What is the use of reflux divider and how it works in distillation? How we can adjust the reflux ratio in a manualy operated fractional distillation?
Reflux divider is a pneumatic valve located between condenser and top of the column.
It helps in maintaining the desired reflux ratio in distillation column. It will be closed for some time and open for some time depending on the reflux ratio provided.
As of my knowledge, in manual operated distillation column, reflux ratio is operated in terms of time (considering vapor flow rate is constant) i.e., if you say reflux ratio is 5:1 then reflux divider will be closed for 5 sec (will not allow any condensate to pass through) and will open for 1 sec (allow the condensate to pass through). In other words, your condensate from condenser will return back to column for 5 sec and get routed out as distillate for 1 sec.
If you change the reflux ratio, the reflux divider action also change accordingly.
Hope you understand!!
regards
Sairmu.
@ sairmu : good explanation
we offer Digital controlled ration which sends a signal to magnet which in tern would pull or push a metal disc embedded in glass plate.
The type of reflux divider that I am familiar with, which is used in glass laboratory columns, is called a Liquid-Dividing Head. It is usually located between the top tray of the column and the condenser. The condenser is usually updraft (vapor flows up from the column, condenses, and flows back down the inside of the condenser, countercurrent with the vapor, back to the top of the column). The Liquid-Dividing Head is a glass section that has a "swinger", which is a glass tube mounted on a hinge with a piece of metal or a magnet attached. When the tube is in its resting position, liquid from the condenser flows to the top of the column. When the tube is pulled to the side, liquid from the condenser flows out of the column as distillate. An electromagnet with a timer controls the swinging motion (which controls the reflux ratio).
The Liquid-Dividing Head can also be used within the column to enable the removal of a sidestream. However, in this case, you have to worry about venting the sidestream make line back to the column, and you must have a nitrogen blowback to prevent vapor from leaving the column.
Glenn Graham
The relux flow in manualy operated colum can be adjusted by throttling the valve in reflux flow line and fine tuning it
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