Water harvesting with submersibles

Departing from their original use in mining, submersible pumps are fast becoming a popular water harvesting mechanism in agriculture. Their ability to be installed in a range of settings makes them the perfect solution to bad weather and adverse environmental conditions.

Traditionally, engine drive and motor pumps are used to harvest river water into turkey nest dams or to supply irrigation systems. Usually located on the river bank, these pumps are often washed away or inundated during periods of heavy rain.

Installation of a Tsurumi high head submersible to harvest river water led to increased efficency and performance of the irrigation system on the Templeton’s sugar cane farm.

Moving a pump during bad weather is fraught with danger as the ground is likely to be slippery and falling into a river in a spate can be deadly.

One solution growing in popularity is the use of submersible pumps installed inside poly pipe sleeves that are secured to the river banks. Unaffected by changes in the water level, these pumps can be left to operate as required. Sugar cane farmers, the Templeton family, on Queensland’s Sunshine Coast, have changed their water harvesting system to a submersible pump. The new installation is a safer, flood proof solution for water harvesting that delivers 3,000 lpm at 850 Kpa.

The Templeton’s original two pump system had an 18.5kW end suction centrifugal pump mounted on a trolley beside the creek. This supplied water to a variable speed 75kW end suction pump positioned 18 metres above the creek water level, away from the highest known flood level. The combined pump system supplied water at a rate of 2,400 lpm, at 700KPA, to irrigate pasture, sugar cane and a valuable ginger crop on the Templeton’s farm.

In the event of heavy rain, a tractor was used to haul the old pump trolley up a 40 metre railway track away from the creek. Creek levels can rise fast, so this procedure had significant risks, especially when performed at night on a steep, wet, slippery bank.

The Pump House, a Nambour based local pump distributor, came up with an “out of the box” solution to the Templetons’ problem: a submersible dewatering pump.

Submersible pumps can be installed either in shallow wells or bores but they also lend themselves to being installed in shrouds or poly pipe sleeves. They can be mounted vertically or on a range of angles through to horizontal without affecting pump performance. In the Templeton’s case, a submersible pump meant that the pump could be left in the creek regardless of the weather, and they no longer had to risk their lives moving the old pump up the slippery creek bank in the wet.

Peter Chadband from The Pump House said “Dewatering pumps aren’t usually used for applications like this, but these big high head pumps are ideal for water harvesting from rivers or dams.”

The Templeton’s decided on an Aussie Tsurumi LH619 submersible dewatering pump and installed it inside a 630mm PN10 poly pipe sleeve. It now delivers water to the 75kW irrigation pump. The poly sleeve runs down the creek bank, secured by cables and chain anchors.

The 6” pump the Templeton’s decided on, a Tsurumi LH619, has a 19kW, three phase motor with DOL start. The pump produces a maximum 4,370 litres per minute flow and has a vertical head of 42 metres.

Although originally designed for mine dewatering, the Tsurumi LH series is equally at home in agricultural water harvesting applications. The centre mounted discharge means discharge pipes or hoses are balanced.

“We’ve seen the 75kW pump deliver more flow while drawing 10 per cent less current due to the increased efficiency gained by a positive suction pressure at the pump inlet. It’s a great outcome using less labour, and less energy with increased performance and improved safety for the client,” said Mr Chadband.

The Tsurumi submersible pump is totally different in design and concept to normal submersible water harvesters or line shaft pumps. The closed style impellers are manufactured from high chrome iron and are durable and corrosion resistant.

Further information on Tsurumi cost effective water harvesting pumps is available from Australian Pump Industries or authorised distributors throughout Australia.