1. business and industrial
2. energy
3. oil

June 6, .1950
‘
G. N. HARcoUR-r
2,510,221
APPARATUS AND METHOD Fox soLvENT ExTRAcTIoN
Filed Oct. 18, 1943
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June 6, 1950
G. N. HARcoURT
2,510,221
APPARATUS AND METHOD FOR SOLVENT EXTRACTION
Filed Oct. 18, 1943
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APPARATUS AND METHOD FOR SOLVENT EXTRACTION
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APPARATUS AND METHOD FOR SOLVENT EXTRACTION
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2,510,221
Patented June 6, 1950
UNI-TED sTATl-:s PATENT ori-'lcs
2,510.221‘
APPARATUS AND METHOD FOR SOLVENT Y
`
E_XTRACTIQN
'
Guy N. `Harcourt, Bufalo, N. Y., assignor, by
mesno assignments, to Blaw-Knox Company,
Pittsburgh, Pa., a corporation of New Jersey
Application October 18, 1943, Serial No. 506,679
s claims.
.
1
(ci. zs-zro)
by providing. on the screw shaft, vradial arms
which are intended to stir the mass of the solids
in the zones between the screw elements. These
are unsatisfactory for the reasons that`the stir
This invention relates to solvent extraction and
particularly to the treatment of solids> with a
suitable solvent, for the Purpose of extracting
from the solids a component or principle whose
removal from the solids is desirable.
'
2
'
.
YSolvent extraction
are particularly
useful, for example, in connection with the ex
traction of oils, fats and waxes from vegetable
seeds, leaves. roots or tubers, in the extraction of
calïeine from coffee beans, and theobromine from 10
ring arms move only when >the screw moves and
at the same speed as the screw. »and therefore.-
they are limited in effectiveness to provide the
necessary agitation which will prevent channel
ing or uneven solvent ñow,_»and there is consid
erable packing at the periphery of the screw at
cocoa beans, in the extraction of oil from soyabeans, and in the extraction of sugar from beets,
and in the extraction of tannins or dyes from-
It is also important that all the solvent be used
as uniformly as possible. in order that the re
wood or bark.
sultant solution may be as concentrated with ex
the different screw sections.
'
Continuously operating extraction apparatus 15 tract as possible. Where the solids to be treated
for oil bearing seeds, nuts, beans and other solids
are of substantialsize, such as coffee beans, it
heretofore used has not been satisfactory, in that
may not be practical to grind the beans. for the
there is considerable ineiliciency in the extrac
reason that after extraction, the beans must be
tion. Where there has been little o_r no agita
roasted. Particularly with objects of such size.
tion oi! the material during the treatment by the 20 the extraction from the cells of the bean or other
solvent, the solvent tends to flow through the
solid is relatively slow, depending upon the rate
path of least resistance, and does not come in
of diffusion of the solute from the.interior of the
contact sumciently and uniformly with all parts
bean or other solid to the exterior.
ofthesolidmaterial. Thisresultsinalossof
The solvent is generally understood to form
thecomponenttoberemovemwhichremainsin 25 a stagnant iilm on the exterior `surface of the
. the residue, the use of excessive amounts of the
bean or solid being treated, which interferes with
solvent -which dilutes the extract, and an un
the rate oi movement of the solvent bearing the
even extraction. In other words. where the ñow
extract from the interior of the bean or obiect.
of solvent through the mass is uneven, the ex
but by reducing the thickness of this exteriorñlm.
traction varies in accordance with this uneven 30 the rate of extraction can be materially increased.
ness. Therefore, there is danger either that some
1t is important, therefore, to obtain as far as pos
ofthesolidswillbesubjectedtoanunnecessarily
sible, a. maximum and uniform movement of the
longtreatmentorthatsomeofthesolidswillnot stream of solvent over the surface of the solid
have all of the extractable component removed.
material or objects in order to reduce the'thick
In view of such unevenness, it has been considered
ness or stagnant nim on such material. This
either that the length of the extractor must be
stagnant iilm is generally assumed to exist in
increased or that the rate of how of the mate
most diiîusional processes in which the extrac
rial must be reduced, which results in a reduction
of the capacity of the extractor with a corre
tion or' an active principle from a solid mate
sponding
rial Isobtained by means of a solvent. Where
Extractors utilizing screws to move the solids
through the extraction chamber have a tendency
to move the solids toward the periphery of the
screw, thereby packing the material or solids 45
rate of progress through the solvent, or of the
solvent through the mass of objects or solids.
cannot be too rapid, since the rate of diffusion
and consequently of extraction of such larger
ooj ects is necessarily slow.
An object of this invention is to improve the
apparatus used forthe solvent extraction of de
in the amount vrequired for in 40 the objects are of relatively substantial size, their
vestment in equipment.
around the periphery of the screwfwhich makes _
it diiiicult for the'solvent to flow through that
partofthemassofsolids,andtendstoleavean
' open channel near theshaft or axis of the screw
through which part of the solvent passes with
insufiìcient contact with the solids. Eiîorts have
beenmsdetoeliminatetheunevennessofex
traction by providing screw elements in the
chamberonlyatintervalasothattherewillbe
sired components from solid particles; with which
greater uniformity in the extent of extraction is
obtained; with which maximum possible extrac
tion is obtained; which will have al1 of the advan
tages of the continuous extraction system and a
minimum of its disadvantages; with which the
less packing at the periphery of the screw, and 55 amount of solvent required for extraction is a
- etmaal
3
4
minimum, and which will be relatively simple.
practical and inexpensive.
Another object of the invention is to provide
relative movements of the conveyor and the stir
ring arms, with which there will be no increments v
of movement of the conveyor while the stirring
arms are in positions in which they may collide
with the vanes of the conveyor during one of
the increments of movement.
an improved solvent extraction apparatus with
which the eiîect of channeling of the solvent in
the mass under treatment will be substantially
prevented; which will be equally eiîective in the
solvent extraction treatment of seeds, beans and
Referring ñrst particularly to Figs. 1 and 2, the
illustrated example of apparatus forming the ex
nuts and chips that contain either a large or a.
traction system will ñrst be described.
In this
small amount of extractive principle; with which 10 embodiment of the invention, the extraction
the solvent will be largely recovered for further
chamber is provided in a housing l having a
use; and which may be used for the treatment of
hopper inlet 2 by which the solids to be treated
materials that are heavier or lighter than the
for solvent extraction, such as beans, seeds or
solvents.
.
nuts, for example, are fed into one end of the
Another object of the invention is to provide an
extraction apparatus, the solids passing down
improved continuous method of solvent extrac
wardly through a conduit 3 into the extraction
tion, with which a. maximum amount of solvent
chamber, as will be explained more fully herein
may be recovered for use in treating further
after. The solids, after passing through the low
solids; which will require a minimum of appa
er part'of the housing l, which part may be called
ratus; which will produce a highly concentrated
“the extraction chamber” >are discharged at the
and relatively pure extract; which will require
opposite end of the housing into a chute 4, Fig. 2,
a minimum of supervision, and which will be
4where the solids then pass to the lower end of
particularly simple, effective and inexpensive.
an upright steamer 5 which, at its upper end.
