FR2475419A1 - PROCESS AND APPARATUS FOR MIXING UO2 POWDERS AND A SECOND TYPE OF POWDERS - Google Patents

Abstract

PROCESS PROVIDING A MORE HOMOGENEOUS MIXTURE. IT INCLUDES: A) THE INTRODUCTION OF A FIRST POWDER CONSTITUENT IN A WATERPROOF TANK 13; B) THE REALIZATION OF A FLUIDIZED BED OF THE FIRST CONSTITUENT POWDER IN THE TANK 13; AND C) THE INTRODUCTION OF A SECOND POWDER CONSTITUENT UNDER PRESSURE INTO THE TANK 13, BY BREAKING THE SECOND POWDERING CONSTITUENT A DEFLECTOR PLATE 21 PLACED INSIDE THE FLUIDIZED BED TO DISPROVE THE SECOND POWDER CONSTITUENT THERE INTO UNIFORMLY THE SECOND POWDER CONSTITUENT. APPLICATION TO NUCLEAR FUEL POWDERS.

Description

The invention relates to improvements in the powder mixture of

  UO2 and a second type of cohesive powders using a fluidized bed mixer, and in particular an improved method and apparatus for transforming a heterogeneous mixture of solid UO2 powders

  and a second type of cohesive powders in a homogeneous blend.

gene.

  In the past, the mixture of solids has been

  particulates in different ways. We used

  mechanical mixers of several types, such as

  barrel rollers, ribbon mixers, and high shear mixers. Blow-bed mixers and fluidized bed mixers were also used. In the prior art, UO2 powders were initially mixed with

  mechanical mixers of the barrel type. This type of

  langeur did not prove satisfactory for the production

  mixed lots meeting certain requirements of homogeneity

  born of UO2 powders. This non-compliance with the requirements of homogeneity is thought to arise from the presence of zones

  stagnant or dead inside fluidized beds of

  which are homogenized in the mixer and

  problems of segregation occurring during the unloading

  ment. U.S. Patent No. 4,168,914 discloses

  wrote an improved bubbler fluidized bed mixer.

  This mixer removes the large dead zones encountered

  in bubbling fluid bed mixers of the prior art

  with an apparatus containing the heterogeneous powders.

  genes, and preferably the UO2 powders, which must be mixed, and it comprises a mixing vessel in the form of

  plate, oriented vertically, - provided with a grid of fluids

  placed at the bottom of the container. In accordance with U.S. Patent No. 4,168,914, the fluidization grid comprises a row of pyramid shaped hoppers.

  generally downwards, all having walls that converge

  in a conical opening. We have more

  gas orifices for directing a flow of fluidizing gas upwardly at the bottom of each

  hoppers. The fluidizing gas is fed to each of the ori-

  these at a speed sufficient for gas bubbles to

  fluidization rise through the powder mixture and

  powders, stirring the powders until a homogeneous mixture of powders is obtained. The combination of the linear network of hoppers and gas ports removes the dead zones encountered with the models

  Prior art of bubbling fluidized bed mixers.

  However, none of the devices known from the prior art

  for the mixing of fine and cohesive powders in a fluidized bed mixer could not meet the requirements

  homogeneity of the products for the homogenisation of

  of UO2 powders and a second type of powders

  both very different physical properties. More particularly

  In particular, because of their cohesive nature, certain powder mixtures of the second type, including hydrophobic, hydrophilic or hygroscopic powders, easily form large agglomerates, leading to poor

  dispersion. In addition, certain agglomerates of low density

  The first UO2 powders will disadvantageously combine or separate in a fluidized bed mixer because of the stagnant or dead zones that exist at the bottom of the fluidized bed. In addition, for certain gas flow rates used during the introduction of powder mixtures of the second type,

  there has been a lack of uniformity in the mix of

  ders. We benefit from the advantages of the invention by using

  an advanced fluidized bed mixer, a rotary grinder

  billon and an ejector, all connected by a transmission system.

  classic pneumatic port. The fluidized bed mixer

  takes a vertically oriented mixing tank provided with a fluidization grid placed at the bottom of the tank. The fluidization grid comprises a row of hoppers in the form of

  pyramids, each presenting at their base a series of

  these intended to receive and direct jets of flue gas

  upwards in divergent swirls along the walls of each of the hoppers. At least one device of the type

  impact plate comprising a baffle plate is placed

  above the row of hoppers in the form of pyramids,

  near the base of the fluidized bed in the mixing tank.

