Brochure

The white liquor pressure filter is the preferred method for separating white liquor slurry into its primary components of white liquor and
lime mud. This slurry is pumped through the feed valve into the filter vessel where the fluid is forced through a filter. The solid lime mud
cannot pass through the filter and cakes onto the filter itself. When the filter is too caked with lime mud, the recirculation valve opens and
causes the pressure to suddenly drop and create a backflow against the filter. This knocks off the lime mud. This opening and closing of the
discharge valve occurs every five to ten minutes.
This process will see frequent and fast switching and is hard on valves and actuators. Damage includes piston seal wear, bearing wear, and
packing box leaks. Additionally, this slurry is very erosive due to high solids content, and must maintain tight shutoff.
White Liquor Pressure Filter Switching
Fisher
®
Pulp and Paper Solutions | 19
Recovery
Product Solutions
n EXTENDED SERVICE LIFE Heavy duty valve bearings and PTFE packing extend service life capabilities.
n LOST MOTION Minimal lost motion with taper pin/disk connection and splined shaft.
n FLOW CAPACITY Contoured disk increases ow capacity and reduces operating torque.
n EMISSION CONTROL Superior sealing and ENVIRO-SEAL packing reduces emissions.
n EASY INSTALLATION Centering holes and line ange bolts reduces valve centering issues for easy installation.
Fisher 8532 High Performance Butterfly Valve, 1061 actuator, and FIELDVUE DVC6200
Recovery