Pretoria-based pumps supplier and services company, Mechanical Rotating Solutions (MRS), delivered six flameproof mobile pump sets to a colliery in Mpumalanga in May.

MRS MD Franscois Steenkamp says the company chose Tsurumi 100 KTX flameproof submersible dewatering pumps as the most suitable for the specific underground dewatering application. MRS then manufactured mobile trolley units, incorporating flameproof panels, to complete the individual mobile pump sets.

MRS has recently taken a leading role in the supply, refurbishment and installation of flameproof products, having earlier this year commissioned an underground double

configuration flameproof pump set to a Mpumalanga colliery for the purpose of dewatering its shortwall coal mining operations. “The flameproof pump set is used to dewater unmined areas at a rate of 60 m3/h, or 60 000 𝓵/h,” says Steenkamp.

The Tsurumi KTX series is an explosionproof model of the general KTZ series of dewatering pumps, with Steenkamp noting that the pump is suitable for operations where an explosive atmosphere occasionally occurs.

He adds that KTZ pumps are designed to withstand the most demanding conditions, including those in the highly-abrasive waters in coal mining – especially during dewatering processes. Versatility is increased as each pump model has the capability of easily converting between high head and high- volume performance with an easy change of the impeller and wear plate.

The commissioned pump sets are constructed in such a way as to enclose the parts that could ignite the material being transported or found in the surrounding area. “Every KTX pump is equipped with a circle thermal protector (CTP), integrated in the motor housing; the CTP directly cuts the motor circuit if excessive heat builds up or an overcurrent caused by an electrical or mechanical failure occurs.”

Mounting the pumps on a trolley gives the client extra mobility, as they are able to move each individual pump set as the underground water level rises or the mining operation moves to a different location. “What gives our clients further peace of mind is that with this unit, replacement parts and spares, conforming with flameproof specifications, are readily available and can be delivered and installed within a short turnaround time,” says Steenkamp.

Often mined areas in a coal mine form a zone of broken rock rubble and the spontaneous heating of coal fines in these areas is not easily detected. MRS has, for over a decade, serviced the coal sector with solutions addressing the threats that fires pose to the coal sector.

During dewatering of a mine, electric submersible pumps are sometimes used, but a key consideration is that electric pumps are a potential spark hazard, which could, in turn, ignite explosive vapours often found in coal mines, explains Steenkamp.

Mine damps are often released during drilling, blasting and other mine operations. The confined space means that the gases are unable to disperse, which can lead to explosions.

He concludes that, having pumps not fit for purpose, could lead to disaster, as a small spark could ignite any gases present in the area. MRS supplies and installs pumps specifically designed and customised for the areas they operate in, adhering to various regulations as prescribed by the mining industry.