## 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.

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 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 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

## 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.

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.

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.

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.

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
Visit us on the Web

## Getting A Little More Vacuum and Flow

Last week, a customer called and indicated that he was a long time user of the model 6013 High Velocity Air Jet.

The customer was using the Air Jet to remove light trim scrap from a manufacturing process. The Air Jets utilize the Coanda effect (wall attachment of a high velocity fluid) to produce air motion in their surroundings.  A small amount of compressed air to the Air Jet is throttled through an internal ring nozzle at speeds above sonic velocity.  In the above image, this produces a vacuum at the left side, pulling in large volumes of surrounding air. By utilizing this vacuum pull and ducting the right side exhaust, air and scrap stream to a collection area. The customer assembled a small, efficient, and inexpensive scrap removal system.

The reason the customer had called in was there were some recent changes to the manufacturing process and needed a bit more vacuum force and flow to handle larger scrap and longer travel. We explored using a larger shim, but they were already using the largest size (0.015″.) We talked about the other products that EXAIR offers (Air Amplifiers, Line Vacs) that are used for scrap removal and conveyance.  But with any change, there are usually other modifications and approvals that must be dealt with in order to proceed. So we hit upon the Adjustable Air Jet, which is an adjustable version of the model 6013.

The model 6019 Adjustable Air Jet utilizes an adjustable air gap in place of the fixed shim thickness.  This allows for greater air flow, which results in greater vacuum and conveyance distances. As is the case for many customers, we gathered some additional data to help this customer make a decision. We set up each of the units and tested them at maximum capabilities, and the model 6019 was shown to deliver upwards of 50% greater flow.  The customer felt certain this level of performance would handle what the changed process would require, and best of all, no modifications to any part of the set-up would be required, simply install the 6019 where the 6013 was currently placed.

The High Velocity Air Jet is also part of the model 1909 Blowoff Kit, and is also used in the model 8193 Ion Air Gun and model 8194 Ion Air Jet, for Static Elimination applications. Of course, each can be purchased as an individual item.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
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## Super Air Knife Used For Product Sorting

We recently announced the launch of the new 1126 1” Flat Super Air Nozzle, a marvel of its kind – compact, fully laminar, adjustable, and quiet.

Another laminar airflow product we manufacture is nothing new.  The Super Air Knife has been tried and tested for decades with new applications coming to light every day.  For example, in the sketch below we worked to integrate an EXAIR Super Air Knife (Aluminum) into a conveyor application in order to laterally move a low weight item from one belt to another.

The air knife solution provides a vital function for multiple conditions in this application.  It allows for product movement in a fully lateral plane with little to no product disorientation in the event of a defect, or an overage on the main conveyor line.  Rejected items and workflow backup were causing unnecessary costs for this producer, and we were pleased to offer a solution.

When coupled with a PLC (similar to the EXAIR EFC – Electronic Flow Controller), the application was integrated with a time delay so that maximum energy efficiency was achieved.  No compressed air was wasted, and instantaneous blow off force didn’t have to be sacrificed.

This is an excellent example of how a disciplined and educated approach benefited an application.  If you know of an application with which EXAIR may be able to help, give us a call, email, or tweet.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE