Infrared heat technology

Heraeus Noblelight manufactures natural gas or propane fired industrial catalytic heaters that emit infrared heat through a safe, flameless heater technology. By-products are water and carbon dioxide.

Infrared heat transfers energy without contact and generates heat where it is needed. PLC-controlled infrared ovens are precisely adjusted to the thermal process. This improves process stability and quality, increases capacity and saves space, time and energy. Compared to conventional systems, process times can be reduced by up to 65% and the required space by up to 50%.

Heraeus Noblelight is the expert for infrared heating technology.
Vulcan Catalytic™ completes the Heraeus portfolio, covering the complete spectrum from short to long wave infrared.

Gas Catalytic IR - Technology Overview

Heat The Part - Not The Air

Gascatalytic infrared technology

Gas catalytic infrared emitters convert both natural or propane gas into infrared energy using a specialized platinum catalyst.
By-products are water and carbon dioxide.

Gas Catalytic IR Panel Construction

gascatalytical IR panel construction

Characteristics

  • Surface temperatures 175°C to 480°C
  • Maximal covering power about 20 kW/m²
  • Flameless reaction
  • Even heat distribution
  • Intelligent control
  • Emission of CO2 and H2O

Gas Catalytic Infrared Distribution

energy distribution gascatalytic IR

Energy in the form of infrared is emitted in a 180° spherical axis across the entire face of the heater.
When paired on opposite walls of an oven, this pattern provides complete coverage across the part window and allows for a diffused heat that is easily controlled.

Gas Catalytic Infrared Heat: Long to Medium Wave Infrared Energy

gascatalytic IR wavelengths

The wavelength of gas catalytic infrared varies with output power percentages.
For example; maintaining lower temperatures requires less gas and produces longer wavelengths, allowing for extended dwell and slower reaction times, without over heating.
With higher outputs, infrared wavelengths become more dense, creating a medium wave emission. This requires a slightly higher percentage of gas output and is suited more toward rapid response needs such as pre-heat, gel or drying applications.
The output percentages are regulated by an intuitive Gas Pulse System. This recipe capable, HMI and PLC provide the GPS information that controls temperature through a series of LOW and HIGH gas pulses, regulating the platinum reaction.

Why Hotter Is Not Better

  • The natural absorbance wavelength for organic substances – water, epoxy, polyester, ABS, acrylic – is 3-4 microns
  • The maximum energy output from a Heraeus – Vulcan Catalytic Heater matches these absorbance wavelengths
  • Net result is a diffused “Soft Heat” as opposed to higher temperature heat sources that emit a wavelength that is shorter, more intense with more convection – inefficient heat source
  • Quickest method to heat “heat sensitive” materials without burning the coating is to match absorbance with emittance

Benefits of Gas Catalytic IR and the 3:1 Rule

What is the 3:1 Rule?

  • For every three minutes it takes to cure a part in a conventional convection oven, it will require only one minute in a Gas Catalytic IR oven

What Does This Mean?

  • For example, parts that normally take 30 minutes to cure conventionally, only take 10 minutes in a Gas Catalytic IR oven

Practical Implications

  • Thermal Process Ovens are shorter and quicker than convection ovens
  • ​The use of Gas Catalytic IR ovens reduce energy bills

​Why is the 3:1 Rule so Important?

  • ​The rule fundamentally demonstrates that less energy is required during process heating​​

Gas Catalytic IR Oven Design

Gascatalytic infrared system

Infrared powder coating ovens from Vulcan Catalytic® Systems are custom designed specifically for the intended application. The main aim is it to optimize the coverage of the part with infrared, thus ensuring reduced curing times. This is achieved by selecting the correct arrangement of heaters and maximizing using fully reflected IR technology for complete cure ovens.

Ovens are designed with SolidWorks design programs ensuring a high degree of “fit and finish”, allowing all parties to thoroughly view the oven design and ensure exact placement on the paint line. When working with distributors, we can provide a package which includes the oven, fully designed in Solidworks, heaters and controls. This enables local manufacture of the sheet metal components for the oven, allowing quick and easy assembly of the powder coating oven system close to the end user, wherever they are in the world.

Fully reflected IR technology is designed into the oven, ensuring the most efficient absorption of infrared by the part or coating. Multi faceted, reflective oven interior focuses the IR energy onto the part. The removable outside panels are non insulated but remain cool to the touch.

Vulcan Catalytic® powder coating oven systems and heaters are pre plumbed and wired prior to leaving the plant, ensuring rapid installation at the customer’s plant. Exterior of the ovens are powder coated to customer’s colors and are easily removable for inspection.

Multi zone gas pulse technology is used throughout the oven design concept, allowing for front to back and top to bottom temperature control. Control of the zones is via an intuitive PLC operator interface that is also the diagnostic center. The control system is ideal for heating heat sensitive substrates such as MDF as well as traditional metal parts.

Gas Catalytic Infrared Oven Control

The Inefficiencies of Convection Powder Coating Ovens

control screen

The importance of powder coating oven system control can assessed by considering a medium sized gas fired convection powder coating oven. A typical system will probably have gas burner capacity totaling approximately 1500 kW. There will be very little control with this type of system, except to maintain an air temperature within the oven. The burners are either on at full output or off. No account is made of the part size or batch size. Because it can take up to an hour for a convection to come up to temperature, operators will keep the oven on for a full shift. This will include work breaks and with no regard to the work load for that shift. Such a typical system will produce a Carbon output of 1 tonne in a ten hour period.

The Department of Trade in the UK have analysed a series of standard plant and their figures show that gas fired convection ovens are generally less than 7% efficient. Even worse, industries which process light sheet-metal, the efficiency may drop to 5% or less. Where does the remaining 95% of the burner power go? It is lost in exhaust gasses, leakage from silhouettes, through the oven walls and explosion panels and in heating the conveyor or track. The oven continues to work hard even when it is completely empty.

Add in the fact that conventional ovens take about an hour to come up to operating temperature, and cannot be turned off until the end of a shift. This means that the oven will be running at full power during breaks in production and worker break times. Overall, there is very little powder coating oven system control that can be applied. This is expensive and wasteful of energy.

Powder Coating Oven System Control with Gas Pulse Technology

A Gas Catalytic Infrared Powder Coating Oven can be very carefully controlled by creating a programmed and repeatable heat profile throughout the oven which is easily customized to the parts, our powder coating oven control system reduces the total amount of heat that is output by the system. We do this by creating zones within the oven that can be individually controlled via the PLC control panel. The heat output of each individual zone is controlled to suit the parts going through the oven.

The physical control of the gas flow to the heaters is achieved using Gas Pulse technology which gives a high degree of temperature control. At Low Fire (0%) the average surface temperature of the heater is 300-350°F. (149-177°C.), while at High Fire (100%), the average temperature is 850-900°F. (454-482°C.) depending on heater orientation and position in an oven.

In practical terms, powder coating oven system control in gas catalytic infrared ovens means that gas usage can be reduced by up to 50%, hence reduced energy bills.

Get in contact with our infrared experts