Patent Publication Number: US-2022219187-A1

Title: Method for Monitoring a Nozzle Mouthpiece for Placing On a Nozzle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the United States national phase of International Application No. PCT/EP2020/056547 filed Mar. 11, 2020, and claims priority to German Patent Application No. 10 2019 205 737.3 filed Apr. 18, 2019, the disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Field 
     The invention relates to a method for monitoring a nozzle mouthpiece with regard to deposits on a nozzle for spraying substances, in particular dispersions, emulsions or suspensions, comprising a nozzle body which has a nozzle mouthpiece, wherein the nozzle body comprises an inner pipe, said inner pipe being connected to a feed for the substance to be sprayed and comprising an inner wall and an exit opening, and an outer pipe, said outer pipe being distanced to the inner pipe, being connected to a feed for a gas and comprising an exit opening, and the exit opening of the inner pipe and the exit opening of the outer pipe are arranged in the region of the nozzle mouthpiece. 
     Description of Related Art 
     Nozzles or spray nozzles are very often applied in industrial processes, such as for example granulation, the coating of tablets and pellets as well as the direct manufacture of pellets. Hereby, the particles are coated with a layer and/or a film. As a rule, liquids, in which solid matter is dissolved or suspended, are sprayed. These spraying processes can last for several hours. The liquid jet is atomised into small droplets by the atomisation. The droplet size which hereby arises is of huge significance to the manufacturing and/or spraying process. If the droplets are too small, then there is the danger that they dry before they reach their target, and if the droplets are too large, there is the danger of undesirable agglomerates arising. On account of the eddy in front of the nozzle which is inherent of the process—particularly with spraying processes which last for some time—deposits at the nozzle opening, thus a type of dross formation can occur. These deposits influence the symmetry and droplet size of the spray, so that effects upon the process which are not desirable, such as for example spray drying and/or local over-humidification and agglomeration occur. The droplet size can furthermore be influenced by way of the particles which are to be coated or treated settling or depositing in the feed for the substance to be sprayed or in the feed for the gas, in particular the atomisation gas. Such a settling or deposition in particular can be effected in time intervals, during which a spraying is not effected, for example on filling the device, in particular the fluidisation apparatus or drum coater, by way of the particles getting into the exit openings and these becoming blocked by way of this. 
     The closest state of the art presents technical solutions which prevent or at least minimise the undesirable deposits on the nozzle, in particular on the nozzle mouthpiece. 
     The European patent specification EP 1 497 034 B1 discloses a self-cleaning spray nozzle and in particular a self-cleaning nozzle for use in a device for the preparation of a particle material by way of a controlled agglomeration method. The self-cleaning spray nozzle comprises a middle pipe which has a middle passage for feeding a liquid, wherein the passage runs out into an opening for discharging a liquid, a second pipe which surrounds the middle pipe, by which means a first passage is formed between the middle pipe and the second pipe for feeding primary air, a nozzle cone which is arranged at the end of the second pipe and forms the outer periphery of a first outlet gap of the first passage, by way of which air which is fed to the first passage is mixed with the liquid, in order to form a liquid/air spraying mist, a third pipe which surrounds the second pipe, by which means a second passage is formed between the second and the third pipe for feeding secondary air, a sleeve which is arranged at the end of the third pipe and which forms the outer periphery of a second outlet gap of the second passage, wherein the nozzle cone is arranged at the end of the second pipe in an adjustable manner for adjusting the size of the first outlet gap. 
     A self-cleaning nozzle for spraying a fluid with a nozzle housing and with a nozzle head which is arranged therein, is designed in a multi-part manner and encloses a flow channel with an outlet opening for the fluid is described in the international patent application WO 2013/010930 A1, wherein the nozzle head comprises at least one stationary and at least one displaceably mounted head element which each form a section of the exit opening, wherein the displaceable head element the during normal operation is pressed by the fluid pressure against a stop which lies in the flow direction of the fluid and during the self-cleaning at a reduced fluid pressure is pressed by a spring counter to the flow direction. 
     The patent document DE 43 24 731 A1 discloses a self-cleaning spray nozzle for spraying a fluid from a pressurised medium source, wherein a tubular fitting is provided, said fitting comprising an inner fluid channel which runs in its longitudinal direction, is provided with an inlet and with an outlet and is provided with connection devices for creating a connection to the pressurised medium source; a tubular shank with an inlet and an outlet is provided, through which the fluid can be led, wherein the inlet of the shank reaches partly into the outlet-side end of the fitting in a manner such that the fluid which enters into the fitting flows through the shank in the longitudinal direction, said shank being provided with a flange; a valve seat with a skirt is provided, said skirt having an inner surface which is dimensioned such that it fits around the shank in a slidingly displaceable manner and comprising an outer surface which is dimensioned such that it fits into the outlet of the tubular fitting, in order to fix the radial position of the valve seat, wherein the valve seat furthermore comprises a lip which is dimensioned such that it positions the valve seat on the outlet of the tubular fitting in the longitudinal direction and forms a seal between the valve seat and the outlet of the tubular fitting; devices are provided, by way of which the valve seat is positively held in contact with the fitting, in order to prevent a displacement of the valve seat in the longitudinal direction and in the radial direction; a spray head with fastening devices for fastening the tubular shank is provided, wherein the spray head comprises outlet devices and has a surface which is adapted to the valve seat; a spring is provided, said spring surrounding the shank and being biased against the flange of the shank, in order to produce a fixedly defined biasing force against the valve seat, wherein the spring presses the valve seat against the adapted surface of the spray head, so that a sealing is formed between the valve seat and the adapted surface of the valve head, in order to limit the fluid flow at this sealing and wherein the outlet devices comprise such a channel for the fluid flow that this flow, when the sealing is created, is dispersed or sprayed according to a predefined pattern; wherein a force which is applied upon the spray head and which is sufficient in order to overcome the spring biasing separates the spray head from the valve seat, by which means the sealing effect is lifted and a rinsing of the outlet devices by the fluid is rendered possible. 
     The patent document DE 101 16 051 B4 discloses a spray nozzle for fluidised bed facilities, consisting of a nozzle body, a nozzle cap, at least one exit opening for a liquid which is subjected to solid materials and of at least one exit opening for a gas, wherein a flexible cleaning cap is arranged around the nozzle cap and a feed conduit which consists of a pressurised air channel which is arranged in the nozzle body and which is for a cleaning air which is subjected to pressurised air is arranged between the nozzle cap and the cleaning cap, wherein the pressured air channel is connected via an annular turned groove in the outer surface of the nozzle body and at least one transverse bore in the nozzle cap to an annular turned groove in the outer surface of the nozzle cap. The cleaning cap bears tightly on the nozzle cap in a direct manner. The feed of cleaning air which is subjected to pressurised air is effected via the pressurised air channel in adjustably different intervals or over a large time period. The cleaning air is fed via the annular turned groove and the transverse bore of the annular turned groove. The cleaning air is fed via the annular turned groove over the complete periphery between the nozzle cap and the cleaning cap. Due to the pressure impulse of the cleaning air, the cleaning cap which consists of an elastic material arches outwards, so that the cleaning air is led between the outer surface of the nozzle cap and the inner surface of the cleaning cap in the direction of the exit opening of the spray nozzle. The cleaning air is led as a pressure jet in an annular manner from all sides onto the nozzle mouth of the spray nozzle, so that the impulse of the jet can be used in a direct manner without losses and swirling can be avoided. Material deposits in the spray nozzle which arise in the direct proximity of the exit opening are blown away by the cleaning air. 
