High energy, more acceleration for new screen market entry

Rocktec Australia has formed an agreement with International Combustion (India) Ltd (IC) for sales and distribution of the latter?s extensive range of process equipment. IC was established in India in 1936, initially as a division of a UK parent company and has operated in its own right, as a fully Indian owned company, since 1974. IC manufactures a comprehensive variety of vibrating equipment, built to the highest standards, which can be attested to by its long associations with companies such as Ecutec, Raymond, Mogensen, Schenck, Omni and Bauer. IC also manufactures crushing and milling equipment, air separators and associated plant, all of which Rocktec will be able to provide.

The vibrating equipment includes a comprehensive range of feeders, conventional linear and circular motion screens and the innovative and multi-function high energy Omniscreen. Complementing many of these designs are the IC linear exciters and out-of-balance motors.

Rocktec says that, with the ranges available, it can handle any feeding and screening application.

DISTINCTIVE VIBRATING ASSEMBLY

The patented Omniscreen is seen as representing the future within the mining and quarrying sectors, with its unique vibrating assembly and modular concepts, which have resulted in a linear movement screen that can operate at substantially higher acceleration, providing unparalleled flexibility and screening efficiency, when compared with conventional screens.

Each module can be individually fine tuned to provide acceleration, to maximise screening capacity and efficiency, eliminate blinding, reduce recirculation loads and minimise degradation. Wet or dry, OmniScreen offers a superior performance. The compact and incredibly rigid assembly is a simple solution to contain the lateral tension and compression forces, and is all located outside of the screen body, with the vibrators fitted to an independent self-supporting, strong frame, with the screen body attached to this frame. The result is the elimination of wear problems, reduced downtime and enhanced service life. The structure is extremely robust and free of fatigue and dynamic loads to the screen side plates are completely eliminated, as the vibrating mechanism is an independent component.

The construction of the screen frame itself is equally well engineered and manufactured to provide many years of reliable operations, using large and heavy-duty interconnecting pipes and a diamond pattern of bracings to provide strong structural integrity.

This unique design enables Omniscreens to run continuously at up to 7g acceleration if required. Particularly difficult or sticky applications can have intermittent acceleration up to 10g with the addition of an inverter variable speed drive. The result is high efficiency and capacity within a compact configuration; utilisation of available area can be up to 20 per cent greater than conventional screen types.

The modular concept enables units to be run with two or three modules operating in series, and they can be arranged as horizontal, inclined, or multi-slope configurations or in a combination thereof, as well as upwardly inclined as dewatering screens. The design enables the screens to be mounted at any angle between -5? and 30? to suit the duty, be it scalping, classification/sizing, washing or dewatering.

The large screen deck area, unrestricted by any drive mechanism, together with the screening motion and integral sub-frame, yields additional benefits such as lower costs for supporting structure, ease of installation, low power and maintenance costs throughout the long life of the screen, all contributing to increased reliability and profit. The absence of any restrictions between the decks, combined with generous free space between the decks, permits easy access for checking and replacing worn screen media, safely and hindrance free.

The design of the Omniscreen originated via Omni Crushing and Screening Ltd from Brazil, and has been improved and enhanced over the years using a combination of Finite Element Analysis, intensive studies of resonance and frequencies, in-house as well as on-site, as well as feedback from hundreds of Omniscreens in continuous and long term service. As testament to this is the fact that almost every Omniscreen ever built is still in operation. Rocktec firmly believes that these attributes have contributed enormously to the success of the Omniscreen and why it considers the machine to be the perfect selection for the Australian market, demanding, as it does, quality, reliability and efficiency, with economical investment and operation.

MECHANICAL SIMPLICITY

While great emphasis has been placed on the design, it has also been a priority to maintain mechanical simplicity. The actual vibrating assemblies are connected to electric motors via cardan shafts and affixed to massive side members outside of the screen frame and at 45? to the deck. The contra-rotating motors self-synchronise and the driven shafts are of relatively small diameter and short length, thereby avoiding any high stress or load issues. They are supported within self-aligning roller bearings (FAG or SKF). Adjustment, or tuning, of the screen acceleration is extremely simple; using a series of seven clearly defined settings on the vibrator weights, tuning can be accomplished within just a few minutes. Guarding of moving parts is also effective and simple, due to the compact drive assembly.

The modules are available in widths of 1500mm to 3000mm in 300mm increments, and lengths of 2000mm to 9000mm in 600mm increments, as single, two, three and four deck machines, and up to six decks for special applications.

The dewatering version, also run at high speed and high acceleration, reduces moisture content to below 10 per cent, thereby eliminating humidity segregation within the stockpiles.

Omniscreens can be configured to suit any type of screen media including wire mesh, steel plate, polyurethane, rubber and using any type of mounting and/or tensioning. They have been successfully used in a wide diversity of applications worldwide, including sand and gravel, all types of aggregate processing in the quarrying industry, iron ore, coal washing and separation, various high value ores, phosphates, clay/brick processing and slag sizing, for many years.

The Omniscreen design is ground-breaking in screening technology and Rocktec anticipates that the screen will gain popularity quickly, for both quarrying and mining applications, within Australasia and South East Asia, where Rocktec is concentrating its efforts.

Source: Rocktec Australia