Post on 16-May-2015
description
Improving Longwall Hydraulics –Kestrel Coal Case StudyTristan Lovell
22 October 2012
Summary
This presentation will cover:
• Kestrel Location
• Longwall Equipment
• A brief history of Kestrels Longwall Hydraulics
• Improvements
• Lessons Learnt
Kestrel Mine in production
since 2002
Kestrel Mine Extension
production forecast in 2013
Operations are adjacent to
agricultural land use
22 October 2012
Longwall Equipment
Equipment Kestrel Mine
Shearer Cat EL3000
Roof supports 146 x 860t + PM4
AFC 855kw CST P drive M-gate
855kw CST KP drive T-gate
Pump station SES (900 L/min) + Kamat (900 L/min)
Crusher 250 kw drive unit
BSL 400 kw drive unit
Monorail Macquarie system
Nameplate capacity 2500 tonnes per hour
Kestrels Longwall Hydraulics – A brief history
• The Longwall Shield hydraulic arrangement at Kestrel Mine consisted of a
single pump station arrangement being fed by an underground mix of oil
and water to create an emulsion.
• The system used a mechanical mix system and back up venturi style
mixing unit to siphon oil and water together
• The system also utilised an oil pod arrangement that required replenishing
every second or third day.
• This system of supply was logistically inefficient.
Tanker fills
bulk surface
tank with oil
Supply team
fill oil pod on
surface and
transport
underground
Empty pod
swapped with
full pod and
transported to
surface
Kestrels Longwall Hydraulics – A brief history
• The water supply used for Kestrels emulsion mix began as filtered raw
water:
• This system performed adequately for a number of years….
Surface filtration
system
Underground sand
filter pod
Mixed with
oil
Offsite
supply
22 October 2012
Kestrels Longwall Hydraulics – A brief history
• During the 2008 flood event in the Emerald region sediment build-up in
the local water supply increased dramatically.
• The raw water filtration system was inadequate to keep up.
Valve damage from contamination.Raw water filters often overloaded & by passed
Improving the system
• During this flood event – the hydraulic performance of the longwall shields
became diminished and a spotlight on the system was shone.
• An assessment of the system was undertaken and a number of key areas
for improvement were identified:
• Water quality – absolute and minimal variability
• Fluid control – a higher level of consistent ratio Water to oil mix was
required
• Environmental Quality – the impact of the hydraulic component of
the mixed product needed be minimised.
22 October 2012
Improved Water quality
After the flood event of 2008, a dedicated water line run from the onsite
water treatment plant was installed into the underground Longwall panel.
By taking water directly from the water treatment plant, variability in water
quality could be eliminated and high quality clean water could be used to
mix emulsion.
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Usag
e R
ate
(L
/m)
Months
Emulsion Usage Rate
FLOOD EVENT INTRODUCTION OF
TREATED WATER
CLEANING SYSTEM
22 October 2012
Improved Fluid Control
At the beginning of 2010, a Q-mix surface mixing plant was installed.
With the underground mechanical mix on demand system, concentration would vary by up to
75% of target concentration.
The Q-mix PLC controlled system reliably maintains +/- 0.1% accuracy, continuously monitors
the fluids other essential properties, and ensures that the longwall is delivered the highest
quality fluid at all times.
Mixing plant control module Kestrel Citect diagram
22 October 2012
Improvement: Synthetic fluid
Converted to new technology synthetic fluid, Quintolubric with:
• Increased corrosion protection
• Higher lubricity
• Cleaner operation
• Lower operating concentration (2%)
• Higher safety
• Lower environmental impact
Improved Environmental Footprint
No mineral oil from hydraulic leaks
Biodegradable 97% in 28 days
Reduced Chemical Oxygen demand (COD) by 75%
Reduced risk of impact on ground waters
22 October 2012
Improved Cleanliness 1. Reduce filter usage
2. Increase life of HP pumps and reduce seal gland replacement
3. Expand solenoid valve life
22 October 2012
Improved filtration
Emulsion Fluid
Filter
Particles
Synthetic fluid
Oil Particles
Increased Contamination capacity & lifetime• Less oily residues
• No water soap residues
• No antifoam residues
• Higher efficiency through thicker caking
Profile filter use over time
0
10
20
30
40
50
60
70
80
Nu
mb
er
of
Filte
rs U
sed
Week
Almost complete elimination of
profile filter usage over 4 years
22 October 2012
Improved Pump station performance
Decrease Contamination
• No mineral oil to soften seals
• No particles agglomeration to wear plunger
• No aeration to expand and destroy plunger surface
• Improved pump efficiency through less foaming
Lower Maintenance cost
• Seals change out time decrease by 2 times
• Extend ceramic plunger life
Productivity Improvement
• To replace damage parts for the high pressure pumps
22 October 2012
Improved solenoid performance
Decrease Contamination
• No fatty acid soaps to block the solenoid valves
• No antifoam blocking the solenoids
Lower Maintenance cost
• Solenoid change out decrease significantly
Productivity Improvement
• To replace solenoids
Solenoid Usage Over Time
0
20
40
60
80
100
120
140
160
Nu
mb
er
of
So
len
oid
s U
sed
Week
Downward trend of solenoid
usage over 4 years
Lessons Learnt
• The longwall shield hydraulic system is key to the assets health
• A set and forget approach to shield fluid systems will eventually lead to significant loss in productivity and an increase in material cost
• Active measurement and management of the use of hydraulic fluid will ensure an operation understands its systems health
• Increased performance, environmental improvement and cost reduction do live happily together – efficient solutions can and will yield all three
• An active interest in the technology advances available will ensure even aging assets can keep up with the latest standards and perform well.