CH380703A

CH380703A - Continuous extraction process with a solvent and device for implementing this process

Info

Publication number: CH380703A
Application number: CH1279361A
Authority: CH
Inventors: Baudet Pierre
Original assignee: Baudet Pierre
Priority date: 1961-11-04
Filing date: 1961-11-04
Publication date: 1964-08-14

Description

  

  
 



   Procédé d'extraction continue par un solvant et dispositif pour la mise en oeuvre de ce procédé
 Les extractions de solides par les extracteurs actuels se font soit par le type d'extraction dit discontinu, soit par le type d'extraction dit continu.



   Dans l'appareil extracteur de Soxhlet, qui est un exemple du premier type, la matière solide placée dans un réservoir reçoit goutte-à-goutte un solvant extracteur condensé dans un condenseur placé audessus du réservoir. Les vapeurs du solvant proviennent d'un ballon à distillation placé au-dessus du réservoir. Lorsque le solvant remplit le réservoir, un siphon s'amorce amenant le solvant à s'écouler dans le ballon de distillation où s'accumule peu à peu la substance extraite.



   Dans un appareil du second type, le fond du réservoir de l'appareil de Soxhlet est ouvert, et l'ouverture est masquée par un tampon de matière filtrante. Le procédé d'extraction est le mme que celui de l'appareil de Soxhlet, mais le solvant au lieu de revenir de façon discontinue dans le ballon de distillation après amorçage du siphon, s'écoule continuellement par le bas du réservoir à travers le tampon de matière filtrante.



   Ces deux types d'appareils ne répondent pas aux besoins de l'extraction industrielle parce que leur construction est compliquée, leur rendement souvent insuffisant et leur possibilité d'emploi très réduite.



   L'appareil en continu (2e type) qui se prte le mieux à une extraction industrielle est celui décrit par Applezweig (Ind. Eng. Chem. Annal. Ed. 16.472 1944). Dans cet appareil, le solvant chargé de l'extrait s'écoule par un trop-plein dans le ballon de distillation duquel partent les vapeurs qui viennent se condenser au-dessus du ballon d'extraction.



   Les inconvénients de cet appareil résident dans la complication de sa construction, dans le débit réduit de l'extraction, dans la difficulté d'effectuer une extraction aux   tempWratures    supérieures à la température ordinaire, dans le fait que le volume du solvant dans le ballon d'extraction est fixe et dans la difficulté d'y appliquer une vide partiel.



   Un extracteur industriel doit assurer:
 Une extraction complète dans le temps le plus court.



   Une réutilisation continue du volume du solvant initialement introduit dans l'extracteur.



   La possibilité d'effectuer des extractions à la température et à la pression désirées.



   La possibilité de travailler avec des volumes de solvant et des charges de matière solide très variables.



   Un extracteur industriel doit en outre tre de construction simple.



   La présente invention a précisément pour objet un procédé d'extraction continue par un solvant et un dispositif pour la mise en   oeuvre    de ce procédé permettant de remplir les conditions ci-dessus et d'obvier aux inconvénients cités.



   Le procédé est caractérisé en ce qu'on introduit la matière solide ou liquide dont on veut extraire un ou plusieurs constituants dans un premier réservoir, en ce que   l'on    remplit ce réservoir ainsi qu'un second réservoir relié au premier par un conduit, en ce qu'on soumet le solvant du second réservoir à une vaporisation, en ce que   l'on    condense ce solvant vaporisé et le fait s'écouler dans le premier réservoir, la solution du ou des constituants extraits formée dans le premier réservoir s'écoulant continuellement et irréversiblement, jusqu'à extraction complète, à travers ledit conduit dans le second réservoir pour rétablir le mme niveau de liquide dans les deux réservoirs.  



   Le dessin annexé représente, à titre d'exemple, une coupe en élévation d'une forme d'exécution du dispositif selon l'invention, destinée à l'extraction d'un ou plusieurs constituants d'une matière solide finement divisée. Cette forme d'exécution comprend un réservoir d'extraction 1 et un réservoir de distillation 2 dont les fonds communiquent par un conduit 3, pourvu d'un robinet à trois voies 4, et dont les parties supérieures sont reliées par un condenseur   5 ; un    filtre 6 termine le conduit 3 dans le réservoir 1, lequel est surmonté d'un condenseur à reflux 7.



   Des moyens de chauffage, non représentés au dessin, tels que par exemple des résistances électriques réglables, permettent d'élever la température du liquide contenu dans les réservoirs 1, 2 et dans le conduit 3.



