Improvements relating to the Distillation, Evaporation, and Extraction of Liquids.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements relating to the Distillation, Evaporation, and Extraction
of Liquids.
I, EDWARD THEISEN, of 9, Werderstrasse, Baden-Baden, in the Empire of
Germany, Engineer, do hereby declare the nature of this invention to be as
follows:-
In the distillation and evaporation of many liquids it is of especial advantage
to carry off with all possible speed the vapours from the liquid heated from the
outside. For this purpose it is especially advantageous to use centrifugal force;
but in this case the opposite effect is to be produced to that of the process already
proposed by the inventor, of allowing liquids and gases or vapours to work alter-
nately. This prior process consists in conducting the liquid along the inner side
of a cone or cylinder casing in a thin layer and introducing gas or steam in the
form of a centrifugal current under pressure against the layer lying upon the
casing.
The process used for this new purpose consists essentially in conducting the
liquid to be distilled or evaporated compulsorily in rapid motion by centrifugal
gas pressure in a thin layer over the inner side of a closed, conical or cylindrical
evaporating apparatus heated from the outside which is provided only with out-
lets and inlets for the liquid and an outlet for the gas produced, and in evenly
taking off in layers and expelling the gases produced by heating from the circu-
lating liquid and in doing so quickly so as to prevent so far as possible all further
contact of the gases produced in the apparatus with the liquid, in order that a
constant space for gas or steam is obtained in the apparatus in the highest
possible degree.
In this it is of great advantage to conduct the vapours with all possible speed
from the place where they are produced away from the outwardly heated fluid,
so that the gases from the layer of liquid nearest to the heating surface are not
compelled to pass over the next layer. This was hitherto only possible to a very
limited extent in the case of highly concentrated, viscid substances, because with
these the substance could only be kept through the motion caused by boiling in
sufficiently energetic circulation to prevent its burning the heating surface or
sticking thereto. For the purpose of assisting the circulation suitable stirrers
were employed which were inserted in the liquid.
The bubbling produced by the boiling causes various disadvantages with many
liquids, for example in tar distillation, in the concentration of many lyes, as
strontium lyes and the like, in that a frothing over and through the explosion of
the bubbles, a harmful splitting of non-gaseous bodies arises and the vapours are
thereby rendered impure.
The present process obviates these disadvantages by the employment of a

page_text: centrifugal gas apparatus which works so closely over the layer of liquid, without
actually touching it, that not only is the liquid set in rapid motion, but at boiling
temperature also a rapid motion is produced in liquids through the skimming
action of the centrifugal apparatus over them even in those in so high a degree
of concentration that they are already in the form of pulp and prevents a burning
or caking on the heating surface. At the same time bubbling is rendered im-
possible in the thin, rapidly moving 'layer, in consequence of the taking off in
layers of the gases which is effected by this process, so that a current of gas as
pure as possible leaves the apparatus under the gas pressure produced at the same
time by the centrifugal apparatus.
1
Through the compulsory rapid and, even, motion of the thin layer of liquid
on the heating surface and through the compulsory taking off in layers of the
gases and vapours produced by the centrifugal gas apparatus a very intense
heating of the surface of the apparatus is allowable without any fear of
injuring even liquids difficult of treatment through too high a tem-
perature. It is also of importance that in the evaporation or distillation of
sensitive or easily influenced liquids the temperature should be capable
of being easily regulated, and thus it is of especial value for fractional distillation.
Furthermore it is the case that through the continual circulation of an extremely
thin layer only a very small quantity of the liquid in question is in the apparatus.
The apparatus serving for this purpose consist of the outwardly heated, conical
or cylindrical stationary surface of a container with the inlet and the outlet for
the liquid, as well as the outlet for the gases or vapours produced and of a centri-
fugal apparatus within this container. This centrifugal apparatus is provided
on the outside with channels for taking up and wings for taking off in layers
and quickly carrying off the vapours produced, but serves at the same time for
the purpose of dividing the liquid conducted to the upper part of the casing,
and of putting it in rapid motion on. the casing, for the purpose of obtaining,
through the rapid flow of the layer of liquid thus produced, an evenly covered
heating surface and at the same time a high concentration of the liquid. A cone
fixed in the body of the centrifugal apparatus serves the purpose of obtaining a
continuous concentration on the heating surface of the liquid in the apparatus,
and also the purpose of taking up the liquid which reaches the bottom of the
apparatus and conducting it again to the upper part of the heating surface. At the
same time it serves to mix the fresh liquid introduced from below, this being
introduced through the inlet, mixes with the liquid flowing over the bottom wall
of the apparatus which has already been subjected to the process and driven up-
wards with this on to the surface of the cone, becomes better mixed and encounters
a change of temperature before they are conducted together on to the heating sur-
face. The liquid can, however, be admitted through an inlet ajutage which may
be fixed on the upper end of the surface of the apparatus.
