WO2007072235A1

WO2007072235A1 - Continuous granulator and a method of continuous granulation of powder material

Info

Publication number: WO2007072235A1
Application number: PCT/IB2006/053905
Authority: WO
Inventors: Michel Simon Waldron
Original assignee: Collette Nv
Priority date: 2005-12-21
Filing date: 2006-10-24
Publication date: 2007-06-28

Abstract

A continuous granulator (1) comprises a longitudinal granulation cham ber (2) having a first end (7) with an inlet (8) for powder material and a binder feed port (15) and a second end (19) with an outlet (20) for granulated product. At least one rotary shaft (3, 4) provided with at least one granulating element (5, 6) is arranged in the granulation chamber (2). The outlet (20) is displaceable in relation to the at least one rotary shaft (3, 4) in the longitudinal direction of the rotary shaft.

Description

Continuous granulator and a method of continuous granulation of powder material

The present invention relates to a continuous granulator com- prising a longitudinal granulation chamber having a first end with an inlet for powder material and a binder feed port and a second end with an outlet for granulated product, at least one rotary shaft provided with at least one granulating element being arranged in the granulation chamber. Danish patent application no. PA 2005 00558 describes a continuous granulator comprising two parallel rotary shafts provided with granulating elements, whereby the shafts are arranged vertically or inclined in a longitudinal granulation chamber. Because the powder material advances through the granulation chamber substantially by means of gravity, the amount of work performed on the material depends very much on the feed rate of powder material in relation to the rotational speed of the shafts. Thereby, the character of the resulting product, for instance the density and particle size of the granules, may be controlled to a large degree by varying the feed rate at the inlet. Furthermore, the angle that the shafts form with the vertical may be varied, and thereby the transport speed of the material through the apparatus varies, whereby the amount of granulation work conveyed to the material is varied. Consequently, the quality of the granulated product may be controlled in this way. US 4,416,606 describes a granulator for preparing granules from a powdery material by agglomerating it through a kneading zone and breaking it into granules in a breaking zone. The granulator comprises a horizontally arranged housing in which two shafts are enclosed in parallel configuration. The shafts extend from an upwardly open inlet hopper at a first end of the housing to a downwardly open discharge port at a second end of the housing. The inside of the housing is composed of, in succession, a feeding zone at the first end, the kneading zone and the breaking zone at the second end. In the feeding zone, the shafts are provided with forwardly conveying screw blades. The kneading zone is composed of an upstream section, in which the shafts are provided with both forwardly and backwardly conveying screw blades, and a downstream section, in which the shafts are provided with backwardly conveying screw blades. Following the kneading zone, the breaking zone is arranged, in which the shafts have no screw blades, but are provided with a plurality of small projections on their periphery. In the downstream section of the kneading zone, a part of the top wall of the housing is replaced by a cover that is arranged slightly movable in the upward and downward direction, whereby the kneading force may be var- ied.

US 6,499,984 discloses a so-called twin screw wet granulator- chopper comprising a housing containing conveying elements, mixing elements and chopping elements. The outlet of the housing has the form of a non-extruding opening. For mixing and chopping functions, different designs are indicated, such as kneading discs, combing mixers, gear mixers, pin mixers and calender gap mixers. The conveying and mixing elements may further include reverse threads, kneading elements and/or gear elements.

WO 2004/047974 Al discloses an apparatus for continuous wet granulation of powder material, comprising a housing enclosing two parallel screws forming a first transport zone, a first agglomeration zone comprising mixing paddles, an intermediate transport zone, a second agglomeration zone comprising mixing paddles, and a second transport zone. The outlet has the form of a free flow discharge at an end of the two parallel screws. It is mentioned that the material agglomerated in the agglomeration zone breaks up into granules in the second transport zone. The condition of the resulting granules depends, to a large extent, on the exact configuration of the two parallel screws. Consequently, the possibilities of controlling the product quality are limited to controlling the rotational speed of the screws and the feeding conditions of the powder material.

SU 1724349 relates to a horizontally arranged continuous granulator having a single shaft provided with radial rods forming crushing and granulating zones. The reciprocating movement of the rotating shaft in longitudinal direction varies the paths of the outer ends of the rods radially mounted on the shaft and travelling near the inner wall of the granulation chamber thus preventing a build-up of material on the wall. Thereby, the output is increased as a result of the fact that the shaft can reciprocate longitudinally.