     The disadvantage of the aforementioned technical solutions is the fact that these self-cleaning nozzles which are mentioned in the state of the art each on the one hand have a large number of individual parts which are built together into complex nozzles which are maintenance-intensive, by which means the cited technical solutions are expensive in production and maintenance. Furthermore, it is possible for deposits or caking on the nozzles to occur despite the technical design of the nozzles which prevents such deposits and caking. 
     SUMMARY 
     It is therefore the object of the invention to provide a method for monitoring the self-cleaning nozzle, said method remedying the disadvantages of the state of the art. 
     Concerning a nozzle of the aforementioned type, this object is achieved in that an inlay is arranged on the inner pipe or on the outer pipe, wherein the inlay is arranged such that it can be brought or is brought into oscillation by way of the substance to be sprayed which exits out of the exit opening of the inner pipe and/or by way of the gas which flows out of the exit opening of the outer pipe, in order to minimise or prevent deposits in the exit region of the substance to be sprayed and/or of the gas, wherein a sensor which is connected to a control unit monitors the nozzle mouthpiece with regard to deposits and transmits signals to the control unit and given a deposition in the exit region of the substance to be sprayed and/or of the gas, said deposition being determined by the sensor, the control unit transmits a signal to a device. 
     Advantageously, by way of the method according to the invention, further deposits or caking which influence the symmetry and droplet size of the spray, on the nozzle mouthpiece in the region of the exit openings of the inner and outer pipe of the self-cleaning nozzle are recognised by the monitoring and are prevented or at least further minimised by way of suitable measures, so that undesirable effects upon the process such as a spray drying and/or local over-humidification and agglomeration does not occur. 
     Further advantageous embodiments of the method are described below. 
     According to a further development of the method according to the invention in view of this, the monitoring of the nozzle mouthpiece with regard to deposits is effected by way of a sensor which is arranged outside or within the nozzle. On account of the different process demands, it is sometimes useful to arrange the sensor within the nozzle, in particular in the case of spatially restricted conditions, for example with drum coaters or the like which have a small volume. Optical sensors, preferably cameras, particularly preferably high-speed cameras preferably monitor the nozzle mouthpiece from outside the nozzle. By way of this, a very good result is likewise achieved. 
     The method preferably comprises several sensors, in particular sensors which operate independently of one another. By way of the several sensors which are preferably independent of one another and operate independently of one another, it is possible to localise and identify deposits or a caking which negatively influence the symmetry and the droplet size, to an improved extent, so that the measure which is most suitable, for example vibration or pulse can be initiated. 
     Advantageously, a sensor transmits signals to the control unit and on exceeding a threshold value the control unit a signal to the device. The sensor already detects the smallest of deposits on the nozzle mouthpiece, thus in the region of the exit openings of the substance to be sprayed and/or of the gas. In order not to initiate a permanent reaction by the sensor, a threshold value, e.g., a minimum value of deposits or caking which is still acceptable for the spray quality can be specified to the sensor. If the threshold value is exceeded, the signal is transmitted from the sensor to the control unit, so that the control unit by way of transmitting a signal to the device initiates a suitable counter-measure for removing deposits. 
     Very preferably, the sensor is an optical sensor, in particular a camera, particularly preferably a high-speed camera, or a sensor which detects a physical measurement variable, in particular a pressure sensor or a differential pressure sensor. The possibility of optically detecting the contamination is given due to the optical sensors. By way of the sensors which detect a physical measurement variable, for example the mass flow and hence also the volume flow of the substance to be sprayed and/or of the atomisation gas can be computed from the differential pressure, so that information concerning the deposits or caking on the nozzle mouthpiece can be provided. Deposits or caking on the nozzle mouthpiece lead to a pressure increase in front of the exit openings in the fluid channel or annular gap and hence to a greater flow speed of the substance to be sprayed and/or of the gas, so that given a suitable specification of threshold values or tolerance ranges (for example ±10% deviation) and given them being exceeded or fallen short of, the control unit initiates a suitable counter-measure for removing deposits by way of transmitting a signal to the device. 
     According to an additional embodiment of the method according to the invention, a device which receives a signal from the control unit is a vibration unit or a pulsation unit. Hereby, the vibration unit is connected to the nozzle and on receiving a signal from the control unit brings the nozzle into vibration, so that the deposits on the nozzle mouthpiece detach. Alternatively, on receiving a signal from the control unit, the pulsation unit imparts a pulse upon the substance which is to be sprayed and which is led in the fluid channel and/or upon the gas, which is led in the annular gap, so that the deposits on the nozzle mouthpiece detach. The imparted pulse can have different frequencies, in particular between 1 Hz and 1500 Hz, preferably between 25 Hz and 250 Hz. By way of this, deposits or caking on the nozzle mouthpiece in the region of the exit openings of the inner and outer pipe are detached and removed to an improved extent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is hereinafter explained in more detail by way of the accompanying drawings. They are shown in 
         FIG. 1  a nozzle according to the state of the art, 
         FIG. 2  a section B-B according to  FIG. 4  through a first embodiment of a preferred nozzle, 
         FIG. 3  a detailed view of a part of the nozzle mouthpiece of the first embodiment of the preferred nozzle according to detail A of  FIG. 2 , 
         FIG. 4  a plan view upon the first embodiment of a preferred nozzle according to  FIG. 2  with a section plane B-B which intersects the axis X-X, 
         FIG. 5  a section through a second embodiment of a preferred nozzle with an attachment part in the annular gap, in the form of a swirl plate for leading gas, 
         FIG. 6  a section through a third embodiment of a preferred nozzle with an attachment part in the form of a swirl plate for leading gas in the annular gap, 
         FIG. 7  a section through a fourth embodiment of a preferred nozzle, 
         FIG. 8  a section through a fifth embodiment of a preferred nozzle, 
         FIG. 9  a section through a sixth embodiment of a preferred nozzle, 
         FIG. 10  a section through a seventh embodiment of a preferred nozzle, 
         FIG. 11  a section through a preferred nozzle according to the first embodiment, wherein the nozzle comprises a nozzle needle which is displaceable in the axial direction, for closing the exit openings of the nozzle, 
         FIG. 12  a section through a preferred nozzle, wherein the inlay and the inner pipe form a single-piece inner conduit of the preferred nozzle, 
         FIG. 13  a section through preferred nozzle, wherein the inlay and the inner pipe form an inner conduit of the preferred nozzle and the preferred nozzle in the region of the nozzle mouthpiece between the inner and outer pipe comprises a device which is changeable in its volume, wherein the device in  FIG. 13  shows an open position of the preferred nozzle, 
         FIG. 14  a section through a preferred nozzle, wherein the inlay and the inner pipe form an inner conduit of the preferred nozzle and the preferred nozzle in the region of the nozzle mouthpiece between the inner pipe and the outer pipe comprises a device which is changeable in its volume, wherein the device in  FIG. 14  shows a closure position of the preferred nozzle, 
         FIG. 15  a schematic construction of a first method for monitoring the nozzle mouthpiece of a first embodiment of the preferred nozzle and 
         FIG. 16  a schematic construction of a second method for monitoring the nozzle mouthpiece of a first embodiment of the preferred nozzle. 
