| 摘要 |
<p>Method and apparatus for pneumatically spreading a particulate substance for treating the ground. The particulate substance is blown from a hopper through tubes to distribution points. A nozzle is received on the outlet end of each tube. The flow is divided in the nozzle into several parts which are concentrated in inverted chutelike of different lengths and then sprayed towards the ground, perpendicular thereto in the central zone and progressively more obliquely towards the marginal zones. The central zones are covered with a uniform amount of particulate substance which decreases in the marginal zones stepwise or uniformly. The marginal zones of consecutive adjacent passes overlap each other. Various ways of decreasing the distribution of the particulate substance in the marginal zones are described.</p> |
