IMPROVEMENTS IN THE PURIFICATION OF GLYCERINE
Year: 1885

page_text: I OTTO CHRISTIAN HAGEMANN of Buckingham House Twickenham in the
County of Middlesex Chemist do hereby declare the nature of my invention for
"IMPROVEMENTS IN THE PURIFICATION OF GLYCERINE" to be as follows:-
This invention has for its object improvements in the purification of glycerine.
At the present time it is usual to purify glycerine by distillation but it is found
that an appreciable amount of inorganic impurity passes over together with the
vapour.
Now I have found that much of this impurity may be removed by causing the
vapour on its way to the condenser to pass through suitably formed pipes or
channels sufficiently cooled by exposure to the air or otherwise to cause a slight
condensation to take place. I employ pipes or channels in the form of spirals or
volutes; there are a series of such pipes or channels arranged side by side in
parallel planes and they serve to connect a central main by which the vapour is
brought from the generator with an outer receiving main which leads the vapour
to the condenser. There is a receptacle on the receiving main into which the small
quantity of glycerine condensed in the spirals flows; this is drawn off from time
to time and is found to contain most of the impurities. The flow of vapour may
be inwards towards the centre in place of outwards the effect in either case is to
bring the condensed particles into contact with the walls or sides of the pipes or
channels so that they deposit thereon in place of remaining held in suspension
by the vapour.

page_text: The arrangement as shown in the drawings is suitable for a still producing about
four tons of glycerine per week.
The action is as follows:-
The vapour from the still carrying with it particles of common salt and other
mineral impurities flows with some velocity through the spiral passages and the
solid particles are thereby caused to impinge on the outer walls of the passages;
at the same time cool air is allowed to pass amongst the spirals in sufficient
quantity to cause some condensation of the glycerine within them. The interior of
the surfaces of the spirals are therefore always moist with glycerine-to these
moistened surfaces the solid impurities adhere and together with the glycerine
which is condensed they trickle down to the lower part of the passages and finally
they flow out into the receiver D. This receiver as is shown is furnished with a
gauge glass and the impure glycerine which collects in it is drawn off, whilst the
comparatively pure vapour passes on from the top of the pipe C to a condenser.
I find it suitable so to conduct the operation that about ten per cent of the
product may find its way into the receiver D but this may be varied according to
circumstances and the degree of purity to which it is desired to attain in this
apparatus by due regulation of the air current passing among the spirals the
proportion arrested in the receiver D is readily adjusted.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. The purification of glycerine vapour on its passage from the still to the con-
denser by causing the said vapour to pass through spirals volutes or other
continuously curved channels which are cooled to produce some condensation
within them whereby the non volatile impurities in the glycerine vapour are
brought into contact with moistened surfaces and are retained substantially as
described.
2. The purification of glycerine vapour by causing it to pass after it leaves the
still and before it enters the condenser through apparatus such as herein described
and represented by the annexed drawings.