Abstract: The invention concerns a method for making very fine particles containing at least an active principle inserted in a host molecule and a device for implementing said method. The method is characterized in that it consists in forming a solution of the active principle in a first liquid solvent and of a product formed by the host molecules in a second liquid solvent, then in contacting the resulting solutions with a supercritical pressure fluid, so as to precipitate the host molecules which are dissolved therein.

Abstract: The invention concerns a method for capturing very fine particles present in a fluid flux in liquid, gaseous or supercritical state and a device therefor. The method is characterized in that it comprises steps which consist in: causing said flux to pass through a filtering element (13); stopping the emission of said flux; countercurrent clearing of the filtering material (31) with a carbon dioxide flow under pressure, so as to drive the particles deposited on the filtering material (31); countercurrent expanding of the flux, so as to trap the particles within a solid carbon dioxide snow-type mixture formed during its expansion.

Abstract: The invention concerns a method and an installation for setting in adsorbed state, on a porous support, compounds contained in a product comprising a first step which consists in extracting the compounds by contacting the product with at least a solvent at supercritical pressure to obtain a mixture of extracts and solvent. The method is characterized in that it comprises a second step which consists in eliminating the water contained in the mixture of extracts and solvent, adjusting the temperature and pressure conditions so as to obtain, a first phase consisting of solvent in gaseous state and a second phase consisting of a mixture of liquids formed of solvent and extracts of the products; causing said two phases to trickle through a porous support adapted to adsorb the extracts; vaporizing the solvent contained in the second phase.

Abstract: The invention relates to a device for fractionating mixtures comprising separation elements which are series mounted and mounted in a closed loop. Said device is characterized in that the solvent used is a supercritical pressurized fluid, each of the separation elements is made of a membrane separation, it comprises means for injecting the solvent at a pressure which is greater than the critical pressure thereof and for maintaining the pressure in said loop at a value which is above critical pressure, and it further comprises means for injecting the diluent and for maintaining the pressure thereof at a value which is similar to the value of the pressure of the solvent (S) in each of the areas (I, II, III, IV).

Abstract: A chromatographic simulated moving bed separation process is most generally characterized by a recycling pump which successively adopts the flow rate characteristics of 4 or 5 zones of the process. The invention describes the method by which a conventional simulated moving bed separator process can be adapted to a simulated moving bed process in which the recycling pump is operated at an optimal constant flow rate. In order to achieve this, throughout the cycle all the introduction and extraction circuits are shifted using independent means, such that the eluted volume at the outlet to each zone remains substantially constant, zone by zone, between two successive shifts throughout the cycle.

Abstract: A process for obtaining an aerogel from a polymeric material that is in the form a sol-gel in an organic solvent, by exchanging the organic solvent for a fluid having a critical temperature below a temperature of polymer decomposition, and supercritically drying the fluid/sol-gel. The process is carried out in a semi-continuous mode that includes the steps of contacting the initial sol-gel with a stream of the fluid at different pressures and temperatures through n+1 pressure vessels A.sub.0 to A.sub.n that each have an inlet for fluid VI.sub.i and an outlet for effluent VO.sub.i wherein the n+1 pressure vessels are operated dependently on each other through a joint fluid supply system and a joint effluent treatment system so that the respective product in each of the pressure vessels A.sub.0 to A.sub.n is submitted to the fluid in successive steps with pressure and temperature following a curve that never cuts the vaporization curve in the pressure-temperature diagram of FIG. 1.

Abstract: A chromatographic simulated moving bed separation process is most generally characterized by a recycling pump which successively adopts the flow rate characteristics of 4 or 5 zones of the process. The invention describes the method by which a conventional simulated moving bed separator process can be adapted to a simulated moving bed process in which the recycling pump is operated at an optimal constant flow rate. In order to achieve this, throughout the cycle all the introduction and extraction circuits are shifted using independent means, such that the eluted volume at the outlet to each zone remains substantially constant, zone by zone, between two successive shifts throughout the cycle.

