GB457654A - Improvements in and relating to apparatus for refining fibrous material in a liquid medium - Google Patents

Abstract

457,654. Refining - engines for paper pulp ; grinding or crushing mills; fluidpressure servomotor controlled systems. NOBLE & WOOD MACHINE CO., Hoosick Falls, New York, U.S.A. March 28, 1935, No. 9669. Convention date, March 28, 1934. [Class 96] [See also Groups II and XXIX] In a refining-engine wherein paper pulp &c. is ground between the periphery of a rotor 1, Fig. 1, and adjustable radial stator units or bedplates 20, 21 supported on the rotor casing and extending circumferentially between a feed chamber 23 receiving pulp under pressure and a discharge chamber 24, both chambers being peripheral of the rotor, the bed-plates 20, 21 are moved independently to and from the rotor to form a substantially continuous treatment zone of variable length according to the number of units in use. The rotor 1 which may have a peripheral speed of 12,000 feet per minute has grooves 37 into which pulp is forced by the feed pressure, over-sized particles, wire, gravel, &c. being stopped by a projection 22 of the first bedplate 20, and discharged at 25 when a gate 45 is opened by a handle 47, Fig. 19, by flushing due to the pulp stream which is deflected by the gate 45, and which may be aided by water from a nozzle 48. The bedplates, which may be of wood, metal, &c. may have grooves 205, Fig. 9, or holes 206 at the working face and each is carried on a rod 79 of a piston 81, the position of which is indicated by a rod 150, the cylinder blocks having under cut grooves 44 in their sides and ends to intercept solid particles and prevent leakage from the casing. The bedplate pressure may be controlled individually or in groups, by hand, or automatically in response to variations in feed pressure of the pulp, a feeler pipe 121, Fig. 1, communicating with a diaphragm 119, Fig. 15, deflecting, by a plate 122 and extension 123, a smaller diaphragm 120 and opening a valve 131 against spring pressure, allowing water from a pipe 106 to flow to the pistons 81, e.g. through valves &c. controlling their relative pressure, ducts 133 and 139 allowing equalization of pressure about the valve 131 and its plunger 138 respectively. Pressure in the feed chamber 23 may be kept constant by pumping the pulp supply from a tank 201, Fig. 19, through a valve 160A in a pipe 160 allowing part of the pulp to return through a pipe 155, the valve 160A being actuated by a piston &c., to either side of which fluid under pressure is admitted through pipes 168, 169 from a pilot valve 170 controlled by a lever 173 pivoted at 174 to be moved between adjustable stops 184, 185 by a diaphragm 177 &c. connected with the feeler pipe 121. The lever 173 is adjustably weighted at 175 and may be locked out of operation by engagement of an arm 187 with a pin 186. The area of the opening of the valve 160A is proportional to the square of the movement of the piston controlling it. In a modification, the valve 160A is substituted by one which is opened by the pressure in the pipe 160 acting against the pressure due to a weighted lever. Specifications 457,701, 457,702, and 458,919 are referred to.