Located in the historic dock area of Grimsby, UK, the Grimsby Ice Factory still houses some of the original ammonia ice making equipment, used over 100 years ago to produce crushed ice for the town’s trawlers. The factory is the sole surviving example of this type of ice factory with its equipment still intact in the original context.
The Grimsby Ice Factory was built between 1898 and 1901 by the Grimsby Ice Company to produce Ice for Grimsby’s fishing fleet. The demand for ice was so great during that period that, despite the existence of a few ice factories in town, several thousands of tonnes of ice had to be imported from Norway. At its peak, the Grimsby Ice Factory had the capacity to produce 1117 tonnes of ice per day.
Historical ammonia technology
Originally steam driven by Lancashire boilers, the factory utilised four Pontifex horizontal double acting ammonia compressors, driven by vertical triple-expansion engines. At that time, ice production was divided between the “can” method (in which metal cans of water passed through freezing brine) and the “cell” method (in which brine circulated around fixed cells in the walls). Although the “cell” method allowed for the production of clear ice, it was more labour intensive. As the aesthetic benefits of clear ice were of little value in the fishing industry, by the 1920’s all production had switched to the “can” method.
In 1933, due to growing demand for ice, the factory decided to increase production by electrifying the plant. The steam plant was replaced by electrical generators supplied by Metropolitan-Vickers of Manchester. J&E Hall of Dartford was contracted to replace the two Linde ammonia compressors with four four-cylinder vertical valve ammonia compressors. These were the largest machines produced by J&E Hall at the time. Today, these compressors, which still remain inside the factory, are the sole surviving example of this type of equipment.
Ice production method
Liquid ammonia was fed at high pressure to the pumping stations in the Tank House, and then expanded to low pressure, reducing its boiling point to about -20°C. After that, the liquid ammonia refrigerant was pumped to cooling coils, which rested in tanks of calcium chloride brine, where the partial evaporation of the ammonia reduced the temperature of the brine. In the meantime, the mixture of gas and liquid was returned to the pumping house, where the gas was separated and fed back to the pumping house.
In the tank rooms, metal cans, suspended from a steel frame, were filed with fresh water drawn from boreholes beneath the factory. Once filled, the cans were lowered into the brine, chilled to -13 °C, and pushed forward to make room for the next row of cans. The tanks were covered by wooden lids to form a floor surface. Evaporator coils within the tanks absorbed heat from the water in the cans and turned it to ice. As the cans reached the far end of the tank room, they were lifted from the brine and lowered into a thawing tank, which was heated by hot gas from the compressors. As the ice thawed, it floated to the surface of the thawing tank and was tipped out by a crane and moved to a crusher. The crushed ice was then ready to be delivered to the waiting trawlers.
Grimsby Ice Factory today
Due to the decline of the fishing industry and advances in flake ice production, the Grimsby Ice Factory became redundant and finally closed its doors in July, 1990. Today, the historic factory is listed as Grade Two Star by the English Heritage. Recognised nationally as a significant heritage asset, the building cannot be demolished. The Great Grimsby Ice Factory Trust, together with the support of organisations such as the Prince’s Regeneration Trust and the Architectural Heritage Fund, is working to find a sustainable new use for the building.
Historical ammonia technology
Originally steam driven by Lancashire boilers, the factory utilised four Pontifex horizontal double acting ammonia compressors, driven by vertical triple-expansion engines. At that time, ice production was divided between the “can” method (in which metal cans of water passed through freezing brine) and the “cell” method (in which brine circulated around fixed cells in the walls). Although the “cell” method allowed for the production of clear ice, it was more labour intensive. As the aesthetic benefits of clear ice were of little value in the fishing industry, by the 1920’s all production had switched to the “can” method.
In 1933, due to growing demand for ice, the factory decided to increase production by electrifying the plant. The steam plant was replaced by electrical generators supplied by Metropolitan-Vickers of Manchester. J&E Hall of Dartford was contracted to replace the two Linde ammonia compressors with four four-cylinder vertical valve ammonia compressors. These were the largest machines produced by J&E Hall at the time. Today, these compressors, which still remain inside the factory, are the sole surviving example of this type of equipment.
Ice production method
Liquid ammonia was fed at high pressure to the pumping stations in the Tank House, and then expanded to low pressure, reducing its boiling point to about -20°C. After that, the liquid ammonia refrigerant was pumped to cooling coils, which rested in tanks of calcium chloride brine, where the partial evaporation of the ammonia reduced the temperature of the brine. In the meantime, the mixture of gas and liquid was returned to the pumping house, where the gas was separated and fed back to the pumping house.
In the tank rooms, metal cans, suspended from a steel frame, were filed with fresh water drawn from boreholes beneath the factory. Once filled, the cans were lowered into the brine, chilled to -13 °C, and pushed forward to make room for the next row of cans. The tanks were covered by wooden lids to form a floor surface. Evaporator coils within the tanks absorbed heat from the water in the cans and turned it to ice. As the cans reached the far end of the tank room, they were lifted from the brine and lowered into a thawing tank, which was heated by hot gas from the compressors. As the ice thawed, it floated to the surface of the thawing tank and was tipped out by a crane and moved to a crusher. The crushed ice was then ready to be delivered to the waiting trawlers.
Grimsby Ice Factory today
Due to the decline of the fishing industry and advances in flake ice production, the Grimsby Ice Factory became redundant and finally closed its doors in July, 1990. Today, the historic factory is listed as Grade Two Star by the English Heritage. Recognised nationally as a significant heritage asset, the building cannot be demolished. The Great Grimsby Ice Factory Trust, together with the support of organisations such as the Prince’s Regeneration Trust and the Architectural Heritage Fund, is working to find a sustainable new use for the building.
MORE INFORMATION
Apr 22, 2013, 12:46
Related stories
Sign up to our Newsletter
Fill in the details below
