JPS6041601B2 - Control method for argon purification equipment - Google Patents

Description

Detailed Description of the Invention The present invention compresses, cools, and compresses raw air taken from the atmosphere.
An argon purification device that adds hydrogen to the crude argon collected from the crude argon column of an air separation device that collects products such as oxygen, nitrogen, and argon through rectification, and then reacts to remove oxygen from the crude argon. This relates to a control method.

The composition of the crude argon collected from the crude argon column of the air separation device is approximately 96% Ar), 2% 00, 2% No, and 2H.

An argon purifier is used to remove O2 from +02 to river 20. The conventional control method for argon purification equipment detects the flow rate of crude argon and the oxygen concentration in the crude argon, calculates the amount of hydrogen addition necessary for the reaction, and automatically controls the amount of hydrogen supplied. There is. Generally, in argon purification equipment, a palladium catalyst is used to promote the reaction between oxygen in crude argon and added hydrogen. This reaction using a palladium catalyst is carried out at a temperature of the catalyst layer of 200 to 400 DEG C., and this temperature is determined by the temperature rise of the fluid due to the heat of reaction between oxygen and hydrogen. When the temperature of the palladium catalyst tank falls below 200° C., the reaction slows down and oxygen in the crude argon cannot be completely removed. Conversely, if the temperature of the palladium catalyst tank exceeds 5000C, the reaction will occur explosively.
Not only is it dangerous, but it also reaches its limit in terms of material strength. The crude argon collected from the crude argon column of the air separation equipment contains about 2% oxygen, and when hydrogen is added to carry out a catalytic reaction while maintaining the oxygen concentration, the temperature of the fluid increases due to the heat of reaction. exceeds 500℃. Therefore, an argon compressor is generally provided to compress the crude argon, and the capacity of this compressor is set to be 1.5 to 3 times the amount of crude argon extracted from the crude argon column of the air separation device. In order to compensate for the lack of crude argon in relation to the capacity of the argon compressor, the oxygen-free crude argon discharged from the palladium catalyst tank is cooled, and then a portion of it is returned to the suction side of the Arco 7 compressor. mixed with crude argon from the argon column;
The oxygen concentration at the discharge side of the discharge machine of the argon compressor, that is, at the inlet of the palladium catalyst tank, is lowered to around 1%02 to suppress the rise in temperature of the fluid due to the reaction. However, in conventional control methods, the rotation speed of the argon compressor is constant, so the discharge amount is constant, and the flow rate of crude argon supplied from the crude argon column of the air separation device and the oxygen concentration in the crude argon vary. There is a problem that it is not possible to follow the In other words, when the flow rate of crude argon supplied from the crude argon column of the air separation device and the oxygen concentration in the crude argon are large, the oxygen concentration at the inlet of the palladium catalyst tank, which is the reaction column, becomes high and an explosion of oxygen and hydrogen occurs. On the other hand, if the crude argon flow rate and the oxygen concentration in the crude argon are low, the oxygen concentration at the inlet of the palladium catalyst tank will be low and the reaction temperature in the palladium catalyst tank will be low, making it unstable. In addition, power is wasted by compressing the bypass flow rate of argon from which oxygen has been removed, which is larger than necessary. The purpose of the present invention is to constantly perform a stable reaction and to reduce power consumption despite fluctuations in the flow rate of crude argon supplied from a crude argon column and the oxygen concentration in the crude argon. .

The present invention detects the flow rate of crude argon and the oxygen concentration in the crude argon, controls the rotation speed of the Arco 7 compressor in response to fluctuations in the crude argon flow rate and the oxygen concentration in the crude argon,
In addition, by automatically controlling the bypass flow rate that bypasses deoxygenated argon to the suction side of the argon compressor according to the rotational speed of the argon compressor, the oxygen concentration at the inlet of the palladium catalyst tank can be kept constant and stable at all times. It is designed to cause a reaction to occur.

Hereinafter, an example of an argon purification apparatus implementing the control method according to the present invention will be explained with reference to the drawings.

1 is an oxygen analyzer that measures the oxygen concentration in crude argon supplied from the crude argon column, 2 is a flow meter that measures the flow rate of crude argon, and 3 is an automatic control valve 4 that increases or decreases the amount of crude argon supplied. Flow rate indicating controller that controls the flow rate at a constant level, 5
6 is a calculator that calculates the amount of hydrogen required for the reaction based on the oxygen concentration detected by the oxygen analyzer 1 and the crude argon flow rate detected by the flow meter 2; A flow rate indicating controller that automatically controls the hydrogen supply amount, 8 indicates the oxygen concentration detected by the oxygen analyzer 1, and the flow meter 2
A calculation unit 9 calculates the required rotation speed of the argon compressor 10 based on the crude argon flow rate detected by the calculation unit 8, and a rotation unit 9 that automatically controls the discharge flow rate of the argon compressor 10 by controlling the rotation speed of the motor based on the calculated value of the calculation unit 8. 11 is a palladium catalyst tank; 12 and 13 are pressure indicating regulators on the suction side and discharge side of the argon compressor 10;
A part of the argon from which oxygen has been removed by the automatic control valve 14 is bypassed to the suction side of the argon compressor 10 so that the flow rates on the suction side and the discharge side are almost equal in order to balance the suction and discharge pressures of the argon compressor. .

