The forward-reverse section of the PSA hydrogen production unit

Regarding what you said, that \"the lowest pressure can drop to 0.24 MPa\", I understand this to refer to the pressure in the adsorption tower. If the pressure does not meet the process requirements, factors such as the adsorption time (including the time for desorption and flushing), whether there is internal leakage in the programmable control valve, and whether there are faults with the desorption (flushing) control valve need to be considered. The following points can serve as a reference: 1. Is the pressure in the adsorption tower abnormal before desorption? Issues such as internal valve leakage, short equalization time, and faults in the flushing control valve led to high pressure in the adsorption tower before the reverse flow process began, ultimately resulting in a high equilibrium pressure during that process. If there is no abnormality in 1, or the abnormality has been resolved, yet the pressure remains high after normal operation, further analysis is required: 2. Is the pressure in the adsorption tower balanced with that in the normal operation tank? (1) If already balanced: A. The charging tank is too small to meet the pressure requirements for balance. B. The bypass valve is leaking, and process gas continues to be supplied to the bypass tank, resulting in excessively high pressure after flushing. C. The flushing valve is faulty and cannot perform flushing properly. (2) If the pressure is not balanced: A. Please consider whether the setting time is too short? B. Is the forward control regulating valve functioning properly? Is the initial opening too small? C. Is there a fault with the forward control valve? D. Is the pipeline unobstructed? Is there a valve for shutoff? If possible, plot the adsorption pressure, isotherm, and washout curves and post them, to see if anything can be discerned.

The buffer tank is too small, or the pipeline running along it is too small

The reasons for the inability to reduce the pressure under forward discharge are as follows: 1. At the end of forward discharge, the pressure in the adsorption tower should be the same as the pressure in the buffer tank used for forward discharge； If the pressures in the adsorption tower are high and different from each other, it is necessary to first check whether the set regeneration time is appropriate, and whether it can be extended appropriately. 2. Check whether the valve on the pipeline is fully open, if it can be opened to its maximum position, and whether the valve opens slowly or quickly. Is there any flow restriction due to the valve diameter being too small? 3. Is the pipeline for sequential flow too thin? In short, a comprehensive consideration is needed to identify the cause.

Adjust and extend the normal playback time.

1. If the value does not drop to 0.14 once the unit is started up, it could be due to: a. The buffer tank being too small； b. Or the pipeline in series is too small ； c. The playback time is insufficient. 2. The pressure of the device used to drop to a certain level but now does not drop enough; this could be due to: a) leakage in the release valve, with process gas continuously being supplied to the release tank, resulting in excessively high pressure after flushing ； b. The flushing valve is faulty and cannot perform flushing properly.

It might be that the flushing valve isn’t fully open, or the manual valve is opened too slightly, causing internal leakage in the check valve

The pressure remains high after equalizing it even when it should drop

Is this the case for every adsorption tower? It will take time to make adjustments. If this problem occurs with a single tower, it is likely due to the valve (internal leakage)