Disposing waste water from cleaning process in a closed loop
An evaporator disposes waste water instead of water treatment system in a regulated installation site.


Koyo Heat Treatment Co., Ltd., a heat treatment specialist for bearing and other auto parts, was looking for a substitute for water treatment system at their new factory since the release of waste water was not permitted by the regulations. They finally decided to install an evaporator to shorten the lead time before starting up the factory.


We could not find an evaporator that would meet the requirements of small energy and installation spaces, closed-loop system and short delivery time.
Most important point to select an evaporator was that the condensate from the evaporator would be recycled, not containing the surfactant or other chemicals to wash out the cooling oil for heat treatment process.


It was confirmed in the test with the heat pump type evaporator that the waste water could be concentrated 10 times and the condensate could be recycled with less n-hexane extract, BOD and COD figures than the regulated ones.


  1. By evaporating the waste water, the requirements of small energy and installation spaces, and closed-loop system were satisfied.
  2. We could build a new factory for cutting-edge auto parts in a short time.
  3. Since the waste water was evaporated, other chemicals than the existing ones could be used for cleaning process, which might improve the quality of parts.