CA1266611A - Device for concentrating solutions - Google Patents
Device for concentrating solutionsInfo
- Publication number
- CA1266611A CA1266611A CA000504568A CA504568A CA1266611A CA 1266611 A CA1266611 A CA 1266611A CA 000504568 A CA000504568 A CA 000504568A CA 504568 A CA504568 A CA 504568A CA 1266611 A CA1266611 A CA 1266611A
- Authority
- CA
- Canada
- Prior art keywords
- vessel
- lowermost portion
- cooling jacket
- stirring means
- surrounded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/02—Crystallisation from solutions
- B01D9/04—Crystallisation from solutions concentrating solutions by removing frozen solvent therefrom
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/0004—Crystallisation cooling by heat exchange
- B01D9/0013—Crystallisation cooling by heat exchange by indirect heat exchange
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/004—Fractional crystallisation; Fractionating or rectifying columns
Abstract
ABSTRACT
The invention relates to a device for concentrating solutions by partly freezing-out solvent, consisting of a vessel surrounded laterally by an insulated cooling jacket, the vessel comprising a stirring means and a draining aperture at the bottom. The cooling jacket does not extend down to the lowermost portion of the vessel.
The lowermost portion of the vessel in which the stirring means and the draining aperture are accommodated, exter-nally comprises, preferably is surrounded by, a heating medium.
The invention relates to a device for concentrating solutions by partly freezing-out solvent, consisting of a vessel surrounded laterally by an insulated cooling jacket, the vessel comprising a stirring means and a draining aperture at the bottom. The cooling jacket does not extend down to the lowermost portion of the vessel.
The lowermost portion of the vessel in which the stirring means and the draining aperture are accommodated, exter-nally comprises, preferably is surrounded by, a heating medium.
Description
~66~1 Dl:R 0365 DE~II`,E FOR coNcENlR~-rlNG sol-urIoNs~
The i.nuen-ti.on relates -to a cleuice for concentrati.ng solutions by partly freezing~out the sol~ent.
Such a de~ice has been known for many decades already.
For exarnple, a deuice for and a rnethod of reco~ering cer-tain consti-tuents from solutions by solidifying the sol-uent and then separating the solid and liquid phases from each other are known from Nether].ands Patent Specification 38146 frorn 1936. In this rnanner, for example, salts can be separated from soluti.ons, or concentrates can be obtained from liquids, for exarnple, rnilk, by freezing-out the water.
The inuenti.on relates more in particular to the aboue -mentioned deuice for concentrating solutions, consisting of a uessel optionally closed on its upper side by a co~er and surrounded laterally by an insulated cooling jacket, the uesse]. comprising a stirring means and at the botttom a draining aperture, the cooling jacket not extendlng down to the lowerrrlost portion of the ~essel. Such a deuice is disclosed in Netherlands Patent Specification 88150. In this known freez.-ing uessel or freezing reseruoir an aqueous solution is cooled to a ternperature at which ice is formed. The ob~ect of the stirring means is to stir the liquid with the ice particles and to scrape the walls of the reseruoir so that the slurry of ice particles is kept in continuious mo-tion. ~ ~al~e through which the contents of the ~essel can be drained or remo~ed is pro~ided~in the bottom of the ~essel. ~ter draining the slurry of ice ~
particles from the reseruoir, it is prouided on a~sieùet ~ ~:
the slurry being kept~in motion. ~fter draining on the~
sie~e, the ice is separated from the concentrated liquid by centrifuging.
It will be obuious that the aboue method of concentra~
ting aqueous solutions is ~ery laborious and that~du~ring~
the processes of draining and centrifuging the lce.par ticles will partly go into solution again so that the ::
.
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ultimate result of the concentration is poor. Moreouer, ancl this is e~en a greater disad~antage, during stirring the slurry of ice particles considerable inclusion oF the constituents to be concentrated in the ice particles takes place both in the freezing reser~oir and on the sie~e, so that a considerable part of the constituents to be concen-trated remains behind in the centrifuge after centrifuging and hence is lost.
It is the object of the present in~ention to pro~ide a de~ice for concentrating solutions by partly freezing-out the sol~ent in which the abo~e disad~antages do not occur.
