Patent ID: 6354465
Filing Date: 2002-03-12
Classification: G01G

Abstract:
A portable device for delivery and metering of cohesive powders comprising:(a) a hopper supported on a frame, wherein the hopper has an opening into which the cohesive powder is charged formed by vertical walls and a section of generally converging walls connecting the vertical wall to an opening through which material is discharged wherein at least the portion of the hopper having converging walls is lined with a pneumatic fluidizing membrane; (b) a flow control mechanism; (c) a means of measuring and controlling the weight of material discharged; (d) a control loop to close the flow control mechanism when the desired weight has been discharged from the hopper; and (e) means to render the device portable; wherein the flow control mechanism is a valve assembly comprising a piston valve having a cone shaped closure member, a body comprising a cylinder of which the interior walls are lined with a pneumatic fluidizing membrane, an automatic means by which the valve is moved downward and upward between the open and closed positions and is oscillated at selected amplitudes and frequencies about the opened position and a ring forming a valve seat wherein the ring has slots through which a flow of gas is directed.