Study of Refrigerator and Microwave OvenCOURSE: ELECTRONIC SHOPCOURSE INSTRUCTOR: MR. A.H.M SHATIL

STUDENT NAME: BILLAH, MD. MOSTAKIMSTUDENT ID: 12-21491-2

Refrigerator• A device that produces work by moving

heat from high to low temperature.

• Temperature range for perishable food storage is 3 to 5 °C (37 to 41 °F).

History of Refrigerator• Refrigerators for home and domestic use were invented by Fred W.

Wolf of Fort Wayne in 1913.

Basic Concept of Refrigerator• Pass a colder liquid continuously around

the object that is to be cooled.

Components of Refrigerator & Working Principle• Main components:

• Compressor, • Condenser, • Evaporator and • Throttling device.

Throttling Device• Obstructs the flow of liquid

• Cold liquid is produced with the help of this device

• Restricts the flow, which causes a tremendous pressure drop.

Evaporator - Heat Absorption Process• During the heat absorption process, the

refrigerant further evaporates and transforms into pure vapor.

• Heat exchanger is required to carry the cold refrigerant over the body.

Compressor• Raises the pressure back to its

initial level.

• Compressing gas, along with pressure.

Condenser• Heat exchanger

• Fitted outside of the refrigerator

Advantages• Store food for long time and protects the food from microbes.

• Keep the objects cool and thus protects the food from heat and direct sunlight

Disadvantages• Use large amount of electricity.

• Refrigerator gas causes global warming.

Microwave Oven• Heats and cooks food by exposing

it to electromagnetic radiation in the microwave spectrum.

• Quick and efficient.

History of Microwave Oven• Percy Spencer invented the first microwave oven after World War II

from radar technology.

Working Principle of Microwave Oven• Magnetron takes electricity from the

power outlet and converts it into high-powered radio waves.

• Magnetron blasts these waves into the food compartment.

• Microwaves bounce back and forth off the reflective metal walls.

• Microwaves travel through food, they make the molecules inside it vibrate more quickly.

Advantages• Cooks many foods in about 1/4th of the time necessary on a gas

burner.

• Saves time in heating frozen foods.

Disadvantages• Cannot cook many popular food.

Thankyou