Abstract:
A blender device including a rotor designed to engage with a motor device to be rotated; and an annular ring enclosing the rotor and having at least one axial orifice and a plurality of radial orifices for the passage of the blend. The blender also includes an admission duct for admitting particles intended to be incorporated into the blend, leading into the interior of the annular ring. The blender also effectively dispenses particles in a blend by introducing the particles with a high flow and decreasing product losses.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The invention concerns a blender device, a blender assembly equipped with such a device and a method for producing a preparation. 
     The device as well as the blender assembly are particularly intended for producing a preparation, and more particularly dispersing particles in a preparation. 
     BACKGROUND OF THE INVENTION 
     In the prior art, it is known to produce preparations by blending substances in a vat and introducing powdered particles into the vat in order to incorporate them in the blend. 
     Such preparations are commonly produced for pharmaceutical, cosmetic or agri-food industry applications. For pharmaceutical or cosmetic applications, the incorporated particles can in particular form the active ingredient of the composition and must then be incorporated into the blend in very precise proportions. 
     In order to produce these preparations, blender assemblies are known. According to the most widespread technology, these include a vat, kept in depression and intended to receive the blend, a rotor including blending blades and engaging with motor means in order to be rotated, and a stator including an annular ring surrounding the rotor and having radial orifices for the passage of the blend radially projected by said rotor. 
     Two methods are commonly used to incorporate the particles into the preparation. 
     According to a first method, illustrated in  FIG. 1 , the particles are introduced by suction into the vat kept in depression via an admission duct opening into the bottom of the vat, laterally to the rotor-stator unit. The admission duct is equipped with a gate making it possible to control the introduction of particles into the vat. The particles to be incorporated in the blend circulate in the vat approximately following the path of the arrows f 1 . However, in this case, the introduction flow of the powder is directly related to the level of vacuum in the vat. Also, for a given gate, it is necessary to increase the vacuum to increase the flow of particles introduced. However, depending on the viscosity of the blend in the vat, an excessively high vacuum level causes too fast a passage of the particles through the blend and the suctioned particles stick against the upper portion of the vat; this creates cleaning and loss-of-product problems. 
     According to a second method, illustrated in  FIG. 2 , the blender assembly is equipped with an outside hose allowing a recirculation of the preparation. In this embodiment, the powder particles are introduced into the vat via an admission duct opening into the outside hose. However, this method poses problems in terms of cleaning the outside recirculation hose. Furthermore, the introduction flow of the powder is limited by the dimensions of the outside hose and by the circulation flow therein. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The invention aims to resolve these problems by proposing a blender device making it possible to effectively disperse particles in a blend, to introduce said particles with a high flow and to decrease product losses. 
     The device according to the invention can also be used in a blender assembly that is easy to clean. 
     To this end, and according to a first aspect, the invention proposes a blender device comprising:
         at least one rotor intended to cooperate with motor means in order to be rotated; and   an annular ring surrounding the rotor and having at least one axial orifice and radial orifices for the passage of the blend; and   an admission duct for admitting particles intended to be incorporated into the blend, opening inside said annular ring.       

     Thus, the particles of powder are dispersed effectively because the introduction of the particles is done directly in the turbulence zone. 
     Furthermore, the introduction of the powders can be more significant because it is possible to increase the vacuum level in a vat equipped with such a device without, however, the particles being projected against the upper portion of the vat. 
     Moreover, the blender assembly equipped with such a device does not require a hard-to-clean outside recirculation hose. 
     Lastly, the blender device according to the invention makes it possible to decrease the implementation time of the device to completely incorporate particles into the preparation. 
     Advantageously, the device includes an engine block including the rotor, the annular ring, motor means, and a shaft connecting the rotor to the motor means, and said engine block supports at least one portion of the admission duct. 
     Thus, the device is compact and easy to install on a blender assembly. 
     Advantageously, the admission duct is equipped with a gate supported by the engine block. The gate is preferably pneumatic flap gate. 
     In one embodiment, the engine block comprises means for fixing to a blender vat in order to facilitate the installation of the device on the vat of the blender assembly. The fixing means are pressure sealed in order to allow the depression of the blender vat equipped with such a blender device. 
     Advantageously, the admission duct passes through said means for fixing to a vat. Thus, the vat equipped with such a blender device only has a single passage for the installation of the rotor, the annular ring and the admission duct. 
