Improvements in and Apparatus for Separating, by Means of Lightly Compressed Air, Fluid from Solid Substances or Lighter from Heavier Particles of Liquid Bodies.
Year: 1893

page_text: Date of Application, 3rd Jan., 1893-Accepted, 18th Feb., 1893
COMPLETE SPECIFICATION.
Improvements in and Apparatus for Separating, by Means of Lightly
Compressed Air, Fluid from Solid Substances or Lighter from
Heavier Particles of Liquid Bodies.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention (which has been com-
municated to me from abroad by Adolph Bornholdt and Joseph Glatz, Manufacturers
of. 487 Kent Avenue, Brooklyn, State of New York in the United States of
America) 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 reference to the separating or extracting of fluids from solid
organic substances, and the separating of the lighter or the more volatile from the
heavier or less volatile constituents of a liquid. The principle of the invention
consists in the use of air under a high degree of compression in a closed vessel,
heated or not according to the requirements of the case. The invention also relates
to an apparatus or means, which I will term a "pneumatic press," for use in
effecting the operations referred to above, or other like operations.
For the purpose of explaining the principle of this invention I will give several
specific illustrations of its industrial application.
(1.) EXTRACTING LIQUIDS FROM ORGANIC SUBSTANCES.
•
This group comprises a great variety of applications of the invention. The
treatment of the spent mash or refuse from distilleries may be taken as a typical
illustration. This refuse is now, in large measure, wasted for want of an efficient,
economical and unobjectionable method of treatment, though it constitutes or
contains valuable food for fattening cattle. This substance, however, speedily
ferments, and in warm weather becomes offensive and worthless for any purpose.
Moreover the great bulk of the refuse makes it too expensive to transport to any
considerable distance. The present methods of treating this refuse by evaporation,
or by compression in ordinary presses, have not proved satisfactory, and are used
only to a limited extent.
In the ordinary method of expressing the liquids from spent mash by compression,
it is common to employ a press having a disc or platten fitting in a cylinder, which
disc or platten is forced down by a screw, lever or other like means, squeezing the
compressible substance into a smaller and smaller space, the liquid being squeezed
out and flowing through perforations in the walls of the cylinder. The more the
mass is compressed, the greater the force necessary to expel the remaining liquid,
and in consequence fine fibres or particles of solid substances are forced out there-
with. Furthermore it is not possible in any ordinary press to extract the liquid
completely. The interior parts of the compressible mass are never so well dried as
the particles on the surface, partly because the elasticity of the mass opposes and
diminishes the effective pressure, and partly because the outer surfaces become very
hard and compact and so impede the escape of the liquid from within.
According to this invention the air is forced into the vessel containing the spent
mash in direct contact with the said mash the action of the said air being to displace
the liquid particles, forcing these to separate from the solid or fibrous substance,
and to collect in a free space provided in the bottom of the vessel, whence the
liquid can be drawn off at intervals. By this method the substances treated are not
compressed into a contracted space, but remain at the close of the operation in a
loose, disintegrated and dry condition entirely free from all deleterious and
objectionable matters, and in a state suitable for feeding live stock.

page_text: The use of air under high compression in the separation of mixed liquids, upon
lines of segregation determined by their unlike thermometric points of vaporization,
constitutes an important application of this invention.
The ordinary process of distilling, as is well known, is carried on by subjecting
the liquid to be distilled to the action of heat sufficient to vapourize the volatile
constituents thereof, and subsequently collecting and condensing these vapours.
Sometimes the heat is supplied by a current of steam which is caused to pass
through the liquid, thereby agitating the said liquid and facilitating the evolution
and liberation of the gases. It is also common in distillation to apply a suction or
exhaust pump to the still for the purpose of creating a partial vacuum therein, and
producing a more rapid discharge of the vapour as they are formed. My foreign
correspondents have found however, that when a vacuum is so used, the rarification
of the atmosphere in the still causes a lowering of the temperature and a consequent
waste of heat.
The new treatment consists in the subjection of the liquids to the action of air
under a high pressure in a closed vessel having a valve to regulate the degree of
pressure, contrary to the more common practice, which aims to relieve the liquid to
be vapourized from ordinary atmospherie pressure, whereby volatization is
ordinarily promoted owing to the reduction of the boiling point. The forcing of
air, (preferably heated,) into the mass of liquid while under pressure, brings a large
volume of air into intimate contact with the more volatile portions, so that, when
the pressure is suddenly removed by allowing the compressed fluid to escape into a
condenser, the spring towards recovery of volume is proportionally energetic, and it
is the more volatile portions that rebound more promptly, and these not finding
sufficient heat to give normal volume to their vapourous form, readily condense,
owing to the falling temperature in the condenser, thus doing away with the
necessity for artificial cooling means. In this there is great economy, combined
with efficiency. while even less initial heat for vapourization is required than before.
No danger of burning the liquor is incurred, and a purer distillate, and greater in

