DEVICE FOR CONTROLLING PELLETIZING APPARATUS FOR THE PRODUCTION OF POLYMER PELLETS

Abstract

A pelletizing apparatus includes a filter device connected with a melt feed, a granulator downstream of the filter device, particularly an underwater granulator, a water treatment device, and a control means for controlling the filter device, underwater granulator, and water treatment device and adapted to provide at least one control parameter. The apparatus includes at least one machine-readable and -writable identification means for storing and providing an item of component-specific information and being associated with a component in the flow path of the melt or the process water, and a reading device communicating with the control means to receive the component-specific information from the identification means, and a writing device to write the identification means with the component-specific information, the control means to adapt the control parameter based on the component-specific information to provide the component-specific information, and, based on the component-specific information, to execute a diagnostic process.

Claims

1. A device configured to be coupled in fluid-conducting relationship with a component of a pelletizing apparatus in a flow path of a polymer melt or process water, the device comprising: at least one identification means associated with the component of the pelletizing apparatus and configured to store and provide at least one item of component-specific information is stored; and a reading and writing device configured to (a) be in signal-conducting relationship to a control means for controlling the device and providing a control parameter for the device, (b) receive the component-specific information from the identification means, and (c) write and/or overwrite the identification means with the component-specific information, wherein the device is further configured to execute a diagnostic process based on the component-specific information.

2. The device of claim 1, wherein the control parameter is configured to be adapted in dependence on the component-specific information to thereby adapt operation of the component of the pelletizing apparatus.

3. The device of claim 1, wherein the device is a filter device configured to separate impurities from a polymer melt.

4. The device of claim 3, wherein the component is at least one filter element arranged in the flow path of the polymer melt and configured to filter the polymer melt, and the identification means is associated with the at least one filter element.

5. The device of claim 4, wherein the filter device is a sieve changer and the at least one filter element includes a first sieve and a second sieve.

6. The device of claim 5, wherein: in a normal operation of the filter device, both the first sieve and the second sieve are configured to filter the polymer melt; and in a cleaning operation of the filter device, only a selected one of the first sieve and the second sieve is configured to filter the polymer melt.

7. The device of claim 3, wherein the filter device comprises: a filter housing having a filter chamber, an inlet for introduction of the polymer melt into the filter chamber, an outlet for discharge of the polymer melt from the filter chamber, and a dirt outlet for discharge of the impurities from the filter housing; a filter element arranged in the filter chamber and through which the polymer melt is configured to pass, the filter element configured to retain the impurities of the polymer melt; and a cleaning device configured to clean the filter element of the impurities retained by the filter element.

8. The device of claim 7, wherein the cleaning device includes a cleaning head having at least one scraper body configured to detach the impurities from the filter element.

9. The device of claim 8, wherein the cleaning head and the filter element are moveable relative to each other and configured to be brought into contact with each other.

10. The device of claim 9, wherein the at least one scraper body is coupled to an adjusting device configured to press the scraper body against a surface of the filter element.

11. The device of claim 1, wherein the device is a granulator configured to produce polymer pellets.

12. The device of claim 11, wherein the granulator is an underwater granulator.

13. The device of claim 11, wherein the component is an apertured plate arranged in the flow path of the polymer melt and configured to produce polymer strands, and the identification means is associated with the apertured plate.

14. The device of claim 11, wherein the component is a blade head configured to sever the polymer strands into individual pellets, and the identification means is associated with the blade head.

15. The device of claim 11, wherein the granulator comprises: an apertured plate arranged in the flow path of the polymer melt and configured to produce polymer strands; and a blade head configured to sever the polymer strands into individual pellets.

16. The device of claim 1, wherein the device is a water treatment device configured to clean the process water.

17. The device of claim 16, wherein the component is at least one water filter configured to filter the process water, and the identification means is associated with the at least one water filter.

18. The device of claim 17, wherein the at least one water filter is a filter belt configured to be cleaned by a scraper.

19. The device of claim 17, wherein the at least one water filter includes a first water filter in the form of a sieve cassette and a second water filter in the form of a filter belt.

