According to the initial content of oil and fat in raw materials, it is possible to execute the direct solvent extractio...
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Solvent extraction - forward In the field of the oily seeds and other natural raw materials, one of the most utilized systems for obtaining oils and crude fats, is surely the Solvent Extraction. According to the initial content of oil and fat in raw materials, it is possible to execute the direct solvent extraction or a previous reduction of the fat content by means of pressing or pre-pressing, followed by solvent extraction of the oil from the solid residue of the pre-pressing (cake). A correct preparation of the material (generally consisting in mechanical or thermal processes) is very important to guarantee the best results in extraction. The most widely used solvent is still hexane, mainly due to its high selectivity and in spite of the negative factors that this solvent presents as far as safety is concerned.
Counter-current extraction
MISCELA RICCA MISCELLA RICHE RICH MISCELLA MISCELLA RICA
MATERIALE DA ESTRARRE MATERIEL A EXTRAIRE MATERIAL TO BE EXTRACTED MATERIAL A EXTRAER
SOLVENTE PURO SOLVANT FRAIS FRESH SOLVENT SOLVENTE FRESCO
MATERIALE ESAURITO MATERIE EPUISE’ EXHAUSTED MATERIAL MATERIAL AGOTADO
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Selection of solvent extraction system When evaluating and selecting the extraction process, it is most important to bear in mind that the plant should satisfy the following requirements: a) to assure an efficient and uniform contact between the solvent and the material to be extracted, without originating cloggings nor canalization or preferential ways; b) to reach a deoling degree which results interesting from the economical point of view in the shortest possible time (that is with the minimum operative volume and with the maximum efficiency of the washing systems); c) to obtain an oil/solvent clean mixture with high oil concentration; d) to rely on simple and strong equipment, provided with few moving parts requiring minimum maintenance and assuring easy access and facility of inspection in all parts; e) to grant high flexibility so that the working conditions can be optimized according to the characteristics of the raw material; f) to be very compact and designed in the respect of the most rigorous safety standards. Our Company has designed and realized a plant capable of satisfying all these requisites: the circular extractor TURNEX. It is proposed in a wide range of sizes and working capacities from 50 to 5000 t/24 h and more. The Extraction Plant mainly consists of the following stages: - Solvent Extraction - Desolventizing (and eventual Toasting) of the deoiled meal - Miscella Distillation - Solvent Recovery The process flowdiagram of the Extraction & Desolventizing section is represented in the drawing A (para 3). The process flowdiagram of Miscella Distillation section is represented in the drawing B (para 5). The process flowdiagram of the Solvent Recovery section is represented in the drawing C (para 6).
General view of a Turnex plant
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“Turnex” circular extractor The “TURNEX” circular Extractor is a continuously working unit for counter current solid-liquid extraction (drawing A). The TURNEX typically works by percolation but it can also assure the complete flooding of the solid material. The extractor consists of a cylindrical casing with vertical shaft, absolutely tight to solvent vapours, provided with a fixed horizontal filtering floor. An annular rotor, divided into compartments or cells without bottom, rotates on the filtering screen and receives the product to be extracted in a point of the run; by rotating, it conveys the material by making it slide on the filtering bottom up to the end of the circular run. At this point, the filtering bottom is missing in one sector and, consequently, the exhausted material falls into a hopper, from which it will be sent to the following treatment (desolventizing).
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“Turnex” circular extractor The rotor is supported by one or more pinions, driven by an oleodynamic system at variable speed enabling the extraction time to be changed. These pinions, which are very simple and strong, are the only moving parts of the whole extractor besides, of course, the rotor; there are no chains nor creeping parts or cams nor other parts subject to movement nor wear whatsoever. The fixed filtering bottom is completely manufactured of stainless steel. A set of trays, placed under the filtering bottom, collect the miscellas at different concentration (recycled through a set of pumps) and receives, as last washing, a pure solvent rain (counter current extraction). The solid material itself acts as a filter; the rich miscella is therefore clean when comes out of the extractor (it can be furtherly filtered only to safety purpose). The extractor is normally equipped with one working stage only but, according to working capacity, it is also possible to manufacture extractors having two or more working stages.
Turnex under construction
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Meal desolventizing The deoiled material is fed to the Desolventizer (drawing A, para 3) which, if requested, is also utilized for the meal toasting (soybean) through live steam injection. Modern units are often designed as to realize, in a unique apparatus, also meal desolventizing and cooling (these units are called DTDC desolventizer/toaster/dryer/cooler). Often, however, due to safety reasons, it is preferred to realize meal dehydration and cooling in units separated from the desolventizer.
Desolventizer
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Miscella distillation The rich miscella is distilled in different subsequent stages (at always more and more reduced pressure) up to obtain the crude oil (drawing B). The first stage is generally realized in the Economizer EV, which permits to realize considerable steam and water savings, as the miscella is evaporated under vacuum by utilizing the latent heat of the vapours coming out of the desolventizer DT which are so condensed.
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Solvent recovery The vents coming from all the equipment are collected in a unique header and processed in a solvent recovery unit before being discharged to atmosphere. The solvent recovery section is based on an absorption system with mineral oil (drawing C). To increase the recovery efficiency, the vents can be cooled by a frigorific compressor before being sent to absorption.
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Solvent recovery
Miscella distillation and solvent recovery
We are pleased to inform you that Gianazza International has acquired the rights to Gianazza Technology. We have over 250 successfully operating plants for edible oils and fats refining as well as more than 300 plants for oleochemicals throughout the world. Considering the world continuous evolution, Gianazza International is determined to continue Gianazza's century old commitment to quality and focus on core business of introducing new technologies, plants and facilities as well as providing the necessary parts needed to maintain a first class production. We are confident to appraise our customers that the Gianazza International has the technology and the know-how of Gianazza under a new structure in order to offer reliable services for years to come. We have the support of skillful personnels from Gianazza who trust in more than 120 years of experiences our company has gained since 1892. Gianazza International is devoted to provide long term satisfaction to our customers.
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