Abstract: Methods and apparatus for detecting wear in a liner. In one embodiment of the present invention, an electrically conductive wire is placed on or near the outside surface of the liner and the electrical resistance in the electrically conductive wire is measured to determine whether the wire has worn through. In another embodiment of the present invention, the temperature measured by a temperature measuring device, such as a thermocouple, is monitored over time to estimate wear in the liner.

Abstract: A novel air knife. The novel air knife is circumferential. That is, the novel air knife injects a gas stream along the inside walls of the air knife. The air knife can be advantageously placed at or near the entrance to a suspension vessel to reduce buildup of solid materials transported to the suspension vessel. The gas stream is injected at a rate sufficient to reduce the buildup of solid materials on the walls of the air knife (and thus at the entrance to the suspension vessel). The air circumferential air knife is particularly useful in a TiCl4 production process for reducing buildup of hygroscopic cyclone dust at the entrance to a suspension vessel.

Abstract: A novel air knife. The novel air knife is circumferential. That is, the novel air knife injects a gas stream along the inside walls of the air knife. The air knife can be advantageously placed at or near the entrance to a suspension vessel to reduce buildup of solid materials transported to the suspension vessel. The gas stream is injected at a rate sufficient to reduce the buildup of solid materials on the walls of the air knife (and thus at the entrance to the suspension vessel). The air circumferential air knife is particularly useful in a TiCl4 production process for reducing buildup of hygroscopic cyclone dust at the entrance to a suspension vessel.