20. The device of claim 1, wherein the device is configured to execute the diagnostic to thereby monitoring operation of the device and operation of the pelletizing apparatus as a whole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0194] Preferred embodiments of the invention are described hereinafter with reference to the accompanying Figures in which:

[0195] FIG. 1 shows a diagrammatic view of a pelletizing apparatus,

[0196] FIG. 2 shows a filter device for a pelletizing apparatus according to FIG. 1 in a first preferred embodiment,

[0197] FIG. 3 shows a filter device for a pelletizing apparatus according to FIG. 2 in a second preferred embodiment,

[0198] FIG. 4 shows a sectional view of the filter device of FIG. 3,

[0199] FIG. 5 shows a filter element for the filter device of FIG. 3,

[0200] FIG. 6 shows an underwater granulator for a pelletizing apparatus according to FIG. 1,

[0201] FIG. 7 shows a perspective partly sectional view of an underwater granulator as shown in FIG. 6,

[0202] FIG. 8 shows a sectional view of a portion of an underwater granulator as shown in FIG. 6,

[0203] FIG. 9 shows a housing of the underwater granulator as shown in FIG. 6,

[0204] FIG. 10 shows a start-up valve for an underwater granulator as shown in FIG. 6,

[0205] FIG. 11a shows an apertured plate for an underwater granulator as shown in FIG. 6 in a first perspective view according to a first preferred embodiment,

[0206] FIG. 11b shows the apertured plate of FIG. 11a in a second perspective view,

[0207] FIG. 12a shows an apertured plate for an underwater granulator as shown in FIG. 6 in a second preferred embodiment as a perspective view,

[0208] FIG. 12b shows the apertured plate of FIG. 12a in a second perspective view,

[0209] FIG. 13 shows a cutting plate for an apertured plate as shown in FIGS. 12a and 12b in a perspective view,

[0210] FIG. 14a shows a blade head for an underwater granulator as shown in FIG. 6 in a first perspective view,

[0211] FIG. 14b shows the blade head of FIG. 14a in a second perspective view,

[0212] FIG. 15a shows an entrainment member for a blade head in a first perspective view,

[0213] FIG. 15b shows the blade head of FIG. 15a in a second perspective view,

[0214] FIG. 16 shows a water treatment device for a pelletizing apparatus as shown in FIG. 1 in a perspective view,

[0215] FIG. 17 shows a portion of the water treatment device of FIG. 16 in a perspective view,

[0216] FIG. 18 shows a sieve cassette for a water treatment device as shown in FIGS. 16 and 17, and

[0217] FIG. 19 shows a filter (belt) for a water treatment device as shown in FIGS. 16 and 17 in a perspective view.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0218] FIG. 1 shows a pelletizing apparatus 1 having a filter device 5 which can be connected in fluid-conducting relationship to a melt feed 3.

[0219] In this embodiment the melt feed 3 is a component part of a melting apparatus 3.

[0220] The filter device 5 is adapted to filter the polymer which is liquefied by the melting apparatus 3 and in particular to remove contaminating impurities and residues of filling material from the molten polymers.

[0221] The filter device 5 is connected in fluid-conducting relationship to a downstream-disposed underwater granulator 7. The underwater granulator 7 is adapted to divide the filtered polymer melt provided by the filter device 5 into individual polymer strands and sever them into individual strand portions which are then removed in the form of pellets or granules.

[0222] The pellets can preferably be fed to a downstream-connected drying device 9 which can preferably also be part of the pelletizing apparatus 1 and which is adapted to reduce the water content in the pellets and to promote crystallization of the preferably thermoplastic polymer pellets, in particular by the action of temperature.

[0223] The pelletizing apparatus 1 further includes a water treatment device 11. The excess process water from the drying device 9 and/or from the underwater granulator 7 is then cleaned of residues of the polymer melt by the water treatment device 11 and prepared again for the process, preferably the underwater granulator 7.

[0224] The pelletizing apparatus 1 further includes a control means 13 adapted to control the melting apparatus 3 and/or the filter device 5 and/or the underwater granulator 7 and/or the water treatment device 11 and to provide at least one control parameter.

[0225] The control parameters in that case can be for example a rotary speed, a speed, a temperature, a conveyor volume flow, a pressure or a power output.

[0226] In addition, the pelletizing apparatus 1 includes a reading device 15 adapted to read out component-specific information from an identification means (not shown) which is associated with a component in the flow path of the polymer melt and/or the process water.

