| 摘要 |
The invention relates to a heat treatment process for disinfection of seeds from pathogens and other undesirable fungi and bacteria, the process being characterised by supplying to the seeds non-water-borne heat while regulating the treatment time and temperature with regard to the condition and moisture content of the seeds in such a way that the seeds are heated from outside and in, while evaporation of moisture from the surface of the seed, and owing to that, cooling of the same is prevented and no changes in the moisture content occur. The process of the invention is further described below with reference to the embodiment in the figure shown. This embodiment of the process according to the invention is carried out continuously in five phases which are the following: (A) A feeding phase where the layer thickness of the seeds fed is regulated so that the subsequent heating phase guarantees a homogenous heating; (B) A heating phase where the seeds, by supply of hot air, are heated to a predetermined treatment temperature, the heating phase being as short as possible and being performed so that the moisture content of the seeds will not be changed. Evaporation if any, from the seeds results in energy being used for the evaporation instead of for heating and thus counteracts an efficient heating. The time in this treatment phase must, however, be long enough to allow the seeds to reach the predetermined treatment temperature. This is the most sensitive as regards to both the quality and the capacity. (C) A treatment phase where the seeds are treated by keeping them warm during a calculated treatment time with constant temperature and moisture content; (D) A cooling phase where the seeds are rapidly cooled in order to control the treatment time; and (E) An output phase where the disinfected seeds are withdrawn.
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