Sodium bicarbonate filters by eimco-k.C.P. Are specially used in the production of soda ash to dewater as low as possible moisture content of the sodium bi-carbonate filter cake and to wash the cake free of ammonium chloride. Special features of the filter are that special back-wash feature to prevent blinding of filter media, special heavy-duty construction throughout, special streamlined drainage construction with extra large valve to insure maximum removal of wash liquor and low cake moisture, special wash system to provide uniform wash-water distribution and additional cake compression to remove the moisture from cake.