‘Containerised’ block ice plants
Topographical names in Iceland and elsewhere in temperate climates imply that, long before the advent of mechanised refrigeration, ice was collected in the mountains during the winter and stored in the lowlands for warmer times.
Storage rooms were refrigerated with ‘jackets’, lining the inside of the insulated walls and filled with crushed ice and salt. Evidence is found as far south as on Hong Kong Island. The invention of block ice plants – the first mechanical refrigerating technique – early in the 20th Century changed all this permanently.
Block ice plants are elemental, user-friendly and easy to maintain. In state-of-the-art plants, brine – the cold carrier – is refrigerated in a heat exchanger outside the brine tank, while in conventional designs cooling is effected with a coil submerged in the brine within the tank. The new arrangement greatly reduced the size of the brine tank, the volume of brine and the quantity of refrigerant, and made the plants less expensive to fabricate and easier to maintain.
State-of-the-art block ice plants can work with any environment-friendly refrigerant, such as R134a and R404a. The low-tech equipment is assembled into a compact Refrigerating Unit, with access to the individual components from all sides for servicing. If electric power is unreliable, insufficient or simply too expensive, the plants can be primed with combustion engines fuelled with oil or gas. In conventional plants, bigger quantities of refrigerant, the less expensive R717 (ammonia) is preferred.
Half of the population in rural areas of the Developing World inhabits coastal regions and rims of inland waterways. Refrigerated storage facilities seldom exist in these parts and perishable harvests – marine, aquatic or agricultural – are preserved with ice. Crushed block ice is spread on the goods to prolong shelf life and cut-to-size blocks are vended to households and food markets, door-to-door from basic transport equipment.
Well equipped mechanical workshops, capable of elaborate fabrication work, exist in all major communities in the Developing World. IceBits ehf of Iceland provides drawings and specifications for do-it-yourself fabrication of small ‘containerised’ block ice plants. The plants are self-contained and can be relocated with standard transport equipment, and are self-sufficient, requiring only oil or gas fuel as power source. A makeshift thatched roof protect the plants against sun and rain.
