GB1366293A - Fluidised bed separators - Google Patents

Abstract

1366293 Fluidised bed separators BERGWERKSVERBAND GmbH 26 Jan 1973 [26 Jan 1972] 4157/73 Heading B2H Particles of granular material are separated according to size and/or density by fluidising a bed of the particles and providing at the bottom of the bed one or more discharge ducts through which a fluid flow of adjustable velocity is arranged so that particles of a required size and/or density may fall through the duct(s) while the remainder of the particles are buoyant in the fluid flow as they pass from the duct(s) through fluidised bed. In Fig. 1, a separator comprises a fluidising chamber 1, a grate 5, a support plate 6, a collecting chamber 7 having an outlet valve 8, a blast box 4 defined between the grate and the support plate and discharge ducts 9 extending through the blast box to provide communication between the chambers 1 and 7. Fluidising gas is introduced as "top gas" 3 through an upper inlet 2 and as "bottom gas" 11 through one or more lower inlets 10. The larger and/or heavier particles fall through the ducts 9 into the collecting chamber 7 against the upward flow of bottom gas which is adjusted according to the size and/or density of particles required to be collected. In Fig. 2, the ducts 9 are provided with collars 12 which support the inserted grate 5. Inserts 13 provided with a bead so that they can rest on top of the ducts are inserted in the ducts so that the grate may be set to a different particle spectrum. The separator may be used in the gasification of coal in a fluidised bed in order to remove heavier or larger fritted mineral ash residue from the bed during the gasification process. It may also be used for the separation of thermally treated reagents from a circulating mixture which also contains solid heat transfer media of different sizes or densities.