Refrigerators or refrigerators have a bimetal for temperature control.
The notion of bimetal is formed with the prefix bi- and the noun metal . While the meaning of the compositional element bi- is “twice” or “two” , a metal is a chemical element that is characterized by its brightness and its ability to conduct electricity and heat .
A device composed of two metal sheets that are joined together and expand at different thermal values is called bimetal . Thanks to its characteristics, bimetal is used for temperature control.
How a bimetal works
Bimetal is an object made up of layers of two different metals. As these metals have dissimilar thermal expansion or expansion coefficients , they transform the temperature change into a mechanical type movement .
In this way, bimetals are often used as thermostats . It can be a disc or a strip : when the temperature changes, the bimetal tends to bend towards the side that has a lower expansion coefficient.
Its use in refrigerators or refrigerators
A refrigerator , refrigerator , icebox or refrigerator is an appliance that generates cold to enable the preservation of food or other products inside. These devices have a bimetal that acts as a switch with temperature variations.
In the event of a thermal change, whether upward or downward, the bimetal flexes due to the aforementioned expansion coefficients of its metal layers. This element works in conjunction with electrical resistance .
When there is a lot of ice on the appliance's evaporator, defrosting needs to be promoted to maintain efficiency. Excess ice is associated with a very low temperature, which causes the bimetal to finally bend and close the circuit responsible for activating the electrical resistance to begin the defrosting process.
On the contrary, if there is no longer ice in the evaporator and the temperature rose to a certain level, the bimetal flexes to the opposite side, causing the circuit to open and causing the resistance to disconnect.
Each bimetal works at a specific factory-defined temperature (that is, it bends to one side or the other at a certain number of degrees). With bimetal, energy is saved and accidents are avoided since the refrigerator motor does not work when it is not necessary.
Bimetallic coins show two different metals.
bimetallic coin
A bimetallic coin is made up of two metal parts that can be differentiated. This feature contributes to reducing production costs and discourages attempts to melt them, since the higher-value metal appears covered or surrounded by a cheaper one.
Many countries currently have bimetallic coins in circulation. The 1 and 2 euro coins, for example, are bimetallic. So are the £ 1 and £2 coins.
Argentine pesos , Brazilian reals , and Peruvian soles are other currencies with bimetallic coins. In some cases, these coins are valued objects by collectors due to their rarity or age.