Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie Number 01/2019

Devices with a flameproof enclosure are commonly used in mines in potentially explosive areas. These devices are equipped with appropriate cable entries. The user of the device chooses the cable glands. Many types of cable entries are available on the market, generally cable gland may be an equipment (marked with the X symbol) or may be an Ex component (marked with the U symbol). The user can install only cable entries that are assessed as equipment. It happens, however, that the selection of the cable gland is incorrect. The most common errors are mismatching the cable entry to the cable diameter and incorrect temperature selection. The same selection rules apply to blanking unused holes. Suitable blanking elements should be used. Temporary solutions, such as the use of non-original plugs, or the use of cable sections to close the flameproof enclosure, do not guarantee explosion protection. Paper presents the examples of not correct use of cable glands.

One of the mining systems used in Polish and Ukrainian hard coal mines includes a longwall system with plough longwall complexes. These complexes incorporate automation systems that make it possible to monitor and record operating parameters. The paper uses recorded pressure values of hydraulic legs of powered roof support sections, geomechanic parameters of rock mass, and the longwall advance speed in order to forecast the load of sections. Measurement data were obtained from complexes operating in the Lublin and Donets Coal Basin. To carry out statistical analyses, data grouping and multiple regression were used. The statistical analyses made it possible to determine the significance of individual model parameters and to make predictions of the expected section load. Even though various statistical analyses were used, the load values obtained correspond to actual loads. Further research on the use of operating parameters of longwall systems – in particular values of hydraulic leg pressure of powered roof support sections – may contribute to the increase in efficiency and safety. It may be conducted by drawing on previous experiences and obtaining new ones in terms of the selection of supports for geological and mining conditions.

The specificity of the Bełchatów lignite coal mine is determined by a close relationship with the operation of the power plant located nearby. As a result, it is necessary to ensure a stable supply of fuel in order to produce the assumed amounts of energy and, thus, it is required for mining machines and transport lines to operate without interruptions. In this respect, automation and monitoring systems intended for control and supervision of the power network in a mine are of major significance. The SYNDIS RV has been used in the Bełchatów lignite coal mine for several years. Given how useful the system has proven to be so far, it is difficult to overestimate its importance. The most notable effects of its use include improvements to work safety, elimination of incorrect reconnections, and remote control of several hundred objects located in the entire area of the mine. Applications that allow you to analyse network disturbances and correct its configuration are very useful. In addition, work support tools developed made it possible to limit the number of personnel and minimise the number of emergency shutdowns.