WO2019155038A1

WO2019155038A1 - Modular and instrumented spiral mill for performing tests aimed at defining, studying and optimising the micronization of a powdered material

Info

Publication number: WO2019155038A1
Application number: PCT/EP2019/053221
Authority: WO
Inventors: Piero Iamartino; Salvatore MERCURI; Andrea MURDOCCO; Daniele CRIVELLI; Shani Sebastian MALORGIO; Andrea CAMARCA; Berndt JOOST
Original assignee: Micro-Macinazione Sa
Priority date: 2018-02-12
Filing date: 2019-02-11
Publication date: 2019-08-15

Abstract

A modular and instrumented spiral mill (10; 110) for the micronization of a powdered material (P), suitable for performing tests and trials aimed at optimising the dimensional parameters (D, H, d, D1, H1, H2, D2, H3, H4) and process parameters (Qv', Qm', Qv", Qm", VEL) which influence and determine the properties and the quality (DIS) of the micronization of the micronized powdered material (Ρ'), comprising: - a plurality of modular elements or modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113), apt to define the configuration and the dimensions (D, H, d, D1, H1, H2, D2, H3) of relevant and essential zones and parts (30, 31, 32, 33) of the modular and instrumented spiral mill (10; 110); and - one or more sensors or measuring instruments (FL', FL", TP), placed in these essential parts and zones (30, 31, 32, 33) in order to measure the effective process parameters of the modular and instrumented mill (10; 110) in its use and functioning to micronize the powdered material (P); wherein these modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113) are apt to be varyingly composed and/or assembled and/or replaced one with the other so as to compose and form the modular and instrumented mill in a plurality of different working configurations (10; 110). Thanks to this possibility of configuration in a plurality of different working configurations, the modular and instrumented mill (10; 110) allows advantageously the performing of a series of tests and trials of micronization in corresponding different working conditions and with different powdered materials, so as to succeed, through these tests and trials, measuring by means of these one or more sensors or measuring instruments (FL', FL", TP) included in the modular and instrumented mill the effective working parameters of the micronization process and examining the data and the results (DIS) of the tests and trials performed, in composing and forming the modular and instrumented mill in an optimal working configuration (10; 110) apt to optimise the micronization of a specific powdered material (P).

Description

MODULAR AND INSTRUMENTED SPIRAL MILL FOR PERFORMING TESTS

AIMED AT DEFINING. STUDYING AND OPTIMISING THE

MICRONIZATION OF A POWDERED MATERIAL

Technical field of the invention

The present invention relates in general to the field of devices and apparatuses for the micronization of powdered material, that is for the grinding and crushing of powdered materials and similar substances and products in order to transform them into a considerably finer micronized powder, and in particular its object is a new and innovative mill, modular and instrumented, of the jet type with spiral and swirling flow, also referred to simply as spiral jet mill or even more concisely as spiral mill, for the micronization of a powdered material, particularly suitable for a use for performing tests and trials aimed at defining, studying and optimising the dimensional and process parameters which determine the features, quality and overall the results of micronization of the powdered material.

The present invention also relates to a corresponding method for dimensioning and configuring in an optimal manner a mill of the spiral jet type, to be used at industrial level and therefore for mass production on a large scale, to micronize a specific powdered substance or material of interest, more particularly in the pharmaceuticals sector.

Background art of the invention

Micronization is a high-energy process of grinding and crushing and stems from the need and necessity in many industrial applications to reduce a powdered material into a much finer powder.

For example, in the field of the pharmaceuticals industry, there is the need to micronize pharmaceutical powders, typically containing the pharmacological active ingredient, composed of particles having an average dimension of 500-1000 pm, into powders with particles even 100 times smaller, on average of 2-6 pm, with the aim of increasing the therapeutic efficacy of the pharmacological active ingredient, in which the larger particles which are obtained from this operation of micronization have a dimension of 30 pm, while the smaller ones can even reach a fineness of up to 1 pm.

As will be illustrated further here below, a micronization technology which has been and is still broadly used in the current state of the art is based on the use of a vortex of gas, for example air, oxygen or nitrogen, at high speed, usually in transonic/supersonic regime, inside a hermetic chamber which receives the powdered material to be micronized and transformed into a finer powder.

In fact in this way the particles of the powdered material are moved and drawn into the hermetic chamber by the gas vortex at high speed, so as to increase their kinetic energy and therefore cause the crushing thereof, when they come into collision one with the other, into smaller particles and elements.

Micronization of the particles takes place mainly through impact, among the same particles, or the particles with a body in different material and of greater hardness, but can also take place through shearing and rubbing.

Micronization of pharmaceutical compounds and products offers numerous advantages and improvements among which in particular the following are mentioned: an increase in the specific surface of the micronized particles and fragments with consequent increase in their solubility in water;

an increase in bio availability, or, according to the definition given in pharmacology to this feature, both of the fraction of drug administered which reaches the body circulation without undergoing any chemical modification with respect to the total quantity administered, and of the speed at which the drug is made available in the body circulation;

an improvement in the efficacy of the medication which can be assimilated via inhaling.

Another peculiar feature of the micronization process when used in the field of pharmaceuticals is the amorphisation of the medicine, consisting in the fact that, if the collisions between the particles of medicine take place in certain ideal conditions, the particles do not divide but change their crystalline structure into a structure, amorphous in fact, which means that the active ingredient of the drug increases its bioavailability.

The demand for granular and/or powdered materials for the pharmaceuticals industry characterised by particles of increasingly finer dimensions and exhibiting an appropriate grain size distribution has led, over the years, to the development of various systems of micronization based on different working principles, increasingly efficient, and using corresponding apparatuses and systems which implement these different working principles to micronize a powdered material.

For example, among the various micronization systems, currently available, which characterise and are part of the technology of micronization, mention is made of those in which the micronization of the powdered material is obtained by means of the following apparatuses:

a fluidized-bed opposed j et mill;

an oval jet mill;

- a spiral jet mill.

The technology of micronization based on the use of a spiral jet mill is the more recently developed one and is currently the most used and popular in the pharmaceuticals field.

For completeness of information and in consideration of the relevance and direct pertinence of this technology of micronization to the present invention, Figs. 10A and 10B show a typical spiral jet mill, according to the prior art.

As can be seen from Figs. 10A and 10B, this spiral jet mill, denoted overall by M, comprises two chambers denoted respectively by Cl and C2, separated by a separation wall PA, in which in a first chamber Cl, internal, the micronization of a powdered material P takes place, and in the second chamber C2, external, exhibiting a toroidal shape which surrounds the first inner chamber Cl, a gas Gl is made to flow at high pressure.

