| 摘要 |
<p>A sampling system (18) is disclosed for cross-stream sampling of bulk material (21) from a belt conveyor (19). The apparatus includes a sampler (28) movable across the conveyor belt (20) for segregating a cross-stream increment of bulk material (21) from the belt (20) and ejecting the sample into a collection chute (69) positioned adjacent the belt (20). The sampler (28) has a trapezoidal cross-section so that the surface area which it projects upstream of the bulk material flow is relatively small in comparison to its sample-accepting capacity. Preferably, the acute angle (44) is determined as a function of the anticipated rate of the sampler (28) across the belt (20) and the anticipated speed of the belt (20) while the sample is being taken so that the downstream plate (36) of the sampler (28) encounters no appreciable resistance to movement across the belt (20) by the bulk material and at the same time contributes to the maximizing of the volumetric capacity of the sampler (28). The system (18) also includes a surge dam (130) positioned upstream of the sampler (28) for limiting buildup of bulk material against the upstream side (40) of the sampler. Upon completion of an increment-collecting cycle, the sampler (28) is parked in a position relative to the opening (71) of the collection chute (69) so that ingress of bulk material into the chute opening (71) from the belt (20) is restricted by the sampler.</p> |
