| JP2009035908 | FRP DIE MATERIAL |
| JP08004198 | REINFORCED STRUCTURAL MEMBER AND CONNECTION MATERIAL USED WITH THE SAME |
| WO/2006/020062 | A FLEXIBLE, DEPLOYMENT RATE DAMPED HINGE |
MORO, Damiano (Via Conselvana, 16/C, Maserà di Padova, I-35020, IT)
| CLAIMS 1. A portable apparatus for rapid dynamic liquid-solid extraction, characterized in that it comprises an extraction chamber formed in a tank provided with an outlet; said tank being closed at an upward region by a removable lid; said extraction chamber being connected to a compression assembly by means of a manifold provided with a valve for discharging a liquid; said manifold being associated with said outlet; said extraction chamber, said compression assembly and said manifold are supported by a portable frame. 2. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 1 , characterized in that said extraction chamber comprises at least one diffuser inside said tank; said diffuser comprising a perforated partition arranged upstream of said outlet. 3. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 1 , characterized in that said extraction chamber comprises a one-way discharge valve associated with said outlet; said one-way discharge valve being connected to said manifold. 4. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 2, characterized in that said extraction chamber comprises a one-way intake valve which is associated with an inlet provided on said tank; said inlet being formed upstream of said diffuser; said one-way intake valve being connected to said manifold. 5. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 1 , characterized in that said compression assembly comprises a piston slidingly arranged in a cylinder which is connected to said manifold; said piston being actuated by a double-acting pneumatic actuator. 6. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 2, characterized in that it comprises a pressing assembly which is associated with said extraction chamber; said pressing assembly comprising a pressing member having a profile which is substantially complementary to a profile of a transverse cross-section of said tank; said pressing member being slidingly arranged in said tank upstream of said diffuser; said presser being actuated by a second pneumatic actuator. 7. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 6, characterized in that it comprises a pneumatic circuit connected to said double- acting pneumatic actuator and to said second pneumatic actuator; said pneumatic circuit being supplied by an external compressed air source to which it is connected by means of a pressure regulator-filter. 8. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 7, characterized in that said pneumatic circuit comprises a first electric valve, which actuates said double-acting pneumatic actuator and a second electric valve, which allows the introduction of air into said tank in order to facilitate its emptying; said second electric valve being connected to a pressure regulator. 9. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 7, characterized in that said pneumatic circuit comprises a manual actuation valve, which actuates said pneumatic actuator of said pressing assembly. 10. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 8, characterized in that it comprises a control device which is connected to said electric valves and is provided with a control keypad; said control device controls the opening and closing of said electric valves in order to semiautomatically manage the operation of said portable apparatus. 11. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 1 , characterized in that said lid comprises at least one gasket; said lid is removably locked by at least one first clamp. 12. The portable apparatus for rapid dynamic liquid-solid extraction according to claim 1 , characterized in that it comprises a bottom member which closes said tank in a lower region; said bottom member being provided with at least one gasket; said bottom member being removably locked by at least one second clamp. |
The present invention relates to a portable apparatus for rapid dynamic liquid- solid extraction.
As is known, liquid-solid extraction, or leaching, is an operation that allows to extract a solute contained in a solid matrix that is insoluble in the extraction liquid, by means of a liquid solvent with the capacity to solubilize the solution.
The simplest liquid-solid extraction process is steeping, i.e., a method according to which the solid matrix, placed in an adapted container, is covered by the extraction liquid and left in contact with it at ambient temperature for a sufficiently long time.
The time needed to complete the extraction by steeping ranges from a minimum of twenty-four hours to several days depending on the type of material subjected to extraction, while the volume of liquid used is proportional to the quantity of solid material to be extracted, because it must ensure complete covering.
This process is based essentially on Fick's law of diffusion, which sets the parameters of the extraction phenomenon and indicates that it is possible to increase the speed of the process by increasing the exposed surface of the solid and/or the temperature.
As an alternative to steeping, it is possible to use percolation, which allows to accelerate the extraction process by placing the solid material to be extracted in a glass or steel column and making the extraction liquid percolate thereon.
However, since the solid material, in order to be better extracted, must be comminuted and since large quantities of material are treated for each extraction cycle, the liquid is unable to percolate at atmospheric pressure but must be propelled by adapted pumps.
This last circumstance sets considerable limitations to the comminution of the solid material to be treated, because the pressure to be applied, in order to move the liquid, may become excessively high in the case of finely shredded material.