Another object of the invention is to provide a
discharges into a conduit 6 leading to one end
method of removing part of the solvent from the
of the upper section of a two section drier 1.
residue by a current of hot gas or vapor. such as
The upper section of the drier, at the end oppo
steam or hot air, for example, to reduce the load
site from the connection to the conduit 6, dis
on the dryer.
charges the solids into a conduit 8 which delivers
Other objects and advantages will be apparent
them to the adjacent end of another or lower
from the following description of one embodi 30 section 9 of the drier. The solids are discharged
ment of the invention, and the novel features
from the opposite end of the section 9 into a
will be particularly pointed out hereinafter in
conduit I0 which delivers the dried solids to a.
connection with the appended claims.
conveyor seal Il, and the latter discharges the
In the accompanying drawings:
solids through an overñow hopper l2.
Fig. 1 is a schematic diagram of the major
Fresh solvent in liquid form may be stored in
part of a system for the continuous solvent ex
a tank I3, Fig. 1, and conveyed through a pipe I4
traction treatment of solids in accordance with
controlled by a valve l5 to a work tank IB, Where
this invention;
it
is mixed with previously used, recovered sol
Fig. 2 is a diagram of part of the extraction
and the mixture thereof is then delivered
apparatus and of the steamer and drier, also con 40 vent,
through a pipe H under the action of a pump I8
structed and arranged in accordance with this
to a pipe I9 leading to a preheater 2D, where the
invention;
solvent is heated, if desired. The heated solvent
Fig. 3 is a longitudinal, sectional elevation
then passes through a pipe 2l to the solids dis
through one end portion of the housing in which
charge end of the housing l where the solvent is
the treatment of the solids with thesolvent is 45
delivered
into the extraction chamber formed in
carried on, and which may, for convenience, be
the liquid-tight, lower zone of the housing. The
referred to as having an extraction chamber.
solventv passes through the lower part of this
Fig. 4 is a similar sectional elevation of the
housing in a direction generally counter to the
other end portion of the same apparatus;
Fig. 5 is a transverse, sectional elevation of the 50 movement of solids under treatment in that hous
ing, and is then removed-from the opposite end
same, the section being taken approximately
of the housing by a. pipe 22 which leads to a
along the line 5_5, Fig. 4;
miscella storage tank 23. The entrance opening
Fig. 6 is a sectional elevation of the lower part
into the pipe 22 is protected by a screen, see
of Fig. 5, with the stirring arms in diiîerent
`
operative positions, such as those occupied dur 55 Fig. 3.
From this storage tank 23, the miscella, which
ing the increment oi movement of the solids un
is a mixture of the solvent and the extract or
der treatment;
principle carried thereby, is withdrawn through
Fig. 7 is a sectional elevation through a portion
' a pipe 24, Fig. 1, by a pump 25 and passed through
of the apparatus for driving the stirring arms,
the section being taken approximately along the 60 a ñlter 26 in which any ñnely divided solids which
may be carried in suspension in the miscella are
line '1_-1, Fig. 8;
removed. The solvent with the liquid extract or
Fig. 8 is a longitudinal, sectional elevation
principle carried thereby is then conducted from
through a part of the support for the stirrer de
this ñlter by a pipe 21 to a storage tank 28, and
vice;
Fig. 9 is a longitudinal, sectional elevation 65 this mixture is then withdrawn from that tank
through a pipe 29 by a pump 30, which delivers
through hydraulic operating mechanism for the
endless conveyor, by which the solids are moved
it through a pipe 3| to one end of a preheater 32.
slowly, by increments of movement, through the
The liquid mixture, after passing through this
preheater 32, is conducted by a pipe 33 to one
extraction chamber, and with the piston in its
idle position;
70 chamber 34 of a circulating evaporator 35, in
Fig. 10 is a plan oi the same, but with the piston
in its position at the end of a movement of the
conveyor; and
Fig. 11 is a wiring diagram of some controls
that may be utilized to regulate and correlate the 75
which the mixture is concentrated. This type or
evaporator is well known and, in addition to the
chamber 3l, it also has a separator dome 36 which
is connected with the upper part of the chamber
34 by a pipe 31, the separator dome being also
2,510,221
6
connected by a pipe 33 to the lower part of the
uum pump may be included in series in the pipe
chamber 34.
In case it is desired to remove the solvent from
the extract completely and the solvent free ex
61 so as to draw the steam and air or gas through
the sectionv'9. Both sections of the drier are
tract is a liquid, the concentrated extract from
heated by steam jackets and the vapors driven
oil from the solids in the drier as well as the
steam passing through the lower section 9, will
be delivered to the condenser 64, and the con
densed mixture then passed to the separator tank
this evaporator 35 is withdrawn from the lower
part of the pipe 38, through the pipe 39 by a pump
40 which delivers the concentrated extract
56 where the water and solvent are separated.
through a pipe 4 I to a constant level tank 42. The
The drier may be of any suitable construction,
concentrated extract overflows from thistank 42 10
that shown by way of example being one which
through a pipe 43 which leads to the upper end
is suitable for this purpose, and it includes in each
of a downllow stripping column 44, in which the
section therein a conveyor by which the solids are
oil flows downward over the inside of a. number
moved slowly therethrough and agitated so as to
of tubes in the form of ñlms. These tubes are
heated on the outside to furnish the necessary 15 be thoroughly and uniformly heated, and air or
steam passed therethrough to the pipe 61. The
heat to vaporize the residual solvent. The ñn
discharge conveyor I I may be one which seals the
ished extract is withdrawn from the bottom of
outlet opening by the solids which are packed
this column F4 through a pipe 45 which conducts
tightly therein, so that steam or gas admitted
the extract through a cooler 46 and then the
cooled extract is conducted by pipe 41 to a con 20 through the pipe 66 will not pass outwardly
through the discharge device II to any appreci
centrate storage tank 48. Steam is supplied to
able extent. The conveyors in the discharge de
the stripping column 44 through pipe 49 con
vice II and the section 9 are connected together
trolled by valve 50 and pipe 49a having valve 50a,
by a sprocket chain 68, and the conveyors of the
and the solvent vapor carried off from the con
centrated extract with the aid of the directly ad 25 two drier sections are similarly connected by a
conveyor chain 69 running over sprockets on the
mitted, ascending steam in the stripping column
ends of the conveyor shafts. The conveyor of the
44 is conveyed by a pipe 5I to a separator 52 in
upper section of the drier may be operated slowly
which any entrained liquid particles are removed
through a speed changing device 10 driven by a
and returned to the pipe 43. The vapor is then
conducted through a pipe 53 to a condenser 54. 30 suitable motor .1 I.
