Abstract: In a powder dispenser comprising a container in which powder is supported on a screen, water under pressure for forming a concentrated solution or dispersion with the powder is introduced into a tube beneath the screen. The tube contains a plurality of apertures along its length and is rotatably mounted substantially mid-length so that an upwardly directed spray of water is directed from the tube through the screen onto the bottom layers of powder thereon with a sprinkler effect as the tube is rotated. Tube rotation is preferably imparted automatically under the reaction forces of the water leaving the apertures which are offset from the vertical in opposite senses on each side of the rotary axis.

Abstract: To permit two different fluent media to be pumped independently of each other in one and the same peristaltic pump, a single reversible motor 3 is connected to at least two rotors 7,8 respectively passing over an associated separate resiliently compressible tube 12, 13, a first of said rotors 7, being effective to compress its associated tube 12 only when the motor 3 is turning in one direction 34 and a second of said rotors 8 being effective to compress its associated tube 13 only when the motor 3 is turning in the opposite direction.