Vacuum receivers Perkin

The dotted line in Fig. 11,17, 2 refers to the modification of the apparatus for use in fractional distillation under reduced pressure a Perkin triangle or equivalent receiver device ( vacuum distilling adapter ) is generally employed for collection of the various fractions. 

Attach the flask containing the mixture, with capillary in position, to the column make sure that the Perkin triangle (or vacuum distilling adapter ) and receiver are in place. See that the oil pump is functioning... 

The chief disadvantage of the simple vacuum distillation set up shown in Fig. 11,19, 1 is that, if more than one fraction is to be collected, the whole process must be stopped in order to change the receiver B. It is of value, however, for the distillation of solids of low melting point the distillate can easily be removed from the receiver by melting and pouring out. For routine work, involving the collection of several fractious under reduced pressure, the most convenient receiver is the so-called Perkin triangle the complete apparatus for vacuum distillation is depicted in F g. 11,20, 1. The Claisen fla.sk A is fitted to a. short water... 

The vacuum distillation adapter also shown in Fig. 2.106 allows the collection of fractions when distilling under reduced pressure. Its operation is similar to the Perkin triangle or equivalent device ( intermediate receiver adapter ) described in Section 2.27. The general technique of conducting a fractional distillation is as follows ... 

For vacuum fractional distillation of liquids having close boiling points, which necessitates the use of a total condensation variable take-off head, the receiver adapter modification noted in Fig. 2.106 is employed. Its operation is similar to that of the Perkin triangle the column is operated under total reflux while the receivers are being changed. 

The high efficiency and small pressure drop of the spinning-band columns (Fig. 2.107) makes them very suitable for precision vacuum fractional distillation. The still-head is provided with a type of Perkin triangle assembly which allows the receivers to be changed without disturbing the column equilibrium. 

Attach a receiver to the Perkin triangle and open both the apparatus and the receiver to the vacuum using taps A and B. 

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