Year: 1887

page_text: This Specification was, upon the 25th day of August 1890, Amended unde
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act 1883.
and in the Separation of those Salts.
A communication from abroad by Doctor SIGISMUND PICK, of Szezakowa, in
Galicia.
T. GEORGE ISAAC JAMES WELLS, of 41, Francis Terrace, Victoria Park, in the
County of Middlesex, Manufacturing Chemist, do hereby declare the nature of this
invention to be as follows:-
The apparatus to be described hereafter is based upon the same principle as the so
called Rillieux apparatus, which as a rule is in use almost in every beet sugarworks.
While such apparatus is sometimes applied in other works for the evaporation of clear
liquors up to a certain strength, it is not applied for the evaporation of liquors, from
which salts are precipitated in the course of the evaporation in consequence of the
difficulty of separating these salts from the liquor during the evaporation and of
keeping the process as a continuous one. The new apparatus does away with this
difficulty and offers some other advantages besides.
The principle of the Rillieux apparatus may be taken as well known shortly it
may be described as the utilisation of the latent heat of the steam in connection with
the lowering of the boiling point, by employing a pressure below the ordinary atmo
spheric one. In such way one is enabled to keep up an energetic evaporation of a
liquor having a high boiling point by means of the ordinary exhaust steam from
engines and to use over the steam so produced for the evaporation of another portion
of the same liquor and so on.
In carrying out the invention, I form three (or more) boilers, (preferably vertical,
but other forms may do) connected together as in the usual triple-effect apparatus,
IP SZI

page_text: Each of these has two preferably horizontal diaphragm tube plates occupying the
entire cross sectional area or nearly so, so as to enclose a central chamber for heating
steam, and from one tube plate to the other, I insert a number of tubes connecting the
part above the chamber with the part beneath. Into the tube chamber in No. I the
steam from a boiler or other source is passed, by means of a pipe and valve and into
each of the others the steam from the previous apparatus Nos. and 2 respectively is
passed. The boilers below the steam chamber are preferably funnel shaped with a
slide valve at bottom and below this in each case the vacuum filter is fixed hereafter
described. Each of the steam heating chambers has a pipe leading to a condenser and
air pump (to exhaust the water and non-condensible gases), reducing valves can be
placed on these pipes or some of them if desired to regulate the pressure, or other
means, such as different heights in a column of water can be used for the same
purpose.
The action of these triple effect boilers is as follows:-
The three boilers being filled to usual water line, the steam either direct steam from
boilers or exhaust steam from engines enters No. I steam heating chamber through the
valve, and passes round the tubes heating the same and the liquor contained therein.
The steam as it condeuses is led off to the condenser by the pipe already described.
The steam evaporated from No. 1 enters the steam heating chamber of No. 2 and that
of No. 2 enters the chamber of No. 3. No. 3 boiler is connected on the top through
a pipe with a separator (where the particles of the liquor carried away by the steam
are separated) and also with a condenser and vacuum pump. A strong vacuum is so
formed in No boiler by the condensation of the steam and the pump. Consequently
the liquor therein boils at a very low temperature. The heating of No. 3 is effected
by the steam coming from No. 2 passing round the tubes in the same manner as in
No. 1. Through this condensation of the steam a vacuum is formed in No. 2 änd the
boiling point fowered. In No. 2 the liquor is heated through the evaporation of the
liquor in No. 1. The condensation of this steam in No. 2 forms a vacuum therein,
and consequently lowers the boiling point there. Therefore the highest temperature
of the liquor exists in No. 1 boiler, and the lowest in No. 8, while the strongest
vacuum is in No. 3 and the weakest in No. I. A most energetic evaporation is
obtained in this way. The liquor passes in the same manner as the steam from No. 1
No. 2 to No. 8. It cuters No. 1 through a valve and pipe, either it
runs in from a
higher reservoir through its own weight, or it is drawn in from a
lower one through the vacuum. The most concentrated liquor leaves No. through
a pipe and valve, it goes in a closed reservoir, which is standing below the level of
No. and is connected through an air pipe with the condenser. As the same vaenum
is formed in this reservoir as in No. 8, the liquor runs into it by its own weight, of
course the speed of the liquor has to be regulated according to the evaporation.
