Archive Article: 1997/11/08

8 November 1997

SAVINGS on water and energy underpinned new developments at this years irrigation event. First, theres the claim of more robustness and reliability with new Monsoon hosereeler. It combines UK and German engineering from Oakleys irrigation and Beinlich respectively.

Beinlichs trump card, reckons Oakleys general manager Dick Hewitt, is its by-pass turbine, suitable for slurry and dirty water as well as clean water applications. The turbine and gearbox use water flow to regulate reel-in speed and application rates. Connection and delivery pipes of the same diameter are said to improve efficiency.

Variable speeds in the range 10 to160m/hr are controlled by electronic switchgear, and all the key components are grouped together on the front of the machine.

The Monsoon complements the Bauer range, which Oakleys distributes in the west of the country, claims Mr Hewitt.

"The three-model range takes over where Bauer leaves off on big machines, with four diameters of hose up to 140mm, and hose lengths up to 640m for a 125mm diameter hose."

Single or twin axles can be specified except on the largest model, where twin axles are standard. An axle height of 500mm gives good clearance over crops or rough ground.

Standard equipment includes a two-way water inlet, PTO wind-in and a hydraulic gun cart lift. Operational safety is provided by high and low pressure plus manual flow shut-offs and a reel brake.

Suitable for use with any standard raingun or increasingly popular booms, prices for the Monsoon start from £16,384. Oakleys is also marketing Beinlich booms, in construction widths from 28 to 72m.

As for energy, savings of 5 to 25% on pump electricity bills are offered with Unicos inverter drive and electronic control system, according to the Farm Energy Centre (FEC).

Tests were carried out over four months this season on an irrigation system with two 55kW pumps, one fitted with an inverter drive to give variable pump speed, the other conventionally fixed speed. The electronic control system used either the variable speed pump alone or both pumps together to give the required water flow without the need for mechanical pressure regulators which, says the FEC, sap energy.

According to FEC engineer Andrew Kneeshaws calculations, this system uses 8% less electricity than one with two fixed speed pumps and mechanical pressure control. In some installations, savings up to 25% are possible, he says.

"Inverter drives can almost eliminate the sudden demand for high power thats normally needed when pumps are first switched on. So, for new installations, a smaller, and therefore cheaper, electricity supply can be specified," says Mr Kneeshaw. Savings here should go a long way to offset the estimated £8,000 to £12,000 the system typically adds to installation costs for a 100hp pump.

"Retrofits to established operations will also help to get the most out of the electricity supply without overloading the transformer," he adds.

Additional features include a remote control mechanism so pumps can be turned on and off from the field, and an automatic cut out in the event of a pipe burst or blockage.

The Unico system tested by FEC is distributed by Gwent-based Powerflow Services.

Solutech, one of the largest suppliers of agricultural sensors in the UK, is introducing another two natty devices to its range of irrigation scheduling aids.

The Watermatic soil moisture sensors are a derivation of the tensiometer principle. However, they are completely automatic, each pre-set to a crop specific soil moisture tension. So adjustment is not needed during set up or operation.

The ceramic sensor blocks are buried at rooting depth and connected to the controller. By setting the Watermatic to trigger irrigation when it senses soil moisture tension dropping below the threshold for the crop, it can by-pass the timer, reducing the risk of overwatering.

However, points out Solutechs Justin Smith, it wont take full control unless you want it to. Instead it can be set to activate an alarm at the critical moment.

The Aquaprobe is a second variation on the tensiometer theme, looking more like the conventional article but in miniature. Its advantages over standard tensiometers are that it records tensions up to 10 bar, compared to just 1 bar, and that its a sealed unit with no need for refilling.

Its also cheap, says Mr Smith, costing from £20. Connecting it to a transducer for data-logging purposes is also relatively cheap, he claims.

Most appropriate for glasshouse, turf and horticultural applications, Aquaprobes will be available in 1998.

For a splash of new product lines, news and irrigation advice, Tia Rund dips into the

Water for Farming 97 event at Peterborough.

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