1. Through air drying assisted by infrared radiation: the influence of radiator power on drying rates and temperature
- Author
-
Lennart Nilsson, Aron Tysén, and Hannes Vomhoff
- Subjects
0106 biological sciences ,Materials science ,Infrared ,Lab scale ,Forestry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Power (physics) ,law.invention ,law ,010608 biotechnology ,Scientific method ,Thermography ,General Materials Science ,Air drying ,Composite material ,0210 nano-technology ,Radiator - Abstract
The use of infrared radiation for heating the web in the through air drying process was investigated in lab scale. The hypothesis was that infrared radiation should be a more efficient method to transfer drying energy to the wet web compared to hot air, but that a certain air flow is still required as a transport medium for the evaporated water. A trial program comprising handsheets made of two types of bleached chemical pulps, five grammages (15, 22, 30 and 60 g/m²), and dried with five radiator power levels was performed on a lab scale through air drying equipment. Drying times of the samples were determined from temperature data recorded with an infrared camera. The use of infrared radiation shortened drying times, especially for low grammage samples. The shortening of the drying time ranged between 10 and 45 %. The most substantial shortenings were obtained for the lowest grammages and the highest radiator power level. However, the increase of power did not linearly shorten drying time. After an initial shortening at the lowest power level, the positive effect of the IR heating decreased as the power was further increased.
- Published
- 2018