Local developer and supplier of integrated dust suppression systems for the improvement of working and safety conditions in underground collieries Colliery Dust Control (CDC), was approached by one of its customers about three years ago to see if it could solve an ongoing problem it was having with the methane monitoring heads on its continuous miners.

CDC established that many underground collieries using that particular brand of methane monitor were experiencing similar problems with the product. "These mines were replacing methane monitoring heads on a weekly basis and sometimes up to six times a month," comments CDC MD Doug Hutson.

"This was at a cost of R5 000 each and one mine was carrying stock of 70 methane heads valued at R350 000 in order to ensure continuity of supply and the least disruption to production," adds Hutson.

The customer in question was seeking development of a new product with the same level of reliability as the Aquaguard pressure and flow transducers supplied by CDC's specialist monitoring systems partner, Monitech Mining Monitoring Systems.

Monitech got to work to solve the problem and within a short time came up with a monitor incorporating all relevant monitoring functions, including methane monitoring, in a single unit. This is its eight-channel monitor, which, in addition to water pressure and flow and methane (two monitors), also monitors coolant pressure and flow (two monitors each).

"In contrast to the previous system used, the methane monitoring system incorporated in the eight-channel logger is reliable, as well as being very responsive and accurate," says Hutson.

The first unit was installed three years ago and since then, only two methane sensor heads have been replaced on that unit.

"A total of 23 units have now been installed over the 36-month period and an analysis of the running costs of the units for those that have been running for more than 12 months shows that costs are of the order of R1 000 per month. This compares with up to R40 000 per month for the units supplied by the previous supplier," comments Hutson.

"The project has been a success story for customers, CDC and Monitech, with enhanced safety and greatly reduced costs," he concludes.

CDC, of Springs, and Monitech, of Benoni, have a cooperation agreement to promote and sell Monitech monitoring equipment to the coal mining industry. This has worked to the benefit of both companies in winning new business.

CDC is a supplier of dust suppression systems for continuous miners in Southern Africa. It first entered this market in the 90's with its three-fold dust suppression system, comprising the CDC wet fan scrubber box, a spray fan system and water-powered air movers operating in complementary fashion to achieve high dust suppression efficiency.

During this time, according to CDC, there was a revolution in the dust suppression industry in underground coal mining. Dust levels were climbing, as the industry was expanding, new mining sections were being opened, and the number of continuous miners in operation was increasing, as were production rates.

CDC says that at the same time the Department of Minerals and Energy (DME) was putting pressure on the industry to bring dust levels down to acceptable limits. CDC had originally developed dry fan systems that had been used for many years, but were no longer keeping up with the increased dust levels.

By using well-established principles and applying modern technology as well as different systems to meet the challenge CDC developed the integrated dust suppression system.

“The application of this three-part system, when used in conjunction with the principles confirmed by tests undertaken by the Council for Scientific and Industrial Research’s (CSIR’s) methane and coal dust explosion test centre, brought dust levels down to below the required upper limit of 5 mg/cu m and close to 2 mg/cu m,” says CDC.

The integrated dust suppression system lead to an improved working environment, improved safety, reduced downtime, increased productivity and reduced maintenance costs.