When the object to be heated is heated from a distance, diffuse reflection ray is only emitted to the surroundings.
When the condenser mirror of sufficient size is brought close to the object to be heated and vertically heated, the diffuse reflection ray is returned to the condenser mirror and reheated as a heat source.
Therefore, when tilted and heated, ray energy is reflected and emitted without recursion.
Verification of rereflection heating method-difference in irradiation angle
Comparison of Simple Condense Heating and Re-Reflective Heating
Taking the HPH-60 equipped with a Φ60 condense mirror as an example,
At a focal length of 30 mm (f30), diffuse reflection light is reused, so the temperature is raised to 1300℃ in 10 seconds,
At a focal length of 60 mm (f60) and a focal length of 105 mm (f105), the temperature is less than half because diffuse reflections are not reused.
The difference between 60 mm (f60) and 105 mm (f105) without re-reflecting heating light is small.
When the condenser mirror of sufficient size is brought close to the object to be heated and heated, it becomes high temperature due to re-reflection heating.
Related page:
6-1.About Re-reflective Heating Method 
6-3.Re-reflective heating method – Groove heating 
6-5.Re-reflective heating method – Dome heating 
6-4.Re-reflective heating method – Frame heating 
6-6.Re-reflective heating method – Box heating 
5-3.Efficient method of Infrared ray drying 
3-8.Wide Range of Plane Heating with Line Heating Type Halogen Line Heater 
2-4.Focal Length and Focal Diameter of Halogen Point Heater