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 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.
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.
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.