Continuous Solvent Extraction Plants

SPECTEC offers continuous solvent extraction plants with latest technologies
Mechanical method is the combo of high pressure, high temperature,& high moisture, which causes color fixation, oxidation, hydrolysis. Some seeds like rice bran & soya cannot be handelled by the expellors. Continuous solvent extraction plant does not cause any alteration to the properity of oil and recovers it with the characteristics as where present in the raw material and can handelled all materials.

Capacity – 50 Tpd To 2000 Tpd
SPECTEC continuous solvent extraction plant consists of

  • Seed preparatory section
  • Solvent extraction section
  • Distillation section
  • Meal desolventising section
  • Recuperation section
  • Meal conditioning section

Seed Preparation

Preparation is the process of properly preparing seeds for extraction of oil either by solvent or mechanical method. While a particular seed may contain from 20 % - 50 % oil, the oil is tightly bound within the cell & mechanical action must be taken to either forcefully remove the oil or to make the oil accessible to subsequent solvent extraction. The unit operations typically involved are scaling, cleaning, cracking, conditioning (or cooking ) & flacking. Depending on process & oilseed in question, process drying and hulling may be employed, as may expander and collect dryer/coolers.
Solvent extraction process typically uses a flammable solvent, the operation is usually removed from the other facilities, and asses to the controlled area is restricted. Unit operation associated with solvent extraction includes extraction, solvent deistillation & liquid-phase recovery. Solid phase extracted material is desolventized, tosted, dried & cooled prier to meal finishing.
Extractor is a countercurrent flow device, the solid material moves in an opposite direction of solvent-oil miscella with an increasing oil concentration. As the material to be extracted enters the unit,it is contacted with miscella at the nearly ful oil concentration. After this first wash,the miscella,containing around 20-30% oil,leaves the extractor for solvent distilition and recovery. After passing through the various washing stages, finally being contacted with fresh solvent and allowed to drain for a brief period, the extracted material, commonly known as white flakes, is removed from extractor and is conveyed to the desolventizing process.

Solvent Extraction Section

Welcome to the SPECTECs Solvent Extraction Process
The main objective of the extraction process is to reduce oil contain in oilseed to the minimum possible level. The chain conveyor from preparatory transfers the prepared material to the Rotary Airlock Feeder, which further drops it to the feeding hopper. Rotary airlock feeder ensures the effective vapor seal also the regulates the feed. Hopper is provided with the special flameproof level switches for the indication of high and low level. So as to enable to generate audio signal in the situation of high level, for preparatory operator to take corrective actions. SPECTECs Extractor is a mild steel construction rectangular vessel, installed horizontally. Pretreated material from preparatory moves on the specially designed articulated band conveyor inside the extractor. Band conveyor speed is adjusted according to the process demand. Band conveyor insures the continuous travelling of the feed material from feed end to the final end with determined speed, pre-calculated bed height and under the continuous solvent spray. Bed of the feed material on band conveyor is adjusted by adjustable damper. Band conveyor cleaning is accomplished by high pressure jet spray of fresh solvent on to the return of band conveyor at discharge end which ensures perfect cleaning of mesh and completely eliminates the possibilities of mash choking & channeling.
SPECTECs specially designed spray breakers ensures the uniform distribution of solvent over the entire width of moving bed. Fresh solvent is admitted into the extractor near the discharge end of the moving bed of the material and the full miscella is recovered from the initial stage, thus ensures the perfect counter current flow of the material and the solvent. The miscella circulates in a closed circuit in each of the successive section by overflowing from each hopper. So in each section there is an equilibrium between the oil extracted from the seed in corresponding section and the difference in oil content of solvent overflowing the preceding hopper together with the solvent overflowing the following section.

Solvent Distillation Process

Special features of SPECTECs Economizers

  • Reduces the steam consumption.
  • Increases the capacity of distillation section.
  • Increases the capacity of condensing section.

The miscella from the tank is pumped through the vapor economizer, to the first evaporator. The economizer unit is specially designed in order to effectively utilize the heat of vapors emerging from the desolventizer toaster.
The concentrated miscella thus obtained from the economizer unit is rapidly heated in the first evaporator by means of low pressure steam and enters into the flasher, where solvent vapors are flashed off. The oil rich miscella thus obtained is charged into the second evaporator & stripper. The flashed of solvent vapors are condensed into the condensers & liquid solvent is recirculated back to the process through solvent water separator. Distillation system operates under high vacuum & lower temperatures & short distillation period ensures good quality of oil. Further more the distillation system is coupled with a final drying of oil in final oil heater, which results in production of oil with exceptionally low volatiles in it.