Jaw Crushing Operation

Jaw Crushing Operation and Maintenance

Jaw Crushing Operation and Maintenance : 1. The jaw crusher should be greased and oiled regularly; this should be done prior to each use. To do this, simply turn all grease caps one full turn (clockwise) and put a few squirts of oil in both of the oil cups. If grease caps are tight, add more grease (see MAINTENENCE below).

2. Check jaws for cleanliness and clean them if needed. Loosen the wing nuts and remove the front shield, then loosen the hopper wing nuts (located below the hopper on the left and right of the machine) and move it up and back so that the jaw cam lock is exposed. Lift the cam lock up to release the stationary jaw so that it may be lifted straight out. If it is jammed, the cam lock may be freed by tapping lightly with a mallet or ball-peen hammer. Once the stationary jaw has been removed, the movable jaw will be exposed inside the machine. Brush both jaws with a large bristle brush. If any residual sample material adheres to the jaws, it may be removed by brushing with a large stainless steel bristle brush. After brushing, blow the jaws off with compressed air. The hopper and sample collection trays should not be brushed, but should be blown off with compressed air. Reassemble the jaws and put the sample hopper back in place, hand-tightening the wing-nuts and replace the front shield.

3. Adjustment of jaw spacing: Turn the circuit breaker (located in the breaker box) to the "ON" position. While the crusher is empty, start the machine and allow it to come up to full speed. The machine must be adjusted while running. Loosen the square-head bolt (left). This will allow the hand knob (or right) to turn. Slowly turn the hand-knob clockwise until the jaws of the crusher can be heard just touching each other, and then back off the hand knob (turn counter-clockwise) just slightly. Slowly begin to re-tighten the square-head locking bolt. As this is done, the clearance of the jaws will decrease and may become too close. If this happens back the hand knob off slightly. Repeat this process until the bolt can be tightened completely without significant tapping of the jaws. It may take some practice to do this properly. This procedure will set the machine to grind as fine as possible (approximately 3 to 5 mm particle size) without damage to the jaws. If larger particles are acceptable, jaw clearance may be set to more than the minimum distance.

4. Once the jaws have been set, place a clean sample collection tray under the machine to collect the crushed sample. If concerned about contamination of sample material by skin oils and/or perspiration, wear clean, powder free latex (or equivalent) gloves while handling the samples. When sample volumes permit, it is recommended that the machine be "pre-contaminated". This is done by processing a small amount of the sample to be crushed (thus coating the inner workings of the machine) and discarding the resultant product. This reduces the amount of sample contamination from the machine. The lower opening of the hopper is 2 3/8" x 4". This limits the size of material that may be crushed. If a sample is to big to fit easily through the opening, then it is too big for the machine to process and must be reduced by other means to an acceptable size. Once a sample passes through the lower hopper opening, it will be quickly crushed and the product will be forced out through the bottom of the machine into the sample collection tray.