A more advanced system for performing liquid-solid extraction is constituted by the Soxhiet extractor, which is generally used in chemical laboratory work to prepare extracts that must be subjected to analysis. Its operation is based on the fact that the solid to be extracted comes into contact with pure solvent at each extraction cycle, because it is kept separate from the solid in a special glass apparatus, known indeed as Soxhlet apparatus from the name of its inventor, in which the solvent heated to its boiling point by immersion condenses continuously in a closed circuit.
Such technique allows a faster extraction than steeping, but it still takes a long time, because it is necessary to perform at least ten extraction cycles; the minimum extraction time for the completion of ten cycles is approximately eight hours.
Also, it should also be noted that use of such system requires a large amount of water for the operation of the condenser and a substantial amount of electric power to heat the bath required for the evaporation of the liquid.
Also, the extraction liquid is at boiling point for all the duration of the extraction process, therefore the extracted substances that are temperature-sensitive encounter a thermal degradation, because they are in the solvent at boiling point for a long time.
Another extraction system, manufactured by the American company Dionex and known commercially by the acronym ASE, which stands for Accelerated Solvent Extraction, introduces, as additional parameter to steeping, the variation of the temperature with consequent pressure variation.
According to the ASE system, the solid material to be extracted is placed in a reinforced steel cylinder and submerged in the solvent. The temperature is then raised beyond the boiling point of the solvent and, in order to prevent the liquid from passing into the gaseous state, the pressure has to be increased beyond 200 bars.
Despite being advantageous in many respects and substantially meeting the goal, known liquid-solid extractors have drawbacks.
It should be noted in particular that during steeping the compounds that are present in solid matrices are extracted by the contact that the extraction liquid can establish with those substances at atmospheric pressure and ambient temperature; accordingly, such technique has the drawback of requiring a relatively long time. In order to increase the extraction speed, it is possible to increase the exposed surface by pulverizing the material, with all the difficulties entailed by such operation. It is also possible to increase the temperature, in order to increase the diffusion of the extracted substances, with the risk however of destroying or deteriorating active principles and heat-sensitive substances.
Percolation accelerates the extraction process, because the extraction liquid is made to percolate several times on the solid, but the extraction is in any case regulated by Fick's law. Such method is used for processes that use large quantities of solid; the advantage of speed of extraction is contrasted by the poor efficiency of the process, the overall yield of which is about 60%, i.e., approximately 40% of the active principles are left in the solid and are consequently lost.
Regarding the Soxhlet extractor, it should be noted that it is a laboratory extraction method and is unlikely to be adopted at industrial level, because of the large amounts of energy and water to be used and of the danger of boiling organic liquids.
Soxhlet extraction is applied in the preparation of extracts that must be analyzed in a laboratory, such as the extraction of the fatty component of foods, the extraction of hydrocarbons or heavy metals from polluted soils, etc.
What has been said for the Soxhlet extractor also applies to the ASE system; it is in fact a device used exclusively to prepare extracts that must be subjected to analysis.
Bearing in mind that currently it is not yet possible to find large liquid-solid extractors based on the ASE operating principle, the main limitation of an ASE extractor resides in that it allows to extract only substances that are not degraded at high temperatures.
A further prior art extraction system is the extraction by means of supercritical fluids, particularly by means of carbon dioxide. Supercritical fluid extraction is prevalent in industrial systems because it is economically advantageous for producing products with a high added value. Supercritical fluid extraction is used, for example, for extracting nicotine from tobacco, caffeine from coffee and oils from seeds. Laboratory systems that base their operation on supercritical fluids are very expensive and very complicated to operate.
Also, the extraction with supercritical carbon dioxide is not a versatile extraction technique because it extracts predominantly compounds with low polarity, due to the fact that supercritical C0 2 assumes the characteristics of n-hexane, which is a highly apolar liquid.
The aim of the invention is to overcome the problems described above by providing a portable apparatus for rapid dynamic liquid-solid extraction that completes the extraction in a very short time, by means of a liquid solvent, of a solute contained in a solid matrix that is insoluble in the solvent.
Within the scope of this aim, a particular object of the invention is to provide a portable apparatus for rapid dynamic liquid-solid extraction that utilizes the generation of a difference in pressure between the inside and the outside of the solid matrix to provide the extraction process.
