MATHEMATICAL DESCRIPTION OF SPEED OF VACUUM DRYING OF TIMBER

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-13-3 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 62, 247-254 pp, DOI: 10.5593/sgem2017/62/S26.032

ABSTRACT

One of the directions of rational use of energy resources in the field of drying of wood is the use of the managed heat pumps having the considerable potential for reduction of primary energy consumption when drying. Heat pumps can be used in combination with traditional fuel or electricity as an additional power source, or to act as the independent generator of heat and at the same time as draining device. The advantage of heat pumps is lower energy consumption for each unit of remote moisture, more exact management of conditions and process parameters of drying and achievement of the improved product quality. However heat pumps haven’t find application in technologies of vacuum drying of materials yet. The technology of oscillating vacuum and conductive drying using the heat pump was developed for the purpose of cost reduction in the processes of vacuum drying of timber. At the same time calculation of the heat pump requires a task of thermal loading determined by the speed of evaporation of moisture from material. In this regard the results of pilot study and mathematical data processing of a stage of degassing of previously heated wood sample are given in the provided article. The received expressions allow us to define change of characteristics of process of drying depending on regime parameters and a gage of the dried-up timber and can be used in case of projecting calculations of the heat pumping equipment for vacuum drying chambers.

Keywords: wood, vacuum and conductive drying, heat pump, drying speed