Improvements in Purifying and Concentrating Glycerine, Applicable also to the Concentration of other Matters.
Year: 1885

page_text: Improvements in Purifying and Concentrating Glycerine,
Applicable also to the Concentration of other Matters.
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 PURIFYING AND CONCENTRATING GLYCERINE APPLICABLE ALSO
TO THE CONCENTRATION OF OTHER MATTERS" to be as follows:-
This Invention has for its object improvements in purifying and concentrating
glycerine applicable also to the concentration of other matters.
In the process of distilling glycerine it is found that an appreciable quantity of
impurities passes over together with the mixed vapours of glycerine and water.
In order to separate these and to obtain liquid glycerine in a pure and concentrated
form I cause the condensation to take place in apparatus resembling to some extent
apparatus now in use for vaporizing alcohol. The apparatus consists of an upright
cylinder or casing containing shelves or trays one above the other. The trays are
perforated so that the vapour which enters at the bottom is able to ascend through
the apparatus. Condensed liquor accumulates on the trays to a depth which in
each case is controlled by an overflow pipe. This pipe descends to the tray below
and there its lower end dips into a little well provided upon the surface of this
tray. The upper edge of the well rises somewhat above the mouth of the next
overflow pipe by which the liquor again descends from this lower tray.
The
The hot ascending vapour at every tray has to force its way through the layer
of liquid resting on the tray. The lowest tray is the first which the vapour meets
and it is the hottest; the liquid upon it is glycerine with little or no water.
vapour in passing through this liquid glycerine is washed and deposits inorganic
and other impurities. A. like action takes place on a tray or trays above until
practically all the impurities have been washed out. The vapour still ascending
through trays which are progressively cooler and cooler condensation take place
more and more rapidly. At first but little water vapour is condensed the liquid
deposited being a concentrated glycerine but at each successive tray more water
goes down and less glycerine because a considerable proportion of the latter has
already been removed from the vapour and deposited on the trays below.
the apparatus is properly worked the liquor on the top tray of the series will be
When

page_text: water containing scarcely any glycerine and the vapour in rising through it will
deposit the last of the glycerine leaving only steam which may be allowed to
escape.
The very weak glycerine deposited on the upper tray descends by the overflow
pipes from tray to tray and as it does so the water being the more volatile is
evaporated in larger proportion.
The water travels upwards as vapour whilst the glycerine travels downward in
the liquid state. On each successive tray in descending the series more and more
concentrated glycerine is found and the product when fully concentrated is drawn
off. The outlet is by a pipe passing to the exterior from the well of one of the
trays and several of the trays may be thus provided with means for drawing off so
that the most suitable level may be selected.
If the product be drawn off at too high a level it will not be sufficiently
concentrated. On the other hand if it be drawn off at too low a point it will not
have been sufficiently freed from impurities.
In like manner other vapours may be condensed to yield 'a' pure and concentrated
liquid.

page_text: Applicable also to the Concentration of other Matters.
I OTTO CHRISTIAN HAGEMANN of Buckingham House, Twickenham in the
County of Middlesex, Chemist do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention has for its object improvements in purifying and concentrating
glycerine applicable also to the concentration of other matters.
In the process of distilling glycerine it is found that an appreciable quantity of
impurities passes over together with the mixed vapours of glycerine and water. In
order to separate these and to obtain liquid glycerine in a pure and concentrated
form I cause the condensation to take place in apparatus resembling to some extent
apparatus now in use for vaporizing alcohol. The apparatus consists of an upright
cylinder or casing containing shelves or trays one above the other. The trays are
perforated so that the vapour which enters at the bottom is able to ascend through
the apparatus. Condensed liquor accumulates on the trays to a depth which in
each case is controlled by an overflow pipe. This pipe descends to the tray below
and there its lower end dips into a little well provided upon the surface of this
tray. The upper edge of the well rises somewhat above the mouth of the next
overflow pipe by which the liquor again descends from this lower tray.
The bot ascending vapour at every tray has to force its way through the layer
of liquid resting on the tray. The lowest tray is the first which the vapour meets
The
and it is the hottest: the liquid upon it is glycerine with little or no water.
vapour in passing through this liquid glycerine is washed and deposits inorganic
and other impurities. A like action takes place on a tray or trays above until
practically all the impurities have been washed out. The vapour still ascending
through trays which are progressively cooler and cooler condensation takes place
more and more rapidly. At first but little water vapour is condensed the liquid
deposited being a concentrated glycerine but at each successive tray more water
goes down and less glycerine because a considerable proportion of the latter has
already been removed from the vapour and deposited on the trays below. When
the apparatus is properly worked the liquor on the top tray of the series will be
water containing scarcely any glycerine and the vapour in rising through it will
deposit the last of the glycerine leaving only steam which may be allowed to
escape.
The very weak glycerine deposited on the upper tray descends by the overflow
pipes from tray to tray and as it does so the water being the more volatile is.
evaporated in larger proportion.
The water travels upwards as vapour whilst the glycerine travels downward in
the liquid state. On each successive tray in descending the series more and more
concentrated glycerine is found and the product when fully concentrated is drawn
off. The outlet is by a pipe passing to the exterior from the well of one of the

