Intermediate Rollers Research Articles

Penstocks of the Thac Mo hydroelectric station in Vietnam

1. When designing pipelines on collapsing soils it is necessary to take into account the most unfavorable conditions from the viewpoint of bending of the pipeline—settlement of the intermediate supports every other one, all even or all odd. 2. In this case, if the amount of deflection of the penstock under load is less than the amount of settlement of the intermediate supports, it is necessary to take into account disconnection of the intermediate roller support from work. 3. Control assembly of members of the assembly links during manufacture of the oversize penstocks as well as quality control of the welded joints during enlargement are necessary conditions for achieving a high quality and eliminating losses of time during assembly. 4. To shorten the time of construction and assembly works, provided a thoroughly conducted geodetic survey, it is expedient to assemble the penstock from two sides—from the side of the water intake and from the side of the powerhouse.

Structures and magnetic properties of a Nd15Fe77B8 alloy produced by twin-roller quenching

The relationship between the magnetic properties and microstructures of flakes of a Nd15Fe77B8 alloy produced by twin-roller quenching was studied. Flakes produced at low to intermediate roller speeds (1.4–8 m/s) showed a dendritic structure of Nd2Fe14B oriented normal to the chilled surface, while flakes produced at higher roller speeds showed fine, equiaxed Nd2Fe14B grains. The flakes with a dendritic structure were found to be magnetically anisotropic and showed a high-energy product (BH)max (15.2 MGOe) in the direction perpendicular to the chilled surface. The flakes that had fine equiaxed grains were magnetically isotropic. The maximum coercivity of the flakes exceeded 20 kOe. The microstructural transition from columnar dendrites to equiaxed grains is explained in terms of morphological changes in the solidification of undercooled melts. Optimization of twin-roller quenching parameters for the production of desirable microstructures in Nd-Fe-B magnets is discussed.

Shielding of the starting strip on the intermediate roller conveyor of a 2800/1700 mill

Shielding of the starting strip on the intermediate roller conveyor of a 2800/1700 mill

20—THE EFFECT OF ROLLER VIBRATION ON YARN REGULARITY

The general nature and some causes of roller vibration are discussed briefly and a more detailed description of stick–slip roller vibrations is followed by a theoretical analysis of the effect of such vibrations on the fibre arrangement during drafting. For single-zone drafting systems, the effect of vibrations occurring at (a) the input rollers and (b) the delivery rollers is considered. The theoretical effect of vibrations of the intermediate rollers of two-zone drafting systems is shown to be very great. Natural limitations of the effect of roller vibration on the ultimate yarn are discussed. The original wavelength of vibration has been found to have a considerable effect on the amplitude of variation of fibre arrangement introduced by roller vibration. The effects of the wavelength/fibre-length relationship and imperfections in drafting, which have been fully treated elsewhere, are regarded as factors tending to reduce the ill effects of roller vibration. A theoretical study of the effectiveness of o...