Coal Age

MAY 2017

Coal Age Magazine - For more than 100 years, Coal Age has been the magazine that readers can trust for guidance and insight on this important industry.

Issue link: https://coal.epubxp.com/i/831105

Contents of this Issue

Navigation

Page 38 of 51

May 2017 www.coalage.com 37 plow mining continued coal mined by Bogdanka is used mainly for the generation of electric and thermal en- ergy as well as cement production. Lubelski W giel Bogdanka S.A. con- sists of three plants: Bogdanka, Nadrybie and Stefanów. The three plants are within a distance of a few miles and have a total of six shafts and one prep plant. Bogdanka started mining in 1975. The first coal from a longwall was mined in 1982. Since that time, Bogdanka mined more than 120 million tons of coal. For 30 years, Bogdanka based their underground mining operations on shearer technology. To reach those goals, Bogdanka select- ed plow technology and they have been using them for several years now. Through the implementation of plows, the mine now expects to reliably reach mining of 47-in. to 63-in. thickness. The application of this technology should improve the cost effectiveness of mining and significantly reduce the amount of dilution. The first plow longwall at Bogdanka was set up on the Nadrybie plant in the pan- el 1/VI/385 of seam 385/2. The length of the longwall was 820 ft, whereas the panel length was 5,740 ft. The mining operation on that panel commenced on March 25, 2010. The next panel with the first Bogdanka plow system was set up on the Stefanów plant. This panel with the description 7/ VII/385 had some important changes in comparison to the first, experimental panel. The face was widened from 820 ft to 1,000 ft and the panel length was approximately 3 times as long, i.e., 3.1 miles. The thickness of the seam in this field ranged from 47 in. to 63 in. The Longwall 7/VII/385 was launched at the beginning of October 2011. Another important change was the po- sitioning of the plow control station on the surface. The control station was set up in a special room in the Stefanów administra- tion building. In comparison to the plow control cabin placed in the energy train in the first panel, the control station on Ste- fanów was additionally equipped with a number of other monitoring systems. A control center plays an important role in achieving high production. The dispatcher's duty, along with the effective control of all plow systems, is to react as quickly as possible in case of any unsched- uled breakdowns. To act effectively, next to the longwall control the dispatcher has to have a direct access to all relevant monitor- ing systems such as power supply, pump stations for high pressure medium as well as for cooling and spraying water, convey- ors with bunkers and shaft, ventilation and methane control, material transport, etc. Having all this information at one glance, allows quick reaction in case of a stoppage. Consider that for a high-performance plow face, a one-minute break means a loss of 15 to 30 t, the importance of a quick reaction for unusual situations becomes obvious. The plow system in the second panel reached a production level of 11,000 tpd to 16,500 tpd raw relatively quickly. The daily running time of the plow increased in comparison to the first panel from 6 hours to more than 10 hours. This positive development results from the longer face width but also from conclusions drawn by Bogdanka from the first panel and the technical improvements implemented in the second panel. On February 16, 2012, Bogdanka broke the world production record for daily pro- duction from a plow-equipped longwall, with an output of 27,448 t of coal from the 7/VII/385 panel. The plow face advanced more than 88.6 ft that day at a 64-in. cut- ting height. The plow system mined in 2012 a total of 3.78 million tons. In the fourth quarter of 2012, a second plow system at the Nadrybie mine com- menced operation. It incorporates the technical solutions learned from the orig- inal. However, there are many important technical improvements in comparison to the first system at Nadrybie. Among other features, the following important differ- ences were implemented: • The plow uses asynchronous motors with 355/1,073-hp installed power in- stead of 282/846-hp motors used on the first system; • For the powering of the plow and the AFC motors, 3.3-kV liquid cooled four-quadrant VFDs are used; and • New, specially developed P45-CST (VM version) instead of P45-UEL gear boxes are used for driving the plow and the AFC. The medium voltage VFDs are built in and mounted in a flame proof enclosure using a pulse width modulated (PWM) cur- rent source inverter (CSI) for the machine side converter. VFDs of this type possess an effective power structure with a current lim- iting DC link inductor. The CSI VFD works Figure 9— In the face at Bogdanka II. Figure 8—Overhead discharge main drive at the Bogdanka mine.

Articles in this issue

Links on this page

Archives of this issue

view archives of Coal Age - MAY 2017