Reasonable control of the health of the vertical colloid mill

Complete Operating & Maintenance Guide for Vertical Mills: Startup, Running, and Long-Term Care

This guide ensures the safe, efficient operation and extended service life of your vertical mill. Please follow the detailed steps and best practices outlined below.

1. Pre-Startup Inspection
Complete these checks before powering on. This is critical for preventing mechanical failure:

• Mechanical Check: Rotate the mill manually to ensure the shaft turns smoothly without resistance. Inspect all pipeline joints and flanges for tightness.

• Lubrication System: Check the oil level in the bearing housing; ensure lubricant is filled to the indicated mark on the sight glass. Recommended Lubrication Interval: Change oil every 100 operating hours for the first month, then every 500 hours thereafter, or as strictly specified by the manufacturer.

2. Startup Preparation & Priming
Correct priming is essential to avoid cavitation and dry-running damage:

• Priming: Unscrew the water inlet plug on the pump casing. Fill the pump with clean water or the process slurry until liquid overflows from the plug opening, ensuring the cavity is completely filled.

• Valve Status: Confirm the outlet gate valve is fully closed. Ensure the outlet pressure gauge and inlet vacuum gauge valves are open.

• Electrical Check: Jog the motor to immediately verify its rotation direction matches the arrow indicated on the pump body (reverse rotation is strictly prohibited).

3. Normal Operation Procedure
Follow this sequence for smooth startup and loading:

• Startup: Start the motor. Allow it to reach rated speed and run smoothly.

• Building Pressure: Gradually open the outlet gate valve while closely monitoring the outlet pressure gauge and the motor amperage. Ensure the load remains within the normal range to prevent motor overload.

• Monitoring & Adjustment: Adjust the gate valve to reach the required operating point (flow and head) for your process. This point should be as close as possible to the pump's Best Efficiency Point (BEP), as indicated on the nameplate.

4. In-Process Monitoring & Key Parameters
Continuous monitoring is vital for safe operation:

• Bearing Temperature: The temperature rise of bearings should not exceed 35°C above ambient temperature, with a maximum absolute temperature of 80°C. Regular checks with an infrared thermometer are advised.

• Vibration & Noise: Operation should be smooth, free from abnormal vibration or harsh noises. If any occur, shut down immediately for inspection.

• Seal Condition: Adjust the packing gland to allow a drip leakage from the stuffing box (approx. 30-60 drops per minute) for adequate lubrication and cooling.

5. Shutdown Procedure & Winter Protection
A proper shutdown routine is equally important:

• Normal Shutdown: First, slowly close the outlet gate valve, then cut the power.

• Winterization/Frost Protection: After shutdown in freezing conditions, you must completely drain all residual medium from the pump and piping to prevent freezing and casing cracks.

• Long-Term Storage: For extended idleness, it is recommended to fully disassemble the pump, clean all parts, apply anti-rust grease to rotating surfaces (shaft, bearings), and reassemble before storage.

Core Operating Rules & Failure Prevention

• No Dry Running: Never start the pump without prime (liquid in the casing).

• Operate in the Efficient Range: Run the pump within the recommended flow and head range on the nameplate for optimal energy efficiency and minimal wear.

• Planned Maintenance: Regularly inspect the shaft sleeve for wear. Replace it promptly if deep grooves or eccentric wear are found.