The extraction chamber, as explained, is en
Vapors from the separator dome 36 of evaporator
closed in the housing I, the two end portions
35 may also be corducted by the pipe 55 to the
thereof being shown in Figs. 3 and 4. The lower
pipe 53, so that the vapors from both the evapo
part of this housing is liquid-tight, and at one
rator and separator 52 will pass through the same
35 end thereof (left end in figures), the bottom is
condenser 54.
curved upwardly as at 12, with its center of cur
The vapors which are condensed in the con
denser 54 are then conducted by a pipe 55 to a
vature at the axis of a shaft 13 that extends trans
A suitable elevating conveyor, such as an up
which has its center of curvature at the axis of a
the beans from the lower end of the housing to
tom of the housing at the same distance there
versely across the adjacent end of the housing at
water separator tank 56, and in that tank the
a point spaced above the bottom thereof. This
water and solvent are separated by stratification
into layers. The water is, of course, discarded 40 shaft 13 carries a. sprocket wheel 14 near each
side of the housing, and a similar sprocket Wheel
and the condensed, solvent vapors are conveyed
15 is mounted on shaft 16 disposed directly above
by a pipe 51 to the solvent work tank I6, where
the shaft 13 at the same end of and at each side
make-up solvent is supplied from the tank I3,
of the housing. The bottom of the housing I,
as previously explained.
at its other end, that is, the end opposite from
Referring now to Fig. 2 of the drawings, a hot
the curved portion 12, is given an upward in
gas, such as live steam is admitted to the lower
clination 11 (Fig. 4), which is connected to the
end of steamer housing 5 through a pipe 58, and
straight bottom part by a short arcuate strip 18
to the upper end of the same housing by a pipe 59.
standing rotating screw 5a serves to slowly moveA 50 shaft 19.
The shaft 19 is disposed above the bot
above as the shaft 13, extends across the housing
and carries a sprocket wheel 88 adjacent each
is provided with a perforate wall zone 60 which is
side of but within the housing.
surrounded by a closed shell or housing 6I having
Above the higher end of the inclined section 11
an outwardly extending passage 62. The steam 55
or bottom of the housing is a shaft 8| which also
entering the housing 5 at opposite ends thereof
extends across the interior of the housing and
will pass towards the perforate zone 60 and then
adjacent each side of the housing carries sprocket
through housing 6I into pipe 62. The pipe 62 is
wheels 82. Two endless chains 83 are disposed
connected to an ejector 63 discharging into a con
denser 64, and the vapors condensed in the latter 60 in parallel positions within the housing, one at
each side thereof, each chain passing over the
are conveyed by pipe 65 to pipe 55 leaving the
sprocket wheels 14, 15, 80 and 82 at its side of the
other condenser 54. The ejector 63 creates a par
housing. Rigidly attached to corresponding link
tial vacuum in the housing 6I, so that steam ad
portions of the chains 83 are a plurality of perfo
mitted to the housing 5 will be drawn through
the top. The housing 5, intermediate of its ends,
that housing toward the perforate zone 66 and 65 rate plates or drag flights 84, spaced apart suit
able uniform distances in a direction lengthwise
drawn off through the pipe 62 and delivered to
of the stretches of the chain, and each of these
condenser 64.
plates 84 extends in a direction normal to the
Steam or air, or both, or other suitable gas may
lengths of the chain at the points of attachment
be admitted to the discharge end of the section 9
of the drier through a pipe 66, and passed length 70 of the plate thereto, into close proximity with the
sides and bottom of the lower portion of the hous
wise of the section 9 to the entrance end of that
ing, so as to move in close proximity to the side
section, thence through pipe 8 to the discharge
and bottom walls of the lower zone in this hous
end of the other drier section, where it is removed
ing. This zone may be also referred to as the
by a pipe 61 and delivered to the entrance end of
the condenser 64. If desired, an ejector or vac- 75 extraction chamber.
2,510,221
7
8
These plates 84 have very small perforations
the positions shown in Fig. 9 to the positions
therein over the major part of their area to en
able solvent to pass therethrough from one face
to the other, but the perforations are small
enough so that the solid particles between the
plates will not pass through them. The bottom
of the housing is preferably arcuate in transverse
shown in dash lines in the same figure, which
is the position shown in full lines in Fis. 10, the
engagement of the ratchet pawl 98 with a tooth
of the ratchet wheel 90 will result in a rotation
of the wheel 90 through one-quarter of a revolu
tion, and cause a corresponding partial revolu
section so that the sides and bottom of the lower
tion of the shaft 8|.
zone of this housing will be a segment of a circle
83 through a selected distance, at the same time
This advances the chain
in transverse cross section, as shown in Figs. 5 10 lifting the weight 94. When the bell cranks 9|
and 6. The plates 84 have upstanding ears 85
are released the weight 94 will return them to
which are rigidly secured to the links of the chain
the positions shown in full lines in Fig. 9, dur
83 at each side of the housing, so that while
ing which the pawl 96 rides idly over the periphery
said plates 84 are moved with the chain, they
of the ratchet wheel into a position to engage
are held in planes at right angles to the lengths 15 behind the next tooth 98 in succession.
_
of the links to which they are attached. Thus,
The bell cranks 9| may be operated in any
when the lower stretches of the chains move
suitable manner by any suitable source of power,
along the lower part of the housing, as on tracks
but in this particular example, a hydraulic oper
86, the plates 84 attached thereto will be held
ating motor is provided. This motor includes a
rigidly in positions to extend toward the arcuate 20 cylinder 99, Fig. 9, in which a piston |00 is mount
bottom of the housing and to push along said
ed for reciprocation. Pivotally connected to a
bottom all solids that may be disposed between
wrist pin |0| of the piston |00 are two connect
the plates in said extraction zone or chamber.
ing links or rods |02, which through the pinion
These plates will thus receive between them,
| 0| , are capable of rocking movement relative
as they pass downwardly at the left hand end
ly to the piston. The other ends of links |02 are
of the housing, Fig. 3, the solids which are de
pivoted on the pin 95 which mounts pawl 96.
livered thereto through conduit 3, and the batches
These links |02 pass loosely through an aperture
or charges received between the vanes or plates
|03 in an end wall of the cylinder 99. The other
will be pushed along the bottom to the inclined
end of the cylinder is closed by a plate |04
end of the housing, thence up the inclined end 30 through which opens a pipe |05 that supplies an
and over a strainer plate 81, and then into the
operating iiuid under` pressure to force the piston'
chute 4. The bottom wall of the housing below
to the left, Fig. 9. The pipe |05 leads to a three
the strainer plate 81 is spaced therefrom slightly
way valve |06 which may be operated in any
so that any solvent carried by the solids along
suitable manner, such as by an electromagnet or
the inclined wall can drain off without being 35 solenoid |01, Fig. 1l. This valve |06 is connected
carried into the chute 4, except for the adherent
by a, pipe |08 to a source of operating ñuid un
solvent that is carried on or within the solid
der pressure, which may, for example, be com
particles. Disposed below the arcute bottom of
pressed air or any liquid under pressure.
