The company in particular was keen to show customers its work in the development of cost-effective hybrid and plug-in electrification of plant drives, which it not only implements in new generation models and innovations, but consistently in all of its crushing, screening and handling solutions.
As part of its “e” (for electric) series portfolio in mobile crushers, Keestrack presented diesel-electric full hybrid plug-in models of its track-mounted jaw, impact and cone crushers. According to Keestrack, the new and enhanced models are not only suitable for 60- to 70-tonnes transport weight in terms of size, output, product quality and variety, but are also setting standards for cost-efficient operation with sophisticated drive concepts.
Without restrictions in portability and tracked on-site mobility, the diesel-electric heavy crusher range satisfies the requirements for volume-intensive recycling jobs on construction sites, plus multi-stage production of mineral aggregates in pits and quarries.
For the first time internationally, the 700 tonne per hour (tph) Keestrack B7e jaw crusher was unveiled. Replacing its predecessor, the B6e, the B7e’s core comprises a tried and tested CJ412 single jaw crusher, with a 1200mm x 830mm inlet for feeding sizes up to 700mm and a wide, hydraulically adjustable closed side setting (CSS) range of 75mm to 250mm.
In the B7e – only available as plug-in hybrid – the crusher is driven by a 132kW electric motor. Another 55kW electric motor powers the hydraulic system for the tracks, the lifting cylinders, the vibrating feeder with two-deck pre-screening and all conveyors.
The diesel-electric power is delivered by an on-board Volvo diesel engine (optional 273kW EU IIIa or 285 kW EU IV) and on-board 330kVA generator. The engine house is available in a detachable drop-off module, to be positioned away from the crusher, in a dust- and vibration-free environment.
Thanks to constant and low engine speeds, even under full diesel-electric load, the Keestrack B7e operates with low fuel consumption. According to Keestrack, energy-saving costs of up to 80 per cent can be obtained in emission-free plug-in operation from mains or external gen-sets. The plant, with a total weight of just below 69 tonnes (with options), is highly mobile; by detaching the 6m3 feeder unit, including pre-screen, the weight drops below 60 tonnes.
Complementing the B7e at bauma was the full hybrid Keestrack H6e cone crusher. The H6e offers high production capacities in the secondary and tertiary crushing phases. With a maximum feed size of 215mm, variable crushing chamber configurations and stroke settings (a CSS of 6mm to 44mm), the specially adapted Keestrack KT-H6 crusher, based on proven Sandvik technology, can process up to 400 tph of raw materials.
An optional three-deck post-screen module (with a 24.5m2 surface) with oversize recirculation provides high quality end products, thus guaranteeing high added value. The powerful e-motors for crusher drive, plant hydraulic (220kW/2 x 30kW) and all other directly electric-driven components are powered by a detachable diesel/generator module (345kW) or plug-in via mains or external gen-set. With a total weight of 62 tonnes with all options (51.5 tonnes without the final screen), the large cone can be operated economically at various jobsites.
This versatility is also a feature of the compact and highly mobile R6e impact crusher, with double pre-screening and double-deck post-screen modules, including oversize recirculation. Still available as a diesel-hydraulic as well as partially electric model with crusher direct drive (“rotor by diesel”), the R6e is a fully hybrid plug-in version (439kW). Despite its extensive electrification, including the 970mm x 1300mm crusher (250kW), the hydraulic system (2 x 55kW), and almost all conveyor drives and ancillary units, the 62-tonne plant can be flexibly dislocated with the optional dolly system.
The fully hybrid R3e impact crusher and the B3e jaw crusher were examples of Keestrack’s compact range of mobile units. The R3e, which was introduced in 2018, is fitted with a single-deck post-screen and oversize recirculation (total of 32 tonnes).
The 30-tonne B3e jaw crusher features a 1000mm x 600mm feed opening and accepts feed size up to 500mm. It can be fitted with an electric-driven double deck, with new independent pre-screen (1.6m2 + 1.2m2). The electrical equipment on the predominantly diesel-hydraulic plant includes a 42.5kVA generator for all conveyor drives and ancillaries and a 16A plug-out connection for downstream screens or stackers.
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Electric-driven screens
Compared to conventional diesel-hydraulic units, diesel-electric plants save up to 40 per cent of fuel. While working in production trains, the attributable fuel consumption may even decrease by 70 per cent when the hybrid screens are powered directly via the plug-out supply of an upstream or downstream diesel-electric crusher. To fully exploit this potential, Keestrack offers six models of its double-deck scalpers (250 tph to 1000 tph) as optional full hybrid plug-in versions.
New to the “e” program is the Scalper Keestrack K6e. With an 8m3 standard feeder and a 4500mm x 1800mm double-deck screenbox (2 x 8.1m2), the 30-tonne plant produces three fractions with 600 tph and can be adapted to a wide range of materials and applications with a variety of screen media and additional equipment.
A full hybrid screen solution with high potential for economical semi-stationary operation from the mains is the Keestrack K5e flip-flow screen (of about 29.5 tonnes). The specially adapted BIVITEC technology in the large double-deck screenbox provides a wide range of applications in the economic recycling of residual materials (eg glass, slag) or the processing of difficult materials with high basic moisture.
The flexible screening equipment also allows the efficient and economical production of minimum grain sizes of less than 2mm, handling hot materials (eg slag) or generally the production of large quantities of mineral standard products (up to 450 tph).
Solar-powered plant
Positioned close to possible power sources, stackers, with their rather low power requirements, are particularly suitable for economical alternative drives.
That is why Keestrack equipped its tracked stackers with diesel-electric plug-in drives at an early stage.
Brand new emission-free models in stockpile handling were presented in Munich. The semi-mobile electric S1e feeder/stacker is installed on a height-adjustable pedestal with lifting and 180-degree swivel hydraulics. The light 10.2m belt feeder (5.45 tonnes) conveys up to 280 tph of sand or gravel (a maximum size of 200mm) and creates kidney-shaped piles of maximum 2900 tonnes.
The S5e “solar” tracked stacker was also premiered at bauma. It is possibly the first directly solar-driven processing plant in the world, with photovoltaic modules mounted above the 23m long conveyor feed, and a 23kWh battery installed in the chassis. The battery powers all electric driving, lifting and conveying functions.
In case of bad weather or intensive continuous operation, the system can be powered or recharged via available external sources, such as upstream diesel-electric crushers and screens, or via mains plug-in.
There are two distributors of Keestrack plant and equipment in Australia: Screenmasters Australia (ACT, New South Wales, Queensland, Victoria and the Northern Territory) and Bost Group (South Australia and Western Australia).
Source: Keestrack