Abstract: A lance system for lancing gas into a molten metal furnace wherein primary gas is passed into a furnace as a coherent jet enveloped in secondary gas provided into the furnace through a plurality of secondary openings communicating with respective secondary passages having restrictions within the lance set back from the lance face.

Abstract: The maximum useful rate of aluminum refining is substantially increased by the incorporation of baffle means across the refining chamber under the rotor of a spinning nozzle assembly positioned in the refining chamber during aluminum refining operations.

Abstract: A method for automatically controlling the restrictors in a ram-tube type refuse compacter or pelletizer. Variable restrictors near the discharge end of the tube control the compaction pressure exerted on the refuse as it is forced through the tube. The restrictors are capable of being moved inward and outward on each ram stroke in response to changes in the ram pressure required to advance the compacted refuse through the tube. The method comprises:(1) measuring the ram pressure during the last smallest practicable increment of forward ram travel,(2) adjusting the restrictors slightly inward if the pressure measured in step (1) is less than a predetermined pressure P.sub.1,(3) measuring the ram pressure when the ram is at the lock-out point, normally about 6 inches from the forward end of its stroke,(4) overriding step (2) by making no inward restrictor adjustment if the pressure measured in step (3) is less than a predetermined pressure P.sub.

Abstract: Apparatus for collection and removal of settled solids from the bottom part of an arcuate sedimentation zone, comprising a scraper blade suspended by cable means from a bridge and drawn reciprocatingly and repetitively in an arcuate path around the sedimentation zone. Means are provided for shortening the suspended lengths of the cable means at the approach of the bridge to a radial end wall of the zone so that the scraper blade is drawn toward the wall for radial alignment therewith, thereby eliminating unscraped `dead space` adjacent the end walls.