GB372507A - Process and apparatus for the continuous rectification of acetic acid - Google Patents

Abstract

<PICT:0372507/III/1> <PICT:0372507/III/2> Acetic acid is rectified continuously by feeding it from a tank A through a valve C into a column G provided with a boiler K the impure concentrated acid being further purified by feeding it through a pipe 7 or from the lower plates T of the column into a second column N surmounted by a condenser O in which the crude acid is preheated and a condenser P in which impurities are condensed and returned through a separator Q to the column while the pure acid vapours are condensed in a silver coil L and are passed through a test safe l to storage. The light impurities concentrating at the head of the column pass into a reflux condenser H and are separated in a separator J into a portion which is returned as reflux through a pipe 15 and a part which is run off through a receiver R for further rectification in a column g. The heavy impurities are allowed to collect in the boiler K and are run off intermittently through a cooler M for rectification in the column g. The level in the boiler K is maintained constant by providing a float v, Fig. 2, in a container V communicating by pipe W, W<1> with the boiler K, the float being connected by a chain running over pulleys X, X<1> to the valve C. The impurities are rectified in a column g provided with a boiler k and a condenser h from which fractions are run off through a bottle j and test safe r provided with cocks q for the different fractions. The residues from the column are returned through a pipe 23 to the boiler k or at the end of the distillation to the cooler M.