CWA23L vacuum evaporator with working capacity of 400 dm3 was constructed according to customer’s special requirements and guidelines. The device was made in close cooperation with our client, from the design stage to the final acceptance and testing. The basic version of the device has been extended, e.g. a mobile tank for loose raw materials that facilitates the operation of the device, a precise water dosing system, a special drain valve, a gear pump of our production and an insulated buffer tank.