The main purpose of the nitrogen hydrogen proportioning device is to control the flow of hydrogenation or nitrogen addition to achieve the purpose of mixing hydrogen and nitrogen according to a certain proportion. Generally, it is to control the flow of gas with less content. A nitrogen hydrogen proportioning device is mainly composed of nitrogen flowmeter, hydrogen flowmeter, hydrogen analyzer, PID controller, flow regulating valve, pressure gauge, mixing tank, case, etc.
Principle: the hydrogen analyzer measures the hydrogen content in the mixing tank. The hydrogen analyzer converts the measured content into a 4-20mA signal and transmits it to the PID controller. The PID controller converts the signal into a mechanical signal and sends an action command to the flow regulating valve to command the opening of the flow regulating valve. The opening of the flow regulating valve determines the hydrogen content in the mixing tank In order to achieve the purpose of mixing hydrogen and nitrogen according to a certain proportion, constant adjustment is needed.
2、 Device features
1. Hydrogen analyzer: high precision hydrogen analyzer is selected, with accurate measurement, high stability and rapid response. The hydrogen analyzer has 4-20mA signal output.
2. PID controller: Japanese shimanden PID controller is selected, with high control accuracy. It can quickly compare the obtained signal with the set value, and send out instructions quickly to ensure the accuracy and precision of the control. At the same time, rapid reaction can ensure the stability of hydrogen content.
PID control is mainly based on the difference between the content setting value and the content actual value. When the actual value is lower than the set value, the PID control valve will open a large flow, when the actual value is higher than the set value, the PID control valve will close a small flow, so it will continue to reciprocate, and finally achieve balance, that is, the unity of the set value and the actual value.
3. Flow control valve: select high-sensitivity control valve, the valve action range is small, there will be no sudden opening and closing, it can well control the supply of hydrogen, so as to ensure the stability of hydrogen content.
4. The overall box structure of the equipment is convenient for installation and space saving.