Improvements in the Method of and Apparatus for Distilling Mash for the purpose of Obtaining Highly Concentrated Fusel-oil and Purifiled Alcohol.
Year: 1892

page_text: Date of Application, 7th Oct., 1892-Accepted, 17th Dec., 1892
COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Distilling Mash
for the purpose of Obtaining Highly Concentrated Fusel-oil
and Purifiled Alcohol.
I, ROBERT ILGES, of Cöln-Bayenthal, in the Province of the Rhine, German
Empire, Engineer, do hereby declare the nature of my invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention relates to improvements in distilling mash, and more particularly
to the last treatment of the singlings or phlegm left in the rectificator of a mash
distilling apparatus, the object being to effect a continuous and direct separation of
highly concentrated fusel-oil and purified alcohol.
My invention therefore consists in an operation performed as the last step of the
distillation, and composed of three distinct parts; the first part has for its object
to produce and to maintain in the singlings such a proportion of alcohol as will be
most favorable for the separation of fusel-oil, and I prefer to effect this by keeping
the singlings at the temperature at which the desired proportion of alcohol is
maintained in the liquid; the second part of the process consists in cooling the
boiling singlings, with a view to further reducing their capacity of dissolving fusel-
oil and facilitating the separation of the latter; and lastly, by the third part of my
improved process I effect the continuous removal of the accumulated fusel-oil
without any simultaneous outflow of singlings. My invention also consists in
providing a suitable apparatus for rationally performing my improved process.
In order to fully disclose my invention I will proceed to describe the same
specifically, referring to the accompanying drawings, which represent the apparatus
which I prefer to employ in my improved process, and in which:
Fig. 1, Sheet 1, is a longitudinal sectional elevation of the left part of the
apparatus.
Fig. 2 is a similar view of the temperature-regulator A.
Fig. 3 is a detail cross sectional elevation of the cooler B.
The
Similar parts are designated by similar letters throughout the several figures.
The apparatus consists first of the temperature regulator A, composed of two
horizontal tubes bb, the former, which is preferably made of copper, being
inclosed within the latter, which consists of wrought iron. The tube b connects
with an upright pipe a, fitted with a thermometer a', the tube b' with an upright tube i,
the latter connection being effected by means of an india-rubber tube n.
tube is perfectly closed at both ends. m is the bed-plate to which the tube i is
secured by means of three screws, so as to be easily adjusted to an absolutely
vertical position. Tube i is provided with a widened portion, forming a small
chamber o. Within this upright tube I place a float which is preferably
constituted by a tube of glass containing a small quantity of mercury.
upper end of the float there is secured a string or wire preferably a silk
cord-which is passed over a roll and has a weight fastened to its other end so
as to counterbalance the weight of the float i'. This weight is also connected' to
the handle of a cock, damper, or throttle-valve & adapted to regulate the supply
of water through pipe 1 to the cooler of the dephlegmator.
At the
The communication between the temperature-regulator A and the cooler Bis
effected by the bend c of the tube b, this bend being directed upwards for a purpose
stated hereinafter. The tube is fitted to the socket d, located about at medium
height of the cooler B. The latter is a cast-iron vessel of square cross-section, and
is provided with a series of horizontal tubes a which are inserted in holes made in
opposite walls of the cooler. ppl are water chambers secured to the cooler B, and

page_text: are divided into a series of compartments by horizontal partitions pa placed above
one another in steps in such a manner, that the compartments of each chamber are
separated by partitions placed at a height intermediate between that of the
partitions of the other chamber. Two of these partitions in each chamber,
rands, are however placed at the same height in both chambers, so that the
row of tubes lettered is er tirely disconnected from the other tubes r. It will be
seen by a glance at Fig. 3 that a continuous zig-zag path is created by the tubes x,
the partitions p² of the chambers p and p', and a tube p³ connecting the compartment
situated directly above the upper partition and the andermost compartment of
chamber p. is the inlet-pipe communicating with a water supply pipe or with a
reservoir, and q is the outlet-pipe. It will be noticed that there are no tubes & in
the middle part of the cooler B, where the socket d is fitted to the same.
bottom of the cooler there is a chute from which a pipe e leads to a socket el
terminating tangentially into an annular chamber D, at the top of the distilling
apparatus proper E. g is an upright tube fitted centrally into the top of the cooler B,
the upper end of this tube is inclosed within a cylindrical chamber C and connects
laterally with a loop-pipe h, provided with an outlet socket h¹; the latter ought to
be located considerably above the level y-y of the annular chamber D. The top of
the chamber C has an upright pipe inserted into it centrally, and communicates
thereby with a pipe, fitted to the top of the chamber D.
