Patent ID: 7017279

Claim:
A method of blowing drying gas against a paper web with an impingement dryer, so as to control a cross-profile of the paper web, said method comprising: blowing the drying gas from a plurality of profiling chambers directly against the paper web, each profiling chamber extending in a machine direction and the profiling chambers being adjacently disposed in the cross-direction of a paper machine, such that each profiling chamber blows the drying gas to its own effective area of the paper web in the cross-direction of the paper machine; and collecting the drying gas blown against the paper web into a return air chamber via return air ducts in communication with the return air chamber and arranged between adjacent profiling chambers so as to separate the profiling chambers, the profiling chambers and the return air ducts being arranged such that drying gas blown against the paper web from the profiling chambers is returned into the return air chamber through the return air ducts-without the drying gas from one profiling chamber affecting the effective area of the adjacent profiling chamber.