This object can be achie~ed by means of a de~ice as described hereinbefore, namely consisting of a ~essel op-tionally closed on its upper side by a co~er and surroun-ded laterally by an insulated cooling jacket, the ~esse].
comprising a stirring means and at the bottom a draining aperture, the cooling jacket not extending down to the lowerrnost portion of the ~essel, which de~ice is charac-terized according to the in~ention in that the lowcrmost portion of the vessel in which the stirring means and the draining aperture are present, externally comprises, pre-ferably is surrounded by, a heating medium. ~s a heating :
medium may be used, for example, a heating platej but a heating medium which completely surrounds the lowerrnost portion of the ~essel is to be preferred for a more uni-form heating of said lowermost portion. Examples of suit-able heating media completely surrounding said lowerrnost portion of the ~essel are electric heating jackets and ~,;.
heating baths; the contents of the latter can be kept at the desired temperature by means of a suitable heating de~ice. The contents of heating baths may be solicl or li-quid and preferably consist of a sufficiently heat-conduc.-~
ting material, for example, sand, glass beads or silica gel, or a liquid which is not or poorly ~olatile at the desired tempe~ature, for exarnple, a heatable oil, such ~1~661~
as si.li.corle o~.l., or a hi.gher pol~func-tional alcohol., such as glycerol.
For operati.ng the device according to the inuenti.on, the solution to be concentrated is introduced into the ~essel after its draining aperture has been closed. ~
cooling rnediurn is then passed through the cooling jacket.
The conventional cooling li.quicls, for example, a suitable alcohol, such as methanol, ethanol or isopropanol, are to be considered as a cooling medium. During the cooling pro~
cess, the solution in the lower portion of the ~essel is stirred and simultaneously kept at a slightly ele~ted ternperature, well o~er the -Freezing-point of the solution.
The sol~ent now begins to freeze out, starting on the side wall of the ~essel surrounded by the cooling jacket, while the solution in the lower portion of the vessel re~ains ligu.id. It has been found that with simultaneous heat.lng and stirring of the solution in the lower portion of the ~essel,~he sol~ent crystallizes out in a substantially pure state and deposits on the side wall of the ~essel as a frozen layer. The other constituents of the solution accumulate in the li~uicl in the lower portion of the vessel. When the concentration process has made suFficient progress, the concentrated solution may be drainecl:from : ;
said lower portion of the ~essel. Simultaneous stirring and heating of the solution which becomes more and more concentrated has pro~ed to be necessary to auoid the for~
mation of so-called wild crystal masses, i.e. of lumps or clusters of frozen soluent which ha~e not adhered to the si~e wall of the ~essel. Upon draining the concentrated :~
solution through the clraining aperture situated in the~ ~ :
heated lowermost portion of the ~essel, the crystallized : ;~
sol~ent remains adhered to the side wall of the ~essel;.
It will be ob~ious from the abo~e clescription that the~
concentrating of solutions in the de~ice according to the~
in~ention can be carried out in a particularly simple man- : :
, ner and can e~en be carrled out o~ernlght without super-~ision. ~t will moreo~er become apparent from the ensuing :, , ,.. -, ~ ~ : .
, : ' .. 'l : ,.: ::' " " ' , " ~ : . ;
~: . :.-. ~: - : :
:: . : : , " ' : :, .
~ i6~
specific exarnples that concentrating in the deuice according to the in~ention can be carried out ~ery effec-tiuely, i.e. that the quantity of sol~ent can be reduced ~ery consiclerabl~ with one single operation, for example, to 20% of the original ~olume, while simultaneously the constituents to be kept in the concentrate are found for the yreater part, for example, for at least 70%, in the concentrated liquid. Other ad~antages of the de~ice accor-ding to the inuention are that the processing for concen-trating the deuice requires only small preparation, giues hardly any chance of distwrbances and, when the concen~
tration rnight ne~ertheless fail, can be repeated ~ery simply. In -the latter case, the frozen sol~ent is thawed again, for example, by passing a heating liquid through the cooling jacket, after which the process may start again.
The de~ice according to the in~ention serues in par-ticular for concentrating aqueous solutions, but solutions of other solvents or mixtures of sol~ents, for example water with a water-rniscible sol~ent like methanol, ethanol or acetone, can also be concentrated by means oF the de-:
uice according to the in~ention. The ternperature of the cooling medium to be passed through the cooling j.acket : :
should, of course, be matched to the freezing-point of the~ ;~
soluent or mixture of sol~ents use~
Uarious body liquids, for example, urine, lumbal fluid or blood plasma, can be concentrated by means of the de~
~ice according to the inuention. ~s a result of this it is~
possible to detect and determine, e~en isolate, traces of ~ w rnedicines and metabolites hereof in these liquids. How~
e~er, the de~ice according to the in~ention is meant not only for pharmaceutical or clinical use, but it rnay also :~
be used in all the other fields where analyses ha~e to be :carried out or concentration is desired, for example,~ in:
th~e analysis oF drain~water, drinking water, rain water,: ~ :
soil water and surface water, both quantitati~ely:and ~ ~
, -:
. ,:
~2~6~
quali.ta-ti~ely, in the detection, determination and iso].a~-tion of, for exarnple, pesticides and metabolites thereof in extracts of, ~or example, crops and soil, in soil water and in surface water, and in concentrating waste liquids including waste liquids of bioindustries.
