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Heat Pipe Demo

SKU #HP-100
Availability: In Stock
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It is Super Hot and Super Cool!

Description

Hold the end of each piece of copper in each hand and immerse the ends into a container of hot water or ice water. It is amazing how quickly heat transfers in the heat pipe and how slowly it transfers in the solid copper. Heat pipes are used in laptop computers and other devices for cooling. They work on the principle of the heat capacity of water and a wick. Explanation included. 5.5" (13.9 cm) long by 3/16" in diameter (0.4 cm).

Video

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Heat Pipe: a device that transfers heat with great efficiency- as demonstrated by this fantastic kit from @educational_innovations . Here a liquid crystal goes from green (room temp) to black (near freezing) showing the heat transfer to a piece of ice through a heat pipe (top) and a similar sized piece of solid copper rod (bottom). As you can see the heat pipe cools much faster than the copper rod even though copper is an excellent conductor of heat. The heat pipe is a thin shell of copper that surrounds a tube of sponge like material filled with some water vapor and sealed with a low pressure inside. The heat is transferred from one end to the other by the phase transition of water- at the warm end water in the sponge evaporates into vapor absorbing heat energy, the vapor travels down the hollow core to the cold end where it condenses into liquid releasing heat energy. The water is wicked by the sponge to the warm end and the process repeats. Heat pipes like this one pull heat away from the CPUs in modern computers preventing them from melting. The amazing heat transfer ability is clearly felt in the fingertips if one places the copper rod and heat pipe into a glass of ice water-the heat pipe immediately gets cold! Follow the link in my profile for info on where the buy this heat pipe demo and other amazing items featured here on @physicsfun. #physics #physicstoy #physicsfun #thermodynamics #heat #heatpipe #physicsdemo #liquidcrystal #thermometer #heattransfer #conductivity #phase #phasetransition #latentheat #science #scienceexperiment #scienceisawesome

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Lesson Ideas

Download the pdf of this lesson!

A Demonstration of Vapor Pressure and Heat of Vaporization
by Ron Perkins

Immerse the ends of two pieces of metal into a container of hot water. One becomes hot immediately, while the other slowly increases in temperature. The heat pipe also works when the end is immersed in ice water.

Explanation:

The piece of metal, which conducts heat slowly, is a solid piece of copper. The other piece of metal, which conducts heat quickly, is an evacuated hollow piece of copper containing a small amount of liquid water, water vapor, and a wick. This is called a 'heat pipe'.

The heat pipe operates on the difference in vapor pressure due to a difference in temperature of the two ends. The greater the temperature; the greater is the vapor pressure of a liquid. At the end where the heat pipe is immersed into hot water, liquid inside the pipe evaporates until it reaches its vapor pressure. This process of evaporation requires the absorption of heat, called the heat of vaporization. Because the tube has been evacuated of air, this hot vapor travels quickly throughout the tube. At the other end where the tube is cooler, the vapor pressure is less. Consequently the excess vapor condenses, releasing heat. There is a fiber wick inside the tube to distribute the condensing liquid.

Heat pipes are used in laptop computers and other devices for cooling, such as certain types of air conditioners. They are useful for transferring heat quickly from one area to another.

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