Abstract: The present invention provides a method and apparatus for controlling the fluid flow bias of continuous, multiple zone processes having gas or vapor comprising atmospheres that are in immediate access to each other. Active control of the fluid flow bias in at least one process zone or control of the overall process fluid flow bias is achieved by applying force to at least one of the zones of the process in a manner which enables such control. A physical or chemical property or a change thereof in at least one process atmosphere is monitored and an appropriate amount of force is applied in response to the monitored property. The monitored property is related to the furnace flow bias by an algorithm, so that the flow bias can be controlled by controlling the at least one chemical or physical property monitored.

Abstract: The in-situ cleaning of conduits containing oily deposits is facilitated by the concurrent passage of cleaning particles and a non-agglomerating drying agent therethrough in a propelling gas stream. In cycling cleaning operations, the preliminary injection of drying agent into the conduit prior to said concurrent use of cleaning particles and drying agent further enhances the overall in-situ cleaning operation.

Abstract: The in-situ cleaning of conduits is enhanced by the passage therethrough of a propelling gas stream having entrained therein cleaning particles of a regular, non-random configuration, and having less than spherical symmetry.