One form of apparatus comprises a heating surface greatly widened at the top,
and a centrifugal gas apparatus with conical and at the same time slantingly
shaped wings taking off in layers, the cap of which is provided on the left hand
side with a double casing, for the purpose of allowing the current of gas pro-
duced by the pressure of the wings to escape without any hindrance between the
cap and this casing; while on the right hand side is arranged the gas outlet for
the purpose of utilising the upper part of the wings for taking off in layers as an
exhauster on the gas current and so obtaining a space for gas in the apparatus.
In another form of apparatus a cylindrical body is provided, heated externally
on the one side by the gases of combustion and on the other by the steam casing,
and a gas taking-off-in-layers centrifugal with double walls. The gases are
taken off in layers through openings in the outer casing, so as to be conducted
further by the slantingly arranged pressure wings which are between the two
centrifugal casings, these are arranged at equal distances from the inlet openings,
and form at the same time an air tight partition for the next chamber for taking

page_text: off in layers, so that the gases are collected here and conducted upwards to the
.outside.
On the upper part of the heating surface or surface for taking off in layers is
fixed a plate to prevent gas from flowing out at this point so that the gases pro-
duced, which are separated from the liquid are forced out exclusively through the
chambers for taking off in layers.
רד
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Distillation, Evaporation and Extraction
of Liquids.
I, EDWARD THEISEN, of 9, Werderstrasse, Baden-Baden, in the Empire of
Germany, Engineer, 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:-
In distilling or evaporating certain liquids a material advantage is derived
from such arrangements which will enable the vapours to be as rapidly as possible
conducted away from the liquid which is being heated externally.
Hitherto, however, distilling apparatus of this class have been unprovided with
any means for carrying away in a suitable manner the vapour rising from the
liquid surface; in such a manner, in fact, as to bring about a reaction favourable
to the evaporating process itself. It is such a method of eduction of vapours
that forms the subject of the present invention.
"6
The purpose of the invention is accomplished by causing certain devices of suit-
able construction to move (or "sweep") over the liquid surface, in immediate
proximity thereto, at a comparatively high rate of speed, so that they will carry
away with them the vapours existing above the liquid surface, that is to say
remove them from the spot where they are evolved, and, as it were, peel" from
the surface of the liquid. By this "peeling" the same effect is attained as before,
but in a degree which has not hitherto been attained. The evaporation becomes
both more active and more uniform or in other words more homogeneous, the
resulting products being of a like nature throughout. Now until the present time
no existing arrangement has produced this effect, nor has any process been devised
tending to accomplish this or a similar result.
What we have to deal with here, in addition to this novel and effective feature,
-the "peeling off" of the vapours, -is the fact that this feature is utilized in
conjunction with a process described in my prior Patents No. 16726 A.D. 1892
and No. 23595 A.D. 1896, or rather, with a specially developed form of that pro-
cess. I discovered some time back that by various means a thin liquid layer may
be maintained by centrifugal force upon a cylinder or conical case and be caused
to co-operate with a current of gas also subjected to centrifugal action, though
generally flowing in the opposite direction, so that there takes place a close mutual
reaction between the two.
Now whereas, hitherto, centrifugal force has been applied to liquids by revolving
the surface over which a liquid current flows, the application of centrifugal force
in accordance with this invention is to be effected by a gaseous current, which is
projected, or forced, on to the liquid. Accordingly the liquid is carried away,
along with the gas, owing to the friction between its surface and the circling

page_text: volume of gas and slides along the surface, overcoming a proportionate amount
of friction; while in the old construction such liquid surface itsen was set in
rotary motion.
Now in the old construction, the difference between the speeds of motion of the
liquid and gas, respectively, was obtained by the casing and the blades or vanes
of the fan, revolving at unequal speeds and in different directions, the difference
of speed is, in this arrangement, the result of the friction of the liquid against the
casing in consequence of which friction such liquid lags behind the gases in
centrifugal motion. The pressure here produced must obviously be far more
considerable than in the old constructions.
"
This method of producing motion is of great importance to the success of the
liquid-evaporating process, if taken in conjunction with the above mentioned
peeling off" of the vapours, as, by such means, there develops an increased pres-
sure in front of the knife-blades, serving as fans while in the rear of such blades
or fans, the pressure is reduced; and it is precisely this constant alternation that
is calculated to promote the desired evaporation.
