GB486169A - Improved process and apparatus for the extraction of liquid from cashew nut shells - Google Patents

Abstract

<PICT:0486169/III/1> Oil is extracted from the shells of cashew nuts by subjecting a column of nuts, or of broken shells, in a container to a downward current of superheated steam, and draining the oil and condensed steam from the bottom of the container, the uncondensed steam from the container being admitted to a second container to preheat the shells therein. After the treatment with superheated steam, saturated steam may be passed through the hot shells in the container, the resulting superheated steam being used to preheat the shells in the second container. Apparatus for carrying out the process may comprise a series of containers a each provided at the top with a charging door d and a valve-controlled inlet a2 for superheated steam from a pipe j, and at the bottom with a valve-controlled outlet e and a valve-controlled pipe i leading to the top of the succeeding container. In use, superheated steam is admitted to each container in succession, the condensed steam from each container being admitted by the pipe i to the succeeding container to preheat the shells therein. Oil and condensed steam collect in the bottom of the container and are discharged through the outlet e. Uncondensed oil vapour is carried forward by the uncondensed steam into the succeeding container when it condenses. A supply pipe k for saturated steam connected to the inlets a2 may be provided, in which case, after the superheated steam is cut off, saturated steam is passed through the hot shells, the resulting superheated steam being admitted to the succeeding container as a preheating agent. The shells may be supplied to the containers by an elevator E feeding a screw conveyer l the casing l1 of which is provided with outlets l2 controlled by slides l3. Specification 472,195 is referred to.