The object of the present invention is to provide a continuous granulator having flexible capabilities of controlling the quality of the granulated product.

In view of this object, the outlet position is adjustable in relation to the at least one rotary shaft in the longitudinal direction of the rotary shaft in order to vary the amount of work performed on the product in the granulation chamber.

In this way, the amount of work performed on the product in the granulation chamber may be varied continuously according to a de- sired product quality, and according to measured variables of the produced product, whereby the quality of the resulting granulated product may be controlled very accurately. If the position of the outlet relative to the at least one rotary shaft is displaced in the direction of the inlet, the amount of work being performed on the product may be reduced, be- cause a smaller part of the at least one granulating element or less of the granulation elements may take part in the working of the product. Correspondingly, if the position of the outlet relative to the at least one rotary shaft is displaced in the direction away from the inlet, the amount of work being performed on the product may be increased. Of course, the position of the outlet may alternatively be adjusted manually on a regular basis or when necessary, for instance before the production of granules is started.

In an advantageous embodiment in terms of structure and operation, the at least one rotary shaft is displaceable in its longitudinal di- rection in the granulation chamber. Thereby, the outlet and the granulation chamber may be stationary.

In an advantageous embodiment in terms of structure and operation, the outlet has the form of a single opening in a side wall of the granulation chamber. In an advantageous embodiment in terms of structure and operation, the outlet opens out through a side wall of the granulation chamber and is arranged displaceably in relation to the granulation chamber in the longitudinal direction of the at least one rotary shaft. In an advantageous embodiment in terms of structure and operation, the outlet has the form of a single opening that has a cross- sectional dimension that is at least 1/5, preferably at least 1/3, and most preferred at least 1/2, of the largest inner cross-sectional dimension of the granulation chamber. In an advantageous embodiment, the outlet opens out into an outlet channel extending from the granulation chamber in a transverse direction of the least one rotary shaft, and a gas inlet channel opens into the granulation chamber opposite the outlet channel. Thereby, flakes may by means of the gas stream or jet be broken off from the material worked by the granulating element or elements in the form of granules at the exact position, where the outlet is located in relation to the at least one rotary shaft. Consequently, the amount of work conveyed to the material worked may be controlled very precisely.

In an advantageous embodiment in terms of structure and op- eration, the at least one rotary shaft is arranged substantially vertically, the outlet channel is directed away form the granulation chamber in a downward direction, and the gas inlet channel is substantially parallel with the outlet channel. Thereby, the powder material will advance through the granulation chamber substantially by means of gravity, and the amount of work performed on the material depends very much on the feed rate of powder material to the inlet of the apparatus in relation to the rotational speed of the shafts. Thereby, the character of the resulting product, in other words for instance the density and particle size of the granules, may be further precisely controlled by varying the feed rate at the inlet.

In an advantageous embodiment in terms of structure and operation, the at least one rotary shaft comprises a first section provided with at least one granulating element and a second section that has no granulating elements, and the at least one rotary shaft is displaceable in the granulating chamber between a retracted position, in which the first section of the rotary shaft is located substantially outside a gas transport zone formed between the gas inlet channel and the outlet channel, and an extended position, in which the second section of the rotary shaft is located substantially outside said gas transport zone. Thereby, by aiming at a standard production condition at a position of the at least one rotary shaft corresponding substantially to the retracted position, it may be an advantage that said gas transport zone has a large cross-section due to the fact that the granulating elements are located substantially outside said gas transport zone, so that the produced granules are transported efficiently away from the granulating element or elements.

In an embodiment, each granulating element on a shaft comprises at least one lobe having limited extent in the circumferential direction of the shaft and interleaving with a lobe of a granulating element on another shaft, a plurality of such separate granulating elements are distributed on the shaft, and successive granulating elements on a shaft are mutually angled. This configuration may further enhance the tendency that the work performed on the material depends very much on the feed rate of powder material to the inlet of the apparatus in relation to the rotational speed of the shafts, so that the character of the resulting product may be further precisely controlled by varying the feed rate and the rotational speed.

In an embodiment, successive granulating elements on a shaft abut each other. Thereby, a more compact apparatus, in other words a shorter granulation chamber, may be achieved. Furthermore, it is ensured that the entire inner wall of the granulation chamber is swept by the granulating elements, thereby preventing build-up on the wall.