page_text: trays and several of the trays may be thus provided with means for drawing off so
that the most suitable level may be selected.
If the product be drawn off at too high a level it will not be sufficiently
concentrated. On the other hand if it be drawn off at too low a point it will not
have been sufficiently freed from impurities.
In like manner other vapours may be condensed to yield a pure and concentrated
liquid.
In order that my said invention may be most fully understood and readily
carried into effect I will proceed to describe the drawing hereunto annexed.
The drawing shows a vertical section of apparatus which I employ for the
purification and condensation of vapour of glycerine.
A A is a copper cylinder about one foot in diameter and fourteen feet or there-
abouts from top to bottom; it is made in sections and each section is furnished
with a jacket A¹ A¹ through which water may be circulated.
The ends C C are of brass and so also are shelves D D arranged at distances
apart within the cylinder which they fit closely. The shelves are supported by
legs D¹ D¹ with which they are provided. Each shelf is perforated all over its
flat surface with conical holes about one tenth of an inch in diameter at the top.
D2 is a well or receptacle with which each shelf is provided and a pipe D³ brings
down liquor into the cavity from the shelf above. Each shelf is furnished with its
overflow D³. I provide a series of columns such as that shown arranged side by
side and connected together in series the top of one column with the bottom of
the next. The lower part of the first column of the series receives from the still
mixed vapours containing glycerine, water, volatile impurities and non volatile
impurities; the latter being carried forward mechanically.
The vapour from the still entering at the bottom of the first column of the series
passes up through the perforations in the shelves and at each stage it passes
through a shallow layer of liquid resting upon the shelf. As the vapour pro-
gressively cools condensation takes place, glycerine with but little water is
deposited on the earlier shelves and on the further shelves mixtures of glycerine
and water in varying proportion having lower and lower boiling points as the exit
end of the condensor is approached. The liquid on the first and hottest shelves
stops the non volatile impurities by washing it out from the vapour as it forces its
way upwards through the perforations. Passing this stage a zone is arrived at
where much glycerine is condensed whilst water and impurities more volatile than
glycerine pass on. Finally at the end of the series steam (with volatile impurities)
blows out from the condensor, for even at the further end a temperature above the
boiling point of water is maintained.
The number of columns in use at a time will be varied according to circumstances.
I draw off purified and concentrated glycerine from one or other of the wells D³
of the shelves D by taps provided for the purpose. Also at the bottom of the first
column I draw off an impure glycerine. I also draw off glycerine from the bottoms
of the succeeding columns.
Volatile organic impurities will be found more or less in the glycerine from the
last column.
I usually employ three columns in series the first column without jackets.
I provide two receivers, one for the glycerine of the purity required, and the
other for the comparatively impure glycerine. I select the part of the apparatus
from which to draw the purified and concentrated glycerine by drawing samples by
the taps D D', I draw the product into the pure glycerine receiver by the draw
off cocks nearest to the still which yields a glycerine coming up to the standard of
purity required.
When the working of the still has been thus adjusted the operation continues
care only being required to maintain the temperatures in the various parts of
the condensor without change. The temperatures are observed by the aid of
thermometers,

page_text: These condensing columns are very usefully employed in the concentration of
weak solutions. In boiling these down in the open or in vacuum much glycerine
is at present lost which is recovered when the boiling is conducted in a close vessel
and the vapour led into a condensing column such as herein described.
The degree of concentration of the product is dependent on the temperature and
pressure maintained in the condensor."
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.) Passing mixed vapours of glycerine and water from a still or boiler into a
condensor provided with perforated shelves on which in consequence of suitable
progressive cooling liquids of different degrees of purity and concentration collect
and can be drawn off whilst steam or water vapour escapes; whereby glycerine is
both concentrated and separated from volatile and non volatile impurities all
substantially as described.
(2.) The generation of mixed vapours in a still or boiler and then passing them
into a condensing column with perforated shelves on which in consequence of
suitable progressive cooling liquids of different degrees of purity and concentration
collect and can be drawn off whilst steam or water vapour escapes; whereby
both concentration and separation of impurities is effected substantially as described.
Dated this 1st day of Anvil 1886
CARPMAEL & Co.,
Agents for the Applicant,