What's the external factors that affect the wire ropes service life?
1. Diameter ratio between drum and wire rope: In China, the friction lift design standard of diameter ratio is 1: 90 – 100 between Drum and wire rope, winding lift design standard is 1:80. While the international standard is usually greater than or equal to 1: 100. This will be helpful to reduce the damage to the bending of the wire rope. Domestic usually sacrifice D / d ratio to meet the requirements of breaking rally. However, foreign usually meet the breaking tension by improving the tensile strength and maintaining the D / d ratio. A large D / d ratio can greatly extend the life of the wire rope. D / d ratio 1:100 is the most cost-effective ratio of the wire rope use in friction hoisting.
2. Impact load: Many enterprises shorten coal loading time to achieve high efficiency and high yield. The increased coal loading caused impact and resonance on wire rope is another effecting factor to the rope life. The process of forming the resonance on the wire rope is greatly damaging. If we delay a few seconds during the coal loading, it can greatly reduce the impact and resonance, extend the service life of wire rope.
3. Storage and installation
Notes for wire rope storage:
- Wire rope should be stored in a dry and ventilated warehouse, to prevent direct sunlight or hot air baking, the warehouse can not stack multilayer wire rope.
- If the wire rope is stored in large quantities for a long time, it should always be checked to prevent rust. It should be promptly treated and re-coated with oil once rust was founded on the rope. If the corrosion is serious, the section of wire rope should be scrapping.
- If the wire rope stored in the outdoors, it should be placed on a dry ground, underlay with plant and covered with tarp.
Notes for wire rope installation:
- Brutal installation damage to wire rope: improper installation can cause fatal damage to the rope when installing a wire rope manually. And even lead to the whole rope scrapped.
- Improper installation of damage to wire rope: some enterprise adopt the way that new rope guiding the old rope for wire rope replacement. If the connection is improper, there would be invisible hazards when the old rope torque passed to the new one.
- The torque of the old wire rope would be release if we use rope connector for wire rope changes. Wire rope torque transmission and the other damages on wire ropes would be effectively resolved.
4. D/d radio between liner and rope groove: the nominal diameter (D) of the wire rope is not uniform with the diameter (d) of the friction liner rope groove. Domestic use of the past is the D / d ratio of 1: 0.9 ~ 1, British Burton's standard is 1: 1.1, Germany BECORIT company standards for the 1: 1.075. As the new rope diameter is usually nominal diameter of 1.02-1.05 times, in use, the rope wear to 90% of the nominal diameter only need to be replaced. With the ever-changing diameter of the wire rope, it is necessary to ensure that the desired proportion relationship is achieved by continuously turning the rope groove to maximize the protection of the wire rope.
5. Follow-up maintenance: greasing and de-greasing services.
6. Working environment:
- Water quality environment: Mine wellbore shower which affected by geology and wellbore equipment is generally acidic water. This water not only cause great corrosion to the wellbore equipment, but also the serious corrosion of the wire rope. Currently, many mines are lack of necessary maintenance on the wire rope, which greatly affected the rope life. Most of the LMA losses were severe and the wellbore shower was also large. In order to avoid corrosion damage to the wire rope, the best way is to strengthen the management of wellbore environment.
- Well depth: different depth, the selection of wire rope requirements are also different. The correct choice of wire rope can effectively extend the service life.
More than 750 meters deep mine, the best choice of circular strand twisted wire rope;
More than 1,000 meters deep mine, the best choice of circular composite twist to strengthen the core wire rope;
Above 1200 meters mine, it is recommended to use round bar to twist the stock to strengthen the core wire rope.