     
    
    
     DETAILED DESCRIPTION 
     A nozzle  1  which is known from the state of the art is represented in  FIG. 1 . The nozzle  1  comprises a nozzle body  4  which comprises an inner pipe  2  and an outer pipe  3 . The inner pipe  2  and the outer pipe  3  are hereby arranged coaxially to an axis X-X. The inner pipe  2  comprises a fluid channel  5  which is designed for feeding the substance to be sprayed, preferably a liquid, very particularly preferably a dispersion, suspension, or emulsion. This fluid channel runs out in the region of the nozzle mouthpiece  6  into an exit opening  7  of the inner pipe  2 . In the region which is away from the exit opening  7  of the inner pipe  2 , the inner pipe  2  comprises a connection location  10  for a feed conduit for the substance to be sprayed, said feed conduit not being represented. 
     The outer pipe  3  is arranged distanced to the inner pipe  2 , by which means an annular gap  8  for feeding the gas, in particular atomisation air forms. The annular gap  8  runs out into an exit opening  9  of the outer pipe  3  in the region of the nozzle mouthpiece  6 . In the region which is away from the exit opening  9  of the outer pipe  3 , the outer pipe  3  comprises a connection location  11  for a feed conduit for the gas, said feed conduit not represented. 
       FIG. 2  shows a section B-B according to  FIG. 4  through a first embodiment of preferred nozzle  101 . The preferred nozzle  101 , as already represented in  FIG. 1 , comprises a nozzle body  104  which has an inner pipe  102  and an outer pipe  103 . The inner pipe  102  and the outer pipe  103  are arranged coaxially to an axis X-X. 
     The inner pipe  102  comprises a fluid channel  105  for feeding the substance to be sprayed, preferably a liquid, very particularly preferably a dispersion, suspension, or emulsion. This runs out into an exit opening  107  of the inner pipe  102  in the region of the nozzle mouthpiece  106 . In the region which is away from the exit opening  107  of the inner pipe  102 , the inner pipe  102  comprises a connection location  110  for a feed conduit for the substance to be sprayed, said feed conduit not being represented. The outer pipe  103  is arranged in a manner distanced to the inner pipe  102 , by which means an annular gap  108  for feeding the gas, in particular atomisation gas forms. The annular gap  108  runs out into an exit opening  109  of the outer pipe  103  in the region of the nozzle mouthpiece  106 . Preferably, the exit opening  107  of the inner pipe  102  and the exit opening  109  of the outer pipe  103  are arranged concentrically to one another. By way of this, it is ensured that the flow conditions of the gas which is delivered in the annular gap  108  are formed in an optimal, in particular uniform manner, so that the symmetry and droplet size of the spray which is produced by way of the preferred nozzle  101  are matched precisely to the demands of the manufacturing and/or spraying process, in particular manufacturing process and/or spraying process for granulates, tablets or the like. A connection location  111  for a feed conduit for the gas, said feed conduit not being shown, is given in the region which is away from the exit opening  109  of the outer pipe  103 . Preferably, the exit openings  107 ,  109  lie in a plane C-C and run out into the exit region  112  of the nozzle  101 . In the exit region  112 , the spray which coats the particles is produced by the colliding of the substance to be sprayed and the atomisation gas. Advantageously, the symmetry as well as the droplet size of the spray is set in an optimal manner during the manufacturing process and/or spraying process. 
     The inner pipe  102  comprises an inlay  113 . The inlay  113  in  FIG. 2  is arranged in its preferred position on an inner wall  114  of the inner pipe  102 . The inlay  113  is preferably manufactured from a polymer, particularly preferably from a synthetic polymer, very particular preferably for a silicone. Polymers are multi-faceted materials which given a simultaneous high robustness are manufacturable in an inexpensive manner and can be very temperature-resistant depending on the polymer. The polymers, in particular the synthetic polymers are therefore very suitable as an inlay  113  for the most varied of different manufacturing processes and/or spray processes. The preferred nozzle  101  can be applied in the most varied of manufacturing processes and/or spray processes on account of the exchangeability of the inlay  113 . 
     The inlay  113  in the first embodiment of the preferred nozzle  101  comprises four part-sections  115  to  118 . The part-section  115  secures the inlay  113  in the nozzle  101 , so that the inlay  113  is arranged in the preferred nozzle  101  during the complete manufacturing and/or spraying process. Advantageously, the inlay  113  is connected to the inner pipe  102  such that this is fixed there. The part-sections  116  and  117  in the preferred nozzle  101  are arranged between the part-section  115  and the part-section  118  and bear on the inner wall  114  of the inner pipe  102 . The part-section  118  of the inlay  113  projects at least partly out of the exit opening  107  of the inner pipe  102 . By way of the possibility of the adjustment of the holding point of the part-sections  115  on the inner pie  102 , the length of the part-section  118  of the inlay  113  which projects out of the exit opening  107  of the inner pipe  102  can be changed. 
       FIG. 3  shows a detailed view of a part of the nozzle mouthpiece  106  of the first embodiment of the preferred nozzle  101  according to detail A of  FIG. 2 . The inner pipe  102  and the outer pipe  103  are arranged coaxially about the axis X-X, so that the exit openings  107 ,  109  are arranged concentrically about the intersection point of the axis X-X with the plane C-C. The exit opening  107  of the inner pipe  102  and the exit opening  109  of the outer pipe  103  furthermore lie in the plane C-C and run out into the exit region  112  of the nozzle  101 . The spray which coats the particles is produced in the exit region  112  by way of the collision of the substance to be sprayed and the atomisation gas. Advantageously, the symmetry as well as the droplet size of the spray is adjusted during the manufacturing and/or spraying process. 
     The part-section  117  of the inlay  113  bears on the inner wall  114  of the inner pipe  102  of the preferred nozzle  101  and is connected to the part-section  118  of the inlay  113 . The part-section  118  of the inlay  113  projects at least partly out of the exit opening  107  of the inner pipe  102  of the preferred nozzle.  101 . The part-section  118  of the inlay  113  is preferably changeable in length. The length changeability is represented by the dotted line which is adjacent to the part-section  118 . The length change can either be effected in a direct manner by way of exchanging the inlay  113 , by way of adjusting the holding point of the inlay  113  on the inner pipe  102  and/or any other change of the arrangement of the inlay  113  in the nozzle  101 . 
