Yankee drying hood and method comprising angled impingement nozzles

A method of drying a paper web upon a drying cylinder using angled air nozzles directed at an angle alpha, comprising:

• (a) providing a rotating drying cylinder having an exterior surface;
• (b) providing a drying hood adjacent the exterior surface of the drying cylinder, the hood comprising a drying zone of heated air, the hood further comprising nozzles adapted to supply relatively high speed hot air streams into the drying zone of the hood, the nozzles being oriented at an angle deviating from perpendicular in the downstream machine direction designated alpha;
• (c) applying a wet web to the exterior surface of the cylinder, the wet web being rotated by the cylinder at a web sheet speed;
• and
• (d) rotating the wet web upon the exterior surface of the cylinder through the drying zone of the hood while simultaneously directing hot air streams from the nozzles upon the web;
• and
• (e) providing a hot air stream from a nozzle at an angle alpha that deviates from perpendicular according to the following equation:
• sin alpha angle=Ws/An;
• wherein Ws is the wet web speed and An is the speed of air provided from the nozzle.