Heat Transfer (Conduction, Convection, Radiation)

Thermal energy moves from warmer regions to cooler ones through conduction, convection, and radiation. Objects continuously lose heat until they achieve thermal equilibrium, meaning they reach the same temperature as their environment. For instance, a steaming mug of tea will gradually cool until it matches the temperature of the room.

But how that mug looses that heat is what this blog is all about.

CONDUCTION:

Thermal energy moves through solids mainly via conduction. This phenomenon happens when two solid items with varying temperatures come into contact, enabling heat to transfer from the warmer object to the cooler one. For instance, in the scenario of a hot coffee mug resting on a cold table, the thermal energy shifts from the mug to the table beneath it.

CONVECTION:

Convection refers to the movement of fluids, whether they are liquids or gases, and can occur naturally or be induced by external forces. Fluids can either absorb or release heat, depending on their temperature. Natural convection happens due to variations in density; for instance, steam rises from the top of the mug as the steam rises, colder air is cycled in.

RADIATION:

While the coffee emits infrared radiation as it loses heat, this process is generally less significant compared to conduction and convection in the context of a cup of coffee. This type of heat loss can be felt by holding your hand near a warm coffee cup as shown.

No matter how the heat is transferred to an object, if it needs to be cooled there is a good chance that one of our Application Engineers has approached a similar issue and can help. To discuss, contact us, and we will walk through the best method to eliminate the heat from within your application.

Jordan Shouse
Application Engineer

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It’s Getting Hot In Here!

Okay, if you did not finish the song lyrics when reading the title, it’s okay, we can still be friends. In all actuality, the temps are warming up here in the MidWest as we prepare for our false Spring as indicated by the freezing temps and snow we received earlier this week. There is one thing that has stayed constant and that is the methods of heat generation.

1 – Kettle-convection-conduction-radiation

Heat generation is a result of energy conversion. The conversion of energy to do work, whether it is actual voltage going through a transformer that operates a neon sign to light up the roadside sky or energy from a hydraulic ram that is compacting recycled paper into a bundle and the hydraulic fluid is being pressed in and out of cylinders from a pump, all of it will have some form of a heat byproduct. This heat then gets transferred and how it is transferred can be helpful to know.

2 – Energy Transfer – Heat

At the molecular level, atoms store the energy that will cause electrons to enter into an excited state and rapidly switch between shells. When the electron returns to a lower shell (closer to the nucleus), energy is released; the energy released is then absorbed by atoms at a lower energy state and will continue until the thermal energy is equal between the two objects. Heat has four fundamental modes of transferring energy from surface to surface, and they are as follows:

Advection
Advection is the physical transport of fluid from point A to point B, which includes all internal thermal energy stored inside. Advection can be seen as one of the simpler ways of heat transfer.

Radiation
Radiation is the transfer of thermal energy through empty space and does require a material between the two objects. Going back to how thermal energy is released from atoms when the electron returns to a lower energy shell, the energy is released in the form of light ranging from infrared light to UV light. Energy in the form of light can then be absorbed by an object in the form of heat. Everyone experiences radiation transfer every day when you walk outside; the light from the sun’s radiation is what keeps this planet habitable.

Conduction
Conduction can also be referred to as diffusion and is the transfer of energy between two objects that have made physical contact. When the two objects come into contact with each other, thermal energy will flow from the object at the higher temp to the object at the lower temp. A good example of this is placing ice in a glass of water. The temperature is much lower than the room temperature. Therefore, thermal energy will flow from the water to the ice.

Convection
Convection is the thermal energy transfer between an object and a fluid in motion. The faster the fluid moves, the faster heat is transferred. This relies on the specific heat property of a molecule to determine the rate at which heat will be transferred. When a molecule has a lower specific heat, it takes faster motion and larger volumes to achieve the full effect of convection transfer. Convection is used in modern ovens to get a more even heat throughout the food while cooking.

No matter how the heat is transferred to an object, if it needs to be cooled there is a good chance that one of our Application Engineers has approached a similar issue and can help. To discuss, contact us, and we will walk through the best method to eliminate the heat you need to.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – “Kettle-convection-conduction-radiation” by P.wormer is licensed under CC SA 3.0
2– “Energy Transfer – Heat” by Siyavula Education is licensed under CC BY 2.0

Fundamental Modes of Heat Transfer

Generally I like to write about cool stuff. Whether it is a new product like our TurboBlast Safety Air Gun, an application that really helped cool down a process for a customer, or even something cool I have done like a GORUCK event or training. Well, today is not one of those days, today we are going to talk about the opposite of cool … HEAT and more importantly the methods it is transferred.

