Icemaker
An icemaker, ice generator, or ice machine may refer to either a consumer device for making ice, found inside a home freezer, a stand-alone appliance for making ice, or an industrial machine for making ice on a large scale. The term "ice machine" usually refers to the stand-alone appliance.
The ice generator is the part of the ice machine that actually produces the ice. This includes the evaporator and any associated drives/controls/subframe that are directly involved with making and ejecting the ice into storage. When most people refer to an ice generator, they mean this ice-making subsystem alone, minus refrigeration.
An ice machine, however, particularly if described as 'packaged', will typically be a complete machine including refrigeration, controls, and dispenser, requiring only connection to power and water supplies.
The term icemaker is more ambiguous, with some manufacturers describing their packaged ice machine as an icemaker, while others describe their generators in this way.
History
In 1748, the first known artificial refrigeration was demonstrated by William Cullen at the University of Glasgow. Mr. Cullen never used his discovery for any practical purposes. This may be the reason why the history of the icemakers begins with Oliver Evans, an American inventor who designed the first refrigeration machine in 1805. In 1834, Jacob Perkins built the first practical refrigerating machine using ether in a vapor compression cycle. The American inventor, mechanical engineer and physicist received 21 American and 19 English patents and is considered today the father of the refrigerator.In 1844, an American physician, John Gorrie, built a refrigerator based on Oliver Evans' design to make ice to cool the air for his yellow fever patients. His plans date back to 1842, making him one of the founding fathers of the refrigerator. Unfortunately for John Gorrie, his plans of manufacturing and selling his invention were met with fierce opposition by Frederic Tudor, the Boston “Ice King”. By then, Tudor was shipping ice from the United States to Cuba and was planning to expand his business to India. Fearing that Gorrie’s invention would ruin his business, he began a smear campaign against the inventor. In 1851, John Gorrie was awarded U.S. Patent 8080 for an ice machine. After struggling with Tudor's campaign and the death of his partner, John Gorrie also died, bankrupt and humiliated. His original icemaker plans and the prototype machine are held today at the National Museum of American History, Smithsonian Institution in Washington, D.C.
In 1853, Alexander Twining was awarded for an icemaker. Twining’s experiments led to the development of the first commercial refrigeration system, built in 1856. He also established the first artificial method of producing ice. Just like Perkins before him, James Harrison started experimenting with ether vapor compression. In 1854, James Harrison successfully built a refrigeration machine capable of producing 3,000 kilograms of ice per day and in 1855 he received an icemaker patent in Australia, similar to that of Alexander Twining. Harrison continued his experiments with refrigeration. Today he is credited for his major contributions to the development of modern cooling system designs and functionality strategies. These systems were later used to ship refrigerated meat across the globe.
In 1867, Andrew Muhl built an ice-making machine in San Antonio, Texas, to help service the expanding beef industry before moving it to Waco in 1871. In 1873, the patent for this machine was contracted by the Columbus Iron Works, which produced the world's first commercial icemakers. William Riley Brown served as its president and George Jasper Golden served as its superintendent.
In 1876, German engineer Carl von Linde patented the process of liquefying gas that would later become an important part of basic refrigeration technology. In 1879 and 1891, two African American inventors patented improved refrigerator designs in the United States.
In 1902, the Teague family of Montgomery purchased control of the firm. Their last advertisement in Ice and Refrigeration appeared in March 1904. In 1925, controlling interest in the Columbus Iron Works passed from the Teague family to W.C. Bradely of W.C. Bradley, Co.
Jurgen Hans is credited with the invention of the first ice machine to produce edible ice in 1929. In 1932 he founded a company called Kulinda and started manufacturing edible ice, but by 1949 the business switched its central product from ice to central air conditioning.
The ice machines from the late 1800s to the 1930s used toxic gases such as ammonia, methyl chloride, and sulfur dioxide as refrigerants. During the 1920s, several fatal accidents were registered. They were caused by the refrigerators leaking methyl chloride. In the quest of replacing dangerous refrigerants – especially methyl chloride – collaborative research ensued in American corporations. The result of this research was the discovery of Freon. In 1930, General Motors and DuPont formed Kinetic Chemicals to produce Freon, which would later become the standard for almost all consumer and industrial refrigerators. The original "Freon" produced at this time was chlorofluorocarbon, a moderately toxic gas causing ozone depletion.
