Chemical and API
ZLD: MEE + ATFD + Stripper
Zero Liquid Discharge Systems help plants to conserve water and minimise effluent discharge. The system, comprising a stripping column, Multiple Effect Evaporator and Agitated Thin Film Dryer, removes dissolved and suspended solids from wastewater.
The resulting water stream is reused and the solid waste stream disposed. ZLDs consume about 40% of total plant steam. Besides high operating costs, high moisture in the solid stream and not being able to operate the ZLD at design capacity are also issues prevalent across plants.
Our Solution:
The holistic solution from Forbes Marshall encompasses
Supply steam pressure reduction to 1-1.5barg and use of ATFD flash steam to operate the stripping column instead of live steam
Monitoring of feed flow, feed and outlet concentration, steam pressure, temperature and flow, feed transfer between effects, effect pressures and temperatures and cooling water temperatures. Steam is controlled based on these parameters.
Maintaining vapour balance (vapour control valve).
Evacuation of non-condensables (AV)
Complete condensate evacuation
Live steam to the preheater to control variations in feed temperature
Vapour loss prevention (trap between 1st and 2nd effect) and condensate evacuation (SOPTs for subsequent stages)
100% condensate and flash steam recovery
Optimised pressure control and individual trapping for each zone (ATFD).
