The  candle filter (type CF) is a fully automatic, batch-operated filter whose filter elements are arranged vertically inside a pressure vessel. It is used for clarifying liquids with a low solids content. The candle filter is a compact unit that allows for high throughput rates, dry cake discharge and a wide range of cake treatment options.

The suspension is fed into the pressure vessel and continuously pumped until the required cake thickness has been reached. The filter cake is formed on the outside of each filter candle. The filtrate is discharged from the inside of the candles through immersion pipes. After filtration, the filter cake can be washed, reslurried or dried. Finally, the cake is lifted by a blast of compressed air and discharged.

BHS also provides complete candle filter installations including fittings, instrumentation, piping, pumps, tanks, steel structures, and control systems. The plants have a modular design for easy transport and assembly