A nozzle (10) for contact-free treatment of a running web, having a main frame (11) forming an outer part of the nozzle, and two side chambers (14, 15) on each of the longitudinal sides of the nozzle (10). The side chambers having openings (17A, 17B, 16A, 16B) for the air to blow toward a fiber web. A U-shaped air channel (20), through which the air is lead to the side chambers (14, 15), located between the side chambers (14, 15), having at least one opening (19, 18) on each side wall for leading the air into the side chambers (14, 15). A U-shaped inner part (13) which is movable by a mechanism (12) comprising a screw (21) and bushings (22) to at least partially open and close the opening (18, 19).

A nozzle (10) for contact-free treatment of a running web, having a main frame (11) forming an outer part of the nozzle, and two side chambers (14, 15) on each of the longitudinal sides of the nozzle (10). The side chambers having openings (17A, 17B, 16A, 16B) for the air to blow toward a fiber web. A U-shaped air channel (20), through which the air is lead to the side chambers (14, 15), located between the side chambers (14, 15), having at least one opening (19, 18) on each side wall for leading the air into the side chambers (14, 15). A U-shaped inner part (13) which is movable by a mechanism (12) comprising a screw (21) and bushings (22) to at least partially open and close the opening (18, 19).

A nozzlebox for blowing hot gas in the convective drying zone of equipment for the continuous drying of air-borne paper sheets comprises at least one direct impingement nozzle for ejecting a jet of hot gas perpendicular to the average plane of the paper sheet to be dried. The nozzle box comprises a plurality of inclined jet nozzles for ejecting jets of hot gas under an inclined angle with respect to the average plane of the paper sheet to be dried. At least two inclined jet nozzles are provided for which the plane comprising the vector representations of the jet directions of the at least two inclined jet nozzles does not comprise the vector representing the jet direction of a direct impingement nozzle.

Described herein are methods and systems for reducing, preventing, or eliminating wrinkles in a paper sheet during papermaking. The systems may include a dryer configured to dry a continuous paper sheet having a travel direction. The system may also include at least one roll configured to receive the dried continuous paper sheet. The systems may also include an air spreader located downstream of the dryer and upstream of the at least one roll. The at least one roll may include one or more calendering rolls. The air spreader may include a plurality of nozzles configured to expel a gas toward the dried sheet. The nozzles may be oriented in a direction at least partially opposed to the travel direction of the dried sheet.

Described herein are methods and systems for reducing, preventing, or eliminating wrinkles in a paper sheet during papermaking. The systems may include a dryer configured to dry a continuous paper sheet having a travel direction. The system may also include at least one roll configured to receive the dried continuous paper sheet. The systems may also include an air spreader located downstream of the dryer and upstream of the at least one roll. The at least one roll may include one or more calendering rolls. The air spreader may include a plurality of nozzles configured to expel a gas toward the dried sheet. The nozzles may be oriented in a direction at least partially opposed to the travel direction of the dried sheet.