Radiation is broken down into many subsets divided by different wavelengths. These wavelengths include ultraviolet, infrared, micro-wave and radio frequency. The wavelength spectrum ranges from 0.72 to 1,000 micron, and the infrared region is divided into three subsets:
- Short-wave (near): 0.72 to 2 micron (7,000 to 2,150oF).
- Medium-wave (middle): 2 to 4 micron (2,150 to 845oF).
- Long-wave (far): 4 to 1000 micron (845 to <32oF).
When infrared energy strikes an object, it causes the surface electrons to excite and oscillate. This oscillation creates heat. The electromagnetic energy travels in straight lines from the source, and it can be directed into specific patterns with the use of properly designed reflectors. It decreases in intensity as it travels outward from its source.
Why use infrared heating? Infrared heating in process applications provides several benefits. It
- Reduces floor space.
- Lowers energy consumption.
- Increases line speed.
- Reduces maintenance.
- Provides a clean operating environment.
For all of its process benefits, some processors are concerned about using infrared heating. They need not be. Most concerns about infrared are based on misconceptions; a properly designed system will provide years of effective heating. Let’s take a closer look at the five most common misconceptions and the facts behind the buzz.