Patent Number: 062360558
Section: summary

BACKGROUND OF THE INVENTION The present invention generally pertains to irradiation systems that utilize a conveyor system for transporting articles through a target region scanned by radiation from a radiation source and is particularly directed to an improvement in positioning the radiation shielding material of the system. A prior art irradiation system that utilizes a conveyor system for transporting articles through a target region is described in U.S. Pat. No. 5,396,074 to Peck et al. In such prior art system, the radiation source and a portion of the conveyor system are disposed in a chamber defined by concrete walls, wherein such concrete walls and additional concrete walls defining an angled passageway into the chamber for the conveyor system shield loading and unloading areas located outside of the chamber from radiation derived from the radiation source. SUMMARY OF THE INVENTION The present invention provides an article irradiation system, comprising a radiation source positioned for scanning a target region with radiation; a conveyor system including a process conveyor positioned for transporting articles in a given direction through the target region; radiation shielding material defining a chamber containing the radiation source, the target region and a portion of the conveyor system; wherein the radiation source is disposed along an approximately horizontal axis inside a loop defined by a portion of the conveyor system and is adapted for scanning the articles being transported through the target region with radiation scanned in a plane transverse to the given direction of transport by the process conveyor; and an intermediate wall of radiation shielding material positioned within the loop and transverse to said approximately horizontal axis. The intermediate wall supports a ceiling of the chamber, inhibits photons emitted from a beam stop disposed in a given wall of the chamber from impinging upon at least one other wall of the chamber and restricts flow throughout the chamber of ozone derived in the target region from the radiation source. Additional features of the present invention are described with reference to the detailed description of the preferred embodiments.