JP2620771B2 - Pulverizer with oxygen concentration controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverizer having an oxygen concentration controller for pulverizing highly reactive metal materials in a low oxygen atmosphere.

[0002]

2. Description of the Prior Art In order to safely pulverize a reactive material, for example, coal, a pulverizer equipped with a control device or an alarm for the concentration of carbon monoxide or oxygen is used. For example, when finely pulverizing coal in an air atmosphere, when the oxygen concentration of the atmosphere becomes a set value, for example, 15% or more, and the carbon monoxide concentration becomes a set value, for example, 200 ppm or more, the inert gas such as steam and CO ₂ becomes Perform flow control,
By reducing the activity of the atmosphere, the pulverizer is prevented from generating fire or explosion.
No. 28613).

[0003] In the case of finely pulverizing a metal-based material, in order to avoid undesirably excessive surface oxidation, the pulverization is performed in a low oxygen atmosphere.

[0004]

However, in the method of pulverizing a material in an air atmosphere, the method of pulverizing the material while reducing the activity of the atmosphere is not effective for pulverizing a reactive material such as coal. However, the use of a gas consisting of oxygen atoms as an inert gas also makes it impossible to form a sufficiently low oxygen atmosphere in order to pulverize highly reactive metal-based materials. There is a possibility that the desired properties may not be exhibited due to excessive surface oxidation.

The present invention has been made in order to solve the above-mentioned problems of the prior art. In order to finely pulverize highly reactive metal materials in a low oxygen atmosphere, rare gases are used as inert gases. Provided is a fine pulverizing apparatus provided with an oxygen concentration control device that pulverizes in an inert gas atmosphere using a gas, for example, argon, and controls the oxygen concentration in the pulverizing system so as to suppress surface oxidation of the material. The purpose is to:

[0006]

In order to achieve the above object, according to the present invention, a pulverizing apparatus for pulverizing a material in an inert gas atmosphere through a pulverizing system is connected to an inlet side of the pulverizing apparatus. An inert gas flow control valve provided in the inert gas introduction path, a blower that is provided after the pulverizing device to flow gas in the system, and a pressure control valve provided on the blower inlet side, In the provided fine pulverizing device, an oxygen concentration detector that detects the oxygen concentration of the gas in the system upstream of the fine pulverizing device, and the detected oxygen concentration of the oxygen concentration detector is compared with a set concentration, and the difference between the oxygen concentration and the oxygen concentration is determined by the deviation. An oxygen controller that controls the inert gas flow control valve so as to have a specified concentration, a pressure detector that detects the pressure of the gas in the system at the inlet of the blower, and a pressure detected by the pressure detector is compared with a set pressure. To that deviation A pressure controller for controlling the pressure control valve so that the pressure becomes the specified pressure Ri and is characterized by comprising comprises a.

[0007]

In this way, outside air is prevented from entering the system, and the oxygen concentration in the system is automatically controlled so as to suppress surface oxidation of the material by introducing an inert gas using a rare gas. , And can be pulverized efficiently without deteriorating the properties of highly reactive metal-based materials and the like.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a pulverizing apparatus having an oxygen concentration control apparatus according to an embodiment of the present invention.

FIG. 1 shows an example of a fine pulverizer for performing a closed circuit operation, and reference numeral 10 denotes an oxygen controller, including a pressure controller. Reference numeral 12 denotes a fine pulverizing device. The material supplied from the material supply device 14 is dispersed and introduced into a fine pulverizing system 30 and finely pulverized in the fine pulverizing device 12. A classifier 16, a separator 18, a pressure control valve 32, and a blower 20 are arranged in series at the outlet side of the pulverizer 12. The classifier 16 classifies the finely pulverized product into coarse particles and fine powder,
The coarse particles are returned to the fine pulverizer 12 and repeatedly pulverized, and the fine powder is subjected to solid / gas separation in the separator 18 to separate and collect the crushed product 19. The gas in the system 30 from the separator 18 is supplied to the blower 20 through the pressure control valve 32.
Fluidized by The gas in the fine pulverizing system 30 is circulated and flowed, and is again introduced into the fine pulverizing device 12 from the blower 20, and a part of the gas is discharged to the outside air.

An inert gas introduction passage 28 is connected to the fine pulverizing system 30 on the inlet side of the fine pulverizing device 12, and 26 is an inert gas flow control valve. As the inert gas, a rare gas, for example, argon which is a monoatomic gas is used,
Water vapor of a hydrogen compound, which is an inert gas of a conventional example,
Unlike triatomic molecules such as carbon dioxide composed of oxygen compounds, they exhibit chemical reactivity with extremely low reactivity.

