Abstract: A guide roll for a porous belt, for instance for the drying wire of a paper machine, is described. A perforated roll shell rotates about a stationary air guide box. The guide box has two air chambers which extend across the length of the guide roll. One air chamber serves the discharge of blowing air and the other air chamber serves the intake and removal of suction air. Contained between the air guide box and the roll shell is an annular space in which a blowing zone and a suction zone are defined by longitudinal seals. Considering that blowing air and suction air may have different temperatures, the two air chambers of the air guide box are movable axially relative to each other.

Abstract: A roll assembly having a roll cylinder, a roll core and pressure transfer elements, which assembly is tightened for a grinding operation by applying hydraulic pressure through the pressure transfer elements and aligning the plane of the hydraulic overall pressure force to reduce to about zero the bearing play in the area of the contact line of the grinding wheel. The roll cylinder is mounted on the roll core through antifriction bearings, and in the finished apparatus, such as a calender, reduction of bearing play will compensate for wall thickness errors in the races of the antifriction bearings.

Abstract: A press roller is provided which permits adjustable bowing under load. The press roller has a hollow, rotatable roller casing through which a stationary cross head extends. A semi-circular pressure chamber is formed between the cross head and the roller casing. In this chamber, two annular pistons are provided which rest on one end surface of the inner surface of the roller casing and are guided in a sealing manner in recesses in the cross head. To prevent bending oscillations by the cross head, the annular pistons enclose substantially rigid fluid cushions which are isolated from one another.

Abstract: A drying cylinder adapted to receive steam therein includes a cylindrical cylinder jacket and two end covers. There is a flange connection between the jacket and the covers. The jacket has a rectangular cross-section flange. The covers have an L-shaped flange which receives the end flange of the cover. The covers are concave to the outside of the cylinder. The point of intersection of a curved line through the cover and of the axial center line of the axial arm of the cover flange lies at a distance from the outer face of the flange of the end cover that is at most about 60% of the axial length of the axial arm of that flange. There is thermal insulation on the axially exterior side of each cover.

Abstract: A Yankee clyinder whose internally heated shell consists of steel or cast iron and is provided with an external layer of pure or alloyed copper, molybdenum, tungsten or another metal whose thermal conductivity greatly exceeds (and preferably amounts to at least twice) the thermal conductivity of the material of the shell. The thickness of the layer is in the range of 0.4-2 millimeters, and the thermal expansion coefficient of its material is identical to or approximates that of the material of the shell. The layer can be applied to the periphery of the shell in molten state in the form of a finely atomized spray. The drying action of such cylinder upon a running paper web greatly exceeds the drying action of a cylinder whose shell consists exclusively of cast iron or steel.