In our New Zealand Patent Specification No. 229080 (European equivalent Application No. 90304922.9 and Australian equivalent Application No. 55013/90) there is disclosed a process of preparing a hydrolysed lignocellulosic material, the full content of which is hereby incorporated by way of reference.
The present invention could have application in such a process/system between different pressure situations or in improved versions thereof. Indeed, the present invention can provide an alternative in many situations to the very expensive and high upkeep "Bauer valves" (Sprout-Bauer inlet rotary valves manufactured and sold by Andritz Sprout-Bauer Australia Pty. Limited of 22 Princes Highway, Dandenong, Victoria 3175, Australia), or any such other rotary devices or devices that do not involve rotary chambers and which are used by default in the absence of an economic way of feeding materials from one vessel to another.