Double-jacketed coil condenser

There are many different designs of condenser available, and the type used depends upon the nature of the reaction involved. The most common designs of condenser are the Liebig condenser (Fig. 9.25a), the coil condenser (Fig. 9.25b), the double-jacketed coil condenser (Fig. 9.25c), and the cold-finger condenser (Fig. 9.25d). Other condensers available tend to be simple modifications of these three types. 

The Liebig condenser, the coil condenser, and the double-jacketed coil condenser are similar in design and function. They are water-cooled via connection to a cold-water tap, in the case of the Liebig condenser the water flows in at the bottom and flows out at the top giving a jacket of cold water around the condenser stem and leading to a cold surface on the inside. Any volatile materials in the reaction condense on the cold outer surface and run back into the reaction mixture. The coil condenser functions in a similar way except that the cold surface is now on the inside of the condenser. This can offer an advantage in particularly humid locations because there is less tendency for atmospheric moisture to condense on the outside of the condenser and run down over the reaction vessel. The double-jacketed coil... 

Coil condenser. An open tube, into which is sealed a glass coil or spiral through which water circulates. The tube is sometimes also surrounded by an outer cooling Jacket. A double coil condenser has two inner coils with circulating water. 

Mg. 11, 56, 17 (Davies types) and Fig. 11, 56, 18 (double coil type) are examples of efficient double surface condensers. Fig. 11, 56, 19 depicts a screw type of condenser (Friedrich pattern) the jacket is usually 10, 15 or 25 cm. long and the cone and sockets are fil9 or 24 this highly efficient condenser is employed for both reflux and for downward distillation. 

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