Abstract: In a simulated mobile bed separation process, perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) or compressor for a liquid, supercritical or gaseous mixture in a closed circuit of column sections. The volume of the section immediately upstream of the dead volume is reduced by an appropriate value when said dead volume is located downstream of this section and upstream of the extraction streams of said section, or the volume of the section immediately downstream of the dead volume is reduced by an appropriate value when the dead volume is located downstream of the injection streams into said section and upstream of this section.The invention is applicable to the separation of isomers of aromatic hydrocarbons containing 8 carbon atoms.

Abstract: Perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) for a liquid, supercritical or gaseous mixture in a closed circuit of column sections, or due to a degradation in their separating power each time an injection or extraction stream passes from a position anterior to a position posterior to each of the dead volumes in the circuit or each section whose separation power has been degraded. Firstly, the connection period for said stream to the circuit is increased by an appropriate value, and then when the stream passes from the posterior position to the dead volume, or connection to the degraded section, to the following position, the connection period is reduced so that the period regains the value which would have been applied if each of the dead volumes had been ignored or the degradation in the separation powers had been ignored.

Abstract: An apparatus and process for fractionation of component mixtures by chromatography or adsorption on a simulated mobile bed comprising three, four or five zones is described. A compressed gas is injected as eluent (IE, IR) using a compressor or pump, the pressure being lower than the critical pressure of the gas. At any point in at least one zone and preferably at any point in at least two zones from the eluent injection point (IR), the gas has a compressibility coefficient substantially different to 1. A supercritical fluid or a subcritical liquid may equally be injected as the eluent. The pressure between each zone may be altered.

Abstract: A membrane assembly for fluid separations consisting of a compact stack of alternating layers of membrane with layers of fluid conducting materials. The assembly consists of a simplified and improved plate and frame apparatus. The stacked assembly may be placed into a pressure containment device consisting of standard pipe with standard methods of closure. Internal fluid conducting passages are formed from cutouts in the stacked layers thereby greatly simplifying the manufacture and assembly of large diameter fluid separation devices using membranes to effect the fluid separations. The fluid pathways are such that the membrane assembly is particularly efficient in separation.

Abstract: A decanting centrifuge for processing liquid material in cylindrical open-topped sample tubes supported on the rotor and movable from a first position with the open ends directed towards the rotor axis and a second position for decanting supernatant from the sample tubes under the influence of the centrifugal force. In the second position the sample tubes are horizontal or include a relatively small angle with the horizontal, and the radially outermost generatrix of the inner surface of the sample tubes is tangent to an imaginary circular cylindrical surface concentric with the rotor, the tangent point being spaced by a predetermined distance from the closed bottom end of the sample tubes, so that a predetermined volume is retained between the tangent point and the bottom end.

Abstract: An apparatus for continuously transmitting electrical energy or a fluid stream between a fixed terminal and a continuously rotating terminal through a flexible continuous transmission element, such as an electric cable or a tube, comprises three rotors having a common axis of rotation, namely an outer rotor, an intermediate rotor and an inner rotor. The outer and intermediate rotors are rotated at approximately equal speeds in opposite directions, and the inner rotor is driven by the torsionally rigid, filiform transmission element in the same direction as the intermediate rotor at a speed equal to twice the sum of the speeds of the outer and intermediate rotors. The transmission element extends between the fixed and rotating terminals in an outer bight supported by the outer rotor and an inner bight supported by the intermediate rotor and is rotatable about its own curvilinear axis relative to the rotors.

Abstract: A centrifuge apparatus, primarily for use in the continuous or semi-continuous separation of blood, has a disposable separation unit which is orbited on a centrifuge rotor. The separation unit has a sealed jacket which is held against rotation during the orbiting and communicates with a stationary and nonrotatable liquid inlet and outlet connector on the rotor axis. A separation vessel rotatably mounted in the jacket communicates with liquid inlet and outlet passages in the jacket and is rotationally unbalanced to orient itself relative to the rotor during the orbiting of the jacket.