The process adopted for producing this novel effect mainly consists in rapidly
moving the liquid to be distilled, or to be evaporated, in the condition of a thin
layer, over the inside of a closed evaporating body of conical or cylindrical shape,
heated externally and only provided with inlets and outlets for the liquid and
one outlet for the gases evolved: such motion being imparted to it by gas
under pressure, moved by centrifugal force; and further in peeling off" as
it were the gases, generated from such circulating liquid by the heat and
rapidly removing them, so as to prevent as far as possible any further con-
tact of the gases, once evolved in the apparatus, with the liquid whence they
arise; so that what may be described as a constant steam or vapour vacuum is
maintained in the apparatus at the highest attainable degree of completeness.
It is particularly advantageous to conduct the vapours away from the spot
where they are evolved from the liquid,-which is being heated externally,-
as rapidly as possible, in order that the gases should be compelled to pass off
from the liquid layer situated next to the heating surface. This has hitherto
been feasible but to a comparatively limited extent where highly concentrated,
thick or semi-liquid substances had to be dealt with, as these could only be caused
to circulate (or gyrate) as required, by the agitation produced by boiling, and
thereby prevented from burning on the heating surface, or setting thereon. This
object was accomplished by stirring devices which were immersed in the liquid
and which kept up the circulation.
The formation of bubbles due to boiling, moreover, in the case of certain
liquids as in the distillation of tar, the concentration of certain lyes, such as
strontia lye, and the like, is attended with various disadvantages, as the liquid
is apt to froth or boil over, while owing to the bursting of the gas bubbles, non-
gaseous bodies are frequently carried away with the gas vapours the purity of
which is in consequence detrimentally affected.
These disadvantages are obviated by the present process.
Owing to the compulsorily active and uniform motion of the thin liquid layer
upon the heating surface, and to the--likewise compulsory--" peeling off" of
the gases aud vapours evolved, effected by the centrifugal gas machine (or gas
turbine), the surface of the apparatus may be highly heated without any fear
of impairing the quality of even very delicate or sensitive liquids by too high
a temperature. But then, this result is certainly dependent upon the important
condition that where such sensitive or readily changeable liquids have to be
evaporated or distilled, the apparatus should be fitted with means enabling its
temperature to be controlled and regulated with ease, if this condition be ful-
filled, the apparatus will prove particularly valuable in fractional distillation.
Besides owing to the continuous circulation of a very thin layer or sheet of
liquid, only a very small quantity of the liquid in question is contained in the
apparatus.

page_text: The apparatus for carrying out this process consists of a conical or cylindrical
stationary surface, heated from outside, and fitted with an inlet tube jet or nozzle
and an outlet nozzle for the liquid; also with a gas-outlet-nozzle for the gases or
vapours as they evolved; the apparatus further comprises a centrifugal
machine (or turbine) arranged within the chamber thus constructed. This centri-
fugal device is provided externally with passages or ports for the reception of the
vapours evolved, and with wings (vanes or blades) for the removal or peeling
off" of such vapours, and also for quickly carrying them away; while at the same
time such device serves to divide or distribute the liquid conducted on to the
upper part of the casing, and to set it in rapid motion, so that, by the resulting
rapid circulation of the liquid layer, the heating surface is uniformly covered
and also a high degree of concentration attained in the liquid. In order to obtain
a permanent concentration of the liquid contained in the apparatus, upon the
heating surface, there is built into the body of the turbine a raising cone whose
object it is to take up the liquid which is at the bottom and to re-conduct it
through the apertures on to the top of the heating surface; the said cone at the
same time serving as a mixer of the fresh supplies of liquid admitted below; such
liquid being conducted to it through the inlet nozzle or jet; mixing with the liquid
running over the edge of the bottom surface and already undergoing the dis-
tilling or evaporating process; and being driven upwards, along the cone-surface,
together with this last-mentioned liquid; so that still a better mixture and an ex-
change of heat takes place between the liquids before they are jointly conducted
on to the heating surface. The liquid may, however, if preferred, be admitted
through an inlet nozzle or jet provided at the upper end of the surface of the
apparatus.
Referring to the accompanying drawings
Figure 1 is a vertical section.
Figures 2, 3 4 and 5 shew several forms of blade ports (passages or channels)
arranged at an angle or obliquely.
Figure 6 is a modified form of my invention, and
Figures 7, 8 and 9 are details to be hereinafter referred to.
Figure 1 shows an apparatus with a heating surface a considerably enlarged
towards the top and a "gas turbine" consisting of a raising cone H with "peel-
ing" blades i arranged conically and obliquely, the cup, hood or dome g of said
apparatus being provided internally, on the left-hand side, with a double casing f, so
as to enable the gas current produced by the pressure of the said blades to issue un-
impeded between the dome g and the said casing; while on the right the gas out-
let nozzel is arranged thus enabling the upper parts of the "peeling" blades i
to act upon the gas current as an exhaust fan and thereby to maintain a constant
gaseous rarefaction in the apparatus.
