Abstract: A disc filter and method of operating same is provided in which a liquid jet is intermittently used to detach pulp cake from the disc filter. In operation, mechanical or electrical means actuate a nozzle to spray pressurized fluid at a portion of the boundary between the surface of each disc filter segment and its associated pulp cake. The nozzle is actuated to begin spraying as respective segments move into register with the nozzle and are cause to discontinue spraying prior to moving out of register when the loosened pulp cake falls from the segments by gravity. the improved control of pulp cake removal reduces use of washing fluid and results in improved pulp cake consistency.