GB684810A - Improvements in or relating to pneumatic conveying systems - Google Patents

Abstract

684,810. Fluid-pressure servomotor-control systems. BRUNET, J. Jan. 26, 1951 [Jan. 31, 1950], No. 2034/51. Class 135 [Also in Group XXX] In a pneumatic conveying system wherein the flow of the conveying fluid is maintained constant by means of a valve under the control of a device which detects and measures variations in the flow and is arranged downstream of the valve, substantially the whole of the conveyed material is removed from the stream of conveying fluid by a separator positioned between the valve and the flow detecting and measuring device. The invention is described with reference to a system wherein three conveying conduits 35 ... 37, Fig. 1, are connected to a common header 34 to which suction is applied, and each conveying conduit is provided with an intake hopper or funnel 38, a regulating valve B<SP>1</SP>, a separator 39, and a flow detector A', the total load on the system thereby remaining constant. A stream of air from which the granular material has been removed by a filter 4, Fig. 2, flows past staggered curved surfaces 2, 3 and acts on a pivoted vane 5, the latter being loaded by a weight-and-lever system 15 so that it takes up a position corresponding to the value of the flow. The vane is also connected to a shuttle valve 9, 12 to control the connection of a conduit 14 either to the suction existing in the conduit 1 or to atmosphere past the valve 12. Conduit 14 leads to the interior of a spring-loaded bellows power device actuating a butterfly valve controlling the flow in conduit 1. In a modification, the shuttle valve 9, 12 is replaced by a single valve constituted by an extension of the vane 5.