Water-removing apparatus for papermaking process

A water-removing apparatus for a papermaking process, having a machine direction and a cross-machine direction perpendicular to the machine direction, the apparatus comprising:

• a fluid-permeable web support designed to receive a fibrous web thereon and to carry the web in the machine direction;
• a pulse generator designed to generate oscillatory air or gas therein, having frequency from about 15 Hz to about 250 Hz;
• and
• a gas-distributing system in fluid communication with the pulse generator, the gas-distributing system terminating with a plurality of discharge outlets juxtaposed with the web support for delivering the oscillatory flow-reversing air or gas onto the web disposed on the web support, the web support and the discharge outlets forming an impingement distance Z therebetween, the plurality of the discharge outlets comprising a predetermined pattern defining an impingement area of the web corresponding thereto, the plurality of the discharge outlets providing a substantially uniform oscillatory field of flow-reversing gas between the impingement area and the discharge outlets;
• a means for generating a non-oscillatory and substantially steady-flow gas and impinging the non-oscillatory gas onto the impingement area of the web.

A water-removal apparatus for use in a papermaking process, having a machine direction and a cross-machine direction perpendicular to the machine direction, the apparatus comprising:

• a drying cylinder having a surface designed to carry a fibrous web thereon in the machine direction;
• and
• at least one pulse combustor comprising
• a combustion chamber designed to generate combustion gas therein, having a predetermined frequency from about 75 Hz to about 250 Hz, and
• a resonance gas-distributing system in fluid communication with the combustion chamber, for transforming the combustion gas into oscillatory flow-reversing gas and delivering the oscillatory flow-reversing gas onto the web, the resonance gas-distributing system terminating with a plurality of discharge outlets having a predetermined pattern and juxtaposed with the surface of the drying cylinder for impinging the oscillatory flow-reversing gas onto the web disposed thereon.