| 摘要 |
A process and apparatus for extracting ingredient substances from natural products by means of a pressurized fluid, particularly for decaffeinating tea leaves by means of carbon dioxide, wherein the ingredient substances are bound by an adsorbent, preferably activated carbon. The fluid is conducted through a product layer, the thickness of which in flow direction is small in comparision with that transversely of the flow direction and the fluid is passed through the product layer with changing, especially increasing, velocity. The apparatus includes a cylindrical high-pressure vessel with annular cylindrical baskets for accommodating the natural product and/or the adsorbent, and the gas flows from a cylindrical outer range to a cylindrical inner range. The time required for the treatment of leafy natural product is reduced, the flow paths of the fluid are shortened, thus diminishing the risk of clogging, and the fluid flow velocity is reduced.
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