Type of Document Dissertation Author Konduri, Indu Mohan URN etd-06062008-152159 Title Flow characteristics of jet fans in mines :experimental and numerical modeling Degree PhD Department Mining and Minerals Engineering Advisory Committee
Advisor Name Title McPherson, Malcolm J. Committee Chair Goodman, Gerritt V. R. Committee Member Hajj, Muhammad R. Committee Member Karfakis, Mario G. Committee Member Topuz, Ertugrul Committee Member Keywords
- confined jets
- fluid jets
- jet fan design
Date of Defense 1996-12-05 Availability restricted Abstract
The use of induction fans for face ventilation in room and pillar mines has proved to be an efficient, flexible, and viable technique. In addition to their merits over conventional systems, induction fans enable remote controlled mine operations with low maintenance requirements. Theoretical investigations were conducted initially to verify the potential of free air jets in mine ventilation.
A laboratory model using water as the fluid medium was designed to study the flow characteristics of a jet fan in a blind entry. The model was tested in a variety of brattice curtain and nozzle combinations to investigate the ventilating efficiency of jet fans. A jet fan was selected and tested in a full scale model and in a coal mine. Experiments were conducted to evaluate the laboratory flow models. Flow quantities and velocities in the entry were measured using state-of-the-art instrumentation to quantify various parameters. Air velocities near the face were found to be satisfactory to dilute contaminants from the face. A model for the axial velocity profile of the jet was suggested. Beyond 25m distance from the jet fan exit the jet tended to move away from the wall to the opposite wall. Carbon dioxide was used as a tracer gas to measure the effective ventilating air quantity near the face and re-circulation in various tests. The re-circulation involved in the system was found to be less than 40% in all the experiments. It was also found that the use of line curtains in combination with a jet a fan can eliminate any type of re-circulation.
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