Principle of ice making
All refrigeration equipment is made of four key components; the evaporator, the condenser, the compressor and the throttle valve. Ice machines all work the same way. The function of the compressor is to compress low-pressure refrigerant vapor to high-pressure vapor, and deliver it to the condenser. Here, the high-pressure vapor is condensed into high-pressure liquid, and drained out through the throttle valve to become low-pressure liquid. At this point, the liquid is conducted to the evaporator, where heat exchanging occurs, and ice is created. This is one complete refrigeration cycle.Consumer icemakers
Freezer icemakers
Automatic icemakers for the home were first offered by the Servel company around 1953. They are usually found inside the freezer compartment of a refrigerator. They produce crescent-shaped ice cubes from a metal mold. An electromechanical or electronic timer first opens a solenoid valve for a few seconds, allowing the mold to fill with water from the domestic cold water supply. The timer then closes the valve and lets the ice freeze for about 30 minutes. Then, the timer turns on a low-power electric heating element inside the mold for several seconds, to melt the ice cubes slightly so they will not stick to the mold. Finally, the timer runs a rotating arm that scoops the ice cubes out of the mold and into a bin, and the cycle repeats. If the bin fills with ice, the ice pushes up a wire arm, which shuts off the icemaker until the ice level in the bin goes down again. The user can also lift up the wire arm at any time to stop the production of ice.Later automatic icemakers in Samsung refrigerators use a flexible plastic mold. When the ice cubes are frozen, which is sensed by a Thermistor, the timer causes a motor to invert the mold and twist it so that the cubes detach and fall into a bin.
Early icemakers dropped the ice into a bin in the freezer compartment; the user had to open the freezer door to obtain ice. In 1965, Frigidaire introduced icemakers that dispensed from the front of the freezer door. In these models, pressing a glass against a cradle on the outside of the door runs a motor, which turns an auger in the bin and delivers ice cubes to the glass. Most dispensers can optionally route the ice through a crushing mechanism to deliver crushed ice. Some dispensers can also dispense chilled water.
Fresh food compartment icemakers
Some newer refrigerators have the icemaker located in the fresh food compartment. In order to function properly, the icemaker compartment should keep temperature inside around and needs to be properly sealed from the outside.Portable icemakers
Portable icemakers are units that can fit on a countertop. They are the fastest and smallest icemakers on the market. The ice produced by a portable icemaker is bullet-shaped and has a cloudy, opaque appearance. The first batch of ice can be made within 10 minutes of turning the appliance on and adding water. The water is pumped into a small tube with metal pegs immersed in the water. Because the unit is portable, water must be filled manually. The water is pumped from the bottom of the reservoir to the freeze tray. The pegs use a heating and cooling system inside to freeze the water around them and then heat up so the ice slips off the peg and into the storage bin. Ice begins to form in a matter of minutes, however, the size of ice cubes depends on the freezing cycle - a longer cycle results in thicker cubes. Portable icemakers will not keep the ice from melting, but the appliance will recycle the water to make more ice. Once the storage tray is full, the system will turn off automatically.Built-in and freestanding icemakers
Built-in icemakers are engineered to fit under a kitchen or bar counter, but they can be used as freestanding units. Some produce crescent-shaped ice like the ice from a freezer icemaker; the ice is cloudy and opaque instead of clear, because the water is frozen faster than in others which are clear cube icemakers. In the process, tiny air bubbles get trapped, causing the cloudy appearance of the ice. However, most under-counter ice makers are clear ice makers in which the ice is missing the air bubbles, and therefore the ice is clear and melts much slower.Industrial icemakers
Commercial ice makers improve the quality of ice by using moving water. The water is run down a high nickel content stainless steel evaporator. The surface must be below freezing. Salt water requires lower temperatures to freeze and will last longer. Generally used to package seafood products. Air and undissolved solids will be washed away to such an extent that in horizontal evaporator machines the water has 98% of the solids removed, resulting in very hard, virtually pure, clear ice. In vertical evaporators the ice is softer, more so if there are actual individual cube cells. Commercial ice machines can make different sizes of ice like flakes, crushed, cubes, octagons, and tubes.When the sheet of ice on the cold surface reaches the desired thickness, the sheet is slid down onto a grid of wires, where the sheet's weight causes it to be broken into the desired shapes, after which it falls into a storage bin.