Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
  • F26B11/02—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles
  • F26B11/04—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis
  • F26B11/049—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis with provisions for working under increased or reduced pressure, with or without heating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
  • F26B11/02—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles
  • F26B11/026—Arrangements for charging or discharging the materials to be dried, e.g. discharging by reversing drum rotation, using spiral-type inserts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
  • F26B11/02—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles
  • F26B11/04—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis
  • F26B11/0445—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis having conductive heating arrangements, e.g. heated drum wall

Definitions

• the invention relates to the field of devices ensuring product treatment by lyophilization.
• the invention relates more particularly to devices carrying out bulk lyophilization.
• the invention also relates to a bulk lyophilization process.
• the invention finds a particularly advantageous application in the fields of pharmaceutical preparation and food preparation and, more generally, for all high value-added industries which require a freeze-drying preservation process.
• the invention can be implemented in the field of biotechnology for the production of inoculum for the fermentation of biomass, in the food field for lyophilization of fruits, vegetables, beverages and food preparations, in the field of health for lyophilization of proteins, peptides, enzymes, bacteria, viruses, living cells, sensitive formulation based on antibodies or sensitive molecules, plasma fraction or formulation of sensitive polymers .
• Lyophilization is a low-temperature dehydration process that consists of removing most of the water contained in a product by sublimation. Lyophilization provides high quality end products without degrading the structure and retaining much of the activity of microorganisms or cells. Freeze-dried products have a long-term storage capacity due to the lowering of the water activity of the product.
• lyophilization is, however, limited by its cost and remains well below the use of drying.
• the low productivity in lyophilization is due to the discontinuous mode of operation under vacuum and at a very low temperature which results in significant processing times of between ten hours and several days. Under these extreme conditions, heat transfer has a very low efficiency.
• the drying is conventionally carried out at atmospheric pressure with very low temperatures, generally between 50 and 100 ° C., and heat transfer with a better yield.
• the investment and operating costs of freeze-drying devices are high.
• the energy consumption of a freeze-drying device is typically of the order of 2500 to 6000 kWh per ton of water to be eliminated.
• Lyophilization requires the use of a device which consists of a freezing chamber connected to cooling means, an evaporation chamber connected to heating means and a condensation chamber connected to the chamber evaporation.
• the condensation chamber is configured to collect water vapor from the evaporation chamber on an ice trap.
• the evaporation chamber also performs the freezing of the products prior to evaporation.
• the freezing is conventionally carried out in an independent device, so that the lyophilization device itself only includes an evaporation chamber and a condensation chamber. Cooling means are arranged in the condensation chamber to freeze the water vapor from the evaporation chamber.
• the water in the form of steam is then transformed into ice in the condensation chamber and the ice is stored in the condensation chamber on the ice trap.
• freezing and sublimation can be carried out within the same enclosure.
• the freezing chamber and the evaporation chamber consist of a single chamber connected to the cooling means and the heating means.
• the chambers are also evacuated by a vacuum pump so as to pass under the triple point of the water and allow the passage of water from the solid phase to the gas phase.
• the lyophilization process has a first step of freezing the products in the freezing and evaporation chamber to allow their drying at low temperature. Fast freezing is desired so as to form small ice crystals. Too slow freezing has the effect of promoting the formation of large crystals likely to damage the structure of the product by tearing the walls of its cells, for example for yeasts, viruses and animal or plant cells.
• a second step is to create a vacuum in the evaporation chamber, the low pressure, usually well below 6.1 hPa, allowing the water in the form of ice to turn into vapor without thawing the products.
• the products receive a heat input to provide the energy needed for the latent heat of sublimation of the ice to steam.
• the vapor enters the condensation chamber while the condensation chamber is conditioned to transform the water vapor into ice by the use of an ice trap maintained at a very low temperature, generally -60 ° C.
• freeze-drying process makes it possible to extract up to 95% of the water contained in the products. Freeze-drying can reduce the moisture content of the product to an extremely low level, between 1% and 10% of the product's density, and prevent bacteria and molds from proliferating and the enzymes from triggering chemical reactions to deteriorate the product. It follows that freeze-dried products are very long-lasting. In an airtight package, protected from moisture, light and oxygen, freeze-dried products can be stored at room temperature for many years. In addition, the high quality of sterilized products also requires sterilization of the sterilization chain.
• the lyophilization time depends on the particle size of the products to be freeze-dried and the surface of the products coming into contact with the heat source.
