Aqueous Waste Evaporators

Evaporation of water from industrial wastes presents special problems: Corrosion, scaling and emissions. TAF Industrial Consulting has designed an evaporator that does not use metal heat transfer surfaces. Heat transfer is from hot or warm gas to water. This is ideal when hot gases from biomass combustion are used as energy source. Final temperature is controled to between 50-60°C. Even foaming liquids do not usually present problems.

A waste oil fired unit has recently been comissioned in Ontario, Canada. Comprehensive stack testing has proven that the emissions are not even close to any regulatory limits. Stable, continuous operating conditions are rapidly established. Another evaporator is using waste heat from an annealing furnace. This is the ultimate in energy efficiency. A third unit located in eastern Ontario is natural gas fired and includes partial energy recovery. Another first: A wood fired waste water evaporator has been ordered. Hot combustion gases are mixed with ambient air and drawn into the evaporator. Ash is scrubbed out and ends up in evaporator concentrate.
Another variation is in the design stage; partial energy recovery by condensing evaporated water and second stage air heating using boiler stack gases. Condensed water is recovered and used for boiler feed. Variable operating cost is insignificant.
Feed quality control is very simple: Use SPME-GC/FID for VOC type chemicals and a refractometer for dissolved solids. Adjust pH to minimize corrosion and volatilization of certain chemicals. Set control parameters once, and let the modulating burner do the rest. No special skills are required to operate the evaporator.
The key features of the TAF evaporators are simplicity and energy efficiency. Continuous washing action minimizes need for cleaning. Evaporators operate in continuous, not batch mode. Contents of larger tanks can be recirculated through the evaporator. Stainless steel construction of evaporator part is standard. Polymeric corrosion resistant materials can be used when required. The design can be scaled to any required capacity.

TAF Industrial Consulting
629 Mill Park Drive
KITCHENER ON N2P 1V4 CANADA
Tel: 1-519-581-7350 • Fax: 1-519-489-2772

Other technologies are available from A.B.E. Environmental Technologies, Inc.