BLOW DRYERS

 

Sarah Khan

Technical Description

Course: Writing for Engineers

Professor: Troy Hill

Type: Final Draft

Year: Spring 2019

INTRODUCTION:

A blow dryer, (hairdryer, hair dryer) is a device designed to blow normal or hot air over damp hair, in order to accelerate the evaporation of water particles and dry the hair (Srinivas Boddula, 2018). This handheld, electromechanical device was invented by French hairstylist Alexandre-Ferdinand Godefroy in 1888, as stated in a New York Times Magazine article “Who Made That Hair Dryer?” (Jessica Gross, 2013). Figure 1 illustrates an older model of a blow dryer, obviously very different than today’s blow dryers.

Figure 1: This metallic blow dryer was used in the 1930s. Made from metal, they tended to be immensely heavy, and they have wonky electrical connections and use in bathrooms sparked a number of deaths. (Keystone-France, 2018)

Blow dryers are used by many people and have a variety of uses. For example, people, mainly women but also men, use blow dryers to speed up the drying process of their hair, and create different hairstyles. However, blow dryers can be used to dry anything really, not just hair. For example, a blow dryer could be used to quickly dry spilled water on clothing, or even to dry pets, like dogs, after bathing. Just as technology keeps on changing as time goes on, blow dryers too have evolved over time with newer, more innovative, user friendly models still being created today.

 

Figure 2: This image illustrates the different parts that make up a blow dryer. (How do Hair Dryers Work, 2017)

 

PARTS OF A BLOW DRYER:

The main components that make up a blow dryer are shown in Figure 2, above. These main parts are:

1. Housing: This is the shell around all of the blow dryer parts that keeps everything in place.
2. Chord: This is the wire that connects the blow dryer to an outlet or source of electricity.
3. On/Off switch: This is the mechanism that one uses to turn on/off the blow dryer.
4. Heat switch: This is the mechanism that one uses to adjust the temperature of the airflow.
5. Fan Speed Switch: This is the mechanism that one uses to adjust the amount/intensity of airflow.
6. Nozzle: This is found at the very end of the blow dryer, where the air comes out.
7. Fan: This is an apparatus with rotating blades that creates a current of air for cooling or ventilation (Oxford Dictionaries).
8. Motor: This is a machine, especially one powered by electricity or internal combustion, that supplies motive power for a vehicle or for another device with moving parts (Oxford Dictionaries).
9. Heating elements: These are made out of nichrome wire, which is a resistor. A resistor resists the flow of electric energy, turning it into heat energy. (How does a Hair Dryer Work?).

HOW BLOW DRYERS WORK:

         Blow dryers use an electric fan to blow air across a heating coil; as the air passes through the dryer, it heats up (How Products Are Made). All a blow dryer really needs is a motor driven fan and a heating element, as shown in Figure 2, found on page 2. The heating element in most hair dryers is a bare, coiled nichrome wire that’s wrapped around insulating mica boards. Hot infrared waves that blow out of the blow dryer work by increasing the temperature of the air that surrounds wet hair. The basic process is as follows:

1. When you plug in the blow dryer and turn the switch to “on,” air current flows through the hair dryer.
2. The circuit first supplies power to the heating element. In most blow dryers, this is a bare, coiled wire.
3. The current then makes the small electric motor spin, which turns the fan.
4. The airflow generated by the fan is directed down the barrel of the blow dryer, over and through the heating element.
5. As the air flows over and through the heated element, the generated heat warms the air.
6. The hot air streams out the end of the barrel, through the nozzle. (Toothman & Meeker-O’Connell, 2000).

 

CONCLUSION:

         All in all, blow dryers work due to the system of parts that make them up. The fan creates airflow and the shape of the blow dryer directs the airflow towards the nozzle of the blow dryer. Before the airflow reaches the nozzle, it has to pass through the heating elements, thus blowing out hot air. How hot the air coming out of the dryer can get depends on the power supplied to the heating element, and the time the air spends in the barrel of the dryer being heated by the nichrome wire. The higher the wattage, the more heat is generated by the heating element and transferred to the air. Most hair dryers limit this to approximately one-half second to prevent the air temperature from getting too high. (Jessika Toothman & Ann Meeker-O’Connell, 2000).

Works cited

1. (2017, September 24). How do Hair Dryers Work? The Working Parts of a Hair Dryer.

Retrieved from http://artist-commune.com/how-do-hair-dryers-work-the-working-parts-of-a-hair-dryer/

Boddula, S. (2018, November 22). How does a Hair Dryer Work? Retrieved from

https://www.butterflyfields.com/resources/how-does-a-hair-dryer-work/

Fan | Definition of fan in English by Oxford Dictionaries. (n.d.). Retrieved from

https://en.oxforddictionaries.com/definition/fan

Hair Dryer. (n.d.). Retrieved from http://www.madehow.com/Volume-7/Hair-Dryer.html

 

Hofmeister, J. (2019, March 25). 23 Best Professional Blow Dryers for Perfect Hair.

Retrieved from https://heavy.com/beauty/2018/11/best-professional-blow-dryers/

Keystone-France. (2018, January 10). Vintage hair dryer. Retrieved from

https://www.abc.net.au/news/2018-01-11/vintage-hair-dryer/9318410

Meeker-O’Connell, A. & Toothman, J. (2000, December 15). How Hair Dryers Work.

Retrieved from https://home.howstuffworks.com/hair-dryer2.htm

Motor | Definition of motor in English by Oxford Dictionaries. (n.d.). Retrieved from

https://en.oxforddictionaries.com/definition/motor