Abstract: A device for promoting gravity flow of zirconium tetrachloride and other non-free-flowing solids has a rotatable shaft. At least two flexible lengths have first ends attached to and axially spaced on the shaft and also distal second ends. A collar is slidably mounted on the shaft between the spaced first ends of the flexible lengths for slidable axial and circumferential movement on the shaft. At least one sweep arm has a first end pivotally attached to the collar and a second distal end attached to the second distal ends of the flexible lengths. The collar slides relative to the shaft as the sweep arm encounters resistance from bridged solids. The relative movement of the collar and shaft causes the flexible lengths to wrap around the shaft and the arms to collapse toward the shaft. A device with collapsible arms will have a minimal torque requirement. When the solids dislodge from the collapsed sweep arms, the arms extend to sweep outwardly to a maximum extent.

Abstract: A pressurized fluid is injected into a mass of material through at least one length of hose or other tubing of inherently resilient, elastomer material having one end closed and provided with at least one series of potential openings cut into the elastomer material along the length of the tubing so as to be normally tightly closed by reason of the resilency of the elastomer material but stretched open under the influneces of the pressurized fluid, which is introduced through the opposite end of the length of tubing. Gravity discharge of particulate material from a vessel having a hopper portion at its bottom can be effectively activated in this manner by the fluid-injection device of the invention.

Abstract: A filter cleaning process for filters for separating particulates from a hot gas stream using hollow, tubular filter elements. Blowback and hot purge gas systems provide for cleaning of the filter elements and maintenance of the blowback system clear of the solids or condensation products that might form during separation. The process is especially useful in filtering solids from a hot, corrosive gaseous stream, such as a zirconium tetrachloride process gaseous stream, where the gas stream contains gaseous constituents that are subject to condensation directly to a solid during separation of the particulates and prior to discharge from the filtering apparatus.