  A mixture of a second powder component and gas is introduced under pressure into the impact device in which

  the deflector plate uniformly disperses the second

  powder in the swirling fluidized UO2 powder bed initially contained in the vertically oriented mixing vessel. It should be understood that the term second material, second powder material or second powder component means that the second material, the second powder material or the second powder component

  can be a mixture of hydrophobic, hydrophilic and

  philes or hygroscopic as defined above, and may include other constituents as a material

  liaison, etc. In addition, the second material, the second

  powdered material, or the second powdered constituent

  be a unique additive such as a hydrophobic, hydrophilic material

  phile or hygroscopic that one must mix so

homogeneous with UO2 powder.

  The second mixture of the powdered component is

  gas to the impact device at a predetermined pressure

  born from a tourbillon mill. In the mix, the second

  constituent powder is formed of agglomerates of a relative size

  very large (about 1200 microns) and the tower grinder

  billon receives the second mixture of the powdered constituent and

  of gas under a predetermined pressure and crushes the

  second powder components having an average particle size of from about 10 to about 60 microns,

  and preferably about 15 microns.

  The second mixture of the powdered component is

  swirl mill gas at a pre-determined pressure

  born from an ejector comprising a feed inlet - in material, a gas inlet for pressurizing the

  system and an internal mixing chamber. The chamber of

  The ejector mixture first coarsely mixes the constituents of the second mixture of powders by the turbulence

  created by the flow of an inert gas introduced under a

  predetermined pressure in the mixing chamber, and

  then pneumatically carries the coarse pressure mixture of the ejector vortex mill. In the vortex mill the particles are ground and mixed again. From the mill, the mixture is introduced under a predetermined pressure into the impingement device and is thereby introduced under a predetermined pressure into the fluidized bed mixer, where it is uniformly dispersed to give a homogeneous mixture with the UO2. powder found there.

  The following description refers to the figures

  FIG. 1 is a perspective view of an embodiment of the apparatus of the present invention comprising a fluidized bed mixer, a vortex mill and an ejector; FIG. 2 is an elevational view of the fluidized bed mixer, where a large number of hoppers are shown and

  an impact device manufactured in accordance with a

  of this invention; Figure 3 is a partial sectional view of the fluidized bed mixer taken approximately along the line 3-3 of Figure 1, looking in the direction of the arrows; Figure 4 is an enlarged sectional view of the vortex mill shown in Figure 1; Figure 5 is an enlarged sectional view of the impact device shown in Figure 3; and FIG. 6, a sectional view of the vortex mill made along lines 6-6 of FIG.

in the direction of the arrows.

  FIG. 1 shows a device for mixing

  powders. This apparatus consists essentially of three

  main features: an advanced fluidized bed mixer

  , an improved vortex mill and an ejector 12.

  The mixture of powdered UO 2 and the second powdered component, which, as indicated above, may be a hydrophobic, hydrophilic or hygroscopic

  in the improved fluidized bed mixer 10,

  Figure 1. As shown in Figure 2, the melange

  The fluidized bed generator comprises a vertically oriented mixing tank 13 provided with a fluidization grid 14 placed at the bottom of the tank. The fluidization grid 14 comprises a

  row of hoppers in the form of pyramids 15 also represented

  2, each having at their base a series of orifices 16, as shown in FIG. 3, designed to receive and direct fluidization gas jets towards

  the top in divergent swirls along the walls of each

  one of the hoppers. The fluidization gas jets create a

  UO2 powder 9, bubbling or traversed by bulbs

  the, with which the mixing tank was initially charged.