     In one embodiment, the engine block includes two coaxial rotors. This embodiment makes it possible to further decrease the production time of the preparation. 
     In one preferred embodiment, the rotor(s) include(s) blender blades arranged to suction the blend through the axial orifice of the annular ring and project it radially through radial orifices of the annular ring. 
     Advantageously, the admission duct opens near the radial end of the blending blades of the rotor. Thus, the introduction of the particles in the vat is favored by the radial movement of the blend. 
     According to a second aspect, the invention concerns a blender assembly comprising a vat intended to receive a blend and a blender device according to the first aspect of the invention. 
     Advantageously, the blender assembly is equipped with means for creating a vacuum inside the vat. Thus, the particles coming from the admission duct are suctioned. 
     Lastly, according to a third aspect, the invention concerns a method for producing a preparation comprising:
         a blending step using:
           a rotor rotated by motor means; and   an annular ring surrounding the rotor and having at least one axial orifice and radial orifices for the passage of the blend;   
           a step for introducing particles into the vat via the inside of the annular ring in order to incorporate the particles into the blend.       

     Advantageously, the vat is kept in depression in order to allow the introduction of the particles by suction. 
     According to one embodiment, one blends at least two non-miscible substances in order to produce an emulsion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other aims and advantages of the invention will appear during the following description, done in reference to the appended drawings, in which: 
         FIGS. 1 and 2  are diagrammatic views illustrated blender assemblies for the production of an emulsion according to the prior art; 
         FIG. 3  is a diagrammatic view of a blender assembly according to the invention; 
         FIG. 4  is a diagrammatic view of a rotor and an annular ring; 
         FIG. 5  is a diagrammatic radial cross-sectional view of a blender device; 
         FIG. 6  is a diagrammatic radial cross-sectional view of a blender device comprising two rotors; 
         FIG. 7  is a diagrammatic cross-sectional view of a blender device, according to a first embodiment of the invention, in operation; the arrows show the movement of the blend inside the vat; and 
         FIG. 8  is a diagrammatic view of a blender device according to a second embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 3  diagrammatically illustrates a blender assembly, according to the invention. This assembly comprises a vat  1 , a blender device  14 , admission means  9  and evacuation means  10  for fluids. 
     At least two fluids intended to be blended in the vat  1  are conveyed by the admission means  9 , pass through the vat  1  and are evacuated by the evacuation means  10 . The admission means  9  and evacuation means  10  each include a line for passage of the fluids and a gate  12 ,  13  making it possible to regulate the admission and evacuation flow. 
     The blender assembly is also equipped with means, such as a pump  11 , making it possible to form a vacuum inside the vat  1 . In operation, the depression reigning inside the vat can extend between 0 and 0.99 bar. 
     The blender device according to the invention includes a rotor  2  that rotates inside an annular ring  5 . 
     The rotor  2  engages with motor means  4  in order to be rotated and includes blending blades  3   a ,  3   b ,  3   c ,  3   d  arranged to axially suction the blend and project it radially through the rotor  2 . The rotor  2  is connected to the motor means  4  by a shaft  16  and includes, to that end, a cylindrical bore  17  (see  FIGS. 7 and 8 ) making it possible to connect the end of the shaft  16  to the rotor  2 . 
     The blender device also includes an annular ring  5  surrounding the rotor  2 . The annular ring  5  can be fixed, and will in this case be called rotor, or rotatably mobile (not shown). The ring  5  has an upper axial orifice  18  allowing the passage of the blend suctioned by the rotor  2 . The annular ring  5  also includes, on its periphery, orifices  6  for the passage of the blend projected radially by said rotor  2 . The radial orifices  6  are slits parallel to each other and are separated by portions serving as impact surface. The blend projected by the rotor  2 , through the openings  6 , depending on the radial direction undergo a shearing depending on said radial direction. Moreover, the space between the rotor  2  and the annular ring  5  is small enough to obtain the desired shearing stresses. 
     According to the arrows of  FIG. 7 , illustrating the movement of the blend in the vat  1 , when the rotor  2  is rotated, the blend is suctioned in the axial direction along the arrows f 1  and projected outwardly through radial slits, following the arrows f 2 . The blend is thus forced to flow through the slits of the ring  5 . Advantageously, the blender assembly can comprise one or several turbines, not shown, arranged inside the vat  1  and arranged to drive the blend, along the direction of the arrows f 2 , toward the axis of the rotor  2 . 