   Le conduit 3, les condenseur 5, le filtre 6 et le condenseur à reflux 7 peuvent tre tous quatre de type amovible. Le condenseur 5 et le condenseur à reflux 7 sont de préférence à double paroi de refroidissement.



   Le filtre 6, destiné à retenir la matière solide divisée dans le réservoir 1, est constitué, par exemple, par une tubulure en verre, métal, matière plastique, céramique ou matière textile, percée de petits trous et entourée d'un manchon fait de textile ou d'un treillis métallique très fin.



   Dans une autre forme d'exécution, le filtre est remplacé par un tambour percé de petits trous et doublé intérieurement d'un manchon très perméable contenant la matière solide divisée. Le tambour fixé à une tige qui lui communique un mouvement de rotation alternatif plonge dans le liquide du réservoir 1.



   Le dispositif selon la forme d'exécution   repré-    sentée au dessin peut comporter un moyen destiné à agiter le liquide et la matière solide divisée dans le réservoir 1 afin d'accélérer l'extraction. Ce moyen peut consister par exemple en une pompe extérieure audit réservoir, comprenant un conduit courbe qui débouche par ses deux extrémités dans le réservoir 1 un peu au-dessus de son fond et en des points opposés, l'une desdites extrémités aspirant la solution et la matière solide divisée,   vautre    les refoulant en créant ragitation voulue.



   Pour mettre en action le dispositif ci-dessus, on introduit le solvant et la matière solide divisée, dont on veut extraire un ou plusieurs constituants, dans le réservoir 1, puis on porte à l'ébullition le solvant du réservoir 2; les vapeurs formées se condensant dans le condenseur 5, le solvant s'écoule rapidement et continuellement dans le réservoir 1.



  Par l'effet des vases communicants, la solution des substances extraites, formée dans le réservoir 1, s'écoule continuellement et irréversiblement à travers le filtre 6 et le conduit 3 dans le réservoir 2, jusqu'à extraction complète, c'est-à-dire jusqu'au moment où toutes les substances à extraire ont entièrement passé du réservoir 1 ou réservoir 2.



   L'extraction, que   l'on    contrôle par des prises de solvant au robinet 4, s'effectue à la température désirée ; si celle-ci est telle que la tension de vapeur soit trop élevée, on condense les vapeurs au moyen du condenseur à reflux 7.



   Lorsqu'à la température d'ébullition, sous pression ordinaire, les substances à extraire ou extraites sont altérées en raison de leur instabilité physique ou chimique, on abaisse la température d'ébullition du solvant en créant, à travers le condenseur à reflux 7, un vide partiel dans les réservoirs 1 et 2.



   Après extraction complète, on soutire l'extrait au moyen du robinet 4.



   Lorsque la matière soumise à l'extraction est liquide, on l'introduit en solution, dans un solvant léger, dans le réservoir 1, puis on vaporise un solvant lourd contenu dans le réservoir 2. Le solvant lourd condensé dans le condenseur 5 est dispersé dans le solvant léger au moyen par exemple, d'une poire vibrante; il s'y charge de la substance à extraire, se décante et retourne par le conduit 3 au réservoir 2.



   La vitesse d'évaporation du solvant, à son point d'ébullition sous pression ordinaire ou réduite, et la capacité de condensation du condenseur 5, conditionnent la rapidité du déplacement de la solution du réservoir 1 dans le réservoir 2 par le conduit 3, et par conséquent la rapidité de l'extraction.



   D'autre part l'agitation provoquée du solvant et de la matière solide divisée dans le réservoir 1 conditionne elle aussi la vitesse de l'extraction. Le chemin parcouru par les vapeurs dans le réservoir 2, de la surface du solvant à l'entrée du condenseur 5, doit tre le plus court possible, et ce réservoir ne doit pas présenter de surface refroidissante capable de condenser les vapeurs à reflux.



   Ce dispositif présente l'avantage d'une grande simplicité et d'un prix de revient relativement peu élevé.   I1    est utilisable selon ses dimensions dans un laboratoire ou industriellement et permet de traiter des quantités très variables de matière de départ par des quantités correspondantes très variables de solvant. On peut ainsi réaliser l'extraction rapide et complète de substances mme peu stables du point de vue physique ou chimique. Ce procédé est en outre économique parce qu'il permet une récupération et une réutilisation continuelle et totale du solvant d'extraction, il permet également d'extraire un solvant léger par un solvant lourd. Son application s'est en particulier montrée très avantageuse dans l'extraction de graisses, de tannins et d'alca  loïdes.   
 



