The EV hammer crusher has been the preferred choice for raw material crushing at cement plants for many years. A billion tonnes of limestone has been crushed by this grand old machine. And now it is joined by a little brother.
The new crusher family member
The FLSmidth STRIKE-BAR crusher is the newest member of the FLSmidth crusher family and a perfect match to the EV™ crusher. The STRIKE-BAR is a horizontal impact crusher for raw material crushing and, at first glance, it looks sturdy and heavy duty – and a bit similar to the EV.
The two machines certainly share some familiar features, but the skin deceives and a peek under the hood reveals the differences.
Crushing raw materials for cement presents a number of challenges, and it is important to select the right crusher for the job. Limestone comes in many forms and can exhibit different physical properties that causes varying degrees of wear of the machinery. Other factors to consider include the required reduction ratio and the size requirements of the end product. This is where a broad panel of crushers makes sense. At FLSmidth’s in-house test facilities, the correct material properties can be determined and the appropriate crusher selected.
FLSmidth EV Hammer Impact Crusher
The working principle
The main area of difference between the STRIKE-BAR crusher and the EV is the impact zone.
On traditional hammer crushers, the main impact occurs between a pivoting hammer, rock and a fixed breaker plate. The final crushing occurs between hammer and grate. The STRIKE-BAR crusher utilises the similar high-speed impact, but the main impact occurs between a fixed bar, rock and ‘flexible’ breaker plates.
In machinery operating at such high speeds and impact forces, flexibility in the system is a must and it is of course an integrated part of both the STRIKE-BAR crusher and the EV.
FLSmidth STRIKE-BAR crusher
The EV utilises the fixed grate for fine crushing or grinding, making it suitable for high reduction ratios and small output (such as for a ball mill feed). The STRIKE-BAR crusher utilises several flexible breaker plates for crushing making it the right choice for medium course output (for example on vertical roller mills), easy wear adjustment and more flexible output size.
In machinery operating at such high speeds and impact forces, flexibility in the system is a must and it is of course an integrated part of both the STRIKE-BAR crusher and the EV - Henrik Sørensen
The main crusher at a cement plant is the first machine in the process. This crusher processes heavy quarry boulders weighing up to five tonnes each and reduces them to mill-feed size. This kind of operation demands an extremely durable crusher. But no machine can perform endlessly under such circumstances; hence the crusher must be flexible from the perspective of wear compensation, maintenance and replacement of wear parts. It is important that crushers have several inspection hatches for easy regular inspection and to enable free access above the rotor and breaker plates when major overhauls are needed. This is just one of the features that makes maintenance simpler and more cost-effective. Others include bolted-on wear segments, adjustable breaker plates, minimal use of different spare parts and chrome/manganese wear parts.
All of these challenges have been solved in the design of the STRIKE-BAR crusher, which is based on many years’ operational experience gained from the EV crusher.