16 February 1996

Grain: The drying game

The RASEs Grain 96 exhibition provided the ideal shop-window for growers looking to upgrade grain storage, drying and handling facilities. Peter Hill reviews some of the new developments on show

MC and diesel Farm Fans driers

With farm businesses continuing to expand through land acquisition and management contracts, there is a steady demand for portable crop drying equipment able to service two or more sets of storage buildings.

A newcomer to Britain is US manufacturer Mathews Company. Its horizontal portable (or static) continuous flow driers are being imported by Amtex of Leominster, Herefords. Grain entering the top of the drier fills a cavity between the outer screen and the inner screen to create a plenum chamber which is divided to provide drying and cooling sections.

Stephen Griffiths of Amtex explains that rather than simply bringing in the driers as is, they have been specified to suit UK users.

"The axial fans are replaced by quieter centrifugal fans from the larger units because noise is a more sensitive issue over here. These fan-types give better airflow for our denser crops," he points out. "Screens suitable for oilseed rape are fitted, made from stainless aluminium rather than punched galvanised steel for added corrosion resistance."

Two models are being offered initially, the 370C delivering 4.5t/hr, and the 570C rated at 7.5t/hr; outputs are increased in both cases with the cooling section removed. Prices are put at £19,950 and £24,450 respectively.

Diesel-fuelled versions of the Farm Fans horizontal batch driers use multi-nozzle heads rather than single or twin jets to give a cleaner burn, says the US firms Malcolm Cawston.

"Most diesel driers have either just one fuel nozzle, or two nozzles giving high and low flames," he explains. "We fit a more complex and expensive multi-jet system with five or seven small nozzles which produce a finer spray and give a cleaner burn. The system then automatically switches between two different pressures to give high and low flames to maintain a constant temperature."

Two models are being sold by UK importer Brice-Baker – the AB-180 rated at 4.6t/hr and the AB-350 at 8.3t/hr – figures which include typical filling and emptying times.

Ventacrop fan

Crop stores which need expanding but have marginal electricity supplies can opt for an engine-driven fan and save the cost of upgrading the power installation.

At £13,500 for a static model, £14,200 for the portable version, the price of the Ventacrop diesel-powered fan reflects its robust build, says Terry Hardcastle.

He bought the manufacturing rights to the Ventacrop from previous manufacturer Entecon earlier this year.

It can dry crops using air at ambient temperature or working in partnership with a modulating gas burner and the 1200mm (4ft) diameter fan is driven directly via a cushioning rubber coupling by a six-cylinder Ford diesel engine.

Screw conveyors

The System 2000 range of screw conveyors from Astwell Augers is aimed at heavy agricultural and industrial use with throughput of 10 to 110t/hr and casing diameters of 200mm, 250mm and 300mm.

Casings are hot dipped galvanised and connected by bolted flanges, drive is by vee-belts on steel pulleys, and hangar bearings at centres up to 3m (9ft 10in) reduce noise levels and eliminate auger flight wear.

Relatively slow running speeds of 290rpm and 430rpm keep power requirement in check.

Elevators and conveyors

Grain handling specialist Perry of Oakley is producing heavy duty chain and flight conveyors and bucket elevators, the former in 60, 80 and 100t/hr sizes, the latter 80 and 100t/hr capacities.

Overall dimensions and operating speeds are the same for all models; only the flight or bucket spacing is varied (together with motor size) to achieve different through puts.

The company is also producing round tube ducting to complement its established square ducting products. Items include ducts, fixed and swivel elbows, cut-off valves, Y-pieces, reducers, and two- and three-way valves.

Gas burners

A new modulating gas burner from Welvent has a more compact touch-membrane type control box incorporating the latest quick-dry microprocessor programme developed at the Farm Energy Centre.

The system compares the relative humidity in the main air duct of a bulk store with the moisture of the wettest layer of the crop to determine the amount of heat required.

More heat is used in the early stages, the extra running cost during this period being offset by a shorter overall operating time.

Several models are on offer with heat outputs from 43kW to 300kW (150,000 to 1m Btu). Prices start at £2190; the WSQ250 for a typical 30hp fan costs £2490.

The MHC3 gas burner control system, produced by Robydome Electronics to an Octagon Products design, can give priority to either humidity when drying grain and similar crops, or temperature when drying onions.

The compact push-button unit provides a selectable display of sensor readings.

Rest assured, its in there somewhere…the Ventacrop fan is diesel- as opposed to electric-powered. Fan prices range from £13,500 to £14,200.

Amtex of Leominster, Herefords, is customising these US-built portable driers to suit UKfarm conditions.

Niche gas-fired burners incorporate their own fans for air intake, hence reducing the derating effect on the main drying fan.

The Alvan Blanch "S"series continuous flow driers are now supplied more fully pre-wired, plumbed and erected. This enables same-day installation of the 8.25 to 22t/hour models.