The latest Renzmann innovation: Rotomax-W unit for the evaporation of aqueous-alkaline washing and rinsing agents.

The condensed clean distillate is reintroduced into the rinsing water/washing agent circuit so that there is no wastewater. Unlike the used rinsing water and washing agent, the heavily reduced and concentrated residue is disposed of as hazardous waste. Thanks to the distillation with the pre-evaporator, which takes place in two steps, the energy required per litre of evaporated water is cut by half. About half of the medium is evaporated under normal pressure in the pre-evaporator. The hot steam (100 °C/212 °F) generated during this process contains the energy supplied in the pre-evaporator and is piped into the heating floor of the distillation unit. After being slightly concentrated in the pre-evaporator, the medium is sucked into the distillation boiler, in which a vacuum has been created. Due to the vacuum, the boiling temperature in the boiler is reduced to <60 °C (140 °F). This results in a temperature difference of >40°C (104 °F) between the boiler contents and the steam from the pre-evaporator; consequently, the steam condenses in the heating floor and transfers its energy to the boiler contents.

The medium in the boiler is concentrated until more than 95% of its original volume has evaporated. The distillate from the pre-evaporator that condenses in the heating floor is sucked into the condenser of the distillation unit, where it joins the condensed vapours from the boiler. The distillate cools slightly in the condenser, runs into the vacuum unit and from there into a separate clean solvent container.

The loss of liquid in the pre-evaporator (due to evaporation and to liquid being sucked into the distillation boiler) is compensated for by automatic refilling.