At the
At
E is a distilling apparatus or tower of the kind employed in the distillation of
alcohol, and is provided with a pipe w inserted tangentially, to supply steam.
the bottom of this apparatus there is a chute from which a pipe f, provided with a
lateral socket, leads into a cooler F constructed with vertical tubes in which water
may enter from below through the socket u and from which it may flow off by the
socket v. A collecting-vessel t connects with the lower part of the cooler F and is
adapted to receive the material having passed through the same.
I wish to have it understood that the described apparatus is combined with a
mash-distilling apparatus of any suitable construction and will be substituted in
such apparatuses for that part in which the phlegm left after the rectification of
the alcohol is subjected to a last distillation. The pipes a and c are connected to the
rectificator.
My improved process is based on the following considerations:
The singlings to be heated according to that process contain alcohol and products
of fermentation of minor volatility, that is to say, fusel-oil; for it may be taken for
granted that the singlings as a rule do not contain highly volatile compounds, and
if they do exceptionally this is due to chemical transformations, especially of the
fusel-oil, occasioned by a defective construction of the distilling apparatus. It
is therefore sufficient, according to the principle of my improved method, to
separate the substances of minor volatility, i.e. the fusel-oil, in order to obtain
pure alcohol.
Now in any distilling apparatus of rational construction, that is to say, effecting
an energetic dephlegmation and rectification, the entire amount of fusel-oil may be
easily separated from the alcohol vapors before the latter are led to the cooler;
this fusel-oil is then condensed and dissolved in highly concentrated singlings. In
order to separate the fusel-oil, its proportion in the singlings must be steadily
increased; this is effected during the passage of the singlings through the rectifi-
cator, by the continuous vaporization, as alcohol is considerably more volatile than
fusel-oil. This favorable effect is however observed only as long as the volume-
trical proportion of alcohol is in excess of about 17 per cent. of the singlings; if the
proportion is less, the fusel-oil becomes of higher volatility than alcohol, and will
not be dissolved in the singlings, as desired, but vaporized in the rectificator. The
conclusion drawn from the above facts is, that the volumetrical proportion of
alcohol should somewhat exceed 17 per cent., and as far as I am able to ascertain
from experiments made hitherto, 21 per cent. appears to be the most favorable
proportion.
The first step of my improved process consists therefore in constantly keeping

page_text: the proportion of alcohol contained in the singlings within the mentioned favorable
limits, and I prefer to effect this in an indirect manner, by keeping the singlings at
the temperature at which the desired proportion of alcohol is maintained in the
liquid.
My improved process is therefore performed as follows:
The boiling singlings left in the rectificator of a mash-distilling apparatus are let
in through pipe a and are caused to flow continuously through the tube b, the bend c,
the socket d, cooler B, pipe e, socket e', distilling tower E, pipe f and socket f1.
Before starting the operation, the tube b¹ is filled with mercury up to the tube b,
and the remaining space with strong alcohol or any other liquid boiling at a low
temperature.
Now the heat of the boiling singlings flowing through tube b will cause the
mercury and alcohol placed in tube b¹ to expand; thus the mercury, the level of
which was initially the same in tube b' and the vertical tube i, will rise in the
latter and fill the small chamber o provided for this purpose. Gradually the
alcohol in tube b' will be heated to its boiling temperature, and the vapors evolved
will cause the mercury to rise in tube i to such a height as to lift the float .
According to the fluctuations in the temperature of the singlings, the float will
oscillate up and down. This movement will be transmitted to the handle k' of the
throttle-valve k by means of the silk cord, and the admission of water through
pipe to the cooler of the dephlegmator will be increased or reduced accordingly
in such a manner as to regulate the temperature of the singlings and to keep it
constantly at the required point. It will be obvious that thereby a constant
proportion of alcohol is maintained simultaneously.
