“Noblelight News: Application Notes for IR Heating” offers concise information about infrared and ultraviolet solutions. The monthly free electronic newsletter from Duluth, Ga.-based Heraeus Nobelight focuses on applications and success stories as well as technical concepts. A recent issue looked at convection vs. infrared technologies in a Q&A format. Some sample questions include:

Q: How is heat transfer different?
A: Convection can only be controlled by air temperature and air speed. With infrared emitters, flexibility in heatup rates and temperatures can be achieved using different energy densities and wavelengths.

Q: How energy efficient are the technologies?
A: Convection can waste a lot of energy when switching from large to small components. Infrared emitters can target energy to the areas that require heating. Zoning allows users to turn on or off heaters as needed.

Q: What about maintenance costs?
A: All process heating systems require some maintenance. Convection requires regular maintenance of components such as fans, filters, pipes, seals and burners. Full maintenance may require a complete strip down of the oven. Electric infrared systems require regular maintenance such as changing emitters or filters -- typically less than convection systems.

Q: How do you control temperature with changing parameters?
A: For convection ovens, it can take a long time to reduce or raise the air temperature to suit changing line conditions. Infrared emitters can be regulated instantly to changing conditions. Closed-loop control via speed or temperature is possible.

Q: How is the flexibility with mixed batches?
A: In a convection oven, although components may heat up at different rates, they never exceed the temperature of the convection oven. In an infrared system, infrared also heats up components at different rates and will reach different temperatures depending on component mass. It is possible to overheat a component using infrared. Care should be taken to group parts of similar size and mass.

For more information on this topic or to see others that have been covered, check out the newsletters available at www.noblelight.net/newsletter or send an email to subscribe@noblelight.net.

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