Solving two problems with one solution – New RTO system from Dürr with an evaporation tower

Stuttgart, June 20, 2008 – Purification of exhaust gases via thermal oxidation is all in a day’s work for an RTO. However, a separate unit has always been required to evaporate any remaining aqueous process residues. With the introduction of Ecopure® EVA, a completely new evaporation tower design, Dürr Environmental and Energy Systems (EES) can now combine both processes – and include an auto-thermal mode that provides high energy efficiency.

The Ecopure® RTO system with an added evaporation tower proves to be the ideal solution in all branches of industry, where production exhaust gases and oil free waste water containing organic hydrocarbons occur. When the disposal of exhaust gases and liquid residues is combined in a single treatment system, energy obtained from the hydrocarbons in the exhaust air is used to evaporate the water.

In previous decades, small quantities of aqueous residues have been disposed of in Regenerative Thermal Oxidizers (RTOs) supplied by Dürr EES. But evaporation of larger volumes of waste water was not possible in the RTO systems currently on the market. Through integration of the newly developed evaporation tower Ecopure® EVA, Dürr is now able to dispose of two different waste streams simultaneously, within one plant – and needs to draw on virtually no primary energy resources to do so.

The height of the evaporation tower is selected to suit the evaporation path for individual contaminants. The tower includes a single central lance with an appropriate number of dual material nozzle heads – as an alternative option, this single lance can be replaced by several lances. Additional equipment is provided to ensure that the waste liquid is completely evaporated. 

The evaporation tower is not designed to bring about any chemical reaction, it simply evaporates the medium. However specific cases need to be assessed separately so that operating parameters are set to suit individual circumstances. Consideration of criteria such as hydrocarbon content, for example, is just as important in terms of configuration as viscosity or any preceding chemical reactions that may lead to the production of intermediate products.   

Combining the disposal of waste gases and waste water in one plant not only reduces the cost of investment; by virtually eliminating the use of primary energy sources, it also lowers operating costs.