The Shotcrete Problem for Dewatering
There is no doubt Shotcrete does a great job helping stabilise the internal walls of mineshafts.
But the Shotcrete fibres create headaches for dewatering teams. Wherever Shotcrete is being used in mining and construction, small, tough Shotcrete fibres inevitably flow into the water and end up in proximity to dewatering pumps and pumping stations.
If the pumps or pumping stations fail, it can be costly because of delays to mining / construction and increased maintenance & repair expenses.
A Three Pronged Solution
The Shotcrete fibre problem has been crying out to be solved. At PumpEng, our engineering team worked closely with Australian dewatering crews to come up with JetGuard®, a pump that was better at handling Shotcrete fibre and reduced the hassle of pump breakdowns.
To address the problem, we used three strategies.
One part of our design approach was to focus on prevention. We had a long hard look at how to prevent (or reduce the amount of) Shotcrete fibre getting into the pump in the first place.
Many of the problem Shotcrete fibres float on the surface of the water. So we designed a water curtain to act as a hydraulic barrier to the fibre. We coupled this with a suction system and self cleaning strainer to minimise Shotcrete entering the pump. These approaches help significantly reduce the amount of Shotcrete entering the dewatering pump.
So now we had less Shotcrete fibre getting in, but some fibre will inevitably get through the first layer of defence.
The second part of our design approach was to pre-process the fugitive fibre to help minimise internal damage over the pump’s life cycle. As fibres enter the pump, they encounter a directional cutting assembly that chops up the Shotcrete fibres. Shorter fibres are easier for the pump to handle and do less damage.
The third part of our design approach was to toughen the pump itself. Shotcrete fibre is designed to reinforce concret, and even the chopped up smaller fibres are very strong and can wear down plastic components. Time to toughen up princess! Our design removed all plastic/polyurethane internal components that were more easily damaged by fibre. We created an all metal wet end construction that is far less open to tearing or lifting.
We called our new Australian designed pump JetGuard®. We’re really excited at the way it is being embraced in underground mining operations. We’ve got a joke around here that Jetguard is “The Pump That Eats Shotcrete Fibre For Breakfast”. Maybe that’s a bit much, but you get the general idea.