66
Figures 2, 3, 4 and 5 show several forms of blade-ports (passages or channels) h
arranged at an angle or obliquely, such passages h being formed by the blades i.
Figure 6 represents a cylindrical body, heated externally, on one side, by the
furnace gases, and on the other side, by a steam jacket; also a double-walled
gas turbine. The gases are peeled off" through the apertures m in the outer
casing, Figures 7, 8 and 9, for the purpose of being conducted further away by
the pressure blades or vanes i placed at an angle between the two turbine-casings;
which vanes or blades are arranged at uniform distances from the inlet apertures m
and at the same time form a tight cut off from the adjoining "peeling off"
chamber; so that the gases are here collected and carried upwards to be dis-
charged.
To the upper part of the heating or peeling off surface a a cut off plate / can
be secured, so as to be enabled to prevent the gases from flowing out through
the upper gas outlet d; with the result that the gases evolved are ultimately forced
out through the "peeling off" chambers or channels and through the gas-
outlet on the right, separately from the liquid.
In both arrangements, Figure 1 and Figure 6, the liquid enters through the

page_text: nozzle b. This nozzle is provided in the partition S, secured to the bottom of the
apparatus, so that the liquid freshly admitted may be conducted to the raising
cone H, this cone H, acting by centrifugal force, the liquid is raised and, through
holes discharged on to the heated surface a. Through the air pressure, which
the blades i exert upon the surface a, owing to their centrifugal motion, the liquid
is, in spiral convolutions and in the form of thin layers, carried downwards over
the heating surface a, when either of two things happen; if the discharge cock
fitted to the outlet jet c is closed, this liquid will pass over the partitions S, and,
being drawn up by the raising cone, will resume the same circulating course as
before; or, if the cock of the said jet e is open, it will leave the apparatus.
The vapours produced, and the gases evolved, by the action of the heated
surface a are, so to speak, peeled off, by means of the oblique blades from the thin
layer of liquid heated by the surface a, and are conducted by such blades to the
upper or right hand gas outlet, and may be used, if desired, for heating other
vaporisers or the like..
The course followed by the liquid, as well as by the gas or vapour evolved (or
extracted by evolution) is indicated in Figures 1 and 6 of the drawings by lines
of arrows without vanes, and of arrows with vanes respectively.
I would further remark that herein the expression "extraction of liquids
must be understood to mean the evolution or liberation of gases or vapours con-
tained or dissolved in the liquids to be treated. The present process may be
employed for instance for the distillation of tar or oil, for the liberation or extrac-
tion of ammonia, or of benzole or the like, from liquids which have been previously
employed for absorbing these gases or volatile substances. By means of the
present process these gases or volatile substances are liberated by warming or
heating such liquids introduced into an apparatus such as described, whereby
such proportion of the liquid is evaporated as corresponds to the temperature to
be attained in view of the liberation or extraction, c.g. of the ammonia from
the absorbing liquid, whilst the other part of the liquid, which has undergone the
process of extraction can flow off.
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. A distilling, evaporating, extracting or like process, the main feature of
which is that the vapours generated from a thin liquid layer in a heated cone,
preferably by subjecting the same to centrifugal action, are lifted off by a knife-
blade, the edge whereof is situated close above the surface, so as to sweep it, and
are carried away through a suitable channel immediately adjoining such knife
blade, whereby pure vapours are obtained and the production of gas promoted.
2. The process as set forth in the 1st Claim the main feature of which is that
the liquid, owing to the pressure of the vapours subjected to centrifugal action
upon its surface, is itself set in a spiral circling motion and is spread over the
surface of a casing or jacket in a thin layer.
3. A special form of the process referred to in the 1st Claim, whereby a gas
vacuum is obtained in the channels situated behind the knife-edges, preferably
by centrifugal action or condensation; whereby the discharge (or exhaustion) of
the vapours is promoted.
4. The special construction of annaratus for carrying out the process referred
to in the 1st and 2nd Claims, the main feature of which is the provision of
incl ned knife blades upon the outside of a revolving cone, which blades extend
nearly to the surface of a stationary cone surrounding the said revolving cone.
5. A special form of apparatus for carrying out the subject of the 3rd Claim,
wherein the liquid is admitted at the base of the inner cone, flowing over the inner
surface thereof, so that the liquid is subjected to a preparatory heating as it

page_text: rises, prior to passing from the upper edge of the cone on to the surface of the
outer cone.
Dated this 10th day of February 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.