[0227] The pelletizing apparatus 1 further includes a writing device 17 adapted to write and/or overwrite the identification means (not shown) with the component-specific information.

[0228] FIG. 2 shows the filter device 5 which can be connected in fluid-conducting relationship to the melting apparatus 3 (see FIG. 1).

[0229] In the embodiment of FIG. 2 the filter device 5 is in the form of a sieve changer. The sieve changer 5 has a filter housing 23 in which two filter elements 19a, b, so-called sieve carriers having a sieve, are displaceably arranged. In that case the filter housing 23 has a housing inlet 27 and a housing outlet 25 through which a flow passage is created.

[0230] The underwater granulator 7 (see FIG. 1) can be connected in fluid-conducting relationship to the filter housing 23 of the sieve changer 5, wherein the polymer melts which is liquefied by the melting apparatus 3 is firstly passed into the housing inlet 27 of the filter housing 23, then through the filter element 19 and finally through the housing outlet 25.

[0231] When the sieve changer 5, as in the present case, has two sieve carriers each having a respective sieve 19a, b a contaminated sieve can be moved out of the flow passage. In that position the contaminated sieve is in a change position in which it is accessible and can be cleaned or can be replaced by an unused or previously cleaned sieve. The other sieve can then be moved into the change position and replaced.

[0232] Fixed to the sieve carriers having the sieves 19a, b is an identification means 21 which stores and provides component-specific information relating to the degree of filter fineness and/or the maximum service life and/or the structural configuration and/or article number and/or drawing number and/or serial number and/or material identification of the sieves 19a,b. The foregoing list is only given by way of example and is not to be deemed definitive. The component-specific information stored on the identification means 21 can be read by the reading device magnetically, by way of infrared or radio.

[0233] The sieve changer 5 is connected in signal-conducting relationship to a control means (not shown). The control means is adapted to provide at least one control parameter for controlling the sieve changer 5, in which case, in this embodiment, the control parameter is a conveyor volume flow or a pressure.

[0234] The control means is connected to a combined reading and writing device 15, 17 adapted to receive and/or overwrite or supplement the component-specific information from the identification means 21.

[0235] The control means is adapted to adapt at least one of the above-mentioned control parameters in dependence on the component-specific information, to provide the component-specific information and in particular based on the component-specific information to perform a diagnostic process and/or produce a warning message.

[0236] Such a warning message or the result of the diagnostic process can include for example a recommendation to carry out a cleaning operation and/or a maintenance operation and/or replacement of the component provided with the identification means and/or a cooperating component of the filter device 5.

[0237] FIG. 3 shows a perspective view of a filter device 5 for the removal of dirt particles from a polymer melt, having a filter housing 23 with a filter chamber.

[0238] As the sectional view of the filter device 5 in FIG. 4 in particular shows the filter housing 23 has a housing inlet (not shown in greater detail) for introducing the polymer melt to be cleaned into the filter chamber and an outlet (not shown) for passing the cleaned polymer melt out of the filter chamber. In addition, the filter housing 23 has a dirt outlet 37 through which dirt particles filtered out of the polymer melt can be discharged from the filter housing 23. Arranged in the filter housing 23 or the filter chamber is a filter element 19 for filtering dirt particles out of the polymer melt, through which the polymer melt can be passed.

[0239] The filter element 19 has a dirt side 28 at which the dirt particles accumulate or at which the dirt particles are retained and a clean side 29 at which the cleaned polymer melt flows away.

[0240] The filter device 5 also has a cleaning device 29 (not shown in greater detail) for cleaning the filter element 19 of dirt particles retained on the dirt side 28 from the polymer melt. The cleaning device 29 preferably includes a cleaning head having a plurality of scraper bodies for detaching dirt particles which have collected at the filter element 19 and preferably passing the dirt particles in the direction of the dirt outlet 37.

[0241] The cleaning device 29 includes a shaft 31 operatively connected to a drive (not shown).

[0242] As FIG. 4 further shows disposed in the region of the dirt outlet 37 is a dirt discharge screw 35 which is associated with the cleaning device 29 and is coupled to the shaft 31. The dirt particles removed by the cleaning device 29 at the filter element 19 are discharged or removed from the filter chamber by means of the dirt discharge screw 35.

