Afterwards, it was known that the nitrogen pressure dropped suddenly at that time, and the power should be cut off and heated in time. I saw the nitrogen pressure wasn't fast enough to close the valve. Close the first also dehydrogenation interrupt, then close the nitrogen and anti-air valves. If nitrogen or hydrogen quality issues, you must add hydrogen to disconnect the power outage, turn off the nitrogen, turn off the blowdown. When the nitrogen valve is first opened, the exhaust valve is opened after (also the first replacement pipe) the hydrogen valve. Inert gas and flammable gas, start and stop are not the same, must consider safety.

Liquid nitrogen cooled to 50 degrees, all valves, leakage test, electric heating outlet valve opened (hello, nitrogen and hydrogen quality and normal pressure, then carefully check no leakage, valve switch is correct,) nitrogen replacement pipeline, transfer to 300 square logistics, close the exhaust valve reactor, open the upper and lower valves, open the exhaust valve, blow the hydrogen pipeline to connect the hose, The hydrogen main valve opens until about 7 to 10 square flows. Electric heating preheats directly to the original opening valve temperature.

Remember the exothermic reaction of hydrogenation temperature, activate the last round of the first stage, remove hydrogen, the temperature at the top of the reactor drops, and rises after connection. This seems to be flexible, not rigid dogma. Because different stages, the same problem, the symptoms are not the same, the treatment method is also different, can not be wrong. For safety's sake, the second is assurance