A carrier gas, indicated by an arrow G2, typically constituted by air, receives the particles of the powdered material P to be micronized from a feed hopper A and transports them to the inner chamber Cl by means of a feed channel B comprising a Venturi tube VE having the function of reducing the pressure in proximity of the outlet zone of the powdered material P from the hopper A, so as to guarantee constant aspiration and feed of the powdered material P to the chamber Cl, where it is micronized.

The feed channel B can be placed tangentially to the outer toroidal chamber C2 or can have a certain angle of incidence with respect to the latter as shown in Fig. 10A.

The two chambers C 1 and C2 are in communication one with the other via a series of nozzles U, appropriately slanted with respect to the radial direction of the inner chamber Cl, which extend through the wall PA which separates these chambers Cl and C2, so that the high-pressure gas Gl which feeds and flows into the outer toroidal chamber C2 is injected, in the form of jets G, via the nozzles U, into the inner chamber Cl, so as to generate in the latter a swirling flow V, with spiral shape, having the necessary energy to draw the particles P and make them impact each other and therefore micronize them.

The expulsion of a powdered material P’, once micronized, by the mill M, is ensured by the motion of the carrier fluid G2 from the interior of the chamber Cl, where micronization takes place, towards the exterior, in the direction of a cyclone or a classifier or a similar device for the separation of the particulate of the powdered material P’, micronized, from the air and its classification as a function of the dimensions of the micronized particles.

Therefore the process of micronization based on a spiral jet mill such as that described previously exploits mainly the collision between the particles and takes place without using moving mechanical elements, yet uses solely a swirling gaseous flow.

Naturally it is of fundamental importance, in consideration of the technical context illustrated previously as also of the current range and availability of various micronization systems, at times also alternative one in relation to the other, to choose the most suitable and advantageous one, that is to choose the system of micronization, jointly with the respective apparatuses, which are capable of supplying the optimal results for the specific application which has to be performed and the specific product or powdered material which has to be micronized.

It is equally important and fundamental, once the system of micronization and therefore the respective micronization apparatus or apparatuses have been chosen, to establish the optimal working parameters of the micronization process, that is those most suitable and advantageous and able therefore to supply the best results for the specific application to be performed and the specific product to be micronized.

Unfortunately, the current technique does not provide effective tools and methodologies to quickly and efficiently establish the optimal operating characteristics and parameters that must be implemented in a micronization plant or equipment in order to micronize a powdered material of interest in an optimal and satisfactory way .

In fact, at least in general terms, in these circumstances the current technique does not go beyond the execution with the existing systems and micronization machines of empirical tests, left free or at most carried out with the support of data and experience acquired in previous tests, in any case without the support of adequate and precise tools able to quickly and scientifically direct the tests towards the correct determination of the optimal micronization parameters.

It follows that, in the current technique, the times taken to establish with sufficient certainty these optimal operating parameters of micronization are rather long and therefore usually involve significant costs.

The present invention is in fact part of the technical context and problems illustrated above and is therefore aimed at meeting the need, particularly felt in the area of the pharmaceuticals industry, to make available useful and effective instruments for optimising the micronization of a powdered material, typically constituted by a pharmaceutical compound.

More particularly, as described here below in a detailed manner and with the support of numerous data and examples, the present invention, taking as a reference the spiral jet mill, model MC150 produced by the Applicant, that is by the Swiss firm Micro- Macinazione SA, shown for the sake of clarity in Fig. 11, the aim is to produce a jet mill, modular and instrumented, apt to constitute a useful and effective instrument for studying and optimising the operation of micronization of a powdered product, typically constituted by a pharmaceutical compound, as regards the definition and the optimisation both of the configuration of the spiral jet mill provided to be used in the effective industrial production on a large scale of the micronized powdered product, and of the effective process parameters which define and influence the results of the operation of micronization of the powdered product.

Therefore, this model MC150 of spiral jet mill having remained in fact substantially unchanged for a long time, the present invention is also aimed at providing useful instruments and a method for configuring in an optimal manner the relevant and essential parts, illustrated in detail here below, of this mill model MC150, offered on the market by the Applicant Micro-Macinazione SA, so as to expand significantly the applications thereof and in particular allow use thereof in order to micronize new and further powdered materials with respect to what has been done to date.

Objects and summary of the invention

Therefore a first object of the present invention is to create a new jet mill, modular and instrumented, which, meeting primarily the needs of the pharmaceuticals industry, allows the performing in a rapid and reliable manner of tests and trials aimed at optimising the working parameters of the operation of micronization of a powdered material, typically constituted by a pharmaceutical compound.

A further object, related to the previous one, of the present invention is also that of creating a jet mill, modular and instrumented, which advantageously can be used, in particular but not exclusively, in the field of the pharmaceuticals industry, in order to perform tests and trials aimed at dimensioning and optimising the configuration of an industrial spiral mill, that is of a mill provided in order to be used on an industrial scale and for mass production in order to micronize a specific powdered material. The abovementioned objects can be considered to be achieved in full by the modular and instrumented spiral mill having the features defined by the independent claim 1 and by the corresponding method in order to dimension an industrial spiral jet mill, that is a mill for a use for micronizing a powdered material in a typical industrial production on a large scale, as defined by the independent claim 9.

Particular embodiments of the present invention are defined by the dependent claims.

As more broadly illustrated here below, the modular and instrumented mill of the invention allows the modification separately of most of the factors and of the parameters which determine the performances and the results of the process of micronization.

Therefore, thanks to this versatility, the modular and instrumented mill allows also the performing of a wide variety of tests and trials of micronization in a corresponding broad variety of working conditions, so as to obtain useful and relevant information in order to optimise the process of micronization of a certain powdered material and therefore obtain the maximum quality of the micronized powdered product.

Advantages of the invention

The advantages are numerous and relevant, at least in part already implicitly disclosed previously and associated with the new modular and instrumented mill, according to the present invention and with its use for performing tests and trials aimed at optimising the various working parameters of the operation of micronization of powdered material, such as those listed here below purely by way of an example:

a precise and exact determination of the optimal working conditions of micronization, that is of the working factors and parameters which are at the basis of an optimal micronization, performed by means of a spiral jet mill, of a powdered material of interest;

therefore also the possibility of determining the conditions of maximum production efficiency and of greater yield of the operation of micronization of a specific powdered material of interest by means of a spiral jet mill; an advantageous use, in particular in the context of a laboratory for supporting an effective production on industrial scale of a micronized powdered material by means of a spiral jet mill in order to establish the best and optimal working conditions to be adopted in this industrial production on a large scale with the spiral jet mill;

therefore lower costs in micronization at an industrial level;

a significant saving in the costs of design and set-up of a spiral jet mill intended for micronization at industrial level of a specific powdered material, in particular constituted by a pharmaceutical compound.

