GB1230985A

GB1230985A -

Info

Publication number: GB1230985A
Authority: GB
Priority date: 1967-05-26
Filing date: 1967-05-26
Publication date: 1971-05-05

Abstract

1,230,985. Sifting apparatus; centrifugal classifier. E. R. MULLER and M. R. MULLER. 22 May, 1968 [26 May, 1967], No. 24495/67. Headings B2H and B2P. In a sifter for separating foreign matter from pulverulent material, e.g. flour, and of the type in which the material to be sifted is supplied from a hopper 3 to the interior of an upright sifting cylinder 2 located in a receptacle 1 and is impelled centrifugally by blades 5 on a power-driven rotor 4 through a perforate peripheral wall 6 of the cylinder into the receptacle 1, the rotor 4 carries a spreader disc 18 which is spaced by an annular gap 19 from the lower end rim 20 of the hopper 3 and which carries an upwardly and outwardly inclined perpiheral perforate wall 21 terminating above, and leading to, an annular foreign matter trap 23, 24 adjacent the upper end of the wall 21 and surrounding said wall, so that, in operation, the material to be sifted passes through the wall 21 into the cylinder 2 and foreign matter in the material may, depending upon its size, pass up to the wall 21 into the trap 23, 24. The trap is constituted by a pair of overlapping rings 23, 24 which close the upper end of the annular space between the wall 2 and the receptacle 1. The rotor shaft 8 has an axially adjustable extension 11 on which the disc 18 is mounted so that the width of the gap 19 may be varied as desired. The blades 5 are backwardly inclined relative to their direction of rotation A so as to facilitate the passage of foreign matter, still present in the material entering into the cylinder 2, from the latter into the trap. A vane (not shown) fixed to the lower end of the rotor shaft 8 sweeps the clean material from the floor 10 of the receptacle 1 into a discharge chute (not shown). A baffle 26 may be provided on the wall 21 to prevent the material being sifted from passing upwards through the gap 25 into the trap 23, 24. The wall 21 or the flange 22 thereof may carry an arm for sweeping foreign matter from the trap into a discharge chute. A seal 27 closes the space between the hopper 3 and the receptacle 1.