Diesel electric jaw crusher offers compact transport and all-around production

At the MATEXPO in Belgium Keestrack presented the diesel electric B3e jaw crusher, a hybrid variant of its successful model deployed on building sites and recycling. All specific advantages of the track-mounted 30-tonne machine are preserved - budget-conscious operators can now benefit from lower maintenance costs and the opportunities for operating subsequently connected units cost-effectively.

Its extremely compact transport dimensions, low transport weight and state-of-the-art jaw, 1000x600-mm width, have enabled Keestrack to set real standards in recent years with the B3 (formerly "Argo") among 30-tonne jaw crushers. Even smaller exploitation operators appreciate the crushing capacity of the machine, which continuously delivers top-quality results of up to max. 300 t/h, thanks to gap widths of 45 - 170 mm (C.S.S.) that can be adjusted hydraulically at any time, the patented "non-stop system" with overload protection and innovative wear monitoring. Keestrack's B3, without support legs, has no trouble keeping up with the work on building sites and in quarries and, thanks to the robustly constructed tracks and the excellent chassis construction, it can also be deployed on challenging surfaces.

It is precisely these all-round characteristics, which have also made the machine very popular in the rental sector, and has prompted us to preserve these. At the introduction, the diesel electric Keestrack B3e has a similar crusher, heavy-duty vibrating primary screen and tracks drive are all diesel-hydraulically driven, and Keestrack's own load-sensing hydraulic control guarantees low consumption rates of the 160 kW Volvo diesel engine (tier 4f). With its main discharge conveyor, primary screen discharge conveyor or adjustable overband magnets (optional), partial electrification relates to those components, for which the electric drive realises actual fuel savings but above all improvements in both operational safety and maintenance costs. A compact, lightweight 42.5 kVA on-board generator supplies the power, which on the one hand further reduces the diesel operating speed (1500 rev./min), and on the other also reduces cooling requirements, risks of leakage and maintenance costs because the elimination of hydraulic motors and corresponding pipework. The reduced piping means that the Keestrack B3e now has 100 litres less hydraulic fluid, which pays off at every fluid change interval.

The Keestrack B3e offers direct fuel savings and operating cost advantages when driving a subsequently connected electrical screening unit (e.g. the Keestrack K2e) or a stockpile conveyor (connected load: 32 A (17.5 kW)). With merely 4 to 5 litres increased consumption in compound operations, Keestrack assesses that immediate benefits can be derived thanks to a higher added value through high-quality end-products or a clearly higher stockpiling capacity when operated by a single individual.

While the dimensions, weight and equipment are largely identical to the diesel-hydraulic system, Keestrack's hybrid B3e positions itself equally impressively as a profitable construction-site crusher for rapid relocation, even for small batches. For higher performance demands or operators with access to cost-effective electrical power, Keestrack is offering its new fully hybrid jaw crusher B4e (max. 49 t operating weight). In this case, a 110 kW electric motor is responsible for driving the 1100x700 mm crusher - and in addition an electrical 55 kW motor/pump unit powers all the hydraulic components (stroke and traction hydraulics). Similarly, the Keestrack B4e can be operated entirely from the mains supply, which Keestrack believes can achieve considerable savings in energy costs of up to 70 %. In mobile applications in the field, the on-board combination of 242 kW diesel engine and 225 kVA generator powers the machine, which provides a guarantee to the operator of full flexibility and high investment security on resale.