A further object of the invention is to provide a portable apparatus for rapid dynamic liquid-solid extraction that allows to extract substantially any compound that is not chemically bonded to the solid matrix, in a liquid in which it is not necessarily soluble.
A further object of the invention is to provide a portable apparatus for rapid dynamic liquid-solid extraction which allows to considerably reduce extraction time and does not chemically alter the extracted substances if they are thermolabile.
This aim, these objects and others that will become better apparent hereinafter are achieved by a portable apparatus for rapid dynamic liquid-solid extraction, characterized in that it comprises an extraction chamber formed in a tank provided with an outlet; said tank being closed in an upward region by a removable lid; said extraction chamber being connected to a compression assembly by means of a manifold provided with a valve for discharging a liquid; said manifold being associated with said outlet; said extraction chamber, said compression assembly and said manifold are supported by a portable frame.
Further characteristics and advantages will become better apparent from the detailed description of a portable apparatus for rapid dynamic liquid-solid extraction according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:
Figure 1 is a perspective view of a portable apparatus for rapid dynamic liquid- solid extraction according to the invention; Figure 2 is a front perspective view of a portable apparatus for rapid dynamic liquid-solid extraction according to the invention;
Figure 3 is a partially sectional front perspective view of a portable apparatus for rapid dynamic liquid-solid extraction according to the invention.
With reference to the cited figures, a portable apparatus for rapid dynamic liquid- solid extraction, according to the invention, generally designated by the reference numeral 1 , comprises an extraction chamber 10 connected to a compression assembly 20 by means of a manifold 30. Those components are supported by a portable frame 50.
The extraction chamber 10 contains a liquid solvent and a solid matrix containing a solute to be extracted is immersed in such liquid solvent.
The extraction chamber 10 is formed in a cylindrical tank 11 which is fastened to the portable frame 50.
The tank 11 is closed at the upper region by a lid 12 which is sealed by one or more silicone gaskets and is locked in a removable manner by a first clamp 13a.
The lower end of the tank 11 is closed by a bottom 19, which is locked in a removable manner by a second clamp 13b. The bottom 19 is sealed by one or more silicone gaskets.
The bottom 19 comprises an outlet 14 having a one-way discharge valve 15. An inlet 16 is provided substantially at the end of the tank 11 that is closed by the lid 12. The inlet 16 has a one-way intake valve 17.
A diffuser 18, inside the tank 11 , comprises a perforated partition arranged downstream of the inlet 16 and upstream of the outlet 14.
In this embodiment, the extraction chamber 10 has a pressing assembly 40 adapted to compress the contents of the tank 11 , at the end of the process cycle, so as to also recover the liquid that imbibes the solid matrix.
The pressing assembly 40 comprises a pressing member 41 which is actuated by a pneumatic actuator 42 that is fixed to the lid 12.
The pressing member 41 has a profile whose shape is substantially complementary to the shape of the profile of the transverse cross-section of the tank 11. The pressing member 41 is slidingly arranged within the tank 11 , upstream of the diffuser 18.
The extraction chamber 10 is cyclically pressurized and depressurized by the compression assembly 20, which is advantageously constituted by a piston 21 which is slidingly arranged within a cylinder 23 and is actuated by a double-acting pneumatic actuator 22.
The compression assembly 20 communicates with the extraction chamber 10 by means of a manifold 30, which is connected to the one-way intake valve 17, to the oneway discharge valve 15 and to the cylinder 23.
The manifold 30 is provided with a valve 31 for discharging the liquid contained in the tank 11.
According to a preferred embodiment, the main components of the portable apparatus for rapid dynamic liquid-solid extraction 1 , i.e. the extraction chamber 10, the compression assembly 20, the manifold 30, the pressing assembly 40 and the portable frame 50, are made of stainless steel.
The compression assembly 20 and the pressing assembly 40 are actuated by a pneumatic circuit 60 which is powered by an external compressed air generator to which it can be connected by means of a pressure regulator-filter 61.
The pressure regulator-filter 61 is connected to a first electric valve 62 and to a second electric valve 63. The first electric valve 62 actuates the pneumatic double-acting pneumatic actuator 22. The second electric valve 63 allows air inside the tank 11 in order to facilitate the emptying thereof at the end of the extraction cycle.
The pressure of the air introduced in the tank 11 is moderated by a pressure reduction unit 64 connected to the second electric valve 63.
