Process water distillation plant and method for operating a process water distillation plant

A method of operating a process water distillation system comprising:

• an evaporator,
• a condenser,
• a compressor configured to generate a desired pressure in at least a region of the process water distillation system and to convey steam from the evaporator to the condenser during operation of the process water distillation system, and
• an inert gas source configured to supply inert gas to the process water distillation system,
• wherein a control device controls the supply of inert gas from the inert gas source to the process water distillation system in such a way that, at least in certain operating phases of the process water distillation system, an oxygen concentration in the process water distillation system does not exceed a permissible maximum value, and
• wherein the process water distillation system further comprises an oxygen sensor configured to transmit signals characteristic of an oxygen concentration in the process water distillation system to the control device, wherein the control device controls the supply of inert gas from the inert gas source to the process water distillation system in dependence on the signals transmitted by the oxygen sensor,
• wherein the control device controls the operation of the process water distillation system in such a way that
• in a supply step, inert gas is supplied from the inert gas source to the process water distillation system until a first pressure above atmospheric pressure is reached in the process water distillation system,
• subsequently, in a pressure reduction step, the pressure in the process water distillation system is reduced to a second pressure below the first pressure, and
• the supply step and the pressure reduction step are repeated until the oxygen concentration in the process water distillation system has reached the permissible maximum value.