Abstract: A readily replaceable light rod assembly for coupling infrared energy to a photoelectric sensor element in a spark detector system used for monitoring a zone through which fine particulate matter is conveyed at high speed by pneumatic action. The light rod assembly comprises an elongate clad glass rod of optical glass, polished at both ends, positioned inside a tubular housing of Teflon material. The glass rod is fastened inside the housing by a set screw and both ends of the housing are threaded, with the input, or high thermal energy end, screwing into an end cap holding a quartz glass window, and the other, or output end, into the threaded receptacle of the sensor element.

Abstract: A separator for a pneumatic conveyor system having fixed wall and a movable wall jointly defining a chamber of greater crossection than a conduit supplying a particulate carrying airflow. An inlet discharges the airflow into the chamber and into impingement with the movable wall to initiate particle separation.

Abstract: A filter structure supporting a series of tubular filter bags for filtering a dust-laden airflow. The filter bags are subjected to a momentary reverse flow for purging collected particles from the bag walls. The filter bags are supported against pressure drops existing across the bag walls by bag shaping members affixed at spaced intervals along each filter bag. Each bag shaping member is retained in an adjustable, annular pocket formed by a cuff secured to the bag wall. This cuff is provided with a sizing means which permits contraction of the pocket to confine the shaping member therein and expansion of the pocket to permit convenient removal of the shaping member therefrom prior to laundering of the filter bag.