Abstract: Described herein are devices and methods for reducing thermal stresses in a rotating, foraminous thin-shelled roll for drying permeable and semi-permeable webs by blocking axial flow of heated air through an axial channel formed between two corrugated layers in the shell. The axial channels extend between spaced-apart, parallel end members each having an inner face, and a plurality of alternating straight thin divider strips and bent thin strips extending axially between and evenly-spaced around the circumference of the inner faces of the end members to form an annular cylinder with radial channels therethrough. Affixing at least one impermeable insert into a radial channel so that it extends through the radial channel and across at least a portion of the faces of the two tiers of bent strips blocks the axial channel therebetween and prevents the passage of air therethrough to the end member.

Abstract: The present invention includes a nozzle insert for use in a drying machine of the type used in paper web drying. The nozzle insert of the present invention includes at least one intake having a central portion, wherein a pair of center vanes is disposed for directing airflow. The central portion is bounded by at least one turning vane adapted for directing airflow in a lateral direction. For each turning vane, there is at least one straightening vane adapted for curtailing swirling of the airflow. The vanes are oriented at optimal angles for directing the flow of the nozzle in a lateral direction, while permitting some air to penetrate the central portion through a series of ports. The intakes are bounded by a series of insulated bulkheads, which serve to direct airflow and contain heat-loss through thermal emission.

Abstract: The present invention relates to novel dryer systems that incorporate two-stage processes for heating air for drying a traveling web. The present invention is operable within a drying system having a drying hood containing a dryer. The drying hood receives heated air through an intake and expels system air through an exhaust. The portion of system air that is maintained in the system is divided into two portions and directed into separate parallel conduits for two-stage heating that results in greater temperature uniformity and efficiency within the system. One loop includes a mixing chamber for the initial mixing of system air with the combustion products of a burner. A second loop includes an injection chamber that receives the initially mixed air and injects it into the other portion of the system air, resulting in greater temperature uniformity within the drying hood and increased operating efficiency for the entire system.

Abstract: The present invention includes a nozzle insert for use in a drying machine of the type used in paper web drying. The nozzle insert of the present invention includes at least one intake having a central portion, wherein a pair of center vanes is disposed for directing airflow. The central portion is bounded by at least one turning vane adapted for directing airflow in a lateral direction. For each turning vane, there is at least one straightening vane adapted for curtailing swirling of the airflow. The vanes are oriented at optimal angles for directing the flow of the nozzle in a lateral direction, while permitting some air to penetrate the central portion through a series of ports. The intakes are bounded by a series of insulated bulkheads, which serve to direct airflow and contain heat-loss through thermal emission.

Abstract: A through-air device includes a permeable roll having a hollow interior and mounted for rotation about a longitudinal axis. At least one divider is located in the hollow interior so as to define a plurality of roll channels within the roll, the roll channels being positioned side-by-side along the longitudinal axis. A first housing bounds a first portion of the roll, and a second housing bounds a second portion of the roll. At least one partition is located in the second housing so as to define a plurality of housing channels within the second housing. Each one of the housing channels is aligned with a corresponding one of the roll channels. The device further includes structure for individually controlling airflow through each pair of corresponding roll channels and housing channels.

Abstract: An air processing cylinder useful in drying, curing, thermal bonding, cooling, and web transferring materials such as fabrics, papers, and the like. Air is exhausted out of the cylinder surface through a plurality of conduits equipped with distribution means for profiling the flow of air. The drying cylinder further includes a duct network on its outer shell for exhausting air out of one axial area only or, alternatively, the drying cylinder may contain multiple duct networks for exhausting air out of several axial areas, each having its own flow characteristics.

Abstract: An apparatus for drying a travelling wet fibrous web is provided which comprises a rotating air-permeable drum. The drum is at least partially surrounded by a hood which has an interior space for receiving a flow of air and directing the flow of air through a permeable inner wall towards the outer surface of the drum. At least a portion of the hood is divided into individual sections in a cross-machine direction. Apparatus is provided for supplying a flow of drying air at a first temperature to the hood, and for supplying profiling air at a selected different temperature different from the first temperature to at least one of the individual sections.

Abstract: An apparatus for drying a travelling wet fibrous web is provided which comprises a rotating air-permeable drum. The drum is at least partially surrounded by a hood which has an interior space for receiving a flow of air and directing the flow of air through a permeable inner wall towards the outer surface of the drum. At least a portion of the hood is divided into individual sections in a cross-machine direction. Apparatus is provided for supplying a flow of drying air at a first temperature to the hood, and for supplying profiling air at a selected different temperature different from the first temperature to at least one of the individual sections.