[0243] Fixed to the filter element 19 is an identification means 21 which stores and provides component-specific information relating to the degree of filter fineness and/or the maximum service life and/or the structural configuration and/or article number and/or drawing number and/or serial number and/or material identification of the filter basket. The foregoing listing is only by way of example and is not to be interpreted definitively. The component-specific information stored on the identification means 21 can be read and/or written or overwritten magnetically, by way of infrared or radio.

[0244] The filter device 5 is connected in signal-conducting relationship to a control means (not shown). The control means is adapted to provide at least one control parameter for control of the filter device 5, wherein in this embodiment the control parameter is a rotary speed, a speed, a temperature, a conveyor volume flow or a pressure.

[0245] The control means is connected to a combined reading and writing device 16, 17 adapted to receive the component-specific information from the identification means 21 and/or overwrite or supplement same.

[0246] The control means can also be a control portion of the control means 13 (see FIG. 1).

[0247] The control means is adapted to adapt at least one of the above-mentioned control parameters in dependence on the component-specific information, to provide the component-specific information and in particular based on that information to carry out a diagnostic process and/or to produce a warning message.

[0248] Such a warning message or the result of the diagnostic process can for example include a recommendation to carry out a cleaning operation and/or a maintenance operation and/or replacement of the component provided with the identification means and/or a cooperating component of the filter device 5.

[0249] FIG. 5 shows the filter element 19 in detail. The filter element 19 is in the form of a cylindrical filter basket having a peripheral surface 33. Fixed to the peripheral surface is the identification means 21 which, as already described in relation to FIG. 1, has component-specific information.

[0250] FIGS. 6 to 8 show a granulator 7 which in the present case and preferably is in the form of an underwater granulator. The granulator 7 has a granulator housing 39 (see also FIG. 9) having a housing inlet 41 for the feed of polymer melt and a housing outlet (not shown) for the discharge of pellets or granules. The granulator 7 further has a blade protection 46.

[0251] In addition, the granulator 7 has a cooling chamber 45, an apertured plate 47, a blade head 49 as well as a drive 51 which provides a drive power output.

[0252] In operation the polymer melt issues from the blade head 49 (see FIGS. 7, 8, 14a, 14b) in the form of polymer strands (not shown), divided into strand portions.

[0253] The strand portions pass into the cooling chamber 45 in contact with a cooling fluid, in particular water, and are abruptly cooled down. The polymer strands are cut and form strand portions which in the course of the further procedure are removed from the water in the form of granules or pellets and are discharged through the housing outlet (not shown).

[0254] The drive 51 serves in particular for driving the blade head 49 adapted to cut the polymer strands into strand portions. The blade head 49 is rotatably mounted on an entrainment member 72 (see FIGS. 15a, 15b) and is connected by means thereof to a drive shaft 53 and the drive 51.

[0255] The assembly comprising drive 51, cooling chamber 45 as well as blade head 49 and apertured plate 47 is arranged on a machine carrier 55 having for example rollers for simplified positionability of the granulator 7.

[0256] The granulator 7 includes at least one identification means 21 for storing and providing at least one item of component-specific information. In that respect, preferably a respective identification means 21 is associated with the apertured plate 47 and the blade head 49 and is adapted to store at least one item of component-specific information of the blade head 49 or the apertured plate 47.

[0257] The item or items of component-specific information include an article number and/or a drawing number or a serial number and/or a material identification of the respective component and/or the structural size or dimensions and/or the structural shape and/or a composition and/or layer thickness of the wearing layer and/or an embodiment of series products and/or a maximum power output and/or a coefficient of friction or surface quality.

[0258] The granulator 7 is connected in signal-conducting relationship to a control means adapted to provide at least one control parameter, in particular a rotary speed, a speed, a throughput amount, a conveyor volume flow or a pressure.

[0259] The control means can also be a control portion of the control means 13 (see FIG. 1).

[0260] The control means is connected to a combined reading and writing device 15, 17 adapted to receive the component-specific information from the identification means 21 and/or to overwrite or supplement same.

[0261] The control means is adapted to adapt at least one of the above-mentioned control parameters in dependence on the component-specific information, to provide the component-specific information and in particular based on that information to carry out a diagnostic process and/or produce a warning message.