• a conventional solution consists in distributing the products to be freeze-dried in small flasks.
• the heat source is configured to heat the base of the vials to transmit heat to all the products stored in the vials by conduction and radiation. After lyophilization, the product appears as a porous cake conforming to the shape of the bottle.
• the average lyophilization time is thus between two and three days because of the time of migration of heat by conduction and by radiation in the flasks.
• the distribution of the products to be freeze-dried in a large number of flasks requires a large size of the evaporation chamber. It follows that the power of the heating means, cooling means and vacuum means must be increased accordingly.
• Freeze-drying in bulk makes it possible to obtain an average freeze-drying time of between five and fifty hours.
• the reduction of the lyophilization time makes it possible to reduce the consumption, the production time and therefore the cost of production.
• the limitation of the lyophilization time reduces the exposure of the product to heat. It is thus possible to improve the quality of the lyophilized product.
• Documents WO 82/02246 and EP 1 236 962 describe lyophilization chambers whose evaporation chamber is rotatable. However, these devices require a complete stop of the evaporation chamber to introduce and extract the products. Indeed, the evaporation chamber in these documents is evacuated during lyophilization and the introduction and extraction of the products requires the return to atmospheric pressure and the opening of a sealed wall. Thus, the methods of introduction and extraction of products are particularly long and complex.
• an operator connects a sterile inlet to the evaporation chamber through the sterile chamber so as to reach the vessel.
• the products to be freeze-dried are then placed in the tank through the sterile inlet and the sterile enclosure.
• the operator then disconnects the input while making sure to keep the sterility in the enclosure.
• Lyophilization is then performed while the motor rotates the tank so as to stir the products to prevent their agglomeration.
• the evaporation and condensation chambers are in communication but do not rotate.
• the operator connects a sterile outlet to the evaporation chamber through the sterile enclosure so as to extract the lyophilized products from the tank.
• freeze-drying device Due to the pressures applied and the difference in temperature, the seal disposed around the axis is rapidly degraded, which can lead to leakage or sterility.
• this freeze-drying device also requires very precise handling of the operator in order to guarantee the sterility of the products.
• the freeze-drying devices require steps of handling an operator between two lyophilizations. It follows that lyophilization is a treatment that is very little automated thus increasing the production time and therefore the cost of lyophilized products. The problem of the invention therefore consists in developing a freeze-drying device for bulk products that meets the disadvantages of the devices of the prior art.
• the present invention aims to solve this problem by mounting the inlet and the outlet of the evaporation chamber on flexible connectors and stirring the evaporation and condensation chambers in a back and forth motion. It follows that the inlet and outlet are permanently connected to the evaporation chamber and it is no longer necessary to mount the two chambers in a sterile enclosure. In addition, the movement back and forth allows the use of heat transfer fluids circulating in double envelopes around the evaporation and condensation chambers by connecting the inputs and outputs of these fluids by flexible connectors. Thus, the heating and cooling can be carried out by conduction at the support surface of the products in the evaporation chamber and by radiation on the rest of the surface of the evaporation chamber.
• the heat transfers can only be carried out by radiation around the evaporation and condensation chambers.
• the conduction heat transfer allowed by the invention improves the accuracy of heat transfer and reduces consumption.
• the invention relates to a freeze-drying device comprising:
• an evaporation chamber comprising means for heating the evaporation chamber configured to sublimate the water contained in the frozen products intended to be arranged in the evaporation chamber, a condensation chamber communicating with the chamber; evaporation, and comprising means for cooling the condensation chamber configured to transform the steam from the evaporation chamber to ice,
• the device further comprises:
• This device makes it possible to perform a batch lyophilization.
• the invention relates to a lyophilization process implemented by the device previously described, comprising the steps of:
• an operator supervises these manufacturing steps by means of temperature sensors arranged in the evaporation chamber and in the condensation chamber.
• lyophilization can be carried out continuously by compartments in the evaporation chamber.
• a third movement of rotation of the axis of large amplitude makes it possible to transfer the products to be lyophilized between the compartments of the evaporation chamber so as to create a freeze-drying path inside the evaporation chamber.
• the motor drives the axis on itself according to at least three complementary movements:
• the invention makes it possible to carry out a continuous freeze-drying, that is to say that products can be introduced regularly over time without requiring the complete stoppage of the lyophilization process.
• products can be introduced through the inlet into the first compartment of the evaporation chamber while other products disposed in the evaporation chamber and other compartments are still being lyophilized.
