Finer and coarser particles separate and concentrate in different parts of the chamber. Typically, the coarser material accumulates at the top and the finer material at the bottom.
Material segregates when it hits a horizontal surface.
Vibrations increase segregation further.
Two conveyors feeding directly into crusher
Correct the feeding device. A feed box, splitter, hit plate or centring chute might solve the issue. In fine crushing applications, a divider can be used to spread the material in the feed hopper.
Horizontal segregation is difficult to correct with simple measures. A rotating feed distributor can be used, but it is usually simpler to correct the problem at an earlier stage of transportation.