the housing is a heating chamber 88 in which
The interior of the valve housing is subdivided
steam coils 89 are disposed in contact with the 40 by partitions into three compartments |09, ||0
bottom wall, so that heat can be conveyed to the
and | I | (Fig. 1l) , arranged end to end and com
solids within the compartments formed between
municating with one another by openings in said
the plates or vanes 84 and the sides and bottom
partitions. These openings have valve seats
of the extraction zone or chamber. Thus, the
which engage with corresponding closure por
solids and solvent in the extraction chamber may
tions | I2 and I |3 of a valve element that is con
be kept warm, which accelerates the solvent ex
nected to the armature o_r core ||4 for move
traction operation, and generally increases the
ment by the coil |01. A spring ||5 urges the
solubility of the component extracted in the sol
valve element in a direction to close communica
vent.
tion between the pipe |08 and chamber |09, it
The shaft 8| extends exteriorly of the cas 50 being understood that the pipe |05 opens into
ing at one side and carries a ratchet wheel 90,
the intermediate chamber |09. An exhaust pipe
Figs. 2, 5, 9 and 10, which is ñxed thereon. This
||6 is connected to the end chamber ||0.
'
wheel 90 is given increments of rotation in a
The valve element normally closes communi
manner which will be explained presently, and
cation between the compartments or chambers
this causes increments of movement of the end
|09 and III but connects the chambers |09 and
less conveyor formed by the chains 83 and the
||0. This places the pipes |05 and ||6 ín com
vanes 84, so as to gradually move the conveyor
munication with one another and vents cylinder
in a direction to push the solids under treatment
99. Valves of this type are well known in the
slowly through the extraction zone of said hous
art and are available in the open market, so that
ing. To impart such increments of rotation to . further explanation thereof is unnecessary.
the ratchet wheel 90, the shaft 8| mounts rotat
When the coil |01 is energized, it raises closure
ably thereon and at each side of the wheel 90,
portions ||2 and ||3 and connects pipe |08 to
a pair of bell crank levers 9|. Each of the arms
pipe |05 and disconnects pipe |05 from exhaust
of each of these bell crank levers is pivoted by a
pipe IIS. This causes the admission of fluid
pin 92 to a rod 93 depending therefrom and pass 65 under pressure to the cylinder 99, and the piston
ing through a supporting weight 94. The other
|00 is forced to the left in Fig. 9, to cause an
arms of the bell crank levers 9| are connected
together by a pin 95 which, intermediate of its
advance of the sprocket chains and drag nights. -
When the coil |01 is deenergized, fluid under
pressure delivered by pipe |08 is discontinued
ends, mounts a pawl 96 that has a nose 91 formed
to engage with notches or teeth 98 formed in 70 and the cylinder is vented through pipe IIS.
the periphery of the ratchet wheel 90.
These notches or teeth 98 are spaced equally
about the periphery of the Wheel, and in this
whereupon the weight 94 returns piston |00 to
its right hand position in Fig. 9 and returns pawl
96 to a position to engage in the next successive
particular example, four notches 98 are shown.
notch 98 in the ratchet wheel 90. Any suitable
When the bell crank levers 8| are rocked from 75 means for controlling the solenoid |01 may be
2,310,921
employed, but the arrangement shown in Fig.
11 will serve that purpose. In this wiring di
agram of Fig. 11, the number of energizations
of the coil |01 in a selected period will, of course,
depend upon the rate at whichthe solids are
to be advanced through the extraction chamber,
and this rate will vary with the time required
for complete extraction. For example, in the
case of extraction of caffeine _from coffee beans,
an extraction period of forty-eight hours may be
required, while for some other materials, a much
shorter period,'such as only one hour/might be
sufficient for the extraction treatment. Appa
ratus for the extraction of caffein from coffee
beans requires a rather long extraction cham
ber.v For example, it may be forty-eight feet
10
to the scoops ||1 on a one 'to one ratio, >and
hence will rotate in timed relation thereto.
A continuously running, constant speed motor|32, (Fig. 11) is connected through a speed re- ,
duction gear train |33 to drive a contact disk
|34 at a rate of approximately one revolution
per hour. 'I'he disk |34 is rotatably mounted on
a shaft |35, y¿and a. second contact disk |36 is
fixed on shaft |35 and is driven at a different
10 rate, such/as one revolution per. minute. A
speed> reduction train R corresponding to the
dial train of a watch or clock, that is, a train
which connects the hour and minute hands of
a watch or clock, is connected between shaft |35
and disk |34, so that while the disk |34 makes
one rotation, the disk | 36 will make many more
rotations, such as one per minute. The disk |34
long, in which case the rate of movement of
carries a cam pin |31 and the disk |36 carries
the drag flights 34 will be about one foot per
a cam pin |38. The_pin |31, in passing a par
hour. Accordingly, the >control should operate
in such a manner that the flights move only 20 ticular position in its rotation, will engage and
operate momentarily a switch |39, and the pin
once an hour over a distance of one foot, where
|38 in passing a corresponding .position will
the -flights are spaced one foot apart.
engage and forcibly close momentarily another
Extending across, from side to side of the
switch |40. The two switches |39 and |40 are
housing, are a plurality of channel `bars ||5a,
(Figs. 5-8) spaced apart along and just above 26 connected in series by a wire |4 | .
The other side of the switch |40 is connected
the lower stretches of the chains 83. Approxi
by a wire |42 to a line wire L“, and the other
mately midway across the housing, these channel
side of switch |39 is connected by a wire |43
bars support bearings ||6a which in turn rotat
> ably support an agitator element having a plu
f rality of agitator arms
||1.
to one end of a closing coil |44 of a latch-in
Latch-in relays are available in the
open market under that name, and when oper
ated, the armature is mechanically latched in ’
operated or closed position, and so held and re
These arms are 30 relay B.
preferably in the form. o_i.' shallow scoops and
are arranged to extend alternately from diamet
rically opposite sides from their vaxis of rotation.
These arms or scoops may be perforate, with the
leased by a reset coil. For identification, such
size of the perforations small enough to hold 35 relays are marketed by Struthers Dunn, Inc.,
#1315 Cherry St., Philadelphia, Pa., and shown
back most of the solids, but yet allow the solvent
on page 21E of its catalogue E of October, 1940.
to pass therethrough. In the particular example
The other end of the coil |44 is connected by
illustrated, the arms ||1 have tubular bosses
a wire |45 to one‘ end of a reset coil |46-of
||8, see Fig. 8, which are connected at adjacent
ends to one another by short shaft lengths or 40 another latch-in relay C. The other end of coil
|46 is connected by wire |41 to a line wire L’.
rods ||9 which pass through the bearings ||6a.
