| 摘要 |
PURPOSE:To prevent sufficiently coal dust from flying up and scattering by erecting on a partition wall a mesh-like fence of which the lower side has mesh pitch smaller than that of the upper side. CONSTITUTION:when wind blows in the direction of arrow P, a potion of the wind passes through one gauges 13, 14 and flows on the upper portion of the interior of a partition wall 11 as shown by arrow Q to produce a spiral flow in the interior of the partition wall 11 as shown by arrow R. When wind passes through the gauges 13, 14, the flow speed of the wind is reduced so that the flow speed of said spiral flow becomes very small and flying-up coal dust is substantially reduced. Since mesh pitch of the gauge 14 is smaller than that of the gauge 13, wind passing through the neiborhood of the upper end of the partition wall 11 is more decelerated so that the flow speed of said spiral flow is effectively decelerated. |
