. A specific set of crushing rolls has rolls with a face width of 18 inches and a diameter of 45 inches. The crushing surface is split so that it is 1 inches apart at its narrowest point. The range recommended by the manufacturer is 80 to 100 rpm. A rock with a specific gravity of 2.35 * 10^3 is to be crushed by them. The nip has a 60 degree angle. If the real capacity is only 12% of the theoretical capacity, what is the largest feed size that can be used and the highest actual capacity in tonnes per hour?