• lyophilized products can be removed from the evaporation chamber while other products are still being lyophilized.
• the inlet comprises a loading chamber partitioned by two locks and the outlet comprises an unloading chamber partitioned by two locks.
• the opening of the sluice separating the inlet of the evaporation chamber and the opening of the sluice separating the outlet from the evaporation chamber are synchronized with the third movement of said engine. This embodiment makes it possible not to interrupt the lyophilization cycle to introduce or extract products into the evaporation chamber.
• the device comprises two condensation chambers connected to the evaporation chamber by two separate locks, the first condensation chamber being connected to the evaporation chamber by opening the first airlock and closing the second chamber so using the first condensation chamber to trap the steam from the evaporation chamber, the second condensation chamber being regenerated when using the first condensation chamber and vice versa.
• This embodiment makes it possible to empty the trapped ice in one or the other of the condensation chambers without interrupting the continuous lyophilization process.
• the device comprises two vacuum pumps, a first vacuum pump connected to the first condensation chamber and a second vacuum pump connected to the second condensation chamber.
• This embodiment makes it possible to guarantee the evacuation of the condensation chambers when they are connected to the evaporation chamber and the depression of these chambers when they are in a regeneration phase.
• the evaporation chamber is inclined between the inlet and the outlet. This embodiment makes it possible to direct the products arranged in one compartment towards the next compartment in the direction of the exit.
• the axis can be inclined only during the large amplitude movement for the transfer of the product between two compartments.
• the partitions of the evaporation chamber have two distinct shapes mounted alternately in the evaporation chamber, the two forms having axially offset notches and intended for the passage of the product to be lyophilized between two compartments.
• the axial displacement of two consecutive partitions makes it possible to limit the risk of displacement of the product between several compartments during the movement of large amplitude aimed at transferring the product between two compartments.
• the motor is configured to drive the axis according to a fourth complementary movement with the three movements, the fourth movement driving the axis in rotation on itself in a direction opposite to the direction of the third movement with an angle rotation between 90 ° and 180 ° so as to move the products between two consecutive compartments of the evaporation chamber. This embodiment also makes it possible to improve the transfer of the product between two consecutive compartments.
• the invention also relates to a lyophilization process implemented by the device previously described, the method comprising the steps of:
• an operator supervises these manufacturing steps by means of temperature sensors arranged in the evaporation chamber and in the condensation chamber.
• the device used is suitable for continuous or discontinuous lyophilization, it may furthermore have the following characteristics.
• the evaporation chamber is disposed laterally with respect to the condensation chamber or chambers.
• a vapor sensor may be placed between the evaporation chamber and the condensation chamber, for example by means of a propeller driven by the vapor flow between the evaporation chamber and the condensation chamber during sublimation.
• the evaporation and condensation chambers are in the form of a generally cylindrical tank.
• the evaporation chamber presents a
• the device also comprises means for cooling the evaporation chamber.
• This embodiment makes it possible to use the evaporation chamber for freezing the products with the sublimation step.
• the products can be introduced into the evaporation chamber at room temperature and a first step is to freeze the products directly in the evaporation chamber before performing the sublimation.
• the movement back and forth of the evaporation chamber can be implemented during freezing.
• said chamber comprises an outer double wall, the heating means being configured to circulate a heat transfer fluid in a space formed between the two walls of the evaporation chamber.
• the cooling means of the condensation chamber and the heating means of the evaporation chamber are connected to their respective chambers by flexible connectors. This embodiment makes it possible to deport the energy production devices outside the mobile structure formed by the two chambers. Therefore, heating and cooling can be performed both by conduction at the wall level of the chamber with which the surface of the products is in contact and by radiation. This improves the accuracy of heat transfer and reduces consumption.
• the flexible connectors have several turns of stainless steel. This embodiment avoids the hardening of the metal forming the flexible connectors.
• the connectors may be made of a plastic material or a treated material to avoid hardening.
• the evaporation chamber comprises baffles arranged inside the evaporation chamber so as to promote the mixing of the products during the movements of the evaporation chamber.
• the baffles thus provide a mixture of the products during lyophilization.
• the device also comprises a first temperature sensor and a pressure sensor disposed in the evaporation chamber and a second temperature sensor disposed in the condensation chamber.
• This embodiment makes it possible to supervise the temperatures and the pressure in order to estimate the progress of the lyophilization process.
