The extract obtained by the trickling or filtering process is much more concentrated than that obtained by the steeping and flooding process.
Adamson’s Method for Treating Substances with Hydrocarbon Vapor for the Purpose of Extracting Oils, Fats, etc. This improvement is intended to prevent the fetid or other odors imparted to the vapor from the substances treated from being recommunicated to the said substances, and to the extracts obtained therefrom through the medium of the vapor from the re-used hydrocarbon. The vapor is obtained from benzine, benzole, etc.
Fig. 33 represents, partly in section, the apparatus whereby the invention may be carried into effect.
A is a vessel in which the substances have to be treated by hydrocarbon vapor, the said substances being introduced into the vessel through a manhole, x, and deposited on a perforated diaphragm, B, the manhole being provided with a suitable cover. A steam-coil, D, is placed in the vessel in a space beneath the diaphragm, and liquid hydrocarbon is introduced into the said space, and is there vaporized by the steam-coil. The vapor rising through the perforated diaphragm permeates the substance upon the same, so as to extract therefrom the oily, fatty, or resinous matter, which passes downward through the diaphragm into the space below the same, whence it may be drawn off from time to time through the discharge-pipe j. Liquid hydrocarbon may be introduced from a tank, or from a source explained hereafter, into the top of the vessel A, so that it will pass through the material and be vaporized when it reaches the coil; the said material being in this case subjected to a downward current of liquid hydrocarbon and an upward current of vapor.
Previous to this invention it was Mr. Adamson’s practice to cause the vapor, after acting upon the substances in the vessel, to pass through a worm in a condenser, the lower end of the worm communicating with the vessel, A, beneath the diaphragm, as shown in Fig. 35, p. 85, so that the hydrocarbon was used over and over again. But in practice this has been found objectionable in many cases for the following reason:—
In treating animal offal, for instance, for the extraction of fats, fetid odors are imparted to the hydrocarbon vapor, and remain, to a considerable extent, in the condensed vapor when the latter is restored to the vessel A; hence, the fetid odors were recommunicated both to the fatty extracts and to the material. The same objections have been experienced in treating meat for preservation and vegetable matter for the extraction of oil by hydrocarbon vapor.
This difficulty is obviated in the following manner: The vapor-pipe D´ communicates with a vessel H at the top of the same, and the vapor is met by numerous small jets of cold water—in the present instance, from a perforated tubular ring, m, into which the water is forced through a pipe n.
Many different appliances may be used, such as roses, revolving jets, etc., for causing a spray through which the vapor must pass, and by which it must be condensed. The result of this will be a supply, I, of tainted water on the bottom of the vessel, H, and a quantity, J, of washed and purified hydrocarbon above the water, the latter having taken up the fetid odors.
The washed hydrocarbon may be drawn off through a pipe, g, into any suitable vessel, and thence introduced through the pipe h into the vessel A, or may pass directly into the latter to be again vaporized therein, the vapor after permeating the material and passing through the pipe D´ being simultaneously condensed and washed in the vessel H, preparatory to being returned in the condition of purified liquid hydrocarbon to the vessel A.
Fig. 33.