- an effective and precise control of the fineness and of the dimensions of the particulate obtained with the operation of micronization;

an exact and correct detection of the factors and of the parameters, connected to the operation of micronization, which determine the features, the grain size distribution and the quality of a micronized powdered material;

- the possibility, thanks to the instrumentation which equips the modular mill, of collecting relevant data and information to be used in order to simulate the process parameters and the fluid dynamic phenomena which determine the results of the operation of micronization of a powdered material.

Brief description of the drawings

These and other objects, features and advantages of the present invention will be made clear and evident by the following description of some of its preferred embodiments, given by way of a non-limiting example with reference to the accompanying drawings, in which:

Fig. 1 is a sectioned view which shows in a first working configuration a modular and instrumented spiral mill, according to the present invention, for performing tests and trials aimed at optimising the micronization of a powdered material, and its division into modular elements or modules which can be composed one with the other in order to make up the modular and instrumented mill; Figs. 2A-2C are sectioned views of the modular and instrumented spiral mill, according to the present invention, in further working configurations;

Fig. 3, divided into sections (a)-(l), shows, in isolated form, some of the modules, which can be composed and assembled one with the other in a variety of configurations, of which the modular and instrumented mill of the invention of Figs. 1 and 2 is composed;

Fig. 4, divided into sections (a)-(l), shows in detail, as integration of Fig. 3, the dimensional parameters defining the configuration and the dimensions of essential parts of the modular and instrumented mill of the invention, in turn corresponding to the modules which can be composed one with the other in order to compose the same modular and instrumented mill;

Figs. 5A-5E show some types of sensors and measuring instruments included in the modular and instrumented mill of the invention and their placing in the same modular and instrumented mill;

Figs. 6A and 6B are respectively a diagram of a Pitot tube and a view of the zone in which the Pitot tube is coupled with an upper lid of the modular and instrumented mill of the invention;

Fig. 7 is a schematic view which shows the points and the zones in which the measurement is taken, inside the modular mill of the invention and by means of the Pitot tube of Figs. 6A and 6B, of the speed of the swirling flow of the air and the speed vectors obtained with these measurements;

Figs. 8A and 8B show two examples of simulation respectively of the distribution of the pressure and of the speed of the swirling flow of air in the modular and instrumented mill of the invention;

Fig. 8C shows an example of distribution of the dimensions of the micronized particles obtained with the modular and instrumented mill of the invention, during the performing of the tests to optimise the micronization of a powdered material.

Fig. 9, divided into sections (a)-(n), shows the various phases of the assembly of the modular and instrumented mill of the invention in a generic configuration for performing the tests aimed at optimising the micronization of a powdered material;

Fig. 9A, divided into sections (a)-(f), shows some examples of change, in particular using modules constituted by appropriate shims, of the configuration of the modular and instrumented mill of the invention;

Fig. 9B is a working block diagram which illustrates the use of the modular mill of the invention to assemble it and compose it in a plurality of test conditions and configurations, in which to perform a series of tests with the modular mill, in order to succeed in defining an optimal configuration of the same modular mill apt to optimise the features of the micronized powdered material;

Figs. 10A and 10B show in schematic form and in section a typical spiral jet mill, according to the prior art; and

Fig. 11 shows a model MC150 spiral jet mill, produced by the Applicant Micro- Macinazione SA, to which reference is made by the modular and instrumented mill of the invention in that both exhibiting a similar and corresponding configuration.

Description of some embodiments of the modular and instrumented spiral mill of the invention

Referring to the drawings and more particularly to Fig. 1, a modular and instrumented spiral mill, according to the present invention, herein below also referred to concisely as modular mill, for a use for micronizing a generic powdered material denoted by P and more specifically for performing tests and trials aimed at optimising the working parameters of the operation of micronization of this powdered material P, is denoted overall by 10, in a respective first configuration or embodiment.

As already anticipated, the modular and instrumented mill 10 of the present invention has as specific reference and corresponds, as regards its general configuration and its relevant and essential parts, to the spiral jet mill conforming with the model MC150 produced by the same Applicant Micro-Macinazione SA, as shown for the sake of clarity in Fig. 11. Therefore, as will be made clear here below by the description, the modular and instrumented mill 10 of the invention is also apt to be advantageously used to perform a series of tests and trials aimed at dimensioning and optimising the configuration of an industrial spiral jet mill, having a configuration substantially conforming to this model MC150 of the Applicant, provided for a use on an industrial scale and for mass production of a specific micronized powdered material P.

In detail the modular and instrumented spiral mill 10 comprises:

a plurality of modular elements or modules, denoted by 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 and illustrated in detail here below, apt to be composed and assembled one with the other to compose and form the modular and instrumented mill 10, in which these modules 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 define the configuration and the dimensions of relevant and essential zones and parts of the same modular and instrumented mill 10; and

one or more sensors or measuring instruments placed in these essential parts and zones of the modular and instrumented mill 10 in order to detect the working parameters of the same modular and instrumented mill during its use and functioning to micronize the powdered material P, as described in greater detail here below.

According to a salient feature of the present invention, the modules 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 of the modular and instrument mill 10 are apt to be varyingly assembled and/or composed and/or replaced one with the other in order to compose and form the modular and instrumented mill in a variety and plurality of different working configurations, so as to allow both the performing by means of the same modular and instrumented mill 10 of a series of tests and trials of micronization in corresponding different working conditions and with different powdered materials, and the measuring by means of these one or more sensors or measuring instruments included in the same modular and instrumented mill 10 of the effective working parameters relating to the tests and trials of micronization that are performed. Moreover, in the effective use of the modular and instrumented mill 10 and as described in detail here below, the respective modules 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 are provided in order to be varyingly assembled and/or composed and/or replaced one with the other, taking account of the effective values of the working and process parameters that are measured, by means of the instrumentation which equips the modular mill, during the performing of the tests and trials with the same modular and instrumented spiral mill in order to micronize a specific powdered material P, and also assessing whether the micronized powdered material meets and fulfils the required features, so as to compose the modular and instrumented mill in an optimal configuration apt to optimise the micronization of this specific powdered material P.

The relevant and essential parts and zones, of the modular and instrumented mill 10, to which the respective modules 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 correspond, which can be varyingly composed one with the other, are selected, among the various parts and zones whereof the modular mill 10 is composed, in that apt to have a relevant and essential weight in determining the performances of the process of micronization and therefore the end features, such as the fineness and grain size of the particles and their distribution, of the micronized powdered material which is obtained and produced with the same modular mill 10.

Therefore the configuration and the dimensions of these essential zones and parts of the modular and instrumented mill 10 define and correspond also to dimensional parameters which have a relevant function and weight in the process of micronization, performed with the same modular and instrumented mill 10, and in determining the quality and the results thereof.