The relay B is provided with a reset coil |48
Suitable members, such as pins |20, pass through
which is connected at one end by a wire |49
the tubular bosses of the scoops and rods ||9,
to the wire |42,>and at its other end by a wire
so as to connect them together for rotation as
a unit. There are, in the illustrated example, 45 |50 with a contact |5| of the relay C. The
other contact |52 of that relay C is connected
two such scoops for the space between each pair
by a wire |53 to one side of a switch |3|, the
of drag flights or vanes 84, and the scoops may
other side of that switch being connected by
be constructed in pairs with the scoops or arms
of each pair extending in opposite directions
a wire |54 to one end of a reset coil |55 of a
from the axis of rotation as shown in Fig. 3. 50. latch-in relay E. 'I'he other end of reset coil
|55 is connected by wire |56 to line wire L'.
These stirrer arms or scoops ||1 rotate slowly
The relay B has two contacts |51 and |58.
so as to laterally displace or stir the Solid par
Contact |51 is connected to wire |42 and con
ticles in each batch or quantity between adjacent
tact |58 is connected by a wire |59 to one end
vanes or drag flights 84, and in the case of coffee
beans, this speed or rotation may be, for ex 55 of the closing coil |60 of the relay C. The other
end of coil |60 is connected by wire |6| to one
ample, 2 R. P. M. or one revolution in thirty
seconds. Obviously, this rate may be varied . side of a switch |30, the other side of switch |30
being connected by wire |62 to one end of a
extensively, depending upon what rate of stir
closing coil |63 of the relay E. The other end
ring is desired.
Fastened on this rotating element having the 60 of coil |63 is connected to the line wire L’. The
relay E has a pair of relay contacts |64 and |65.
scoops is a sprocket wheel |2|, Fig. 7, which is
The contact |65 is connected by a wire |66 to
driven by a _sprocket chain |22 leading to a
one end of the solenoid or electromagnet |01 of
sprocket wheel on a countershaft |23, Fig. 2,
the valve |06. The other end of the coil |01
which is driven by a chain |24 from any suitable
source of motive power. This countershaft |23 y 65 is connected by wire |61 to line wire L'. The
contact |64 is connected to line wire L2.
is mounted on the side of the housing I in any
The disks |34 and |36 with their ratio of rates
suitable manner and is rotatably supported in
of revolution and operated at a constant speed by
bearings |25. Fixed on the shaft |23 are disks
a continuously running motor |32 constitute what
|26 and |21, which have cams or contact points
|28 and |29, (Fig. l1) respectively, there being 70 may be called, for convenience, a timer for clos
ing switches |39 and |40. These switches |39
two cams |28 on the disk |26 and two cams |29
and |40 are both closed at the same time momen
on the disk |21. The cams |29 function to close
tarily once for every revolution of the disk |34,
momentarily a switch |30, and similarly, the
which period may be the desired frequency of in
cams |28 will close momentarily a, switch |3|,
crements of movement of the drag flights or '
75
The disks |26v and |21 are drivingly connected
‘2,510,221
11
12
vanes in the extraction chamber. The disk |36,
by reason of its rotation at the more rapid rate
will close the switch |40 once for each rotation
thereof, but unless the switch |39 is also closed
at the same time by the cam |31, no change in the
circuit arrangements will occur. Since the disk
|34 is rotating relatively slowly, and only a
momentary contact or contact of short duration
is desired for the circuit, including the switch
|39, the circuit will not be closed except for the
shorter period while cam |38 closes switch |40
between contacts |64 and |65 thereof. This de
energizes the coil |01 of the electromagnetically
operated valve |06, allowing this valve to discon
nect pipes |08 and |05, and to reconnect pipe
|05 to the exhaust pipe ||6. The piston | 00 is
then returned to its initial position by weight 94
because, the operating ñuid can escape from hy
draulic motor to exhaust pipe ||6.
When current passed through the last described
circuit. it also energized the reset coil |48 in the
relay B, and thus opened this relay from its me
in paw'îng the same at a more rapid rate.
chanical latch. This opened the circuit through
When switches |39 and | 40 are both closed at
the closing coil |60 of the relay C and thus
the same time, which will be once for every hour.
opened the circuit through the switch |3| before
for example, a circuit is momentarily established 15 that switch could be closed a second time by one
as follows: from line wire l'.,2 through wire |42,
of the cams |28. This arrangement prevents an
switch |40, wire |4|, switch |39, wire |43, \ operation of the electromagnet _or solenoid of
energizing coil |44 of latch-in relay B, wire |45,
the valve |06 except when disks |34 and |36
reset coil |46 of latch-in relay C, and wire
close switches |39- and |40 simultaneously, which
|41 to line wire L’. This> energizes the clos 20 is the time when the drag flights or vanes of the
ing coil of latch-in relay B. The energlzation
conveyor are to be operated or moved. If the
of the closing coil |44 of, relay B causes com
disks |34 and |36 closed switches |39 and | 40
pletion of a circuit between contacts |51 and
and caused an operation of the relay B, and the
|58, but no current can flow through this circuit
disk |25 closed the switch |3| before the disk |21
so established until the disk |21 carries one of its 25 closed the switch | 30, then the relay B would open
cams | 29 past the switch |30 and closes it, Since
again before the flights could move, and an entire
the cams |29 are 180° apart on the disk |21, and
period controlled by disks | 34 and |36 would pass
shaft |23 rotates with and at the same rate as the
before another movement of the flights or endless
arms ||1, the switch |30 will be closed every half
conveyor was possible. To prevent this, the relay C
revolution of the'scoops. These cams |29 are so 30 is provided so that when the disks |34 and |36
arranged on the disk |21 that the switch |30 will
close the switches |39 and |40, the reset coil |46 of
be closed only when the scoops are entirely at a
the relay C is energized, which opens the relay C
level above and clear the drag flights or vanes in
and thus opens the circuit between the contacts
the lower stretch of the conveyor which runs .
|5| and |52.
.
through the lower part of the extraction hous 35
If the switch |3| is closed before switch |30, no
ing.
current flows through the contacts |5| and |52 of
Since the relay B is latched in closed circuit
relay C, and the relay B remains closed until the
position when energized, the circuit made between
switch |30 closes and the solenoid-operated valve
the contacts |51 and |58 thereof, upon passing
| 06 has had an opportunity to operate. As soon
current through coil IM, will remain closed, and 40 as the switch | 30 closes, current passes through
as soon thereafter as either cam | 29 on disk | 21
the closing coil |60 of relay C, thereby closing a
closes switch |30, a circuit will be established as
circuit through the contacts |5| and |52, making
follows: from line wire L? through Wire |42,
this circuit ready to function when the switch |3|
contacts | 51 and |58. of relay B, wire |59. clos
closes. The relay C remains closed for the full
ing coil |66 of relay C, wire |6|, switch |30, wire 45 period between movements of the drag nights
|62, and closing coil |63 of a latch-in relay E to
until the disk; |34 and |36 again close switches
line wire L'. When this circuit is closed, the
|39 and |40. At every half revolution of the
relays C and E will both be closed or operated
scoop unit. the switch |3| will be closed and cur
and mechanical latches keep these circuits
» rent could flow through the circuit controlled by
closed. When the relay E closes, it completes a 50 the contacts |5| and |52 of relay C and through
circuit as follows: from line wire L2, contact |64,
the reset coils of the relays B and E if relay C was
vcontact |65, wire |66, valve solenoid coil |01 and
closed. Since these relays B and E are opened
wire |61 to line wire L'. This operates the valve
the first time that the switch |3| closes after
| 06 and causes fluid under pressure to be admitted
movement of the flights or vanes, any such ñow
to the hydraulic motor shown in Fig. 9, which 55 of current every half revolution is immaterial.
