Bottom Ash Deashing

Bottom Ash Deashing

  • Ensure ash slurry sump level is less than 5 m.
  • Ensure ash water sump level is adequate.
  • Ensure oil converter tank level is adequate (50 %).
  • Check availability of power supply to local control panel.
  • Select the clinker grinder and open corresponding discharge valve from local control panel.
  • Open the hydro ejector inlet valve of selected clinker grinder from OWS.
  • Start BAHP and ensure header pressure of 6.0 kg/cm2.
  • Ensure seal water pressure to clinker grinder is > 1.5 kg/cm2.
  • Open air & oil valves of oil & air converter tank to operate BAH gate.
  • Stop BAH filling.
  • Release EPBs of selected clinker grinder.
  • Observe BAH temperatures during de ashing process
OPERATING PROCEDURE:

  • Check BAHP is running.
  • Start the selected clinker grinder & check running status on local control panel.
  • Flush clinker grinder for 5 minutes in reverse run and for 5 minutes in forward run.
  • Open BAH flushing valves one by one, each for 2 minutes maintaining header pressure, for loosening the compactness of ash/clinkers inside BAH.
  • Open BAH gate of running clinker grinder and check opening status (local indication).
  • Ensure the pressure of 1.0 kg/cm2 at slurry discharge line after discharge valve.
  • Check the bottom ash line warm or cold by touching and slurry flow at
  • ASPH sump.
  • After around 45 minutes, flame will be visible from the view glass at the gate cover, both at front and rear side of BAH.
  • After confirming BAH empty, carry out hopper flushing one by one (first top corners 5 minutes and then bottom corners 5 minutes, maintaining header pressure).
  • Close BAH gate, check closing status of gate by checking gate indication rod position.
  • Flush clinker grinder for 5 minutes.
  • Open BAH filling line valve and start BALP.
  • Open seal trough flushing valve and nozzle flushing valve once in a shift.
  • Open all flushing line valves for 15 minutes for quick filling of BAH.
  • Confirm clear water is coming from bottom ash discharge line.
  • Stop BAHP.

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