what is the function of antifreeze mixture ... please write it briefly
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Antifreeze is an additive that can alter the freezing and boiling points of the coolant in internal combustion engines that use water cooling. As the name implies, the main purpose of these additives is to prevent the liquid coolant from freezing, which can cause extensive engine damage. However, modern antifreeze also allows cooling systems to operate more efficiently by raising the boiling point of the coolant solution. Various substances have been used as antifreeze in the past, but most current automotive applications use ethylene glycol.
Ethylene glycol is the most widespread type of automotive antifreeze. Naturally colorless, it is typically dyed bright green.
Contents [hide]
1 The History of Antifreeze
2 How Does Antifreeze Work?
3 Alcohol as Antifreeze
4 Ethylene Glycol
4.1 Ethylene Glycol Water Mixture Ratios
5 Antifreeze Toxicity
5.1 Propylene Glycol
5.2 Glycerol
6 Checking Antifreeze
The History of Antifreeze
The history of antifreeze can be traced back to the early days of automotive engineering. The first automotive antifreeze was methyl alcohol, or methanol, which has a lower freezing point than water. That made it a good antifreeze, but other characteristics of methanol rendered it a poor automotive antifreeze.
In particular, alcohol tends to corrode the metals that it comes into contact with inside cooling systems. It also evaporated during normal use due to the fact that early radiators weren’t sealed since early water cooling systems weren’t pressurized.
After methyl alcohol, ethylene glycol was the next popular antifreeze to come along. This chemical was first synthesized in the middle of the 19th century, but it wasn’t used as an antifreeze until the second decade of the 20th century. At that time, it was marketed as “permanent” antifreeze due to the fact that it didn’t evaporate like alcohol.
By the end of World War II, during which it was widely used to cool military vehicles, ethylene glycol was the dominant type of automotive antifreeze. Ethylene glycol and pressurized cooling systems were so effective, in fact, that air cooled engines were all but killed off in automotive applications.
In recent history, a number of developments have been made in the field of antifreeze. Propylene glycol is now used in some applications due to a slightly lower toxicity, and some antifreeze mixtures also contain organic acid technology (OAT) chemicals.
Also see: The History of Antifreeze
How Does Antifreeze Work?
Antifreeze performs two primary functions:
lowering the freezing point of coolant
raising the boiling point of coolant
The main job of antifreeze is to lower the freezing point of coolant, which is important due to the way that water expands when it freezes. Since cooling systems are closed off, frozen coolant will tend to expand and cause catastrophic engine failure by deforming or cracking coolant passages in the cylinder block and head.
Water expands when it freezes, which can spell big trouble for a cooling system.
In addition to lowering the freezing temperature of water, antifreeze also raises its boiling temperature. Since the boiling point is also raised by the pressure in the cooling system, this allows engines to run hotter without overheating.
Alcohol as Antifreeze
In automotive usage, methanol is the type of alcohol that was used as antifreeze. Alcohol in general, and methanol in particular, is an excellent antifreeze, and it is still used in some windshield washer fluid solutions and other applications. However, it tends to cause corrosion when it comes into contact with metal inside cooling systems. It is particularly corrosive to aluminum, which is an issue to to the widespread use of aluminum in the manufacture of cylinder heads (and, to a lesser extent, blocks.)
Some windshield washer fluid uses alcohol as an antifreeze.
Ethylene Glycol
Although ethylene glycol first saw widespread use in the manufacture of high explosives, and it is still used widely in a variety of industr
Ethylene glycol is the most widespread type of automotive antifreeze. Naturally colorless, it is typically dyed bright green.
Contents [hide]
1 The History of Antifreeze
2 How Does Antifreeze Work?
3 Alcohol as Antifreeze
4 Ethylene Glycol
4.1 Ethylene Glycol Water Mixture Ratios
5 Antifreeze Toxicity
5.1 Propylene Glycol
5.2 Glycerol
6 Checking Antifreeze
The History of Antifreeze
The history of antifreeze can be traced back to the early days of automotive engineering. The first automotive antifreeze was methyl alcohol, or methanol, which has a lower freezing point than water. That made it a good antifreeze, but other characteristics of methanol rendered it a poor automotive antifreeze.
In particular, alcohol tends to corrode the metals that it comes into contact with inside cooling systems. It also evaporated during normal use due to the fact that early radiators weren’t sealed since early water cooling systems weren’t pressurized.