A manual actuation valve 65 is also connected to the pneumatic circuit 60 and regulates the operation of the pneumatic actuator 42.
The operation of the portable apparatus for rapid dynamic liquid-solid extraction 1 is managed semiautomatically by a control device 70, which substantially actuates the opening and closing of the first electric valve 62 and of the second electric valve 63.
The control device 70, with the aid of a microprocessor logic unit, which is not shown in the figures, allows to customize the extraction cycles and to optimize them depending on the solid matrix, on the solvent and on the requirements of the operator.
A user interacts with the control device 70 by means of a control keypad 71 , while the electric power supply thereof is regulated by a master switch 72.
Substantially all the components of the portable apparatus for rapid dynamic liquid-solid extraction are supported by the portable frame 50, which is configured to be compact, easy to move and easy to place in different locations according to the requirements. Namely, the portable frame 50 comprises a substantially flat wall 52 mounted on a base plate 51.
The base plate 51 rests on a surface by means of feet 53, while the wall 52 acts as a support for the various components and allows the anchoring of a carrying handle 54.
The operation of the apparatus according to the invention is as follows.
A preparation step of the portable apparatus generally comprises connecting the apparatus to the electric power supply and connecting the pneumatic circuit 62 to an external compressed air source.
The supply air must be suitably dehydrated, de-dusted and de-oiled and preferably has a pressure between 5 and 10 bars.
When the preliminary connection operations are completed, the extraction chamber 10 is prepared by first introducing the solid matrix and then introducing the extraction liquid until the tank 11 is filled completely.
It has been found that it is particularly advantageous to beforehand introduce the solid matrix in a reusable filtering container, such as for example a bag. In such manner, the emptying and washing operations are facilitated and the extract is already filtered at the end of the extraction process.
After filling the tank 11 , the lid 12 is closed, fixing it with the first clamp 13a, and the extraction process begins.
The extraction process progresses by means of multiple cycles of compression and decompression of the extraction liquid inside the circuit.
Each extraction cycle alternates a dynamic step, wherein the material contained in the tank 11 is subjected to rapid pressure/depressure, and a static step, during which the extraction liquid penetrates the solid matrix and transfers the active principles into the solvent.
By means of the control device 70, it is possible to set the duration of the static step, the number of repetitions of the dynamic step and the number of total cycles.
Once the static step has been completed, the tank 11 is depressurized and the liquid outside the solid matrix rapidly reaches atmospheric pressure, while the liquid inside the solid matrix is, albeit for a short time, at the pressure reached previously in the static step (8-10 bars). The difference in pressure between the inside and the outside of the solid matrix causes a sudden displacement of liquid from the inside to the outside of the solid. Such sudden displacement mechanically conveys the compounds that are not chemically bonded to the solid matrix outward, i.e., into the extraction liquid.
It should be noted that the one-way discharge valve 15 and the one-way intake valve 17, combined with the suction and pressing action of the compression assembly 20, cause a remixing of the liquid inside the tank 11 , facilitating and further accelerating the extraction.
At the end of the extraction cycles, it is possible to drain the liquid by opening the discharge valve 31 and introducing air in the tank 11.
During or after discharge, it is possible to recover the liquid imbibed in the solid material by activating the pressing assembly 40, by acting on the actuation valve 65. The operation can be repeated in order to achieve a higher efficiency in recovering the liquid imbibed in the solid matrix.
After discharging the circuit is possible to open the lid 12 and remove the filtering container from the tank 11. The exhausted content of the filtering container may be disposed in compliance with applicable statutory provisions. The portable apparatus 1 may then be washed.
It is apparent, from what has been described above, that the substances contained in the solid are forced to exit by the difference in pressure that propels the substances towards the outside of the solid matrix at each extraction cycle composed of a dynamic step and a static step.
This allows to considerably shorten the extraction time, because the forced extraction makes the extraction process become active, and at the same time allows to prevent the chemical alteration of the extracted substances, if they are thermolabile, because the extraction can be performed at ambient temperature or at temperatures below ambient temperature.
It should also be noted that the extraction process is based essentially on a physical principle, so that any compound that is not chemically bonded to the solid matrix can be extracted in a heterogeneous phase, i.e., in a liquid in which it is not soluble.
This application claims the priority of Italian Utility Application No. VI2011 U000005, filed on January 26, 2011 , the subject matter of which is incorporated herein by reference.
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