Pulp washer mist eliminator and foam remover system

A method for separating liquids existing in a gas stream in a counter-current pulp washer of the type having a suction box comprising a receptacle with a reservoir of a pulping liquor disposed therein that is used to supply upstream showerheads for displacement washing pulp, said method comprising:

• providing a gas/liquid separator proximate to said suction box receptacle, said gas/liquid separator having a housing disposed above said liquid level, said housing having a wall extending around a generally longitudinally extending substantially vertical centerline with a lower end and an upper end disposed at opposing ends of said housing;
• said upper end adapted to provide a gas outlet in flow communication with a gas vacuum source;
• a separation chamber having a chamber inlet in flow communication with a gas/liquid inlet to said gas/liquid separator from said suction box receptacle and a chamber outlet in flow communication with said gas outlet, said separation chamber further having a chamber wall substantially aligned with said centerline and a flow director providing flow entering said separation chamber in a direction not parallel to said vertical centerline;
• a separated liquid drain having a drain tube extending from said housing directly to a drain tube end outside said suction box;
• drawing a suction from said gas vacuum source to draw a mixture of gas and liquid particles from said suction box through said separation chamber inlet in a flow-wise direction not aligned with said centerline such that entrained particles have a velocity and a momentum causing impingement on said chamber wall where the particles coalesce into droplets of separated liquid that travel downward by the force of gravity towards said separated liquid drain;
• and
• draining separated liquid through said drain tube outside said receptacle such that separated liquid does not re-enter the pulping liquor within the receptacle sump and such that a gas vacuum within said housing is insufficient to draw separated liquid upward above said separated liquid drain.

A pulp washer having a horizontally disposed endless wire with drive rolls for moving said wire in an upstream to downstream direction, a headbox for feeding a pulp suspension containing dissolved solids to an upstream location on said wire, a suction box having a receptacle underlying said wire, said receptacle having a sump for holding pulping liquor received into said suction box during operation and a sump drain, wherein during operation said pulping liquor has a pulping liquor level within the receptacle, said pulp washer further having liquid showerheads positioned over said wire for directing in operation a liquid shower over said wire and said pulp to wash dissolved solids from said pulp whereby in operation at least some of said liquid with dissolved solids will drain into said suction box receptacle as said pulping liquor, said pulp washer further comprising:

• a gas/liquid separator positioned proximate said suction box and having a gas/liquid inlet located in flow communication with said suction box above said pulping liquor level and a gas outlet in flow communication with a gas vacuum source such that in operation said gas vacuum source pulls gas through said gas/liquid separator from said suction box providing a suction under said wire to augment flow of liquid through said wire to said suction box receptacle with gas from above said wire at a higher pressure than gas below said wire;
• said gas/liquid separator further comprising:
• a housing having a wall extending around a generally longitudinally extending substantially vertical centerline with a lower end and an upper end disposed at opposing ends of said housing, said lower end having a separated liquid drain with a drain tube extending from said housing directly to a drain tube end outside said suction box such that separated liquid does not re-enter the pulping liquor within the receptacle sump and said upper end adapted to provide said gas outlet;
• and
• a separation chamber intermediate said lower end and said upper end having a chamber wall substantially aligned with said housing centerline and internal to said housing wall, a chamber inlet formed in said housing wall with a flow passage having a centerline oriented substantially transverse to and offset from said vertical centerline, said flow passage extending outward from said chamber inlet to said gas/liquid inlet.