to No. 2, from
The separation of the salts, which are precipitated through and during the evapora-
tion, is effected in the following manner. No. 1 No. 2 & No. 3 have slide valves at
their conical bottom parts as already described. With these slide valves. vacuuan
filiers below are connected. These filiers consist of a top part, a little conical and a
cylindrical bottom part. The filtering material (perforated plates, wire, gauze, cloth
layers of minerals) is fixed between the two parts. The top part has an air tap a
water pipe ending in a rose and a man hole on the hottom. The bottom part has
gauge glasses and is connected through the pipe with the top part of No. 3, as this
apparatus has the strongest vacuum. These vacuum filiers are worked in the following
manner. The slide valve is opened and the filter filled with liquor. The precipi
fated salts drop through the opening of the slide valve in the filter and rest in the
filtering material. When the top part of the filter is full with salt or nearly full, the
slide valve is closed and the valve on a pipe leading back to No. 3 opened, while
the air valve is slightly open. The liquor from the filter is thus drawn back to
No. and the salts drained. If considered necessary they can be washed, for which
purpose a water stop cock is to be opened and water let into the rose. After the
salts have been drained, the valve leading to No. 3 and the water valve are closed
again, and the manhole opened for the removal of the salts. Then it is closed

page_text: again and the slide valve opened. so that
the settling of the salts in the filter
commences again. If the liquor which is to be evaporated contains several salts,
the composition of the precipitates in the various apparatus will be different, and so a
separation of the various salis can be effected.
Dated this Fifth day of April 1887.
WM. P. THOMPSON & Co.,
OF 6, Lord Street, Liverpool,
Agents for the Applicant.
COMPLETE SPECIFICATION (AMENDED).
Improvements in the Evaporating of Liquors Containing Salts
and in the Separation of those Salts.
A communication from abroad by Doctor SIGISMUND Pick, of Szczakowa, in
Galicia.
1, GEORGE ISAAC JAMES WELLS, of 41, Francis Terrace, Victoria Park, in the
County of Middlesex, Manufacturing Chemist, 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:—
The apparatus to be described hereafter is based upon the same principle as the
so-called Rillieux (or triple effect) apparatus, which as a rule is in use almost in every
sugar works.
While such apparatus is sometimes applied in other works for the
evaporation of clear liquors up to a certain strength, it is not applied for the evapora-
tion of liquors, from which salts are precipitated in the course of the evaporation, in
consequence of the difficulty of separating these salts from the liquor during the
evaporation, and of keeping the process as a continuous one. The new apparatus
does away with this difficulty, and offers some other advantages besides.
The principle of the Rillieux apparatus may be taken as well known; shortly it
may be described as the utilization of the latent heat of the steam in connection with
the lowering of the boiling point, by employing a pressure below the ordinary atmo-
spheric one. In such way one is enabled to keep up an energetic evaporation of a
liquor, having a high boiling point, by means of the ordinary exhaust steam from
engines, and to use over the steam so produced for the evaporation of another portion
of the same liquor and so ou.
The invention is best described by aid of the accompanying drawings in which:-
Figure is an elevation partly in section.
-

page_text: Figure
a plan, and
•
Figure a transverse elevation partly in section.
In these are boilers (preferably three in number and vertical, but other
forms may do) connected together as in the usual Rillieux apparatus. Each of these
has two preferably horizontal diaphragm tube plates A, A' occupying the entire cross
sectional area or nearly so, so as to enclose a central chamber A for heating steam,
and from one tube plate to the other I insert a number of tubes A connecting the
pari above the chamber with the part beneath. Into the tube chamber in No. the
steam from a boiler or other source is passed by means of a pipe and valve F and into
each of the others, the steam from the previous apparatus Nos. ¹ and a² respectively
is passed by means of pipes G G the steam from the last boiler is carried by
pipe G to condenser and air pump H. The boilers below the steam chamber are pre-
ferably in the form of a funnel B with a sluice valve C at bottom, and below this in
each case the vacuum filter D is fixed, hereafter described. Each of the two first.
steain heating chambers has a pipe not shown leading to a condenser, and air pump
(to exhaust non-condensable gases), reducing valves can be placed on these pipes or
Some of them if desired, to regulate the pressure, or other well known means, such as
different heights in a column of water, can be used for the same purpose.
