Shortwave Infrared Lamps for Industrial Infrared Heating
SWIR lamps utilize a low quality tungsten filament to provide a high temperature source that responds quickly to voltage changes for precise control in your industrial infrared heating process. These quartz infrared lamps are sealed and filled with an inert halogen gas, which helps extend the life of the filament. Shortwave IR emitters feature a white ceramic or gold reflector coating on the back of the lamp to make it unidirectional. Glare-free, ruby red, Helen-coated, and satin-coated quartz lamps are available to filter out most high-intensity visible light.
The sealing area at both ends of the shortwave lamp consists of a flat molybdenum ribbon welded to the tungsten filament and lamp holder leads or other terminations and clamped to be airtight. Several ceramic and metal bottom covers are available:
The end seal area must be kept below 350°C (662 F) to prevent lamp failure. To prolong lamp life due to the high temperature of the filament (up to 2400° – 4350° F), it is advised to isolate the seal area and/or provide an air stream to cool the area. The lamp leads can be bare nickel wire, fiberglass insulated or PTFE high temperature insulated.
To learn more about Shortwave IR Lamps, please get in touch with us. We would love to utilize our decades of experience in industrial infrared heating to help you find the right infrared heating solution for your process.
Specifications for Shortwave IR Lamps
|Specifications for Shortwave IR Emitters|
|Lamp Temperature||2400°C (4350°F) ; Peak wavelength 1.15 microns|
|Diameter||T3 10mm (3/8”) ; T4 12.5mm (1/2”)|
|Maximum Heated Length||T3 1475mm (58”) ; T4 1830mm (72”)|
|Watt Density||100-200 Watts per inch|
|Voltage||120V – 600V|
|Controls||“Soft start” SCR with Pyrometer, IR Thermometer (IRT), or Manual.|
|Mounting||Horizontal or Vertical|
|Zoning||Multiple emitters can be easily wired in multiple zones|
|Heat Up/Cool Down||1 second|
|Orientation||Face Up, Face Down or Vertical|
|Colored Quartz||Optional Ruby Red (Non-glare) or Satin|
|Reflective Coating||Gold (Makes heaters unidirectional and wavelength pure) or Ceramic (more rugged than Gold and nearly as efficient)|
Features of Shortwave Infrared Heating Lamps
1. Quick Response
Infrared lamps heat up and cool down instantly with changes in applied voltage. They radiate 90% of the available radiant energy in less than a second of switching on. In contrast, long wavelength infrared lamps need to be turned on for several minutes to achieve the same relative output. Likewise, the short-wave infrared emitter of the lamp cools faster than the long-wave infrared lamps. This is partly due to the higher thermal mass of the long wavelength emitters.
2. Tungsten Filament
High-density infrared energy is produced by a tungsten filament in the lamp. The filament is supported by a tungsten filament ring anchor, tantalum disk, or filament deflection winding to form the support from the filament itself. The bracket prevents the filament from contacting the quartz lamp housing and causing lamp failure.
The inert atmosphere in the quartz glass envelope protects the tungsten wire filament from oxidation.
All T3 lights are 3/8″ in diameter, while T4 lights are ½” in diameter. These lamps are available in various lengths and wattages, and with clear or translucent quartz glass tops. Translucent lamps are used to reduce glare requirements. Before applying voltage to the lamp, the exterior of the quartz glass envelope must be cleaned. Any residue or salt deposits (sweat) on the housing can absorb energy or react with the quartz and cause the lamp to fail prematurely.
5. Optional Coating
The application of special coatings on the housing improves radiation of the desired wavelengths and increases energy efficiency. The black coating (efficient far-infrared radiation) allows the lamp to radiate almost 100% of the energy in the visible spectrum, or convert 70-80% of the energy from the near-infrared region to the infrared region. Infrared. This far infrared output is two to three times that of conventional halogen heaters. A white reflective coating (the strongest radiation in a fixed direction) applied to half of the lampshade will efficiently radiate energy in a specific direction. This type of coating eliminates the need for mirrors and other optics, making it a cost-effective and space-saving alternative.
6. Electrical Connections
In most cases, the connection to power the tungsten filament is made through a flexible coiled cable. Some lights also use button contacts and screw bases for this connection. Lamps with terminal leads should be installed with a small amount of slack in the leads to allow for thermal expansion during operation. This would eliminate lamp failure caused by rigid wires transmitting this expansion to the quartz glass cover.
7. End Seals
Standard end seals are limited to approximately 350°C (662°F). Running lights above this level can cause oxidation, overheating, and eventual burnout. Some heaters provide cooling of the lamp end seals to increase the time and temperature they can operate and prolong lamp life. End seals are available in metal and ceramic versions. Metal end seals have non-insulated leads, while ceramic end seals have insulated leads. Ceramic end seals are used to protect the connection of each lamp lead to the lamp emitter filament, and the insulated leads are electrically isolated.
8. Lamp Orientation
Some lamps are designed to work in a horizontal position so that the filament is equally supported along its length. Shorter lights can be run in a vertical position because the filament doesn’t sag and stretches on its upper part due to its weight. Special vertical burner lamps available in longer lengths have grooves in the quartz housing to hold individual filament spacers and prevent the filament from sagging when operating vertically.