  At least one impact device 20 comprising a deflector plate 21 is placed above the row of pyramid shaped hoppers as shown in FIGS. 3 and 5. Referring to FIGS. Impacts 20 has the shape of a cage, causing a deflection effect on a mixture of gases and a second material introduced under pressure into the fluidized bed mixer. The

  device 20 comprises, more particularly the plate de-

  21 indicated above and an upper plate 22. These plates are circular and are kept spaced

  vertically by four supports 23 spaced circularly.

  The top plate 22 has an opening at its center and is suitably attached to a conduit 24. With this arrangement, the mixture of second powder component and gas, indicated previously in the mixing tank and in the fluidized bed is introduced. of UO2 that it contains. Under the effect of the pressure, the second powder hits the baffle plate and a deflecting effect is exerted on this

  powder when it enters the tank, an effect which distributes it

  uniformly throughout the circumference of the impact device and in the fluidized bed of UO2 9 in the vessel. In addition, the conduit structurally supports the impact device at a predetermined location in the fluidized bed near the base of the bed. It should be understood that although only one impact device has been shown and described, several of these devices, arranged in

  one row above the hoppers 15.

  If we now turn to Figures 1 and 4, the

  duct 24 is connected to an outlet 25 on the tower crusher.

  ridge 11 indicated above and thus brings the mixture of gas and second powder material to the conduit 24 from the mill. The vortex mill 11 receives the mixture of

  second material and gas ejector 12 through an inlet 26.

  In the vortex mill 11, the particles of the mixture which grinds from the state of mixture of agglomerates are ground.

  large size (about 1200 microns) to that of pre-mix

  with an average particle size of between

  10 and about 60 microns, and preferably 15 microns.

  When the second powdered component has been milled to a recommended particle size, it is transported under

  pressure the second powder constituent of the grinder to turn-

  in the impact device 20 by a duct 36,

  as shown in Figures 3 and 5.

  The second powder component of the ejector 12 is pneumatically transported to the vortex mill.

as shown in Figure 1.

  The second constituent powder is sucked into the ejection

  vacuum entering the ejector via an inlet opening 33. The gas entering the ejector is an inert gas such as N2 and can be supplied by a gas source 37, as shown in Figure 1. On

  pneumatically conveys the second powder component of the

  jector in the vortex mill 11.

  Referring now to Figure 3, we have

  one of the hoppers located inside the fluidized bed mixer, with respect to the impact device 20 placed

  inside the mixing tank. The fluid bed mixer

  said used in accordance with the present invention is of a

  type generally known in the art and

  takes a vertically oriented mixing tank 13 provided with a fluidization grid 14 placed at the bottom of the container

  10. The fluidization grid 14 comprises a row of tres-

  generally pyramid-shaped pyramids, generally downwards, all of which have walls converging in conical openings. Several valves 17 are used for discharging

  mix the mixed powders, for example

  of UO2 and a second mixture of powders, a valve 17

  being placed at the bottom of each hopper. Each of the three

  mies comprises at its base a series of orifices 16, connected to a gas inlet 18 and to a source of fluidization gas

  by means of tubing and connecting ducts.

  There is a general study of the design of a

  fluidized bed and bubble pad of the prior art, preferably

  considering particle properties, particle size, particle distribution, geometry of the

  vessel, the superficial velocity of the gas, and the trajectories

  Fluidization and Particle Fluid Systems by Frederick A. Zenz and Donald F. Othmer; Reinhold Chemical Engineering Series,

  Reinhold Publishing Corporation, New York, 1960.