Reference numeral 22 denotes an oxygen concentration detector for detecting the oxygen concentration of the gas in the system 30. For example, a zirconia solid electrolyte type oxygen sensor is suitable. It is installed at a position on the upstream side of the material feeder 14 to prevent dust and the like from acting when detecting the oxygen concentration. The output signal 23 converted into an electric quantity from the oxygen concentration detector 22 can be digitally processed through an A / D converter, but the embodiment shows a case of analog processing. The output signal 23 is input to an oxygen controller 24, and 25 is an oxygen concentration setting unit of the oxygen controller 24.

The oxygen controller 24 has a required control circuit. The oxygen controller 24 performs a control operation in accordance with a detected oxygen concentration condition of the oxygen concentration detector 22 in comparison with a set concentration of an oxygen concentration setter 25 and a deviation signal thereof. Then, an operation signal 27 for controlling the inert gas flow control valve 26 is output so that the oxygen concentration becomes the specified concentration. The set density of the setter 25 can be made variable. Then, the operation signal 27 is input to an electro / pneumatic converter (not shown), and is given as an air signal to an inert gas flow control valve 26 for controlling the inert gas flow, so that the oxygen concentration of the gas in the system 30 becomes a specified concentration. Is controlled as follows.

The control operation of the oxygen controller 24 can be multi-position control, for example, a three-position control operation.
The operation of the inert gas flow control valve 26 is performed at three positions, so that the configuration of the control system can be simplified.

When a highly reactive metal material, for example, aluminum is pulverized in the pulverizer 12, the oxygen concentration of the gas in the pulverization system 30 is adjusted to a specified concentration, for example, 0.1.
7 to 1.2% is set so that the surface oxidation of aluminum can be suppressed.

Reference numeral 33 denotes a pressure detector for detecting the pressure of the gas in the system 30. The pressure detector 33 is installed at the inlet of the blower 20, and an output signal 35 converted into an electric quantity from the pressure detector 33 is input to a pressure controller 34. Reference numeral 36 denotes a pressure setting unit 36 of the pressure controller 34.

The pressure controller 34 has a required control circuit. The pressure controller 34 compares the pressure with a pressure set by a pressure setter 36 in accordance with a detected pressure condition of the pressure detector 33, and performs a control operation based on a deviation signal thereof. An operation signal 37 for controlling the pressure control valve 32 so that the pressure becomes a specified pressure is output. The set pressure of the setter 36 can be made variable. Then, the operation signal 37 is input to an electro-pneumatic converter (not shown), and is supplied as an air signal to the pressure control valve 32 for controlling the gas pressure, so that the pressure of the gas in the system 30 is controlled to a specified pressure. . The gas pressure in the pulverizing system 30 is a specified pressure,
For example, since the pressure is controlled to be 0 to 100 MPa, intrusion of outside air into the system 30 is suppressed, and an increase in the oxygen concentration of the gas in the system 30 is avoided.

With this configuration, when a highly reactive metal-based material is pulverized in the pulverizer 12, the inert gas using a rare gas is introduced into the pulverization system 30 accompanying the material. The atmospheric concentration due to oxygen is also set to a specified concentration, and the intrusion of outside air into the system 30 is suppressed, and the oxygen concentration in the system 30 can be automatically controlled so as to suppress surface oxidation of the material. The fine pulverization can be efficiently performed without deteriorating the properties of the material and the like.

[0019]

As described above, according to the present invention, when finely pulverizing a highly reactive metal material, the infiltration of outside air into the fine pulverization system is suppressed and the oxygen concentration in the system is reduced. Introducing an inert gas using a rare gas to automatically control the surface oxidation of the material under a low oxygen atmosphere so that it can be pulverized without deteriorating the properties of highly reactive metal materials. A great effect can be achieved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a pulverizing apparatus provided with an oxygen concentration control device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Oxygen concentration control apparatus 12 Fine crushing apparatus 20 Blower 22 Oxygen concentration detector 24 Oxygen controller 26 Inert gas flow control valve 28 Inert gas introduction path 30 Fine crushing system 32 Pressure control valve 34 Pressure controller

Claims (1)

(57) [Claims] 1. A pulverizing device for pulverizing a material in an inert gas atmosphere through a pulverizing system, and an inert gas flow control provided in an inert gas introduction passage connected to an inlet side of the pulverizing device. A valve, a blower disposed downstream of the pulverizing device for flowing the gas in the system, and a pressure control valve provided on the inlet side of the blower; in a system upstream of the pulverizing device, An oxygen concentration detector for detecting the oxygen concentration of the gas, and comparing the detected oxygen concentration of the oxygen concentration detector with a set concentration, and controlling the inert gas flow control valve such that the oxygen concentration becomes a specified concentration by a deviation thereof. An oxygen controller, a pressure detector that detects the pressure of gas in the system at the inlet of the blower, and a pressure control valve that compares a detected pressure of the pressure detector with a set pressure, and that the pressure becomes a specified pressure by a deviation thereof. Control And a pressure controller, comprising: an oxygen concentration control device.