[0262] Such a warning message or the result of the diagnostic process can include for example a recommendation to carry out a cleaning operation and/or a maintenance operation and/or replacement of the component provided with the identification means and/or a cooperating component of the granulator 7.

[0263] The start-up valve 57 shown in FIGS. 8 and 10 includes a valve housing 59, at the outside of which there is a valve inlet 60 for fluid-conducting connection to the melting apparatus 3 (see FIG. 1) and a valve outlet 61 for fluid-conducting connection to the granulator 7, wherein the valve inlet 60 and the valve outlet 61 in the illustrated embodiment are advantageously disposed on opposite sides of the valve housing 59 and are in fluid communication. In order to fluid-tightly separate the valve inlet 60 and the valve outlet 61 from each other a valve body is accommodated in the valve housing 59 moveably along its longitudinal axis. The valve housing 59 could also be referred to as a valve spool.

[0264] Advantageously the valve body 59 can be reciprocated in known manner between its various valve positions by means of an actuator 58.

[0265] The start-up valve 57 preferably has a mounting accessory portion 62 for coupling to the granulator 7 and/or a carrier structure.

[0266] The start-up valve 57 preferably has an identification means 21 mounted to the valve housing 59. The identification means 21 is adapted to store at least one item of component-specific information of the start-up valve 57 and to provide it for the combined reading and writing device 15, 17 (see FIG. 6) connected to the control means of the granulator 7 or to the reading device 15 and the writing device 17 (see FIG. 1) connected to the control means 13 of the pelletizing apparatus 1.

[0267] The item or items of component-specific information include an article number and/or a drawing number or a serial number and/or a material identification of the respective component and/or the structural size or dimensions and/or the structural shape and/or a composition and/or a reaction or closure time and/or an embodiment of series products and/or a maximum power output and/or a coefficient of friction or a surface quality.

[0268] The reading and writing device 15, 17 is adapted in known manner to receive the component-specific information from the identification means 21 on the valve housing and/or to overwrite or supplement same.

[0269] The control means 13 or the control means of the granulator is adapted to adapt at least one control parameter, in the present case a speed, in particular a closing speed, or a conveyor volume flow of the granulator 7, in dependence on the component-specific information, to provide the component-specific information and in particular based on that information to perform a diagnostic process and/or provide a warning message.

[0270] Such a warning message or the result of the diagnostic process can include for example a recommendation to carry out a cleaning operation and/or a maintenance operation and/or replacement of the component provided with the identification means and/or a cooperating component of the start-up valve.

[0271] FIGS. 11a and 11b show the apertured plate 47 which in this embodiment is of a multi-part structure in the configuration of an electrically heatable heating flange 63 with a replaceable cutting plate 64 (not shown, see FIG. 13). To receive the cutting plate 64 the heating flange 63 has a cutting plate receiving means 64a.

[0272] The polymer melt is initially divided into a plurality of partial flows on the entry side of the heating flange 63 by means of a cone 65. The partial flows pass through passages 66 to the outlet holes 67 shown in FIG. 13 in the cutting plate 64.

[0273] In the present case a respective identification means 21 is mounted to the heating flange 63, in particular the periphery of the heating flange 63 and the cutting plate 64.

[0274] FIGS. 12a and 12b show the apertured plate 47 which in this embodiment is of a multi-part structure in the form of an oil-heatable heating flange 63 with a replaceable cutting plate 64. The heating flange 63 has a plurality of oil connections for the supply of heated oil and heating passages, through which the oil can be distributed in the heating flange 63. The rest of the configuration of the heating flange 63 does not differ from the embodiment shown in FIGS. 11a and 11b.

[0275] In the present case a respective identification means 21 is mounted to the heating flange 63, in particular the periphery of the heating flange 63 and the cutting plate 64.

[0276] The cutting plate 64 shown in FIG. 13 has outlet holes 67 which are arranged in a circle and through which plastic melt issues into the cooling chamber 45 (see FIG. 7), in this embodiment 16 uniformly distributed outlet holes 67. The blade head (see FIGS. 14a, 14b) rotates on the cutting plate 64 to sever the polymer strands issuing from the outlet openings. The cutting plate 64 is therefore preferably formed from a material which is as wear-resistant and media-resistant as possible, like for example stainless steel.