In an embodiment, each granulating element has opposed end faces that are perpendicular to the direction of the shafts and lateral faces that are parallel to the direction of the shafts. In this way, the granulating elements are easy to manufacture. Furthermore, it is ensured that the rotation of the granulating elements does not contribute substantially to the transportation of the powder material in the longitudinal direction of the granulation chamber. Thereby, it is easier to con- trol the material transport through the apparatus by means of the feed rate of the powder material, the tilt angle of the at least one shaft and the position of the outlet in relation to said shaft.

In an embodiment, each granulating element is disc-shaped. By providing the granulating elements in the form of disc-shaped elements, a large number of granulating elements may be applied, thereby giving great flexibility in terms of the possible number of different configurations that may be achieved by arranging the granulating elements in relation to each other, for instance by varying the mutual angle between successive granulating elements on a shaft.

In an embodiment, the first section of the at least one rotary shaft comprises one granulating element in the form of a continuous screw blade. Thereby, it is ensured that the entire inner wall of the granulation chamber is swept by the granulating elements, thereby pre- venting build-up on the wall.

In an embodiment, there is provided a processing unit or computer adapted to control the position of the at least one rotary shaft in relation to the outlet, and data from instruments for the measurement of parameters such as moisture content, density, active component, parti- cle size and shape of the granules are fed into the processing unit or computer. Thereby the performance of the apparatus may automatically be controlled accurately.

The invention further relates to a method of continuous granulation of powder material, whereby material and binder are fed through an inlet into a first end of a longitudinal granulation chamber, the material is granulated by means of at least one granulating element provided on at least one rotating shaft extending in the longitudinal direction of the granulation chamber, and granulated product is discharged through an outlet from a second end of the granulation chamber. The method is characterized by that the position of the outlet in relation to the at least one rotary shaft is adjusted in the longitudinal direction of the rotary shaft according to properties of the granulated product such as moisture content, density, active component, and particle size and shape of the produced granules. Thereby, the above- mentioned advantages may be obtained.

In an embodiment, the granules are broken off from the material worked by the at least one granulating element by means of a gas stream or jet entering through an inlet channel in a side wall of the granulation chamber, and the granules leave the granulation chamber through an outlet channel extending from the granulation chamber substantially parallel to and opposite the inlet channel. Thereby, the above- mentioned advantages may be obtained.

In an embodiment, the position of the outlet in relation to the at least one rotary shaft is adjusted according to desired properties of the granulated product, before the production of granules is started. Thereby, the above-mentioned advantages may be obtained.

In an embodiment, the position of the outlet in relation to the at least one rotary shaft is adjusted during the production of granules ac- cording to measured properties of the produced granules. Thereby, the above-mentioned advantages may be obtained.

In an embodiment, the position of the outlet in relation to the at least one rotary shaft is adjusted by means of a processing unit or computer on the basis of data supplied from instruments measuring parame- ters such as moisture content, density, active component, and particle size and shape of the granules. Thereby, the above-mentioned advantages may be obtained.

In an embodiment, the position of the outlet in relation to the at least one rotary shaft is adjusted by displacement of the at least one ro- tary shaft in its longitudinal direction in the granulation chamber. Thereby, the above-mentioned advantages may be obtained.

The invention will now be explained in more detail below by means of examples of embodiments with reference to the very schematic drawing, in which Fig. 1 shows an axial section through a continuous granulator according to the invention, in a first position of the rotary shafts,

Fig. 2 shows an axial section through the continuous granulator in Fig. 1, in a second position of the rotary shafts,

Fig. 3 shows an axial section through another embodiment of the continuous granulator according to the invention,

Fig. 4 shows an axial section through the granulation chamber of another embodiment of the continuous granulator according to the invention, and Fig. 5 shows an embodiment of successive granulating elements of the continuous granulator in Fig. 1.

Fig. 1 shows a longitudinal cross-section through a continuous granulator 1 according to the invention, for granulation of powder material, for instance of a pharmaceutical product. The granulator 1 com- prises a longitudinal granulation chamber 2 in which two parallel rotary shafts 3, 4 are arranged vertically. On each shaft 3, 4 is arranged a plurality of granulating elements 5, 6.