• Figure 1 is a schematic structural representation of a lyophilization device according to a first embodiment of the invention
• Figures 2a to 2d are sectional views of the position of a partition with respect to the evaporation chamber in four distinct positions of the freeze-drying device of Figure 1;
• Figure 3 is a schematic structural representation of a freeze-drying device according to a second embodiment of the invention.
• Figures 4a to 4d are sectional views of the position of a partition with respect to the evaporation chamber in four distinct positions of the lyophilization device of Figure 3;
• Figure 5 is a schematic structural representation of a lyophilization device according to a third embodiment of the invention.
• FIGS. 6a to 6e are sectional views of the position of two consecutive partitions with respect to the evaporation chamber in five distinct positions of the freeze-drying device of FIG. 5.
• FIG. 1 illustrates a freeze-drying device comprising an evaporation chamber 5 and a condensation chamber 10.
• An inlet 1 in the form of a hopper is connected to the evaporation chamber 5 via a flexible connector .
• the hopper is further equipped with a first lock 2 so as to introduce products to lyophilize when the lock 2 is open.
• An outlet 8 in the form of a hopper is also connected to the evaporation chamber 5 via a flexible connector.
• the hopper is further equipped with a second lock 9 so as to extract the freeze-dried products when the lock 9 is open.
• Locks 2 and 9 also ensure the tightness and sterility of rooms 5, 10. For example, locks 2, 9 of the brand "Agilent Technologies" or "Gericke" can be used.
• the invention can be implemented with a single input / output performing the two functions of introduction and extraction of products.
• the evaporation chamber 5 and the condensation chamber 10 are arranged in the extension of one another and independent of each other, that is to say that the two chambers form two spaces offset axially .
• the condensation chamber 10 may be arranged around the evaporation chamber 5, the two chambers are in this case concentric.
• the evaporation chamber 5 has a double outer wall in which a coolant circulates to heat the evaporation chamber 5.
• the inner surface of the evaporation chamber 5 is polished mirror so as to promote the sliding of load and minimize the bank angle.
• the coolant is heated by an external device connected to the double wall by a fluid inlet 15 and a fluid outlet 16.
• a vapor inlet 31 is also connected to the evaporation chamber 5 in order to sterilize the evaporation chamber 5.
• the coolant can be heated by a heat exchanger coupled to an external heat source.
• the products can be introduced in a frozen form through the inlet 1.
• the products can be frozen directly in the evaporation chamber 5.
• the products are introduced at ambient temperature and the heat transfer fluid flowing in the outer double wall is refrigerated at a very low temperature, for example of the order of -60 ° C, so as to lead to the freezing of the products before the evaporation step. Freezing can also be performed in the inlet 1.
• the freezing can be obtained directly in pellets by means of a droplet falling in a stream of nitrogen.
• the condensation chamber 10 is connected to the evaporation chamber 5 via an airlock 4.
• the airlock 4 is configured to pass steam between the evaporation chamber 5 and the condensation chamber 10.
• the airlock 4 may include a grid or a filter passing the vapor and retaining the particles of the product may be driven by water vapor.
• the filter is made of Gore-Tex®, registered trademark.
• the condensation chamber 10 comprises an ice trap 11 in the form of a coiled tube in which circulates a coolant, for example liquid nitrogen.
• the coolant is produced by an external device and is conducted in the pipe through an inlet 17 to an outlet 18.
• the heat transfer fluid can be cooled by a heat exchanger coupled to an external cold source.
• the cooling means 17, 18 are implemented when the lock 4 is open and the steam enters the condensation chamber.
• the vapor then freezes on the tube of the ice trap 11.
• the number of turns and the section of the tube forming the ice trap 11 are determined as a function of the amount of vapor to be recovered.
• a steam inlet 32 is also connected to the condensation chamber 10 to sterilize the condensation and evaporation chambers 10 prior to starting the actual lyophilization process. To do this, in a step prior to lyophilization, the lock 4 is opened and steam is introduced into the two chambers 5, 10.
• the steam injected by the steam injection nozzle 32 causes the melting of the ice present on the ice trap 11.
• a purge 33 thus extracts the injected vapor to evaporate the ice contained in the condensation chamber. 10 as well as the steam generated for sterilization.
• the condensation chamber 10 is also connected to a vacuum pump 6 via a pipe provided with a valve 7.
• This vacuum pump 6 is configured to evacuate the condensation chamber 10 and the vacuum chamber. evaporation 5 when the lock 4 is open.
