Choking a Crusher; Choke Feeding

Choking a crusher means a complete, or practically complete, stoppage of the downward flow of material in the crushing chamber. It may be the result of an external condition, such as a “back-up” of material occasioned by an obstruction in the discharge chute, in which case choking is followed by packing in the crushing chamber, Or choking may be the result of a condition existing within the crushing chamber, such as too close a discharge setting, too many fines in the feed, or sticky material. When so caused, packing proceeds –and brings about- the chokeup. 

Choke-feed implies a completely filled crushing chamber (or as full as the design will permit), with a sufficient head of material above the receiving opening to keep the crusher full continuously. This contrasts with regulated-feed, which implies that the flow of material to the crusher is throttled to a point somewhat below the capacity of the machine, so that the crusher is never completely filled.