Doosan add power in Czech granite quarry

Increased performance of new Stage V DX350LC-7 tracked excavator key to heavy work with granite

A NEW Doosan DX350LC-7 Stage V-compliant excavator is delivering increased power and fuel efficiency working with heavy blocks of granite at Ruprechtice Quarry, one of several northern-Bohemia quarries owned and operated by Ligranit a.s.

The new machine was supplied by Garnea a.s., the authorized dealer for the Doosan range in the Czech Republic.

‘Over the last 10 years, quarrying has changed in terms of processing granite blocks,’ said Radek Svoboda, production manager at Ligranit. ‘Previously, everything was done by hand; today, it is mainly carried out with the latest machinery and technology.

‘We purchased the new Doosan machine for its power and low fuel consumption, but of course, the length of the warranties and the service from Garnea were important factors too.’

As well as exceeding the performance, fuel economy and environmental parameters set by Ligranit, another aspect that supported the purchase of the DX350LC-7 was the excellent service record of a smaller Doosan DX140LC-5 excavator owned by the company.

‘We negotiated with the management of Garnea and everything that was promised with the new DX350LC-7 has turned out exactly as they said,’ remarked Mr Svoboda.

The warranty protection on the DX350LC-7 model is three years/5,000 hours as standard, but thanks to the long-term relationship between the two companies, Garnea have agreed to extended warranty cover of five years/10,000 hours.

At Ruprechtice Quarry, excavators are brought into play after blasting work has finished, when stone blocks weighing from 100kg to 3,000kg are selected, the larger pieces being reduced in size by a hydraulic breaker.

Using an excavator, the blocks are then moved and further divided using a splitter. For more precise work, splitting is done manually, and where the potential for material quality is best, entire blocks are transported out of the quarry and worked on with a saw.

‘These blocks weigh between five and 15 tonnes, so the power of the new machine is a big plus for us,’ said Mr Svoboda.

To meet Stage V engine emission regulations, the new DX350LC-7 excavator is powered by the latest-generation Doosan DL08 diesel engine, which provides 209kW of power at 1,800 rev/min.

To exceed Stage V regulations without exhaust gas recirculation (EGR), the DL08 engine offers a new solution that boosts the quantity of air available during combustion, increasing the temperature of the process and greatly reducing the amount of particulates produced. This, combined with super-efficient DOC/DPF+SCR after-treatment technology, ensures minimal emissions.

Thanks to the new technology, maintenance of the diesel particulate filter (DPF) has been greatly reduced, with none required until the machine has operated for 8,000 hours.

With the DX350LC-7, Doosan say they have sought to ensure that productivity and environmental protection are truly compatible. The enhanced fuel efficiency of the DL08 engine in combination with a new hydraulic main valve and the new-generation SPC3 smart power controls, is said to provide overall fuel efficiency increases of more than 10% in S mode and more than 6% in P+ mode, compared with the previous-generation machine.