EP1979081A1

EP1979081A1 - Measurement, monitoring and control of directed product movements in fluidized bed or spouted bed systems and suitable systems

Info

Publication number: EP1979081A1
Application number: EP07702954A
Authority: EP
Inventors: Jochen A. Dressler; Manfred Struschka; Bernhard Luy
Original assignee: Glatt GmbH
Current assignee: Glatt GmbH
Priority date: 2006-02-03
Filing date: 2007-01-23
Publication date: 2008-10-15
Also published as: BRPI0707486A2; US20090011118A1; US8187663B2; CN101426568A; WO2007090515A1; JP2009525472A; DE102006005382A1

Abstract

A process is described for measuring, monitoring and/or controlling directed product movements of fluidized products in process systems (1) selected from fluidized bed and spouted bed systems during a spraying process for coating and/or granulation, which comprises, with the aid of one or more microwave sensor devices (8), injecting microwave radiation without contact into one or more product streams, receiving the microwave radiation reflected by the particles of the particular product stream and, on the basis of the microwave radiation received, forming and transmitting a measurement signal for the characterization of the product stream, the corresponding use of microwave sensor devices (8) and correspondingly equipped apparatus (1).

Description

Measurement, monitoring and control of directed product movements in vortex or jet bed plants and suitable facilities

The invention relates to a method for measuring, monitoring and / or regulating directed product movements in vortex or spouted bed systems, the use of suitable measuring devices for this purpose and with these measuring instruments equipped vortex and spouted bed systems (= fluidized beds or spouted bed plants).

Widely used in the pharmaceutical industry, but also in the food, feed and fine chemical industries, involves the coating of particulate matter in the fluidized bed or spouted bed by suspensions, solutions, powders or melts. In this case, a certain amount of these particles by a process gas stream in a vortex or spout system (hereinafter also referred to as process plant) is set in motion and entrained with the gas stream, preferably air as gas, but possibly also nitrogen or other suitable gases or gas mixtures Find use. Down the process space is delimited within the process plant by one or more distributor plates, which are designed as a gas distributor and allow the process gas flow evenly and / or divided into different zones. Such distributor plates (for example designed as a sieve bottom plate) prevent their design from falling through the particles down into the inflow region of the process gas. If one or more spray nozzles are located in the region of this inflow base, by means of which the particles are sprayed with the spray medium and granulated or preferably coated, these are generally referred to as "bottom spray." Such spray nozzles are commercially available in various designs and are described in particular as US Pat One or preferably used as two- or three-fluid nozzles.To obtain particularly uniform coatings on the particles, the particles in the

DC sprayed and dry almost completely during the fluidization and flight phase. In order to separate the particles which have been stirred up in the spray jet from the falling, drying particles, certain installations or guide devices are installed in the process chamber. Such installations are described, for example, in DaIe E. Wurster et. al. (U.S. Patent 3,191,827 and U.S. Patent 3,241,520). By additional Inserts in the process chamber can further improve the quality of the product. EP 0570546 describes for this purpose a possibility to shield the spray nozzle so as to bring the particles to be sprayed into contact only in the region of a well-developed spray jet. This improvement can additionally achieve a higher spray rate. For heavier and particularly sensitive particles - for example tablets - internals according to EP 1232003 were developed to protect the product. As a result, the product flow is better steered and protected the product from abrasion and mechanical stress. Several corresponding internals enable multi-chamber or continuous systems, such as shown in US 3,241,520. All of the aforementioned systems thus work according to the so-called "Wurster principle".

Corresponding product flows and built-in components can also be found in jet-bed systems operating according to the "bottom-spray" principle (which can likewise be configured in one or more stages), see also DE 103 22 062 A1 and EP 1 325 775. Spraying there also takes place Nozzles in the direction of the main product flow, which is directed against the force of gravity, so that both the Wurster principle and after the spouted bed method, so DC method or the DC principle can be realized.

In all of the process plants that operate on the Wurster principle, today usually straight, preferably cylindrical in cross-section risers - so-called

Wurster tubes - used whose distance to the distributor plate is variable and ideally can be adjusted from the outside. The advantage of this coating method according to the DC principle is a particularly uniform and homogeneous application of the coating material to the particles submitted.

Alternatively to or in addition to the spray nozzle arrangement according to the bottom spray method, however, the spray nozzles can also be attached laterally to the process vessel of the vortex or spouted plant or also to certain internals in vortex or spouted bed plants, wherein they are approximately perpendicular to and / or also preferably here can spray in the direction of the product stream. Corresponding conditions can be found in spouted bed apparatuses.

The spray rate with which the coating material is applied to the particles to be coated can either be kept constant over the entire course of the process or can also be adapted during the course of the process. It is important in this

Context that the particles are distributed as evenly as possible and with as possible at a constant rate through the spray jet. If at a given constant spray rate more particles are passed through the spray, many particles are no longer sprayed when passing through the spray or no longer sufficient and can be damaged by abrasion or other mechanical stress. Particle breakage and spalling of already applied coating layers can occur. If fewer particles are passed through the spray jet at a given spray rate, excess spray drops can not be trapped by particles. The drops dry off in the process gas stream and accumulate as fine dust. In addition, the excess droplets can settle on the edge regions of the riser and form deposits there. Such deposits hinder uniform fluidization (more generally, even product flow) and can lead to poor coating results. Particulate matter, in turn, can interfere with the formation of a smooth, uniform surface of the coated particles. For a reproducible and uniform coating process, it is therefore an important prerequisite to have a constant product flow (for example in the riser pipe of a

Fluidized bed plant according to the Wurster principle). If the product flow stops due to blockages in the product area or in the area of the spray nozzle, the quality of the product can be seriously endangered. Especially when using larger process plants with several risers or corresponding internals, a blockage or an irregularity is often not noticed in time enough to intervene.

By appropriate adjustments of the process conditions and process parameters, the bottom spray method (or equivalent methods with side nozzles) can also be used for the granulation of particles. Here you will find analogous difficulties as in the previous paragraph. Here as well as there is to pay attention to a correspondingly good quality of fluidization in order to avoid these problems and process risks.

In granulation and coating processes, the term "particles" encompasses all particulate materials or objects that can be fluidized in the fluidized or jet layer (preferred variants are defined below), which can be granulated or coated in fluidized bed systems.

