Food is one of the primary human needs. It provides us sustenance, energy, and nourishment. But the world has limited natural resources, and the foods tend to be extremely perishable. It gave rise to a very crucial need for keeping food fresh for a longer period of time. With the goal of slowing the process of fresh produce rotting, and preserving them for a later time, the latent need for a technology rose up, which has slowly become a part and parcel of everyone’s life.
It was to no one’s surprise that cooling could without a doubt prevent food from wilting, slow the process of fresh produce decomposing, and increase their shelf life. One of the first officially used cooling systems involved the use of basic ice. But the need for an artificial process was soon felt.
The History Behind a Refrigerator
Mid eighteenth century saw the beginning of the first artificial refrigeration systems. But the technology was fully developed in the early 1800s. Now, a refrigerator, also called a fridge, is an electronic appliance that uses thermal insulation technology to convert heat received from the outer environment and bring the temperature down to provide excellent airflow inside the storage compartments.
The first-ever fully functional refrigeration system was built in 1834. It used the vapor-compression system to keep the compartments close. We will soon get to the technical aspects of how a refrigerator functions. Commercially ice-making also started later in the century. In the year 1913, the journey of the refrigerator as a home appliance took off. The first electric refrigerator for domestic use was invented by Fred W. Wolf, an American, and was called the Domelre, short for the Domestic Electric Refrigerator. In spite of the failure of his model, he appeared to have had some success with a design innovation he had come up with - the ice cube tray.
Frigidaire introduced a self-contained unit in 1923. By the 1930s, the refrigerator market had expanded significantly due to Freon's introduction in the 1920s. Separate freezers which were larger than necessary for just ice cubes were introduced in 1940, specifically designed for home freezers. The once-luxury item of frozen food has become ubiquitous.
Since the 1700s, for nearly a century and a half, refrigerators have now become a part and parcel of almost every other household in the world. But how does a refrigerator keep your food safe? Low temperatures are needed to minimize the reproduction rate of harmful bacteria around food in order to keep it fresh. Refrigerators work by transferring heat from inside to outside, which is why the back side of the fridge feels warm if your hand is placed near the metal pipes. But the process involves a lot of essential parts and equipment. Let us go through each of them one by one.
Components of Refrigerator
Refrigerators are powered by their compressors. They work with refrigerants, which is a compound typically found in either a fluid or gaseous state. It readily absorbs heat from the environment and can provide refrigeration or air conditioning when combined with other components such as compressors and evaporators. Refrigerant is circulated throughout the system and pressure is added to the warm part of the circuit, making the refrigerant hot. Compressors use heat and pressure to increase the temperature and pressure of the vaporized refrigerant. Compressors used in refrigeration are of different types. A single refrigeration unit can have three different types of compressors: reciprocating, rotary and centrifugal.
When the compressor raises the pressure, the refrigerant becomes gaseous and heats up. The cooled air is then passed through the coils outside the refrigerator. Due to its warmer temperature, the gas in the coils is cooled and returns to liquid form when it comes in contact with the air outside. In the interior of the unit, the high-pressure liquid is directed through the coils, and after passing through them, the refrigerant absorbs the heat from the air inside. The refrigerant then evaporates and is then sent back for another cycle of evaporation and compressor.
In a refrigeration system heat is transferred to another medium, such as air or water, from the refrigerant with the help of condensers. Condensers are made up of coiled tubes. The compressor of a domestic refrigerator is located at the back. The condenser condenses vaporized refrigerant, converting it back to a liquid state.
Refrigeration systems contain an evaporator for cooling. By absorbing heat, it cools the contents of the cooling appliance. Evaporators are found inside refrigerators and they are responsible for keeping items in the refrigerator cold. Refrigerants, as they turn from liquids to gases through evaporation, cool the surrounding air, producing the appropriate environment to store food. Evaporators are located in the freezing compartment of the domestic refrigerator since they are mostly responsible for making ice.
Typically consists of two apparatus called capillary tube and thermostat. Combinedly, it is responsible for flowing the liquid refrigerant throughout the device. A thermostatic expansion valve controls the valve's temperature. Depending on the temperature you set, it responds. Essentially, capillary tubes are thin pieces of tubing used for expansion. During operation of the evaporator, liquid refrigerant is routed through a capillary tube and sprayed into the low-pressure environment. In order to control cooling, the thermostat monitors the temperature and turns on and off the compressor based on that information. Whenever the sensor senses that the refrigerator is cold enough, the compressor is shut off. Upon sensing too much heat, the thermostat switches on the compressor to begin cooling again.
How Does it Work
But how do all these separate components come together to fulfill one goal, keeping food fresh?
Let us see a streamlined description of the entire operating procedure of refrigerators.
A liquid that circulates inside refrigerators changes into a gas as it escapes. This process, called evaporation, cools the surrounding area and produces the desired effect.
An outlet known as the capillary tube reduces pressure so that evaporation can begin and the refrigerant can come into contact with air and become a gas. The content of an aerosol can represent the liquid side, the capillary tube represents the outlet, and the open area represents the evaporator. As soon as the container contents are released into the open space with lower pressure, they turn from liquid to gas.
The refrigerant gaseous in a refrigerator has to be compressed near its liquid state to keep it running, so it must be cooled again at a higher temperature and pressure. Compressors are used here.
The compressed gas will be hot and under high pressure, once the compressor has finished its work. Condensers are mounted on the back of refrigerators to cool their contents through ambient air. Inside the condenser, a liquid is formed from the gas as it cools off (still under high pressure).
In the end, the liquid refrigerant is circulated back to the evaporator, where the process starts over once more.
What does a Refrigerator Provide?
So, what does a refrigerator ultimately provide you aside from the basic facility of cooling?
Increasing Shelf Life: Food preservation is the prime requirement that comes as a given with ant refrigerating apparatus. Keeping your food and edibles at optimal temperature, not only delays the entire procedure of rotting and wilting. But also, help to keep the spread and growth of bacteria by keeping them in a cold intact environment. Foods ranging from fresh produce to raw meat and fish to even cooked or packaged foods can be stored for a longer period of time if preserved in proper conditions. However, modern fridges like LG refrigerators have advanced technology that keeps the food fresh in a special way!
Cooling: Cooling is also another basic facility that comes with refrigerators. But what is more fascinating is how the cooling requirements can change over time. And refrigerators give us the choice to control it as well. Yes, it is necessary to keep the foods and perishables in a cool environment to maintain their freshness, but what about the summer seasons? Extra care is needed to preserve the foods and then comes into play the ability to store them in a cooler environment. Not to mention, water, drinks, and ice cubes are also a must in summer that can be easily stored cold in refrigerators or freezers. However, the more strong the cooling system is in a fridge, the more it keeps the food fresh. And from time to time the cooling system has evolved and has added more value.
Wallet-Friendly: Refrigerators are not only an essential home appliance, but they also make living your day-to-day life more cost effective. With the facility to store foods fresh for a long time, now you can buy weeks or even months’ worth of groceries and store them adequately. They also prevent daily food wastage by keeping them fresh and edible for a later time than prepared. Hence, they are a good investment with solid long-term benefits.
Fine-Tune Adjustments: Be it any season, any food, or perishable, refrigerators provide you with the facility to customize the compartment temperature as deemed necessary.
The market does not lack options when you are looking for refrigerators. From all sizes mini to large freezers, there is always a solution to all of your requirements. Top-mount, bottom-mount, double door, glass door, eco-friendly, etc. you name it!
Refrigerators had quite a journey over the last century, and today we have state-of-the-art facilities available at the tip of our fingers. Keeping food safe has been made easy, making refrigerators an essential for us.