Hoeflon (Barneveld): high-end pretreatment with polypropylene immersion baths

At Hoeflon in Barneveld, ESTEE built a high-end pretreatment with a line of polypropylene immersion baths, followed by a direct gas-fired A-cap oven. The complete installation is controlled through UNICoater, ESTEE’s own control and data platform.

Immersion baths in polypropylene

The baths are built in 15 mm thick polypropylene, with a sloping bottom, and sit in a pit. Polypropylene is chemically inert and insulates much better than stainless steel, so the heated baths retain their heat better. Vertical polypropylene pumps provide the agitation in the baths.

Heating, demin water and filtration

A 255 kW high-efficiency boiler heats the baths through heat exchangers. A dedicated reverse osmosis unit supplies the demin water for the rinse baths, and the baths are filtered continuously. Collectors along the edge of the baths extract the vapours through individual droplet separators.

A-cap oven

After pretreatment, the parts pass through a direct gas-fired A-cap oven, 12.7 m long and 10.6 m wide. The oven runs at 200 °C on average and processes 3,000 kg of steel per hour: 6 beams of 500 kg.

Controlled through UNICoater

Bath line and oven are connected to UNICoater and operated through a Siemens touch screen. Conductivity meters and dosing pumps control the chemical supply automatically, and water, chemical and energy consumption is measured continuously, so deviations are spotted quickly.