   REVENDICATIONS
 1. Procédé d'extraction continue par un solvant, caractérisé en ce qu'on introduit la matière solide ou liquide dont on veut extraire un ou plusieurs constituants dans un premier réservoir, en ce que   l'on    remplit de solvant ce réservoir ainsi qu'un second réservoir relié au premier par un conduit, 

**ATTENTION** fin du champ DESC peut contenir debut de CLMS **.



   



  
 



   Continuous extraction process with a solvent and device for implementing this process
 Solids extractions by current extractors are carried out either by the so-called discontinuous type of extraction, or by the so-called continuous type of extraction.



   In the Soxhlet extractor apparatus, which is an example of the first type, the solid matter placed in a reservoir receives dropwise an extracting solvent condensed in a condenser placed above the reservoir. The solvent vapors come from a distillation flask placed above the tank. When the solvent fills the tank, a siphon is initiated causing the solvent to flow into the distillation flask where the extracted substance gradually accumulates.



   In an apparatus of the second type, the bottom of the reservoir of the Soxhlet apparatus is open, and the opening is masked by a pad of filter material. The extraction process is the same as that of the Soxhlet apparatus, but instead of returning intermittently to the distillation flask after priming of the siphon, continuously flows from the bottom of the tank through the buffer of filter material.



   These two types of apparatus do not meet the needs of industrial extraction because their construction is complicated, their efficiency often insufficient and their possibility of use very limited.



   The continuous device (2nd type) which lends itself best to industrial extraction is that described by Applezweig (Ind. Eng. Chem. Annal. Ed. 16.472 1944). In this apparatus, the solvent charged with the extract flows through an overflow into the distillation flask from which the vapors leave which condense above the extraction flask.



   The disadvantages of this apparatus lie in the complication of its construction, in the reduced flow rate of the extraction, in the difficulty of carrying out an extraction at temperatures above ordinary temperature, in the fact that the volume of the solvent in the flask d The extraction is fixed and in the difficulty of applying a partial vacuum to it.



   An industrial extractor must ensure:
 Complete extraction in the shortest time.



   Continuous reuse of the volume of the solvent initially introduced into the extractor.



   The ability to perform extractions at the desired temperature and pressure.



   The possibility of working with very variable volumes of solvent and loads of solid matter.



   An industrial extractor must also be of simple construction.



   The present invention specifically relates to a continuous extraction process using a solvent and a device for implementing this process making it possible to fulfill the above conditions and to obviate the cited drawbacks.



   The process is characterized in that the solid or liquid material from which one or more constituents is to be extracted is introduced into a first reservoir, in that this reservoir is filled as well as a second reservoir connected to the first by a pipe, in that the solvent of the second reservoir is subjected to vaporization, in that this vaporized solvent is condensed and made to flow into the first reservoir, the solution of the extracted constituent (s) formed in the first reservoir s' flowing continuously and irreversibly, until complete extraction, through said conduit in the second reservoir to restore the same liquid level in the two reservoirs.



   The accompanying drawing shows, by way of example, a sectional elevation of one embodiment of the device according to the invention, intended for the extraction of one or more constituents from a finely divided solid material. This embodiment comprises an extraction tank 1 and a distillation tank 2, the bottoms of which communicate via a conduit 3, provided with a three-way valve 4, and the upper parts of which are connected by a condenser 5; a filter 6 terminates the pipe 3 in the tank 1, which is surmounted by a reflux condenser 7.



   Heating means, not shown in the drawing, such as for example adjustable electrical resistors, make it possible to raise the temperature of the liquid contained in the reservoirs 1, 2 and in the duct 3.



   The conduit 3, the condenser 5, the filter 6 and the reflux condenser 7 can all be of the removable type. The condenser 5 and the reflux condenser 7 preferably have a double cooling wall.



   The filter 6, intended to retain the solid material divided in the tank 1, consists, for example, of a tube made of glass, metal, plastic, ceramic or textile material, pierced with small holes and surrounded by a sleeve made of textile or a very fine wire mesh.



   In another embodiment, the filter is replaced by a drum pierced with small holes and lined internally with a very permeable sleeve containing the divided solid material. The drum fixed to a rod which gives it an alternating rotational movement is immersed in the liquid in tank 1.



   The device according to the embodiment shown in the drawing may include a means for agitating the liquid and the divided solid material in the reservoir 1 in order to accelerate the extraction. This means may consist for example of a pump external to said reservoir, comprising a curved duct which opens at its two ends into the reservoir 1 a little above its bottom and at opposite points, one of said ends sucking in the solution and the divided solid matter, wallows, pushing them back, creating the desired agitation.



   To put the above device into action, the solvent and the divided solid matter, from which one or more constituents are to be extracted, are introduced into the tank 1, then the solvent in the tank 2 is brought to the boil; the vapors formed condensing in the condenser 5, the solvent flows rapidly and continuously into the tank 1.



