The cleaning of finned heat exchangers in the Swiss wood industry often brings with it special challenges. Under certain circumstances, wood chips can become wedged in the lamellas, so that cleaning can be time-consuming. Puraclean GmbH uses the JetMaster combination unit developed by mycon GmbH for this purpose. The experience gained by Puraclean GmbH during heat exchanger cleaning was incorporated into this development. The JetMaster combination system also removes hard and tough lignin deposits from the sensitive lamella structures without damage. Previously, it was only possible to remove lignin from heat exchanger surfaces by using large quantities of water – usually mixed with chemicals. Here, the JetMaster combination system offers considerable advantages in terms of cleaning effect and water consumption.