Waste water evaporators. Consulting. Chemical Waste Management.

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 controlled to between 50-60°C. Even foaming liquids do not usually present problems.

A waste oil fired unit has recently been commissioned 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 waste fired waste water evaporator has been commissioned. Hot combustion gases are mixed with ambient air and drawn into the evaporator. Ash is scrubbed out and ends up in evaporator concentrate.
Hot gases from aqueous waste incinerators can also be used as energy sources for evaporation. Evaporator will also function as a scrubber. Waste heat from gas or liquid fuel powered electricity generators is ideal for these evaporators. Economics are very attractive.

Cyclonic wood burners can be configured to operate as "lean waste" thermal oxidizers. The hot gases are then used as energy source for evaporation of water. Evaporator unit also functions as a scrubber. The combination of "lean waste" oxidation and water evaporation is very economical.
Picture shows combustion chamber for a wood waste fired evaporator having an evaporation rate of up to 15 L/min.
This is a waste water evaporator that uses renewable energy.
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-DELCD 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: (M) +1-519-581-7350 •
Other technologies are available from A.B.E. Environmental Technologies, Inc.