In detail, the configuration and the dimensions of these essential parts and zones of the modular and instrumented mill 10, in turn corresponding to modules 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 which can be varyingly composed one with the other to form and compose the same modular and instrumented mill 10, comprise:

the general form or configuration of a central micronization chamber 30, provided to receive the powdered material P to be micronized and in which the powdered material P is micronized, and more precisely the height H and the diameter D of the micronization chamber 30 and the fitting radii Rl, R2 between a cylindrical annular wall 30a which delimits laterally this micronization chamber 30 and respectively a lower wall 30b and an upper wall 30c, more particularly both flat, of the same micronization chamber 30;

the number, the diameter d and the slant a, with respect to the radial direction of the micronization chamber 30, of a plurality of nozzles 31, formed through the side annular wall 30a which delimits the micronization chamber 30 and apt to eject into the latter a corresponding plurality of jets G generated by air or another gas Gl, pressurised, fed to an annular chamber 34 which surrounds the micronization chamber 30, so as to determine a spiral and swirling gaseous flow V, converging towards a central zone of the same micronization chamber 30, apt to cause the collisions between the particles and therefore micronize the powdered material P;

the relevant dimensions, such as the inner diameter Dl, the height Hl and the depth H2 of a lower immersion tube 32 apt to receive from the micronization chamber 30 the micronized powdered material, denoted by P’, and to discharge or otherwise a portion thereof downwards in the direction of a recuperator;

- the relevant dimensions, such as the outer diameter D2, the height H3 of an upper immersion tube 33 apt to receive from the lower immersion tube 32 the micronized powdered material P’ and to convey it upwards in the direction of a separator or classifier;

the fitting radii R3, R4 between the lower immersion tube 32 and the upper immersion tube 33 and respectively the lower wall 30b and the upper wall 30c of the micronization chamber 30;

the inclination or slant b, with respect to the radial direction of the micronization chamber 30, and the angular position between two consecutive nozzles 31, of a feed conduit 36 of the powdered material P, transported by a carrier gas G2, to the same micronization chamber 30.

Dimensional parameters considered and which can be optimised with the modular and instrumented mill of the invention

For the sake of clarity, to sum up and integrate what was described previously, the dimensional parameters are listed below, defined by the essential zones and parts of the modular mill 10 of the invention which correspond to the modules 11, 12, 13, 14, 15, 16, 17, 18, 18, 21, 22, 23, 24 provided in order to be assembled one with the other in a variety of combinations and configurations for performing tests aimed at optimising the process of micronization, performed with the same modular mill 10, of a powdered material P: height H of the inner micronization chamber 30;

diameter D of the micronization chamber 30;

fitting radius Rl between the lower wall 30b and the side annular wall 30a of the micronization chamber 30;

fitting radius R2 between the upper wall 30c and the side annular wall 30a of the micronization chamber 30;

height Hl of the lower immersion tube 32;

depth H2 of the lower immersion tube 32;

inner diameter Dl of the lower immersion tube 32;

fitting radius R3 between the lower immersion tube 32 and the lower wall 30b of the micronization chamber 30;

height H3 of the upper immersion tube 33;

outer diameter D2 of the upper immersion tube 33;

fitting radius R4 between the upper immersion tube 33 and the upper wall 30c of the micronization chamber 30;

number and diameter d of the nozzles 31 which emit the gaseous jets G formed by the gas Gl at high pressure fed to the annular chamber 34 which surrounds the central micronization chamber 30; slant a of the nozzles 31 with respect to the radial direction of the micronization chamber 30;

vertical position H4, in the micronization chamber 30, of the nozzles 31 and of an opening 37 of inlet of the powdered material P, fed and transported by the carrier gas G2, into the same micronization chamber 30;

the slant b, with respect to the radial direction of the micronization chamber 30, of the conduit of feeding of the powdered material P, fed by the carrier gas G2, to the same inner micronization chamber 30;

angular position between the nozzles 31 of the feeding zone, i.e. of the inlet, into the micronization chamber 30, by means of the carrier gas G2, of the powdered material P to be micronized.

For the sake of clarity some of the sectional modules of the modular mill 10, in turn corresponding to the dimensional parameters listed previously, are shown separately one from the other in Fig. 3, divided into the sections (a)-(l).

Moreover, as integration of Fig. 3, Fig. 4, divided into sections (a)-(l), shows specifically these dimensional parameters and the corresponding modules in the context and in combination with the other parts and the other modules of the modular mill 10, of which they constitute essential parts, as already underlined several times, in order to clarify the features and the function of these dimensional parameters and therefore their relevance within the process of micronization of the powdered material P.

More particularly:

Fig. 4 - sect (a) is a sectioned view of the modular and instrumented mill 10 which shows the height H and the diameter D of the micronization chamber 30;

Fig. 4 - sect (b) shows the fitting radius Rl and the fitting radius R2 between the side annular wall 30a and respectively the flat lower wall 30b and the flat upper wall 30c of the micronization chamber 30;

Fig. 4 - sect (c) shows the fitting radius R3 between the flat upper wall 30c of the micronization chamber 30 and the upper immersion tube 33, and the fitting radius R4 between the flat lower wall 30b of the micronization chamber 30 and the lower immersion tube 32;

Fig. 4 - sect (d) shows the inner diameter Dl of the lower immersion tube 32;

Fig. 4 - sect (e) shows the outer diameter D2 of the upper immersion tube 33; - Fig. 4 - sect (f) shows the height Hl of the lower immersion tube 32;

Fig. 4 - sect (g) shows the depth H2 of the lower immersion tube 32;

Fig. 4 - sect (h) shows the height H3 of the upper immersion tube 33;

Fig. 4 - sect (i) shows the diameter d of the nozzles 31 which emit the gaseous jets G which create the spiral swirling flow V in the micronization chamber 30 and the slant a, with respect to the radial direction of the micronization chamber 30, of these nozzles 31 ;

Fig. 4 - sect (j) shows the position, defined by an angle g, with respect to the nozzles 31 of the inlet opening 37 of the powdered material P in the micronization chamber 30;

- Fig. 4 - sect (k) shows the vertical position of the nozzles 31 with respect to the inlet opening of the powdered material P in the micronization chamber 30;

Fig. 4 - sect. (1) shows the slant b, with respect to the radial direction of the micronization chamber 30, of the conduit for feeding of the powdered material P to the same micronization chamber 30.

It is also pointed out, as resulted from specific research performed by the

Applicant, that many of the dimensional parameters mentioned previously and illustrated, provided in order to be considered and appropriately evaluated in the use of the modular mill 10 in order to optimise the micronization of a powdered material, are overlooked and do not show a trace in technical literature, both patent and non-patent.

