Читать книгу Osmosis: The Molecular Theory - Larry Howlett - Страница 11

Seed stored in a hermetic container is shown in figure 5. As noted, the seed exchanges heat and moisture with the atmosphere within the hermetic container but only exchanges heat between the hermetic container and the external atmosphere. We look at seed stored in a hermetic container from a macro viewpoint. The macro model data is shown in table 1.

Initial properties of the seed are values S1 through S3. The corresponding initial properties of the atmosphere are taken equilibration chart figure 2, values (A1, A2). Additional properties of the atmosphere within the hermetic container are found from psychrometric charts and tables. A short version of a psychrometric chart is shown in figure 3. From the properties of the seed and the atmosphere within the container, and assuming one cubic foot of seed and air within the hermetic container, we calculate that the total mass of seed and water within the seed is much greater than the total mass of air and water vapor in the air. (values S4-S6 & A5-A8, table 1)

If we raise the storage temperature to 90ºF, The atmosphere properties (A9 – A13) show that the maximum moisture content in the air within the hermetic container is much less than the total water content of the seed. For practical purposes, the seed water content will remain constant at the initial value of 15%. We note that this is agrees with the experimental data.