Fig. 5 shows an embodiment of the granulating elements 5, 6, whereby the granulating elements, seen in the axial direction, have a contour composed of two circular sections. Said circular sections are formed by opposed lateral faces 25, 26 that are parallel to the direction of the shafts 3, 4. In this embodiment, furthermore the granulating elements 5, 6 have opposed end faces 27 that are perpendicular to the direction of the shafts 3, 4. Two successive granulating elements 5, 5', 6, 6' on each shaft 3, 4, respectively, are shown in an embodiment of the granulator 1, whereby successive granulating elements are mutually angled by 90 degrees, whereby the capacity of the apparatus will be relatively low, and the amount of work performed on the powder material will be relatively high, resulting in relatively large granules. If the angle between successive granulating elements 5, 5', 6, 6' is, for instance, 30 degrees, a higher capacity of the apparatus will be obtained, and the amount of work performed on the powder material will be smaller, resulting in relatively smaller granules.

At a first, upper end 7 of the granulation chamber 2 is arranged an inlet 8 in the form of a downwardly tapering funnel 9 through which powder material may fall by means of gravity into the granulation chamber 2 at the first end 7. In order to ensure a regular supply of the powder material to the granulation chamber, a first rotary dividing wall 10 is arranged in the funnel 9 on a vertical spindle 11 driven by a drive motor 12. Inside the funnel 9, at its bottom, an upwardly tapering cone 13 is arranged centrally in the funnel 9 just above the first end 7 of the granulation chamber 2. The cone 13 has a lower diameter slightly larger than the distance between the shafts 3, 4 and slightly smaller than the largest inner cross-sectional dimension of the granulation chamber 2. In this way, the cone 13 covers the upper ends of the shafts 3, 4 and ensures that the powder material is fed into the granulation chamber 2 at the periphery. The rotary dividing wall 10 in the funnel 9 has an upwardly tapering triangular cutout 14 corresponding to the cone 13. A binder feed port 15 is arranged through the wall of the granulation chamber 2 at the first end 7. A binder feed pump 16 is arranged immediately adjacent the granulation chamber 2 communicating directly with the binder feed port 15. Additional binder feed ports may be arranged at the first end 7 or along the granulation chamber. The binder feed pump 16 comprises a drive spindle 17 driven by a not shown motor and carrying one or more impellers 18 that are indicated schematic. The feed pump 16 may work in a well-known manner. The feed pump is independently supplied with liquid, solution, suspension or gas or any combination thereof. At a second, lower end 19 of the granulation chamber 2, an outlet 20 for granulated product is arranged in a peripheral wall 21 of the granulation chamber 2 and opens out into an outlet channel 22 that is downwardly inclined in a transverse direction of the rotary shafts 3, 4. Diametrically opposite the outlet 20 in relation to the granulation cham- ber 2, a transport gas inlet channel 23 is arranged in parallel with the outlet channel 22, whereby transport gas may be blown in the direction of the outlet 20 diametrically through the second end 19 of the granulation chamber 2, thereby carrying granulated product from the granulation chamber to the outlet 20. Thereby, a gas transport zone 24 is formed between the gas inlet channel 23 and the outlet channel 22.

It should be noted that the outlet 20 is non-extruding, so that no significant pressure gradient is present over the outlet during operation of the continuous granulator. Furthermore, the outlet 20 has the form of a single opening that has a cross-sectional dimension that is at least 1/5, preferably at least 1/3, and most preferred at least 1/2, of the largest inner cross-sectional dimension of the granulation chamber 2. Although the outlet is described as a single opening, it can be composed of more openings. The rotary shafts 3, 4 are journalled at each end in bearings 28,

29, 30, 31 and driven by means of a drive unit 32. The drive unit 32 comprises a not shown drive motor, such as an electric motor, and a not shown transmission driving the two shafts 3, 4 synchronously. The lower bearings 28, 29 carrying the lower ends of the shafts 3, 4 are arranged in a slider 33 that is arranged vertically displaceable in a lower part 34 of the granulation chamber 2. Correspondingly, the upper bearings 30, 31 are arranged vertically displaceable in the granulation chamber 2. The rotary shafts 3, 4 are by means of a linear actuator 35, such as a pneumatic actuator, displaceable between a retracted position shown in Fig. 1 and an extended position shown in Fig. 2. The rotary shafts 3, 4 may be arranged vertically displaceable in other suitable ways than shown in the figures.

The rotary shafts 3, 4 comprise a first upper section 36 provided with granulating elements 5, 6 and a second lower section 37 without granulating elements. In the retracted position shown in Fig. 1, the first section 36 of the rotary shafts is located substantially outside the gas transport zone 24 formed between the gas inlet channel 23 and the outlet channel 22, and in the extended position shown in Fig. 2, the second section 37 of the rotary shafts is located substantially outside said gas transport zone 24.

