| 摘要 |
The cooling roller, for use in a paper production, has a cylinder mantle with a surface (2) which is profiled by recesses (6). The mantle surface recesses (6) have an air expansion volume which meets the expression (I); VA = expansion vol. in m<3>; VLS = gap vol. on a roller rotation in m<3>; P infinity = ambient pressure in Pa; PLS = gap pressure in Pa; and n = poly tropical condition exponent to be selected between 1.15 and 1.35. The recesses (6) are grooves, aligned in the mantle surface (2) to have a higher component in the peripheral direction than in the axial direction. The grooves are wider than their depth, in a trapezoid or V-shaped cross-section, and cover 10-30% of the roller mantle surface (2) area. The recessed grooves (6) can be in a spiral round the roller (1), in a multiple screw structure with a pitch which 10-20 times the recess (6) groove width. The roller (1) diameter does not exceed 500 mm.
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