Influence of pipe roughness and coating built-up on pipe walls on the flow of solidifying Non-newtonian fly ash-water mixtures in hydraulic transport systems in coal mines

4th Polish Mining Congress-Session: Human and environment facing the challenges of mining

生态环境科学;矿业工程

Strozik, Grzegorz^1

Faculty of Mining and Geology, Silesian University of Technology, Akademicka 2, Gliwice

44-100, Poland^1

关键词: Corrosion process;    Hydraulic transport;    Mining operations;    Operation conditions;    Reliable assessment;    Rheological property;    Transport distances;    Underground technology;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/174/1/012015/pdf
DOI  :  10.1088/1755-1315/174/1/012015

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Due to favourable physical properties, the most frequently used fill materials in underground technologies are mixtures of fly ash from hard coal combustion and water. The mixtures are delivered by pipelines from the ground surface to the places of application gravitationally, so the reliable assessment of flow parameters is crucial for the successful fill operations. In first place rheological properties of mixtures must be known for further flow parameters prediction. These parameters may be obtained from measurements in laboratory pipeline loop, which reflect the operation conditions of industrial pipelines in terms of flow rate range and variability of rheological properties of mixtures. Further considerations focused on the problems of range of flow and influence of pipe roughness on reduction of mixture delivery distance. Among other, the conclusion is that the transport distance occurring with technologically acceptable flow rate decreases rapidly with increasing pipe roughness and may finally lead to pipeline failure. As it has been shown on an example to any point of mining operations may be delivered fill mixtures with a certain maximal value. This maximal density is varying widely in relation to actual length and height of gravitational pipeline. Flow parameters of fill mixtures in gravitational pipelines may be affected heavily by increasing of pipe roughness. Variability of absolute pipe roughness have been discussed in relation to typical abrasion and corrosion processes of pipe walls and also considering potential coating built-up created by solidified mixture layers. Operation of gravitational pipeline in systems of underground voids filing should be considered as a dynamic process, where the geometrical parameters and roughness of the pipeline may undergo continuous and rapid changes.