Improvements in Methods for the Recovery and Utilization of Certain Vaporized Solvents
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Methods for the Recovery and Utilization of
Certain Vaporized Solvents
We JAMES RAYNOR WHITING of 737 Madison Avenue in the City County and
State of New York, Manufacturer, and WILLIAM APPLETON LAWRENCE of 59
Main Street Waterville, in the County of Oneida, and State of New York,
Superintendent, United States of America, 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 :-
Our invention relates to an improvement upon the "Method for the Use and
Recovery of Vaporized Solvents" described in Letters Patent of the United States
of America No. 170,424 granted to us Nov. 23, 1875, and is an improvement
upon all methods heretofore existing and known to us, which is used for the extrac-
tion of the active principles and valuable contents of hops by bringing the hops in
contact with petroleum ether or any of the suitable lighter products of the
destructive distillation of coal or petroleum as solvents, and our invention relates
simply to its use in the process of the extraction of hops, and when employed in
the recovery of the above mentioned solvents.
That the object and usefulness of our invention may more clearly appear it is
necessary to be understood that, in the method of extracting hops, owing to the
great bulk of the leaves of the hops remaining in the extractor, after the extract
has been removed by the use of the above mentioned solvents and the liquid solvents
containing the extract have been drawn off, there remains entangled among the
leaves of the refuse hops a valuable remainder of vaporized solvent; and further-
more it is necessary to be understood that the contact of steam with the extract of
hops, with the resulting continued presence of water in the extract and consequent
oxidation of the essential oil of hops, is very detrimental to the subsequent
preservation, quality and value of the extract.
The object of our invention is, to remove and recover for use, more rapidly and
completely than by any previously existing method, the above mentioned vaporized
solvents remaining in the extractor among the refuse hops, after the solvents
containing the extract have been drawn off, and to accomplish this object by the
use of steam and also to preclude the steam at any and all times from contact with
the extract.
In order to enable a full and clear understanding of our method to be had, we will
first proceed to describe its relation to the preceding method for the extraction of
the hops by reference to the accompanying drawing which is a diagrammatic
representation of an apparatus employed in carrying out our method.
The extractor A, consisting in the prescut case, of a cylindrical vessel of suitable
construction and size is provided interiorly with a suitable cage for containing the
hops. The extractor communicates through the pipe B, with a pipe C. located
In the bottom of
within the evaporating chamber D, which pipe ( is perforated.
the chamber D is arranged a steam coil E, passing through the chamber D and in
position to receive upon the coil the liquid solvent containing the extract as it is
drawn off from the extractor A, through the pipe B and is dropped from the
perforated pipe ('.
The solvents used, and already named, being very volatile, are driven off in the
form of vapor to a condenser of any suitable construction through the pipe a,
condensed and thence conducted to receivers for further use, while the extract of
the hops, being less volatile than the solvent falls to the bottom of the chamber D
whence through the pipe it is drawn off from time to time for u-e.
The extractor A having now been emptied of its liquid solvent, containing the

page_text: extract, into the chamber D, there remains in the extractor A a large mass of the
leaves and woody fibre of the hops and this mass is permeated throughout with a
valuable remainder of vaporized solvent, which at this stage of the process of
extracting hops, we remove and recover for use by our invention. The apparatus
employed for carrying out our method, is as follows :-
A coil condenser F, is connected with the extractor A by the pipe and valve k
as shown. and communicates as shown with a receiver G. The extractor A is
furnished with a steam inlet pipe b. The lower part of the extractor communicates
by means of a valved pipe H, with a force pump M and with the lower part of a
receiver I. The upper part of the receiver (communicates with the upper part
of the receiver I through the valved pipe c. The receivers GI communicate
through the pipes d d' and e with the condenser J, and the condenser J discharges
The
into the condensing coil K, which is contained in the refrigerating casing L.
coil K terminates in an air pocket f provided with an escape valve g. The pipe h
connected with the pocket f leads to the receiver 1.
The receivers G, I, are
provided with liquid gauges i by means of which the level of the liquids and the
position of the dividing line between the water and the solvent may at any time
be seen.
The
Having completed the method of extracting the hops, as already described, to
the point at which the extractor A is discharged of the liquid solvent containing the
extract, and now contains only the great mass of extracted and refuse hops
permeated throughout with a valuable remainder of vaporized solvent, we now carry
out our improved method of removing and recovering this vaporized solvent by
means of our invention as follows:-The valve in the pipe B is closed, thereby
preventing all access of steam to the extract in the evaporating chamber D.
valve in the pipe leading to the condenser F is opened, allowing such portion of
the vaporized solvent in the extractor A as will escape of its own pressure, to pass
into the condenser F and thence in a condensed and liquid form to the receiver G.
After a suitable time being given for the escape of a part of the vaporized solvent
in this manner, the valve k is about nine-tenths closed and superheated steam is
admitted through the pipe b to the extractor and its mass of refuse hops for about
twenty-five minutes. The steam is then shut off, the valve k is fully opened, and in
a short time the voporized solvent is found to be entirely removed from the
extractor A and its mass of refuse extracted hops, and it is ready to be discharged
and recharged with fresh hops and the method repeated.
By the admission, to the condenser, of such portion of the vaporized solvent as
will pass from the extractor into the condenser by the action of its own pressure
and the vacuum caused in the condenser by the condensation of this vapor, the
process is carried out with greater rapidity than by the immediate admission
of steam.
The partial closing of the valve k as described creates a pressure in the extractor,
and the steam is forced by this pressure into the mass of refuse hops and thereby
reaches and renders mobile the vaporized solvent entangled mechanically in the
hops, so that when the valve k is fully opened, a rapid current is produced and the
vaporized solvent speedily removed.
The solvent condensed in the condensing coil F, together with the water
condensed from the steam, is carried to the receiver G. When the receiver G is
nearly filled with the solvent and the water, the valve in the pipe is opened,
allowing the solvent which floats upon the water, to pass by gravity from the
receiver (i into the receiver 1. Any vapor which passes the condensing coil F is
carried by the pipes d d' e to the condenser J, where its temperature is reduced by
water surrounding the condensing coil; it is then conveyed by gravity through the
refrigerating coil K, where it is still further condensed. The air and a very small
portion of the vaporized solvent is allowed to escape from time to time through the
valve while this final portion of the condensed solvent is returned to the receiver
I through the pipe h.
The recovered solvent is drawn from the receiver I for use whenever required,

page_text: by means of the pump M. The water delivered to the receiver G is removed from
time to time through the valve l.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The method, herein described, of recovering the vaporized solvent remaining
in the refuse hops in the extractor after the extract has been drawn off, consisting
in removing and condensing that portion of the vaporized solvent in the extractor
which will escape of its own pressure, then admitting steam into the extractor
among the refuse hops, to thoroughly permeate the hops and drive off the vaporized
solvent mechanically held in the hops, removing and condensing the escaping
vaporized solvent and steam, and finally separating the solvent from the water of
condensation, as specified.
2. The method, herein described, of recovering the vaporized solvent remaining
in the refuse hops in the extractor after the extract has been drawn off, consisting
in removing and condensing that portion of the vaporized solvent in the extractor
which will escape of its own pressure, then admitting steam into the extractor,
retarding the escape of the steam from the extractor for a short time, then allowing
it to escape freely, condensing the escaping steam and vaporized solvent, and finally
separating the solvent from the water of condensation, as set forth.
J. R. WHITING.
W. A. LAWRENCE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.