  The fluidized bed mixer of the present invention

  differs from fluidized bed mixers of the prior art

  in that it comprises at least one impact device in the vicinity of the fluidization network, as shown in FIGS. 2 and 3. Although only one impact device has been shown, it should be understood that a series of impact devices can be used in the practice of this invention. The impact device, as shown in FIGS. 3 and 5, has a cage-like structure comprising an inlet conduit 24, a

  circular deflector plate 21, a circular plate

  22 and supports 23 connecting the upper plates

  re and bottom of the impact device and now

  spaced vertically. The particular construction of the dis-

  positive impact makes it capable of deflecting

  and decreases the rate and pressure of penetration of the second powder mixture introduced into the fluidized bed mixing tank. When the second mixture of ground powders from the vortex mill enters the fluidized bed mixer, the action of the impingement device allows wide dispersion of the second powder mixture in the UO 2 powder, and a mixture of

homogeneous powders.

  Referring now to FIGS. 1 and 4, the second mixture of powders is introduced into the vortex mill 11 via the inlet 26 of the vortex mill, and

  it passes inside by a feed funnel 27.

  The system of. vortex mill bearings allows it to operate under high pressure (> 6.89.10-3 daN / mm2), for

  allow the injection under pressure of the gas and the second

  powdered material in the lower part of the fluidized bed mixer. The vortex mill bearing system allows it to operate under high pressure, allowing

  high flow inside the pneumatic transport system

  which reduces the agglomeration of occlusions of the second material

  after the grinding when the gas and the second material

  powder are fed to the fluidized bed mixer.

  When the second mixture of powders passes through the enton-

  the feed black 27 of the vortex mill 11, it comes into contact with a spreading device 30 at the bottom of a centrifugal rotor. When the second powder mixture comes into contact with the surface of the spreading device, the

  particles are accelerated to reach

  around 213 m / s by the centrifugal movement of the rotor

  around 20,000 rpm. The particles are propelled radially outwards by the canals

  28 formed by the lower spreading device and the

  that superior rotor and violently hit blocks of

  tungsten carbide 32 placed approximately on the

  lower spread device 30. Where

  come into contact with the tungsten carbide blocks, the particles of the second mixture of powders are crushed, then

  transported under pressure outside the tower crusher

  In the fluidized-bed mixer 10, it is understood that the grinding of the particles of the second type of powders can be carried out by any suitable device or mill and that the present invention is not suitable. not limited to the use of a tourbillon mill. The ejector 12, as shown in FIG. 1, is of a conventional model, comprising a feed inlet

  material 34, a gas inlet 33, and a chamber of

  internal lange which initially mixes the constituents of the second powder mixture by turbulence caused by the flow of inert gas from a gas source 37 within the mixing chamber. As previously indicated, the particle size of the second mixture is of the order of about 1200 microns. The ejector realizes, in

  Moreover, the pressurization of the duct system 36, required

  to the operation of the entire measuring apparatus

  lange. The outlet 35 of the ejector is connected directly to the inlet 26 of the vortex mill by the duct system 36, so as to introduce the second mixture of powders into the vortex mill as shown schematically in FIG. details of the ejector described above are not part of this invention and the ejector

  may be of any type appropriate for the introduction

  initial introduction of the second type of material into the

  mixture, for example of the type 264 used in the preparation of

  of this invention and manufactured by AMETK Inc., Cornwells

Reights, PA. 19020.

  The mixing apparatus of the present invention is effective for the homogeneous mixing of powders of very different physical properties with UO 2 powder in a fluidized bed mixer. In operation, the vessel 13 of the bubbling fluid bed mixer is filled with

  UO2 powder by an arrival placed at the top of this recipe.

  with a valve, such as a butterfly valve (no

  shown), to prevent the escape of powders

  in the mixing process. The butterfly valve is not part of the present invention and any type of valve can be employed. The tank 13 is first filled to about the same height with a mixture of heterogeneous or unmixed powders. The lower half of the tank

  13 thus serves as a mixing chamber while the upper half

  serves as a gas reservoir where the powders

  in the fluidization gas can be deposited.

