5. Ensure the feed is not segregated. All incoming feed material should be well mixed and homogeneous. A segregated feed condition exists when large stones are directed to one side of the crushing cavity and small stones are directed to the opposite side.
The side of the crusher receiving the small stones will have a higher-than-normal bulk density, and this can lead to something known as “packing” or “pancaking.” This in turn leads to adjustment ring movement on the side of the crusher receiving the smaller feed stones. Adjustment ring movement forces the operator to open the crusher setting to avoid this overload condition. This results in the production of oversized product due to the increase in crusher setting. In addition, segregated feeding and the resultant adjustment ring movement can lead to a tilted adjustment ring, resulting in larger loss of productivity.
6. Minimize surge loading for a more efficient circuit. Surge loading of any crusher is a “production enemy.” Surge piles or feed hoppers, along with variable-speed feeding devices, can be used to provide a better and more consistent feed control to the crusher. This allows the operator to run the crusher at a very consistent cavity level for extended periods of time. Providing better crusher feed control for the cone crusher through the use of surge piles, hoppers and variable-speed feeding devices such as belt conveyors or vibrating pan feeders can easily increase crusher productivity by a minimum of 10 percent.
7. Understand the design limitations of the cone crusher. Every cone crusher has three design limitations. These are the volume limit, the horsepower limit and the crushing force limit.
Regarding the volume limit, each crushing cavity has a volumetric limit that determines maximum throughput, and a choke-fed crusher is operating at its volumetric limit. The volume limit is exceeded when feed material overflows the top of the crusher. As for the horsepower limit, each crusher has been designed to operate at maximum power draw, and power draw will increase as the feed rate increases and as the feed material is crushed finer. The horsepower limit is exceeded when the crusher draws more power than it is rated for.
Lastly, don’t forget about the crushing force limit of the crusher. As with the horsepower limit, crushing forces being applied between the mantle and bowl liner increase as the feed rate increases, and as the feed material is crushed finer. The crushing force limit of the crusher is exceeded when the adjustment ring bounces, wiggles or moves on top of the main frame.
An ideal operational condition exists when the crusher is operating at its volumetric limit while still being slightly below both the horsepower limit and crushing force limit. Operating any crusher outside of its designed parameters with either excessive power draw or excessive crushing force results in a very serious crusher overload. These overloads create something known as “fatigue damage,” which is permanent, irreversible and cumulative. Without a doubt, frequent overloads will shorten the life cycle of any cone crusher.