Abstract: An extensional flow mixer especially for viscous liquids has a housing with an end inlet connectable to a pressurized source of the liquids, and an outlet at an opposite end of the housing. A mandrel located in the cavity has protrusions with sloping side surfaces, the outer edges of which cooperate with the internal surface of the cavity to divide the cavity into a series of chambers separated by slits, such that liquid passes successively through all the chambers and slits in moving from the inlet to the outlet. The slits have cross-sectional areas which decrease in the liquid flow direction. The mandrel sides have helical grooves forming passageways with the housing wall which allow liquid to be distributed evenly around the edges of the mandrel to the inlet end or upstream chamber. The mandrel may rotate to provide additional shear mixing.

Abstract: An extension flow mixer especially for viscous liquids has a housing (10) with an end inlet (12a, 14a) connectable to a pressurized source of the liquid, and an outlet (119) at an opposite end of the housing (10). A mandrel (30) located in the cavity has protrusions (20′, 32′) with sloping side surface, the outer edges of which cooperate with the internal surface (114a) of the cavity to divide the cavity into a series of chambers separated by slits, such that liquid passes successively through all the chambers and slits in moving from the inlet (12a, 14a) to the outlet (119). The slits have cross-sectional areas which decrease in the liquid flow direction. The mandrel (30) sides have helical grooves (134) forming passageways with the housing wall (114a) which allow liquid to be distributed evenly around the edges of the mandrel (30) to the inlet end or upstream chamber. The mandrel (30) may rotate to provide additional shear mixing.