• the valve 7 is kept open and the vacuum is preserved by the condensation of the steam on the ice trap 11.
• the inlet 1 and the outlet 8 of the inlet and outlet hoppers are connected to the evaporation chamber 5 by sterile flexible sleeves.
• the heating and cooling means of the two chambers 5, 10 and the vacuum pump 6 are also connected to the respective chambers by flexible connectors.
• the flexible connectors are made of stainless steel to meet sterility requirements.
• the flexible connectors advantageously have turns so as to limit the work hardening of the stainless steel.
• the flexible connectors have the function of connecting a fixed and external element, in this case the feed hoppers and discharges to the chambers 5, 10 so as to guarantee a connection of these elements with the chambers 5, 10 when these chambers are driven by rotation on itself by the motor 12.
• the bending capacity of these connectors thus makes it possible to absorb the displacements of the chambers 5, 10 with respect to the external elements.
• the length of the connectors is also chosen to guarantee the maintenance of the connection during the rotation of the chambers 5, 10.
• the flexible connectors of the brand "Stâubli ® " can be used.
• the two chambers 5, 10 are mounted integral on an axis 30.
• the two chambers are cylindrical and the axis 30 passes through the center of the two planar faces of the cylinders so as to distribute the mass of the chambers 5, 10 uniformly around of the axis 30.
• the axis 30 is connected and made integral with the end of the condensation chamber 10, opposite the end connected to the evaporation chamber 5.
• the axis 30 may be connected and secured to the evaporation chamber 5.
• the axis 30 can be maintained, free in rotation, by supports.
• the axis 30 is rotated by a motor 12.
• FIG. 2 illustrates the positions of the axis 30 during this movement back and forth.
• a first position illustrated in Figure 2a
• the axis 30 is not rotated by the motor 12.
• a first movement of the motor 12, shown in Figure 2b causes the axis 30 on itself and consequently the evaporation and condensation chambers in a first direction of rotation with an angular displacement al of less than 180 °.
• a second movement of the motor 12, illustrated in Figure 2c, causes the axis 30 on itself and therefore the evaporation chambers and condensation in a second direction of rotation, opposite the first direction of rotation, with a displacement angular a2 substantially equal to the angular displacement of the first movement.
• the movement back and forth corresponds to a sway of the axis 30, that is to say a rotation of the axis 30 on itself in one direction and then in the other.
• the axis 30 therefore does not perform a complete rotation thus limiting the risk of winding of the flexible connectors connecting the external devices to the chambers 5, 10.
• the flexible connectors are configured to deform and absorb the displacements of the chambers 5, 10 during rotations so as to maintain a tight and sterile connection.
• the evaporation chamber 5 also comprises baffles arranged inside the evaporation chamber 5.
• the baffles extend radially inwardly of the evaporation chamber 5 and make it possible to improve the mixing of the products during lyophilization.
• coulters of the brand "Palamatic ®" can be used.
• the axis 30 can be mounted horizontally relative to the cylindrical body of the chambers 5, 10.
• the device advantageously comprises means for pivoting the axis in the vertical plane for guiding the products arranged in the chamber. evaporation 5 to the outlet 8 when the lyophilization time is reached.
• the axis 30 may be biased, i.e. inclined in the vertical plane so as to guide the products to the outlet 8 throughout the lyophilization process.
• the output 8 is lower than the input 1 so as to use gravity to move the lyophilized products to the outlet 8.
• the chambers 5, 10 are preferably instrumented by temperature sensors 20, 24 and pressure sensors 21.
• Two sensors 20, 21 are arranged in the evaporation chamber 5 to control the temperature and the pressure in the evaporation chamber 5.
• a third sensor 24 is disposed in the condensation chamber 10 to control the temperature of the condensation chamber 10. It follows that an operator can follow the lyophilization process by means of the sensors 20, 21, 24 and estimate the amount of water removed from the products over time. It is thus possible to determine the precise moment for which a desired concentration of water is reached to stop lyophilization.
• an operator opens the lock 2 while the lock 4 the valve 7 and the lock 9 are closed. Products to be lyophilized are thus introduced into the evaporation chamber 5, for example previously frozen products. The lock 2 is then closed and the valve of the lock 4 is opened to put in communication the two chambers 5, 10.
• Vacuuming is then performed by opening the valve 7 and actuating the vacuum pump 6.