Therefore the present invention, as confirmation of its innovative features, takes into consideration and assigns its own and significant relevance to dimensional parameters and other quantities, overlooked by the prior art, in determining the features, the performances and the results of the micronization process. The sensors or measuring instruments, included and an essential part of the modular and instrumented mill 10, in turn comprise specifically one or more flow meters, a Pitot tube and/or other instruments again, apt to measure, during the tests and trials performed by means of the modular and instrumented mill 10, the following working process parameters:

mass flow rate, denoted by Qm’, of the powdered material P to be micronized, drawn by the gas G2 and fed to the micronization chamber 30 to be micronized; volume flow rate, denoted by Qv’, of the carrier gas G2, which transports and feeds the powdered material P to be micronized to the micronization chamber 30; - volume flow rate Qv” of the gas Gl under pressure fed to the outer annular chamber 34 to generate, by means of the nozzles 31 placed along the side annular wall 30a, the jets G of gas at high velocity which activate the gaseous vortex V in the micronization chamber 30, so as to cause the micronization of the powdered material P;

- mass flow rate, denoted by Qm”, of the micronized powdered material P’ at the outlet of the modular mill 10;

temperature and relative humidity of the carrier gas G2 which transports and feeds the powdered material P to be micronized to the micronization chamber 30;

temperature and relative humidity of the gas Gl, fed to the outer annular chamber 34 and to the nozzles 31 , which generates the jets G at high pressure which in turn determine the swirling flow V which causes the collision of the particles of the powdered material P in the micronization chamber 30 and therefore their micronization into finer particles;

the velocity, denoted by VEL, inside the micronization chamber 30, of the gas, ejected by the nozzles 31, which determines the gaseous swirling spiral flow V, towards the central zone of the micronization chamber 30, which causes the micronization of the powdered material P present therein; and

the velocity VEL, in various points and zones inside the micronization chamber 30, of the swirling spiral flow V which causes the micronization of the powdered material P.

For the sake of clarity, among the various sensors and measuring instruments, included in the instrumentation with which the modular mill 10 is provided and having the function of detecting and measuring the working process parameters mentioned previously, Figs. 5 A and 5B show two sensors or flow meters, both denoted by FL’, apt to measure the mass flow rate Qm” of the micronized powdered material P’ which exits, after micronization, from the modular mill of the invention, in which the sensor of Fig. 5A is of the type with electromagnetic field while the sensor of Fig. 5B operates on the basis of a radar signal.

Fig. 5C in turn shows the placing in the same modular mill 10 of this sensor FL’ apt to measure the mass flow rate Qm” of the micronized powdered material P’ produced by the modular mill 10.

Further, Fig. 5D shows a flow meter FL”, of the heat dispersion type, apt to be mounted in the modular mill 10 in order to control and measure both the volume flow rate

Qv” of the pressurised gas Gl which is fed to the outer annular chamber 34 of the modular mill 10 in order to generate the jets G of gas in the inner micronization chamber 30 and the volume flow rate Qv’ of the carrier gas G2 which transports and feeds the powdered material P, to be micronized, to the micronization chamber 30.

Fig. 5E in turn shows the placing, in the modular mill 10, of this flow meter FL” having the function of measuring these two flow rates Qv’ and Qv”.

Further, Figs. 6A and 6B are respectively a diagram of a typical Pitot tube, denoted by TP, having the function of detecting and measuring the pressure inside the modular and instrumented mill 10 of the invention in order to determine from this measurement the velocity VEL of the swirling flow V of the air inside it, and a view of the zone of coupling of this Pitot tube TP with an upper lid 35 of the same modular mill 10.

In use, the modular and instrumented mill 10 of the invention is initially assembled in a first configuration, for example such as that shown in Fig. 1, which is presumed, also on the basis of experience acquired and accumulated with experiments performed previously, to be suitable for micronizing, even if in a manner not completely optimal but in any case which can be improved, a certain and specific powdered material P of interest, using in the assembling of the modular mill 10 the various modules 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24 described previously, configured in fact to be varyingly assembled one with the other in order to compose the modular mill 10.

Then the modular mill 10, once assembled in this first configuration, is used to perform a first series of tests and trials, feeding it with the specific powdered material P of interest, in relation to which the parameters are to be optimised, apt to have a decisive influence on the features and on the results of its micronization, that is both the dimensional ones inherent in the configuration of the mill and the process ones inherent in the operation of micronization.

The results of these tests are then obtained, that is the grain size features and the distribution of the dimensions of the micronized particles of the micronized powdered material which is obtained and produced with these first tests.

If the results of these tests correspond to those expected and desired or at least are considered satisfactory, also taking account of the working process parameters detected by the measuring instrumentation which equips the modular mill 10, the configuration of the latter is not changed and is therefore considered as apt to define an optimal configuration of the modular mill in order to micronize the specific material of interest P.

If instead the results obtained with these first tests, that is the grain size features and the quality of the micronized powdered material produced with them do not correspond to those required and are therefore considered unsatisfactory, the various modules which make up the modular mill 10 are then modified, that is they are replaced with other similar modules or with the mounting of additional parts, such as spacers, shims and similar elements, as illustrated previously, so as to vary the dimensional parameters of the modular mill 10 and therefore compose it and assemble it in a new configuration, so as to be able to perform a new series of tests with the modular and instrumented mill 10 in this new configuration.

Subsequently the process continues progressively in this way, that is modifying the configuration of the modular mill, assembling in a different way the modules which compose it, performing a new series of tests with the modular mill assembled in the new configuration and evaluating the respective results, in terms of grain size features and quality of the micronized powdered material obtained with the tests, until these results are considered optimal or at least satisfactory, so as to define a corresponding optimal configuration of the mill apt to micronize in an optimal manner the powdered material P of interest.

In other words the configuration of the modular mill is changed and a series of micronization tests are performed after each modification of this configuration, until the results obtained, both in terms of quality and grain size features of the powdered material produced as part of these tests and of correspondence to other factors and features, are considered optimal or at least satisfactory, so as to define a corresponding optimal configuration of the modular mill, that is a configuration apt to micronize in an optimal manner the specific powdered material of interest P.

For reasons of clarity Fig. 8C shows an example of a distribution, denoted by DIS, of the dimensions of the micronized particles and which is obtained, measured and examined as part of these tests which are performed, with the modular and instrumented mill of the invention, in order to establish whether the micronization of the powdered material has reached or otherwise an optimal or at least satisfactory level and such as to fulfil the requisites demanded.

Further, Fig. 2A shows, by way of example, a possible second configuration, denoted in general by 110, wherein for the sake of clarity the corresponding parts which can be referred to the first configuration 10 are denoted by reference numerals incremented by 100, in which second configuration the modular and instrumented mill of the invention can be assembled and composed by combining differently the modules which make up and define the first configuration 10, and/or replacing them with others and/or adding other further modules, as a function of the data and results obtained with the tests and trials performed, in order to optimise both the dimensional parameters of the modular and instrumented mill and those inherent in the process of micronization and the features and final quality of the micronized material.