causes the piston |00 to move to the left and ad
vance the drag flights or vanes a given incre
ment of movement determined by the extent of
movement of the shaft 8 I. This movement should
It will be understood that the method of syn
chronizing the movements of the agitator or
scoop shaft and of the endless conveyor which
moves the flights or vanes by increments, is only
be fairly rapid so as to require only a short inter 60 an illustration of one example and obviously
val of time, while the rotating stirrers or scoops
other means ,for accomplishing the same result
are above the vanes or drag flights.
may be employed. It will also be understood
The disk |26 is so mounted on the shaft | 23
that suitable safety measures may be employed
relatively to the disk |21, that the cams |28
to prevent damage in the event that the pres
thereon will close the switch |3| after the piston 65 sure is insufficient to operate the endless con
|00 has moved its full stroke, but before the
veyor promptly within the time desired, or to
switch |30 is closed a second time by the other
stop the operation if the controls should fail,
cam |29. The switch~|3| when closed, completes
or should the endless conveyor attempt to oper
another circuit, as follows: from line wire U
ate when the scoops or agitator arms are in the
through wire |42, wire |49, reset coil |48 of relay 70 path of the vanes or flights. Since such safetl1
B, wire |50, contacts |5| and |52, wire |53, switch
devices 'are separate and divisible inventions,
|3|, wire |54, reset coil |55 of relay E and wire
they have not been illustrated or described.
|56 to line wire L'. The closing of this circuit
It is believed that the operation of this ap
energizes the reset coil in relay E, which releases
paratus will be clear from the foregoing descrip
the relay and causes an opening of the circuit 75 tion, but it will be briefly, referred to by way of
,2,510,921
‘
.
13
summation. Assuming that th‘e apparatus is
used for the extraction of cai'fein from conee
as one example of the application of this inven
tion to industry, theraw conce beans, unground,
and either dry or previously soaked in water, are
_supplied - to the hopper 2 and fed therefrom
through chute l to one end of, the extractor
housing I. ’l'he beans entering the housing I en
gage upon one of the vanes or nights Il which
is in the vertical stretch at that end of the hous
ing, and then as the conveyor moves along the
coffee beansl supported thereon, will descend into
the lower part of the housing through which the
solvent for the extraction is flowing. The beans ’
will be pushed along in individual batches or
charges by increments of movement, so that the
desired elapsed time will occur before the coilee
beans complete their travel through the lower
part of the housing and are discharged into the
chute 4. At _the same time, solvent recovered
from the previous treatment of coiïee beans will
-» 14
>
Fig. l, and thence to water'separatcr tank Il.
after which. the ccndemed pure solvent is re
turnedtothetank liforuseinthetreatment
of further beans. The beans
into the
chute 6 from the steamer have very little solvent
left therein, but any which is left is largely with
in the beansthathas not been dinused out
wardly during the treatment in the steamer l.
The beans thus pass tbroughthe chute or con
-duit 6 to the upper section of the drierv 1, where
they pass through a heated chamber.
The conveyors in the drier 1 are rotated b!
the motor ‘Il and the beans are gradually moved
throughthe upper section of the drier to the left
hand end thereof, then to the lower section 9.
. thence to the right hand end of that section.
then by chute Il to the discharge sealing device
II. During this travelof thebeansinthedrier,
they are dried, and all vapor, moisture and sol
vent removed from the beans while in this drier
will be conducted to the pipe 51. If desired, a
-' small amount of steam may be admitted to the
be supplemented with make-up solvent from the
lower section of the drier so as to remove the last
tank I3 and this mixture supplied by pump I8
part of the solvent from the beans, and the
and pipe I5 to a preheater 2l, Fig. 2. The heated
vapors therefrom pass upwardly through the
mixture will be delivered by pipe 2| to the lower 25 chute '8 and then out through the vapo'r removal
part of the housing I.
pipe t1. It will be understood that various forms
The solvent liquid then nows through the low
of steamers 5 and driers 1 may be employed with
er part of the housing to the screen S at the out
in the principle and scope of this invention, be
let opening with which the pipe 22, Fig. 3, is con
cause the details thereof are not, per se, a part
nected, the position of the outlet pipe 22 deter
of this invention, and any well known examples
mining the level of the solvent in the housing I.
of apparatus found in the market may be em'
This level is indicated, >for example, by the broken
ployed in this particular system.
»
It
will
be
noted
that
the
`
line X-Y in Fig. 3.
While the stripping column ll may be elimin
solvent and beans move in opposite directions
ated. it is useful in many instances where the
through the extraction chamber, and that the 35 solvent-free extract is a liquid in an enort to
stirring by the arms or scoops II‘I causes local ' recover as large a percentage as posible of the
relative displacement of the beans in directions
solvent, and to have as little solvent as possible
crosswise of the general direction of travel of
in the concentrated extract delivered to the stor
the solvent through the extraction chamber. The
age tank I8. These stripping columns u, sepa
solvent with the extractive principle carried 40 rators 52, constant level tanks I2 and evaporators
thereby is delivered into the miscella storage
35 are well known apparatus which have been
tank, as previously explained, and this extract
used in the industry for various purposes, and
is then concentrated and stripped of the surplus
`for that reason they have been illustrated only
solvent. The surplus solvent is then condensed
diagrammatically.
c
45
and returned to the tank Ii for the treatment of
The counternow treatment of the solvent and
further beans, that is, for recirculation through
beans is continuous and slow, and it will be noted
the housing I. The beans, after the extraction A that the scoops or arms II'I make a plurality of
treatment in the housing I, and when discharged
rotations or stirring operations between succes
through the chute 4, pass to the lower end of
sive movements of the nights or vanes Il, so that
the steamer 5, where they are carried by a screw
or endless conveyor to the top thereof, and there
discharged into chute 6. As the beans pass up
wardly through the steamer 5, they are com
pacted by gravity which prevents channeling and
at the same time, they are subjected nrst to steam
admitted through the pipe 58, which steam rises
with the beans 'to the perforate zone Sli. Such
steam removes most of the excess solvent which
maybe adhering to the beans and also tends to
remove solvent from the interior of the beans by
dinusion of the solvent to the exterior of the
beans.
