SPUD WASHING MACHINES SUPPLY A DIRTY BUSINESS
Demand that potatoes
should now be washed before
delivery to the processor has
created an opportunity for
contractors to offer a new
service to local growers.
Mike Williams reports
DIRTY potatoes are unpopular with big processing companies producing crisps and other products. Dirt washed off at the factory becomes an industrial waste with expensive disposal costs, and the proportion of rejects is often much higher when dirt masks damaged or green potatoes which should have been graded out on the farm.
Walkers was the first company to insist that potatoes must be washed before delivery is made to its factory. That was nearly four years ago and since then some of the other big processors have followed this example, creating a demand for washing equipment big enough to cope with the throughputs demanded by merchants and big acreage growers.
Leading manufacturers include Peal Engineering which makes the Prowash brush type washers – a range which now includes a new version with a destoner unit. The alternative is the barrel washer made by Tickhill Engineering which supplies the Haith Supawash range. Both types can be supplied to operate as a fixed installation, but a more popular idea is to mount them on wheels for moving to different locations.
Throughputs claimed by the manufacturers start at about 20tph, but the top model in the Supawash range can handle up to 60tph, it is claimed.
Most of the potato washer customers are growers, according to Peals sales manager, Ken Hollingsworth, and mobile versions towed behind a tractor are popular, he says. These can be operated by groups of growers who share the capital costs ranging from just over £20,000 to £75,000 plus for a full spec machine on a truck type trailer.
Some machines have also been sold to contractors, and this arrangement can work well because a lot of growers are interested in the idea of washing their crop, explains Mr Hollingsworth.
One contractor who takes potato washing seriously is Ken McNeil of Pocklington, York. He bought his first Haith Supawash mobile barrel washer just over two years ago and added a second Haith machine a few months later. Although he lives in Yorkshire, Mr McNeil operates both machines in Shropshire, working mainly for growers.
"Apart from meeting processors demands for clean potatoes, washing the crop also has benefits for growers," he says. "The biggest advantage is that it makes grading for mechanical and other defects easier when the potatoes are clean, and this allows the grower to opt for tighter grading standards when necessary."
Another advantage with washed potatoes is that large amounts of soil do not have to be transported, which can add significantly to haulage costs.
"The performance of the two barrel washers has been excellent, and they can easily exceed their 20 tph rated throughput, but maintaining a flow of work for the two machines is not always easy," says Mr McNeil.
He points out that some merchants have installed their own washing equipment and insist that growers use these machines, even though he can undercut their £3 per tonne charge.
There is also concern about the effluent problem washed potatoes produce. "Large volumes of dirty water are an inevitable bi-product, and you have to be careful to keep it away from rivers and streams. I have not had a problem, but I believe the authorities are now keeping a watch on this sort of activity."
Efficient effluent disposal was one of the priorities when Yorkshire farmer, Jimmy Stockdale installed a Peal Prowash on his Starr Carr Farm, Seamer, Scarborough. Mr Stockdale, who is a potato merchant as well as farming about 730 ha (1800 acres), installed the washer recently to make grading easier and more efficient, and he is pleased with the results.
"You cant expect the girls on the grading line to do a good job if the potatoes are covered in dirt," he says. "We have only been using the washer for a few weeks, but it is certainly living up to expectations. We have quite a lot of spare capacity on the washer, and I am planning to offer a contract service to other growers in the area. I have mentioned it to one or two growers, and there appears to be some interest in the idea."
Mr Stockdales potato washer is installed with its own dedicated drainage system including an overflow tank to minimise the risk of pollution problems caused by dirty water. *
A Haith Supawash machine supplied on a road-going trailer.
The newest addition to the Peal Prowash range includes a destoner unit.