The Powderstream system is suitable for the direct suction of powders and mixing of powders into liquids without the need for a vacuum rated process vessel. The liquid passing through the Powderstream system is deflected in a narrowing cross-section so that a partial vacuum is formed. This negative pressure causes powder to be sucked in from a hopper or a lance. Consequently, powder is then finely dispersed in a liquid, eliminating clumping and fisheyes.