A cube ice maker is a machine or system which can produce ice cubes.
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Cube ice machines are classified as small ice machines, in contrast to tube ice machines, flake ice machines and other ice machines. Normally, its daily capacity ranges from 30 kg (65 Lbs) to 1755 kg (3900 Lbs). Since the emergence of cube ice machines in 1970s they have evolved into the diverse family of ice machines which exist today.
Cube ice machines commonly are seen as vertical modular devices. The upper part is an evaporator, while the lower part is an ice bin. The refrigerant circulates inside pipes of sale-contained evaporator, where it conducts the heat exchange with water, and freezes the water into ice cubes. When the water is thoroughly frozen into ice, it will be released automatically, and fall into the ice bin underneath.
The ice bin can also be equipped with compressors. Generally cube ice machines with capacities over 320 kg have built-in compressors in the ice bin for storage prior to sales, when demands are large.
Cube ice is created in a cubic shape, with each edge usually between 15mm and 35mm. The surface area of every ton of cube ice is approximately 1383 square metres.
All refrigeration equipments are made of four key components; they are the evaporator, the condenser, the compressor and the throttle valve. Ice machines are not exceptions either. The function of compressor is to compress low pressure refrigerant vapour to high pressure vapour, and delivery it to the condenser, where the high pressure vapour is condensed into high pressure liquid, and drained out through the throttle valve to become low pressure liquid, and conducting heat exchanging in the evaporator afterwards. This is one complete refrigeration cycle.
Most compressors are either positive displacement compressors or radial compressors:
Positive displacement compressors are currently the most efficient compressor, and have the largest refrigerating effect per single unit (400RT-2500RT). They have high tolerance of power supplies, and can be 380V, 1000V, or even higher. The principle behind positive displacement compressors is utilizing a turbine to compress refrigerant into high pressure vapor.
Positive displacement compressors are of 4 main types- screw compressor, rolling piston compressor, reciprocating compressor, rotary compressor.
Screw compressors can yield the largest refrigerating effect among positive displacement compressors, with its refrigerating capacity normally ranging from 50RT to 400RT. Screw compressor also can be divided to single screw type and dual screw type. Dual screw type is more often seen in use because they are very efficient.
Rolling piston compressor and reciprocating compressor have similar refrigerating effects, and maximum refrigerating effect can reach 600Kw. Danfoss compressors are widely regarded as the best in this category.
Reciprocating compressors are the most commonly seen compressor because its technology is mature and reliable. Its refrigerating effect ranges from 2.2Kw to 200Kw. It compresses gas by utilizing a piston pushed by a crank shaft.
Rotary compressor, mainly used in air conditioning equipment, has a very low refrigerating effect, normally not exceeding 5Kw. They work by compressing gas using a piston pushed by a rotor which spins in an isolated room.
All condensers can be classified as three types, air-cooling, water cooling, and evaporative cooling:
Air cooling condenser uses air as the heat conducting media by blowing air through the surface of condensers, which carries heat away from the high pressure, high temperature refrigerant vapour.
Water cooling condenser uses water as the heat conducting media to cooling refrigerant vapour to liquid.
Evaporative condenser cools the refrigerant vapour by heat exchange between the evaporator pipes and the evaporated water which sprayed on the surface of the pipes. This type of condenser is capable of working in warm environments and they are very efficient and reliable.