• the vacuum is essentially maintained by the condensation of the steam on the trap 11.
• the next step is to perform the sublimation of the water contained in the frozen products.
• the frozen products are heated by the operation of the heating means 15, 16 of the evaporation chamber 5 and actuation of the cooling means 17, 18 of the condensation chamber 10.
• the temperature of the products in the evaporation chamber 5 is moved from -30 ° C to -25 ° C under a vacuum of 6.1 hPa.
• the water of the frozen products is then sublimed and enters the condensation chamber 10 in the form of vapor where it is frozen and trapped in the condensation chamber 10 by the ice trap 11, the temperature of which is preferably between 50 ° C and -60 ° C.
• the gate or the membrane, preferably made of Gore-Tex ® present at the airlock 4 can prevent the release of product particles if the evaporation rate is important.
• the motor 12 drives the axis 30 in rotation on itself according to the two movements described above. These movements are alternately repeated for the duration of the sublimation.
• the motor may be a brushless electric motor (also called “brushless motor” in the English literature).
• the motor is an electric motor having a plurality of operating positions for which the magnetic field of the stator corresponds by an angular position of the rotor.
• the invention proposes to use the motor to perform a movement "back and forth".
• an electric motor that has four pairs of poles is conventionally rotated by successively feeding the consecutive pairs of poles: the first pole pair, the second pole pair, the third pole pair, the fourth pole pair, the first pair of poles ...
• the "back and forth" movement can be generated by feeding the first pair of poles, then the second pair of poles, then the first pair of poles, then the fourth pair of poles, then the first pair of pole, then the second pair of pole ...
• the evaporation and condensation chambers 10 can be mounted on wheels that are movable in the direction of rotation and configured to support the weight of the chambers.
• the airlock valve 4 When the lyophilization time is reached to obtain the desired water concentration, the airlock valve 4 is closed and the heating means 15, 16 and cooling 17, 18 are stopped.
• the lock 9 is opened and the freeze-dried products are extracted from the evaporation chamber 5 by the outlet 8.
• steam is introduced. in the condensation chamber 10 by the steam injection nozzles 31, 32 so as to cause a melting of the ice and a sterilization of the two chambers 5, 10.
• the vapor thus contained in the two chambers 5, 10 is extracted by the purge 33 or the outlet 8 when the product is removed from the condensation chamber 10.
• the lock 9 is closed, the two chambers 5, 10 are cooled by means of the connections 15-18 and a new lyophilization can to be carried out.
• FIG. 3 illustrates a second embodiment in which the evaporation chamber 5 comprises partitions 40 extending over only a portion of the height of the evaporation chamber 5 forming compartments between these partitions 40.
• the partitions 40 extend radially with respect to the evaporation chamber 5.
• the top of each partition 40 is provided with a notch 39 intended to allow the passage of products between two consecutive compartments.
• FIGS. 4 illustrate an exemplary embodiment of these partitions by the presence of a notch on the upper part of the partition 40.
• the device further comprises an inlet 1 connected to the evaporation chamber 5 via a loading chamber 41 so as to introduce products to be freeze-dried.
• the loading chamber 41 is partitioned by two locks 2a, 2b. Products are introduced into the loading chamber 41 from the inlet 1 when the first lock 2a is open. The first lock 2a is then closed and the second lock 2b is opened so as to introduce the products into the evaporation chamber 5.
• the outlet 8 is also connected to the evaporation chamber 5 via a chamber of unloading 42 also partitioned between two locks 9a, 9b.
• the motor 12 induces at least three rotational movements of the axis 30 on itself whose two movements are limited in amplitude so as to create a movement back and forth.
• a first movement of the motor 12, illustrated in Figure 4b causes the axis 30 on itself in a first direction of rotation with an angular displacement al between 5 ° and 90 °.
• This low amplitude rotation does not allow the products arranged in the compartment to migrate to the adjacent compartments because the height of the partition 40 is sufficient to contain the products.
• a second movement of the motor 12, illustrated in Figure 4c causes the axis 30 on itself in a second direction of rotation, opposite to the first direction of rotation, with an angular displacement a2 substantially equal to the angular displacement of the first movement.
• This low amplitude rotation does not allow the products arranged in the compartment to migrate to the adjacent compartments because the height of the partition 40 is sufficient to contain the products.
• the movement back and forth corresponds to a sway of the axis 30, that is to say a rotation of the axis 30 on itself in one direction and then in the other.
