Abstract: 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.

Abstract: The invention relates to a closure system for pressure vessels, the closure consisting of a cover and of two clamp halves each of which can be moved into closing or open position by means of guiding elements. The clamp halves, the cover, and the pressure vessel housing being equipped with stop surfaces, the stop surfaces of the clamp halves being opposite to those of the cover and of the pressure vessel housing in closing position. The closure system is especially suitable in cases where an entirely automatic closing device is required for pressure vessels having an operating pressure of more than 10 bar.The clamp halves are connected by means of tensible flexible bearings to guiding elements to allow for a cover movement in axial direction. The tension of the flexible bearings is sufficient for automatic resetting of the clamp halves into zero position after depressurization of the vessel.