Patent GB-515944-A (GB)
Title: Apparatus for disintegrating vegetable fibrous materials
IPC: B02C7/08
Filed: 1938-06-13
Abstract: 515,944. Disc mills. BASLER, H. June 13, 1938, No. 17547. Convention date, June 12, 1937. [Class 59] A mill for fibrous material comprises a crushing device having relatively movable grinding elements and operating intermittently either with or without a pressure feed, said device, if desired, co-operating with means producing chemical comminution ; an adjacent receptacle for receiving the finished material, a disintegrating chamber in advance of the crushing device and an annular member supported on one of said elements for adjustment in a direction towards and away from the other element to vary the discharge crosssection between the grinding surfaces independently of the distance between them. As shown, fibrous material is fed'to a hopper 2, Fig. 1, connected by a valve 3 to a pre-steaming container 4, the lower part of which communicates through a valve 5 with a steaming container 6. The steamed and disintegrated material is fed through a rotary valve 7 to a disc mill 8 and is discharged through an outlet 30 to a container 9 closed at the bottom by a valve 10. The mill shaft 11 is driven by a belt 13 from a motor 14 and the container 6 is supplied with steam by pipe 15 controlled by valve 16. The container 4 is supplied with steam at a lower pressure than that in chamber 6 through a pipe 17 connected by pipe 17<1> to an auxiliary supply, the pipe 17 also communicating with the disc mill 8 and a condenser 21. The disc mill 8 comprises a cover 28 provided with grinding surfaces 59, 61 which co-operate with grinding surfaces 60, 62 on a rotary disc 31, the surfaces 60 and, if desired, the surface 59, may have semi-circular ribs. An annular grinding surface 63, adjustable by bolts 65, surrounds the fixed grinding surfaces 59, 61 and is movable relatively to the peripheral portion of the rotary disc 31 to regulate the discharge opening of the disc and the duration of the passage of the material through the mill. The mill shaft 11 has the footstep bearing supported on a spring and is adjustable by a screwed hand-wheel to vary the clearance between the grinding discs. The upper end of the shaft 11 is supported in a bearing 45 which is protected by a splash ring 46. The shaft is sealed in the mill casing by a splash ring 37 and a packing 40 retained.in position by a gland 43, the liquid passing along the shaft being drained through ducts 42, 39. The material is subjected to a preliminary treatment with steam in chamber 4, the contents are then discharged into chamber 6 into which steam at a higher pressure is injected through valve 15, the chamber 4 being closed. The material is then fed by rotary device 7 to the centre of the grinding discs and is forced through the discs by the steam pressure, centrifugal force and weight of material. The steam in the discharge side of the mill is led through pipe 17 back to chamber 4 which has been refilled with fresh material and the process is then repeated. The pipe 17 supplies steam for starting and for making up the supply when the exhaust steam from the mill is insufficient. A single chamber may replace the chambers 4, 6 and the plant may be used without pressure, a constant flow of water being used to feed the material through the mill,