The de~ice according to the in~ention is preferably constructed in such manner that the diameter of the lower-most portion of the ~essel decreases towards the bottom until a diarneter has been reached which is just large enough for the stirring rneans to operate satisfactorlly.
~s a result of such a shape, efficient stirring an~
heating of said lowerrnost portion is promoted, while after concentration the concentrated liquid can more easily be drained from the draining aperture in the bottom.
Upon cooling the solution in the deuice according to the in~ention it is of importance that during the freezing-out process the sol~ent can ~ery quietly deposit on the side wall of the ~essel and can from there ~reeze up inwardly without, during the crystal formation, inclu- ~ :
sion of other constituents occurring and/or sol~ent crys-tals or conglo~erates hereof landing in the concentrated liquid. It is therefore desirable for the solution to be ::
not mo~ed at the area where the sol~ent is to crystal~lize out. Consequently, a so-called magnetic stirrer which can ::
impart a rotating mo~ement from outside to the stirring rneans, in this case a rod-shaped, fin-shaped or cross~
-shaped body ha~ing a metal core, is excellently suitable to keep the heated liquid in the lower portion of the ~essel in motion. The said magnetic stirrer is arra`nged~
below the ~essel and, if it comprises electric he~ati:ng,:~
can,~ for example, simultaneously ensure the heating of the heating bath which is preferably used.
When the concentrating process is continued, the con-tents of the ~essel, dependent on the height of the ves-sel, may freeze up entirely on the upper side. In that case, in order to enable the draining of the concé~ntrated :~
:
,~
..: - -. .,, ::
.
liquid after cornpletion of the concentrating, an aeration tube is necessary whose one end opens into the lowerrnost portion of the uessel and whose other end communi.cates with the outer air. Such an aeration tube hence is gene-rally highly desirable to facilitate concentration to, for example, less than 50% of the original liquid.
In order to stimulate cyrstallization of the soluent on the side wall of the uessel surrounded by the cooling jacket, the uessel internally preferably cumprises crys-tallization nuclei. Suitable crystallization nuclei for the soluent are formecl by a jacket o~ gauze, preferably a synthetic rnaterial gauze, for exarnple nylon gauze, which jacket is placed just against or at a short distance from the side wall of the uessel.
The inuention will now be described in greater detail with reference to a preferred embodiment which is shown in the drawings. The operation oF the deuice according to the inuention will furthermore be illustrated with reference to a few examples.
Figure 1 is a longitudinal sectional uiew of a deuice according to the inuention, and Figures 2, 3, 4, and 5 are ~ sectional ~iews o~
the same deuice, now in operation during the freezing pro-cess.
The deuice shown in Figure 1 comprises a glass uessèl 10 hauing a glass cooling jacket 1 through which an orga-nic liquid (for example, isopropanol, ethanol or metha-~ :
nol) cooled by a cooling deuice (cryostat~ at a tempera~
ture of 253-263 K is circulated by pumping. The cool1ng jacket is insulated by means of a second, euacuated, ~acket 2 which is closed by means of a cock 11. The aqueous solution 8 to be concentrated is present in the interior of the uessel. The uessel is closed by means of a couer 9 through which an aeration tube 7 extends down into the bottom of the sol~tion. The aeration tube is closed at its upper end by means of a co~k or stopper 12. The liquld ;'~
, :, : ,..
, :: -~æ~,6l~, DIR ~3~5 to be concentrated can be stirred by means of a stirrin~rod (stirring flea) 5 which is rotated by means o~ a mag-netic stirrer not shown in the drawings. The draining aper_,ture 13 of the ~essel cormnunicates with a tube 6 which is closed by means of a cock 14 and is rotatable at 15. The taperi~g lower portion 16 of the ~essel is not surrounded by the cooling jacket but is present in a heating bath 4 which is filled with sand. ~ jacket 3 of nylon gauze which ser~es as crystallization nuclei for the ice crystals is present internally against the side wall of the vessel.