  In this type of mixer, the mixing of the particles is carried out by fluidization gas bubbles emitted by the series of openings 16 placed at the base of the tank, maintaining inside the tank a pressure included

  between about 6.89.10 daN / mm and about 34.45.10 daN / mm.

  Bubbles of gas rise from the openings to the top of the bed, traversing the whole bed, in large zigzag sweeping movements. When a bubble forms, the contiguous particles slide around its upper part and down, towards

  its lower cavity, so that the bubble rises. The parties

  cules lying directly above the bubble are

  pushed upwards while others are pushed

  and some slide into the lower part of the bubble, filling its trajectory. A rising bubble

  spreading particles radially in all

  erections. When a given bubble rises, the particles fill

  wrinkling its lower cavity are slightly less packed

  that the particles immediately outside the trajec-

  bubble. The following bubble approximate amount-

  in this region will follow a trajectory through the least packed particles, just next to the trajectory of the first bubble. Each of the successive bubbles will therefore tend to rise to a different place, mixing

  other particles with previously mixed particles.

  As more and more bubbles rise through the bed of particles small contiguous bubbles gather to form larger bubbles. This action, with the movement of

  bubbles to the low pressure regions, cause a

  wide sweeping zigzag bubble causing vertical as well as horizontal convection mixing. The bubbles escaping at the top of the bed of particles disperse a little UO2 powder in the gas tank at the top of the mixing tank 13. However, the compressed gas escapes from the bed of particles by intermittent puffs. These intermittent flushes of gas give the opportunity to particles that would normally be entrained in the gaseous stream,

  fall back into the bed of particles, instead of being

  born and swept with the fluidizing gas. It is important to

  that although it occurs in the fluid bed mixer,

  described herein, the circulatory mixture indicated above, there is actually no mass movement of the bed of particles, like that which exists in a

blowing bed mixer.

  After the initial mixing of the second powder mixture in the ejector, the entrained mixture in the inert gas is conveyed under pressure to the feed port 26.

  vortex mill 11 and inside the crusher

  Billon by the funnel of feeding. When the second powder mixture slides into the vortex mill feed funnel, it falls on the surface of a device

  spreading element comprising a pyramidal convex central portion

  dale, nipple-shaped which gradually tilts outwards. The surface of the spreader acts in combination with an upper rotor plate that passes through the feed funnel. The surface of the rotor plate is the image in a mirror of that of the spreading device, and radial channels 28 are thus obtained which shrink.

  gradually and lead to a continuous circular

  to the circular blocks 32, on the circumference of the radial channels formed by the surface of the spreading device and the rotor plate. The spreading device rotates at a speed of about 20,000 rpm, and this force, in combination with the system penetration pressure

  ducts has the effect of pushing the second mixture of

  particles in the inert gas, through the radial channel and strike the tungsten carbide blocks at a velocity of about 213 m / s, which results in a decrease in the particle size of the second mixture of powders. about 1200 microns to a mean diameter of between about 5 and

  about 60 microns, and preferably about 15 microns.

  The second micron-diameter particle reduction powders recommended in the advanced vortex mill are now in a form suitable for mixing with the UO 2 powder.

  contained in the improved fluidized bed mixer.

  The second mixture of powders entrained in the inert gas leaves the vortex mill by an unloading device 25 shown in FIG. 2, and is

  carried by the conduit system 36 at the entrance to the

  24. The second mixture of constituents

  dre enters the fluidized bed mixer by the

  impact tube placed in the vicinity of the base of the fluidized bed and preferably about 60.96 cm above the grid 14 or vertices of the hoppers 15 in the form of directed pyramids

down.

  The second mixture of powders enters the inlet of the

  impact device 24 at a pressure of between

-4 2

  20.67 and 34.45.10 daN / mm, and preferably about

  24,12.10-4 daN / mm2 and comes in contact with the deflector plate

  21. The cage-like structure of the device

  pacts has a deflecting effect and, in connection with the

  deflector, causes a decrease in the force that causes the second mixture of powders to enter the mixer at

  fluidized bed under a pressure of about 13.78.10 daN / mm 2.

