metal powder through the circulation pipe 19.

Specifically, when transferring the metal powder supplied from the transfer tank 14, the metal powder is cooled to the target temperature or less based on whether or not the metal powder is below the target temperature arbitrarily set. The resulting metal powder is directly transferred to the processing apparatus in the next process through the transfer pipe 15. On the other hand, since the metal powder in a state exceeding the target temperature is a powder that has not been sufficiently cooled yet, it passes through the circulation pipe 19 via the transfer pipe 15 based on the transfer switching by the switching valve 20. Circulated and transferred. As described above, since the other end of the circulation pipe 19 is connected to the draft pipe 12, the metal powder is circulated and transferred through the circulation pipe 19 and then cooled again by the cooling gas.

[Control unit]
The control unit 30 controls the transfer destination of the metal powder. The control unit 30 is electrically connected to the temperature sensor 13T provided in the storage tank 13 and the switching valve 20 provided in the middle of the transfer pipe 15 (the connection point with the circulation pipe 19). Based on the measured temperature of the metal powder measured in the storage tank 13, it is controlled whether the metal powder is transferred to the processing apparatus where the next step is performed or is circulated and transferred to the storage tank 13 again. ..

Specifically, when the temperature of the metal powder that has been sent while being cooled in the flow pipe 12 in the storage tank 13 is measured by the temperature sensor 13T, the control unit 30 measures the temperature by the temperature sensor 13T. Receive information about. The control unit 30 determines whether or not the measured temperature of the received metal powder is equal to or lower than a target temperature (set target temperature) arbitrarily set in advance. For example, when the set target temperature is set to 50 ° C., the control unit 30 determines whether the measurement temperature of the metal powder is 50 ° C. or lower or exceeds 50 ° C., and if the measurement temperature is 50 ° C. or lower, the temperature is determined. It is determined that the metal powder is sufficiently cooled, and if the temperature exceeds 50 ° C., it is determined that the metal powder is not yet sufficiently cooled.

Then, the control unit 30 controls the transfer destination of the metal powder via the transfer pipe 15 based on the determination of the degree of cooling of the metal powder based on the measured temperature. That is, when the control unit 30 determines that the measurement temperature of the metal powder is equal to or lower than the set target temperature and the metal powder is sufficiently cooled, the control unit 30 remains as it is via the transfer pipe 15 (without switching the switching valve 20). The metal powder is transferred to the processing apparatus where the next step is performed. On the other hand, when it is determined that the measurement temperature of the metal powder exceeds the set target temperature and the metal powder is not sufficiently cooled, the switching valve 20 is switched and transferred to the circulation pipe 19 via the transfer pipe 15. .. As described above, the circulation pipe 19 is connected to the flow pipe 12 through which the cooling gas flows, and circulates and transfers the metal powder that has not been sufficiently cooled.

In this way, the control unit 30 accurately controls the transfer destination of the metal powder based on the measurement temperature of the metal powder. As a result, the cooling device 1 can reliably and efficiently perform the cooling treatment on the metal powder, and can effectively prevent the metal powder still hot from being transferred to the next process. it can.

Further, in addition to the control based on the measurement temperature of the metal powder by the temperature sensor 13T as described above, the control unit 30 controls the metal powder to be intentionally circulated a plurality of times (for example, 5 times). May be good. For example, when the metal powder supplied from the transfer tank 14 is transferred via the transfer pipe 15, the control unit 30 intentionally switches the switching valve 20 to circulate and transfer the metal powder to the circulation pipe 19. Repeat 5 times. Then, after the five cycles are completed, the metal powder stored in the storage tank 13 is measured by the temperature sensor 13T, and based on the measured temperature, the metal powder is circulated again or the next step is performed via the transfer pipe 15. Controls whether to transfer to the processing device of.

As described above, according to the metal powder cooling device 1 according to the present embodiment, when the heated metal powder passes through the flow pipe 12, it is flowed while being cooled by the cooling gas. Therefore, the cooling process can be efficiently performed in a short time. Further, since it is not necessary to separately provide a cooling device for cooling while stirring as in the conventional case, there is no possibility that foreign matter is mixed in the metal powder, and the equipment cost and the like can be effectively suppressed.

Further, by providing the control unit 30 to circulate the metal powder based on a predetermined standard, the surely cooled metal powder can be transferred to the next process.

In the present embodiment, the mode in which the cooling gas is taken in from the cooling gas intake port 12A of the flow pipe 12 and the cooling gas intake port 15A of the transfer pipe 15 is shown, but the present invention is not limited to this. For example, a similar cooling gas intake port may be provided at a position in the middle of the draft pipe 12 or the transfer pipe 15, and the cooling gas may be taken in from the middle part.

1 Cooling device 11 Input tank 12 Flow pipe 12A Cooling gas intake 13 Storage tank 13T Temperature sensor 14 Transfer tank 15 Transfer pipe 15A Cooling gas intake 16 Bug filter unit 17 Blower 18 Rotary valve 19 Circulation pipe 20 Switching Valve 21 Circulation switching valve 30 Control unit

Claims (5)

A flow pipe that is connected to the lower end of the charging tank into which the heated metal powder is charged and that flows the metal powder.
A storage tank for storing the metal powder flowed through the flow pipe, and
A transfer tank provided on the downstream side of the storage tank and
A transfer pipe connected to the lower end of the transfer tank and for transferring the metal powder from the transfer tank to the processing apparatus in the next process.
With
The flow pipe is provided with a cooling gas intake port for taking in cooling gas at a connection point with the input tank.
The metal powder is fed while being cooled in the flow pipe by the cooling gas taken in from the cooling gas intake port, and is also flown .
Based on the measured temperature of the metal powder measured in the storage tank, the metal powder is transferred to the processing apparatus where the next step is performed, or is circulated and transferred to the storage tank again. A metal powder cooling device further provided with a control unit for control . The metal powder cooling device according to claim 1, further comprising a blower provided above the storage tank to suck in the cooling gas and flow the metal powder. The storage tank is provided with a temperature sensor electrically connected to the control unit for measuring the temperature of the metal powder stored in the storage tank via the flow pipe. The metal powder cooling device according to 1 or 2. The transfer pipe is provided with a switching valve electrically connected to the control unit for switching the transfer destination of the metal powder transferred from the transfer tank.
When the temperature of the metal powder measured by the temperature sensor exceeds a predetermined temperature, the metal powder is returned to the storage tank via the circulation pipe connected to the transfer pipe at the point of the switching valve. The metal powder cooling device according to claim 3. The transfer pipe is provided with a cooling gas intake port for taking in the cooling gas at a connection point with the transfer tank, and the metal powder passing through the transfer pipe is cooled. Claims 1 to 4 The metal powder cooling device according to any one of the above items.

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