So far, the quality of the fluidization in the fluidized or jet layer through viewing window, mounted in the coating container, by camera systems or through the Measurement of the differential pressure at the distributor plate (eg a sieve bottom plate) can be assessed.

Viewports have the disadvantage that they allow observation of the movement of the returning particles only from the outside. The observation through viewing windows is only possible with the aid of strong light sources, which depending on the product may also mean a thermal load on the product particles. Observation by camera systems requires, due to the high particle velocity, a sufficiently fast camera system so that the movements of the fluidized particles remain distinguishable. Camera systems as well as viewing windows require a light source. Dust deposits can contaminate and tarnish camera lenses. The view is so limited. Only expensive flushing systems with flushing gases such as compressed air can reduce the formation of deposits. All the optical control possibilities described above result in only unsatisfactory qualitative detection of the fluidization behavior (in which, in particular, the degree of fluidization, the density of the material flow and the speed of the material flow enter into) of particles in the riser. A quantitative statement on the fluidization behavior is not possible.

The measurement of the differential pressure is highly dependent on the air distribution and the flow resistance of the inflow base. Particularly in coating processes with more than one riser, the measurement of the differential pressure is limited meaningful.

In order to identify and monitor all the aforementioned problems and process risks, and if necessary to intervene to regulate, the direct measurement of the product flow in the riser is necessary. A direct measurement is possible for example by capacitive measurement methods or by measuring the electrical resistance in the riser. However, these methods are greatly influenced by influences of product moisture or material property. Often the dielectric constant of the product also changes during the coating process, so that the capacitive measurements take place under changing conditions. Also, the difference in capacitance change in a filled riser compared to an unfilled riser is very small even under ideal conditions. A reliable measurement or evaluation of the signals is not possible. Interference signals, for example due to the influence of the test leads, further restrict the applicability of this method. When measuring the electrical resistance, dust deposits or contamination occurring during the process can be added to the measuring electrodes Lead to incorrect measurements. The resistance measurement can also be impaired by the purified and deionized water used, for example, in pharmaceutical production.

WO 98/44341 A1 discloses a method for monitoring and / or controlling and regulating a granulation, agglomeration, instantization, coating and drying process in a fluidized bed or a moving bed by determining the product moisture and an apparatus for carrying out the same Known method. The damping of high-frequency waves smaller than 100 MHz or microwaves by means of moisture present in a fluidized bed is determined by means of a sensor (designed as a planar sensor) which is flush with the inside of the outer wall (designed as a planar sensor). The measurement signal is described as essentially only dependent on the moisture content and the product temperature. The relevant resonant frequency is described as referring to the entire fluidized bed, not individual particles. Electronic measurement signal and "product moisture measured offline" are correlated for calibration.

In WO 98/44341 A1, the total product moisture is measured - the fluidization must still be determined by other, as the above, methods with all their possible weaknesses.

In DE 195 045 44 the loading and speed of coal dust through pipes for controlling the firing of a boiler (especially on adjustment of the supply amount of air for combustion) is described in a coal power plant by means of microwaves. A usefulness of microwave technology in conditions of variable moisture content during spraying is not suggested or described. The purpose is there the regulation of the downstream combustion, not regulation within the space of the microwave measurement.

It is therefore an object to provide new methods and devices that make it possible to measure, monitor or regulate directed product movements in vortex or spouted beds, which can avoid the mentioned disadvantages of other measurement techniques described above and a direct Measurement of the fluidization behavior in a qualitative and / or quantitative manner and a direct qualitative and / or quantitative detection of product flow interruptions during

Spray coating and / or granulation processes in the fluidized bed or spouted bed permit, and / or a device, monitoring or control and / or an up- or down-scaling of a given vortex or spout system to another possible with different dimensions of the given facility or at least facilitate.

The present invention enables the solution of the problems presented and for the first time a direct measurement, monitoring and / or regulation of the fluidization behavior, both qualitatively and quantitatively. In the case of coating installations with several installations, such as risers (= sausage pipes), moreover, for the first time for each corresponding compartment, e.g. for each riser, its own measurement and determination and / or a

Monitoring the fluidization done.

Instead of a riser, any differently configured process chamber of a fluidized bed system can be equipped with this measuring method, provided that the product flow in this area has a directed movement with a predetermined direction of movement. Qualitative and quantitative statements about the course of the process and control and regulating tasks are then also possible according to the invention in these process chambers. For example, variants with horizontal circulating product flow are described below.

In a first embodiment, the invention relates to a method for measuring, monitoring and / or regulating (in particular for monitoring and / or regulating) product movements of fluidized products in process plants selected from vortex and spouted bed installations during a coating and / or granulation spraying process characterized in that it comprises that microwave radiation is irradiated contactlessly onto one or more product streams with the aid of one or more microwave sensor devices, microwave radiation reflected by the particles of the respective product stream (= the respective product movement) is received, and a measurement signal for characterizing the microwave radiation is received Product stream is formed and output. Preferably, in this case the coupling of the microwave radiation is carried out in the outer region of the respective product stream, in particular in the range of one or more guide devices. In this case, outside is in particular a region which adjoins directly to the outer edge of the product stream, above all an area within a wall of the process space or in particular a guide device. In a preferred embodiment of the invention, the or the microwave sensor devices have combined transmitting and receiving units for microwaves, in particular a transmitting and receiving unit per measuring point, in combination, which allows a particularly simple installation and good coordination. The coupling of the microwave radiation can be carried out directly from the (if necessary correspondingly covered) transmitting unit into the desired measuring range (= at the point where the material flow to be measured is located, preferably in the region of the outer edge thereof); Preferably, a waveguide (in particular tubular, eg in the form of approximately or actually round or polygonal tubes) are preferably used for this purpose or in particular per transmitting unit, which may consist of customary for this purpose ladders, especially metals or alloys, one (proximal) end respectively several or preferably a transmitting and receiving units (Mikrowellensensorvor- direction (s)), while the other (distal, lying on the side of the measured product flow) end is closed by a microwave radiation sufficiently permeable cover, for example of a plastic material , This makes it possible to prevent an inflow of material from the product flow and so non-contact (which is mainly "without removal of material from the product flow and only the interaction of electromagnetic waves with the material to be measured" is understood, in particular touches with external parts of the microwave sensor device not excluded are) to measure.

