Best of Germany 2014 - Mining Equipment and Mining Technology
Issue link: http://vdma.epubxp.com/i/743622
2016 • VDMA MINING SUPPLEMENT VDMA 21 Perfect Flow Control Focusing on smooth pump operations, KAMAT has recently redesigned its range of 80 kW to 400 kW three-plunger pumps. An emphasis was placed on minimizing noise and vibration, while retaining the advantages of the earlier design. That way miners can also continue to use the KA- MAT wear parts they have in stock at the warehouse. In addition to the modernization of the existing product range, the company significantly extended the range of pumps to bigger power in- puts with the development of five-plunger pumps. Here again maintain- ing the target of smooth operation but at bigger flows. Two Quintuplex pumps rated at 530 kW (max.) and 800 kW (max.) named K50000M-5G and K80000M-5G are already available. A new K120000M-5G for an im- pressive 1,200-kW input power per pump is currently being engineered and developed. Modern high-production longwalls with fast cutting shearers demand increasingly greater flows of longwall fluid. Previously, this has been achieved by adding more and more small or mid-sized pumps, which has led to increasingly complex pump stations. The disadvantage for complex pumps stations is operational reliability. A more reliable solution for high production longwalls with big flow de- mands is to use fewer, large KAMAT pumps. Using bigger pumps means a less complex pumping system. Logically this reflects in less probability of failure, less service, less maintenance, etc. Using big KAMAT pumps leads to much simpler installations, which reduce the associated hydrau- lic and electrical components. In most cases it also eliminates the need for suction boost pumps. The pump station is simpler and as such much more reliable. For longwall operations, the K50000M-5G delivers 640 l/min at 420 bar or 763 l/min at 360 bar. The K80000M-5G delivers 1,185 /min at 420 bar or 1,360 l/min at 375 bar. This means that the longwall can be powered by only one or two pumps. Big pumps producing big flows increase the demand for flow control. Thus, KAMAT also launched a new range of fail-safe smooth-acting un- loading valves for flows up to 1,500 l/min per pump at 500 bar (max). Since the experience with the lifetime of the solid ceramic plungers used for KAMAT pumps have been so positive, the recently introduced wear-resistant ceramic inner parts of the KAMAT unloader increase the liftetime of the wearing parts in the valve significantly. An unloading valve has to act quickly to control and limit the pres- sure in the delivery line to the face reliably. This requirement leads to pressure shocks in the hydraulic system—increasingly with bigger flows. Just as it pioneered the big flow pumps in coal mines, KAMAT has been pioneering the introduction of variable speed drives (VSDs) for longwall pump stations. Numerous KAMAT installations in the world prove the fact that driving a longwall pump with a VSD-drive significantly reduc- es service necessity and increases availability impressively. The VSD eliminates pressure shocks by adjusting the pumps drive speed to the flow demand of the longwall without the need for the unloader valve to switch. In periods of high demand, the pump operates at full speed and flow. If the demand is dropping, the speed of the pump is slowed down and adjusted to the need of the face. The range of controllability of the speed of a KAMAT pump is unique: typically the pump is able to be slowed down to 20% of the nominal speed and flow, in some cases even down to 10%. Running a K50000- 5G to supply a face at the typical 350-380 bar with a VSD-driven motor thus allows a flow spread of 640 l/min at full speed down to 130 l/min without the need to switch the unloader valve—and without the need for a booster pump. For years, the now-closed Kellingley Colliery in the U.K. operated its longwall on a single K50055M-5G delivering 640 l/min on a VSD-drive, without a booster pump. This is the simplest and easiest way to run a longwall, according to KAMAT. The big pumps have a surprisingly small footprint and are still relatively easy to handle underground. Systems built with the K80000M-5G with even higher flow, will not be wider than 1,600 mm. One VSD driven pump is enough to ensure any flow demand of the face. The use of only one VSD-drive in the system also reduces capital investment in the system. Should the longwall maximum flow require the installation of more pumps, these can be driven directly on line thus delivering nominal flow at full speed. While the longwall flow adjustments are managed by the VSD-driven pump, precisely to the demand of the face. Modern KAMAT-systems are equipped with one to three big pumps without booster pumps, controlled by a single VFD-drive. Unproductive stand-by capacities decrease or are eliminated. The system has high availability, minimal maintenance requirements, servicing well the needs of the highest producing modern longwalls. Together with KamDos, the automatic emulsion-quality measuring and dosing system, KAMAT of- fers their longwall pump station to meet all increasing demands of mod- ern high-output longwalls internationally. The 530-kW KAMAT K50000M-5G Quintuplex pump delivers 640 l/min at 420 bars for longwall operations. Next Generation Hoisting Technology Underground coal and hard rock mines differ in many ways. Whereas hoist- ing from 3,000 m or more is required in some metallic ore mines, the demand for high capacities is largely driven by the coal industry. In the long history of mining, SIEMAG TECBERG has often introduced cutting-edge technology by advancing design and development of hoisting. Now, in addition to the increasing demands, the industry is embracing new social responsibility policies with much more emphasis on work- place safety and working conditions. Technology can be used to isolate the miner from danger. For hoist applications, traditional guards and isolation techniques are no longer adequate and innovations such as mechanical rope handling equipment and higher levels of safety integrity in the equipment design are required. "Energy utilization is optimized nowadays using AC drives and highly efficient converters," said Detlef Scheppe, executive vice president for the hoisting technology business unit at SIEMAG TECBERG. "Friction winders can be further optimized by using the innovation of an integrated motor built into the winder drum. Its high mechanical rigidity supports an optimized motor design apart from being a very compact solution with several benefits to foundation and hoisting tower construction."