Operate at a consistent closed-side discharge setting (CSS)
In order to gain a consistent aggregate quality, quantity and uniformity and achieve a balanced circuit, employees should operate cone crusher at a consistent closed side discharge setting. It will result in less production and more over-sized aggregate, if the crusher is operated at a wider-than-optimum setting, even if done only temporarily. In addition, over-sized product almost always causes issues in the circuit flow.
An example regarding the effect that crusher setting has on the product gradation is as follows, if the target crusher setting is 3/8 in. (10mm) yet the setting is not checked and it wears open to 1/2 in. (13mm), then the end result is a 15 percent decrease in the minus 3/8-in. (10mm) material size. There is a significant decrease in cone crusher productivity. If crushers are not being operated at consistent close side settings, many aggregate producers lose some of their revenue – and the size of the amount could really surprise them. Therefore, it is good to check the crusher’s setting on a per shift basis.
Operate at a consistent “choke fed” cavity level
The product will have an inconsistent shape and the production rate will be inconsistent, if the crusher is being operated at different cavity levels during the shift. When operating at a low cavity level, also known as half cavity, the product gradation will be much coarser. This level makes the product particles flatter and more elongated. A proper choke-fed cavity level should be pursued as it will increase crusher throughput tonnage and result in a more cubical product – especially with tertiary (short head) crushers that make the most of the producers’ salable products.
Avoid trickle feeding the crusher
Try not to trickle feed a cone crusher. In addition to causing poor cone crusher productivity and product shape, trickle feeding has an impact on bearing alignment within said crusher. A crusher should be operated above 40% but below 100% rated horsepower in order to maximize cone crusher productivity and to have a proper “loaded bearing alignment”. An optimal power range is to operate between 75%-95%. Operating a crusher above 110% rated power can cause premature crusher failure.
Make sure the feed is evenly and vertically distributed
Try to direct the incoming feed material so that it is distributed vertically into the center of the crusher. This will ensure that all sides of the crushing cavity remain evenly filled. If the feed is directed somewhere else other than the center, it will cause over-sized product, more flat and elongated product particles and a low crusher throughput tonnage.
In this situation, the operator will typically tighten the crusher setting in an attempt to produce a smaller product size, which can cause an over-load in the form of adjustment ring movement on the side that is heavily loaded. Over time, in this condition the adjustment ring can become tilted on the main frame and it can cause a bigger loss in productivity. With correct feed distribution, maximum crusher capacity, more consistent product uniformity, significant reduction of the adjustment ring action, minimum pressure on the bearings, reduction in energy consumption and even wear of the liner can be reached.