As a microwave sensor device, which in particular at least one transmitting and receiving unit for microwave radiation and, if desired, also include a transmitter, in particular commercially available devices can be used, as described for example in US 6037783 or EP 0808454. A material used for the examples shown below model, for example, the sensor SolidFlow ^® from SWR engineering Messtechnik GmbH, D-79424 Auggen, Germany, with the suitable for processing electronic FME. An adaptation to fluidized bed or spouted systems can be achieved for example by suitable dimensioning of the waveguide.

Preferably, the coupling of the microwave radiation is carried out in the product flow to be examined perpendicular or approximately perpendicular to the main direction of the product stream, but it can also be made at any angle. In particular, the coupling of the microwave radiation in the range of one or more guide devices (Leiteinbauten), which are provided within the outer wall of the container of the vortex or spout system, made the (supported by the associated process gas flow) support the directed product flow (ie not on the outer wall but via lying within the outer wall further guide devices or in particular their walls or areas of the walls, which are not part of the outer wall), wherein preferably the coupling via one or more waveguide takes place and the one or more distal ends of the waveguide or the one or more microwave sensor devices are mounted in particular such that they have a (as mentioned, preferably within, ie in particular independent of the outer wall of the system or the coating container disposed within the same) wall of the one or more L. penetrate through it (ie, there are corresponding recesses provided, such as holes or slots, which preferably have arranged around the waveguide covering devices to seal the not filled by the waveguide region of the wall against the influx of process gas and particles sufficiently and thus allow an undisturbed product flow ) and its distal end, preferably approximately flush with the surface of the respective wall facing the product flow (ie without imparting appreciably in the space provided for the product flow, which allows a particularly trouble-free measurement), faces the product flow, while the proximal end is preferably on the non-product flow side facing the wall (s) of the guide (s) is provided, preferably also outside the outer wall of the system, so that in the latter case, the transmitting and receiving unit outside the outer wall of the vortex or spout layer plant is provided. Preferably, a waveguide per microwave sensor device may be provided, but embodiments of the invention are also in which a microwave sensor device alternately supply two or more waveguides with microwave radiation and the reflected microwave radiation can receive, for example by means of a multiplexer device, the alternating and separate connection one of several waveguides allows.

The method according to the invention is preferably carried out in such fluidized bed or jet bed systems in which the product flow to be measured, monitored and / or regulated flows against gravity, ie in particular substantially upward, in particular in fluidized bed systems with one or more Wurster tubes or further in spouted beds having one or more Conductors, each in the lower region with spray direction against the action of gravity (ie in particular substantially upward) or laterally with spray direction perpendicular and / or preferably parallel to the product stream one or more single or preferably more, such as two- or three-fluid nozzles for spraying liquids for coating (coating) and / or granulating particles forming the product stream. Particularly preferred is the application of the method for measuring, monitoring and / or regulating the substantially upwardly directed product stream in the bottom spray method (ie where the spray nozzle (s) are provided in the distributor plate area and spray substantially upwards). Particularly preferred as a process plant, in particular here, a Wurster plant with one or more sausage pipes as Leiteinrichtungen. In other areas than the product streams to be measured, for example, outside a Wurster tube or in another area, which is spaced from a guide, a reverse product flow may take place (from falling, previously spray-coated and / or granulated product particles, for example can be fed back to the product flow near the ground and thus ultimately perform a circular motion).

A very preferred embodiment of the invention relates to a method according to the invention, in which the product stream is measured, monitored and / or regulated within one or more sausage pipes within a fluidized bed plant operating on the Wurster principle (also referred to below as Wurster plant).

Alternatively, however, a (at least substantially) horizontally circulating product stream, which rotates about a vertical axis of the process plant, can also be subjected to the process according to the invention. The circulation may be excited and maintained, for example, by means of at least one appropriately shaped distributor plate, for example by suitably shaped slots or openings which at least partially impart to the process gas a component of motion parallel to the bottom, such as conidur plates, gill plates or gas distributor plates with overlapping segments or parts, between which columns allow a corresponding directed process gas flow. Examples can be found in EP 0 507 035, WO 97/23284, EP 0 370 167, WO 98/17380 or in particular DE 331 48 87 and US Pat. No. 4,591,324, which are preferably incorporated herein by reference. Advantageously, a corresponding process plant according to the invention or a corresponding method in addition to the at least one distributor plate also at least one (openable and closable at the appropriate time) lateral output. Due to this, product which can no longer be treated can be removed laterally due to the centrifugal force during the circular movement. Such a method according to the invention preferably includes that the removal (in particular automatically) is effected or performed and / or terminated upon entry or reaching of a specific property of the product stream or a corresponding resulting measurement signal of the microwave sensor device, for example automatically.

Product flow means (ideally largely fluidized) flow (= (at least essentially) directed product movement of fluidized products) of product to be coated and / or granulated by a process gas fed via one or more distributor plates (and in part also by the spray direction of single or multi-fluid nozzles for the coating and / or granulation), whereby under product particles of a finished and finished at the end of the intermediate or final product, such as pellets, coated (= coated) pellets, tablets, granules, capsules, Extrudates, crystals, powders or other particulate materials or correspondingly small objects can be understood. For example, the size of such product particles can be in the micrometer to millimeter range, such as from (about) 50 μm to (about) 25 mm or from (about) 200 μm to (about) 10 mm. This creates (in contrast to a true fluidized bed in the absence of baffles) a directed product movement - for example, along a guide on one side up, on the opposite side down. "Directed" (= essentially directed) means in particular that the net current of the particles has a certain (eg linear or circular) direction, whereby, for example due to fluidization, gravitation and turbulence, partial deviations may occur - the better the movement of the particles Individual particles corresponding to the net current, the clearer measurement signals can be obtained by means of the microwave device, and conversely, the clearer and more constant measurement signals are obtained, the smoother the product flow.

It is surprising that (unlike the state of the art to be expected), the measurement conditions can be easily adjusted so that the influence of moisture or the influence of the spraying process is low, in particular not (at least not only) the attenuation is evaluated, but the particle movement by measuring the particles reflected by the particles Microwave radiation, which is evaluated in terms of frequency and amplitude, preferably both parameters, so (at least) also taking into account the frequency change in reflection by the moving particles because of the Doppler effect.

Preferably, the evaluation is frequency-selective, so that it is ensured that only flowing particles are measured and, for example, stationary deposits or even a disturbing influence of a change in humidity are suppressed.

Thus, the corresponding microwave sensor device can work more or less like a particle counter, which makes it possible to determine a measurement signal for the amount of particles flowing per unit of time.

