Установка для экстракции растворителями

Prepared seed from preparatory section / full pressed oil cake / pre-pressed oil cake / expanded material is carried by Redler Conveyor and fed to Extractor either through a rotary valve or Plug O Seal to extractor feed hopper incorporated with a high and low-level arrangement to ensure a proper level of material filled in the Hope and seal for the system. The material through the intake hopper moves on the endless band conveyor chain of moving deep bed extractor and the Hexane is sprayed counter currently over the moving bed material. The solvent percolates n penetrates through the bed and dissolves oil with it. The solvent oil mixture is called Miscella.

Miscella from the last hopper will be transferred to the Miscella holding tank through Miscella filter or hydro cyclones fixed above Extractor. The de-oiled seed material with solvent is discharged from the extractor discharge hopper and is transferred to desolventisor toaster through leak proof sealed solvent tight conveyor.

Solvent extracted material will be heated with the use of jacketed and open steam in desolventisor toaster for removal of total solvent. Thus solvent evaporation desolventises the extracted seed material (Called as DOC or Meal). The desolventised material is further heated in presence of moisture and toasted to the desired limit for destroying undesirable enzymes present in DOC or Meal. Moisture level of desolventised material will be maintained with the help of sparge steam. The hot meal from desolventisor toaster will be transferred to Meal Conditioning/drying/sizing/bagging section.

Solvent vapour from desolventizer along with moisture fines are taken to wet dust vapour scrubber where fines are separated by using of hot water spray before fine free vapours are moved to condensation unit through heat economiser. Hot water is pumped from hot water reboiler after stripping of final traces of hexane through hot water circulating pump and sprayed in wet vapour scrubber. Water from wet vapour scrubber flows down to wastewater boiler completing a close circuit loop. All solvent vapours coming out with washed water from wet vapour scrubber to wastewater reboiler will be moved to condensation automatically. The final DOC/meal will be transferred meal conditioning and bagging section.

Solvent vapour free of fines and hot moving out wet vapour scrubber will be moved to economiser in shell side. Filtered Miscella from Miscella tank is pumped to economiser in tube side of Economiser. In this process Miscella gets heat exchanged from vapour and heated flow through the flasher and get concentrated and vapours from Miscella taken to distillation condenser. Vapours from economizer shell are carried for condensation flasher to condenser.

Concentrated Miscella from economizer flasher is pumped to 1st evaporator where it is charged to tube side and heated by steam in shell side. Hot Miscella then gets separated in flasher and concentrated Miscella obtained is sucked by vacuum to 2nd evaporator/flasher where it is further concentrated (upto 98% concentration). This concentrated Miscella is then pumped and sprayed to the stripping column. The stripping column is working under vacuum 650 – 700 mm hg and is provided with special spray as well as baffle arrangement for the formation of thin-film to expose solvent on the surface of the oil. Oil from the stripper is then pumped to Vacuum dryer to remove minimize final PPM of solvent in the Oil taken to the cooling system either through heat recovery system and Oil cooler before transferring to an intermediate oil storage tank in the plant.

Solvent vapours emanating from desolventisor toaster are taken to first condenser through economiser and vapour emanating from economiser to condenser called DT Condenser. Vapours from 1st evaporator is taken to 1st condenser, Vapour from 2nd evaporator to 2nd condenser, vapours & from recuperation evaporator taken to 2nd condenser The uncondensed vapours and equipment vent vapours are taken to the vent condenser. The liquid solvent plus water from all four condensers is taken to solvent water separator where water and solvent are separated. The separated solvent pass through the cyclonic separated where the final traces of water particles will be removed and is recirculated to extractor for processing and is loop process and continuous cycle is going on again and again.

The entire plant will be working under a vacuum. The air, entering through the feed material and by at leakage’s in pump gland, drive etc. will be exit out. During exiting of air from the system there will be carryover trace hexane (solvent). This solvent is specifically recovered using a recuperation system. The uncondensed vapours along with entrained air are taken to an absorption column filled with pall rings where it comes in contact with thin film of cooled absorption oil, which absorbs solvent vapour due to its affinity to mix with oil. While air free from solvent is taken to the atmosphere through a final air vent.

The absorber oil mixed the solvent vapour is transferred for recovery of solvent to evaporator / stripping column through oil in the oil heat exchanger and steam heater. In desorption column, oil is heated up vapours are evaporated and stripped off from oil and delivered to condenser while hot oil free from vapour and moisture is re-circulated to absorber through heat exchanger and surface cooler