WIKA: High water quality for demanding processes in measurement engineering
WIKA is a global leader in the field of pressure and temperature measurement. In the production of measuring instruments, the delicate components are required to provide ever-increasing precision, which also means ever more demanding requirements on the cleaning systems and the related water treatment systems. For the new production facilities, WIKA invested in a new ultrasound cleaning system. The system with seven baths needs to be fed with conditioned water. The aim is to ensure consistently high water quality to supply all of the withdrawal points with a recirculation loop and a buffer tank. For rinsing in the structuring and lithography tools, pure water at a temperature of 60 °C is needed. Before discharging the wastewater, the heat needs to be recovered using a heat exchanger. This heat can then be used to preheat the fresh water. In addition to a good energy balance, prevention of contamination with germs ‒ without constant use of chemicals ‒ was also required.
Following comprehensive consultation, a water treatment system was devised that supplies the withdrawal points of the cleaning system as well as other consumers. To avoid introducing particles into the water treatment system during the production process, the system was completely built in a clean room at EnviroFALK’s production plant.
In addition to demineralisation by reverse osmosis and electrodeionisation, UV light and ultrafiltration ensure low bacterial and endotoxin contamination. To make certain that the requirements are fulfilled in the long term, the system is made of IR-welded PP upstream of the reverse osmosis unit and of PVDF, sealed by bead and crevice free (BCF) welding, on the permeate side.
- Conductivity <= 0.0565 µS/cm
- Silicate content < 100 ppb
- TOC in the lower ppb range
- Particulates < 0.2 µm
- Peak withdrawal: 700 litres of pure water in 10-minute intervals