For forwarding and / or (whole or partial) evaluation of the measuring signals from the microwave transmitting or receiving units or the microwave sensor devices or preferably a (preferably each microwave sensor device individually assigned) associated evaluation is used, directly or via other components If, for example, for lack of integration of a digital output required, via an analog / digital converter and / or other modu Ie, such as resistors for voltage adjustment or the like, the formation and forwarding of a measuring signal formed in the course of measurement (for example, a current or voltage signal) to another Evaluation and / or control unit can cause, for example, to a suitably programmed computer (computer, eg PC), for example the display or tabular or graphical representation of a measurement signal or its evaluation or the system control allows, for example, via the transmitter.

The measurement or measurement signal acquisition can be carried out continuously, in pulses or at intervals, wherein different measurement times are possible for the pulses or interval measurements, for example advantageously relatively short measurement times, for example in the range from fractions of a second to a few minutes. For example, with uniform or likewise correspondingly interrupted microwave irradiation, this can be done by setting a filter time or sampling time, for example at an evaluation electronics, for example in the range from 0.2 to 200 seconds, in a possible advantageous variant from 1 to 30 Seconds, can lie. For the purposes of the present invention, (in particular the irradiated microwaves) are electromagnetic waves having frequencies of 300 MHz to 300 GHz, for example advantageously 1 to 100 GHz, for example at 24.125 GHz ± 100 MHz.

In a further preferred embodiment of the invention, the method according to the invention can also be used to transfer data (data downwards or upscaling), obtained by means of a fluidized bed or jet bed installation of certain dimensions, to installations with smaller or larger dimensions, preferably automatically by means of corresponding data Software and hardware.

"In process plants selected from vortex and jet bed plants" means, in particular, within the vortex or jet bed tank (ie, not in feeding tubes, for example).

In particular, the quality (eg with regard to degree of fluidization, size and / or speed of the particles in the product stream), in particular without calibration, in particular the uniformity of the product stream, and / or the quantity (eg with respect to the amount and / or the speed the particles in the product stream) of the fluidized product stream and / or in particular the fluidization are determined, compared with SoI I parameters and readjusted accordingly, automatically and / or manually. Even a calibration-free measurement allows statements regarding the quality of the product stream and is particularly preferred because of their simplicity. In particular, the "quality" or "quantity" does not refer to the product moisture as such, i. this is not self-characterized.

The invention also relates to the use of one or more microwave sensor devices, preferably each with a transmitting and receiving unit and a waveguide, in a method as described above and below.

A further embodiment of the invention relates to devices which are suitable or in particular configured for carrying out a method according to the invention, in particular vortex or jet layer systems which are provided with components mentioned above or below for the components used for the method. Preference is given here (A) an apparatus for performing a method as described above or below, which is a process plant for coating and / or granulation in the form of a fluidized bed or jet bed system with one or more spray nozzles (in particular a spray direction about (= direct or about) upwards and can be embodied as single-fluid or multi-fluid nozzles) and one or more guide devices and which has at least one microwave sensor device, characterized in that at least one wall (not belonging to its outer wall) located within the process system is one of the mentioned Leiteinrichtungen one of a planned directed product movement in the form of a

Product stream facing Einkoppelungsstelle for radiated from such a microwave sensor device microwave radiation and at least one intended product flow for a coupling point for reflected from particles of such a product stream microwave radiation.

(B) A device is preferred in particular according to the preceding paragraph, which is characterized in that at least one waveguide for microwaves is provided for coupling in the microwave radiation emitted by the microwave sensor device or devices which penetrates a wall of a guide device located within the process system which is provided at the distal end with a microwave permeable cover, and whose distal end is provided on a side of said wall facing a product flow approximately flush with the intended product flow facing surface of said wall, while the proximal end to which the Microwave sensor device is coupled, is provided on a side facing away from the intended product flow of said wall.

(C) Even more preferably, in particular, due to the clear construction, a device according to the above paragraph (B) is characterized by comprising two or more of said guiding means and including a microwave sensor device comprising two or more alternately switchable ones of said waveguides, each one of them leads to each one of the located within the device walls of the guide devices.

(D) Even more preferred is a device according to the preceding paragraph, characterized in that therein a central height adjustment mechanism is provided which it makes it possible to move the position of the guide devices up or down, in particular because it has a clear and compact structure.

(E) Even more preferably, a device according to paragraph (D) ₁ is characterized in that the central height adjustment mechanism is firmly connected to the microwave sensor device and the waveguides and via this with the walls of the guide means, so that a common height adjustment of all said components is possible ,

(F) Also more preferred is a device according to paragraph (B), characterized in that one or more guide devices are provided and each microwave sensor device comprises a transmitting and receiving unit for microwave radiation and each microwave sensor device one of said waveguide is provided. This also allows the separate measurement for each guide.

(G) Even more preferably, a device according to paragraph (F), characterized in that one or more height adjustment mechanisms are provided therein for the one or more guide devices. This allows e.g. an adjustment of the height of the baffles in favor of an improved product flow.

(H) Even more preferably, a device according to paragraph (F) or (G), characterized in that it is provided for the one or more guide means, a central height adjustment mechanism. This allows e.g. a very compact structure.

(I) Even more preferably, a device according to one of the paragraphs (F) to (H), characterized in that a microwave sensor device is provided with a waveguide for each guide.

(J) Particularly preferred is a device according to paragraph (I), characterized in that each microwave sensor device installed in the region of the central height adjustment mechanism of the guide (s) and preferably firmly connected thereto and thus together with one with it and one wall of one of the guide devices connected waveguide itself is height adjustable. Thus, a simple height adjustment can be achieved via a height adjustment mechanism and without the need of slots in the wall of the guide. (K) A likewise preferred device according to one of paragraphs (F) or (G) is characterized in that the one or more microwave sensor devices lie outside the outer wall of the process plant and in each case via waveguides which penetrate the outer wall and in each case one wall of a guide device, connected to the interior of the device. This allows eg good accessibility.

(L) More preferred is a device according to paragraph (K), which is characterized in that the outer wall and / or a wall per guide for carrying out the waveguide or a corresponding number of slots has, in the area around each waveguides are sealed by covering devices.

(M) Very preferably a device according to one of the paragraphs (H) to (L), characterized in that for each guide means a microwave sensor device is provided, each with a waveguide, so that e.g. each product stream can be measured individually.