It is desirable to prevent as much as possible the heat of the singlings from being
communicated to the upright tube i, and therefore the connecting tube n is made
of india-rubber or any other good non-conductor of heat.
It will be obvious that the same effect, viz. keeping the temperature of the
singlings at a constant point, may be obtained by regulating the supply of steam or
mash to the mash distilling apparatus. It will be further obvious, that, when
regulating the supply of steam to the mash distilling apparatus, the passage of the
throttle-valve is to be narrowed when the temperature of the singlings increases,
whereas it is to be widened with rising temperature when regulating the supply of
water to the cooler of the dephlegmator. It will be easily understood that the
regulation of the supply of mash to the mash-distilling apparatus may be effected
in an analogous manner.
The singlings, which already contain fusel-oil in a separated state, owing to the
keeping up of a temperature which highly favorizes the evaporation of alcohol, flow
then through the bend c. This bend is directed upwards in order to permit the
unhindered flow of the specifically lighter fusel-oil to the cooler B. If the pipe
were straight, the singlings cooled in the cooler B would partially flow back in the
lower half of this pipe into the temperature-regulator, i.e. into the tube b, whereby
the action of this regulator would be influenced unfavorably. If the bend c were
directed downwards, a large portion of tube b would remain filled with fusel-oil,
whereby the transmission of heat from the singlings to the mercury and alcohol in
tube would be impaired.
The singlings entering the cooler B by the socket d may spread uniformly in the
middle part of the cooler, which is free of tubes, and sinks gradually into the lower
part of the same. During this downward movement, the singlings are cooled by
the water which is made to circulate through the tubes and the compartments of
the chambers p and p'; thereby the remainder of fusel-oil dissolved in the singlings
Now
is separated, and being specifically lighter, rises to the surface of the same.
as the upper layers of the singlings are still warm, the rising globules of fusel-oil
will be partly dissolved, and it is necessary to cool them again energetically in
order to effect their complete separation. For this purpose the cooling water is
caused to enter at the top of the cooler B, as described, so that the upper layers of
the singlings will be cooled most energetically. In order to prevent a mixture

page_text: of this strongly cooled layer with the layer of boiling singlings in the middle of
cooler B, a layer of medium or neutral temperature is created between the same by
placing one row of horizontal tubes x¹, out of the circuit through which water
circulates. It will be seen by reference to Fig. 3 and to the arrows marked
thereon that the particles rising from the hottest (boiling) layer of the singlings
are cooled by the water in several rows of tubes before getting to the neutral
zone at the level of the tubes .c¹.
In consequence of the described arrangement the globules of fusel-oil are fully
separated from the singlings in the upper part of the cooler B and being in a highly
concentrated state rise in the oil-tube y. As the socket h for the outflow of
fusel-oil is located a considerable distance above the highest level to which the
singlings ascend, i.e. the upper termination y-y of the chamber D, it will be
evident that the singlings cannot mingle with the fusel-oil flowing off through the
loop-pipe h¹ into a suitable closed reservoir.
e.
The singlings cooled in the cooler B rise in the pipe and are let into the
chamber D below the line yy, i.e. the level of the liquid, in order to avoid changes
in the pressure exerted on the surface of said liquid. This pressure is obtained by
steam entering the singlings-distilling tower E through the socket, w.
It is of great
importance to constantly produce an equal pressure on the surface of the liquids in
the communicating tubes g B and e D. This pressure is exerted in chamber D
upon the surface of the singlings, and in chamber C upon the surface of the fusel-
oil accumulated in pipe g. The singlings in chamber D are heated directly by the
steam rising in the tower E and indirectly by the heat absorbed and transmitted by
the walls of the tower. In order to prevent the heated singlings from commingling
with the cooled material entering through the socket ', the latter is fitted
tangentially to the chamber D, so that the singlings are brought to move on with
a uniform rotating motion. In the other branch of the communicating, tubes the
same precautions must be taken for insuring a gradual heating' of the cooled
fusel-oil rising in pipe g. The steam and the alcohol vapors proceeding from the
tower E enter into the chamber C through the tubes and 2 and heat the upper
end of the tube g, and consequently the fusel-oil contained in the same, before
coming in direct contact with the said fusel-oil. The condensed steam and vapors
do not mix with the fusel-oil, but flow back to the pipe e through the tube g¹. In
this manner the high concentration of the fusel-oil is preserved.
