Many people are dependent on their morning cup of coffee and the aroma of freshness that it brings to “perk” them up. The National Coffee Association has reported that coffee consumption has increased by more than 9 percent in the past six years.
A modern coffee maker is relatively a simple device with a reservoir that heats water, a tube to carry hot water to the drip area where it falls on the ground coffee and a container to hold and warm the coffee. The coffee maker has a resistive heating element, a coiled wire, similar to a light bulb. The heating element boils the water and also keeps the coffee warm after it is brewed. The heating element presses against the warming plate so that the heat transfer is uniform on the plate. The switch turns the power to the heating element on and off. A temperature sensor prevents the heating element from overheating and turns the coil back on, when it drops below the desired temperature. The coffee maker also has a one-way valve. The one-way valve allows cold water into the aluminum tube and forces the bubbles of boiling water to flow up the black tube.
When cold water is poured into a coffee maker, it flows from the bucket through the hole at the bottom into the tube. Due to gravity, the water then flows through the one-way valve into the aluminum tube in the heating element, and then partially up through the black tube. When the switch is turned on, the heating element starts heating the aluminum tube, and eventually the water in the tube boils. When the water boils, the bubbles rise up in the black tube. The tube is small enough while the bubbles are big enough to allow a column of water to ride upward on top of the bubble. The water flows out of the end of the black tube to drip into the coffee.
For a coffee lover, a coffee machine is an essential kitchen appliance that allows him/her to savor the pleasure of a refreshing cup of coffee with no fuss.