- During operation of the de~ice shown in Figure 1, the solution to be concentrated is cooled by the coolin~
guid and starts freezing at the side wall surrounded by the cooling jacket. Simultaneously, the liquid in the lower portion of the ~essel is kept at an ele~ated tempe-rature b~ means of the heating bath and is stirred by means of the magnetic stirrer. Figure 2 shows the situa-tion after cooling ~or 0-2 hours, dependent on the dimen-sions of the uessel, the temperature of the cooling medium and the nature of the solution to be concentrated. The layer of ice begins t~ grow, first at the wall. Figure 3 shows the situation after cooling for 3-8 hours; the layer of ice grows thicker. When the solution becomes more:con-centrated, the freezing point drops. ~ stronger coo1ing is ;:
necessary in order to be able to continue the freezing process. Figure 4 shows the situation in which the upper ~:~
side of the liquid is entirely frozen up. This sltuatlon is reached after 9-24 hours. In the situation shown in:: ~ ~
Figure 5 the desired concentration has been completed;~ ~:
this~situation has been reached 25-48 hours after the be- :
ginning of the cooling process. ~fter opening the:cock~or stopper 12 of the aeration tube 7, the draining tube 6 is turned through approximately 180~ about the Fulcrum~po1nt 15, a~ter which the cock 14 is opened. The concentrated ~ ::
liquid may now be drained. : : ~
., ..... . ,. ,~......... .. . . ..
:. .... , ~: -:, . : ,.~-- ~'- .
. . .. ~. ~ , For illustrati.on, a few examples of a freeze concen-trat.ion i.n the device described hereinbefore will now be describecl, (a) ~ quantity of 4'-chloro-5-methoxy valerophenone (E)-0-(2-aminoethyl)oxime fumarate (1:1) (Clouoxamine) was administered to a hamster, which substance was radioacti-uely labelled with 14C. The administered dose of the pharmacon was 36 mg per kg of body weight~ ~fter admini-stration, the hamster's urine was collected. Totally 1230 ml of urine were concentrated to 290 ml by means of the aboue~describecl freeze concentration process. 70% of the radioactiuity present in the collected quantity of urine were founcl in the concentrate.
(b) ~ quantity of 0.25 mg per kg of body weight of 14C-labelled l-cyclohexyl 4 Cethyl(p methoxy~x methyl phenethyl)amino~ butanone hydrochloride (Secouerine) were administerecl to a human being. ~fter administration the urine was collected. Totally 1700 ml of urine were concentrated to 310 ml by means of the aboue described freeze-concentration process. 86% Of the radioactiuity present in the collected quantity of urine were found in the concentrate. .. :
:
,: . ,~ :., ~
' " ~ ' :.
-
The i.nuen-ti.on relates -to a cleuice for concentrati.ng solutions by partly freezing~out the sol~ent.
Such a de~ice has been known for many decades already.
For exarnple, a deuice for and a rnethod of reco~ering cer-tain consti-tuents from solutions by solidifying the sol-uent and then separating the solid and liquid phases from each other are known from Nether].ands Patent Specification 38146 frorn 1936. In this rnanner, for example, salts can be separated from soluti.ons, or concentrates can be obtained from liquids, for exarnple, rnilk, by freezing-out the water.
The inuenti.on relates more in particular to the aboue -mentioned deuice for concentrating solutions, consisting of a uessel optionally closed on its upper side by a co~er and surrounded laterally by an insulated cooling jacket, the uesse]. comprising a stirring means and at the botttom a draining aperture, the cooling jacket not extendlng down to the lowerrrlost portion of the ~essel. Such a deuice is disclosed in Netherlands Patent Specification 88150. In this known freez.-ing uessel or freezing reseruoir an aqueous solution is cooled to a ternperature at which ice is formed. The ob~ect of the stirring means is to stir the liquid with the ice particles and to scrape the walls of the reseruoir so that the slurry of ice particles is kept in continuious mo-tion. ~ ~al~e through which the contents of the ~essel can be drained or remo~ed is pro~ided~in the bottom of the ~essel. ~ter draining the slurry of ice ~
particles from the reseruoir, it is prouided on a~sieùet ~ ~:
the slurry being kept~in motion. ~fter draining on the~
sie~e, the ice is separated from the concentrated liquid by centrifuging.
It will be obuious that the aboue method of concentra~
ting aqueous solutions is ~ery laborious and that~du~ring~
the processes of draining and centrifuging the lce.par ticles will partly go into solution again so that the ::
.
:
~: : :: :
~:, . ; ; - , i61~
ultimate result of the concentration is poor. Moreouer, ancl this is e~en a greater disad~antage, during stirring the slurry of ice particles considerable inclusion oF the constituents to be concentrated in the ice particles takes place both in the freezing reser~oir and on the sie~e, so that a considerable part of the constituents to be concen-trated remains behind in the centrifuge after centrifuging and hence is lost.
