METHOD AND APPARATUS FOR DEWATERING AND LOOSENING RAW BIOPULP

摘要

2101271 9213709 PCTABS00014 A method for production of dewatered and loosened biopulp, is described wherein precrushed raw biopulp is press fed against a pair of counter-rotating press rolls between which the biopulp is subjected to a pressure whereby it is dewatered and fed into a backpressure vessel maintained at an overpressure which prevents the water pressed out from entering the backpressure vessel and prevents remoistening of the dewatered biopulp, whereafter the biopulp is transferred from the backpressure vessel and subjected to well-known chemical and mechanical treatments for production of powdered fuel, fillers for plastics or pulp for making paper. An apparatus for carrying out said method is also described which comprises a system of feeder pistons (2) for press feeding the biopulp against two profiled press rolls (4, 5), one of which is made of solid metal (5) and the other (4) consists of a number of elastically mounted plates which can move radially in response to a radial load, a backpressure vessel (7) with an overpressure on the exit side of the press rolls, and a compartment feeder (9) for transferring the biopulp from the backpressure vessel.