The paper presents some practical approach to capacity (yeld) prediction of the basic technological machinery for processing operations: crushing, screening and conveying. All machines assumed as throughput devices, and its capacity (yeld) defined as the simple relationship Q = qP, wherein the output flow Q depends on the discharge opening surface of the flow rate q and surface of outlet opening P. The value of the machine opening surface P=Q0 /q at a given load Q0 of processing operation leads to the basic machine parameters, like width of the inlet, sieve size and the width of the conveyor belt.