What systems are set up to take care of a low flow situation? I assume for most people the fuel gas trips and the emergency steam enters. Is there any other part of a low flow shutdown? What do you do to prevent putting cold feed to the drum? Do you do anything different if it is a situation where you expect feed back almost immediately such as a charge pump cavitation?
1. Fuel gas trip, and Velocity Steam
It is known that emergency steam means the steam injected into the radiant box in case of a fire or explosive atmosphere.
2. It is recommended to have one flow control valve per flow pass in coker heaters, just to keep the bulk temperature of all passes to a similar value. It is called “COIL BALANCE”. Of course, flow, pressure and temperature are key variables.
3. Increment the velocity steam if a problem of low flow occurs.