  By the effect of the communicating vessels, the solution of the extracted substances, formed in the tank 1, flows continuously and irreversibly through the filter 6 and the pipe 3 in the tank 2, until complete extraction, that is, i.e. until the moment when all the substances to be extracted have completely passed from tank 1 or tank 2.



   The extraction, which is controlled by taking the solvent from tap 4, is carried out at the desired temperature; if this is such that the vapor pressure is too high, the vapors are condensed by means of the reflux condenser 7.



   When at the boiling temperature, under ordinary pressure, the substances to be extracted or extracted are altered due to their physical or chemical instability, the boiling temperature of the solvent is lowered by creating, through the reflux condenser 7, a partial vacuum in tanks 1 and 2.



   After complete extraction, the extract is withdrawn by means of the tap 4.



   When the material subjected to the extraction is liquid, it is introduced in solution, in a light solvent, into the tank 1, then a heavy solvent contained in the tank 2 is vaporized. The heavy solvent condensed in the condenser 5 is dispersed. in the light solvent by means of, for example, a vibrating pear; it loads the substance to be extracted there, settles and returns through line 3 to tank 2.



   The rate of evaporation of the solvent, at its boiling point under ordinary or reduced pressure, and the condensing capacity of the condenser 5, determine the rapidity of the movement of the solution from the tank 1 into the tank 2 through the line 3, and hence the speed of extraction.



   On the other hand the agitation caused by the solvent and the solid matter divided in the tank 1 also conditions the speed of the extraction. The path traveled by the vapors in the reservoir 2, from the surface of the solvent to the inlet of the condenser 5, must be as short as possible, and this reservoir must not have a cooling surface capable of condensing the vapors at reflux.



   This device has the advantage of great simplicity and a relatively low cost price. Depending on its dimensions, it can be used in a laboratory or industrially and makes it possible to treat very variable amounts of starting material with corresponding very variable amounts of solvent. It is thus possible to achieve the rapid and complete extraction of substances even unstable from a physical or chemical point of view. This process is moreover economical because it allows a continuous and total recovery and reuse of the extraction solvent, it also makes it possible to extract a light solvent by a heavy solvent. Its application has been shown in particular to be very advantageous in the extraction of fats, tannins and alkaloids.
 



   CLAIMS
 1. Continuous extraction process with a solvent, characterized in that the solid or liquid material from which one or more constituents is to be extracted into a first reservoir, in that this reservoir is filled with solvent as well as a second reservoir connected to the first by a conduit,

** ATTENTION ** end of DESC field can contain start of CLMS **.

Claims

** ATTENTION ** start of field CLMS can contain end of DESC **.

The accompanying drawing shows, by way of example, a sectional elevation of one embodiment of the device according to the invention, intended for the extraction of one or more constituents from a finely divided solid material. This embodiment comprises an extraction tank 1 and a distillation tank 2, the bottoms of which communicate via a conduit 3, provided with a three-way valve 4, and the upper parts of which are connected by a condenser 5; a filter 6 terminates the pipe 3 in the tank 1, which is surmounted by a reflux condenser 7.

Heating means, not shown in the drawing, such as for example adjustable electrical resistors, make it possible to raise the temperature of the liquid contained in the reservoirs 1, 2 and in the duct 3.

The conduit 3, the condenser 5, the filter 6 and the reflux condenser 7 can all be of the removable type. The condenser 5 and the reflux condenser 7 preferably have a double cooling wall.

The filter 6, intended to retain the solid material divided in the tank 1, consists, for example, of a tube made of glass, metal, plastic, ceramic or textile material, pierced with small holes and surrounded by a sleeve made of textile or a very fine wire mesh.

In another embodiment, the filter is replaced by a drum pierced with small holes and lined internally with a very permeable sleeve containing the divided solid material. The drum fixed to a rod which gives it an alternating rotational movement is immersed in the liquid in tank 1.

The device according to the embodiment shown in the drawing may include a means for agitating the liquid and the divided solid material in the reservoir 1 in order to accelerate the extraction. This means may consist for example of a pump external to said reservoir, comprising a curved duct which opens at its two ends into the reservoir 1 a little above its bottom and at opposite points, one of said ends sucking in the solution and the divided solid matter, wallows, pushing them back, creating the desired agitation.

To put the above device into action, the solvent and the divided solid matter, from which one or more constituents are to be extracted, are introduced into the tank 1, then the solvent in the tank 2 is brought to the boil; the vapors formed condensing in the condenser 5, the solvent flows rapidly and continuously into the tank 1.