Furthermore, for the sake of completeness, further embodiments and configurations of the modular and instrumented mill are shown in Figs. 2B and 2C, in which the respective numerical references, since being clear from what has been described, have not been indicated for reasons of simplicity.

In particular, Fig. 2B shows the modular and instrumented mill in which the micronization chamber has a curved fitting configuration between the respective upper and lower flat walls, and the lateral and central cylindrical walls.

Instead, Fig. 2C shows the modular and instrumented mill with the respective micronization chamber which does not have a curved fitting configuration between its walls.

It is also clear that by means of these tests, performed with the modular mill of the invention and aimed at optimising the parameters of the micronization operation, useful and precious information is obtained which allows designing and dimensioning in an optimal manner, that is apt to meet the requirements demanded in terms of features and quality of the micronization of a specific powdered material of interest, of a spiral jet mill intended to be used in an actual industrial production.

Method and sequence of assembly of the modular and instrumented mill of the invention

For more complete information and as integration of the description of the structure which can be varyingly assembled and composed of the modular and instrumented mill 10 of the invention herein below an illustration will be given, referring to Fig. 9, divided into sections (a)-(n), to be considered clear and explanatory in themselves without the need to indicate the reference numerals of the various parts of the modular mill, the methods and the sequence of mounting in order to assemble it and compose it in a generic configuration, among the numerous possible configurations, to be used for performing tests and trials aimed at optimising the micronization process, in which the modular and instrumented mill of the invention can be mounted and composed.

In detail, a first phase of this sequence of assembly, corresponding to Fig. 9 - sect

(a), provides for the preparation of a first assembly composed of an upper lid of the modular mill, a respective wear disk, provided in order to face directly onto the interior of the micronization chamber and therefore to receive the impact of the particles of the powdered material to be micronized, and a corresponding seal O-ring.

More specifically Fig. 9 - sect (a) refers to a configuration of the modular mill, in turn corresponding as specified previously to that of the model MC150 spiral jet mill produced by the Applicant Micro-Macinazione, with height of the micronization chamber of 35 mm.

Fig. 9 - sect (b) refers instead to a configuration of the modular mill with height of the micronization chamber of 25 mm, wherein before the wear disk a disk is also mounted which acts as 5 mm shim.

In a subsequent phase of this sequence, as shown in Fig. 9 - sect (c), a closure element is screwed into a threading formed in the upper lid of the modular mill, so as to close this pack closure element on a step formed in the wear disk, with the interposition of a seal O-ring;

Then, as shown in Fig. 9 - sect (d), an outer body of the modular mill is prepared with a respective wear disk and appropriate shims, and it is composed and coupled with the lower immersion tube with the interposition of an O-ring.

In this case too, in the version of the mill with height of the micronization chamber of 25 mm, a 5 mm spacer is positioned.

Separately, as shown in Fig. 9 - sect (e), a closure element of the lower immersion tube is prepared, composing it with appropriate shims and seal O-ring.

Then, as shown in Fig. 9 - sect (f), this closure assembly is assembled and coupled with the outer body of the modular mill so as to close the lower immersion tube.

It is pointed out that, even if the spacers and the shims used to assemble the modular mill in its various configurations are coupled with a certain play with the body of the mill, the seal O-rings interposed between these parts can at times impede the manual extraction of these spacers.

For this reason three holes have been provided on the base of the modular mill, as shown in Fig. 9 - sect (g), for the insertion of an extractor to remove the various spacers and shims.

Fig. 9 - sect (h) shows in turn how the nozzles for the emission of the high- velocity gas jets in the inner micronization chamber are set up, with the respective seal elements, before their insertion in the inner separation ring which separates the two chambers of the modular mill.

Further on, as shown in Fig. 9 - sect (i), the nozzles, in the form of inserts, are positioned, centred and attached with appropriate pins, in respective seats formed in the inner separation ring.

Then, referring to Fig. 9 - sect (j), the inner separation ring is positioned in its housing inside the outer body of the modular mill.

In this respect it is specified that in the case of the micronization chamber with height of 35 mm it is necessary to insert 5 mm shims between the inner ring and the wear disks.

The subsequent phase of assembly consists, as shown in Fig. 9 - sect (k), in positioning and coupling correctly the Venturi tube and the respective O-ring with a tightening clamp or clamp ferrule, placed along the feed tube which feeds to the inner micronization chamber the carrier gas which transports the powdered material, and in the complete mounting of the assembly for feeding the powdered material to be micronized.

Further on, as shown in Fig. 9 - sect. (1), the two halves of the mill are joined and then the whole is closed with a clamp type closure, for example measuring 10 inches.

Then, as shown in Fig. 9 - sect (m), the upper immersion tube is mounted. In this respect it is pointed out that the coupling of this element with the other parts of the modular mill is with play, given that the radial seal element ensures in any case its seal and attachment.

In any case, for reasons of safety, on the 2 inch upper clamp fastening a closure gasket, type DN 40, is used, which has a smaller span.

In this way, once the modular mill has been closed, the gasket prevents the upper immersion tube from being able to move from its correct position.

Finally Fig. 9 - sect (n) shows how, in the version of the modular mill with height of the micronization chamber of 25 mm, it is necessary to position, before the upper immersion tube, a 5 mm spacer.

Further, for the sake of clarity and as integration of Fig. 9, Fig. 9A, divided into sections (a)-(f), shows some possible ways and examples of change, in particular using modules and elements constituted by shims, of the configuration and relevant dimensions of the modular and instrumented mill of the invention in order to optimise the working parameters thereof.

For example Fig. 9A - sect (a)-(b) shows how it is possible to change, using appropriate shims, the height H of the micronization chamber 30, so as to change from a configuration of the modular mill with a certain height of the micronization chamber to another configuration of the same modular mill exhibiting a different height of the micronization chamber.

Fig. 9A - sect (c)-(f) in turn shows how it is possible to change, again in this case using shims, the configuration of the lower immersion tube in relation to the other parts of the modular mill.

Finally, to sum up what has been described previously, the working block diagram of Fig. 9B illustrates the use of the modular mill of the invention to assemble it and compose it in a plurality of test conditions and working configurations, in order to perform a series of tests and experiments with the modular mill in these different working configurations, in order to succeed in defining, analysing the effective results and data obtained in this way, in particular concerning the features and the quality of the micronized powdered material produced with these tests, an optimal configuration of the same modular mill apt to optimise the features of the micronized powdered material.

It is therefore clear from what has been described and illustrated that the modular and instrumented mill of the invention reaches the objects set in full.