The action of these triple-effect boilers is as follows:-
The three boilers being filled to usual water line the steam, either direct steam from
boilers or exhaust steam from engines, enters No. steam heating chamber through
the valve F, and passes round the tubes, heating the same, and the liquor contained
therein. The steam as it condeuses is led off by a steam trap from boiler No. ¹,
and from boilers Nos. 2 and 3, by pumps standing below the level. Between the
pumps and the steam chambers, collecting vessels are inserted. None of these traps,
pumps,and collecting vessels are shown in the drawings.it being unnecessary, they being
of the ordinary description. The steam evaporated from No. a enters the steam
heating chamber of No. , and that of No. enters the chamber of No. No.
boiler is connected on the top through a pipe G2 having a separator (where the
particles of the liquor carried away by the steam are separated), and also with a con-
denser and vacuum pump H. A strong vacuum is so formed in No. boiler by the
condensation of the steam and by the pump. Consequently the liquor therein boils
at a very low temperature. The heating of No. is effected by the steam coming
from No. 2, passing round the iuhes in the same manner as in No. a. Through this
condensation of the steam a vacuum is formed in No. ², and the boiling point
lowered. In No. the liquor is heated through the evaporation of the liquor in
No.
The condensation of this steam in No. forms a vacuum therein, and
consequently lowers the boiling point there. Therefore the highest temperature of
the liquor exists in No. a boiler, and the lowest in No. , while the strongest vacuum
is in No. 3, and the weakest in No. a. A most energetic evaporation is obtained in
this way. The liquor passes in the same manner as the steam from No, a to No, a²,
and from No. ² to No. 3. It enters No. a through a valve K, and pipe K¹, either
it runs in from a higher reservoir through its own weight, or it is drawn in from a
lower one through the vacuum. The most concentrated liquor leaves No. 2 through
pipe and valve N, it goes in a closed reservoir, which is standing below the level
of No., and is connected through an air pipe with the condenser. As the same
it
vacuum is formed in this reservoir as in No. 3, the liquor runs into it by its own
weight, of course the speed of the liquor has to be regulated according to the
evaporation.
The separation of the salts, which are precipitated through and during the evapora-
tion, is effected in the following manner. No. 4, No. 2. and No. , have sluice
valves Cat their conical bottom parts as already described. With these sluice valves C,
vacuum filters D, E, below are connected. These filters consists of a top part D a
little conical and a cylindrical bottom part E. The filtering material (perforated
plates, wire gauze, cloth, and layers of minerals) is fixed between the two parts at V.
The top part has an air tap R, a water pipe P¹ ending in a rose P, and a man-hole UI
on the bottom. The bottom part has gauge glasses W, and is connected through the

page_text: These
pipe Q' with the top part of No. 2, as this apparatus has the strongest vacuum.
vacuum fillers are worked in the following manner. The sluice valve C is opened and
the filter filled with liquor. The precipitated salts drop through the opening of the
sluice valve in the filter, and rest on the filtering material V. When the top part D
of the filter is filled with salt. or nearly full, the sluice valve C is closed, and the
valve Q on a pipe Q leading back to No. is opened, while the air valve R is slightly
open. The liquor from the filter is thus drawn back to No. 3 and the salts drained. If
considered necessary they can be washed, for which purpose a water stop cock S is to
he opened, and water let into the rose P. After the salts have been drained, the valve
leading to No. 3, and the water valve S are closed again, and the man-hole C opened
for the removal of the salts. Then it is closed again and the sluice valve C opened.
so that the settling of the salis in the filter commences again. If the liquor, which
is to be evaporated, contains several salts, the composition of the precipitate in the
various apparatus will be different, and so a separation of the various salts can be
effected.
Having now particularly described and ascertained the nature of the said
invention, and in what mater the same is to be performed, as communicated to
me by my foreign correspondent. I declare that what I claim is:-
1. In the evaporation of liquors containing salts, the use or employment of with a
vacuum boiling apparatus. of a filter worked by aid of the vacuum maintained in
the said apparatus, substantially as described.
2. The employment or use for the purposes described, of vacuum boiling apparatus,
having two or more settling chambers, worked at different degrees of concentration.
and in such manner as to allow of the separation from each other, and from the
liquor, of salts precipitating at different points of concentration, substantially as
described and illustrated in the accompanying drawings.
