Many people do laundry for a very long time, but never understand how a washing machine works. Technology has come a long way since people were beating their clothing on the rocks at the river, but still, the washing machine works using simple principles.
The Wash Cycle
Two hoses are connected to the back of the washing machine: one for hot water and the other for cold. Inside the machine, an electrical solenoid opens and closes valves that allow water in and then shut it off. The temperature setting on the machine works by which valve opens. When set for cold, only the cold-water solenoid opens. When set for hot, the machine opens the hot water valve. For a medium setting, the washer will open both valves to let both hot and cold water into the tub. A sensor inside the machine tells it when the tub is full so that the rest of the wash cycle can proceed.
After the tub fills with water, the tub begins to agitate, or slowly churn in one direction and then the other. On a top loading machine, the tub has a center spindle called an agitator that forces clothes downward, cycling the laundry many times as it washes. The pressure created forces the water and detergent through the fabric in the laundry, getting the dirt out. For front loading washing machines, the agitation is done by tumbling the clothes on top of each other over and over again. In both cases, the weight of the clothes is instrumental in the washing process.
The washing machine tub itself has two components: the outside tub is what actually keeps the water from leaking out onto the floor. The inside tub is the part that spin. It also has holes in it that allows the water to flow out during the drain cycles. After the first agitation cycle, the washing machine activates an electrical pump that sucks the water out of the tub. It does this as the motor changes gears and spins the tub at high speed, using centrifugal force to help get as much water out as possible.
Once the tub is empty, it refills with clean water, agitates, and then drains to complete the rinse cycle.
“Dynamics of a Washing Machine’s Spin Cycle.” Georgia Institute of Technology. N.p., n.d. Web. 23 Aug. 2012. < http://helix.gatech.edu/Classes/ME2202/1999S3/Projects/Frederick/>
“EERE Roofus’ Solar and Efficient Home: How a Front-Loading Washing Machine Saves Water.” U.S. DOE Energy Efficiency and Renewable Energy (EERE) Home Page. N.p., n.d. Web. 23 Aug. 2012. http://www1.eere.energy.gov/kids/roofus/washing_machine.html