Issues with fluctuation in the gas regulating valve for PSA in dry gas hydrogen production
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Since the purge gas control valve regulates the backpressure, which in turn controls the amount of purge gas that enters the converter, increasing the set value for the backpressure causes severe fluctuations in the operation of the control valve. This leads to fluctuations in the amount of purge gas entering the converter, and as a result, fluctuations in the temperature of the furnace. I would like to ask the experienced professionals here why this happens. Currently, fluctuations occur whenever the backpressure set value exceeds 0.016. How can this issue be resolved? Thank you to all the experienced professionals in the chemical industry
Contact the instrumentation team to check whether there is a problem with the positioner of the analysis gas valve! Is the valve position fluctuating a bit? Go to the site to check!
Manually open the control valve fully and then switch to automatic mode; adjust the proportional and integral settings accordingly
Such problems arise due to fluctuations in the PSA off-gas as it is released during the desorption process in the adsorption tower. This can be addressed by adjusting the flow rate of the off-gas entering the conversion furnace; instead of controlling the pressure of the off-gas, flow control should be used. The flow meter needs to be installed near the conversion furnace, while the control valve should be placed on the side of the PSA desorption gas tank. The pipe section between the control valve and the flow meter can serve as a buffer, and a flow-limiting orifice plate can be added after the control valve. This requires design calculations, and the selection of the control valve is also important.