It is the object of the present in~ention to pro~ide a de~ice for concentrating solutions by partly freezing-out the sol~ent in which the abo~e disad~antages do not occur.
This object can be achie~ed by means of a de~ice as described hereinbefore, namely consisting of a ~essel op-tionally closed on its upper side by a co~er and surroun-ded laterally by an insulated cooling jacket, the ~esse].
comprising a stirring means and at the bottom a draining aperture, the cooling jacket not extending down to the lowerrnost portion of the ~essel, which de~ice is charac-terized according to the in~ention in that the lowcrmost portion of the vessel in which the stirring means and the draining aperture are present, externally comprises, pre-ferably is surrounded by, a heating medium. ~s a heating :
medium may be used, for example, a heating platej but a heating medium which completely surrounds the lowerrnost portion of the ~essel is to be preferred for a more uni-form heating of said lowermost portion. Examples of suit-able heating media completely surrounding said lowerrnost portion of the ~essel are electric heating jackets and ~,;.
heating baths; the contents of the latter can be kept at the desired temperature by means of a suitable heating de~ice. The contents of heating baths may be solicl or li-quid and preferably consist of a sufficiently heat-conduc.-~
ting material, for example, sand, glass beads or silica gel, or a liquid which is not or poorly ~olatile at the desired tempe~ature, for exarnple, a heatable oil, such ~1~661~
as si.li.corle o~.l., or a hi.gher pol~func-tional alcohol., such as glycerol.
For operati.ng the device according to the inuenti.on, the solution to be concentrated is introduced into the ~essel after its draining aperture has been closed. ~
cooling rnediurn is then passed through the cooling jacket.
The conventional cooling li.quicls, for example, a suitable alcohol, such as methanol, ethanol or isopropanol, are to be considered as a cooling medium. During the cooling pro~
cess, the solution in the lower portion of the ~essel is stirred and simultaneously kept at a slightly ele~ted ternperature, well o~er the -Freezing-point of the solution.
The sol~ent now begins to freeze out, starting on the side wall of the ~essel surrounded by the cooling jacket, while the solution in the lower portion of the vessel re~ains ligu.id. It has been found that with simultaneous heat.lng and stirring of the solution in the lower portion of the ~essel,~he sol~ent crystallizes out in a substantially pure state and deposits on the side wall of the ~essel as a frozen layer. The other constituents of the solution accumulate in the li~uicl in the lower portion of the vessel. When the concentration process has made suFficient progress, the concentrated solution may be drainecl:from : ;
said lower portion of the ~essel. Simultaneous stirring and heating of the solution which becomes more and more concentrated has pro~ed to be necessary to auoid the for~
mation of so-called wild crystal masses, i.e. of lumps or clusters of frozen soluent which ha~e not adhered to the si~e wall of the ~essel. Upon draining the concentrated :~
solution through the clraining aperture situated in the~ ~ :
heated lowermost portion of the ~essel, the crystallized : ;~
sol~ent remains adhered to the side wall of the ~essel;.
It will be ob~ious from the abo~e clescription that the~
concentrating of solutions in the de~ice according to the~
in~ention can be carried out in a particularly simple man- : :
, ner and can e~en be carrled out o~ernlght without super-~ision. ~t will moreo~er become apparent from the ensuing :, , ,.. -, ~ ~ : .
, : ' .. 'l : ,.: ::' " " ' , " ~ : . ;
~: . :.-. ~: - : :
:: . : : , " ' : :, .
~ i6~
specific exarnples that concentrating in the deuice according to the in~ention can be carried out ~ery effec-tiuely, i.e. that the quantity of sol~ent can be reduced ~ery consiclerabl~ with one single operation, for example, to 20% of the original ~olume, while simultaneously the constituents to be kept in the concentrate are found for the yreater part, for example, for at least 70%, in the concentrated liquid. Other ad~antages of the de~ice accor-ding to the inuention are that the processing for concen-trating the deuice requires only small preparation, giues hardly any chance of distwrbances and, when the concen~
tration rnight ne~ertheless fail, can be repeated ~ery simply. In -the latter case, the frozen sol~ent is thawed again, for example, by passing a heating liquid through the cooling jacket, after which the process may start again.
