felipe calizaya michael g. nelson jessica wempen randy peterson 2011 utilization of booster fans in...
TRANSCRIPT
Felipe Calizaya
Michael G. Nelson
Jessica Wempen
Randy Peterson
2011
UTILIZATION OF BOOSTER FANS IN UNDERGROUND COAL MINES
University of Utah, Salt Lake City, UT
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
Daw Mill Colliery3
Daw Mill Colliery is the most significant coal mine in the UK producing 3 million tonnes per year
The mine is deep and extensive with a depth over 850 m and over 7.5 km of workings
A retreating longwall is used as the primary means of production
Longwall panels are developed with a single entry. Panels are 2,500 m long and 350 m wide
Isolation pillars from 90 to 180 m wide are left between each panel
Daw Mill Colliery Ventilation4
One intake shaft and one exhaust shaft
A surface drift used to transport coal provides 20 m3/s of intake air
Two exhausting centrifugal surface fans are installed on the surface. One fan is active and one fan is redundant
Both surface fans are capable of operating at 169 m3/s with a pressure of 2.8 kPa
Production headings are ventilated with at least 6.5 m3/s, this is driven by a 90 kW auxiliary fan operating at 3.5 kPa
Daw Mill Colliery Ventilation5
One booster fan site that consists of four 2 m axial booster fans with a combined capacity of 120 m3/s with a pressure of 3.5 kPa
b) Long -section View
a) Inlet Side SS
FF
a) Cross-section View
Inlet Outlet
Daw Mill Colliery Ventilation6
Booster fans are located in the return and the motors are enclosed in flame proof housing
Because of the risk of spontaneous combustion booster fans were installed in rock above the coal seam
Booster fans are sited inby the current neutral ventilation point so there is a small amount of air recirculation (less than 10%)
Booster fans are essential to provide adequate air volume and control heat. The fans increase the volume of air at the longwall face by 50%
Daw Mill Colliery Ventilation7
Ventilation challenges include:
Methane – 2 m3 of methane per ton of coal
Spontaneous combustion – can occur regularly during development and salvage operations
Daw Mill Colliery Ventilation8
Methane and carbon monoxide levels are measured throughout the mine
At the booster fans airflow, pressure, vibration, bearing temperature, methane, and carbon monoxide are constantly monitored
In addition to electronic monitoring, a tube bundle system is used to monitor air quality
Because of the high risk of spontaneous combustion a nitrogen system is used
Maltby Colliery9
Maltby Colliery produces 3 million tons per year ROM and 1 million tons per year clean coal
A retreating longwall is used as the primary means of production and is supported by four development sections
Longwall panels are developed with a single entry system
The mine is deep and extensive with a depth over 960 m and over 8 km of workings
DEPTH IN METRES.
BARNSLEY SEAM
SWALLOW WOOD SEAM
HAIGH MOOR SEAM
PARKGATE SEAM
THORNCLIFFE SEAM
812m
822m
960m
982m
No.1 SHAFT No.2 SHAFT No.3 SHAFT.1911-1972SEAM EXHAUSTEDAFTER 61 YEARS
WORK BEGAN 1970SEAM ABANDONED
1993.
SEAM PARTIALLYWORKED LATER
ABANDONED.
CURRENTWORKINGS
Maltby Colliery
Maltby Colliery Ventilation12
Two intake shafts and one exhaust shaft
Two 5.3 m centrifugal exhaust fans are installed on the surface. One fan is active and one fan is redundant
Both fans are capable of operating at 280m3/s with a pressure of 5.5 kPa.
Maltby Colliery Ventilation13
One 2.05 m axial booster fan operating at 140 m3/s with a pressure of 7.4 kPa
Section View
Airflow
Screen
Diffuser
Bulkhead
Drift Floor
Impeller
Motor
Maltby Colliery Ventilation14
Maltby Colliery Ventilation
Ventilation challenges include:
Heat – Virgin rock temperature is near 42⁰C and air picks up an additional 7 ⁰C across the booster fan
Humidity – High water usage for dust control and machine cooling
Methane – 25 m3 of methane produced per ton of coal
Frictional Ignition
15
Maltby Colliery Ventilation16
Booster fan is located in the return and the motor is enclosed in flame proof housing
Booster fans are essential to provide adequate air volume and control heat
Booster fan is sited inby the current neutral ventilation point so there is some air recirculation
Methane drainage system is used to control excess methane
Maltby Colliery Ventilation17
Booster fan installation includesfour airlock doors between the intake and the return. Three airlock doors are used in the fan bulk head
A manometer and a digital pressure gauge are used to measure pressure across the bulk head
The installation includes a water barrier to control fire that may occur at the fan
Maltby Colliery Ventilation18
Methane is monitored in the intake and in the return upstream and downstream from the fan
Carbon monoxide and smoke detectors are located downstream
A tube bundle system is also used to monitor the air quality
Maltby Colliery Ventilation
Intake
Return
Man Doors
Booster Fan
Airlock Doors
Bulkhead
To Tail Gate
Tube Bundle
MethaneCarbon Monoxide
Manometer
Smoke
Delta Press
Fan and Environmental Monitors
Kellingley Colliery20
Kellingley Colliery produces 2.3 million tons per year
A retreating longwall is used as the primary means of production and is supported by four development sections
Longwall panels are developed with a single entry system
The mine is deep and extensive with a depth over 800 m and over 9 km of workings
Kellingley Colliery Ventilation
21
One intake shaft and one exhaust shaft
Two 4.14 m centrifugal blowing fans are installed on the surface. One fan is active and one fan is redundant
Both fans are capable of operating at 290 m3/s with a pressure of 2.5 kPa.
