Modeling coal discharge in mechanized steep and thick coal mining

Byakov²,

2018

The article considers the factors that directly influence the operation of the lip seals to seal the gap between the piston and the working cylinder in hydraulic props of mechanized supports, this directly affects the tightness of the props and, as a consequence, the safety of work in the production face. A description is given of these factors, which is supported by practical calculations obtained from the results of finite element modeling of lip seals of various designs at different pressures of the working fluid and sealed gaps. The problems of sealing rough surfaces with rubber-like materials are considered. The classification of these factors according to the degree of generalization and the functional interaction between each other is proposed.

Section: Introductionmentioning

confidence: 99%

Factors Determining Operation of Lip Seal in the Sealed Gap of the Hydraulic Props of Powered Supports

Byakov²,

2018

“…Mining roof support is a basic protection of underground mining excavations [1][2][3]. It covers the roof support of corridor workings [4][5][6] and the roof support of longwall workings.…”

Section: Introductionmentioning

confidence: 99%

Impact of geometry of the powered roof support section on the rock mass

Szurgacz

2018

The required functions of the powered roof support, the functions it must fulfil and the mechanical elements cause that the support practically continuously works with the rock mass. This applies to the canopy, the floor base and the shield support. Due to the different susceptibility and strength of the rocks, the roof support may lose its stability. This condition results in an uneven section load and difficulties with moving forward the support in the underground excavation. This, in turn, can lead to disturbances in the operation of the entire longwall system. In order to avoid this situation, it is necessary to conduct geometry tests, e.g. section tests for a dedicated testing station using innovative measuring inclinometers. They indicate the importance of proper geometry for proper and correct operation of the support section. The research was carried out with the use of a new methodology designed to test the geometry of powered roof supports. The solutions were developed by the author of the article.

“…Deteriorating conditions in the majority of mines in the world [2][3][4] cause that the powered roof support is increasingly exposed to dynamic loads. The size and characteristics of these burdens are not sufficiently recognized at present which increases difficulty in predicting the effects of such burdens.…”

Section: Introductionmentioning

confidence: 99%

Analysis of load of a powered roof support’s hydraulic leg

Szurgacz

Brodny

2018

The main purpose of the powered roof support is to protect headings from the impact of the rock mass. The result of such impact is static and dynamic load impacting the support section, which is carried by its construction. The basic elements of the construction of the support are hydraulic legs, whose task is to ensure adequate strength of its setting. Particularly in the case of dynamic impact of the rock mass, these legs are exposed to a very unfavourable load condition. Therefore, it is necessary to conduct tests to determine the parameters of operation for this type of loads. The paper presents the results of tests on the hydraulic leg subjected to impact load with free falling impact mass. The purpose of the research was to determine the parameters of the leg's operation, i.e. the time periods of pressure in the space under the piston and other elements of the hydraulic system. The tests were conducted in compliance with designed methodology and included innovative registration system. The obtained results clearly indicate the correctness of the adopted assumptions. According to the authors, the results should be applied during selection and operation of a powered roof support.