(N) Also, a device according to any one of paragraphs (A) to (M) is very preferred, which is characterized in that it comprises the spray nozzles in the form of one or more single or multi-fluid nozzles in the region of an inflow floor.

(O) Very preferred is a device according to any one of paragraphs (A) to (N) for bottom spray methods.

(P) A device according to one of the paragraphs (A) to (O) is also very preferred, characterized in that it has one or more guide devices in the form of one or more sausage tubes, that is to say a fluidized bed system based on the Wurster principle ,

(Q) A device according to one of the paragraphs (A) to (P) is very particularly preferred, which has one or more microwave sensor devices and at least one evaluation, which is an evaluation of reflected by the particles of a product stream microwave radiation in frequency and amplitude, preferably frequency-selective , allows.

(R) A device according to one of paragraphs (A) to is also very particularly preferred (Q), characterized in that each microwave sensor device is connected via an evaluation electronics and / or or via further components with an evaluation and / or control unit.

The invention also relates to a process installation suitable for a method according to the invention or in particular equipped with at least one microwave device, in which at least one boundary selected from the outside wall, distributor plates and / or guide devices located within the process system comprises at least one intended product movement (7) Form of a product stream facing coupling point for radiated from such a microwave sensor device (8) microwave radiation and at least one intended product flow facing coupling point for reflected from particles of such a product stream microwave radiation (ie in particular the one or more input and output points not necessarily in the range of one or more Guide devices inside the process plant, but must be incorporated in the outer wall and / or in the distributor plate, but alternatively and / or supplementary can be introduced in the distributor plate), wherein apart from the position of the coupling and decoupling point otherwise the other features as in paragraph (A) or one or more of paragraphs (B) to (Q) are realized, wherein the process plant preferably for generating a essentially horizontal circular product flow (in particular by means of at least one as described above in the horizontal circulation process suitably designed inflow floor) is equipped, and in particular at least one lateral (open and closeable) output (for lateral product removal) may have. Preferably, at least one waveguide for microwaves, which penetrates at least one of said boundaries, which is provided at the distal end with a microwave-permeable cover, and whose distal end adjoins one at a time, is provided in a corresponding process installation for coupling the microwaves to the one or more microwave sensor devices the product flow side of the boundary (s) is provided, while the proximal end to which the microwave sensor device (s) is or is coupled is provided on a side of the boundary (s) sent to the intended product flow. Advantageously, such a device may have two or more of said limitations and include a microwave sensor device having two or more alternately connectable waveguides each leading to one of the boundaries located within the device (process plant). Alternatively, each one Microwave device having a transmitting and receiving unit for microwave radiation and each microwave sensor device of one of said waveguide may be provided. In a particularly preferred manner, in the case of the process plants mentioned above in this paragraph, the microwave device (s) may be outside the process plant and in each case connected to the interior of the device via waveguides which penetrate the outer wall of the process plant. Very particular preference is also given to the abovementioned process plants in which the spray nozzles are provided in the form of one or more one-component or multi-component nozzles in the region of an inflow base, in particular for bottom-spray methods. In addition, at least one evaluation unit may be provided in each case in the above process plants, which enables an evaluation of the microwave radiation reflected by the particles of a product stream with respect to frequency or frequency and amplitude, preferably frequency-selective, in particular taking into account the frequency change of the radiation reflected by particles within the product stream.

The invention also relates to a method mentioned above or below, which uses or is carried out in one of the said devices.

Preferred embodiments of the subject invention can also be found in the claims, in particular the subclaims, which are incorporated herein by reference. Preferred embodiments of the invention are also further obtained by replacing more general terms or particulars by more or less specific or preferred definitions (also in the claims), individually or in groups.

It shows as (possible preferred) examples of devices according to the invention or

Method or its measurement results:

Fig. 1: Schematic lateral cross section through an exemplary bottom-spray fluidized bed system with (as an example of a guide) Wursterrohr (ie a Wurster plant) and built-in microwave sensor device together with waveguide.

Fig. 2: Schematic cross section (from above) through an exemplary fluidized bed plant according to the bottom spray principle with (as an example of Leiteinrichtungen) three sausage pipes and a corresponding number of connected via waveguide, located outside of the fluidized bed container microwave sensor devices with central height adjustment for the Wursterrohre , Fig. 3: Schematic cross section (from above) through an exemplary

Fluidized bed plant according to the bottom-spray principle with (as an example of

Leiteinrichtungen) three sausage pipes and connected via waveguides with the Wursterrohren and associated with a central height adjustment, located within the fluidized bed container microwave sensor devices.

Fig. 4: Graphical representation of the measured data of an example of uneven fluidization at 40 mm compared to 50 mm distance between the distributor plate and Wursterrohr with good fluidization.

Fig. 5: Graphical representation of the measured data for an example of the influence of different amounts of process air on the fluidization behavior in a Wurster tube.

6: Exemplary graphical representation of the measurement data for a fluidization in a Wurster tube with different fill quantities of the product container. Determination of the minimum necessary product quantity.

The following examples illustrate the invention without limiting it, but may also illustrate preferred embodiments for methods according to the invention, devices according to the invention and uses according to the invention:

Example 1 Inventive Device for a Method According to the Invention

The structure of a possible measuring arrangement for a method according to the invention is described by way of example in accordance with FIG. 1 for a monotube Wurster coating process. A process plant 1, here exemplarily as (also preferred) fluidized bed plant according to the bottom spray principle shown (for example, it may be a fluidized bed plant type GPCG15 = smooth powder coater granulator, Glatt GmbH, Binzen, Germany, which also used in the following examples), has a coating container 2. This is at the bottom by a distributor plate 3, here exemplified as (also preferred) screen bottom plate running, which simultaneously prevents the product as falling through the sieve, delimited. A spray nozzle 4 with optional nozzle collar 5 ensures the application of the coating material to the submitted particles, which with the aid of the inflow over the inflow 3 process gas and the guide 6 (exemplified as (also preferred) riser or Wursterrohr) directed product movement. 7 (Product stream). Microwave radiation is coupled by a microwave sensor device 8 (with (preferably one each) transmitting and receiving unit for microwaves and possibly evaluation electronics) directly or preferably via a waveguide 9 in the guide 6. As appropriate Positions have the upper, the middle or the lower portion of the guide 6 proven, preferably about the middle of the guide 6 can be used as the optimum position. Preferably, but not necessarily, in the located within the process plant wall 10 of the guide 6 (at least) a slot 11 is integrated, by a height adjustment of the guide 6 with rigid mounting of the transmitting and receiving unit 8 and optionally the waveguide 9 with a proximal End 12 and a distal, product flow-facing end 13 (which should be closed with a microwave transparent material) is possible (for example, when using a Wursterrohrs with a diameter of 22.86 cm and a height of 60 cm and a thickness of 3 mm as used in the examples below, a slot 11 in the range of 6.5 to 12.5 cm below the upper edge of a Wurster tube and / or be provided from 23.5 to 29.5 cm below this upper edge). The slot 11 (or the slots in the presence of several) is covered in operation by a suitable cover device 14 around the area penetrated by the waveguide so that no cross-flow through a slot 11 can affect the measurement. The guide 6 can be varied by a height adjustment mechanism 15 (here, for example, as a fixed arms and an annular area around the Wurster tube, within which the Wurster tube can be moved up or down) in their distance from the distributor plate 3. The microwave radiation is reflected by the fluidized solid particles and received by the receiving unit. The evaluation is carried out by means of an integrated and / or separate evaluation electronics, preferably with respect to frequency and amplitude of the reflected signals. Deposits or non-moving particles can be suppressed by a frequency-selective evaluation. This has the significant advantage that it is possible to distinguish between a stationary particle bed and a fluidized particle flow. The proximal end 12 of the waveguide and thus the microwave sensor device 8 can be advantageously provided outside the outer wall 16 of the process plant and thus be easily accessible, so that the waveguide penetrates the outer wall 16. For this purpose, one or (if, for example, should be measured at different heights) several covered by suitable cover means that are not penetrated by the waveguides areas of the outer wall 16 to the waveguide and seal, covered holes in the outer wall 16 may be provided (for example, in a Wursteranlage GPCG15 in a height of 170 mm, 385 mm or 555 mm).

For installation in a process plant 1 with a plurality of guide devices 6, in particular Riser tubes, according to FIG. 2, the microwave sensor devices 8 may each be provided externally analogously as shown in Fig. 1. In this case, in particular, a central height adjustment mechanism 15 can be provided jointly for all guide devices 6, 9 is the waveguide, with the microwave radiation from and into the transmitting and receiving unit for microwaves of the microwave sensor device 8, which may also include a measuring electronics, in the interior of the guide 6 can be coupled. The spray nozzles 4 are shown here from above.

However, it may also be expedient and advantageous to arrange the microwave sensor devices 8 centrally according to FIG. 3, for example, next to and / or above one another in the middle of the process plant 1 - alternatively it can also be provided that the waveguides 9 each individually with only one central microwave sensor device in each case one transmitting and receiving unit are switched on (for example by means of a multiplexer mechanism which enables the connection of only one of a guide 6 coming waveguide 9, so that by means of only one microwave sensor device 8 still individual measurements for the individual by Leiteinrichtungen 6 (shown here as Wursterrohre In this case, the microwave sensor device (s) 8 and the waveguides 9 can be used together with the microwave sensor device independently of the central height adjustment mechanism 15 (here schematically simplified) ngen 8 shown) or in particular be directly connected to this (in other words, in the latter case, no separate arms of Höhenverstellmechanismus longer necessary, since the waveguide 9 take this function with, while in the first case connecting arms from the central height adjustment mechanism 15 to the baffles 6) and may lead from this singly or as a unit to the baffles 6 (here shown as risers). (2) In the interconnected configuration of waveguide and central height adjustment mechanism, a seal between wall 10 of a height adjustable baffle 6 and distal end 13 of the waveguide 9 omitted, since no slot 11 needs to be used. If the arms of the height adjustment mechanism 15 and the arms of the waveguide 9 or more waveguides 9 are guided separately to the individual guide devices 6, if a height adjustment is provided, each slot 11 per guide 6 expedient or, if the position of the waveguide is not changeable , Necessary and is preferably sealed in each case otherwise with a cover 14, which allows the passage of the waveguide or 9. For each guide 6 is preferably a separate microwave sensor device 8 and a waveguide 9 provide, but is also an embodiment as described above with only one microwave sensor device possible, which makes their measurements alternately on the individual waveguide. The measuring signals for the individual guide devices 6 can, if appropriate via evaluation electronics already integrated into the microwave sensor devices 8, be evaluated and visualized individually or jointly after forwarding to them in one or more evaluation units (for example also integrated in the system control).

Example 2: Calibration For operation, a microwave sensor device 8 must first preferably be calibrated. On the other hand, since no absolute values or mass flows are needed to assess the fluidization, it may be sufficient to set a microwave sensor device only in terms of its measuring range (ie without calibration), which is another preferred embodiment. For this purpose, a process plant 1, in particular a fluidized-bed plant according to the bottom-spray principle, or its coating container 2, is filled with an intended amount of particles and the plant is operated at the desired process gas rate (s) for a certain time at a particular setting and minimum and maximum values that occur during this process. The signal output of the microwave sensor device 8 supplies raw data values to a downstream (possibly integrated into the microwave sensor device) evaluation electronics. The evaluation electronics converts the raw signals into usable measurement signals which are then further processed, eg calibrated, visualized, stored (for example, by empirical means) directly by means of the evaluation electronics and / or by means of an evaluation and / or control unit which can be integrated in the system control To collect data for up- or down-scaling) and / or for (for example also automatic) control of the system. The calibration factors are preferably set so that in static product bed a zero signal and at maximum fluidization (= at least largely optimized product stream of fluidized particles for each spraying process, depending inter alia on the maximum amount entering the product stream particles per unit time and the Particle velocity, for example because at too high particle velocity (too high a process gas supply), for example, a spraying would not be sufficiently possible, so here a maximum meaningful Partikelstrom- and thus Prozessgasstromgeschwindig- speed are to be considered) a different from the zero signal and eg in the example a maximum ( or a measuring signal lying in the range of, for example, 25 to 100% of the maximum signal) is obtained. If the fluidization comes to a standstill or is it in varies their intensity, results at the Mikrowellensensorvorrichtungsausgaπg also a modified measurement signal, so that adjustments of the process parameters are possible.

