Uncontrolled pushing force can lead to severe degradation of coke oven walls. To measure the pushing force a torque sensor can easily be installed on the driving shaft of the pushing machine.
The pushing curve shows a typical first peak which corresponds to the end of the coke cake compression phase and the beginning of the coke cake movement. Generally after this peak the pushing force sharply decreases as coke moves, coke weight decreases and oven taper prevents from wall friction.
The first peak is related to the coke cake properties.
Pushing curves may show a progressive increase of pushing force or further peaks depending on the pushing machine and the general condition of the oven.
Safe limit of pushing force first peak is around 1.5 times the coke weight.