Fluid-dynamic means for efficaceous use of ionizing beams in treating process flows

Apparatus for treatment of a process flow by beams of ionizing radiant energy, said apparatus comprising:

• (a) a duct for conducting a process flow from upstream locations through a radiating region to downstream locations, said duct having first opposed walls, and second opposed walls joining said first opposed walls;
• (b) opposed windows, impervious to said process flow but pervious to said ionizing radiant energy, located in said first opposed walls;
• (c) ionizing radiation generating means for projecting beams of ionizing radiant energy through said windows into said duct, said beams exposing portions of process flow in said duct to differing amounts of said ionizing radiant energy defining contours of constant time-integrated exposure to said ionizing radiant energy, portions adjacent said second opposed walls being exposed to lesser amounts than other portions, said second opposed walls each substantially conforming to a contour of constant exposure to said ionizing radiant energy defining an exposure which is a predetermined small fraction of the maximum value of said exposure;
• and
• (d) drag element means disposed adjacent said second opposed walls at a location upstream of said beams, said drag element means being arranged and adapted to produce turbulence only adjacent each of said second opposed walls effective to slow substantially only said portions of process flow adjacent each of said second opposed walls and exposed to said lesser amounts of radiation sufficiently that all portions of said process flow are substantially equally treated by said ionizing radiant energy.