According to the invention, the following areas of application can be covered with the aid of microwave sensors, which represents examples of the method according to the invention, wherein for the exemplary data obtained in FIGS. 4 to 6 a fluidized bed system GPCG15 as mentioned in example 1 with a Wurster tube with a diameter of 22, 86 cm and a height of 60 cm and a material thickness of 3 mm and via a corresponding waveguide a microwave sensor device of the type SolidFlow ^® (as mentioned above, to which a shunt resistor (470Ω) with a 16 bit analog / digital converter ( Conrad AD-USB 4, other analog inputs grounded via a 1 kΩ resistor) and a connection adapter connected to the output of the SolidFlow ^® transmitter FME, using the software supplied with the converter "AD-USB Data Monitor" is used to record the voltage, set the sampling rate of the converter, and record the data the computer to save and read in Excel, and read out via a RS485 to USB interface converter with the SWR software "FME configuration program" the calibration data of the transmitter FME or determined by the computer and calibration data for various products stored and all settings of the transmitter can be made) is used:

Example 3: Example of a method according to the invention for monitoring the

Fluidization in the process.

A separate microwave sensor device 8 is used for each guide 6 (in particular as a Wurster tube). During the fluidized bed process, each delivers a measuring signal. With uniform fluidization of the particles in the region of the product flow for the region of each guide 6, the measurement signals are almost identical and comparable. In plant control, for example, a mean value and the standard deviation of the signals can be calculated. The individual measured value of each microwave sensor device 8 can then be compared with this mean value. If the individual values of one or more devices 8 are below or above the mean value, the process can be interrupted or the plant operator can be informed. It is also possible to define limits for the mean value, which can cause an action to be undershot or exceeded. The standard deviation can also be evaluated from the mean value. If it rises above a certain limit, then an uneven process can be assumed. As possible Disturbances during a fluidized bed process can be called agglomeration, sticking or clogging in the area of the spray nozzle or product deposits in the area of baffles 6. If these problems are recognized in good time, the user can take targeted countermeasures and thus avert the destruction or damage of the product and thus economic damage. Especially for critical products that are prone to sticking or clogging of spray nozzles, this measurement method helps to ensure product quality. Given the exact knowledge of the process behavior and a risk analysis, the measuring method according to the invention is therefore an important development and can be part of the PAT (Process Analytical Technology) US FDA initiative "Guidance for Industry, PAT - A Framework for Innovative Pharmaceutical Development," Manufacturing, and Quality Assurance; Pharmaceutical cGMPs, September 2004 "are used as a means.

Example 4: Determination of a suitable position for a guide-tube device, here using the example of a riser position.

Not only in production plants, but also on a laboratory scale or in pilot plants, the microwave measurement can be used in baffles 6, in particular in Wurster tube, for example, to determine the distance between baffle 6 (e.g., riser) and baffle 3 during operation of a plant. The aim should be to achieve the most uniform possible fluidization at the selected position of the guide. The measurement signal is recorded at the desired amount of fluidizing air for a certain time. If the signal is non-uniform, as shown by way of example in FIG. 4, the position of the guide 6 is changed so far that a uniform signal is achieved.

In the example shown in FIG. 4, 30 kg of cellulose pellets having a diameter in the range from about 850 to about 1000 μm are fluidized at an air quantity of 1000 m ³ / h. The signal curve in FIG. 4 for a distributor floor riser distance of 40 mm clearly shows times at which more product is brought into the Wurster tube. The fluidization is restless, which is unsuitable for a uniform spray application. Through a sight glass this Fluidisierverhalten (product flow of fluidized particles) can only be seen by constant observation of the process. If the Wurster tube is set at a distance of 50 mm with otherwise identical test parameters, a much more uniform signal is displayed.

Thus, at the beginning of a new, unknown process, when the Basic parameters are not yet known, quickly and reliably determine parameters such as suitable riser distance or appropriate Fluidisierungsluftmenge. Also can be - especially in processes in which the particles presented grow quickly and thus change the fluidization - be recognized when improving the Ruidisierung over the entire process duration, the process gas quantity for fluidization increases and / or the distance of the riser to the distributor plate must be adjusted , By means of appropriate control algorithms, such processes can also be reproducibly automated.

Example 5: Setting the optimal process air quantity:

Even with a fixed position of a guide 6 (in particular Wurster tube position), the Ruidisierung can vary in the process according to the amount of process gas. With the aid of the measuring method according to the invention, however, it is possible to determine a process gas quantity at which the product flow in the region of the guide device 6 (in particular in the Wurster tube) is uniform. Although no direct quantitative inference can be made to the amount of particles transported in the product stream due to a slight speed dependence of the measurement without separate calibration of the measuring system at different process gas quantities, however, the method allows reliable conclusions about the uniformity of the fluidization.

An experimental example is shown in FIG. Therein, by way of example, 30 kg of cellulose pellets having a diameter in the range from about 850 to about 1000 μm are fluidized at process gas quantities of 750 m ³ / h and 1000 m ³ / h. The air volume of 750 m ³ / h is not enough to achieve even fluidization (or flow) at the given Wurster tube position, which is necessary for the overall test. If the amount of air is increased to 1000 m ³ / h, results in a more uniform fluidization of the submitted product.

Monitoring and eventual automatic control of the amount of process gas is necessary, for example, where products flow worse due to stickiness and a larger amount of process gas is needed for even fluidization during the process. There are also processes in which the fluidized particles have a large

Volume change experienced, which may be the case, for example, when applying large amounts of material. In this case, the fluidization behavior of the product also changes during the process and must be tracked. According to the invention, the changed fluidization behavior is recognized and, if necessary, one (in particular automatic) regulation of the process gas quantity.

Example 6 Determination of the Minimum Filling Quantity for Process Containers In a further example of application, the measuring method according to the invention for determining the minimum permissible product quantity in a process container is illustrated. Particularly in fluidized bed processes on a small scale, a plant is filled with as little product as possible. This saves costs at the beginning of the process development and the starting materials, which are often only available in small quantities. Nevertheless, it is important that the product is optimally fluidized in the process chamber. Therefore, there must not be too much product available to the process in the area of the guide, in particular in the riser. For a later transfer of the process data to the pilot or production scale, ideally an optimal fluidization in the sausage pipe is expected and the spraying rate of the spray nozzle is designed accordingly. If the fluidization in the riser pipe is not comparable on a smaller scale or on a larger scale, the calculations for process scale-up or scale-down performed therewith may be faulty. In practice, by using the microwave measuring technique, the minimum permissible filling quantity for a fluidized bed process can be determined.