[0277] The identification means 21 is preferably arranged at the outlet side of the cutting plate 64 so that the polymer strands extend laterally along the identification means 21 and the polymer melt does not meet the identification means 21.

[0278] FIGS. 14a and 14b show the blade head 49 which can be mounted to the shaft 53 (see FIG. 7) and which has a gear-like main body 48.

[0279] The main body 48 has a central bore 69 into which the drive shaft 53 (see FIG. 7) can be fitted. By means of an entrainment member 72 (see FIGS. 15a, 15b) the main body 48 can then be mounted rotatably on the drive shaft 53 at a defined position along the longitudinal axis of the drive shaft 53.

[0280] The outer periphery of the main body 48 is adjoined by a plurality of blade holding arms 70 which taper outwardly similarly to the flanks of a tooth on a toothed gear, but in this case the blade holding arms 70 do not extend precisely radially outwardly but are preferably set at an angle, in particular less than 60 degrees, relative to the radius or diameter, in which respect other angles are also possible. A plurality of blades or blade elements 71 with a cutting edge are arranged at the blade holding arms 70.

[0281] The inclined positioning of the blade holding arms 70 in relation to the diameter means that a cutting edge on the blade element 71 performs a pulling cut when it meets one of the polymer strands issuing at the apertured plate 47 (see FIGS. 11 to 13).

[0282] As the blade elements 71 brush directly along the apertured plate 47 (see FIGS. 11 to 13) they are preferably made from a hard material. Further preferably individual blade elements 71 are replaceably coupled to the blade holding arms 70.

[0283] By way of example the blade elements can also be in the form of simple striker bars and are therefore neither whetted nor ground to a point.

[0284] In the present case a respective identification means 21 is arranged at a surface of the main body 48, that extends in orthogonal relationship with the longitudinal axis. In addition, thereto a further identification means 21 is preferably mounted to the blade 71 spaced in relation to the cutting edge.

[0285] FIGS. 15a and 15b show an entrainment member 72 coupled to the drive shaft 53 for the blade head (see FIGS. 14a, 14b). The entrainment member 72 has a part-cylindrical support portion 73 which at its distal end remote from the drive 51 in the installed state (see FIG. 5) has a mounting interface 75 with a corresponding mounting means 74. The mounting interface 75 is preferably in the form of a male thread and the mounting means 74 is in the form of a cap having a female thread, the cap being adapted to come into engagement with the male thread 75 in such a way that the blade head 49 can be accommodated and in particular clamped fast between the cap and a contact surface 77 of the support portion 73.

[0286] The support portion 73 is preferably in the form of a cowl and is mounted with a coupling ring 76 on the drive shaft 53 by means of a ball joint (not shown).

[0287] Preferably the identification means 21 is fixed to the support portion 73 and is adapted to provide component-specific information of the entrainment member 72. The identification means 21 is adapted to store at least one item of component-specific information of the entrainment members 72 and to provide it to the combined reading and writing device 15, 17 (see FIG. 6) connected to the control means of the granulator 7 or to the reading device 15 and writing device 17 (see FIG. 1) connected to the control means 13 of the pelletizing apparatus 1.

[0288] The item or items of component-specific information include an article number and/or a drawing number or a serial number and/or a material identification of the respective component and/or the structural size or dimensions and/or the structural shape and/or a composition and/or layer thickness of the wearing layer and/or an embodiment of series products and/or a maximum power and/or a coefficient of friction or a surface quality.

[0289] The reading and writing device 15, 17 is adapted in known manner to receive the component-specific information from the identification means 21 on the valve housing and/or to overwrite or supplement same.

[0290] The control means 13 or the control means of the granulator is adapted to adapt at least one control parameter, in the present case a speed, in particular a rotary speed of the blade head 49 or a conveyor volume flow of the granulator 7 in dependence on the component-specific information, to provide the component-specific information and in particular based on the component-specific information to carry out a diagnostic process and/or produce a warning message.

[0291] Such a warning message or the result of the diagnostic process can include for example a recommendation to carry out a cleaning operation and/or a maintenance operation and/or replacement of the component provided with the identification means 21 and/or a cooperating component of the entrainment member 72.