'
Similarly, steam entering through the pipe 59
at the top of the steamer passes downwardly
through the ascending beans, and this irezh
steam which engages the beans about to be dis
while the progress of the beans through the ex
traction chamber is relatively slow, there is sunl
cient agitation or local, lateral, relative displace-V
ment of the beans by the arms II‘l to break up
any tendency of the solvent tc channel in its
movement through the chamber. In that way,
the now of the solvent is uniform throughout the
entire mass oi! beans as they travel in individual
batches or charges through the extraction cham
ber or zone. Thus, all of the beans get substan
tially the same treatment, and the extraction is
uniform and as complete as possible. Because of
the slow Arotation of the arms Ill, the beans will
not be thrown from one compartment to another.
VThe solvent will pass from compartment to com
partment through the apertures or perforations
-in the drag nights or vanes 8l, and the coordina
tion of the movements 4of arms II'I with the
ahnost free of solvent and carry it downwardly
movements of the drag nights or vanes 8i will
to the perforate zone 60. The steam coming
prevent any collision between> the vanes Il and
from opposite ends-of the steamer 5 will pass 70
stirring arms. à
through the perforate zone 60 into the housing
In ease the solvent is lighter than water, the
5I, thence through pipe 62 to an ejector which
condensate from the condensers will now into the
creates a. partial vacuum inthe housing 6I. The
charged into the chute E, will strip the beans
water separating tank in the center and the sol
steam, with the solvent vaporsA carried on in this
vent
will now from the top of this-tank into the
15
manner, is then conveyed to the condenser 6I,
2,510,221
`
’
‘
15
16
,
solvent work tank. When the solvent is heavier
than water, it will settle to the bottom of the sep
arating tank and will-pass therefrom into the
solventl work tank. This apparatus may be em
ployed for the solvent extraction treatment oi
materials that are either heavier or lighter than
the solvent. When used with materials that are
lighter than the solvent, the agitator arms IIT
will preferably revolve in directions which will
have a tendency to force the material into the liq
uid, whereas ii' .the materials are heavier than the
solvent and collect at the bottom of the extrac
tor, the stirring arms will be designed to lift the
material from the bottom and deposit it in the
upper part of the solvent stream. In the treat
ment of coffee, it will be understood, of course,
that if desired, the beans may be iirst soaked in
water by apparatus, not shown, before discharge
said conveyor means travels, movable in a direc
tion crosswise of said travel of said charges, andV
operable to stir locally the particles of said
charges in succession as the charges progress
along said path.
~
2. Solvent extraction apparatus comprising a
housing having a water-tight lower portion and
with its bottom wall rising at an incline toward
and adjacent one end, an endless, Aflexible con
veyor disposed within said housing with a lower
stretch disposed above and parallel to said bot
tom wall including said inclined portion of said
bottom wall,~ said conveyor having perforate
plates spaced apart along the same and extending
normal to the direction of travel of the conveyor
in said lower stretch and into close proximity to
the sides and bottom walls of said housing in
cluding said inclined portion, whereby said plates
into the hopper 2, in order to accelerate the entry
on the lower stretch‘of said conveyor will form
of the solvent into the unground beans.
20 with the lower part of the housing a plurality
While speeiñc reference has been made as a
of compartments arranged in succession along
matter of convenience to the treatment o1' coilîee
the lower part of said housing and up said in
beans for the extraction of cail’eine therefrom, it
clined bottom portion, means for discharging
will be understood that this is by way of example
particles to be treated for extraction into that
only, and that similar apparatus may be employed 25 end of said housing which is opposite the end
for the treatment of other solids as previously
with the inclined bottom whereby when said
mentioned herein. 'I'he solvent used may vary
for different materials or solids to be treated. As
a matter of record, various solvents have been
conveyor moves in a direction to carry its lower
such case it is undesirable to use `a stripper for
and then up said inclined portion, said housing
stretch toward the inclined end and along the
bottom thereof, said particles will ñll said com
' used for the extraction of cail'eine from coñ'ee, 30 partments in succession and said filled compart
one such solvent being 'trichlorethylene, but in
ments will move along the bottom of said housing
treating the concentrated extract. The stripper
is mainly used where the extractive principle is
having a discharge opening at the upper end of
said inclined bottom, whereby the particles may
an oil or similar material. A different type of 35 be discharged by gravity from said compartments
drier may advantageously be employed for the '
as they reach the upper end of said inclined bot
coiîee beans.
tom wall, means for moving said conveyor by in
If the apparatus is used for extracting tannin
crements, with intervals of rest between said
extract from woods, such as chestnut, hemlock,
movements, means including stirrer members
oak, spruce, etc., then water is commonly used as 40 disposed above the path of travel of said plates
a solvent, and no stripper would be used for the
with said lower stretch of the conveyor, movable
extract. - The drier would not be needed for the
wood chips. The steamer is usually employed
in a direction crosswise of the direction of move
ment of said conveyor downwardly into and out
when the solids or particles to be treated are not
of some of said compartments of said lower
greatly crushed or ground because the larger par 45 stretch and immovable in the direction of move
ticles usually need extra steaming after extrac
ment of said conveyor for stirring the particles
tion in order to get out all of the solvent. Such
in said compartments at different positions of
apparatus is also very useful for the extraction of
said compartments in their travel along the bot
oil from soy beans, in which case a suitable sol
_tom of said housing, means for correlating the
50
vent could be hexane. When using soy beans, it
movements of (said stirring means and said con
is not necessary that the beans be passed through
veyor to prevent collision of said stirring means
the extraction treatment unbroken and, in fact,
and said plates, and means for passing a solvent
the beans may be advantageously ground or
liquid through the lower part of said housing at
flaked ñrst.
a level below the upper end of said inclined bot
It will be understood that various changes in 55 tom.
the details, materials and arrangements of parts,
3. Solvent extraction apparatus comprising a
which have been herein described and illustrated
housing having a water-tight lower portion and
in order to 4explain the nature of the invention,
with its bottom wall rising at an incline toward
may be made by those skilled in the art within
and adjacent one end, an endless, flexible con
the principle and scope o1' the invention as ex 60 veyor disposed within said housing with a lower
pressed in the appended claims.
stretch -disposed above and parallel to said bot
I claim as my invention:
tom wall including said inclined portion of said
1. In apparatus for solvent extraction from
solid particles, in which the particles and liq
bottom wall, said conveyor having perforate
plates spaced apart along the same and extend
uid solvent are passed in opposite directions 65 ing normal to the direction of travel of the con
through an extraction chamber. that improve
veyor in said lower stretch and into close prox
ment which comprises conveyor means bodily
imity to the sides and bottom walls of said hous
movable through an extraction zone of said
ing including said inclined portion, whereby said
chamber in one direction and having subdivisions
plates on the lower stretch of said conveyor will
for conveying said particles in separate indi 70 form with the lower part of the housing a plu
vidual charges, in succession, bodily through
rality of compartments arranged in succession
said chamber, means for passing a solvent
along the lower part of said housing and up said
through said chamber, and a plurality of stirring
inclined bottom portion, means for discharging
members arranged and spaced apart along the
particles to be treated for extraction into that
path of travel of said subdivisions and past which 75 end of said housing which is opposite the end
'
2,510,221
with the- inclined bottom whereby when said-con
veyor moves in a direction to carry its lower
stretch toward the inclined end and along the
bottom thereof, said particles will fill said com
partments in succession and said filled compart
ments will move along the bottom of said housing
and then up said inclined portion, said housing
6. Solvent >extraction apparatus comprising a
housing, means lfor circulating a solvent through
the lower part of said housing, vconveyor means
within said housing and having perforate plates.
