Abstract: A continuous mixer system for controlling the saccharide concentration of a sweetened liquid product mixture, which has (i) an undiluted sweetened solution input, (ii) a water input, (iii) a mixer having a product output, (iv) a first positive displacement rotary pump having a speed of rotation for feeding an undiluted sweetened solution through the undiluted sweetened solution input, (v) a second positive displacement rotary pump having a speed of rotation for feeding water through the water input, (vi) a continuous saccharometer for detecting the saccharide concentration of the product mixture discharged through the product output, (vii) a first speed adjuster for adjusting the rotational speed of said first rotary pump, (viii) a second speed adjuster for adjusting the rotational speed of the second rotary pump; and (ix) a controller, wherein a target value SB.sub.x of the saccharide concentration at the product output is preset in the controller and an actual value XB.sub.

Abstract: A rotary pump having a plurality of rotor structures disposed in a pump casing, each structure having a rotor disposed in a casing, a hollow drive shaft each for driving said rotor, a headed bolt disposed within the hollow drive shaft for attaching said rotor to the drive shaft, an internally threaded rotor shaft being attached to the rotor and having said bolt threaded therein, the rotor shaft being disposed within an enlarged diameter hollow end of the hollow drive shaft, and the head of the bolt is disposed at the end of the hollow drive shaft opposite to its end to which the rotor is attached, whereby no rotor attaching means are employed on the face of the rotor opposite to the rotor shaft, and the pump casing has a flat rotor cover over the rotor structures, without any substantial spaces between the rotor cover and the rotors.