The New Student's Reference Work/Ice-Machines and Ice-Cutting Tools

Ice-Machin′es and Ice-Cut′ting Tools. There are several types and many varying manufactures of ice-making machines, all depending for success upon the principle that cold is produced by the expansion of compressed air, gas or a liquified vapor, as ammonia. The machines most used are those known as ammonia machines because of their use of anhydrous or waterless ammonia. In such machines there is an evaporator or congealer, in which the ammonia is vaporized. This vapor is then compressed by a pump into liquid, the process being aided by a stream of cold water. This part of the process is merely economical, making it possible to use the same ammonia over and over. The ice is manufactured by running the ammonia into coils where it vaporizes. These coils are led into tanks of strong brine. The evaporation in the coils causes intense cold, and the brine is deprived of its heat or made cold in much the same way that water or a room may be heated by pipes or coils carrying steam. That is, they would be made cold instead of warm, of the pipes which carry steam were made to carry this ammonia vapor. Cans of water, set in this chilled brine, are thus frozen. The cans are thus the molds of the ice-blocks that are turned out, and these are of various convenient sizes. The brine is used to surround the cans, because it will still remain liquid under a degree of cold that is sufficient to freeze the water in the cans that are immersed in it. The vaporized ammonia is again gathered and compressed, and again used in producing cold. The pumps, compressors and other machinery of the modern ice-machine are the accessories merely that make practical the industry of producing ice according to the old and well-known law that rapid evaporation produces cold, as does also the sudden release of compressed air or gas. The modern economy known as cold storage is the result of the processes above described, save that the coils to carry ammonia are placed about the sides of large storage rooms and reduce the temperature of the air, as in ice-making they reduce that of the brine in tanks. Ice-cutting tools are such as are used in gathering—“harvesting”—the natural ice in rivers, lakes and pools, so as to store it for summer use. The “planer” is used to clear the ice-surface of snow. It is a one-horse scraper. The “marker” then comes into use to lay out the intended field into cuttings. It is a kind of plow, drawn by a horse, with several shares which cut marks upon the ice. The ice-cutter is a similar machine whose shares cut deeper than those of the marker, and, if the ice is thick, it is run several times in the same cuttings, so that the ice is finally nearly cut through. The cross-cuttings, by which the ice is cut into blocks or slabs, are usually made by hand. Other tools are used to detach the blocks and seize or push them, while floating, toward the chute or elevator of the ice-house.