3 July 1998

Heres a low cost cleaner with no moving parts

Producing clean grain is

becoming ever more important.

Now a novel machine offers

the prospects of clean grain

from a low cost, compact

machine with no moving

parts.We take a closer look

A SIMPLE cascade grain cleaner from Alvan Blanch attracted a great deal of attention at last years Grain event.

A unit is now under test on a Warwickshire farm, to both evaluate its performance and to establish the combination of sieve sizes needed to clean UK produced cereals.

Innovative in design, the cleaner, which measures 1.8m high x 1.2m wide x 60cm deep (6ft x 4ft x 2ft), has a theoretical throughput of 25t/hour and has no moving parts.

Grain is fed into the top of the cleaner where a cyclone or aspirator removes dust and light material. The rest of the grain free falls between a series of overlapping interchangeable curved-tine sieves angled at 45í. Separation comes from a combination of the size, weight and density of the material which, when it hits the grid fingers, sets up a trembling action.

In the upper section of the cleaner, this vibration directs stones and heavier material down the middle channel and sieves out the grain which is diverted into channels in the lower section of the tower, running either side of the centre compartment, where there are further sets of sieves with the same layout.

As the interval between the fingers on the sets of sieves is reduced going down the cleaner, so the grain is progressively cleaned as it falls from the top to the bottom of the tower, where there are separate outlets for contaminants and clean grain.

According to Alvan Blanch, the unit is a pre-cleaner, falling between a simple aspiration system and a fully-fledged grader and it is intended for the small acreage cereal grower who just wants an acceptable sample at not much cost.

And that is exactly what Andrew Pick wants at Bury Court Farms, Shotteswell, Warks, where he is evaluating the cascade cleaner.

The farms 202.4ha (500 acres) are down to 99ha (245 acres) of wheat, and 34.4ha (85 acres) each of oats, peas and linseed, with three quarters of the wheat and the peas fed through a 180-sow pig enterprise taking progeny to bacon.

"We want to get the drying system as automated as possible, within the restrictions of budget and building size, and the cleaners dimensions, simplicity and cost make it appear ideal," he explains.

Once installed, the cleaner will work in conjunction with a second-hand 100t capacity Wilder batch drier, which is to act as a back up for the farms on-floor system. Between now and harvest it will be a case of continually circulating some cereals and peas through it to find the correct sizes and combinations for various crop types.

"It will be a case of trial and error, but there is no gain without pain," observes Mr Pick.

Alvan Blanch has already made one modification to the sieves. In trials on the companys farm at Chelworth, Glos, it was found that stones could stick between the sieve fingers, wedging them open, which, as well as allowing large particles to pass through, stopped the vibrating action. To cure the problem, the tine ends are now supported by a full length strip of flexible, spongy material.

Mr Pick cannot see where the cleaner can go wrong, but all of his observations will be reported back to Alvan Blanch which aims to launch the cleaner this Smithfield with a price of about £4500. &#42

No moving parts and a compact design make for a low cost approach to grain cleaning- just what Warks farmer Andrew Pick is after. Right: As grain cascades through the cleaner numerous sets of fingers remove contaminants leaving clean grain at the bottom. The compact design suits confined spaces.

Finger spacing varies through the cleaner so that all contaminants are removed. An Alvan Blanch modification sees foam strip supporting the leading edge of each sieve set so stones do not wedge fingers open.