The composition of the crude argon supplied from the crude argon column through conduit 21 is approximately 96% Arl2%02, 2% N2;
The amount of crude argon supplied is controlled to be constant by the flow rate indicator controller 3 and the automatic control valve 4 according to the increase/decrease operation, and the amount of added hydrogen supplied from the conduit 26 that is introduced from the conduit 22 to the argon compressor 10 is calculated. It is added to the crude argon discharged from the Realcon compressor 10 through the conduit 27 through the flow rate indicator controller and the automatic control valve 7, and is added to the crude argon discharged from the realcon compressor 10.
It is then introduced into the palladium catalyst tank 11.

Most of the argon from which oxygen has been removed by reaction in the palladium catalyst tank 11 is sent to the next step through the conduit 24, but a portion of it is sent to the suction side of the argon compressor 10 via the automatic control valve 14 and the conduit 25. is bypassed into conduit 22 of. In this case, based on the oxygen concentration detected by the oxygen analyzer 1 and the crude argon flow rate detected by the flow meter 2, the calculation unit 8 calculates the required rotation speed of the argon compressor 10 and controls the rotation speed of the Arco 7 compressor 10. By doing so, the discharge flow rate of the argon compressor 10 can be controlled in response to fluctuations in the flow rate of crude argon and the oxygen concentration in the crude argon, and the oxygen concentration at the inlet side of the palladium catalyst tank 11 can be kept constant at all times. can be kept. That is, when the oxygen concentration in the crude argon supplied from the crude argon column increases,
By increasing the rotational speed of the argon compressor 10 and increasing the discharge amount, the crude argon supply amount is controlled to be constant, so the pressure indicating controller 12,
13 and automatic control valve 14, the bypass flow rate of argon from which oxygen has been removed is increased, and the palladium catalyst tank 1
The oxygen concentration on the 1 inlet side is kept constant. Also, when the oxygen concentration in the crude argon decreases, the argon compressor 10
By lowering the rotation speed and reducing the discharge amount, the bypass flow rate of argon from which oxygen has been removed decreases in response to the decrease in the discharge amount, as described above, and the oxygen concentration at the inlet side of the palladium catalyst tank 11 remains constant. be kept. Therefore, even if the oxygen concentration in the crude argon supplied from the crude argon column fluctuates, the oxygen concentration on the inlet side of the palladium catalyst tank 11 can always be kept constant, and the oxygen concentration in the crude argon is low. In this case, the rotational speed of the argon compressor 10 can be lowered to allow a stable reaction to occur, thereby reducing power consumption. The above explanation is
Although we have described the case where the oxygen concentration in the crude argon fluctuates, even when the flow rate of the crude argon supplied from the crude argon column fluctuates, the argon compressor 1
This can be handled by controlling the rotation speed of 0.

That is, when the automatic control valve 4 is operated by the flow rate indicator controller 3 in response to the increase operation and the crude argon supply amount increases by a certain amount, the rotation speed of the argon compressor 10 is increased to increase the discharge amount. In response to the increase in the discharge amount, the pressure indicating controllers 12, 13 and the automatic control valve 14 increase the bypass flow rate of argon from which oxygen has been removed, and the oxygen concentration at the inlet side of the palladium tank 11 is kept constant. . In addition, when the automatic control valve 4 is operated by the flow rate indicator controller 3 for the reduction operation and the amount of crude argon supplied decreases by a certain amount, the rotation speed of the argon compressor 10 is lowered to reduce the discharge amount, thereby reducing the Similarly, as the discharge amount decreases, the bypass flow rate of argon from which oxygen has been removed decreases, and the oxygen concentration on the inlet side of the palladium catalyst tank 11 is kept constant. Therefore, even if the flow rate of crude argon fluctuates, the oxygen concentration on the inlet side of the palladium catalyst tank 11 can always be kept constant. Since the present invention is as described above, it is possible to supply the amount of added hydrogen necessary for the reaction despite fluctuations in the flow rate of crude argon and the oxygen concentration in the crude argon, and the amount of hydrogen added to the palladium catalyst tank can be supplied. The oxygen concentration at the inlet can be kept constant at all times,
When a stable reaction can be carried out and the flow rate of crude argon and the oxygen concentration in the crude argon are low, the rotational speed of the argon compressor is reduced, so power consumption can be reduced.

[Brief explanation of the drawing]

The drawing is a system diagram showing an example of an argon purification apparatus implementing the present invention. 1...Oxygen analyzer, 2...Flowmeter, 3
, 6...Flow rate indicating controller, 4, 7, 14...
Automatic control valve, 5, 8... Arithmetic unit, 9...
・Rotation speed control panel, 10...Argon compressor, 1
1... Palladium catalyst tank, 12, 13...
...Pressure indicating controller, 21-27...Conduit.

Claims (1)

[Claims] 1 Crude argon collected from the crude argon column of the air separation device was compressed with an argon compressor, hydrogen was added, and the mixture was reacted in a palladium catalyst tank to remove the oxygen contained in the crude argon, as well as to remove oxygen. In an argon purifier that bypasses a portion of the argon to the suction side of the argon compressor, the flow rate of crude argon and the oxygen concentration in the crude argon are detected, and the amount of hydrogen required for the reaction is calculated to produce hydrogen. In addition to automatically controlling the supply amount, the rotation speed of the argon compressor is controlled by calculating the required rotation speed of the argon compressor so as to maintain the oxygen concentration at the inlet side of the palladium catalyst tank at a constant concentration suitable for the catalytic reaction. , and a method for controlling an argon purification apparatus, characterized in that the bypass flow rate of the argon from which oxygen has been removed is automatically controlled according to the rotational speed of the argon compressor.