• a third movement of the motor 12, illustrated in Figure 4d, causes the axis 30 on itself with a rotation angle a3 of between 90 ° and 180 °.
• This movement of large amplitude aims to allow the movement of products between two consecutive compartments because the notch 39 of the partition 40 is arranged downwards.
• the axis 30 may be arranged horizontally relative to the cylindrical body of the chambers 5, 10.
• the device advantageously comprises means for pivoting the axis in the vertical plane in order to guide the products arranged in the chamber. of evaporation 5 between two consecutive compartments during the third movement.
• the axis 30 can be mounted with a bias, that is to say inclined in the vertical plane, so as to guide the products against the partition 40 during the movement back and forth and between two consecutive compartments when movement of great amplitude.
• the partitions 40 are made of metal so as to conduct heat to the heart of the evaporation chamber 5.
• the chambers 5, 10 are preferentially instrumented with temperature sensors 20, 24 and pressure sensors 21.
• an operator or an automaton opens the lock 2a and the compartment between the locks 2a and 2b is evacuated.
• the lock 2b is open and products to be lyophilized are thus introduced into the first compartment of the evaporation chamber 5, for example previously frozen products.
• the lock 2b is then closed and the lock 2a is opened once the vacuum has been established in the lock, so as to introduce new products into the loading chamber 41.
• the evacuation is initially performed by opening the valve 7 and actuation of the vacuum pump 6.
• the valve 7 remains open and the vacuum pump 6 continues to operate but the vacuum is essentially ensured by the condensation of the steam on the trap 11.
• the step Next is to sublimate the water of the frozen products.
• the frozen products are heated by the operation of the heating means 15, 16 of the evaporation chamber 5 and actuation of the cooling means 17, 18 of the condensation chamber 10.
• the temperature of the products in the evaporation chamber 5 is shifted from -30 ° C to -25 ° C under a vacuum of 6.1 hPa.
• the water of the frozen products is then sublimed and enters the condensation chamber 10 in the form of vapor where it is frozen and trapped in the condensation chamber 10 by the ice trap 11, the temperature of which is preferably between 50 ° C and -60 ° C.
• the grid present at the airlock 4 can prevent the dissemination of product particles if the evaporation rate is important.
• the motor 12 drives the axis 30 in rotation according to the three movements described above.
• the two movements back and forth are alternately repeated during a first cycle.
• the motor 12 drives the axis 30 in rotation according to the third movement of large amplitude so as to move the products of the first compartment towards the second compartment.
• the lock 2b is opened and new products are introduced into the first compartment according to the process described above.
• the compartment between the locks 9a and 9b is under vacuum and the lock 9a is opened and the freeze-dried products are extracted from the evaporation chamber 5 by the unloading chamber 42.
• the lock 9a is then closed and the lock 9b is open to extract the product through the outlet 8.
• the products are introduced into the vacuum lock, and once the lock 9a is closed, the vacuum is broken and the pressure is brought by means of sterile nitrogen at atmospheric pressure before opening the lock 9b.
• the lock 9b is closed and the vacuum is restored in the chamber 42 while waiting for the next load.
• the valve of the lock 4 is closed and the heating means 15, 16 and cooling 17, 18 are stopped.
• water vapor is introduced into the condensation chamber 10 through the steam injection nozzles 31, 32 so as to cause melting of the ice and sterilization of the two rooms 5, 10.
• FIG. 5 illustrates a third embodiment of the invention in which two condensation chambers 10a, 10b are connected to the evaporation chamber 5 by two separate chambers 4a, 4b.
• the two condensation chambers 10a, 10b are substantially identical and each have an ice trap 11a, 11b fed by cooling means 17a, 17b, 18a, 18b as described with the first embodiment of the invention.
• the implementation of two condensation chambers 10a, 10b makes it possible to regenerate one of the chambers while the other operates so as to extract the ice stored in the form of water.
• the first chamber 10a is connected to the chamber 5 by opening the lock 4a while the second chamber 10b is not connected to the chamber 5 by closing the lock 4b.
• the water in the form of ice is trapped in the first chamber 10a during the lyophilization process.
• the airlock 4b When the ice trap 11a of the first chamber 10a is substantially full, the airlock 4b is open and the airlock 4a is closed so as to use the second chamber 10b to trap water vapor.
• the first chamber 10a is depressurized and then steam is injected through the nozzle 32a so as to evacuate the trapped water in the form of ice. The first chamber 10a can then be reused when the ice trap 11b of the second chamber 10b is substantially full.