     An inner pressure  119  acts upon the inlay  113  by way of the substance to be sprayed, preferably a liquid, particularly preferably a dispersion, suspension or emulsion, which is conveyed in the fluid channel  105  in the direction of the exit opening  107  through the inner pipe  102  which comprises an inlay  113 . The inlay  113  is pressed against the inner wall  114  of the inner pipe  102  by way of the inner pressure  119  which acts upon the inlay  113 . In the region of the nozzle mouthpiece  106 , in particular in the region of the exit opening  107  of the inner pipe  102 , a force which moves the inlay  113  away from the axis X-X likewise acts upon the part-section  118  of the inlay  113  by way of the inner pressure  119  which acts upon the inlay  113 . 
     Furthermore, a force  120  which acts in the direction of the axis X-X acts upon the part-section  118  of the inlay  113  which projects at least partly out of the exit opening  107  of the inner pipe  102 . The force  120  which acts in the direction of the axis X-X is created by the gas, in particular atomisation air, which exits from the exit opening  109  out of the annular gap  108 . 
     By way of this, the inlay  113  which projects at least partly out of the exit opening  107  of the inner pipe  102  is moved, advantageously in a high-frequency manner, by the liquid which exits out of the preferred nozzle  101  into the exit region  112  of the nozzle  101  and/or by the gas, in particular atomisation gas which exits out of the preferred nozzle  101  into the exit region  112  of the nozzle  101 . Due to this advantageously high-frequency movement of the inlay  113  which projects at least partly out of the exit opening  107  of the inner pipe  102 , deposits of the liquid to be atomised, on the nozzle mouthpiece  106 , in particular in the exit region  112 , or their agglomeration, is prevented. The symmetry and droplet size of the spray is therefore not influenced during the manufacturing and/or spraying process, so that an undesirable spray drying and/or a local over-humidification and agglomeration does not occur. 
     The vibration frequency of the part section  118  of the inlay  113  can be additionally changed for example by way of the length changeability of the part-section  118  of the inlay  113 . By way of this, one can have a direct influence upon the manufacturing and spraying process. A further change of the vibration frequency is possible for example by way of adapting the pressures of the substance or gas which is to be sprayed. A change of the onflow angle a of the gas, in particular of the atomisation air also effects a change of the vibration frequency of the inlay  113  and therefore has an influence upon the spray and its quality, in particular with regard to the symmetry and the particle size. The arrangement of the outer pipe  103  and the inner pipe  102  to one another is to be adapted, in particular in the region of the nozzle mouthpiece  106 , for changing the onflow angle a of the gas. Furthermore, the onflow of the inlay  113  can also be adapted by way of a changed flow guidance in the annular gap  108 . Very preferably, it is only the annular gap  108  which is adapted, so that this has a different onflow angle with respect to the part-section  118  of the inlay  113 . 
       FIG. 4  shows a plan view upon the first embodiment of a preferred nozzle  101  with a section plane B-B which intersects the axis X-X. The inner pipe  102  and the outer pipe  103  are aligned coaxially to the axis X-X, so that the exit openings  107 ,  109  for the substance to be sprayed, in particular a liquid, very particularly preferably a dispersion, or for the gas, in particular atomisation air, are arranged concentrically to one another about the axis X-X. The inlay  113  is arranged on the inner wall  114  of the inner pipe  102 . 
     A section through a second embodiment of a preferred nozzle  201  with an optional attachment part  220  in the annular gap  208  in the form of a swirl plate for the guidance of the gas is represented in  FIG. 5 . 
     The preferred nozzle  201  according to the second embodiment in its basic construction corresponds to the first embodiment of the preferred nozzle  101  which is shown in  FIGS. 2 to 4 . The difference between the two embodiments is the fact that the preferred nozzle  201  in contrast to the nozzle  101  comprises an optional attachment part  221  which is designed in the form of a swirl plate for leading the gas. In the present second embodiment of the preferred nozzle  201 , the attachment part  221  comprises openings  222  which are at an angle to the gas, in particular atomisation gas, which flows parallel to the outer pipe  203 . By way of this, the gas which flows in the annular gap  208  undergoes a swirling about the axis X-X. The onflow and the movement behaviour and thus also the vibration frequency of the inlay  213  which projects at least partly out of the exit opening  207  of the inner pipe  202  can be influenced by the swirling about the axis X-X. 
     The attachment part  221  can likewise be designed in the form of swirl bodies, e.g., flow guide plates or the like, for leading the gas. The attachment part  222  is preferably fixedly connected to the inner pipe  202  and to the outer pipe  203 . By way of this, the stability of the nozzle  201  in the region of the nozzle mouthpiece  206  is increased. Furthermore, due to the installation of an attachment part  221  in the form of swirl bodies, swirl plates or the like, the leading of the flow of the gas, in particular of the atomisation air, at the nozzle mouthpiece  206 , in particular in the exit region  212  of the nozzle  201  is influenced, by which means the movement behaviour of the inlay  213  which projects at least partly out of the inner pipe  202 , in particular the vibration frequency of the part-section of the inlay  213 , can be changed. The vibration frequency is therefore adjustable to the manufacturing and/or spraying process to an improved extent. Additionally, by way of this, the spray symmetry, and the droplet size of the spray, i.e., of the substance to be atomised, preferably of a liquid, very particularly preferably of a dispersion, emulsion or suspension can be adjusted in a direct manner. Furthermore, on installing, the inner pipe  202  is led in outer pipe  203  and always held in the desired position, in  FIG. 5  in a concentric position about the axis X-X. Furthermore, the attachment part  221  prevents an oscillation of the inner pipe  102 , which leads to a change of the exit openings  207  of the inner pipe  202  as well as of the exit openings  207  of the outer pipe  203 , which changes the flow conditions at the nozzle mouthpiece  206 , in particular in the exit region  212  of the nozzle  201  and thus also influences the spray geometry and the droplet size of the spray. Preferably, the inlay  213  which projects at least partly out of the exit opening  207  of the inner pipe  202  has a variable wall thickness. The wall thickness of the inlay  213 , in particular of the part-section  218  which projects out of the inner pipe  202  can be adapted to the substance to be sprayed, preferably a liquid, particularly preferably a dispersion, emulsion or suspension, by which means the spray behaviour, preferably the spray symmetry and the setting of the droplet size, of the preferred nozzle  201  can be optimised. The inlay  213  can hence also be adapted to abrasive substances which are to be sprayed. By way of the change of the wall thickness given an equal length of the inlay  213  which projects at least partly out of the inner pipe  202  or by way of adapting the length of the inlay  213  given an equal wall thickness of the inlay  213 , the oscillation behaviour of the part-section  218  which projects at least partly out of the exit opening  207  is changed, by which means the applied inlay  213  is specially adapted to the respective process with regard to method technology. The inlay  213  is advantageously connected to the inner pipe  202 , so that this is fixed there. 
       FIG. 6  shows a section through a further, third embodiment of a preferred nozzle  301  with an optional attachment part  321  in the annular gap  308  in the form of a swirl plate for leading gas. The preferred nozzle  301  comprises a nozzle body  304  which has an inner pipe  302  and an outer pipe  303 , wherein the inner pipe  302  and the outer pipe  303  are arranged coaxially to an axis X-X. The inner pipe  302  comprises a fluid channel  305  which is designed for feeding the substance to be sprayed. This channel opens out into an exit opening  307  of the inner pipe  302  in the region of the nozzle mouthpiece  306 . In the region which is away from the exit opening  307  of the inner pipe  302 , the inner pipe  302  comprises a coupling location  310  which for a feed conduit for the substance to be sprayed, preferably a liquid, very particularly preferably a dispersion, emulsion, or suspension, said feed conduit not being shown. 