The de~ice according to the in~ention serues in par-ticular for concentrating aqueous solutions, but solutions of other solvents or mixtures of sol~ents, for example water with a water-rniscible sol~ent like methanol, ethanol or acetone, can also be concentrated by means oF the de-:
uice according to the in~ention. The ternperature of the cooling medium to be passed through the cooling j.acket : :
should, of course, be matched to the freezing-point of the~ ;~
soluent or mixture of sol~ents use~
Uarious body liquids, for example, urine, lumbal fluid or blood plasma, can be concentrated by means of the de~
~ice according to the inuention. ~s a result of this it is~
possible to detect and determine, e~en isolate, traces of ~ w rnedicines and metabolites hereof in these liquids. How~
e~er, the de~ice according to the in~ention is meant not only for pharmaceutical or clinical use, but it rnay also :~
be used in all the other fields where analyses ha~e to be :carried out or concentration is desired, for example,~ in:
th~e analysis oF drain~water, drinking water, rain water,: ~ :
soil water and surface water, both quantitati~ely:and ~ ~
, -:
. ,:
~2~6~
quali.ta-ti~ely, in the detection, determination and iso].a~-tion of, for exarnple, pesticides and metabolites thereof in extracts of, ~or example, crops and soil, in soil water and in surface water, and in concentrating waste liquids including waste liquids of bioindustries.
The de~ice according to the in~ention is preferably constructed in such manner that the diameter of the lower-most portion of the ~essel decreases towards the bottom until a diarneter has been reached which is just large enough for the stirring rneans to operate satisfactorlly.
~s a result of such a shape, efficient stirring an~
heating of said lowerrnost portion is promoted, while after concentration the concentrated liquid can more easily be drained from the draining aperture in the bottom.
Upon cooling the solution in the deuice according to the in~ention it is of importance that during the freezing-out process the sol~ent can ~ery quietly deposit on the side wall of the ~essel and can from there ~reeze up inwardly without, during the crystal formation, inclu- ~ :
sion of other constituents occurring and/or sol~ent crys-tals or conglo~erates hereof landing in the concentrated liquid. It is therefore desirable for the solution to be ::
not mo~ed at the area where the sol~ent is to crystal~lize out. Consequently, a so-called magnetic stirrer which can ::
impart a rotating mo~ement from outside to the stirring rneans, in this case a rod-shaped, fin-shaped or cross~
-shaped body ha~ing a metal core, is excellently suitable to keep the heated liquid in the lower portion of the ~essel in motion. The said magnetic stirrer is arra`nged~
below the ~essel and, if it comprises electric he~ati:ng,:~
can,~ for example, simultaneously ensure the heating of the heating bath which is preferably used.
When the concentrating process is continued, the con-tents of the ~essel, dependent on the height of the ves-sel, may freeze up entirely on the upper side. In that case, in order to enable the draining of the concé~ntrated :~
:
,~
..: - -. .,, ::
.
liquid after cornpletion of the concentrating, an aeration tube is necessary whose one end opens into the lowerrnost portion of the uessel and whose other end communi.cates with the outer air. Such an aeration tube hence is gene-rally highly desirable to facilitate concentration to, for example, less than 50% of the original liquid.
In order to stimulate cyrstallization of the soluent on the side wall of the uessel surrounded by the cooling jacket, the uessel internally preferably cumprises crys-tallization nuclei. Suitable crystallization nuclei for the soluent are formecl by a jacket o~ gauze, preferably a synthetic rnaterial gauze, for exarnple nylon gauze, which jacket is placed just against or at a short distance from the side wall of the uessel.
The inuention will now be described in greater detail with reference to a preferred embodiment which is shown in the drawings. The operation oF the deuice according to the inuention will furthermore be illustrated with reference to a few examples.
Figure 1 is a longitudinal sectional uiew of a deuice according to the inuention, and Figures 2, 3, 4, and 5 are ~ sectional ~iews o~
the same deuice, now in operation during the freezing pro-cess.
The deuice shown in Figure 1 comprises a glass uessèl 10 hauing a glass cooling jacket 1 through which an orga-nic liquid (for example, isopropanol, ethanol or metha-~ :
nol) cooled by a cooling deuice (cryostat~ at a tempera~
ture of 253-263 K is circulated by pumping. The cool1ng jacket is insulated by means of a second, euacuated, ~acket 2 which is closed by means of a cock 11. The aqueous solution 8 to be concentrated is present in the interior of the uessel. The uessel is closed by means of a couer 9 through which an aeration tube 7 extends down into the bottom of the sol~tion. The aeration tube is closed at its upper end by means of a co~k or stopper 12. The liquld ;'~
, :, : ,..
