1. Felipe Calizaya Miles Stephens 2010 UTILIZATION OF BOOSTER FANS IN UNDERGROUND COAL MINES Stewart Gillies Univ. of Utah, Salt Lake City, UT Missouri Univ. of S&T, Rolla, MO

2.  Introduction  Project Objectives  Utilization of Booster Fans  U of U Coal Mine Model  M S&T Experimental Mine  Summary Outline

3. INTRODUCTION Booster Fan: 1)An underground fan installed in the main air stream to handle the quantity of air circulated through a section 2)Installed in a permanent bulkhead and equipped with a set of airlock doors and fan monitors 3)A properly sized and sited booster fan can be used to create safer work conditions and allow the extraction of minerals from great depths

4. Introduction Section A Section B Booster Fan Surface Fan Regulator Stopping Intake  A booster fan decreases main fan pressure & leakage  It requires a fan monitoring system

5. Introduction Transducer List M 1 Smoke M 2 CO M 3 Air velocity M 4 Diff. pressure M 5 Vibration M 6 Temperature

6. Project Objectives  Investigate the conditions under which booster fans can be safely used in U/G coal mines  Monitor the performance of booster fans in a laboratory model and an experimental mine  Develop a booster fan selection method  Educate/Train M.S. & Ph.D. students in advanced mine ventilation

7. Utilization of Booster Fans In the U.S., booster fans may be used in metal and non-metal underground mines They are not allowed in U/G coal mines, except in anthracite mines (CFR 75.310) Currently, booster fans are used in a number of coal mines in Australia, United Kingdom, Poland, India, others

8.  In western U.S. mines, coal is extracted from seams covered with more than 1000 m of overburden, with increased gas and heat flow rates Ventilation Problems in Coal Mines  In most cases, high pressure main fans are used to supply the required quantities of air to the face  Booster fans can be used to assist main fans in overcoming these adverse conditions High pressure  High air leakage

9. Planning Example 100 K 120 Kcfm 80 K Main Fan Heading GOB 83 K Case 1: Determine the fan size (Single- Fan System) P = 10 in.w.g Q = 699 kcfm

10. Planning Example 100 K 120 Kcfm 80 K Main Fan Heading GOB 83 K P = 7.2 in.w.g Q = 663 kcfm Booster Fan Case 2: Determine the best combination of fan pressures Main Fan P = 2.2 in.w.g Q = 576 kcfm Booster Fan

11. Solutions to Sample Problem 1. Single Fan System Main Fan H, in.w.gQ, kcfmPower, HP 10.0698.81101.2 2. Two Fan System Main Fan7.2662.7751.9 Booster Fan2.2576.1199.7 Total Power: 951.6 HP Total Power: 1101.2 HP Net Power Saving: 150 HP

12. The University of Utah’s Coal Mine Model Model used to study leakage through “stoppings”

13. U of U Coal Mine Model  This is a 14.6-cm diameter ductwork configured in a common U shaped ventilation system  The intake and return drifts are joined by five cross-cuts (four stoppings and a face)  The system is powered by a 3 kW centrifugal fan equipped with a variable frequency drive

14. The U of Utah’s Coal Mine Model Perforated gate valves used to represent stoppings

15. A Leakage Flow Test Objective: to study leakage flow through stoppings in a laboratory model A test is conducted by installing a set of “stoppings” in the model & running the fan Air pressure measurements (Hs & Hv) are conducted. Then, these are use to calculate leakage flow quantities

16. Test Results Total Percent Leakage = 42 %

17. Future Work This model will be upgraded to include a booster fan, a gas injection system, and a set of ventilation monitors. Carbon dioxide will be used to simulate the gas generated at the face Objective: to determine the conditions under which flow recirculation can be avoided

18. Booster Fan (3 kW)Main Fan (5kW) Return Inlet 1.2 m Regulator ? Gas Source ΔHΔH Ventilation Monitors CO 2 The U of Utah’s Booster Fan Model Simulated Mine Gob

19. The Missouri S&T Experimental Mine The Missouri S&T Experimental Mine is a limestone mine, located outside Rolla, MO The mine is accessed by two adits and has three raises to surface It is ventilated by a 30 kW Joy axial fan (Fan duty: Q = 23.6 m 3 /s @ Ps = 1,000 Pa)

20. The Missouri S&T Experimental Mine Map D D

21. Initial Plans: The Missouri S&T Experimental Mine  Upgrade the main fan system  Install two booster fans in bulkheads  Install an electronic monitoring system (To monitor:  press, quantity, vibration, bearing T)  Collect data to determine optimal placement of booster fans

22. Summary  The U of Utah and the Missouri University are investigating the conditions under which booster fans can be used in U.S. U/G coal mines Ventilation surveys in two non-U.S. coal mines where B-Fans are used regularly  The project includes: Ventilation surveys in two deep and/or extensive U.S. coal mines

23. Questions? Booster Fans at Peabody Energy’s North Goonyella Coal Mine, Australia

24. Booster Fans at Peabody Energy’s North Goonyella Coal Mine, Australia Main Fan Duty: Twin centrifugal fans installed in the main return Each fan powered by a single 600 kW motor Central bypass to maintain ventilation when fan is off Q = 600,000 cfm @4.2 in.w.g. Booster Fans’ Duty:Speed: 472 rpm Q = 465,000 cfm @ 3.2 in.w.g.

25. Booster Fans at Peabody Energy’s North Goonyella Coal Mine, Australia

26. Summary  This project also includes: Monitor the performance of booster fans in a laboratory model and an experimental mine The development of an efficient booster fan selection program Training of six graduate students in advanced mine ventilation

27. Questions?