moving along the sides and bottom of said lower
part of said housing and forming therewith a
plurality of compartments, said plates being mov
able along said lower part progressively so as> to
cause progressive movement of said compart
said inclined bottom, whereby the particles may
ments through said lower part, means for moving
be discharged by gravity from said compart 10 said plates by increments with periods of rest
ments as they reach the upper end of said in
therebetween, a shaft disposed above and along
clined bottom wall, means for moving said con
the path of travel of said plates, mounted for
veyor by increments, with intervals of rest be
-rotation, and having arms thereof movable down
tween said movements, means including stirrer
wardly into and upwardly from the compart
members disposed above the path vof travel of 15 ments in succession as the latter move along said
said plates with said lower stretch of the con
lower part, means for rotating said shaft, and
veyor, movable in a direction crosswise of the
ycontrol means cooperating with said shaft rotat
direction of movement of said conveyor down
ing means and said conveyor moving means for
wardly into and out of some of said compartments
preventing movement of said compartments when
of said lower stretch and immovable in the direc 20 movement of said plates is obstructed by arms
tion of movement of said conveyor for stirring
depending into said compartments.
the particles in said compartments entirely lo
'1. The continuous method of solvent extraction
cally for each compartment and in direction
of a dissolvable component from solid particles,
having a discharge opening at the upper end of
crosswise of the direction of travel of said com
partments, at different positions of said compart
which comprises passing said particles in sepa-î
25 rate, individual charges progressively and in suc
ments in their travel along the bottom of said
cession along a predetermined path, by increment
housing, and means for passing a solvent liquid
of movement separated by periods oi non-move
through the lower part of said housing at a level
ment, passing an extraction `solvent through said
below the upper end of said inclined bottom.
charges insuccession in a selected sequence, and
4. Solvent extraction apparatus comprising a 30 displacing said particles entirely within each
housing having a liquid-tight lower portion, an
charge relatively to each other, and separately
endless conveyor within said housing and having
from the other charges, in directions generally
a lower stretch extending within and along said
crosswise of said path of> travel of said charges
lower portion, above, parallel to, and spaced from
during said periods of non-movement along said
the bottom of said housing, said conveyor having 35 path, whereby the degree of solvent extraction
action on said particles will have uniformity
throughout the charges and all particles in each
charge will have substantially equivalent extrac
the conveyor and of a size to move along and in
close proximity to the bottom and side walls of
tion treatment.
8. Solvent extraction apparatus comprising a
the housing in said lower portion, means for cir 40
housing having a water-tight lower portion andA
culating a solvent through said lower portion of
plates extending therefrom in a direction approx
imately normal to the direction of movement of
said housing, a shaft extending above the upper
edges of the plates carried by the lower stretch
of the conveyor and having arms thereon rotat
with its bottom wall rising at an incline toward
and adjacent one end, an endless, flexible con
veyor disposed within said housing with a lower
ing, upon rotation of said shaft, to move into and 45 stretch disposed aboveA and parallel to said bot
tom wall including said inclined portion of said
out of the compartments between adjacent plates
bottom wall, said conveyor having perforate
and agitate and stir the particles in the com
plates spaced apart along the same and extend->
partments, and means for rotating said shaft 1n
ing normal to the direction, of travel of the con
coordinated relation to the travel of said con
veyor to prevent collisions of said arms and plates. 50 veyor in said lower stretch and into close prox
imity to the sides and bottom walls of said housing
5. Solvent extraction apparatus comprising a
including said inclined portion, whereby said
housing having a liquid-tight lower portion, an
plates on the lower stretch of said conveyor will
endless conveyor within said housing and having
form with the lower part of the housing a plurality
a lower stretch extending' within and along said .
lower portion, above, parallel to, and spaced from 55 of compartments arranged in succession along the
lower part of said housing and up said inclined
the bottom of said housing, said conveyor having
plates extending therefrom in a direction approxi
mately normal to the direction of movement of
bottom portion, means for charging particles to be
treated for extraction into that’end of said hous
ing which is opposite the end with the inclined
the conveyor and of a size to move along and in
close proximity to the bottom and side walls of 60 bottom whereby when said conveyor moves in a '
direction to carry its lower stretch toward the
the housing in said lower portion, means for cir
inclined end and along the bottom thereof, said
culating a solvent through said lower portion of
particles will fill said compartments in succession
said housing, a shaft extending above the upper
edges of the plates carried by the lower stretch 65 and said filled compartments will move along the
lbottom of said housing and then up said inclined
of the conveyor and having arms thereon rotat
portion, said housing having a discharge opening
ing, upon rotation of said shaft, to move into and
at the upper end of said inclined bottom, whereby
, out of the compartments between adjacent plates
the particles may be discharged by gravity from and agitate and stir the particles in the com
partments, and means for rotating said shaft in 70 said compartments as they reach the upper end
of said inclined bottom wall, means for moving
coordinated relation to the travel of said con
said conveyor by increments, with intervals of
veyor to prevent collisions of said arms and plates,
rest between said movements, means disposed
said arms being in the nature of scoops which dip
above the path of travel of said plates with said
into the compartments between plates during
their lower swing with said shaft.
75 lower stretch of the conveyor and immovable in
9,510,921
the direction oi' movement of said conveyor for
stirring the particles in said compartments at
different positions of said compartments in their
travel along the bottom of said housing, "and
means for passing a solvent liquid through the
lower part of said housing at a. level below the
upper end of said inclined bottom.
GUY N. HARCOURT.
REFERENCES CITED
The following references are of record in the
me of this patent:
l)
UNn'm s're'rns PA'rmrrs
Number
Name
Date
2,107,537
2,111,360
2,183,837
2,204,777
2,227,605
2,231,154
3,254,390
2,276,298
2,280,811
2,381,965
Jones ...... -.._.---.... Feb. 8, 1988
‘Cutting ____ ___..- Mar. 15, 1938
Hamilton .......... _- Dec. 9,
Smith ......... -_ June 18,
Swailin ......... _;...._ Jan. 7,
Chesny ........... _- Feb. 11,
Levine ........ __ Dec. 2,
1939
1940
1941 '
1941
1941
Frazier ---..-._..._-_ Mar. 17, 1942
Edhoier ........ _.- Apr. 28, 1942
i Berry -..-......_..- Aux. 14. 1945