     The outer pipe  303  is arranged in a manner distanced to the inner pipe  302 , by which means an annular gap  308  for feeding the gas, in particular atomisation air, forms. The annular gap  308  runs out into an exit opening  309  of the outer pipe  303  in the region of the nozzle mouthpiece  306 . In the region which is away from the exit opening  309  of the outer pipe  303 , the outer pipe  303  comprises a coupling location  311  for a feed conduit for the gas, said feed conduit not being shown. 
     An attachment part  321  which comprises an opening  322  is arranged between the inner pipe  302  and the outer pipe  303 . The attachment part  321  connects the inner pipe  302  and outer pipe  303  to one another, preferably in a fixed manner. By way of the attachment part  321 , a swirl is imparted upon the gas, in particular the atomisation air, which flows through the annular gap  308 . The frequency of the inlay  313  which projects at least partly out of the exit opening  309  of the out pipe  303  is influenced by way of the swirling. The inlay  313  is arranged on the outer wall  323  in the annular gap  308  and bears on the outer wall  33 . 
     The inlay  313  which projects at least partly out of the exit opening  309  of the outer pipe  303  into the exit region  312  comprises four part-sections  315 ,  316 ,  317  and  318 . Part-section  315  is fixed, for example clamped in a groove  324  which is arranged on the outer wall  323 . The part-sections  316  and  317  connect the part-sections  315  and  318 . The length of the inlay  313  is changeable, in particular the length of the part section  318  of the inlay  313  is adaptable to the parameters of the manufacturing and/or spraying process. Furthermore, the wall thickness of the inlay  313  which projects at least partly out of the exit opening  309  of the outer pipe  303  into the exit region  312 , in particular the wall thickness of the part section  318  of the inlay  313  is adaptable to the process parameters with regard to method technology. In  FIG. 6 , the wall thickness of the inlay  313  decreases from the part section  315  to the part section  318 . 
     The inlay  313  which projects at least partly out of the exit opening  309  of the outer pipe  303  into the exit region  312  is moved in particular at a high frequency by way of the substance, in particular a liquid, which is to be sprayed and which exits out of the preferred nozzle  301 , and/or by way of the gas, in particular the atomisation gas, which exits out of the preferred nozzle  301 . By way of the in particular high-frequency movement or oscillation of the inlay  313  which projects at least partly out of the exit opening  309  of the outer pipe  303  into the exit region  312 , vibrations at a certain frequency arise at the inlay  313 , by which means caking or adhesion of the substance to be sprayed, preferably a liquid, very particularly preferably a dispersion, emulsion, or suspension, which leads to deposits on the nozzle mouthpiece  306 , is prevented. Due to the prevention of deposits on the nozzle mouthpiece  306  in the exit region  312  and/or due to the prevention of agglomeration of the substance to be sprayed, the symmetry and droplet size of the spray are not influenced during the manufacturing and/or spraying process, so that an undesirable spray-drying and/or a local over-humidification and agglomeration does not occur. 
       FIGS. 7 to 10  show further four embodiments of the preferred nozzle  401 ,  501 ,  601 ,  701  as a sectioned representation, whose construction shape does not generally differ from the first embodiment of the nozzle  101 . In particular, the embodiments differ from the first embodiment of the preferred nozzle  101  in that the inlay  413 ,  513 ,  613  and  713  is arranged at a different position on the inner pipe  402 ,  502 ,  602 ,  702  or outer pipe  403 ,  503 ,  603 ,  703 . Hereinafter, the four embodiments of the preferred nozzle  401 ,  501 ,  601 ,  701  are described in more detail. 
     Hereby, a section through a fourth embodiment of a preferred nozzle  401  is shown in  FIG. 7 . The inlay  413  in the fourth embodiment of the preferred nozzle  401  is arranged in a wall  425  of the inner pipe  402  and its part-section  418  projects into the exit region  412  of the nozzle  401 . The inlay  413  according to the fourth embodiment comprises two part-sections  417  and  418 , wherein the part-section  417  serves for fastening the inlay  413  in the wall  424  of the inner pipe  402 . Advantageously, the inlay  413  is clamped in the wall  425  of the inner pipe  402  or the like, so that this is fixed there. 
     A section through the fifth embodiment of a preferred nozzle  510  is shown in  FIG. 8 . According to  FIG. 8 , the inlay  513  in the fifth embodiment of the nozzle  501  is arranged on an inner wall  526  of the outer pipe  503 . The inlay  513  hereby comprises four part-sections  515 ,  516 ,  517  and  518 , wherein the part-section  518  projects out of an exit opening  509  of an outer pipe  503  at least partly into an exit region  512 . The inlay  513  is arranged in a groove  527  in the inner wall  526  of the outer pipe  503  by way of the part-section  515  and is fixed there, for example by way of pressing. 
     A section through a sixth embodiment of a preferred nozzle  601  is represented in  FIG. 9 , wherein the inlay  613  in the sixth embodiment of the nozzle  610  is arranged in a wall  628  of the outer pipe  603 . The inlay  613  is hereby arranged in a wall  628  of the outer pipe  603  and its part-section  618  projects into the exit region  612  of the nozzle  601 . The inlay  613  according to the sixth embodiment comprises two part-sections  617  and  618 , wherein the part-section  617  serves for fastening the inlay  613  in the wall  628  of the outer pipe  603 . Advantageously, the inlay  613  is clamped or the like in the wall  628  of the outer pipe  603 , so that this is fixed there. 
       FIG. 10  shows a seventh embodiment of the preferred nozzle  701 , wherein the inlay  713  is arranged on an outer wall  729  of the outer pipe  703 . According to  FIG. 10 , the inlay  713  in the seventh embodiment of the nozzle  701  is arranged on an outer wall  729  of the outer pipe  703 . The inlay  713  hereby comprises four part-sections  715 ,  716 ,  717 , and  718 , wherein the part-section  718  at least partly projects into an exit region  712 . The inlay  713  is arranged in a groove  730  in the outer wall  729  of the outer pipe  703  by way of the part-section  715  and is fixed there, for example clamped or pressed. 
     All embodiments  101  to  701  can comprise an optional attachment part  101  to  701  for leading the flow in the annular gap  108  to  708 . Furthermore, there is the possibility of the arrangement of an inlay  113  to  713  on the inner pipe  102  to  702  and of an additional inlay  113  to  713  on the outer pipe  103  to  703 , so that the preferred nozzles  101  to  701  comprise two inlay  113  to  713 . 