After methyl alcohol, ethylene glycol was the next popular antifreeze to come along. This chemical was first synthesized in the middle of the 19th century, but it wasn’t used as an antifreeze until the second decade of the 20th century. At that time, it was marketed as “permanent” antifreeze due to the fact that it didn’t evaporate like alcohol.
By the end of World War II, during which it was widely used to cool military vehicles, ethylene glycol was the dominant type of automotive antifreeze. Ethylene glycol and pressurized cooling systems were so effective, in fact, that air cooled engines were all but killed off in automotive applications.
In recent history, a number of developments have been made in the field of antifreeze. Propylene glycol is now used in some applications due to a slightly lower toxicity, and some antifreeze mixtures also contain organic acid technology (OAT) chemicals.
Also see: The History of Antifreeze
How Does Antifreeze Work?
Antifreeze performs two primary functions:
lowering the freezing point of coolant
raising the boiling point of coolant
The main job of antifreeze is to lower the freezing point of coolant, which is important due to the way that water expands when it freezes. Since cooling systems are closed off, frozen coolant will tend to expand and cause catastrophic engine failure by deforming or cracking coolant passages in the cylinder block and head.
Water expands when it freezes, which can spell big trouble for a cooling system.
In addition to lowering the freezing temperature of water, antifreeze also raises its boiling temperature. Since the boiling point is also raised by the pressure in the cooling system, this allows engines to run hotter without overheating.
Alcohol as Antifreeze
In automotive usage, methanol is the type of alcohol that was used as antifreeze. Alcohol in general, and methanol in particular, is an excellent antifreeze, and it is still used in some windshield washer fluid solutions and other applications. However, it tends to cause corrosion when it comes into contact with metal inside cooling systems. It is particularly corrosive to aluminum, which is an issue to to the widespread use of aluminum in the manufacture of cylinder heads (and, to a lesser extent, blocks.)
Some windshield washer fluid uses alcohol as an antifreeze.
Ethylene Glycol
Although ethylene glycol first saw widespread use in the manufacture of high explosives, and it is still used widely in a variety of industr
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Hey,
An antifreeze is an additive which lowers the freezing point of a water-based liquid and increases its boiling point. An antifreeze mixture is used to achieve freezing-point depression for cold environments and also achieves boiling-point elevation ("anti-boil") to allow higher coolant temperature. Freezing and boiling points are colligative properties of a solution, which depend on the concentration of the dissolved substance.
Because water has good properties as a coolant, water plus antifreeze is used in internal combustion engines and other heat transfer applications, such as HVAC chillersand solar water heaters. The purpose of antifreeze is to prevent a rigid enclosure from bursting due to expansion when waterfreezes. Commercially, both the additive (pure concentrate) and the mixture (diluted solution) are called antifreeze, depending on the context. Careful selection of an antifreeze can enable a wide temperature range in which the mixture remains in the liquid phase, which is critical to efficient heat transfer and the proper functioning of heat exchangers.
Salts are frequently used for de-icing, but salt solutions are not used for cooling systems because they can cause severe corrosion to metals. Instead, non-corrosive antifreezes are commonly used for critical de-icing, such as for aircraft wings.
An antifreeze is an additive which lowers the freezing point of a water-based liquid and increases its boiling point. An antifreeze mixture is used to achieve freezing-point depression for cold environments and also achieves boiling-point elevation ("anti-boil") to allow higher coolant temperature. Freezing and boiling points are colligative properties of a solution, which depend on the concentration of the dissolved substance.
Because water has good properties as a coolant, water plus antifreeze is used in internal combustion engines and other heat transfer applications, such as HVAC chillersand solar water heaters. The purpose of antifreeze is to prevent a rigid enclosure from bursting due to expansion when waterfreezes. Commercially, both the additive (pure concentrate) and the mixture (diluted solution) are called antifreeze, depending on the context. Careful selection of an antifreeze can enable a wide temperature range in which the mixture remains in the liquid phase, which is critical to efficient heat transfer and the proper functioning of heat exchangers.
Salts are frequently used for de-icing, but salt solutions are not used for cooling systems because they can cause severe corrosion to metals. Instead, non-corrosive antifreezes are commonly used for critical de-icing, such as for aircraft wings.
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