Pressure filter with a flow distributor and a method for washing the pressure filter

A method for a pressure filter including a filter container, a substantially horizontal plate, filtering elements hanging from the plate and filtrate container above the horizontal plate, the method comprising:

• pumping a liquor suspension generated by a chemical pulp mill into the filter container;
• passing filtrate liquor from the liquor suspension through porous tubular walls of each of the filtering elements and into an interior chamber in each of the filtering elements;
• moving the filtrate liquor from the interior chambers of the filtering elements into the filtrate container and out through a discharge of the filtrate container;
• caking a precipitate on an outer surface of the tubular walls as the filtrate liquor passes through the walls;
• discharging a thickened liquor suspension from a discharge of the filter container;
• periodically washing the filtering elements by ceasing the pumping of the liquor suspension into the filter container and injecting a wash liquid into the filtrate container to cause the wash liquid to flow from the filtrate container down into the interior chamber of each of the filter elements and through the porous tubular walls to dislodge the cake of precipitate the outer surface of the tubular walls, and
• distributing the flow wash liquid in each of the interior chambers by a flow distributor positioned in each of the interior chambers at an elevation above a mid-elevation of the interior chamber.