Productivity is one of the key facets to operating a successful quarry. In a bid to provide quarries and mines with technology that enhances throughput, a German OEM has crammed a lot of power into a compact eccentric roll crusher.
While some might argue the “if it ain’t broke don’t fix it” maxim to decades of conventional quarry machinery is applicable, industry demand for faster and more efficient technology has taken charge. thyssenkrupp’s eccentric roll crusher (ERC) aims to improve the capabilities of quarries by providing an innovative, advanced solution to hard rock crushing.
The ERC combines improved power, efficiency and size to provide an alternative to conventional gyratory and jaw crushers. The unit is available in five models: the ERC 18-14, ERC 20-20, ERC 25-25, ERC 25-30 and ERC 25-34. In the larger models, the feed opening into the crushing chamber is an average 2500mm wide and 1280mm high.
Suitable for hard rock crushing in both underground and surface operations, thyssenkrupp has engineered the ERC to provide a rock crushing solution that boosts productivity. The machine features an integrated grizzly that bypasses fine materials to help increase liner lifetime and capacity while reducing energy consumption. Capacities of up to 10,000 tonnes per hour are achievable with the integrated grizzly. Coarse material is crushed between the oscillating roll and jaw of the machine.
The ERC’s kinematic design allows the stroke to be equal throughout the entire crushing chamber. During the crushing process, the ERC is able to roll backwards to distribute the material over its entire circumference. thyssenkrupp engineered this to prevent uneven wear zones. As a result, the crusher’s kinematics provide high comminution intensity and high throughput rates.
The ERC has been designed to have a weight balance through its oscillating roll to avoid the risk of machine overloading. This reduces machine vibrations and loads, giving it the much needed benefit of use in mobile and semi-mobile crushing systems in quarries. The machine’s flywheel and V-belt pulleys have a significant inertia which reduces the amount of energy peaks needed during the comminution process.
Featuring a compact design not normally found on rock crushers, the ERC’s installation height has been reduced by between 20 and 50 per cent, compared to similar performing gyratory or jaw crusher options that require high headroom in confined spaces. Its smaller size and reduced number of components also assists with maintenance time and allows it to be transported around the site. This is achieved through the crusher’s removable hood that can be dismounted with ease.
The crusher also features a hydraulic gap/retraction system that reduces liner wear. This allows the swing jaw to be adjustable and adapted to suit a specific product. It features an adjustment range of up to 200 millimetres. Uncrushable materials, such as tramp metal, are expelled from the machine through this system which ensures the machine is robust and long-lasting.
The higher service life of the ERC’s wear elements and a reduction of energy peaks also improve its reliability. Machine stress is also reduced through the addition of balancing the rotating crushing element, resulting in low machine vibrations during a no-load operation. There is a notable amount of rigidity in the crusher’s design which allows it to have a strong resistance to large chunks of feed material. The chunks of sediment that are fed into the crushing chamber hit the hood, rather than falling on the natural element.
For all of its advanced features, thyssenkrupp has the numbers to prove its machine is a viable alternative to conventional crushers. The first prototype was tested in a German quarry in 2017 to test its ability to process operating parameters and data processing. The crusher then had an output greater than 2500 tonnes of hard andesite per hour during testing. This gives the ERC an advantage over conventional jaw crushers and even rivals the throughput of some gyratory crushers. The ERC’s power consumption was proven to be highly efficient in the test, achieving a power draw of 200 to 500 kilowatts, depending on speed and gap width variables.
With a significantly smaller footprint, thyssenkrupp has developed a machine that is not only portable but highly competitive and economical.