Patent ID: 7408174

Claim:
A fluid treatment system comprising: an inlet; an outlet; a fluid treatment zone disposed between the inlet and the outlet, the fluid treatment zone having disposed therein an array of rows of radiation source assemblies; each radiation source assembly having a longitudinal axis transverse or parallel to a direction of fluid flow through the fluid treatment zone; each row comprising a plurality of radiation source assemblies in spaced relation in a direction transverse to the direction of fluid flow through the fluid treatment zone to define a gap through which fluid may flow between an adjacent pair of radiation source assemblies; all rows in the array being staggered with respect to one another in a direction orthogonal to the direction of fluid flow through the fluid treatment zone such that the gap between an adjacent pair of radiation source assemblies in an upstream row of radiation source assemblies is partially or completely obstructed in the direction of fluid flow by at least two serially disposed downstream rows of radiation source assemblies.