Energy savings in powder coating lines
The oven with infrared emitters as a solution?
The current economic situation will impact us in the medium and long term. What are the technical solutions to cope with a very unfavourable and uncertain energy market? What kind of technological solutions can we consider? The solution: the hybrid oven with infrared emitters.
The process of curing powder coating
The curing of powder coatings requires a lot of energy since parts need to be heated up to 150°C or even 200°C. The dwell time for complete curing can vary from 5 to 20 minutes depending on the thickness and mass of the part.
The energy needed to heat up a part is a physical value (not depending on the technology or process in use). The energy transfer determines the heating rate and therefore the process time. The process time and the speed of the line determine the length of the oven. It is this heat-up stage that must be managed in order to control energy consumption.
The key to reducing energy consumption lies in this energy transfer: energy transfer by infrared radiation is much more efficient than energy transfer by convection with hot air. The infrared emitter radiates/transfers energy directly to the product without having to heat any air.
The integration of the infrared emitters at the inlet of the conventional convection oven therefore allows for a more efficient heating and thus a reduction of consumption. The sole function of the convection oven is to maintain the temperature during the curing/polymerisation process. We therefore introduce the hybrid oven with infrared booster.
The key to reducing energy consumption lies in the energy transfer
If we compare the two oven concepts in their efficiency in the heat-up, the conventional convective oven and the IR booster integrating infrared emitters, we obtain the following results:
Automotive part (bar) : Steel, 3.6 kg, Diameter 4 cm, 180°C
- Convection oven: 50 minutes
- IR booster: 5 minutes
Automotive shock absorber: Steel, 1.1 kg, 150°C
- Convection oven: 60 minutes
- IR booster: 2.5 minutes
Metal plate: Steel, 1.5 mm, 160°C
- Convective oven: 7.5 minutes
- IR booster: 1.5 minutes
Bike frame: Aluminium, 2,6 kg, 160°C
- Convection oven: 4 minutes and 30 seconds
- IR booster: 90 seconds
50% to 60% of the energy generated by the infrared emitter is transferred directly to the product and raises its temperature. For convective energy, only 5% reaches the product. This results in a higher efficiency of the hybrid oven with infrared booster both for the heating up and for the following maintaining during curing.
A better overall thermal efficiency is reached by integrating infrared emitters for the heating up and the using the convection section for the curing. The integration of an infrared booster at the entrance of convection ovens will:
speed up gellification of the powder,
- improve surface tension of the coating film,
- eliminate pollution of parts or environment,
- reduce the length of the oven,
- improve productivity,
- reduce energy consumption.
Eratec infared emitters
Eratec infrared emitters are efficient gas burners with an emitter head equipped with a metal fiber structure. The size, shape and power output range of the emitter are adapted to the exact needs of your process. The emitters heat up and cool down within seconds. The power output of the infrared emitters is continuously modulated. They are easily adapted to the constraints of powder coating curing ovens. The high durability and the very low level of maintenance required contribute to the performance and reliability of your equipment. The flexibility of power modulation results in user friendly operation and last but not least: significant energy saving.