  The impact plate uniformly distributes or disperses the second powder mixture in the first fluidized bed

  powder component in the fluidized bed mixer.

  The mixing process of the second type of coherent powders

  and the UO 2 powder starts with the actuation of the ejector 12, and thus the pressurization of the conduit system 36 of the second powder mixture and the vortex mill 11. fluidized bed mixer 10 to circulate randomly

  the UO2 powder contained in the fluidized bed mixer.

  The ejector is put into action first to avoid any

* 247541 9

  leakage of the UO2 powder contained in the fluidized bed mixer in the pneumatic conduit system36 by the

impact device 20. After actuating the ejector, injecting an inert gas as

  N2 at the inlet of gas at a pressure of about 172.3.10 4 daN / mm2, the second pre-cooled powder material is introduced simultaneously into the ejector at the feed inlet 34, o it is drawn into the internal mixing chamber and roughly mixed under the effect of the turbulence created by the flow of gas entering this chamber under a lower pressure than

-4 2

  approximately 34.45.10 daN / mm The second type of materials which are to be mixed as hydrophilic or hygroscopic hydrophobic materials are usually described. Because of their cohesive nature, they can easily form large agglomerates.

  which produce a weak dispersion.

  Hydrophobic materials such as zinc stearate, oils, fats and waxes do not dissolve in water, but adhere to each other. To mix

  this type of material, it is necessary to reduce the size of

  glomerates before they can achieve the desired dispersion.

  Hydrophilic materials tend to absorb water and bind. Materials like carbohydrates

  (starch, vegetable gums, etc.) and protein

  plexes fall into this category. It is also necessary

  the particle size of these materials before obtaining

create an adequate mixture.

  Inorganic materials, among which mention may be made of ammonium bicarbonate, ammonium oxalate, calcium chloride, and zinc chloride, form a third category of so-called hygroscopic materials. These

  substances absorb moisture from the air. More specifically

  deliquescent materials are hygroscopic powders

  spikes of soluble chemical salts in dissolving water

  wind in the water absorbed in the air. These materials are different

  need to be handled in a dry state.

  The second mixture of powdered materials having been

  coarsely mixed in the ejector is transported tire-

  at a pressure of between 6.89 and 20.67.

  daN / mm and preferably about 13.78.10 daN / mm in the vortex mill, to be milled to a recommended particle size. The vortex mill has the effect of increasing the pressure by about 13.78. 10 daN / mm

  and as a result the mixture is transported from the swirl mill to

  lon to the mixing vessel at a slightly higher pressure.

  Then, as mentioned above, this second

  The mixture of ground powdered materials is transported pneumatically

  under pressure to the impact device inside the

  fluidized bed mixer, which together with the barbed bed

  the first mixture of powdered material, and in this

  case of UO2 powder, homogenizes the first and second

swaddles of powdered materials.

  When a homogeneous mixture of the UO2 powder and the second powder mixture is obtained, it is discharged through the hoppers by means of several valves, a valve being placed at the opening of each of the hoppers. These valves serve as an outlet for the mixing vessel when a homogeneous powder mixture is obtained. When the mixing process is complete, the mixed powder is quickly and efficiently discharged in accordance with the US patent.

of America No. 4,182,383.

Claims (16)

