Patent GB-538456-A (GB)
Title: Process and apparatus for extracting and cleaning long vegetable fibres from vegetable matter such as the leaf sheaths of the abaca plant
IPC: D01B9/00
Filed: 1940-03-26
Abstract: 538,456. Obtaining fibres from abaca plants &c. UNITED FRUIT CO. March 26, 1940, No. 5441. Convention date, April 12, 1939. [Class 120 (i)] Cleaned fibres are obtained from the leaf sheaths of abaca and similar plants by anchoring a part of the sheath and submitting it to the impact of a thin wall of liquid extending across the sheath and having a velocity head at the point of impact in excess of 500lbs. per square inch while supporting the portion of the sheath being operated upon against a supporting surface or baffle and subjecting it to an hydraulic scraping action by moving the thin wall of liquid in a direction lengthwise of the supported sheath and away, from the anchoring point thereof. As shown the individual leaf sheaths after being flattened are laid on a conveyer belt A and carried to a semi-cylindrical breast 10 over which a rotating member E is supported. The member E comprises a semi-cylindrical surface 30 inclined to the axis of the member and terminating at one end in a hollow block 21 having a fluid inlet 23 and a narrow orifice 24 extending in a direction parallel to the axis of the shaft 12 to a hub on which the surface 30 is secured by a spoke 33 and plate 34. The butts of the sheaths, fed forward by the conveyer A, are gripped between the links of a pair of endless chains B and the sheaths supported on a conveyer C, arranged between two parts of the conveyer A, are led to the breast 10 by a spiral guide 35 carried on one of the spokes supporting the surface 30 and terminating in a rod 36 having its end 37 coaxial with the shaft 72; the guide 35 is cut away to permit the passage of a cutter 40 fixed to the block 21, the cutter slitting the sheaths longitudinally as the member E rotates and the stream of water under pressure issuing from the orifice 24 scraping and cleaning the fibres from pulp &c. ; teeth 41 on the block comb and hold the cleaned portion of the fibres down on the breast 10 as the fibres are traversed across the breast and a series of axially extending pins fixed to the plate 34 prevents the fibres becoming entangled with the shaft 12. As the cleaned fibres are drawn from the belt A they pass between a pair of rope conveyers D which take them out of the machine as the butts are severed therefrom by a cutter 120. The liquid under pressure is supplied to the orifice 24 through a pipe 51 from the hollow shaft 12 which is connected through a housing 52 with a valve casing 57 connected through an accummulator 58 with a constant pressure pump 56 ; the valve in the casing 57 is automatically opened by cam mechanism driven from the shaft 12 during that portion of each revolution of the wheel E when the orifice 24 is moving across the breast 10 away from the chains B. The water from the breast 10 is confined and directed to a waste pipe by a hood 68 which is cut away for the passage of the conveyer C. The links of the co-operating chains B are formed with interengaging parts of V-cross-section and are pressed into engagement by spring pressed rollers 77 engaging the lower run of the upper chain and disposed above fixed rollers 76 engaging the upper run of the lower chain ; pins 88 projecting from the links engage recesses in the side flanges of the driving pulleys 84 which are geared to the shaft 72. The water issuing from the orifice 24 preferably has a velocity head of the order of 1,500-3,000 lb. per square inch while the normal component of the force of impact of the stream on the sheaths is in excess of 1,000 lb. and preferably between 1,000 and 2,000 lb. ; the velocity of the liquid at the point of impact is in excess of 250 ft. per second. Specification 537,763 is referred to.