PIC – EL-ARC – note, sensor pipe was lengthened later From LM heads product takeoff you have a copper pipe (8-10mm have been successfully tested) that is sealed at the bottom end, goes down 80% of packed column height (i.e. 80cm pipe for 1 meter column) and is soldered to the outside of column pipe to get good heat transfer. About 20 cm from the top of the pipe is the actual products take off. From the takeoff we have vapor lock and the pipe goes up again to 1-2cm below the liquid surface on LM reservoir and back to collection vessel. On the highest point of this product takeoff is a ventilation hole to prevent siphoning (required for at least smaller pipe diameters). Note, in the picture I have used silicone hoses. I recommend you use a 5-6mm copper pipe instead.
The principle of operation is that the liquid at the bottom of the 80cm pipe will boil if the temperature at the lower parts of the column where the pipe is attached is higher than the boiling point of liquid inside the sensor pipe (in practice 78.1-2C since it’s the first stuff that reaches the top of the column). When the liquid boils no liquid will enter the product takeoff tube, but all is returned to column via LM head due to pressure difference. When the temperature at the column (in the part where the pipe is soldered to) evens out the boiling stops and liquid will start to flow out of the product takeoff. This causes less reflux and the temperature in the lower part of the column starts to rise. When it’s high enough the output stops and the cycle starts again. In practice this works very well. It adjusts the reflux ratio automatically and stops the collection before any higher boiling point alcohols have a chance to get to the top of the packing. This system gets rid of the tails but there is still the problem with heads. Several methods to get rid of the heads are researched, but I’ll present here the simplest one.
PIC-heads-collection-bottle With this system the heads will go to the bottle, and when it’s full to the set limit (ventilation hose/pipe inside the bottle) product will start to flow to the collection vessel. The amount of heads can be adjusted by varying the length of the hose/pipe inside the bottle. The ventilation pipe/hose needs to go above the point where pipe to product vessel leaves, as liquid inside the ventilation pipe will rise to this level. The vaporlock in the tube prevents heads in the bottle from contaminating the product and also enables the adjustment by vent pipe. Otherwise the liquid in the bottle would rise up to the actual feed tube bottom. I recommend this type of system to be built from 8mm pipe as minimum diameter.
Now the latest innovation for removing heads (pioneered by “Farbror Plast”) is to use separate heads column for that. In practice this means that we have another column that’s closed at the bottom and the bottom of that column goes down to mash in boiler. This gives enough heating for the column to let it operate normally. The product from ARC column goes to top of packing of this heads column. At the top of the column we have condenser as usual, and below the condenser we have a reservoir of 100-150ml where heads will be collected. The pure ethanol is taken out from the bottom of the column. Now the biggest problem with this type of approach is that at the start the column is fed with lots of heads and at the end there’s mostly pure ethanol. This means that we need to give the column some time to stabilize before we start taking product out. Two methods for this have been identified so far: 1. We let the ethanol pool at the bottom of the column and when adequate level is reached it starts to flow out. Finding a proper level requires experimenting but this has been tested to work. 2. We collect all the reflux below the packing and feed it back to column via needle valve. When there’s enough reflux flowing the needle valve will restrict the flow and some pure ethanol will start to come out
Direkte link til boka ligger her
http://distillers.tastylime.net/library ... /index.htm
Flere bøker finnes her
http://distillers.tastylime.net/library ... .htm#Books Listings
Spørsmål stilles i tråden her
og beklager store bilder 