Apparently, in the retracted position shown in Fig. 1, the gas transport zone 24 has a larger free cross-sectional area than in the extended position shown in Fig. 2, and consequently a good transport effect is achieved for the transportation of granules away from the granu- lation chamber. Therefore, parameters such as feed rate of powder material to the inlet 8 and rotational speed of the shafts 3, 4 may be adjusted so that a good performance of the granulator is generally achieved approximately in the retracted position. Further regulation of the performance may then be obtained by displacing the shafts 3, 4 be- tween the retracted and the extended positions. In the extended position, the amount of work being performed on the product is reduced compared to in the retracted position, because less of the granulation elements 5, 6 take part in the working of the product. This is due to the fact that the granulation elements 5, 6 have to be surrounded by the wall of the granulation chamber 2 in order to perform a significant work on the product. The more work that is being performed on the product, the larger a size of the granules is obtained.

The vertical position of the rotary shafts 3, 4 as well as other parameters such as feed rate, rotational speed of the rotary shafts 3, 4, the performance of the feed pump 16, among other things, are controlled by means of a computer 38 on the basis of input values from the user and measured variables of the produced product.

Fig. 3 shows another embodiment of the continuous granulator according to the invention, whereby one single shaft in the form of a continuous screw spindle 39 is arranged horizontally in a cylindrical granulation chamber 40 having an upwardly open inlet funnel 41 and an axially directed outlet opening 42 at an end face of the cylindrical granulation chamber 40. By displacement of the screw spindle 39 in the longitudinal di- rection of the granulation chamber 40, a part of the screw spindle 39 may extend out from the outlet opening 42, so that a smaller part of the screw spindle 39 takes part in the working of the material, so that a different quality of product, for instance smaller particles, is obtained.

Fig. 4 shows an axial section through the granulation chamber 43 of another embodiment of the continuous granulator according to the invention. The embodiment corresponds to the embodiment shown in Fig. 3 apart from having a vertical rotary shaft 45, whereby, however, the outlet 44 is displaceable in relation to the rotary shaft 45 in the longitudinal direction of the rotary shaft by displacement of the outlet 44 itself in rela- tion to the stationary granulation chamber 43, as opposed to the granulator shown in Fig. 3, in which the rotary drive shaft 39 is displaceable in the granulation chamber 40.

In yet another embodiment, the granulating elements may be displaceably mounted on their rotary shaft, for instance by means of a spindle drive mechanism arranged integrated in the rotary shaft, so that the longitudinal position of the granulating elements in relation to the rotary shaft may be adjusted.

The skilled person will understand that the different embodi- ments described above can be combined in any suitable manner; for instance, the horizontally arranged granulator shown in Fig. 3 may be provided with an outlet that is displaceable in relation to the rotary shaft by displacement of the outlet itself in relation to the stationary granulation chamber, as it is the case for the vertically arranged granulator shown in Fig. 4. Furthermore, in the vertically arranged granulator shown in Figs. 1 and 2, the outlet may be displaceable in relation to the rotary shaft by displacement of the screw spindle in the longitudinal direction of the granulation chamber, whereby a part of the screw spindle may extend out from the outlet opening arranged at the end, in the same manner as it is the case for the embodiment shown in Fig. 4.

Claims

P A T E N T C L A I M S

1. A continuous granulator comprising a longitudinal granulation chamber having a first end with an inlet for powder material and a binder feed port and a second end with an outlet for granulated product, at least one rotary shaft provided with at least one granulating element being arranged in the granulation chamber, cha ra cterized in that the outlet position is adjustable in relation to the at least one rotary shaft in the longitudinal direction of the rotary shaft in order to vary the amount of work performed on the product in the granulation chamber.

2. A continuous granulator according to claim 1, cha ra cterized in that the at least one rotary shaft is displaceable in its longitudinal direction in the granulation chamber.

3. A continuous granulator according to claim 1 or 2, c h a r - a cterized in that the outlet has the form of a single opening in a side wall of the granulation chamber.

4. A continuous granulator according to claim 1 or 2, c h a r - a cterized in that the outlet opens out through a side wall of the granulation chamber and is arranged displaceably in relation to the granulation chamber in the longitudinal direction of the at least one ro- tary shaft.

