EVAPORATOR START-UP AND BTT CONTROL INSTRUCTIONS

·              Check that the overboard discharge valve has been opened. (MR/064 or MR/061)

·               Open the distillate delivery valve to technical water. (unless otherwise instructed)

·               Set the BTT (Brine Top Temperature – TICSA3°C 9) to 80.0°C.

·               Check the alarm screen for unacknowledged or active alarms.

·               Check that the Steam Booster Heater condensate drain valve is open

·               Press the ‘START-UP/OPERATION’ button.

·               The evaporator will now begin the start sequence phases.

 TICSA3°C 9 – Brine Top Temperature (BTT) Controller

80.0 = BTT Set Point (Input)

77.0 = BTT Set Point (PLC Output)

76.3 = BTT (Actual Temperature)

·         The operator selects the desired BTT (maximum 80°C)

·         The PLC determines the actual set point and ramps up the controller in steps of 1°C per 20 seconds

·               At the ‘Heating Phase’ the steam valve (RV3) will begin to open and heat the re-circulated HT water. The HT water valve (RV8) will remain closed on full recirculation.

·               When steam begins to appear from the Steam Booster Heater condensate drain the valve can be closed.

·               The ‘Heating Phase’ is complete when the BTT reaches 76.0°C.

·               The HT water valve (RV8) begins to open with the BTT reaches 78.0°C.

·               When the evaporator is in the ‘Start Production’ phase the BTT set point can be changed to best suit the steam plant load and the boilers can be appropriately adjusted, but no lower than 72.0°C.