8. The employment or use for the purposes herein described, of the apparatus or
plant taken as a whole, substantially as herein set forth and illustrated.
Dated this 5th day of January 1888.
WM. P. THOMPSON & Co.,
Of 6. Lord Street, Liverpool,
Patent Agents for the Applicant.

page_text: Date of Application, 6th Apr., 1887
Complete Left, 6th Jan., 1888
Complete Accepted, 6th Apr., 1888
I, GEORGE ISAAC JAMES WELLS of 41 Francis Terrace, Victoria Park, in the
County of Middlesex, Manufacturing Chemist, do hereby declare the nature of this
invention to be as follows:-
The apparatus to be described hereafter is based upon the same principle as the so
called Rillieux apparatus, which as a rule is in use almost in every beet sugar works..
While such apparatus is sometimes applied in other works for the evaporation of clear
liquors up to a certain strength, it is not applied for the evaporation of liquors, from
which salts are precipitated in the course of the evaporation in consequence of the
difficulty of separating these salts from the liquor during the evaporation and of
keeping the process as a continuous one. The new apparatus does away with this
difficulty and offers some other advantages besides.
The principle of the Rillieux apparatus may be taken as well known; shortly it'
may be described as the utilisation of the latent heat of the steam in connection with
the lowering of the boiling point by employing a pressure below the ordinary atmo-
spheric one. In such way one is enabled to keep up an energetic evaporation of a
liquor having a high boiling point by means of the ordinary exhaust steam from.
engines and to use over the steam so produced for the evaporation of another portion
of the same liquor and so on.
In carrying out the invention, I form three (or more) boilers, (preferably vertical,
but other forms may do) connected together as in the usual triple-effect apparatus.

page_text: Each of these has two preferably horizontal diaphragm tube plates occupying the
entire cross sectional area or nearly so, so as to enclose a central chamber for heating
steam, and from one tube plate to the other, I insert a number of tubes connecting the
part above the chamber with the part beneath. Into the tube chamber in No. I the
steam from a boiler or other source is passed, by means of a pipe and valve and into
each of the others the steam from the previous apparatus Nos. 1 and 2 respectively is
passed. The boilers below the steam chamber are preferably funnel shaped with a
slide valve at bottom and below this in each case the vacuum filter is fixed hereafter
described. Each of the steam heating chambers has a pipe leading to a condenser and
air pump (to exhaust the water and non-condensible gases), reducing valves can be
placed on these pipes or some of them if desired to regulate the pressure, or other
means, such as different heights in a column of water can be used for the same
purpose.
The action of these triple effect boilers is as follows:-
The three boilers being filled to usual water line, the steam either direct steam from
boilers or exhaust steam from engines enters No. 1 steam heating chamber through the
valve, and passes round the tubes heating the same and the liquor contained therein.
The steam as it condenses is led off to the condenser by the pipe already described.
The steam evaporated from No. 1 enters the steam heating chamber of No. 2 and that
of No. 2 enters the chamber of No. 3. No. 3 boiler is connected on the top through
a pipe with a separator (where the particles of the liquor carried away by the steam
are separated) and also with a condenser and vacuum pump. A strong vacuum is so
formed in No. 3 boiler by the condensation of the steam and the pump. Consequently
the liquor therein boils at a very low temperature. The heating if No. 3 is effected
by the steam coming from No. 2 passing round the tubes in the same manner as in
No. 1. Through this condensation of the steam a vacuum is formed in No. 2 and the
boiling point lowered. In No. 2 the liquor is heated through the evaporation of the
liquor in No. 1. The condensation of this steam in No. 2 forms a vacuum therein,
and consequently lowers the boiling point there. Therefore the highest temperature
of the liquor exists in No. 1 boiler, and the lowest in No. 3, while the strongest
vacuum is in No. 3 and the weakest in No. 1. A most energetic evaporation is
obtained in this way. The liquor passes in the same manner as the steam from No. 1
to No. 2, from No. 2 to No. 3. It enters No. 1 through a valve and pipe, either it
runs in from a higher reservoir through its own weight, or it is drawn in from a
lower one through the vacuum. The most concentrated liquor leaves No. 3 through
a pipe and valve, it goes in a closed reservoir, which is standing below the level of
No. 3 and is connected through an air pipe with the condenser. As the same vacuum
is formed in this reservoir as in No. 3, the liquor runs into it by its own weight, of
course the speed of the liquor has to be regulated according to the evaporation.