       FIG. 11  represents a section through a preferred nozzle  801  according to the first embodiment, wherein the nozzle  801  according to  FIG. 11  comprises a nozzle needle  813  which is displaceable in the axial direction of the axis X-X for the closure of the exit opening  807  of the inner pipe  802  of the nozzle  801 . By way of the axial displacing of the nozzle needle  831  in the Z-direction along the axis X-X out of the home position according to  FIG. 11  into an end position which is represented dashed, the exit opening  807  of the inner pipe  802  of the nozzle  801  which comprises the inlay  813  is closed. By way of this, the exit of a substance to be sprayed from the preferred nozzle  801  is prevented. Furthermore, there exists the possibility of also displacing the inner pipe  802  in the Z-direction, additionally to the nozzle needle  831 , so that the exit opening  807  of the inner pipe  802  of the nozzle  801  as well as the exit opening  809  of the outer pipe  803  of the nozzle  801  is closed. A widening of the inner pipe  802  by way of the nozzle needle  831  is also possible. By way of this, in the case for example of a filling of a granulator, a coater, in particular of a drum coater, or a fluidisation apparatus, one succeeds in pellets or particles being prevented from penetrating into the exit openings  807 ,  809  of the nozzle  801  and this therefore becoming blocked already before the beginning of the manufacturing process. Preferably, hereby the inner pipe  802  and the inlay  813  are designed as one piece as a conduit, preferably in the form of an elastic material, preferably a silicone. Furthermore, by way of this one prevents the inlay  813  dislocating with respect to the inner pipe  802  due to the displacement of the nozzle needle  813 . 
     A section through a preferred nozzle  901  is shown in  FIG. 12 , wherein the inlay  913  and the inner pipe  902  of the preferred nozzle  901  are designed as one piece as a conduit  932 . The inlay  913  and the inner pipe  902  however can just as easily be designed as two separate components. According to this embodiment, the inlay  913  and the inner pipe  902  form the inner conduit  932 . This is preferably manufactured of an elastic material, preferably of a polymer, in particular of a silicone. Advantageously, by way of this, it is even simpler to be able to exchange the inner conduit  932  of the preferred nozzle  901  which comprises the substance to be sprayed. Furthermore, there is the possibility of designing the inner conduit as a disposable article, which for example in the pharmaceutics industry in the case of a change of the substance to be sprayed, on account of a change of product leads to considerable advantages and a significant simplification of the working process in comparison to a cleaning of the inner pipe  902 . According to  FIG. 12 , in particular the part-sections  918  which project out of the exit openings  909  of the outer pipe  903  into the exit region  912  are designed with a very low thickness. The wall  925  of the inner pipe  902  is advantageously designed with a larger wall thickness than the part-section  918  for reasons of stability of the inner pipe  918 . Very particularly preferably, the heavily loaded wall sections are likewise designed in a reinforced manner, for example by way of a polymer or the like which is fibre-reinforced at this location. 
       FIGS. 13 and 14  show a further preferred embodiment of a nozzle  1001  with a device  1033  which can be changed in its volume.  FIG. 13  shows a section through a preferred nozzle  1001 , wherein the inlay  1013  and the inner pipe  1002  form a conduit  1032 , preferably of a single piece, of the nozzle  1001 . The conduit  1032  is designed at least partly from an elastic material, in particular from a polymer and very preferably from a silicone, and a device  1033  which can be changed in its volume, in particular an inflatable pressurised air ring or the like is arranged in the region of the nozzle mouthpiece  1006  in the annular gap  1008  between the inner pipe  1002  and the outer pipe  1003 . 
     The device  1033 , in particular the pressurised air ring, which is changeable in its volume comprises at least one inlet for a fluid feed and at least one outlet for a fluid discharge, said inlet and outlet not being represented here. By way of this, the volume of the device  1033  can be changed, specifically can be enlarged, or reduced in size by way of the feed or discharge of fluid, by which means the device  1033  can be brought or is brought from an open position which is shown by way of example in  FIG. 13  into a closure position which is shown in  FIG. 14 , or vice versa. The closure position is always given as soon as the inner pipe  1002  is closed by the device  1033 , independently of the opening degree of the annular gap  1008 , through which the gas, in particular the atomisation air flows. In the open position which is shown in  FIG. 13 , on the one hand the gas can flow through the annular gap  1008  and on the other hand the substance to be sprayed, in particular a liquid or dispersion can flow through the fluid channel  1005 , by which means the gas can atomise the substance to be sprayed at the exit. Advantageously, the device  1033  has no or a negligible influence upon the flow of the gas which flows through the annular gap  1008 . 
     It should always be noted that the substance to be sprayed, in particular the liquid should not exit from the nozzle  1001  in a non-atomised state. For this, it is to be ensured that at the beginning of each spraying procedure, it is firstly gas, in particular atomisation gas which flows through the annular gap  1008  and thus out of the nozzle  1001  and subsequently the substance to be sprayed, in particular the liquid. On completing the spraying procedure, firstly the feed of the substance to be sprayed is to be stropped or interrupted and subsequently that of the gas. By way of this, it is ensured at all times than given a spraying procedure, the substance to be sprayed is atomised and that no substance to be sprayed drips out of the nozzle, possibly onto (coated) material to be treated, in a non-atomised state at the end of each spraying procedure. On starting or ending a spraying procedure, this can be ensured for example by way of an automatic “leading” and “trailing” of the gas. 
     All positions, in which fluid can flow through the annular gap  1008  and/or the fluid channel  1005  are denoted as an open position. By way of this, it is possible to provide an infinite adjustment of the volume flow with a through-flow of 0% and 100% for the gas and for the substance to be sprayed, wherein the adjustment of the volume flows is dependent on one another given only one device  1033 . With the application of several, in particular two devices  1033 , specifically each for the substance which is to be spayed which is conveyed in the fluid channel  1005  and the gas which is conveyed in the annular gap  1008 , the volume flows of the substance to be sprayed in the fluid channel  1005  of the inner pipe  1002  and of the gas in the annular gap  1008  can be adjustable independently of one another and can be adjusted independently of one another, specifically by way of volumes of the applied devices  1033  which can be changed independently of one another by way of fluid feed or fluid discharge. By way of the independent adjustability of the volumes of different devices  1033 , an optimal adaption of the volume flow of the substance to be sprayed to the atomisation gas and vice versa is likewise possible. By way of this, one can also react to the smallest changes of symmetry or particle size in the spray. The devices  1033  for the substance to be sprayed and for the gas are closed-loop controlled and/or controlled independently of one another by way of control devices and/or closed-loop control devices which are not shown here. 
     The device  1033  is preferably arranged concentrically around the conduit  1032  and is enclosed by the outer pipe  1003 , wherein a part-section  1018  projects at least partly out of the exit opening  1009  of the outer pipe  1003  into the exit region  1012 . In  FIG. 13 , the device  1033  is designed annularly about the inner pipe  1002 . The device  1033  is preferably designed as a pressurised air ring. The device  1033  however can also be designed in any conceivable other embodiment. 
