Interlock startup issue
Thread Content
There are four conditions for interlock activation: exhaust gas temperature, temperature after the reactor, exhaust gas pressure, and liquid level. As long as one of these conditions is met, the interlock is activated, as shown in the diagram. Thank you; points will be given.
All four conditions must be met to activate the interlock
I think there’s no point at all in posting about these issues – there are pictures and the people who carried out the operations; if you don’t understand those operations, then how can you possibly understand anything?
The diagram shows AND; for the situation you mentioned, OR should be used
In terms of logic, all conditions generally need to be met for interlocking to occur; however, it also depends on how the signals are defined in your actual configuration – whether it’s a logic that leads to shutdown upon interlocking or one that allows operation to continue. So it’s also possible that, as you said, once one requirement is met, it stops
Interlock protection is typically part of a safety-oriented instrument control system; the normal state is 1 (no alarm), while 0 indicates an alarm condition, which triggers the interlock mechanism. The logic in the diagram is that when none of the four conditions trigger an alarm, the output signal is 1, indicating that the normal interlock is in operation. When an alarm occurs in one of them, the signal becomes 0; the output of the RS flip-flop is set to 0, thereby triggering an interlock action.
As can be seen from the diagram, it is a fail-safe design: 1 represents the normal state, while 0 represents the interlock state. Therefore, as long as one of the conditions in the diagram is 0, the interlock will activate. The original poster can try out the interlocking when there are parking opportunities, which will help them understand it better.
And gate: once a condition is met, it triggers activation in sequence!
The logical function block symbols in the image are not clear.
From a process perspective, interlock activation should occur once a certain condition is met.
As soon as either one is met, the interlock is activated!