By the effect of the communicating vessels, the solution of the extracted substances, formed in the tank 1, flows continuously and irreversibly through the filter 6 and the pipe 3 in the tank 2, until complete extraction, that is, i.e. until the moment when all the substances to be extracted have completely passed from tank 1 or tank 2.

The extraction, which is controlled by taking the solvent from tap 4, is carried out at the desired temperature; if this is such that the vapor pressure is too high, the vapors are condensed by means of the reflux condenser 7.

When at the boiling temperature, under ordinary pressure, the substances to be extracted or extracted are altered due to their physical or chemical instability, the boiling temperature of the solvent is lowered by creating, through the reflux condenser 7, a partial vacuum in tanks 1 and 2.

After complete extraction, the extract is withdrawn by means of the tap 4.

When the material subjected to the extraction is liquid, it is introduced in solution, in a light solvent, into the tank 1, then a heavy solvent contained in the tank 2 is vaporized. The heavy solvent condensed in the condenser 5 is dispersed. in the light solvent by means of, for example, a vibrating pear; it loads the substance to be extracted there, settles and returns through line 3 to tank 2.

The rate of evaporation of the solvent, at its boiling point under ordinary or reduced pressure, and the condensing capacity of the condenser 5, determine the rapidity of the movement of the solution from the tank 1 into the tank 2 through the line 3, and hence the speed of extraction.

On the other hand the agitation caused by the solvent and the solid matter divided in the tank 1 also conditions the speed of the extraction. The path traveled by the vapors in the reservoir 2, from the surface of the solvent to the inlet of the condenser 5, must be as short as possible, and this reservoir must not have a cooling surface capable of condensing the vapors at reflux.

This device has the advantage of great simplicity and a relatively low cost price. Depending on its dimensions, it can be used in a laboratory or industrially and makes it possible to treat very variable amounts of starting material with corresponding very variable amounts of solvent. It is thus possible to achieve the rapid and complete extraction of substances even unstable from a physical or chemical point of view. This process is moreover economical because it allows a continuous and total recovery and reuse of the extraction solvent, it also makes it possible to extract a light solvent by a heavy solvent. Its application has been shown in particular to be very advantageous in the extraction of fats, tannins and alkaloids.

CLAIMS 1. Continuous extraction process with a solvent, characterized in that the solid or liquid material from which one or more constituents is to be extracted into a first reservoir, in that this reservoir is filled with solvent as well as a second reservoir connected to the first by a conduit, in that the solvent of the second reservoir is subjected to vaporization, in that this vaporized solvent is condensed and made to flow into the first reservoir, the solution of or extracted constituents formed in the first reservoir flowing continuously and irreversibly, until complete extraction, through said duct in the second reservoir to restore the same liquid level in the two reservoirs.

II. Device for carrying out the method according to Claim I, characterized in that it comprises at least one extraction tank and a distillation tank, the bottoms of which communicate by a conduit and the upper parts of which are connected by at least a condenser.

SUB-CLAIMS I. Method according to claim I, characterized in that the material to be extracted dissolved in a light solvent is introduced into the first tank and a heavy solvent in the second tank.

2. Method according to claim I, characterized in that the solvent is vaporized under a partial vacuum.

3. Method according to claim I, characterized in that the vapors formed in the first tank are condensed by a reflux condenser.

4. Method according to sub-claims 2 and 3, characterized in that a partial vacuum is established through the reflux condenser.

5. Method according to claim I, characterized in that causes the stirring of the liquids and the divided solid matter contained in the first tank.

6. Device according to claim II, characterized in that it comprises means for heating the tanks and the duct.

7. Device according to claim II, characterized in that this duct comprises a filter.

8. Device according to sub-claim 7, characterized in that the filter consists of a tubing pierced with openings of small dimensions and surrounded by a very permeable sleeve.

9. Device according to sub-claim 7, characterized in that the filter terminates the conduit in the extraction tank.

10. Device according to claim II, characterized in that the extraction tank contains a drum pierced with openings of small dimensions, internally lined with a very permeable sleeve and subjected to a reciprocating rotary movement.

11. Device according to claim II, characterized in that the extraction tank contains a solvent dispersion member.

12. Device according to claim II and subclaim 6, characterized in that the extraction tank is provided with a reflux condenser and in that said condensers have a double cooling wall.

13. Device according to claim II and sub-claim 6, characterized in that the means for heating the tanks and the duct are adjustable electrical resistors.

14. Device according to claim II and sub-claims 6, 7 and 12, characterized in that the conduit, the condenser, the reflux condenser and the filter are removable.

15. Device according to claim II, characterized in that the conduit has a three-way valve.