     The device  1033  is preferably connected to a closed-loop control or control device which is not shown here and which closed-loop controls or controls the fluid feed or fluid discharge to and from the device  1033 , so that the volume of the device  1033  can be set or is set. Very particularly preferably, the volume of the device  1033  is infinitely changed or infinitely changeable by way of the fluid feed or the fluid discharge or the volumes of the devices  1033  are infinitely changeable or changed by way of the fluid feed or fluid discharge. By way of the infinite adjustability of the volume of the device  1033  or of the devices  1033 , it is possible to adjust the volume flows of the substance to be sprayed and of the gas which atomises the substance to be sprayed, to one another in a precise and targeted manner, so that the symmetry and the droplet size of the spray is set or can be set in an optimal manner for the process, in particular for the coating process of particles, preferably tablets. In  FIG. 13 , the volume of the device  1033  is minimal, so that the nozzle  1001  is situated in the maximal open position. The maximal open position is accordingly characterised in that the device  1033  has a minimal volume. A section through the preferred nozzle  1001  is shown in  FIG. 13 , wherein the inlay  1013  and the inner pipe  1002  form a conduit  1032  of the preferred nozzle  1001  and the preferred nozzle  1001  in the region of the nozzle mouthpiece  1006  between the inner pipe  1002  and the outer pipe  1003  comprises a device  1033  which changeable in its volume, wherein the device in  FIG. 14  represents a closure position of the preferred nozzle by way of the device  1033  closing the fluid channel  1005  and the annular gap  1008 . The inlay  1013  is brought into oscillation, in particular a high-frequency oscillation by way of the substance which is to be sprayed which exits through the exit opening  1007  of the inner pipe  1002  and/or by way of the gas which exits through the exit opening  1009  of the outer pipe  1003 , in order to minimise or completely prevent deposits in the exit region  1007 ,  1009  of the substance to be sprayed and/or of the gas. Preferably, a part-section  1018  of the inlay  1013 , in particular during the spraying procedure, can also be changed in length. On account of the additional length changeability of the part-section  1018  of the inlay  1013  which projects at least partly out of the inner pipe  1002  or the outer pipe  1003  of the nozzle  1001 , it is possible to change the movablility of the part-section  1018 , in particular the frequency of the vibration of the part-section  1018  of the inlay  1013 . By way of the aforementioned measures, the symmetry and the droplet size of the spray is not influenced by deposits of the substance to be sprayed, during the manufacturing and/or spraying process, so that an undesirable spray drying and/or a local over-humidification and agglomeration does not occur. 
     The preferred nozzle  1001  with a volume of the device  1003  which is enlarged in comparison to the open position according to  FIG. 13  is represented in  FIG. 14 . For this, the pressurised air ring which is preferably used as a device  1033  is inflated with a fluid, in particular with a gas, preferably pressurised air or the like. The device  1033  is connected to a supply container which is not shown via a conduit which is likewise not shown and via which the device  1033  can be filled or emptied for example by way of a control device and/or closed-loop control device, which is not represented, so that the device  1033  changes its volume from a first volume in the open position according to  FIG. 13  to a second volume in the closure position according to  FIG. 14  and vice versa. 
     In the present embodiment example, the conduit  1032 , in particular the part-sections  1017  and  1018  which are arranged in the nozzle mouthpiece  1006 , as well as the annular gap  1008  are sealed off by way of the enlarged volume of the device  1033 . The conduit  1032 , here the part-sections  1018  are pressed together and the exit opening  1009  additionally closed due to the enlarged volume, so that a fluid can flow neither through the fluid channel  1005  nor through the annular gap  1008 . By way of this, for example in the case of the filling of a granulator, a coater, in particular a drum coater, or a fluidisation apparatus, one succeeds in no pellets or particles being able to penetrate into the exits openings  1007 ,  1009  of the nozzle  1001  and therefore blocking these already before the beginning of the manufacturing process. Further developments of the preferred nozzle  1001  which comprises a device  1033  which is changeable in its volume are conceivable. For example, there is the possibility of the nozzle  1001  comprising several devices  1033 , in particular two devices  1003 . Preferably, these are separated from one another by devices such as plates or the like, so that these can be operated independently of one another. Advantageously, the nozzle  1001  comprises a first device  1033  for the closure of the annular gap  1008  and a second device  1033  for the closure of the fluid channel  1005 . Hereby, the two devices  1033  are preferably to be separated by way of a plate or the like which functions as a separating wall, so that the volume change of a first device  1033  closes or opens the fluid channel  1005  and the volume change of a second device  1033  closes or opens the annular gap  1008 , without a volume change of the one device  1033  influencing the other device  1033 . By way of this, it is possible to provide an infinite adjustment of the volume flow with a through-flow of 0% and 100% for the atomisation gas as well as for the substance to be sprayed, wherein the adjustment of the volume flows can be effected independently of one another or in a manner depending on one another. 
     On using at least two devices  1033 , it is to be noted that the substance to be sprayed, in particular the liquid cannot exit out of the nozzle  1001  in a non-atomised manner, since otherwise a product rejection can occur, for example by way of agglomerated tablets. For this, it is to be ensured that at the beginning of each spraying procedure, it is firstly the gas, in particular the atomisation gas which flows through the annular gap  1008  and thus out of the nozzle  1001  and subsequently the substance to be sprayed, in particular the liquid. On completing the spraying procedure, the feed of the substance to be sprayed is firstly to be stopped and subsequently that of the gas. A closed-loop control or control device can accomplish this. By way of this, it is ensured at all times that the substance to be sprayed is always atomised given a spraying procedure and that no substance to be spayed drips out of the nozzle possibly onto material to be treated (coated), at the end of each spraying procedure. 
     It is always to be ensured than on bringing the device  1033  from the one closure position of the inner pipe  1002  into the at least one open position of the inner pipe  1002 , the gas which flows through the annular gap  1008  begins to flow through the annular gap at least simultaneously with the bringing of the device  1003  from the one closure position of the inner pipe  1002  into the at least one open position of the inner pipe  1002 . It is further advantageous that on bringing the device  1033  from the at least one open position of the inner pipe  1002  into the one closure position of the inner pipe  1002 , the gas which flows through the annular gap  1008  stops flowing through the annular gap  1008  at the earliest simultaneously on bringing the device  1033  from the at least one open position of the inner pipe  1002  into the one closure position of the inner pipe  1002 . 
     Advantageously, on starting up or ending the spraying procedure, by way of this method it is ensured that no exit of the substance to be sprayed occurs at the nozzle mouth, which is to say at the exit openings  1007 ,  1009  of the inner pipe  1002  and the outer pipe  1003 , without this substance being atomised directly by the gas which flows through the annular gap  1008 . An atomisation of the substance to be sprayed is therefore always ensured by the method. By way of this, on the one hand deposits on the nozzle mouth for example given the drying of the substance to be sprayed which has exited too early and on the other hand an agglomeration of particles to be sprayed on account of the non-atomised substance to be sprayed do not occur. 
       FIG. 15  represents a schematic construction of a first method for monitoring the nozzle mouthpiece  106  of a first embodiment of the preferred nozzle  101 . The nozzle  101  corresponds to that of the description of  FIGS. 2 to 4 . All other preferred embodiments of the nozzle  101 ,  301 ,  401 ,  501 ,  601 ,  701 ,  801 ,  901  and  1001  as well as further nozzles according to the invention can be monitored by this method. The nozzle  101  comprises an inner pipe  102  and an outer pipe  103  as well as an inlay  113  which is arranged on the inner pipe  118 , wherein the part-section  118  projects at least partly out of the exit opening  107  of the preferred nozzle  101  into an exit region  112 . 