.
The separation of the salts, which are precipitated through and during the evapora-
tion, is effected in the following manner. No. 1 No. 2 & No. 3 have slide valves at
their conical bottom parts as already described. With these slide valves, vacuum
filters below are connected. These filters consist of a top part, a little conical and a
cylindrical bottom part. The filtering material (perforated plates, wire, gauze, cloth'
layers of minerals) is fixed between the two parts. The top part has an air tap a
water pipe ending in a rose and a man hole on the bottom. The bottom part has
gauge glasses and is connected through the pipe with the top part of No. 3, as this
apparatus has the strongest vacuum. These vacuum filters are worked in the following
manner. The slide valve is opened and the filter filled with liquor. The precipi-
tated salts drop through the opening of the slide valve in the filter and rest on the
filtering material: When the top part of the filter is full with salt or nearly full, the
slide valve is closed and the valve on a pipo leading back to No. 3 opened, while
the air valve is slightly open. The liquor from the filter is thus drawn back to
No: 3 and the salts drained. If considered necessary they can be washed, for which
purpose a water stop cock is to be opened and water let into the rose. After the'
salts have been drained, the valve leading to No. 3 and the water valve are closed
again, and the manhole opened for the removal of the salts. Then it is closed

page_text: again and the slide valve opened, so that the settling of the salts in the filter
commences again. If the liquor which is to be evaporated contains several salts,
the composition of the precipitates in the various apparatus will be different, and so a
separation of the various salts can be effected.
T
רד
Improvements in the Evaporating of Liquors Containing Salts and
in the Separation of those Salts.
A communication, from abroad by Doctor SIGISMUND PICK, of Szczakowa, in
Galicia.
I, GEORGE ISAAC JAMES WELLS of 41, Francis Terrace, Victoria Park in the
County of Middlesex, Manufacturing Chemist, 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:-
:
The apparatus to be described hereafter is based upon the same principle as the
so-called Rillieux (or triple effect) apparatus, which as a rule is in use almost in every
sugar works. While such apparatus is sometimes applied in other works for the
evaporation of clear liquors up to a certain strength, it is not applied for the evapora-
tion of liquors, from which salts are precipitated in the course of the evaporation, in
consequence of the difficulty of separating these salts from the liquor during the
evaporation, and of keeping the process as a continuous one.
The new apparatus
does away with this difficulty, and offers some other advantages besides.
The principle of the Rillieux apparatus may be taken as well known; shortly it
may be described as the utilization of the latent heat of the steam in connection with
the lowering of the boiling point, by employing a pressure below the ordinary atmo-
spheric one. In such way one is enabled to keep up an energetic evaporation of a
liquor, having a high boiling point, by means of the ordinary exhaust steam from
engines, and to use over the steam so produced for the evaporation of another portion
of the same liquor, and so on.
The invention is best described by aid of the accompanying drawings in which;—
Figure 1. is an elevation partly in section.

page_text: Figure 2 a plan, and
Figure 3 a transverse elevation partly in section.
In these a', a', a are boilers (preferably three in number and vertical, but other
forms may do) connected together as in the usual Rillieux apparatus. Each of these
has two preferably horizontal diaphragm tube plates A, A¹ occupying the entire cross
sectional area or nearly so, so as to enclose a central chamber A for heating steam,
and from one tube plate to the other I insert a number of tubes A³ connecting the
part above the chamber with the part beneath. Into the tube chamber in No. the
steam from a boiler or other source is passed by means of a pipe and valve F and into
each of the others, the steam from the previous apparatus Nos. a¹ and a² respectively
is passed by means of pipes G' G₁, the steam from the last boiler a³ is carried by
pipe G to condenser and air pump H. The boilers below the steam chamber are pre-
ferably in the form of a funnel B with a sluice valve at bottom, and below this in
each case the vacuum filter D is fixed, hereafter described. Each of the two first
steam heating chambers has a pipe not shown leading to a condenser, and air pump
(to exhaust non-condensable gases), reducing valves can be placed on these pipes or
some of them if desired, to regulate the pressure, or other well known means, such as
different heights in a column of water, can be used for the same purpose.
