1. Extraction
By Moizul Hasan
Assistant Professor

2. Batch extractor
Seed flakes
solvent
cake
miscella

3. THE FİXED-BED OR ROBERT DİFFUSİON BATTERY
This was developed primarily in the beet-sugar industry, but is also used for the extraction of tanning extracts from tanbark,
for the extraction of certain pharmaceuticals from barks and seeds, and similar processes. It consists of a row of vessels filled with the material to be extracted and through which water flows in series.The piping is so arranged that the fresh water comes in contact with the most nearly extracted material, and the strongest solution leaves from contact with the fresh material.Since each cell is filled and discharged completely ,

4. one at a time, each cell in the battery changes its position in the cycle,and therefore the piping must be so arranged that water can be fed to any cell, and the thick liquor drawn off from any cell, as circumstances may dictate.The arrangement of valves and piping became standardized in the beet industry and is generally found an all forms of diffusion battery. Figure shows that is a diagrammatic illustration of the principle of a diffusion battery.For every vessel or cell there is a heater, because the diffusion process takes place more rapidly at higher temperatures.Two main headers are necessary .One handles water and the other handles solution;and for every cell there must be three valves.In figure shows that the valves that are open are shown as circles and the valves that are closed are shown in solid black.

5. Fig.Diagram of diffusion battery

6. Consider figure; Cell 1 is nearly exhausted and the cell 3 has just been charged.The space between the cossettes in cell 3 is therefore filled with air.Water is introduced into cell 1 and flows down through cell 2, and up through its heater.It would not be convenient to pass the solution down through cell 3 because of the air which would be entrapped;and the charge is cold, therefore additional heating is desirable.Consequently, the liquid flows from the heater of the cell 2 through the solution line, down through the heater of cell 3,and up through cell 3. A vent at the top of this cell discharges air.When liquid appears at this vent, the valves are quickly changed to the position shown in figure.Liquid now flows down through cell 3, up through its heater, and out tı the process.The operation shown in figure continued until cell 1 is completely extracted.By this time another cell to the right of those shown has been filled, cell 1 is dumped, water is introduced to cell 2, and the process continued.In a diffusion battery for beet cossettes there may be from 10 to 15 cells.

7. CONTİNUOUS DİFFUSİON BATTERİES
The next figure shows the Silver Continuous diffuser.The figure shows only three units; but actually the battery consists of 20 to 24 units arranged in two tiers, one above the other.The battery consists essentially of a series of closed troughs A,A’,A’’, each provided with a helical screw B.Cossettes are intoduced into the battery through chute C and are carried together with the liquid in the direction indicated by the arrows.At the end of the first trough is a Wheel D with inclined perforated buckets on the inside.It is so arranged that the screw B discharges the cossettes into this wheel, where they are picked up by the buckets;drained free from juice lifted, and discharged through chute E which takes them into the second trough A. Here the helix carries them in the opposite direction discharges them from this to another wheel which in turn forwards them to another trough A’’, and so on until they are exhausted and leave the battery.

8. Roto-cell extractor (Reflex extractor-DeSmet)

9. Rotocell extractor

10. Rotocel Extractor

14. Podbielniak Horizontal centrifugal extractor High efficiency
Short residence time
Minimum inventory

15. Figure.Podbielniak contactor

16. Podbielniak

19. BOX PRESS PLATEN PRESS

20. POT PRESS CURB PRESS

21. CAGE PRESS

22. SCREW PRESS