Urgent! Urgent! Urgent! ! There are reports on-site of steam over-temperature issues; let’s see what can be done, any good suggestions?
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During the resin processing phase (the cycle heating stage), there was a problem with the malfunctioning regulation of the steam valve (the automatic control system indicated that the switch was in the correct position, but in reality the electric steam valve failed to function properly). Manual adjustment on site revealed that this electric valve could only be opened and not closed, which caused the desorbent to continue heating up for over 2 hours; its temperature rose above 80°C, resulting in swelling and rupture of the desorption fluid pipeline. How should this be designed to prevent such situations from occurring, and what should be done once such a problem arises? I hope the experts will not hesitate to offer their guidance!
Valve failures are quite common; this is clearly due to the control system failing to monitor the temperature properly. When a high temperature is detected, inspections should be carried out earlier. Moreover, critical parameters like these should be equipped with alarms. These are my personal opinions; please point out any mistakes.
In terms of monitoring, the flow rate should decrease after closing the valve; if there is no change in the flow rate, it is necessary to go to the site for inspection. Regarding instruments, large enterprises with a high degree of automation use two control valves in series
It is recommended to install a temperature alarm in the container used in the resin processing process, and to place an emergency shut-off valve before the steam control valve; the temperature alarm and the emergency shut-off valve should be interlocked. When the set alarm temperature is reached, if the temperature rises by another 0.5 or 1.0°C, the emergency shut-off valve closes automatically, stopping the heating of the resin process. Inspect the steam control valve. For your reference
Change the valve – wasn’t it said that it should only be opened and not closed?
Control valves cannot be used as stop valves, as they are prone to leakage. It is recommended to install an electric ball valve in front of the control valve
For those with sufficient funds: electric control valve after the automatic shut-off valve on the main pipeline, and electric control valve for the bypass； If there’s no money, install the manual valve first and the control valve later.
The previous set of steam temperature and pressure reduction devices should work fine; is the secondary steam overheated?
First, cut off the steam to prevent further overheating; it is recommended to install a valve assembly to facilitate maintenance