page_text: quantity may be obtained, than where a steam coil or a direct fire under the still
is used.
In the ordinary process it requires a temperature of about 150° Fahrenheit to
distil alcohol. According to this invention the crude spirit is placed in a suitable
tank or vessel adapted to withstand high internal pressure and provided with an
adjustable valve which controls the outlet or escape pipe, and which can be set
to maintain the desired pressure in the tank. Air is then forced in up to a
pressure of say 300 lbs. The liquid may be warmed by preheating the air, or
by direct heat of a furnace or otherwise, to a temperature of about 100° Fahrenheit.
Under these conditions, the air passing through the liquid, becomes saturated or
impregnated with the vapours thereof, acting therein like a solvent. As the
pressure increases the air passes more slowly through the liquid body, remaining
for a considerable time in contact therewith and thus becoming completely charged
or saturated.
Thus the separation of the lighter from the heavier constituents of the liquid
is effected at a temperature much lower than that ordinarily required, and economy
of fuel, is one result. It also follows that condensation of the vapours is accom-
plished more easily and expeditiously than in ordinary processes. When by raising
the pressure above the limit to which the valve is adjusted the air commingled
or saturated with vapours, is allowed to escape into the condensing vessel, the
sudden expansion causes a fall of temperature which aids the condensation of
the vapours to such an extent that but little water or other cooling medium for
condensing is required.
The invention is not of course limited to any particular degrees of temperature
or pressure, these being variable within certain limits, and must be regulated to
suit the particular liquid under treatment.
The principle of this part of the invention differs radically from the well known
process of ageing liquor by forcing currents of warm air through the said liquor.
In such case, the only function of the pressure is to impel the current of air, which
takes up the more volatile portions of the liquor.
In the process according to this invention the pressure is accumulated in the
vessel containing the liquid until it reaches a high degree and then acts first by
compression and then by sudden expansion, in a manner essentially novel.
The operations herein referred to and others of like nature, are not dependent
upon any particular form of apparatus but this invention includes an apparatus or
press adapted to work upon the principle of this invention.
The improved press comprises as its essential elements a pump or air compressor
adapted to furnish the degree of compression required (which for some purposes
may advantageously be as high as 1000 pounds, or even more) and a compression
chamber capable of withstanding a high internal pressure and having an inner
perforated cylinder through which the air can find ready access to every part of
the contents of the
press.
Such an apparatus is illustrated in the accompanying drawings in which
Figure 1, is an elevation partly in section, of an apparatus constructed in
accordance with the invention, and Figure 2, is a cross-section of the press proper.
The said press consists of a strong tank or vessel A, adapted to withstand a high
pressure. Within this vessel is a perforated cylinder B, somewhat smaller than
the interior diameter of the vessel A, so that an annular space is formed between
them.
The press-is supported upon a foundation of masonry C, which encloses an
air-storage and heating chamber D, beneath which is the grate E. F represents
an air pump having sufficient power to supply the necessary compression. The
pipe e leads from the pump into the chamber D, and the pipe f leads from the
chamber D to the lower part of the press, between the inner and outer cylinders A
and B. The pipefis provided with a check valve g.
G represents a purifier of any suitable kind through which the air is drawn by
the pump F.

page_text: The perforated cylinder B.of the press may contain a series of perforated
shelves I, of which there may be any desired number. Beneath each shelf is a drip
pan or tray i which catches the liquid flowing through the perforations of the shelf,
and conducts it to one side of the cylinder.
K, K represent man-hole openings for giving access to the interior of the
cylinders to charge them or remove the residues. L is a receptacle for the liquids
which are drawn off by the pipe 7 provided with a cock . M, M are the air and
vapour discharge pipes each provided with an adjustable pressure retaining
valve m, which can be regulated by the screw n to maintain any desired pressure
in the cylinders A, B.
The substances which are to be subjected to compression are introduced through
the man-hole openings into the inner cylinder, the pressure valves set to the proper
point and the outer cylinder closed. The pump is then put into operation and air
forced into the storage chamber D, and thence into vessel A. If the operation
requires warm air (which is preferable in some cases) a fire is maintained under
the chamber D. The great compression of the air itself generates heat, so that in
some operations the preheating of the air is not necessary. The air entering
vessel A is distributed through the whole mass contained in cylinder B exerting
equal pressure upon all parts thereof, so that the liquids fluids or juices are
extracted with uniformity.
When the apparatus is used for separating liquids, the perforated inner cylinder
may be dispensed with, though it is desirable to use a perforated diaphragm to
distribute the air, in a manner well known.
It will be obvious that other modifications may be made in the details of the
construction without departing from the spirit of the invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described process of extracting or separating the fluid con-
stitutents from vegetable, or other organic substances, or the lighter from the
heavier constitutents of liquid bodies, by subjecting the same to the direct action
of air under a high and controllable pressure in a closed vessel and maintaining
such pressure until the desired separation is effected substantially as hereinbefore
:set forth.
2. The herein described process of separating the lighter from the heavier
constitutents of liquid bodies by forcing warm air under high pressure, into
intimate contact with such bodies in a closed vessel provided with a regulating
valve, and suddenly expanding the compressed fluid in a chamber of low pressure,
thereby condensing the vapours and separating them from the air substantially
as hereinbefore set forth.
3. The separating apparatus or pneumatic press constructed and operating
substantially as hereinbefore described and as illustrated in the accompanying
.drawings.
Dated this 3rd day of January 1893.