5. A continuous granulator according to any one of the preceding claims, cha ra cte rized in that the outlet has the form of a single opening that has a cross-sectional dimension that is at least 1/5, preferably at least 1/3, and most preferred at least 1/2, of the largest inner cross-sectional dimension of the granulation chamber.

6. A continuous granulator according to any one of the preceding claims, cha ra cte rized in that the outlet opens out into an outlet channel extending from the granulation chamber in a transverse direction of the least one rotary shaft, and in that a gas inlet channel opens into the granulation chamber opposite the outlet channel.

7. A continuous granulator according to claim 6, cha ra cterized in that the at least one rotary shaft is arranged substantially vertically, in that the outlet channel is directed away form the granulation chamber in a downward direction, and in that the gas inlet channel is substantially parallel with the outlet channel.

8. A continuous granulator according to claim 6 or 7, c h a r - a cterized in that the at least one rotary shaft comprises a first section provided with at least one granulating element and a second sec- tion that has no granulating elements, and in that the at least one rotary shaft is displaceable in the granulating chamber between a retracted position, in which the first section of the rotary shaft is located substantially outside a gas transport zone formed between the gas inlet channel and the outlet channel, and an extended position, in which the second section of the rotary shaft is located substantially outside said gas transport zone.

9. A continuous granulator according to any one of the preceding claims, cha ra cterized in that each granulating element on a shaft comprises at least one lobe having limited extent in the circum- ferential direction of the shaft and interleaving with a lobe of a granulating element on another shaft, in that a plurality of such separate granulating elements are distributed on the shaft, and in that successive granulating elements on a shaft are mutually angled.

10. A continuous granulator according to any one of the preced- ing claims, cha ra cterized in that successive granulating elements on a shaft abut each other.

11. A continuous granulator according to any one of the preceding claims, cha ra cterized in that each granulating element has opposed end faces that are perpendicular to the direction of the shafts and lateral faces that are parallel to the direction of the shafts.

12. A continuous granulator according to any one of the preceding claims, cha ra cte rized in that each granulating element is disc-shaped.

13. A continuous granulator according to claim 8, cha ra c- t e r i z e d in that the first section of the at least one rotary shaft comprises one granulating element in the form of a continuous screw blade.

14. A continuous granulator according to any one of the preceding claims, cha ra cte rized in that there is provided a processing unit or computer adapted to control the position of the at least one rotary shaft in relation to the outlet, and in that data from instruments for the measurement of parameters such as moisture content, density, active component, particle size and shape of the granules are fed into the processing unit or computer.

15. A method of continuous granulation of powder material, whereby material and binder are fed through an inlet into a first end of a longitudinal granulation chamber, the material is granulated by means of at least one granulating element provided on at least one rotating shaft extending in the longitudinal direction of the granulation chamber, and granulated product is discharged through an outlet from a second end of the granulation chamber, c h a r a c t e r i z e d by that the position of the outlet in relation to the at least one rotary shaft is adjusted in the longitudinal direction of the rotary shaft according to properties of the granulated product such as moisture content, density, active component, and particle size and shape of the produced granules.

16. A method of continuous granulation of powder material according to claim 15, c h a r a c t e r i z e d by that the granules are broken off from the material worked by the at least one granulating element by means of a gas stream or jet entering through an inlet channel in a side wall of the granulation chamber, and by that the granules leave the granulation chamber through an outlet channel extending from the granulation chamber substantially parallel to and opposite the inlet channel.

17. A method of continuous granulation of powder material according to claim 15 or 16, c h a r a c t e r i z e d by that the position of the outlet in relation to the at least one rotary shaft is adjusted according to desired properties of the granulated product, before the production of granules is started.

18. A method of continuous granulation of powder material according to claim 15 or 16, c h a r a c t e r i z e d by that the position of the outlet in relation to the at least one rotary shaft is adjusted during the production of granules according to measured properties of the produced granules.

19. A method of continuous granulation of powder material according to any one of the claims 15 to 18, c h a r a c t e r i z e d by that the position of the outlet in relation to the at least one rotary shaft is adjusted by means of a processing unit or computer on the basis of data supplied from instruments measuring parameters such as moisture content, density, active component, and particle size and shape of the granules.

20. A method of continuous granulation of powder material according to any one of the claims 15 to 19, c h a r a c t e r i z e d by that the position of the outlet in relation to the at least one rotary shaft is adjusted by displacement of the at least one rotary shaft in its longitudinal direction in the granulation chamber.