     In the embodiment shown in  FIGS. 7 and 8 , the blender device is realized in the form of an engine block, comprising the motor means  4 , the shaft  16 , the rotor  2 , the annular ring  5  and a casing  18  making it possible to house the shaft  16 . 
     The device includes an admission duct  7  for admitting particles in the vat  1 . According to the invention, in order to disperse the particles effectively in the blend, the admission duct  7  opens directly inside the annular ring  5 . The other end of the admission duct  7  is intended to be submerged in a particle reservoir so as to ensure the suction of the particles. The introduction of the particles inside the vat  1  is ensured by the depression reigning inside the vat  1  and a gate  8  equipping the admission duct  7  makes it possible to regulate the introduction flow of particles in the vat  1 . Advantageously, the admission duct  7  opens near the radial end of the blades  3   a ,  3   b ,  3   c ,  3   d . Thus, the introduction of the particles is encouraged by the radial projection of the blend during the rotation of the rotor  2 . 
     In the illustrated embodiments, the gate  8  is fixed directly to the casing  18  of the engine block. The gate  8  used is for example a pneumatic flap gate  23 . 
     In the embodiment detailed in  FIG. 7 , the annular ring  5  is supported by a circular plate  15 . This plate  15  is intended to be inserted into a central cavity of the vat  1 . In order to ensure sealing, the side wall of the plate  15  is equipped with a circular groove  19  and an O-ring housed in said circular groove  19 . The ring makes it possible to ensure the sealing of the vat against liquid and pressure. 
     In order to allow the transmission of the rotational movement of the motor means  4  toward the rotor  2 , the shaft  16  passes through a central bore formed in the plate  15  and is guided in rotation by guide bearings  20 ,  21  supported by the casing  18 . Moreover, the casing  18  supports an O-ring  22  making it possible to seal the central bore of the plate  15  against gas and liquids. 
     Moreover, the plate  15  includes an admission orifice for admitting the particles that is connected to the admission duct  7  of the particles. In the closed position, the valve  23  of the gate  8  closes the passage between the admission duct and the admission orifice, whereas in the open position, illustrated in  FIG. 7 , the valve  23  of the gate  8  frees the space for the passage of the particles. In one advantageously embodiment of the invention, the gate  8  can be equipped with sensors making it possible to detect the position of the valve  23 . 
     The engine block also includes means for sealed fixing to the vat  1 , not shown, arranged between the rotor  2  and the admission duct  7 . To that end, the plate  15  is for example made integral with the vat  1  by welding, or using screws inserted through orifices formed in the plate  15  and engaging with orifices formed in the vat  1 . 
     The admission duct  7  passes through the fixing means. Thus, the vat  1  only includes a single opening for the passage of the admission duct  7  of the rotor  2  and the annular ring  5 . 
       FIG. 8  illustrates a blender device according to a second embodiment, comprising two coaxial rotors  2   a ,  2   b  intended to rotate in opposite directions. 
     To that end, the engine block includes an outer shaft  16   b  rotatably mounted on the casing  18  using bearings  24  and engaging with the outer rotor  2   b , and an inner shaft  16   a  coaxial to the outer shaft  16   b , guided in rotation on the outer shaft  16   b  using bearings  25  and cooperating with the central rotor  2   a . The two shafts  16   a ,  16   b  cooperate with motor means  4  so as to be driven in the opposite direction. The rotational speed of the shafts  16   a ,  16   b  is in the vicinity of 3000 rpm. 
     According to the invention, in order to produce the preparation, one introduces at least two substances into the vat via the admission means  9  and drives the rotors  2 ,  2   a ,  2   b  of the blender device. The vat  1  is kept in depression by the pump  11 . 
     The gate  8  is subsequently displaced in the open position, such that the particles coming from the admission duct  7  are suctioned via the inside of the annular ring of the stator  5 , inside the vat  1 . The gate  8  is then displaced toward its closed position when the desired quantity of particles has been introduced. 
     When the particles have been integrated into the preparation, the latter is evacuated via the evacuation means  10 . 
     In one specific embodiment, one blends two non-miscible substances in order to obtain an emulsion. 
     The invention is described above as an example. It is understood that a person skilled in the art can produce different alternative embodiments of the invention without going beyond the scope of the invention. 
     In particular, one may notably provide for forming the admission duct  7  for admitting particles inside the motor shaft  16 .