Kellingley Colliery Ventilation
22
Three booster fan sites all located in the return
Single 1.6 m double inlet centrifugal fan operating at 290 m3/s and7 kPa
Four 1.2 m axial fans operating at 68 m3/s and 2.5 kPa, two installations one in the return and one in intake
Kellingley Colliery Ventilation
23
Diffuser
BulkheadCasing
InletDischarge
Centrifugal Booster Fan
25
Kellingley Colliery Ventilation
Intake
Return
Bulkhead
Airlock Doors
Booster Fan
Airlock Doors
Methane Carbon Monoxide
TemperatureDelta Press
Fan and Environmental Monitors
26
2 x 2 Booster Fans
Return
BulkheadAirlock Doors
Intake
Kellingley Colliery Ventilation
27
Ventilation challenges include:
Methane, Heat, and Dust
Booster fans are essential to provide adequate air volume and control heat
There is a small amount of air recirculation (less than 10%)
Turbulence around the multi-fan installation can be a problem
Significant Differences in Ventilation Practices Between the UK and the US28
Booster fan installations are common and are accepted as a safe and effective means of ventilating sections
Booster fans are often viewed as the only option for providing adequate ventilation underground
Booster fans are most commonly axial fans installed in clusters with up to four-two stage fans per site and all fans were installed in concrete bulk heads
Booster fans were selected based on each mines pressure and quantity requirements
Significant Differences in Ventilation Practices Between the UK and the US29
Two types of parameters were monitored at each fan: fan parameters and environmental parameters
Fan parameters included differential pressure, motor and bearing temperatures, and air velocity
Environmental parameters included methane, carbon monoxide, and smoke. Atmospheric monitoring systems were extensive and robust
Booster fans were most often located in the returns in series with the main fans
Motors and electrical components were located in the return but were contained in flame proof housing
Significant Differences in Ventilation Practices Between the UK and the US30
There was no electrical interlocking between the main fans and the booster fans at any of the mines
All of the coal mines were using single entry systems with barrier pillars between the longwall panels
No neutral entry for the conveyor belts were used. Belts were used in both intake and in return airways
Recirculation and series ventilation are not strictly prohibited. Most mines using booster fans were recirculation about 10% of the air
31
Booster fan model for Highland 9 Mine
North
East Mains
North Mains
West Mains
Unit 1: 9.4 cms
Legend
Main Fan
Unit 4: 9.4 cms
Unit 2: 9.4 cms
Unit 5: 9.4 cms
Unit 3: 9.4 cms
Mined Out Area
Mined Out Area
Highland Mine projected ventilation network using only a main fan
Summary of Results: Main fan duty: 200 m3/s at 2.24 kPa Total airpower: 440 kW
North
East Mains
North Mains
West Mains
Unit 1: 9.4 cms
Legend
Main Fan
Unit 4: 9.4 cms
Unit 2: 9.4 cms
Unit 5: 9.4 cms
Unit 3: 9.4 cms
Booster Fan
Mined Out Area
Mined Out Area
Highland Mine projected ventilation network using one booster fan
Summary of Results: Main fan duty: 180 m3/s at 1.37 kPa Booster fan duty: 150 m3/s at
0.57 kPaTotal airpower: 330 kW
North
East Mains
North Mains
West Mains
Unit 1: 9.4 cms
Legend
Main Fan
Unit 4: 9.4 cms
Unit 2: 9.4 cms
Unit 5: 9.4 cms
Unit 3: 9.4 cms
Booster Fan 1
Mined Out Area
Mined Out Area
Booster Fan 2
Highland Mine projected ventilation network using two booster fans
Summary of results: Main fan duty: 150 m3/s at 1 kPa Booster fan 1 95 m3/s at duty 0.5 kPaBooster fan 2 : 65 m3/s at duty 0.5 kPaTotal airpower: 230 kW