Operation of Gyratory Crusher

3.6.1 Pre-operation Inspection

Before starting the crusher, a thorough inspection must be carried out. During the inspection, the main circuit switch must be pulled out. The inspection items are as follows: All connecting parts must be tightened and not loose; there must be no ore or any other objects in the crushing chamber; check the width of the discharge opening; check the interlocking devices with the equipment in the upstream and downstream processes. In addition, check the oil quantity and oil temperature in the tank. If the oil temperature is too low during cold seasons, use an electric heater to heat it. Check whether the lubrication equipment, the oil pump motor, and the crusher motor interlocking device are normal.

3.6.2 Starting Procedure

After the inspection confirms that preparations are satisfactory, close the main circuit switch and start according to the following procedure:

First, start the oil pump motor of the lubrication unit, and check and adjust the oil pressure. The oil pressure should be within the range of 0.08–0.15 MPa. Check whether the filter switch is correctly opened. Check the operation of the entire lubrication system based on the oil flow indicator, pressure gauge, etc. The water pressure in the filter should be 0.05 MPa lower than the oil pressure; otherwise, water may seep into the oil and cause an accident. After the lubricating oil has reached all lubrication points, give the starting signal as specified, and start the crusher. Run the crusher idling for 3–5 minutes. After the machine reaches normal speed, start the feeder to begin crushing operation.

3.6.3 Operation Precautions

After the crusher enters normal crushing operation, the operator must observe and pay attention to the following:

Check the operation of the crusher; there should be no abnormal knocking sounds inside. If there are any unusual noises or any abnormal conditions, deal with them immediately. In special cases, stop the machine immediately. The feed size shall not exceed 0.8 times the feed opening size. The discharge chute and the lower part of the crushing cone shall not be blocked by ore; otherwise, the ore may lift the crushing cone, allowing ore fines to enter the eccentric bushing and cause an accident. Pay attention to the operation of the oil pump, and frequently check the oil flow indicators, oil temperature, oil pressure readings, etc., at various points. The oil temperature after passing through the cooler shall not exceed 45–53°C. The return oil temperature shall not exceed 70°C. Supply oil to the upper suspension device on schedule. Check the tension and breakage of the V-belts, and ensure that the belts do not get greasy. If an accident occurs during operation, such as the chute being blocked by ore, oil supply stopping, oil temperature exceeding 70°C, or knocking sounds from the bevel gears, stop the machine immediately according to the prescribed procedure. Frequently check whether the connecting pins between the spider, the middle frame, and the base are loose, and whether the 15 mm circumferential gap is uniform. Check whether the liners at various parts are loose, missing, or severely worn. Strictly inspect the feeding condition to effectively prevent non-crushable objects (such as metal blocks, drill bits, etc.) from entering the crushing chamber.

The shutdown sequence of the crusher should be: first stop the feeding to the crusher; only after all ore in the crushing chamber has been discharged may the crusher be stopped; then stop the conveyor.

3.6.4 Adjustment of the Discharge Opening

After the crushing cone or the frame liner wears, to ensure the product particle size, the original discharge opening width needs to be restored. The method of restoration is to raise the crushing cone to reduce the discharge opening. If the crushing cone has already been raised to its highest point and the discharge opening still cannot be restored to its original width, then the only options are to replace the frame liner or the crushing cone liner, or replace both simultaneously.

When raising the crushing cone, first remove the nut on the spider, then screw the lifting ring into the threaded hole at the upper end of the main shaft of the crushing cone, and then use a crane to lift the crushing cone. Lift it to a height 5–15 mm higher than the pre-calculated distance it should be raised.

After the crushing cone has been lifted, turn screw 2 downward (see Figure 3-14) to press down the pressure sleeve 4 and the tapered sleeve 5. Then turn screw 2 back. Next, remove key 1 and turn nut 3 downward until it contacts the pressure sleeve 4. Then measure the discharge opening width. If it has not yet reached the required width, lift the crushing cone again and repeat the above procedure until the desired discharge opening width is achieved. Then drive key 1 back in and remove the lifting ring. Afterwards, clean the area, fill with lubricating oil, and finally install the cap.

Figure 3-14 Schematic diagram of discharge opening adjustment (Figure not provided in text; description: 1—Key, 2—Screw, 3—Nut, 4—Pressure sleeve, 5—Tapered sleeve)

Fig. 3-14 Discharge opening adjusting device

1—Key
2—Screw
3—Nut
4—Outer sleeve
5—Conical sleeve (or Tapered sleeve)
6—Fixed sleeve

Faults and Handling Methods
The faults occurring during the operation of the gyratory crusher, along with their causes and elimination methods, are listed in Table 3-6.

Continued Table 3-6