, :: -~æ~,6l~, DIR ~3~5 to be concentrated can be stirred by means of a stirrin~rod (stirring flea) 5 which is rotated by means o~ a mag-netic stirrer not shown in the drawings. The draining aper_,ture 13 of the ~essel cormnunicates with a tube 6 which is closed by means of a cock 14 and is rotatable at 15. The taperi~g lower portion 16 of the ~essel is not surrounded by the cooling jacket but is present in a heating bath 4 which is filled with sand. ~ jacket 3 of nylon gauze which ser~es as crystallization nuclei for the ice crystals is present internally against the side wall of the vessel.
- During operation of the de~ice shown in Figure 1, the solution to be concentrated is cooled by the coolin~
guid and starts freezing at the side wall surrounded by the cooling jacket. Simultaneously, the liquid in the lower portion of the ~essel is kept at an ele~ated tempe-rature b~ means of the heating bath and is stirred by means of the magnetic stirrer. Figure 2 shows the situa-tion after cooling ~or 0-2 hours, dependent on the dimen-sions of the uessel, the temperature of the cooling medium and the nature of the solution to be concentrated. The layer of ice begins t~ grow, first at the wall. Figure 3 shows the situation after cooling for 3-8 hours; the layer of ice grows thicker. When the solution becomes more:con-centrated, the freezing point drops. ~ stronger coo1ing is ;:
necessary in order to be able to continue the freezing process. Figure 4 shows the situation in which the upper ~:~
side of the liquid is entirely frozen up. This sltuatlon is reached after 9-24 hours. In the situation shown in:: ~ ~
Figure 5 the desired concentration has been completed;~ ~:
this~situation has been reached 25-48 hours after the be- :
ginning of the cooling process. ~fter opening the:cock~or stopper 12 of the aeration tube 7, the draining tube 6 is turned through approximately 180~ about the Fulcrum~po1nt 15, a~ter which the cock 14 is opened. The concentrated ~ ::
liquid may now be drained. : : ~
., ..... . ,. ,~......... .. . . ..
:. .... , ~: -:, . : ,.~-- ~'- .
. . .. ~. ~ , For illustrati.on, a few examples of a freeze concen-trat.ion i.n the device described hereinbefore will now be describecl, (a) ~ quantity of 4'-chloro-5-methoxy valerophenone (E)-0-(2-aminoethyl)oxime fumarate (1:1) (Clouoxamine) was administered to a hamster, which substance was radioacti-uely labelled with 14C. The administered dose of the pharmacon was 36 mg per kg of body weight~ ~fter admini-stration, the hamster's urine was collected. Totally 1230 ml of urine were concentrated to 290 ml by means of the aboue~describecl freeze concentration process. 70% of the radioactiuity present in the collected quantity of urine were founcl in the concentrate.
(b) ~ quantity of 0.25 mg per kg of body weight of 14C-labelled l-cyclohexyl 4 Cethyl(p methoxy~x methyl phenethyl)amino~ butanone hydrochloride (Secouerine) were administerecl to a human being. ~fter administration the urine was collected. Totally 1700 ml of urine were concentrated to 310 ml by means of the aboue described freeze-concentration process. 86% Of the radioactiuity present in the collected quantity of urine were found in the concentrate. .. :
:
,: . ,~ :., ~
' " ~ ' :.
-
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A device for concentrating solutions by partly freezing-out the solvent, consisting of a vessel optionally closed on its upper side by a cover and surrounded laterally by an insulated cooling jacket, the vessel comprising a stirring means and at the bottom a draining aperture, the cooling jacket not extending down to the lowermost portion of the vessel, characterized in that the lowermost portion of the vessel in which the stirring means and the draining aperture are present, externally comprises a heating medium.
2. A device as claimed in Claim 1, characterized in that the lowermost portion of the vessel is surrounded by a heating medium.
3. A device as claimed in Claim 1 or 2, characterized in that the lowermost portion of the vessel tapers towards the bottom until a bottom diameter has been reached which is just large enough to permit a ready operation of the stirring means.
4. A device as claimed in Claim 1 or 2, characterized in that the stirring means is a rod-shaped, fin-shaped or cross-shaped member comprising a metal core which can be rotated by means of a so-called magnetic stirrer.
5. A device as claimed in Claim 1 or 2, characterized in that the vessel comprises an aeration tube one end of which opens into the lowermost portion of the vessel and the other end communicates with the outer air.
6. A device as claimed in Claim 1, characterized in that the vessel comprises internally crystallization nuclei for the solvent on the side wall surrounded by the cooling jacket.