1 – Energy Transfer – Heat

The process of how heat is generated all starts with a conversion of energy. Whether it is friction, or converting energy to light, or even converting energy to a different voltage through something like a transformer. No matter how it is generated, heat will begin to transfer. On the molecular level, atoms are storing the energy which will cause electrons to enter into an excited state and rapidly switch between shells. When the electron returns back to a lower shell (closer to the nucleus) energy is released; the energy released is then absorbed by atoms at a lower energy state and will continue until the thermal energy is equal between the two objects. Heat has four fundamental modes of transferring energy from surface to surface and they are as follows:

Conduction
Conduction can also be referred to as diffusion and is the transfer of energy between two objects that have made physical contact. When the two objects come into contact with each other thermal energy will flow from the object with the higher temp to the object with the lower temp. A good example of this is placing ice in a glass of water. The temperature is much lower than the room temperature therefore the thermal energy will flow from the water to the ice.

Radiation
Radiation is the transfer of thermal energy through empty space and does require a material between the two objects. Going back to the how thermal energy is released from atoms; when the electron returns to a lower energy shell the energy is released in the form of light ranging from infrared light to UV light. Energy in the form of light can then be absorbed by an object in the form of heat. Everyone experiences radiation transfer every day when you walk outside; the light from the sun’s radiation is what keeps this planet habitable.

Convection
Convection is the transfer of thermal energy between an object and a fluid in motion. The faster the fluid moves the faster heat is transferred. This relies on the specific heat property of a molecule in order to determine the rate at which heat will be transferred. The low the specific heat of a molecule the faster and more volume of the fluid will need to move in order to get full affect of convection. Convection is used in modern ovens in order to get a more even heat through out the food while cooking.

Advection
Advection is the physical transport of a fluid from point A to point B, which includes all internal thermal energy stored inside. Advection can be seen as one of the simpler ways of heat transfer.

No matter how the heat is transferred to an object, if it needs to be cooled there is a good chance that one of our Application Engineers has approached a similar issue and can help. To discuss, contact us and we will walk through the best method to eliminate the heat you need to.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – “Energy Transfer – Heat” by Siyavula Education is licensed under CC BY 2.0

Industrial Housekeeping Overview: The Vac-u-Guns

Manufacturing product can be a very dirty process that can generate large amounts of biproduct, trash, and loose material that is lying around or has been spilled. Especially when it comes to spilled material you might not want get rid of the material because it is still good. Well, EXAIR has the solution for you! Introducing the Vac-U-Gun systems! The Vac-U-Gun system is just as it sounds; a hand-held vacuum cleaner that can be turned on and off by simply pulling back the trigger. This system can allow one to easily clean up messes such as metal chips, plastic pellets, nuts, bolts, paper scraps, and much more. Altogether this gives you and easy way to keep your work space clean. Best of all the Vac-U-Gun isn’t just a vacuum system it can also work as a blower to blow air or transfer material.

EXAIR’s Vac-U-Gun System

The Vac-U-Gun system works off of the same principle of Entrainment as EXAIR’s Air Amplifiers and Line Vacs which can produce a strong suction for moving material. The removable generator located in the back of the Vac-U-Gun can be easily taken out and reoriented in order to create a strong blowing force that can be used for either blowing surfaces off or transferring material.

Vac-U-Gun Kits

The Vac-U-Gun can be purchased in three different kits to help get you started:

6192 – Collection System: Vac-U-gun, reusable bag, brush, crevice tool, skimmer tool, (2) extension wands

6292 – Transfer System: Vac-U-gun, 10’ Vacuum hose, brush, crevice tool, skimmer tool, (2) extension wands

6392 – All Purpose System: Vac-U-gun, 10’ Vacuum hose, reusable bag, brush, crevice tool, skimmer tool, (2) extension wands

If you have a blind hole that you just can’t seem to be able to clean out, then look no farther than the Deep Hole Vac-U-Gun. The Deep Hole Vac-U-Gun has all the same features as the Vac-U-Gun but adds a quick blast of air to dislodge anything in the holes so it can be vacuumed up.

The air flow of EXAIR’s Deep Hole Vac-U-Gun

Currently until May 31, 2021 then take full advantage of our promo which adds a free Vac-U-Gun to the purchase of our Industrial Vacuums. Now who doesn’t like free stuff? See the link in the image below to see our promotion page. Of course, they can also be purchased separately.

Industrial Housekeeping Promo

If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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