A rotary joint for connecting a stationary body to a rotating body. The rotary joint has a rotatable wear plate connectable to the rotating body and a seal ring seated in the wear plate. A spring-biased piston engages the seal ring against the wear plate by compressed springs between an end flange and the piston. The end flange and the piston are at least partially disposed within a shroud, wherein the shroud has at least one aperture extending there through. Alignment rings are formed on the piston and viewable through the aperture in the shroud to confirm the proper distance between the end flange and the piston and the proper force applied to the piston. A seal wear indicator is connected to the piston and moves between an exposed position, wherein the seal ring is not worn, and a non-exposed position, wherein the seal ring is worn.

The present invention relates to a process for manufacturing a Yankee cylinder. The process comprises welding the first reinforcement flanges of two workpieces of Yankee cylinder section from inside of the cylinder case, preheating and welding the two workpieces of Yankee cylinder section from outside of the cylinder case, and then removing the first, second reinforcement flanges, radial inner end area of the weld and their surrounding material in the workpieces of the Yankee cylinder section, so that the joint of the two workpieces of Yankee cylinder section is machined to meet the final dimension requirements for the Yankee cylinder inner grooves. The present invention is also related to a workpiece of Yankee cylinder section used in the said process.

A method of applying a long lasting wear-resistant coating on a Yankee drying cylinder (1), the method comprises: the step of providing a Yankee drying cylinder (1) having a cylindrical shell (2) with a circular cross-section and an outer surface (3); the step of performing a thermal spray operation to form a wear-resistant coating layer (4) on the outer surface of the Yankee drying cylinder (1) during which thermal spray operation coating feedstock (6) is fed to at least one spray device (5), heated to become plastic and/or semi-molten and/or molten and sprayed onto the outer surface (3) of the Yankee drying cylinder (1) to form the wear-resistant coating layer (4), the coating feedstock (6) for the thermal spray operation consisting of: 1.5 to 2.5 weight percent Al 0.0 to 0.2 weight percent Ti, 9.5 to 10.5 weight percent Si, 0.0 to 0.2 weight percent B, 12.5 to 14.2 weight percent Mo, 0.0 to 0.2 weight percent V, 0.0 to 0.2 weight percent C, 0.000 to 0.020 weight percent Cr, 4.5 to 6.0 weight percent Mn, 0.0 to 0.2 weight percent Mg, 0.0 to 0.2 weight percent Ni, 0.0 to 0.2 weight percent Nb, the remainder being iron and impurities.

Coatings and Yankee cylinders with such coatings are also disclosed.

The air hood (3) for Yankee rolls (1) comprises at least one supply circuit (5, 6, 7) to supply dry hot air towards outlets (7A) to a working area, and at least one suction circuit (11) to suck wet air from the working area. The hood comprises a thermal insulation insulating at least partially the supply circuit from the suction circuit.

The invention relates to a Yankee drying hood arrangement (1) which has a first temperature main supply conduit (9, 9′) for a fluid such as hot air, or hot air and steam and/or water vapour, at a first temperature T1 and a second temperature main supply conduits (10, 10′) for a fluid such as hot air, or hot air and steam and/or water vapour, at a second temperature T2 which is not the same as T1, the first temperature and second temperature main supply conduits (9, 9′, 10, 10′) being in communication with the distributor conduits (8) such that a fluid such as hot air can stream from the first temperature and second temperature main supply conduits (9, 9′, 10, 10′) to the distributor conduits (8), wherein at least one distributor conduit (8) is provided with damper means (31) for changing the ratio between amount of fluid at temperature T1 from the first temperature main conduit and the amount of fluid at temperature T2 from the second temperature main conduit that streams into the distributor conduit.

The present invention relates to a process for manufacturing a Yankee cylinder. The process comprises welding the first reinforcement flanges of two workpieces of Yankee cylinder section from inside of the cylinder case, preheating and welding the two workpieces of Yankee cylinder section from outside of the cylinder case, and then removing the first, second reinforcement flanges, radial inner end area of the weld and their surrounding material in the workpieces of the Yankee cylinder section, so that the joint of the two workpieces of Yankee cylinder section is machined to meet the final dimension requirements for the Yankee cylinder inner grooves. The present invention is also related to a workpiece of Yankee cylinder section used in the said process.

A through-air apparatus for drying or bonding paper or non-woven products is provided. The apparatus includes a through air roll, a first tension plate configured to hold a wire sleeve which is configured to extend around the roll, the first tension plate including at least one tension arc segment. The apparatus also includes a first cam mechanism associated with the at least one tension arc segment, wherein the first cam mechanism is configured to move the tension arc segment to adjust the position of the tension arc segment relative to the outer circumference of the first end of the roll, so that as the roll and first tension plate rotate about the first axis, the first tension plate is concentric with the roll.

A method for manufacturing a steel Yankee drier including a cylindrical steel mantle with two end heads on each of which a corresponding pin is arranged, the cylindrical mantle having an external surface and an internal surface, and the internal surface of the mantle in cooperation with the end heads delimiting an internal chamber of the Yankee drier in which steam can be introduced. The surface protective coating is at least partially formed on the internal surface of the mantle by introducing a predetermined amount of a nickel bath in a volume delimited in a radial direction by the internal surface of the mantle, followed by a permanence of the bath in said volume for a predetermined time. The surface protective coating protects the internal surface of the mantle from corrosive and/or abrasive agents contained in the steam introduced into said chamber.

A method for treating a Yankee cylinder, where the Yankee cylinder has a cylinder shell made of steel with a ferritic-pearlitic structure. In the disclosed method, the outer surface of the cylinder shell is heat-treated with a laser beam and hardened as a result.

A Yankee drier including a cylindrical mantle to which two end heads are connected, on each of which a corresponding pin is arranged, wherein the cylindrical mantle has an external surface and an internal surface, and wherein the internal surface of the mantle in cooperation with the lateral heads delimits an internal chamber of the Yankee drier in which steam can be introduced. The internal surface of the mantle is at least partially provided with a surface protective coating, the surface protective coating protecting the internal surface of the mantle from corrosive and/or abrasive agents contained in the steam introduced into said chamber.