[0292] FIG. 16 shows a water treatment device 11 for cleaning process water from the granulation of residues of the polymer melt. The water treatment device 11 in this case is connected in fluid-conducting relationship to the drying device 9 (see also FIG. 1) and is so designed that, in drying of the granules or the pellets from granulation or underwater granulation, by the drying device 9, it cleans remaining process water.

[0293] FIG. 17 further shows a detailed perspective view of the water treatment device 11.

[0294] The water treatment device 11 includes a first housing portion 78 having an opening closable by a first cover 80 which is mounted to the housing portion 78.

[0295] The water treatment device 11 further preferably also includes a second housing portion 82 having an opening closable by a second cover 84 mounted to the housing portion 82.

[0296] A first water filter 86 is accommodated in the first housing portion 78. The water filter 86 includes a plurality of sieve elements 88 for filtering the process water. The sieve elements 88 have a flat sieve surface, wherein five sieve elements 88 are respectively accommodated in a sieve cassette 88 and are arranged grouped therein. A plurality of those sieve cassettes 88 is arranged in mutually adjoining relationship along a circular path and are accommodated in the housing portion 78 rotatably about an axis of rotation which is fixed through the center point of the circle and extends in the longitudinal direction of the sieve cassettes 88. Rotation of the sieve cassettes 88 is preferably affected by a drive (not shown).

[0297] The first housing portion 78 can be connected in fluid-conducting relationship to the granulator 7 or to the drying device 9, as shown in FIG. 16, so that the contaminated process water can pass into the housing portion 78. The water level in the housing portion 78 is monitored. Depending on the water level clean sieve cassettes 88 are moved into the process water or contaminated sieve cassettes 88 are removed from the process water so that clean sieve elements 86 are always available. The sieve cassettes 88 have to be regularly cleaned by virtue of contamination by residues of the polymer melt.

[0298] Accommodated in the second housing portion 82 is a second water filter 90 in the form of a continuously operable filter belt. The filter belt 90 shown in FIG. 18 is preferably disposed downstream of the sieve cassettes 88 and is of a higher level of filter fineness in order to be able to filter out even the finest residues which the sieve cassettes 88 do not filter out of the process water.

[0299] The filter belt 90 has a filter surface 92 which is guided on a holding means (not shown) and is continuously cleaned by means of a cleaning device 84.

[0300] As can be seen from FIGS. 16 to 18 the water treatment device 11 includes at least one identification means 21 for storing and providing at least one item of component-specific information. In that respect an identification means 21 is respectively associated with the first water filter 86 or the sieve cassette 88 and the second water filter 90 and is adapted to store at least one item of component-specific information of the water filters 86, 90.

[0301] As FIG. 18 shows the sieve cassette 88 includes a frame 89 adapted to accommodate the flat water filters 86. In that case the identification means 21 is mounted to the frame 89.

[0302] In addition, the filter element 19 mounted to the filter belt 90 is mounted to the holding means (not shown), as indicated in FIG. 17.

[0303] The item or items of component-specific information preferably include an article number and/or a drawing number or a serial number and/or a material identification of the respective component and/or the structural size or dimensions and/or the structural shape and/or filter surface and/or filter fineness and/or an embodiment of series products and/or a maximum filter capacity and/or a target filling level of the respective housing portion 78, 82.

[0304] The water treatment device 11 is connected in signal-conducting relationship to a control means adapted to provide at least one control parameter, in particular a water filling level, a belt speed of the filter belt 90, a throughput amount, a conveyor volume flow or a speed of rotation of the sieve cassettes 88.

[0305] The control means can also be a control portion of the control means 13 (see FIG. 1).

[0306] The control means is connected to a combined reading and writing device 15, 17 adapted to receive the component-specific information from the identification means 21 and/or to overwrite or supplement same.

[0307] The control means is adapted to adapt at least one of the above-mentioned control parameters in dependence on the items of component-specific information, to provide the component-specific information and in particular based on the component-specific information to carry out a diagnostic process and/or produce a warning message.

[0308] Such a warning message or the result of the diagnostic process can include for example a recommendation to carry out a cleaning operation and/or a maintenance operation and/or replacement of the component provided with the identification means and/or a cooperating component of the water treatment device 11.