Cold Starting or Warming Up or Initial Starting Of Boiler
Cold starting means starting off the boiler from a state of comparatively lower temperature and pressure than normal working values. In other way we can say that cold starting is starting the boiler for the first time in its lifespan. It is ,indeed a very critical operation because the variation in temperature and pressure may lead to thermal stress resulting in cracks of tubes. Below you can find the step wise procedure of cold starting
> Switch on the breaker of the boiler in control panel.
> Make sure that air- vent is open and steam- stop valve is closed
> Line up the feed -water system and run the boiler feed water pump,manually, until the low level alarm goes or water level becomes visible in the gauge glass. This is because it is not possible to start the boiler if there is a low water level alarm persistence
> Run the FD (Forced draft) fan and purge the furnace
> Line up the fuel -oil valves and start booster pumps. (If the fuel is HFO turn on the electric heater and wait for the temperature come to required range).
> Manually fire the boiler in short intervals, otherwise it leads to thermal stress.
> When steam comes out of the air vent , shut the vent, slowly raise the pressure up to normal working pressure.
> Open the steam- stop valve slowly
> Put the boiler -feed pumps in auto mode, make sure that it is cut in and cut off automatically.
Stopping Of Boiler
Boiler needs to be stopped for various reasons like maintenance, survey etc.
> Turn the switch in to stop position, boiler will automatically stop after post purging. (If it’s required ,purge the furnace manually)
> Stop the feed water pumps and fuel oil circulating pumps. If there is heater for fuel oil, stop it.
> Close the steam stop valve when the pressure comes down to 1.5 - 2 bars
> Let the steam pressure come down further, near to atmospheric pressure. open the air vent to prevent vacuum formation which leads to the damage of the tubes.
> Water can be drained slowly if required
You Can Answer Following Questions
> Explain Boiler starting procedure or boiler cold starting procedure
> Explain Boiler stopping Procedure
> Use of air -vent provided in boiler
> How do you prevent vacuum generating inside the boiler while stopping the boiler?