Patent ID: 7918038

Claim:
An apparatus for treating a moving substrate of indefinite length, comprising: (a) a control surface comprising a condensing surface in close proximity to a surface of the substrate to define a control gap between the substrate and the control surface; (b) a first chamber near the control surface, the first chamber having a gas introduction device; (c) a second chamber near the control surface, the second chamber having a gas withdrawal device, and the control surface and the chambers together defining a region wherein the adjacent gas phases possess an amount of mass; wherein upon inducing transport of at least a portion of said mass within said region: M1 means total net time-average mass flow per unit width into or out of the region resulting from pressure gradients, M1′ means the total net time-average mass flow of a gas per unit width into the region through the first chamber from the gas introduction device, M2 means time-average mass flow per unit width from or into at least one major surface of the substrate within the region, M3 means total net time-average mass flow per unit width into the region resulting from motion of the material, and M4 means time-average rate of mass transport through the gas withdrawal device per unit width such that M1+M1′+M2+M3=M4; and desired gas phase components are collected without substantial dilution by ambient air.