More precisely, the modular and instrumented mill, thanks to the modular structure and easy interchangeability and possible composition of the single modules whereof it is composed and to the special measurement instrumentation with which it is equipped, allows the obtaining, testing with this special instrumentation different configurations of the same modular and instrumented mill in turn obtained by assembling and replacing in various ways the respective modules, of useful data and precious information in order to optimise separately the working factors and parameters which are at the basis and influence the results of the operation of micronization, and the typical dimensional ones, such as for example the height of the micronization chamber, the number and the arrangement of the nozzles and the configuration of the lower immersion tube, and the typically process ones, such as for example the pressure of the gas which feeds the gaseous jets which generate the swirling flow so as to cause the micronization of the powdered material, the flow rate of the carrier gas which transports and feeds the powdered material to be micronized to the micronization chamber, the time of dwell in the mill of the micronized powdered material and other parameters again, in order to improve and optimise the quality and the fineness of the micronized powdered material.

Moreover the information and the data obtained from the tests performed with this modular and instrumented mill of the invention allow dimensioning and optimising of the configuration of the relevant zones and parts, such as the micronization chamber, the nozzles, the immersion tubes and other parts further, of an industrial spiral mill, that is provided in order to be used in large-scale production to micronize a specific powdered material, in which this industrial spiral mill reproduces the optimal dimensions and the configuration of the instrumented and modular mill as resulting from the tests and trials performed with the latter in order to micronize the specific powdered material.

Experiments and tests performed with a prototype of the modular and instrumented mill of the invention

A prototype of the modular and instrumented mill of the invention was produced and the subject of thorough and extensive experiments in order to check the features and the performances thereof.

The numerous tests and trials performed with this prototype have fully confirmed the innovative features and the advantages of this modular and instrumented mill.

More particularly the experiments performed have confirmed how the modular and instrumented mill of the invention allows, through a series of tests performed in a rapid and efficient manner and at a low cost, the optimising separately one from the other of the main and certainly the most important working parameters which determine and are the basis of an optimal micronization, performed using a spiral jet mill with swirling spiral flow, of a specific material or powdered substance of interest.

The experiments and the tests performed with the modular and instrumented mill of the invention, aimed at optimising the working parameters which determine the results of the micronization operation, have also confirmed how these tests allow the obtaining of relevant information and data which can be advantageously transferred and used in the field of actual industrial production of a specific powdered material of interest, for example in order to design a spiral jet mill, exhibiting an optimal configuration, intended for production at industrial level, i.e. on large scale, of a certain micronized powdered material of interest.

In the experiments performed with the prototype of the modular and instrumented mill of the invention various and different types of powdered materials to be micronized were used, of different grain sizes and features, in order to optimise the working parameters which determine the features and the quality of the micronized powdered material which is obtained from the micronization of these various and different materials and in particular lactose was used as being powdered material which has such features and properties as to allow effective simulation of the conditions and the results of the micronization of a vast range of powdered compounds and materials, in particular in use in the pharmaceutical field.

Moreover the development of this modular and instrumented mill and the respective experiments have allowed further analysis of the influence and the relevance of the working parameters and factors which are at the basis of the functioning of the jet micronization mills with spiral swirling flow.

Again the data obtained by the experiments performed with the modular and instrumented mill of the invention, appropriately analysed with the method and the algorithms of the so-called CFD, i.e. computational fluid dynamics, have allowed further analysis, understanding and clarification of the fluid dynamic phenomena which govern and condition the micronization of the powdered material inside the mill due to the spiral swirling flow.

More particularly this computational fluid dynamics CFD was found to be a fundamental and effective instrument for simulating and evaluating and therefore optimising the various working dimensional and process parameters, illustrated previously, which determine the end features and the grain size distribution of the micronized powdered material.

The measurements performed during the tests and trials with the instruments which equip the modular mill have also allowed experimental ascertaining of the correctness of the simulations performed with CFD and therefore a better understanding of the dynamics which governs the micronization so as to obtain useful information and data in order to optimise it.

By way of example Fig. 7 shows the points and the zones in which the velocity of the swirling flow of the air was measured, inside the modular mill and by means of a Pitot tube, and the speed vectors which were obtained with these measurements.

Further, Figs. 8A and 8B show two examples of simulation respectively of the distribution of the pressure and of the speed of the swirling flow of air in the modular and instrumented mill of the invention, which were performed using CFD (computational fluid dynamics) in order to optimise the working parameters of the micronization operation.

As clearly emerged from the experimentation carried out, the modular and instrumented mill of the invention proved to be an effective tool for the study, in a very efficacious and structured way, of the micronization process through the so-called DOE methodology (from Design Of Experiments), i.e. the planning of experiments, which methodology allows, through a limited number of experiments, to obtain relevant information not exclusively related to the influence of individual variable parameters but also to their correlation.

Finally, for a more complete information concerning the data and the results obtained with the experimentation that has been performed on the modular and instrumented mill of the invention, there are indicated here below some technical data, dimensional and operative, related to the model mill MC 150, whose optimization was precisely one of the aims of the development of this modular and instrumented mill and its experimentation, as already underlined:

- gas consumption at 7 bar: 1.8 m3/min

- mass flow of the powders: 1 ÷ 1.5 Kg/h

- initial granulometry: Max 1500 pm

- final granulometry: 0,5 ÷ 10 pm

- diameter of the micronization chamber: 150 mm

- mill sizes (F external diameter x height): 220 x 70 mm

- weight: ~ 9 Kg

Furthermore, the following tables show the ranges of variability within which, using in particular the DOE methodology, the salient parameters of the modular and instrumented mill were varied during the experimentation in order to define, study and optimize the micronization process.

Of course without prejudice to the basic concept of the present invention, it is also clear that changes and improvements may be made to the modular and instrumented spiral mill, as described heretofore, without thereby departing from the scope of the same invention.

Claims

1. A modular and instrumented spiral mill (10; 110) for the micronization of a powdered material (P), usable for performing tests and trials aimed at defining, studying and optimising the working parameters and therefore improving the efficiency and the performances of the micronization of the powdered material (P), comprising:

a plurality of modular elements or modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113, 114, 115), defining the configuration and the dimensions (D, H, d, Dl, Hl, H2, D2, H3, H4) of zones and parts (30, 31, 32, 33) of the modular and instrumented mill (10; 110); and

one or more sensors or measuring instruments (FL’, FL”, TP) placed in said parts or zones of the modular and instrumented mill (10; 110) in order to measure the working parameters of the same modular and instrumented mill during its use and functioning to micronize the powdered material (P);

wherein said modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112,

113) are apt to be varyingly assembled and/or composed and/or replaced one with the other in order to compose and form the modular and instrumented mill in a plurality of different working configurations (10; 110), so as to allow both the performing by means of the same modular and instrumented mill (10; 110) of a series of tests and trials of micronization in corresponding different working conditions and with different powdered materials, and the measuring, by means of said one or more sensors or measuring instruments (FL’, FL”, TP) included in the modular and instrumented mill (10; 110), of the effective working process parameters (QnT, Qv’, Qm”, Qv”, VEL) of the tests and trials of micronization that are performed with the modular and instrumented mill (10; HO), in order to optimise the quality and the features (DIS) of the micronized powdered material (P’).