R E V E N D I C A T IO N S   1. Process for homogenizing a mixture of ingredients   powder killing, characterized in that it comprises:   (a) the introduction of a first constituent in a sealed tank (13);   b) the realization of a fluidized bed of the first con-   powdering in the tank (13); and c) introducing a second powdered component under pressure into the vessel (13) by striking a second baffle plate (21) with the second powder component positioned within the fluidized bed to uniformly disperse the second constituent powder.   2. Process for homogenizing a mixture of constituents   Powdered dusting agents according to claim 1, characterized in that it further comprises: a) grinding the second mixture of powdered constituents in a mill (11); b) transporting under pressure the second mixture of ground powder constituents from the mill to the sealed vessel; and   c) the shock of the second mixture of constituents   crushed against a deflector plate (21) placed in   fluidized bed of the first powdered constituent and the   uniform dispersion of the second mixture of constituents in   dre in the first mixture of powder constituents contained in the tank to homogenize the first and second mixture of powders.   3. Process for homogenizing a mixture of ingredients   Powdered killing agents according to claim 1, characterized in that it further comprises: a) introducing a gas into an ejector (12) to initiate pressurization;   (b) then the addition of a second mixture of constituents powdering in the ejector;   (c) the mixing of the gas and the second mixture of   pumping powder under pressure in the ejector;   (d) the transportation of the gas and the second mixture of   powdering agents under pressure to the mill (11), and milling the second powder component mixture into the mill; e) transporting under pressure the gas and the second mixture of ground powder constituents from the mill to the sealed tank (13); and f) impacting the second mixture of milled powder components against a baffle plate (21) positioned within the first powdered fluidized bed and the uniform dispersion of the second powdered component mixture in the first component mixture. powder in the tank to homogenize the first and the second mixture of powders.   4. Method according to one of claims 1 to 3, characterized   in that the powders are UO2 powders and a   second powder component having hydrophilic properties   phobic, hydrophilic, or hygroscopic, and in that it   takes: a) the introduction of UO2 powder in a sealed tank (13); b) the production of a fluidized bed of UO2 powder in the sealed tank; and (c) the uniform dispersion of the second constituent   powder in the fluidized bed by the introduction of the second con-   depressurized powder in the tank, by the impact of the second powder component against a baffle plate   (21) placed inside the fluidized bed.   5. Method according to claim 4, characterized in that the second constituent powder has, when   introduced into the fluidized bed, an average size of   ticules between about 10 and about 60 microns.   6. Method according to one of claims 4 or 5,   characterized in that the second powder component   when introduced into the fluidized bed, a   average particle size of about 15 microns.   7. Method according to one of claims 1 to 6,   characterized in that it further comprises: a) creating a fluidized bed of a first powder component in the sealed tank where the pressure is between about 6.89 × 10 4 daN / mm 2 and about 34.35 × 10 daN / mm2;   (b) the introduction into the tank of a second   killing powder at a pressure of between about 20.67 × 10 -4   daN / mm2 and about 34.45.10 4daN / mm2 by shock of the second   powdering against a deflector plate (21) placed inside the fluidized bed; and c) lowering the pressure of the second component   at a rate of about 13.78 × 10 4 daN / mm 2 by the deflection effect   and dispersion of the plate (21) which disperses uniformly   the second powder component in the fluidized bed.   8. Process according to one of claims 1 to 7, characterized   characterized in that it further comprises: a) grinding the second mixture of powdered constituents in a vortex mill (11); b) transporting the second mixture of ground powder constituents of the vortex mill (11) into the sealed tank (13) at a pressure of about 24.12 × 10 4 daN / mm 2; and   c) the shock of the second mixture of constituents   crushed against a deflector plate (21) placed in   fluidized bed of the first powdered constituent and the   uniform dispersion of the second mixture of constituents in   dre in the first mixture of powder constituents contained in the tank to homogenize the first and second mixture of powders.   