• each recovery chamber 10a, 10b is connected to a vacuum pump 6a, 6b via a valve 7a, 7b.
• the vacuum is placed in the recovery chamber 10a, 10b.
• the valve 7a, 7b is opened without actuating the corresponding vacuum pump 6a, 6b so as to depressurize the condensation chamber 10a, 10b.
• the injection of steam during the regeneration of a condensation chamber 10a, 10b also serves to sterilize this condensation chamber 10a, 10b.
• the partitions 40a, 40b have two distinct shapes mounted alternately in the evaporation chamber 5.
• the evaporation chamber 5 being cylindrical
• the partitions 40a, 40b are extend radially with respect to the evaporation chamber 5.
• Each partition 40a, 40b is in the form of a disk, a portion forming substantially a quarter of the disk is removed so as to form a notch 39a, 39b.
• Each notch 39a, 39b is intended to allow the passage of products between two consecutive compartments.
• the indentations 39a, 39b of two consecutive partitions 40a, 40b are offset axially with respect to the axis of revolution of the cylinder forming the evaporation chamber 5, as illustrated in FIG. 6a when the motor 12 does not cause the evaporation chamber 5 in rotation.
• the axial offset between the two indentations 39a, 39b of two consecutive partitions 40a, 40b is substantially 90 °.
• the first notch 39a of the first partition 40a is disposed on the left side while the second notch 39b of the second partition 40b is disposed on the lower part of the evaporation chamber 5. It follows that the second partition 40b allows the passage of the product while the first partition 40a retains the products.
• the first notch 39a of the first partition 40a is disposed on the lower part of the evaporation chamber 5 while the second notch 39b of the second partition 40b is disposed on the left side. It follows that the first partition 40a allows the passage of the product while the second partition 40a retains the products.
• a large amplitude movement is synchronized with the opening of the locks 2b and 9a intended to allow the introduction and extraction of products from the evaporation chamber 5.
• the invention thus makes it possible to lyophilize products arranged in bulk in the evaporation chamber 5 and continuously, that is to say without stopping the heating means 15, 16 and cooling 17, 18 between two products to be freeze-dried.
• the energy consumption of the freeze-drying device of the invention is reduced by 20 to 40% compared to the devices of the prior art for the same quantity of products.
• the product being mixed it is more homogeneous and the information collected by the sensors 20, 21, 24 makes it possible to better characterize the product.
• the number of compartments is not limited. It is used to set the output frequency of the product. As every other compartment is used for not having a mixture in two consecutive compartments, the output frequency of the product is calculated as follows: if the residence time of the product is 10 hours, with twenty compartments it is possible to extract all the hours a load of product. With forty compartments and a residence time of 10 hours, it is possible to reduce the output frequency every half hour.
• the output frequency of the evaporator becomes a variable which depends on the number of compartments and the overall residence time in the evaporation chamber 5.
• the residence time of the product in the freeze-dryer can also depend on other factors such as size of the pellets or granules entered and the frequency of the stirring movement.
• the invention also makes it possible to lyophilize products in an automated and sterile manner because the operator has no physical connection to be made at the inlet 1 and the outlet 8 of the evaporation chamber 5. In addition, it is possible to modify the heating conditions between two consecutive compartments in order to improve the lyophilization process.
• the invention has been implemented effectively with an evaporation chamber 5 whose capacity is between 0.01 and 1 m 3 .
• lyophilization can be performed without vacuuming the chambers 5, 10 using the zeodration technique.
• the vacuum pump 6 and the valve 7 can be omitted.
• the freeze-drying device can extract other solvents distinct from water, for example alcohol.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Drying Of Solid Materials (AREA)
• Freezing, Cooling And Drying Of Foods (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2017
  • 2017-04-10 EP EP17719667.2A patent/EP3443286B1/de active Active
  • 2017-04-10 JP JP2018553433A patent/JP6894450B2/ja active Active
  • 2017-04-10 WO PCT/FR2017/050848 patent/WO2017178740A1/fr not_active Ceased
  • 2017-04-10 CN CN201780022441.3A patent/CN108885057B/zh active Active
  • 2017-04-10 US US16/088,874 patent/US10627162B2/en active Active
  • 2017-04-10 CA CA3057608A patent/CA3057608C/fr active Active
• 2018
  • 2018-10-07 IL IL262182A patent/IL262182B/en unknown

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