INDEX
Outline of Re-reflective heating method
Focused heating using a halogen lamp is a heating method that focuses ray on the object to be heated.
Thermal energy that is not absorbed by the object to be heated is reflected ray and dissipated into the atmosphere.
Re-reflecting heating method is a method to use the reflective material to reuse the reflected ray that was being dissipated wastefully, and to heat it uniformly at high temperature.
Highly reflective material
Materials with high reflectivity and low infrared absorptivity reflect infrared rays and diffuse heat energy and can not reach high temperatures.
Diffused thermal energy can be recycled to high temperatures using reflectors.
Minimal material
Materials with small infrared receiving area remained low in heating efficiency.
The heat energy that has been transmitted or diffused can be side-heated using the reflective material to expand the ray receiving area to a high temperature.
Uniform heating
Heating using a halogen lamp was a difficult process, as the shape of the heat source was projected onto the object to be heated because the heat source was a point or a line.
By out-focusing to disperse the irradiation ray, and reusing the diffused heat energy using the reflector, the heating part is dispersed, so the temperature variation is reduced.
Material of reflector
Gold-plated mirror
The high reflectivity mirror plane using gold plating for high temperature is the best material.
We can divert our condense mirror.
If steam or oil smoke is generated from the object to be heated, it is difficult to maintain the mirror plane.
Aluminium polishing mirror
Inexpensive Aluminium polishing mirrors are site-friendly materials that can be used daily in clean rooms and cleaning operations.
As the melting temperature of Aluminium is about 640℃, forced cooling is required.
We can divert our condense mirror.
Stainless steel polishing mirror
Stainless steel plates are not suitable as reflectors to which halogen ray is directly emitted.
Stainless steel polishing mirror is difficult to maintain its mirror plane in high temperature environment because oxide film such as Cr2O3 · Fe3O4 is formed as a protective film, which is called high temperature corrosion.
And when returning from high temperature to normal temperature, the phenomenon that the film exfoliates from the base material due to the difference of the thermal contraction rate, the film breakage occurs.
The exfoliated oxide film is a source of dust.
Ceramic material
It is effective to grind the refractory bricks to reduce plane irregularities.
Ceramic-based white diffuse reflective planes (such as silica board) are close to maintenance-free because they maintain high reflectance by self-cleaning when they become hot due to thermal insulation.
Also, even if it is not a smooth reflective plane, as long as it has good insulation performance, no material is chosen. (It is the same as high reflectivity because it is re-radiated from the wall as the temperature rises).
Related page:
6-6.Re-reflective heating method – Box heating 
6-5.Re-reflective heating method – Dome heating 
6-3.Re-reflective heating method – Groove heating 
6-4.Re-reflective heating method – Frame heating 
6-2.Re-reflective heating method – Large condense mirror 
5-4.Proper use of near-infrared heating and far-infrared heating 
3-1.Overview of Halogen Line Heaters 
3-8.Wide Range of Plane Heating with Line Heating Type Halogen Line Heater