The singlings flowing into the tower E over the inner rim of chamber D, and
freed from their contents of fusel-oil, as described, are completely freed from the
alcohol which they still contain by the steam admitted through socket w.
The
remaining watery solution is let off through pipe f and socket f¹. The vapors
evolved from this solution, which is in a superheated condition, are led into the
cooler of a singlings testing apparatus to be condensed there. The condensed
liquid flows in a small continuous stream into the collecting-vessel t, where its
contents of alcohol are ascertained by means of an alcoholometer. The cooling
water is caused to circulate from below to above, entering through the socket u,
and flowing off through the socket v. The vapors generated in the tower E, which
are free from fusel-oil, are conveyed to the rectificator of the mash distilling
apparatus through the pipe
By the three steps of my improved process the fusel-oil is separated from the
singlings, as described, and removed from the apparatus, so that the amount of
fusel-oil contained in the rectificator and dephlegmator is reduced, and decom-
positions of these products of fermentation prevented. Thus the ethylic alcohol
contained in the mash is obtained without any admixture of impurities.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
11. As an improvement in the distillation of mash, the herein described process
for separating the fusel-oil from the singlings proceeding from the rectificator of a

page_text: mash distilling apparatus, which consists in keeping the said singlings at a constant
boiling temperature corresponding to a volumetrical proportion of alcohol somewhat
exceeding 17 per cent., for the purpose set forth.
2. As an improvement in the distillation of mash, the herein described process.
for separating the fusel-oil from the singlings proceeding from the rectificator of a
mash distilling apparatus, which consists in keeping the said singlings at a constant
boiling temperature corresponding to a volumetrical proportion of alcohol somewhat
exceeding 17 per cent., and in cooling the singlings hereafter, for the purpose.
set forth.
3. As an improvement in the distillation of mash, the herein described process
for separating the fusel-oil from the singlings proceeding from the rectificator of a
mash distilling apparatus, which consists in keeping the said singlings at a constant
boiling temperature corresponding to a volumetrical proportion of alcohol somewhat
exceeding 17 per cent., and in cooling the singlings hereafter, and in utilizing the
inferior specific weight of the fusel-oil for separating and drawing it off in a.
continuous manner, substantially as and for the purpose described.
4. In an apparatus for treating the singlings in the distillation of mash: the-
temperature-regulator A, consisting of the double tube b b¹, the boiling singlings.
flowing through the inner tube, and the outer. tube being partly filled with mercury
and partly with a liquid boiling at a low temperature, the vapors evolved from this.
liquid being employed for driving the mercury upwards in the upright tube i and
to cause the float to oscillate, and thereby to control and regulate either the
supply of cooling water to the dephlegmator, or of steam or mash to the mash
distilling tower, substantially as described, for the purpose set forth.
5. In an apparatus for treating the singlings in the distillation of mash: the
cooler B, into which the boiling singlings enter in the middle part of the same, the
layers of singlings above and below this middle layer being cooled, and a zone of
neutral temperature being created by placing a row of tubes out of the circuit
through which water circulates; the singlings being caused to flow through this
cooler B after having passed through the temperature-regulator A, substantially
as and for the purpose described.
6. In an apparatus for treating the singlings in the distillation of mash: the
means for continuously discharging highly concentrated fusel-oil from the apparatus,
consisting in gradually warming the fusel-oil in the chamber C and the singlings.
in the chamber D, and discharging the liquid proceeding from the condensation
of vapors in C through the pipe g', substantially as described, for the purpose.
set forth.
Lateo L018 OLD AAV O UcLoner 1892.
Lateo L018 OLD DAY OF Uctober 1892.
ROBERT ILGES,
By Geo. H. Rayner, .
37, Chancery Lane, W.C., Agent for the Applicant..