VDMA

JAN-FEB 2018

Best of Germany 2014 - Mining Equipment and Mining Technology

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VDMA 16 VDMA MINING SUPPLEMENT • 2018 When asked how often pumps are rejected once they reach the test bench, Hoffmann said, "Rejected? Never. The quality is moni- tored throughout the entire production process. If there is problem, it is rejected earlier in the chain. Once it reaches this test bench, it's an ISO-certified product." "Ruhrkohle AG has Hauhinco pumps that have run for more than 30 years without a problem," Hoffmann said. "We come from the underground mining sector and deliver products to the indus- trial sector, while most of our competitors come from the industrial sector and now also supply to underground mines." Hauhinco offers seven models for the mining business that range from the EHP-3K 75 to the EHP-5K 400, which would be five plungers, 400 kilowatts, 725 m 3 /min and 500 bar pressure. "The EHP-5K 400 is currently our largest pump and it is becoming very popular with the longwall mines," Durst said. "We have installed them in Russia, China and the USA." The pressure requirements in underground longwall mining have changed. "The new Russian longwalls need the power," Hoff- mann said. "Some Russian longwalls have as many as four or five 5K 400s for a single face." The company is modifying existing pumps and also developing entirely new plunger pumps and systems. "We have also improved the condition monitoring system," Hoffmann said. "Normally, we measure temperature, pressure and energy consumption. Now we can also measure vibration, which allows users to see problems de- veloping." Hauhinco has supplied more than 1,000 systems world- wide and it keeps $6 million in parts for pumps and valves in stock. They have air freight area ready to ship pumps, valves and spare parts anywhere at moment's notice. Six years ago, Hauhinco started to develop water treatment systems for underground mining. With this system, the company reacted to the concerns of mines and OEMs on the possible effects bad water quality can have on the entire longwall equipment. "We are working with water as a hydraulic medium and it's important to have a clean medium," Durst said. "Longwalls are a high capital ex- pense and coal companies want to make sure that they operate for a long time. Water is the blood of the system and it must be clean." A hydrocyclone filters solids from the water before it enters a three-step filtration process with a fineness-of-filtration of 100 microns (μm), 50 μm and 25 μm, and an automatic backwash. A 50-μm bag filter clarifies the returning water-HFA-emulsion from the longwall face. The water treatment system filters the impurities. Hauhinco asks the mine for a water quality analysis and they cus- tom design a treatment system to filter the water. "Miners are much more in tune with water quality," Hoffmann said. "Customers on the industrial side often take water quality for granted." The standard system converts 2,000 liters per hour (l/h) of water with a conduc- tivity of 1,990 micro-Siemens (μS) to 1,000 l/h of clean water with 19.5 μS. The system can be adapted to water characteristics and the required volumes of water. The main 6,000-l tank holds 5,000 l of water-HFA-emulsion and 1,000 l of HFA concentrate. An automatic emulsion-mixing system enriches the water with concentrate. Analog measurement devices in the HFA and concentrate compartment show the filling level. A transmitted light refractometer with a biprism monitors the emul- sion. "All of our pumps and components are running with HFA [97% water and 3% emulsion] or clear water," Hoffmann said. "Clear wa- ter is of course used for dust suppression." The high-pressure station is also equipped with two hydraulic accumulators that reduce pressure spikes and shocks. Two auto- matic high pressure double back-flush filters clean the mixture again before it leaves the high-pressure station for the roof sup- ports in the longwall. Mines in different parts of the world use different pump station designs. Hauhinco for example supplies high-pressure pump sta- tions and water spray stations mounted on crawler tracks through- out mines in Australia. Onboard the crawler track mounted pump station is a dual-shaft motor system with pumps on either end of the motor. A variety of pumps with different flow and pressure ap- plications can be suited to this system. This system was developed to ensure all equipment is located in the one high-pressure area and therefore simplify transport lo- gistics when only moving one piece of equipment in the mine. On the run, maintenance with minimal downtime can also be achieved with this design. "With the dual-shaft arrangement, one pump can be quickly disengaged without any hot works or additional labor re- quired to achieve this, then the other pump application can still be left in operation. General maintenance can be carried out or the pump can planned to be removed if required, therefore continuing operation reducing downtime and production. This design is very compact and mobile, but the mine also must have a minimum 2.2-m seam height to accommodate the dual shaft design on crawler tracks. The dual shaft application can be incorporated into a monorail mounted station or a transportable base sled design. However, gen- erally we can accommodate all types of configurations. Improving Longwall Productivity and Safety While the use of automation grows, Caterpillar Global Mining Europe GmbH, continues to develop new longwall system components that lend themselves to automation, such as its High Torque Drive system. The armoured face conveyor (AFC) drive system improves longwall performance by replacing traditional components with more efficient ones. Such evolving and new technologies, according to Cat, promise to drive longwall production higher and cost per ton lower while reduc- ing exposure of miners to health and safety hazards. Recent production results recorded during automation implemen- tation on a high-production Australian longwall illustrate the positive roll that automation can play. In brief, weekly production grew from 61,592 metric tons (mt) to 118,094 mt as automation grew from 0% to 98%. Production grew more than 90% as the use of automation increased, as indicated by shearer ranging arm override commands. Cat said it has found similar results at two other Australian longwall mines owned and operated by different mining companies. In the first case, the average time taken per shearer pass dropped from 56 minutes to 44 minutes as automation was imple- mented. The reduced travel time increased the average number of passes per week from 68 to 91. Hauhinco's water treatment system produces 1,000 l/h clean and salt-free water. The conductivity of the water is approximately 20 μ S after the treatment process and nearly salt-free.

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