The action of these triple-effect boilers is as follows:
The three boilers being filled to usual water line the steam, either direct steam from
boilers or exhaust steam from engines, enters No. a steam heating chamber through
the valve F, and passes round the tubes, heating the same, and the liquor contained
therein. The steam as it condenses is led off by a steam trap from boiler No. a³,
and from boilers Nos. a² and a³, by pumps standing below the level. Between the
pumps and the steam chambers, collecting vessels are inserted. None of these traps,
pumps, and collecting vessels are shown in the drawings, it being unnecessary, they being
of the ordinary description. The steam evaporated from No. a enters the steam
heating chamber of No. 2, and that of No. a enters the chamber of No. a³. No. a³
boiler is connected on the top through a pipe G2 having a separator G (where the
particles of the liquor carried away by the steam are separated), and also with a con-
denser and vacuum pump H. A strong vacuum is so formed in No. a boiler by the
condensation of the steam and by the pump. Consequently the liquor therein boils
at a very low temperature. The heating of No. a is effected by the steam coming
from No. a, passing round the tubes in the same manner as in No. a'. Through this
condensation of the steam a vacuum is formed in No. a', and the boiling point
lowered. In No. a the liquor is heated through the evaporation of the liquor in
No. a. The condensation of this steam in No. a² forms a vacuum therein, and
consequently lowers the boiling point thore. Therefore the highest temperature of
the liquor exists in No. a' boiler, and the lowest in No. a³, while the strongest vacuum
is in No. a, and the weakest in No. a¹. A most energetic evaporation is obtained in
this way. The liquor passes in the same manner as the steam from No. a¹ to No. a²,
and from No. a² to No. a³. It enters No. a' through a valve K, and pipe K', either
it runs in from a higher reservoir through its own weight, or it is drawn in from a
lower one through the vacuum. The most concentrated liquor leaves No. a³ through
a pipe N and valve N, it goes in a closed reservoir, which is standing below the level
of No. a³, and is connected through an air pipe with the condenser. As the same
vacuum is formed in this reservoir as in No. 3, the liquor runs into it by its own
weight, of course the speed of the liquor has to be regulated according to the
evaporation.
The separation of the salts, which are precipitated through and during the evapora-
tion, is effected in the following manner. No. a', No. 2, and No. a³, have sluice
valves C at their conical bottom parts as already described. With these sluice valves C,
vacuum filters D, E, below are connected. These filters consist of a top part I) a
little conical and a cylindrical bottom part E. The filtering material (perforated
plates, wire gauze, cloth, and layers of minerals) is fixed between the two parts at V.
The top part has an air tap R, a water pipe Pending in a rose P, and a man-hole U
on the bottom. The bottom part has gauge glasses W, and is connected through the

page_text: pipe Q with the top part of No. a³, as this apparatus has the strongest vacuum. These
vacuum filters are worked in the following manner. The sluice valve C is opened and
the filter filled with liquor. The precipitated salts drop through the opening of the
sluice valve in the filter, and rest on the filtering material V. When the top part D
of the filter is filled with salt or nearly full, tho sluice valve C is closed, and the
valve on a pipe Q leading back to No. a³ is opened, while the air valve R is slightly
open. The liquor from the filter is thus drawn back to No. a' and the salts drained. If
considered necessary they can be washed, for which purpose a water stop cock S is to
be opened, and water let into the rose P. After the salts have been drained, the valve
leading to No. 3, and the water valve S are closed again, and the man-hole U¹ opened
for the removal of the salts. Then it is closed again and the sluice valve C opened,
so that the settling of the salts in the filter commences again. If the liquor, which
is to be evaporated, contains several salts, the composition of the precipitate in the
various apparatus will be different, and so a separation of the various salts can be.
effected.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1. In the evaporation of liquors containing salts, the use or employment of a vacuum
boiling apparatus, of a filter worked by aid of the vacuum inaintained in the said
apparatus, substantially as described.
2. The employment or use for the purposes described, of vacuum boiling apparatus,
having two or more settling chambers, worked at different degrees of concentration,
and in such manner as to allow of the separation from each other, and from the
liquor, of salts precipitating at different points of concentration, substantially as
described.
3. The employment or use for the purposes herein described, of the apparatus or
plant taken as a whole, substantially as herein set forth and illustrated.
Dated this 5th day of January 1888