Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/548151
27 AGGREGATES MANAGER August 2015 EQUIPMENT MANAGEMENT Training: • Proper training for consistent maintenance is one of the most fundamental requirements for successful, reli- able production. Begin with the crusher's operation and maintenance manual. Incorporate the manual's suggested routine maintenance schedule into the maintenance team's duties. Appoint a "lead person" for each crusher as the go-to for that machine. This per- son is the historian for the unique operational adjust- ments the producer has incorporated for raw feed and product requirements. Daily log (document the following every 8 hours): • Amperage draw: See if it changes from day to day. If am- perage is exceeding normal levels, it could be a signal of bearing problems, loose belts, or general feed issues. • Coast-down time: You're going to need to know (and log) how long it takes the machine to come to a com- plete stop after shutdown. Here's why: If the time starts to shorten, this could indicate a bearing problem. • Oil pressure: You'll want to record performance in a variety of operating conditions. This will allow you to identify trends and help to detect problems before they cause costly damage or downtime. Daily maintenance (every 8 hours): • Check oil level, sight glass, grease appearance, and other lubrication schedules. • Check high temperature or low hydraulic pressure indi- cators and switches. • Check wear parts. • Tighten bolts. • Inspect belts. • Remove dirt and debris from crusher frame surfaces and areas around the machine. • Check intake/discharge chutes for any obstructions and/or build up. • Check alarms. If electrical changes are made or pro- grams are altered in automated systems, verify that all alarms and interlocks function properly. Don't be afraid to replace switches or timers that appear damaged or are in poor condition. This is more economical than a major overhaul, but never disable or alter any alarms or interlocks! Lubrication: • Completely drain and thoroughly clean out the inside of the oil tank (if you have one) to eliminate any con- taminants before refilling. • Find contaminant sources. Contaminants such as dust particles and water can get in where oil leaks out. • Inspect hydraulic systems and tag any leaks for correc- tive action on the very next maintenance cycle. • Use the proper grade of oil. • Use the proper specification of filters. • Keep the oil breathers clean. • Understand grease versus oil lubrication. Grease re- quires less-intensive maintenance than that of oil- lubricated systems. Automatic oil lubrication systems or sealed cartridge bearings are for higher speed crushers like vertical shaft impactors, air swept fine grinders, or high-speed cage mills. Most horizontal shaft impactors, hammer mills, and cage mill applications are below 1,000 rpm and grease is sufficient. • Maintain a scheduled oil sampling program. By creating a baseline of normal wear, it helps indicate when abnormal wear or contamination is occurring. The exact condition of a mechanical assembly is reflected in the oil. Belts: • Inspect V-belt drives for damaged belts or loose belt tension. By replacing cracked, glazed, torn, or sepa- rated belts, plus maintaining proper belt tension, you'll optimize your plant's performance. Wear parts: • Don't overextend wear parts. Avoid running them so long that they become too worn. You may find that you can no longer rotate breaker bars or interchange wear plates to lower wear areas — and now, you've lost half of the wear. Guards: • Rubber and chain curtains located in the feed and dis- charge openings of the crusher are subject to wear and tear. Since they are a first line of protection, it's impor- tant to inspect them regularly and to establish a sched- ule of regular maintenance.