In an exemplary experiment, sugar pellets with a diameter of 850-1000 μm are filled in stages in a 18 "Wurster coating container After each addition of pellets, the product is fluidized for two minutes at an intake air volume of 1000 m ³ / h The bottom plate of the Wurster tube is 50 mm, which shows an increase in the mean value of the measured signal as more pellets are fed in. The Wurster tube fills more and more until a plateau is reached for a quantity of 20 kg or more of pellets consequently a pellet quantity of 20 kg the minimum possible quantity at which scale-up or scale-down calculations can be performed reliably.

/ Claims

Claims

claims

Method for measuring, monitoring and / or regulating directional product movements of fluidized products in process plants (1) selected from vortex and spouted bed installations during a coating and / or granulation spray process, which comprises using one or more microwave sensor devices (8) - In particular contactless - microwave radiation is irradiated to one or more product streams, is received from the particles of the respective product stream reflected microwave radiation and due to the received microwave radiation, a measurement signal for characterizing the product flow is formed and output.

2. The method of claim 1, wherein the coupling of the microwave radiation in the outer region of the product stream or the product streams is made.

3. The method according to any one of claims 1 or 2, wherein one or more microwave sensor devices (8) are used, each having a transmitting and a receiving unit combined per measuring point.

4. The method according to any one of claims 1 to 3, wherein the coupling of the microwave radiation via one or more waveguide (9) is performed.

5. The method according to any one of claims 1 to 4, wherein each microwave sensor device (8) a transmitting and a receiving unit and a waveguide (9) are used, and wherein each waveguide (9) at the distal end (13) by one for the microwave radiation sufficiently permeable cover is closed.

6. The method according to any one of claims 1 to 5, wherein the coupling of the microwave radiation in the product stream to be examined is carried out in each case perpendicular or approximately perpendicular to the main direction of the product stream.

7. The method according to any one of claims 1 to 6, wherein the coupling of the microwave radiation to one or more guide means (6) which are provided within the outer wall (16) of the container of the process plant (1) is made, and wherein the coupling via Waveguide (9) is made, wherein the one or more distal ends (13) of the waveguide (9) or so are mounted such that they respectively penetrate a wall (10) of the one or more guide devices (6) and their distal end (13) faces the product flow approximately flush with the surface of the respective guide wall facing the product flow, whereas the proximal end (13) 12) is provided in each case on the non-product flow side facing the Leiteinrichtungs wall.

8. The method according to any one of claims 1 to 7, wherein the method is carried out in such vortex or spouted systems in which the product to be measured, monitored and / or regulated product flow is directed against gravity, in particular substantially upwards.

9. The method according to any one of claims 1 to 8, wherein the spraying is carried out in the context of the spraying process via one or more spray nozzles (4) in the form of single or multi-fluid nozzles, which are provided in the region of one or more distributor plates, substantially upwards ,

10. The method according to any one of claims 1 to 9, wherein it is in the process plant (1) is a working on the bottom spray process Wurster plant with one or more sausage pipes as guide devices (6).

11. The method according to any one of claims 1 to 10, wherein the product stream consists of particles having a size of 50 microns to 25 mm.

12. The method of claim 11, wherein the product stream consists of particles having a size of 200 microns to 10 mm.

13. The method according to any one of claims 1 to 12, wherein the product stream consists of pellets, coated pellets, tablets, granules, capsules, extrudates, crystals, powders, other particulate materials or correspondingly small objects.

14. The method according to any one of claims 1 to 11, wherein the reflected microwave radiation is evaluated in terms of frequency and amplitude.

15. The method according to any one of claims 1 to 14, which in terms of Microwave radiation is performed frequency selective.

16. The method according to any one of claims 1 to 15, wherein an evaluation of the or the obtained measurement signals by means of a respectively connected to the or the microwave sensor devices (8) evaluation and / or an evaluation and control unit, wherein in the latter the measurement results also directly to Regulation of the plant can be used is made.

17. The method according to any one of claims 1 to 16, wherein the measurement is carried out with a filter time or sampling rate of 0.2 to 200 seconds.

18. The method according to any one of claims 1 to 17, wherein the irradiated microwave radiation has a frequency of 1 to 100 GHz.

19. The method according to any one of claims 1 to 18, wherein the irradiated microwave radiation has a frequency of 24.125 GHz ± 100 MHz.

20. The method according to any one of claims 1 to 19, wherein a calibration of the obtained measurement signals for a process plant of a certain size is made and the data and information obtained are transferred to facilities with smaller or larger dimensions.

21. Use of one or more microwave sensor devices (8) in a method according to one of claims 1 to 20.

22. Use according to claim 21, wherein each microwave sensor device (8) has a transmitting and a receiving unit and a waveguide.

23. A device for carrying out a method according to one of claims 1 to 22, wherein it is a process plant (1) for coating and / or granulation in the form of a fluidized bed or jet bed system with one or more spray nozzles (4) and one or more Guiding devices (6) and having at least one microwave sensor device (8), characterized in that at least one within the process plant (1) located wall (10) of one of said guide devices (6) one of the intended directed

Product movement (7) in the form of a product stream facing Einkoppe- Having location for such a microwave sensor device (8) radiated microwave radiation and at least one intended product flow for a coupling point for reflected from particles of such a product stream microwave radiation.

24. An apparatus for carrying out a method according to one of claims 1 to 22, which is a process installation (1) for coating and / or granulation in the form of a fluidized bed or jet bed installation and which has at least one microwave sensor device (8), in particular arranged thereon, characterized in that they at least one boundary selected from the outer wall (16), the distributor plates (3) and / or located within the process plant guide devices (6) at least one of a planned directional product movement (7) in the form of a product stream facing coupling point for microwave radiation radiated by such a microwave sensor device (8) and at least one coupling point facing a product flow intended for microwave radiation reflected from particles of such a product flow

25. The apparatus according to claim 24, characterized in that it also has at least one open and closable side outlet for product removal in addition to the at least one distributor plate.

26. The device according to claim 25, characterized in that the process plant is equipped to produce a substantially horizontal circular product flow by means of at least one appropriately designed inflow floor and having at least one side open and closable outlet for lateral product removal.

27. The method according to any one of claims 1 to 22 using a device according to claim 25 or 26, which includes that the product removal - in particular automatically - when entering or reaching a certain property of the product stream or a corresponding resulting measurement signal of the microwave sensor device by the at least causes an open and closable lateral output or made and / or terminated. / Summary