GB1268231A - An improved apparatus for continuously fermenting processed tea leaf - Google Patents

Abstract

1,268,231. Fermenting tea. TEA RESEARCH ASSOCIATION. 18 June, 1969 [28 June, 1968], No. 30911/69. Heading A2B. An apparatus for the continuous fermentation of processed tea leaves comprises a plurality of abutting trays, each with a perforated bottom and two upstanding side plates, which define a continuous leaf carrying surface which extends and travels in a generally straight upper path between two ends, means at each end for transferring the trays between the upper path and a lower return path, and an air chamber, provided at opposite ends with means for preventing ingress or exit of air so as to constitute a closed air flow circuit, and enclosing a substantial part of the upper path, the air flow arrangement being such that substantially half the chamber is kept under suction whilst the other half is kept under compression, and means inside the air chamber to ensure that the flow of air is positively directed upwards or downwards through the leaf-carrying surface enclosed by the air chamber. Fig. 1 shows a suitable embodiment, wherein trays 1 having perforated bottoms and upstanding side plates 2 are drawn by endless chains 3 along upper and lower paths. Tea is fed from hopper 16 onto the trays, which pass into air chamber 6. Swinging baffles 7 and 8 seal off the chamber from the outside, and intermediate baffles 11 divide the air chamber into compression and suction zones. The lower part of the chamber from return air duct 10. A second endless chain drive 12, fitted with laths 13 to seal off the perforated trays for start up and shut-down of the apparatus, may be driven synchronously with the main drive. Vibrating shaft 21 is provided to assist in emptying the tea from the trays.