February 2004
Colliery Dust Control (CDC) of Springs, South Africa’s leading suppliers of
dust suppression equipment and systems for continuous miners, has steadily
improved the quality of its products and services over the years, resulting
in substantial cost savings for its customers in addition to greater dust
suppression efficiency.
“Underground collieries have significantly reduced both capital and running
costs by upgrading their equipment and systems to the more advanced and
efficient models we and our associates are constantly in the process of
developing,” commented Doug Hutson, CDC’s managing director.
“In addition, customers who have taken repair & maintenance contracts with
us have achieved further cost savings as a result.”
Hutson emphasised that the cost savings achieved are not limited only to the
dust suppression equipment costs, but also impact positively on the overall
efficiency and productivity of the continuous miners. “Based on feedback
from customers, the cost savings achieved on the continuous miners as a
whole as a result of the improved productivity and efficiency of our systems
and services has been significant over the past five years,” he said.
“The cost savings and productivity gains are due to a combination of factors
that include improved equipment reliability, more efficient application of
the equipment, better maintenance, less repairs, fewer replacements of parts
and, last but not least, reduced downtime as a result of all this.”
He listed three main headings under which such gains and savings have been
achieved: equipment improvements/upgrades, better positioning and
integration of the equipment on the continuous miners and improved
maintenance – including maintenance and repairs executed by CDC under
contract maintenance deals.
Upgraded equipment:
“Where CDC can take full credit is for improvements in the
products we supply,” Hutson remarked.
“Some of this has been achieved by 100 per cent inspection of all components
that are purchased from sub-contractors to ensure that they meet our minimum
specifications. We have revamped our pump shop three times and on each
occasion have improved the equipment, the working conditions and the
training of our pump repairmen. As a result pumps go out fully tested with
QA checks during the rebuild and, together with the contract maintenance,
pump life is measured not in months now but in years.”
The fan manufacturing techniques have also been improved, inspection
procedures have been uprated and fan failures are now a thing of the past,
he added. “Impellers are now hard chromed to increase life and because this
allows us to use mild steel blades, welding techniques are easier to apply
and reliability has improved, getting a double whammy out of the exercise.
“But perhaps some of the biggest improvements have been in the fan motor.
This has gone through ongoing and extensive upgrading over the past eight
years. Improvements have been made as and when necessary due to experience
in the field and also as better manufacturing and design techniques have
become available.”
Hutson said it has been the policy of both CDC and Transvaal Electric, the
Johannesburg-based designers and manufacturers of the fan motors, to upgrade
the manufacturing and design parameters of the motors as soon as new
technology becomes available – not just when it proves necessary. “In this
way, the reliability of the motor has been continuously improved and in
2003, for example, we have not had a single warranty repair.”
Most of the development work on the motor has centred on the bearing and
seal arrangements, as well as the rotor bars and windings.
Better positioning and integration:
High priority has been given to
improved installation and maintenance and to this end the company appointed
customer support engineers who spent time at the collieries advising the
mine engineers and other technical personnel on how best to mount CDC’s
equipment on the continuous miners to achieve maximum dust suppression
efficiency, as well as on how to maintain the equipment.
“Today by and large the mines are much more alive to the benefits of
preventative maintenance than they used to be. In the early stages, before
this level of awareness had been reached, we used to do a roaring trade in
repairs, replacements and service, but this wasn’t good business for either
the customer or for CDC in the long run, so we set about trying to improve
the situation,” Hutson explained.
As far as improved positioning of equipment is concerned, he said the
biggest savings have been made with respect to the scrubbers. “Working
hand-in-glove with the mines we now mount the scrubber in a better position,
not only from the dust control aspect by moving the intake closer to the
picks, but also to a position where it is less likely to be damaged during
the movement of the continuous miner.”
Improved maintenance:
While assisting mine personnel to improve the operational
efficiency and maintenance of the equipment, the company also set about
selling the concept of contract maintenance on the basis that while the
collieries know best how to mine coal, CDC is best qualified to maintain the
dust suppression equipment directly.
Said Hutson: “Initial reactions were understandable, as even at the low cost
rate that we charged for a maintenance shift, to the mine it still seemed
relatively expensive compared with employing their own people for the
purpose
.
“However, they were eventually convinced over time
that it is cheaper to use a CDC contract technician when all the losses and
costs due to inadequate maintenance are taken into account. For example, the
first mine that we did contract maintenance for were returning pumps to us
for repair almost on a monthly basis before they came on board. Once the
contract maintenance had gone into operation, we did not get a pump back
from them for over 18 months.
“We have seen pump repairs drop by almost 50 per cent and a similar decline
in repairs on scrubbers has occurred. This is partly due to better care by
the mines and to our contract maintenance and also to better positioning of
the equipment on the machine.
Conclusion:
“As a result of these ongoing efforts
to improve reliability and reduce downtime, CDC’s turnover in spares and
maintenance has actually shown a steady decline over the last five years.
However, this has been offset by a reduction in costs due to reduced
warranty claims and staff.
“Our customer support is good and keeps equipment in service longer to
prevent downtime. One of our greatest strengths is that we are a
service-orientated company. Our turnover depends as much on good service as
on offering a top quality and competitively priced product,” Hutson
concluded.
CDC was the first dust suppression
equipment supplier to consistently meet the regulation minimum dust count
requirement of under 5 mg/cu m as laid down in the Mines Health & Safety
Act. This is achieved in the workplace through the application of CDC’s
unique three-in-one integrated dust suppression system comprising the CDC
wet-fan scrubber box, water powered air movers and spray fans operating in
complementary fashion, combined with good management, good ventilation
practice and good mining practice by the collieries concerned.
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