Past Times: New ice plant ready for production
From The Shetland Times, Friday 9th June, 1961
This week-end Messrs J. & M. Shearer Ltd., of Lerwick, hope to be in a position to meet orders for the highly successful new flake ice. A plant to produce twelve tons of this ice has now been erected at Garthspool, and tests during the week have proved very satisfactory.
The Scottish Association of Cold Storage and Ice Trades, in their annual report, have stated that there is an increasing demand for flake ice, and it is suggested that this type might eventually completely supersede crushed ice for fishing purposes.
The plant installed by Shearers is the latest Hallmark ice plant. It is, in fact, the very first 12-ton plant to be installed in Britain, although the firm (Messrs J. & E. Hall, Ltd., of Dartford, Kent) are now manufacturing a 20-ton plant for installation in English ice factories.
An excellent job has been made of the installation in Shearer’s premises next to the present crushed ice plant. The building was just high enough to take the flake ice maker (which is actually housed in the old sail loft), poised over a 14 1/2-ton storage tank, which has a controlled output to the ground floor lorry-loading ramp. The workmen had quite a job getting the heavy plant manoeuvred into position in relatively cramped space, but the finished job is a very neat one. Messrs Hall’s own men did the installation, using Messrs Shearer’s own staff for labour. Messrs Wm. Baird & Sons supplied the steel erection.
For fishing purposes, flake ice is claimed to offer definite advantages. It requires no crushing and therefore reduces handling; it is light in weight so that it does not damage the fish; it does not pack whilst it remains super-cooled and dry.
The refrigerant occupies the annular space between the double walls of a vertical freezing drum, and cools the inner surface. A smooth and uniform flow of water is maintained from a water header at the top, on to the chromium-plated freezing surface, where it forms a sheet of ice.
The only moving part of the flake ice-maker is the rotor arm carrying the blades which remove the ice. Just before the blades crack and dislodge the ice, the water flow stops, and the ice becomes super-cooled and dry, so that when dislodged by the rotor blades it falls freely from the drum into the collecting and storage bins.
The water that has not been converted into ice is aerated in the water system before it is returned to the water header, and thence back to the freezing surface. Flakes produced by the process are of irregular shape and average an inch square, and from one-sixteenth to one-eight inch thick.
The plant should produce at least twelve tons daily – in actual practice it may well do better than that. Already Shearer’s crushed ice plant turns out 24 tons daily. So, with two plant, plus the reserve which is kept, the firm could supply around forty tons a day for a week and still not run out. That should be sufficient to meet all demands this summer.