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The Influence of Wood Moisture Content on the Processes of Freezing and Heating
- Source :
- Applied Sciences; Volume 11; Issue 13; Pages: 6099, Applied Sciences, Vol 11, Iss 6099, p 6099 (2021)
- Publication Year :
- 2021
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2021.
-
Abstract
- In wood processing, wood is exposed to an environmental temperature of less than 0 °C for some time, which mainly occurs during the air drying of wood in the winter months, or when lumber is stored in wood piles outdoors before the kiln drying process. In these cases, the wood freezing process increases the degree of freezing of the wood, subsequently significantly affecting the process of its heating during further processing (for example, in the cutting process). The most common method is heating by humid air, during the hot air drying of wood. We analyzed the temperature profiles on a cross-section of wood and moisture losses due to the freezing process and the size of moisture gradients. We compared theoretical calculations of the time required for defrosting and heating of wood with the experimentally measured values. The results show that the moisture content (MC) of wood has a remarkable effect on the wood freezing process. In samples with an average MC of 35.47%, the temperature drop was faster. After 10 h, the temperatures on the entire cross-section of the samples reached the lowest value of −13.2 °C. In samples with an average initial MC of 81.38%, three stages of temperature reduction in the wood were observed. The temperature dropped and the lowest temperature of −20.11 °C was reached after 24 h. The defrosting and heating process of samples with lower MC was significantly easier. The desired temperature of 65 °C in the middle of the samples was reached in 2 h and 20 min. The total time to defrost and heat the second group of samples (MC > FSP) was 3 h 30 min.
- Subjects :
- 0106 biological sciences
0209 industrial biotechnology
Technology
Materials science
Kiln
QH301-705.5
QC1-999
Lowest temperature recorded on Earth
02 engineering and technology
01 natural sciences
Degree (temperature)
moisture gradient
020901 industrial engineering & automation
Defrosting
Wood processing
010608 biotechnology
heating process
General Materials Science
Wood moisture
water in wood
Biology (General)
Instrumentation
Water content
QD1-999
moisture content
Fluid Flow and Transfer Processes
Moisture
Process Chemistry and Technology
Physics
General Engineering
Pulp and paper industry
Engineering (General). Civil engineering (General)
Computer Science Applications
Chemistry
freezing of wood
pine wood
heating time
TA1-2040
Subjects
Details
- Language :
- English
- ISSN :
- 20763417
- Database :
- OpenAIRE
- Journal :
- Applied Sciences; Volume 11; Issue 13; Pages: 6099
- Accession number :
- edsair.doi.dedup.....c42873367bb76ecf8fdb048f57a7140b
- Full Text :
- https://doi.org/10.3390/app11136099