GB595261A - Improvements in or relating to mixing machines - Google Patents

Abstract

<PICT:0595261/III/1> <PICT:0595261/III/2> <PICT:0595261/III/3> A machine for mixing and kneading plastic masses and for the emulsification of viscous or gel-like substances in aqueous media comprises a closed treating chamber and at least one mixing member therein adapted for rotation relatively thereto and having teeth co-operating with teeth on the inner surface of the chamber, or on a further mixing member, the shape and arrangement of the teeth being such that the bulk of the material under treatment cannot pass through the area in which the co-operating teeth are at a minimum distance apart, so that the material is diverted axially along the length of the chamber. The shape of the teeth is also such that each of the surfaces within the chamber to which the material under treatment will tend to adhere is cleaned during the treatment by wiping by another surface. The treating chamber may have a shape equivalent to two parallel intersecting cylinders within each of which are disposed two independent coaxially mounted toothed rotors which can be driven in opposite directions. The treating chamber 18, Fig. 6, comprises members 10, 11 secured by vertical bolts, and mounted therein are two pairs of oppositely driven intermeshing rotors a, b, and x, y, Fig. 1. The rotors are of epicycloidal or hypocycloidal cross section and have a length inversely proportional to their rate of rotation. Material is fed into the chamber through an opening 26 normally closed by a plug 26a, is carried downwards around the rotor b to be kneaded in the bite between the rotors a, b, and is circulated around and upwardly through the bite between the rotors x, y to be returned for recirculation to the rotors a, b. The rotors x, y are shorter than the rotors a, b and are driven at a proportionately higher speed. The relative rotation of the pairs of rotors may be reversed during the treatment by the adjustment of crossed and open belts on a fast pulley 32, Fig. 3, and two loose pulleys 33 on a driving shaft 31. The latter drives the rotors a, b and their associated shafts 19, 20 through spur wheels 34, 35 and pinions 36. Shafts 21, 22, carrying the rotors x, y, are driven through spur wheels 37, 38, and pinions 39. When the chamber 18 is to be emptied, the shaft 31 is pushed horizontally to disengage spur wheels 34, 35, while retaining engagement between spur wheels 37, 38. Gear wheels 40, 41 on a lay shaft 42 are then brought into engagement with driving pinions 39, 36, respectively, thus reversing the direction of rotation of the rotors a, b. The material is then discharged through an orifice 44, normally closed by a plug 45. Tubular channels in the members 10, 11 from passages for a cooling medium. In an alternative construction the treating chamber contains only one pair of intermeshing rotors which are less long than the chamber and are reciprocated axially. The rotor teeth are helical and preferably of epicycloidal and hypocycloidal form, and their direction of rotation can be reversed in synchronism with the reversal of the axial stroke. In a further alternative construction the treating chamber is rotatable and consists of a cylinder toothed on its inner periphery. An inner rotor with a small number of teeth engages the teeth of the chamber and is rotated and axially reciprocated. A crescent shaped abutment fills the space not covered by the path of the teeth.