9. Method according to one of claims 1 to 8, characterized   in that it still includes   a) introducing a gas into an ejector (12)   to start putting the ejector under a pressure of   about 172.25.10 daN / mm; b) introducing a second mixture of powdered constituents into the ejector;   (c) the mixing of the gas and the second mixture of   powdering at a pressure of less than about 34.45 × 10 4 daN / mm in the ejector; (d) the transportation of the gas and the second mixture of   constituents in powder form at a pressure of between   6.89 × 10 -4 daN / mm and about 20.67 ± 10 daN / mm, from the   vortex mill jector (11) and grinding the second powder component mixture into the mill; e) transporting the gas and the second mixture of ground powder constituents from the vortex mill (11) to the sealed tank (13) at a pressure of about 67. 4 daN / mm 2 and about 34.45 × 10 4 daN / mm 2; and   f) the shock of the second mixture of constituents   ground against a deflector plate (21) placed in the   interior of the fluidized bed of the first powdered component and thereby reducing to about 13.78 × 10 -4 daN / mm 2 of the pressure at which it is dispersed in the first mixture   powder constituent contained in the container for homo-   to generate the first and second powder mixtures.   10. Method according to claim 9, characterized in that it further comprises:   a) the transport of the gas and the second mixture of   powder at a pressure of about 13.78 × 10 -4 daN / mm 2 from the ejector (12) to the vortex mill (11), and grinding the second powder mixture into the mill; and   (b) the transport of the gas and the second mixture of   powdered mill components from the vortex mill (11) to the -4 2   sealed tank (13) at a pressure of approximately 24.12 x 10 mm / mm 11. Fluidized bed mixing apparatus, characterized in that it comprises:   a) a vertically oriented watertight mixing tank- ment (11);   (b) a device for introducing a first   killing powder in the mixing tank;   c) a fluidization grid (14) for carrying out   providing a fluidized bed in the mixing vessel (13);   (d) at least one impact device (20) placed   above the fluidization grid (14) and comprising a deflector plate (21); and e) a device (24) for introducing a second powdered constituent under pressure into the impact device and for directing it against the baffle plate (21) so as to uniformly disperse the second powder component in the first fluidized bed. constituent in powder in the mixing tank.   Apparatus according to claim 1, characterized in that   the impact device comprises circular plates   upper (22) and lower (21) spaced apart, connected by a plurality of circumferentially spaced supports (23) and that the lower circular plate (21) constitutes the plate deflecting.   Apparatus according to one of claims 1 or 2,   characterized in that it further comprises: a) a conduit device (24) for introducing the second powder component into the impact device (20) and directing it against the upper central surface of the deflector plate (21); and   (b) a support device maintaining the   impact at a predetermined distance above the grate (14).   Apparatus according to claim 13, characterized in that   what he still understands a grinding device under pres-   sion (11) for receiving a mixture of gases and   powdered under pressure and effective for grinding and mixing the powdered constituents, and a device (36)   to conduct the mixture of gases and constituents under pres-   sion of the grinding device to the impact device.   15. Apparatus according to claim 14, characterized in that it further comprises: a) an ejector (12); b) a device (33) for introducing pressurized gas into the ejector (12); c) a device (34) for introducing a powder material into the ejector; d) an internal mixing chamber for mixing the gas and the powder material; and e) an outlet device (35) for passing gas and powder material into the grinding device (11). 16. Apparatus according to claim 15, characterized in that it comprises: a) a mixing tank (13) vertically oriented at the bottom of which is placed a fluidization grid (14); b) a cage-shaped impact device (20), mounted inside the mixing tank and comprising an inlet (24) for introducing into the impact device a mixture of gas and powder material under pressure; ; c) a conduit arrangement (.36) for conveying a mixture of gas and pressurized powder material to   the arrival of the impact device;   d) a vortex mill (11) which can function   effectively under high pressure, comprising an outlet port (25) for conveying a mixture of pressurized powder gas and powder material from the vortex mill to the arrival of the impingement device (20) and including an inlet ( 26) for receiving a mixture of gas and powder material under pressure and a device for mixing and grinding the powder material introduced therein;   e) an ejector (12) comprising an arrival of food   material delivery (34), a gas inlet (33), an internal mixing chamber for initially homogenizing a mixture of gas and powder material and an outlet (35); f) a conduit device (36) connecting the grinder inlet (26) to the outlet port (35) of the ejector, for conveying the pressurized mixture of gas and powder material from the ejector ( 12) to the vortex mill (11); and g) a device (37) for putting the device under a predetermined pressure.