OPTIMIZATION OF THE DESIGN OF SUBSOILING AND PRESSURIZED FLUID INJECTION EQUIPMENT

There are 2 different design objectives for subsoilers with pressurize d fluid injection, for use as pan-breakers or injectors, respectively. A large soil failure is desirable when a subsoiler is used as a pan-b reaker and minimal soil failure is preferable when it is used as an in jector. This paper determines the optimum shapes of a pan-breaker and injector, where the draught can be reduced by injecting pressurized ai r (about 1.2 MPa at the air tank) from a nozzle port at the tip of the chisel. The results show that the optimum pan-breaker with fluid inje ction should have a rake angle of 45 to 600, a chisel thickness of 50 x 50 mm, and a heel position at 100 mm. The optimum injector with flui d injection should have a rake angle of 90 degrees, a shank thickness of less than 15 mm, a chisel length of 250 mm, a chisel thickness of 3 0 x 30 mm, and a heel position at 100 mm.