2. Modular and instrumented spiral mill (10; 110) according to claim 1, wherein said modular elements or modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113, 114, 115) are selected among the various component parts of the modular and instrumented mill (10; 110) in that defining the configuration and the dimensions (D, H, d, Dl, Hl, H2, D2, H3, H4) of essential zones and parts (30, 31, 32, 33) of the same modular and instrumented mill (10; 110), that is of parts having a relevant and essential function in determining the features, the performances, the quality and in general the results (DIS) of the micronization process performed with the modular and instrumented mill (10; 110).

3. Modular and instrumented spiral mill (10; 110) according to claim 1 or 2, wherein said modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113, 114, 115) are provided to be assembled and/or composed and/or replaced one with the other in order to compose and form the modular and instrumented mill in said different working configurations (10; 110), taking account of the values of the working process parameters measured by said one or more sensors or measuring instruments and examining the features and the grain size distribution (DIS) of the micronized material (P’) obtained with said tests and trials, so as to succeed, through these same tests and trials performed with the modular and instrumented mill in said different working configurations, in composing and defining an optimal configuration (10; 110) of the modular and instrumented mill apt to optimise the micronization of a specific powdered material of interest (P).

4. Modular and instrumented spiral mill (10; 110) according to any one of the preceding claims, wherein the configuration and the dimensions of said essential parts and zones (30, 31, 32, 33) defined by and corresponding to said modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113, 114, 115) which can be composed and assembled one with the other, comprise:

- the general form or configuration of a micronization chamber (30), provided to receive the powdered material (P) to be micronized and in which the powdered material is micronized;

more specifically the height (H) and the diameter of the micronization chamber (30) and the fitting radii (Rl, R2) between an annular side wall (30a) of said micronization chamber (30) and respectively a lower surface (30b) and an upper surface (30c), more particularly both flat, of the same micronization chamber (30); the number, the orientation (a) and the diameter (d) of a plurality of nozzles (31), placed along said annular side wall (30a) of the micronization chamber (30), apt to eject into the latter a corresponding plurality of jets (G) of air or of another gas, pressurised, so as to determine a spiral and swirling gaseous flow (S), converging towards a central zone of the micronization chamber (30), apt to cause the micronization of the powdered material (P);

- the dimensions, such as the inner diameter (Dl), the height (Hl) and the depth

(H2) of a lower immersion tube (32) apt to receive from the micronization chamber (30) the micronized powdered material (P’), and to discharge or otherwise a portion thereof downwards in the direction of a recuperator;

the dimensions, such as the outer diameter (D2), the height (H3) of an upper immersion tube (33) apt to receive from said immersion tube (32) the micronized powdered material (P’) and to convey it upwards in the direction of a separator; the fitting radii (R3, R4) respectively between the lower immersion tube (32) and a lower wall (30b) of the micronization chamber (30) and between the upper immersion tube (33) and an upper wall (30c) of the micronization chamber (30), and

the inclination and the angular position between two consecutive nozzles (31) of an entry of the powdered material (P) into the micronization chamber (30).

5. Modular and instrumented spiral mill (10, 110) according to any one of the preceding claims, wherein said one or more sensors or measuring instruments, included in the modular and instrumented mill (10; 110), in turn comprise more particularly one or more flow meters, a Pitot tube and/or other instruments again, apt to measure, during the tests and trials performed with the modular and instrumented mill (10; 110), the following working process parameters: mass flow rate (Qm’) of the powdered material (P) which is fed to a micronization chamber (30) of the modular and instrumented mill where the powdered material (P) is micronized;

volume flow rate (Qv’), of a carrier gas (G2), which transports and feeds the powdered material (P) to be micronized to said micronization chamber (30);

volume flow rate (Qv”) of a gas (Gl) under pressure which feeds a plurality of gaseous jets (G) such as to generate a swirling flow in said micronization chamber (30) and therefore cause the micronization of the powdered material (P);

mass flow rate (Qm”) of the micronized powdered material (P’) which is produced and exits from the modular and instrumented mill;

temperature and relative humidity both of the pressurised gas (Gl) which feeds said gaseous jets (G) operating in the micronization chamber (30) and of the carrier gas (G2) which transports and feeds the powdered material (P) to be micronized to the micronization chamber (30);

- velocity (VEL) inside the micronization chamber (30), of the swirling spiral flow

(S) which causes the micronization of the powdered material (P).

6. Modular and instrumented spiral mill (10; 110) according to claim 5, exhibiting, in particular in the region of a respective upper lid, one or more points or holes suitable for allowing the coupling and the integration of the Pitot tube in the modular and instrumented spiral mill and therefore allow to measure through the same Pitot tube the velocity (VEL) of the swirling flow (V) of the air inside the modular and instrumented spiral mill.

7. Modular and instrumented spiral mill (10; 110) according to any one of the preceding claims, wherein said modular elements or modules, used to modify the configuration and the relevant dimensions of the modular and instrumented mill in order to modify and optimize its working parameters, consist of shims, spacers or similar elements, in particular suitable to be coupled with the other parts of the mill with O-ring sealing rings.

8. Modular and instrumented spiral mill (10; 110) according to any one of the preceding claims, wherein said modular elements or modules, when aimed at modifying and optimizing the configuration of a micronization chamber (30) of the modular and instrumented mill, comprise one or more elements, in particular in the form of wear discs, suitable for masking the walls (30a, 30b, 30c) of said micronization chamber (30) and therefore provided for receiving the collisions of the particles of the powdered material to be micronized.

9. Method for dimensioning in an optimal manner a spiral jet mill, in particular of the industrial type, for the micronization of a powdered material comprising the following steps:

providing a modular and instrumented spiral mill (10; 110) according to claim 1 or 2 or 3;

composing and assembling in various ways said modules (11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24; 111, 112, 113, 114, 115) so as to form different configurations of the modular and instrumented mill (10; 110);

performing a series of tests, with the modular and instrumented mill (10; 110) in said various configurations, to micronize a specific powdered material;

using and processing the data obtained, during the performing of said series of tests, by said one or more sensors or measuring instruments included in the modular and instrumented spiral mill (10; 110), and the corresponding information, in order to define and dimension the relevant zones and parts of an industrial spiral mill, in particular of the industrial type, similar and corresponding to said modular and instrument spiral mill used for the tests, intended to be used in production in order to micronize at industrial level said specific powdered material.

10. Method for dimensioning in an optimal manner a spiral jet mill for the micronization of powdered material according to claim 9, wherein the data detected with said tests are processed with the so-called computational or numerical (CFD) fluidynamics algorithms.