7. A device as claimed in Claim 6, characterized in that the crystallization nuclei for the solvent are formed by a jacket of gauze, preferably of a synthetic material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8500859 | 1985-03-25 | ||
| NL8500859 | 1985-03-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1266611A true CA1266611A (en) | 1990-03-13 |
Family
ID=19845728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000504568A Expired - Fee Related CA1266611A (en) | 1985-03-25 | 1986-03-20 | Device for concentrating solutions |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4697428A (en) |
| EP (1) | EP0196128B1 (en) |
| JP (1) | JPS61268301A (en) |
| AT (1) | ATE35381T1 (en) |
| CA (1) | CA1266611A (en) |
| DE (1) | DE3660343D1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1140312B1 (en) * | 1998-09-21 | 2009-07-22 | Howard E. Purdum | Methods and apparatus for processing blood plasma or blood plasma concentrate |
| JP4933115B2 (en) * | 2006-03-02 | 2012-05-16 | 水ｉｎｇ株式会社 | Waste water crystallization treatment equipment |
| DE102006032176A1 (en) * | 2006-07-12 | 2008-01-24 | Martin-Luther-Universität Halle-Wittenberg | Method for concentrating dissolved material comprises directionally separating out the solvent contained in the material by freezing until the required concentration is reached |
| JP5120958B2 (en) * | 2009-01-14 | 2013-01-16 | 株式会社東洋製作所 | Method for freeze concentration of solution |
| CN105658293A (en) * | 2013-08-29 | 2016-06-08 | 株式会社明治 | Production method for concentrated product using freeze-concentration method |
| US10139317B2 (en) * | 2015-10-30 | 2018-11-27 | South Dakota Board Of Regents | Methods and apparatuses for trace and ultratrace analysis |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE36389C (en) * | H. HABICH in Veckerhagen a. d. W | Method and apparatus for removing from the ice that portion which remains unfrozen when an aqueous liquid is frozen | ||
| US1865614A (en) * | 1928-08-16 | 1932-07-05 | Swenson Evaporator Company | Vacuum cooler |
| NL38146C (en) * | 1933-11-02 | |||
| US1991844A (en) * | 1934-06-07 | 1935-02-19 | Jones & Laughlin Steel Corp | Process of making chemically pure benzene |
| US2896418A (en) * | 1955-11-07 | 1959-07-28 | Union Carbide Corp | Method and apparatus of freeze dehydration |
| US3121627A (en) * | 1961-07-24 | 1964-02-18 | Water Process Corp | Method of purifying water by freezing |
| NL135664C (en) * | 1964-04-29 | |||
| GB1142864A (en) * | 1965-11-15 | 1969-02-12 | Ici Ltd | Crystallisation process |
| US3443393A (en) * | 1967-01-17 | 1969-05-13 | Moise Levy Goldberg | Triple point desalination system utilizing a single low pressure vessel and a gravity sea water feed |
| US3411309A (en) * | 1967-02-13 | 1968-11-19 | Ici Ltd | Fractional freeze separation apparatus and process |
| US3543531A (en) * | 1967-05-08 | 1970-12-01 | Clyde C Adams | Freeze refining apparatus |
| DE2138681A1 (en) * | 1971-08-03 | 1973-02-08 | Metallgesellschaft Ag | PROCESS FOR THE DECOMPOSITION OF MIXTURES BY RECTIFYING CRYSTALLIZATION |
| GB1500245A (en) * | 1976-08-25 | 1978-02-08 | Telkes M | Nucleating device and method of preparing same |
| US4296612A (en) * | 1980-06-18 | 1981-10-27 | Chicago Bridge & Iron Company | Freeze exchanger with removable tube liner |
-
1986
- 1986-03-03 AT AT86200320T patent/ATE35381T1/en active
- 1986-03-03 EP EP86200320A patent/EP0196128B1/en not_active Expired
- 1986-03-03 DE DE8686200320T patent/DE3660343D1/en not_active Expired
- 1986-03-20 CA CA000504568A patent/CA1266611A/en not_active Expired - Fee Related
- 1986-03-20 US US06/841,630 patent/US4697428A/en not_active Expired - Lifetime
- 1986-03-22 JP JP61062030A patent/JPS61268301A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| EP0196128A1 (en) | 1986-10-01 |
| JPS61268301A (en) | 1986-11-27 |
| DE3660343D1 (en) | 1988-08-04 |
| EP0196128B1 (en) | 1988-06-29 |
| ATE35381T1 (en) | 1988-07-15 |
| JPH0574401B2 (en) | 1993-10-18 |
| US4697428A (en) | 1987-10-06 |
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