     The monitoring of the nozzle mouthpiece with regard to deposits by way of the sensor  134  in the embodiment example of  FIG. 15  is effected by way of a sensor  134  which is arranged outside the nozzle. 
     Furthermore, the construction for the first method comprises a sensor  134 , in particular an optical sensor, very particularly preferably an imaging sensor, for example a camera or an ultrasound sensor, or a sensor which detects a physical measuring variable, for example a pressure sensor, very particularly preferably a differential pressure sensor. The sensor  134  detects the nozzle  101 , in particular the nozzle mouthpiece  106 , very particularly preferably the exit openings  107 ,  109  of the inner pipe  102  and/or of the outer pipe  103  in the exit region  112  of the nozzle  101 . The sensor  134  is sampled at a defined, adjustable rate. The sensor  134  is connected to a control unit  135 , in particular to a data-processing computer, for example an industrial PC or to be embedded PC or the like. The data which is detected by the sensor  134  is transmitted to the control unit  135 . The control unit  135  evaluates the data of the sensor  134 . The control unit  135  therefore determines, for example by way of an algorithm or the like, whether deposits form or have formed on the nozzle  101 , in particular the nozzle mouthpiece  106 , very particularly preferably the exit openings  107 ,  109  in the exit region  112  of the nozzle  101 . Such deposits compromise the quality of the spray, in particular the symmetry and/or the droplet size during the manufacturing and/or spraying process. 
     As soon as a certain stored limit values has been exceeded, for example due to deposits, by which means the symmetry and droplet size of the spray is compromised during the manufacturing and/or spraying process, the control unit  135  transmits a signal to be device  136 . In the embodiment example of  FIG. 15 , the device  136  is designed as a vibration device and is connected to the nozzle  101 . The device  136  brings the nozzle  101  into vibration in a manner such that the deposits on the nozzle  101  detach. As soon as the deposits are no longer present on the nozzle  101 , in particular on the nozzle mouthpiece  106 , very particularly preferably at the exit openings  107 ,  109  in the exit region  112  of the nozzle  101 , the respective signal is detected by the sensor  133  and transmitted to the control unit  135  which subsequently transfers a signal to the device  136 , said signal switching off the device  136 . This procedure is repeated over the complete manufacturing and/or spraying process as often as is necessary. The continuous monitoring of the preferred nozzle  101  which is carried out by the sensor  134  is preferably effected as an inline, atline or online measurement. For example, an ultrasound sensor detects the actual shape and the current dimensions of the preferred nozzle  101  (actual values). This data is subsequently used in the control unit  135  for assessing the spray quality and is compared to the initial data (setpoint) of the preferred nozzle  101 . Preferably, given too large a difference between the actual value and the setpoint, a signal is transmitted from the control unit  135  to the device  136  and the necessary measures (vibration) are started. Hereby, the device  136  which is designed as a vibration unit is connected to the nozzle  101  and on receiving a signal from the control unit  135  brings the nozzle into a vibration, so that the deposits at the nozzle mouthpiece  106  detach. The incorporation of the aforementioned steps into the manufacturing and/or spraying process permits the automatic monitoring of the spray quality over the entire duration of the manufacturing and/or spray process. 
     The monitoring of the nozzle mouthpiece  106  by the sensor  134  with regard to deposits is effected by a sensor  134  which is arranged within the nozzle  101  in the embodiment example of  FIG. 16 . Such an arrangement is sometimes useful, in particular in the case of constructionally restrictive conditions, for example given drum coaters or the like which have a small volume. 
     A second schematic construction of a method for monitoring the nozzle  101 , in particular the nozzle mouthpiece  106 , very particularly preferably the exit openings  107 ,  109  in the exit region  112  of a first embodiment of the preferred nozzle  101  is shown in  FIG. 16 . The pressure conditions of the original nozzle shape in the exit region  112 , i.e., without deposits or caking, correspond to the setpoint on pressure measurement. Hereby, a pressure sensor  134  is arranged in each case in the fluid channel  105  and in the annular gap  108 . The method preferably comprises several sensors  134 , in particular sensors  134  which operate independently of one another. By way of the several sensors  134 , it is possible to detect deposits on the nozzle mouthpiece  106  of the nozzle  134  which negatively influence the symmetry and the droplet size, to an improved extent, so that the most suitable measure for detaching the deposits, for example vibration or pulse, can be initiated. 
     The two sensors  134  are sampled at a certain adjustable rate, or at a certain cycle. Should deposits or agglomerations occur at the nozzle  101 , in particular at the nozzle mouthpiece  106 , very particularly preferably at the exit openings  107 ,  109  in the exit region  112 , then the pressure in the fluid channel  105  and/or the annular gap  108  increases (actual value). 
     This pressure increase is detected by the sensor  134  and is transferred to a control unit  135 . For example, the mass flow and thus also the volume flow of the substance to be sprayed and/or of the atomisation gas can be computed by way of the detected physical measured variable, here for example the absolute pressure. The pressure which is detected with measurement technology at the sensors  134  provides information of the deposits on the nozzle mouth piece  106 . Deposits b on the nozzle mouthpiece  106  lead to a pressure increase in front of the exit openings  107 ,  109  in the fluid channel  105  or annular gap  108  and thus to a larger flow speed of the substance to be sprayed and/or of the gas, so that given a suitable specification of thresholds values (setpoint) or tolerance ranges (for example ±10% deviation) and their exceeding or falling-short, the control unit  135  can initiate suitable counter measures for removing the deposits by way of transmitting a signal to the device  136 . 
     On monitoring, a continuous comparison between the actual value and the setpoint takes place by the control unit  135 . 
     As soon the exceeding or falling-short of a certain limit value (setpoint) is registered by the control unit  135 , the control unit  135  transmits a corresponding signal to a device  136 . In the embodiment example of  FIG. 16 , the device  136  is designed as a pulsation device. This is realised for example by closed-loop control valves on the corresponding feed conduits of the fluids. The device  136  generates a pulsating flow of the substance which is to be sprayed and/or of the gas, in particular the atomisation gas, represented by the two diagrams in  FIG. 16 . Preferably, the gas flow is pulsed only for a short while. If the pressure subsequently exceeds or falls short of the limit value again, then the manufacturing and spraying process is continued. If the limit value continues to be exceeded or fallen short of, then a renewed pulse is produced. The imparted pulse can have different frequencies, in particular between 1 Hz and 1500 Hz, preferably between 25 Hz and 250 Hz. By way of this, the deposits on the mouthpiece  106  in the region of the exit openings  107 ,  109  of the inner and outer pipe  102 ,  103  can be detached and removed to an improved extent. This procedure is repeated unit the deposits or agglomerations at the nozzle  101  are removed, so that the desired spray quality is always ensured. 
     The monitoring of the droplet size of the spray during the manufacturing and/or spraying process, for example by way of a laser measuring method, forms a third method. Given deviations of the actual value from the setpoint of the droplet size, i.e., given a non-optimal droplet size, the measures which are to be made generally correspond to the measures of the first and second method according to  FIG. 15  or  FIG. 16 .