Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
Issue link: https://emj.epubxp.com/i/142836
DIESEL ENGINES increased the injection pressure and compression and reduced internal friction. Other features of the new engines include stable multiple injection, optimized combustion chamber geometry and efficient forced aspiration. Meanwhile, the common-rail principle ensures efficient, accurate fuel injection. Soot particles inside the combustion chambers are reduced to a minimum, with lower fuel consumption. Scania: Building on Road-vehicle Technology The Swedish engine and vehicle manufacturer, Scania, exhibited its 9-, 13- and 16-liter industrial engine families at bauma, all of which are ready for 2014. The three ranges offer power outputs of 202–294 kW, 257–405 kW and 404– 566 kW, respectively, with the 9-liter units based on a five-cylinder in-line format, the 13-liter as an in-line six, and the 16-liter as a compact V8. Each range features Scania's common-rail, extra-high-pressure XPI fuel injection, charge cooling, exhaustgas recirculation (EGR) and SCR. The difference from its previous engine ranges, which complied with Tier 4i/Stage IIIB, is the addition of EGR systems, the company said, while pointing out that each of the three engine ranges has the same installation dimensions irrespective of the emission level. Installation remains unaffected, it added, which significantly reduces the efforts required from OEMs that are active on the global market. Scania pointed out that its industrial engines have been developed in parallel with engines for trucks and buses, thereby complying with new emissions legislation several years before it takes effect. Clean, refined combustion technology means that it manages the very stringent Tier 4f/Stage IV regulations without the need for a particulate filter, the company having gained many years of experience with EGR and SCR from its trucks and buses. Scania's Tier 4f engine design includes EGR. (Photo courtesy of Scania) 48 E&MJ; • JULY 2013 Scania has also implemented a modular philosophy throughout its engine ranges. This greatly facilitates servicing, repairs and parts supply, since the engines all share the same cylinder design, the company said. They have cylinders with replaceable liners and many common moving parts. "If you know one Scania, you know them all, regardless of its configuration—in-line or V8," the company said. With EGR, a small amount of exhaust gas is returned to the engine intake, diluting the intake air and reducing the oxygen concentration. This reduces the combustion temperature and the emissions of both particulates and NOx. The main function of the SCR system, meanwhile, is to further reduce NOx emissions. SCR is based on the injection of a urea solution in the exhaust system, with solution consumption running at around 5% of fuel consumption for Tier 4f/Stage IV NOx levels. Cummins: New, Small Mining Engine At the smaller end of the mining engine range, Cummins launched a new Tier 4fcompliant 12-liter engine, the QSM12. However, some of its larger engines were also featured prominently at bauma. The two largest pieces of mining equipment on show in Munich, Liebherr's T264 truck and R9400 mining shovel, are both powered by Cummins engines, while Cummins exhibited its top-of-the-range 3,132-kW (4,200-hp) QSK95 mining diesel on its own stand. The company said the QSM12 provides a compact configuration and offers 382 kW (512 hp) peak output. This makes it suitable for powering equipment such as wheel loaders and excavators with a bucket capacity of up to 7 yd3, Cummins added, as well as for LHDs with capacities up to 20 tons. With a six-cylinder in-line configuration, the QSM12 provides more than 30% higher power density than the class average for engines with a similar power range, while meeting the new emission limits without the use of EGR, Cummins claimed. Instead, higher-efficiency air handling and advanced combustion enable it to return to the simplicity of a waste-gated turbocharger, then combining a diesel particulate filter (DPF) with SCR to achieve ultra-clean exhaust. "For Tier 4 Final, the QSM12 sets a new benchmark for heavy-duty engines with its ability to outperform any compara- Cummins QSM12. (Photo courtesy of Cummins) ble engine, while providing a smaller, lighter and simpler engine package to install," said Hugh Foden, executive director for Cummins Off-Highway Business. "The new QSM12 provides an ideal opportunity for equipment manufacturers to downsize to a far more productive and economic 12-liter engine, with all the heavy-duty durability and performance they need." The SCR system developed by Cummins for Tier 4fl/Stage IV is a nextgeneration design with a copper zeolitebased catalyst capable of more than 95% NOx conversion. Diesel exhaust fluid (DEF) dosing is minimized by the use of a highprecision injection spray pattern. When the cost of the DEF is combined with the cost of fuel consumed, the overall fluid operating cost of the Tier 4f QSM12 is lower than that of the previous Tier 4i QSX11.9 engine, the company claimed. The company said that its experience of integrating DPF and SCR technology as a single system is unmatched in the industry, with almost 450,000 Cummins engines produced with this combined after-treatment. Deutz: Opportunities to Down-size For old-timers in the mining industry, the name Deutz was synonymous with the aircooled diesels used in LHDs and other mobile equipment. Not any more—today the company offers a wide range of both air- and water-cooled units, and took the opportunity provided by bauma to launch its new generation of Tier 4f/Stage IV-compliant engines. These illustrate the current trends in innovative engine construction, Deutz said: adaptation to the latest emissions standards, downsizing and economy. www.e-mj.com