DE102012008564A1 - Continuous casting apparatus for producing granules of melt material and method for their operation - Google Patents

Abstract

The invention relates to an apparatus and a method for producing granules from a melt material, for. B. plastic material, with a continuous casting apparatus (1), from which at least one strand (2) of the plastic material emerges, and a belt conveyor device (3) with at least one conveyor belt (4). on which the strand (2) can be fed to a granulating device (5) which divides the strand (2) into the granules (6), wherein a starting device (20) with at least one first strand guiding surface (21) is provided, wherein the starting device ( 20) along an axis parallel to the conveying direction of the conveyor belt (4) axis is movable, wherein in a first position of the starting device (20) from the continuous casting (1) emerging at least one strand (2) of the plastic material on the first Strangleitfläche (21) occur can and wherein the first Strangleitfläche (21) is arranged to guide in the first position on the Strangleitfläche (21) occurring strand (2) in a direction away from the granulator (5) direction.

Description

The invention relates to a device for producing granules of a melt material, for. B. plastic material or of any material to be granulated, which may have, for example, preferably the plastic material in terms of viscosity or the solidification properties similar properties, with a continuous casting, from which at least one strand of plastic material exits, and a belt conveyor with at least one conveyor belt on which the strand is fed to a granulator which divides the strand into the granules, according to the preamble of claim 1. The invention also relates to a method for operating such a device.

In general, in devices for the production of granules of melt material z. As plastic material or from any granulated material with a continuous casting the problem that it may come during operation, especially during the startup process, to breaks the strands. In particular during the starting process, the additional problem arises that the respective strand beginnings do not emerge quite evenly from a continuous casting apparatus. This is due on the one hand to any existing inhomogeneities in the strand material, but also for example by the fact that no equilibrium temperature profile could yet be established and no equilibrium between strand exit velocity from the continuous casting apparatus and strand withdrawal speed can be set from the beginning of the continuous casting apparatus. Especially when starting it is therefore particularly easy to strand breaks, unwanted inhomogeneities in the strands, unwanted superimposition of strands and the like.

The German patent application DE 4026337 describes a device for cooling and granulating molten plastic extruded strands of plastic with a transport chute and a downstream granulator. The transport channel consists of longitudinally grooved perforated plate or sieve material, so that the strands are carried and guided by a passing through the Transportinne gas stream. The transport channel has a catchment area, which can be arranged pivotable about an axis separately from the subsequent transport area. To start the device, if the strand material does not yet have the full quality properties, the catchment area can be pivoted upwards, so that emerging from the nozzle strands can fall down vertically into a collecting container. This solution requires a relatively complex construction of the transport chute and necessary for the formation of gas flow facilities. In addition, it is difficult to control the movement of the strand by means of the gas flow so that the strand moves as closely as possible according to a desired, in particular variable conveying speed.

From the international application WO 2009/052979 For example, a device for producing granules of plastic material is known, comprising a continuous casting device from which emerges a strand of the plastic material, and a belt conveyor with a conveyor belt for feeding the strand to a granulating device. The conveying direction of the conveyor belt can be switched between a Wegführförderrichtung of the granulating away during a start-up phase and a Zuführförderrichtung to the granulating out towards stationary conveying operation.

This approach has the disadvantage that the time at which the switching from Wegführförderrichtung to Zufuhrförderrichtung is very accurately determined and adhered to. This can be difficult to maintain because the timing may depend on changing parameters, such as differences in flow and / or the rate at which molten material exits the continuous casting apparatus. For clarification, the case is considered at first in which the conveyor belt initially moves in Wegführförderrichtung when starting, in order to convey excess, in particular qualitatively insufficient strand material in the waste position. If then the conveying direction of the conveyor belt is switched to the Zuführförderrichtung at a time to which not all excess waste material was discharged to the waste position, this waste material of insufficient quality can remain on the conveyor belt and can also be transported to the granulator and processed into granules, which is undesirable. In this case, there is thus an early switching of the conveying direction. The reverse case of too late switching may also be detrimental. In this case, it may happen that, after severing the melt material emerging from the continuous casting apparatus, the strand strikes the conveyor belt which is still moved in the removal direction. The tip of this newly formed strand is therefore bent in a direction away from the granulation device. Until stopping the conveyor belt and switching the conveying direction in the Zuführförderrichtung while further melt material is fed to the conveyor belt, which collects on this. It can therefore happen that an excessive amount of enamel material at the strand start on the conveyor belt accumulates, which can cause the strand bulges and bends away from its desired position on the conveyor belt. In extreme cases, this can lead to adjacent strands on the conveyor belt coming into contact or even overlapping.

It is thus an object of the present invention, an apparatus and a method for producing granules of a melt material z. As plastic material or to be granulated material to provide with a continuous casting, which (s) overcomes the disadvantages of the prior art and in a simple and thus cost-effective way, a more reliable operation, especially when starting allows.

The object is achieved by a device having the features according to claim 1 and by a method having the features according to claim 10.

Preferred embodiments are defined in the respective subclaims.

The inventive device is used to produce granules of a melt material z. B. plastic material or from material to be granulated with a continuous casting, from which at least one strand of the material to be granulated emerges, and a belt conveyor with at least one conveyor belt on which the strand of a granulating device can be fed, which divides the strand into the granules.

According to the invention a starting device is provided with at least a first Strangleitfläche, wherein the starting device is movable along an axis parallel to the conveying direction of the conveyor belt, wherein in a first position of the starting device emerging from the continuous casting strand of the plastic material can occur on the first Strangleitfläche and wherein the Strangleitfläche is set up in the first position to guide the strand occurring on the strand guiding surface in a direction away from the granulating device.

The inventive design with a movable starting device having at least one Strangleitfläche to derive the strand in a first position, the inventive device for producing granules in a relatively simple and cost-effective manner, a more reliable operation, especially when starting the device.

The invention can thus enable automatic and reliable granulation of various materials, in particular plastics. A great advantage can lie in the simple yet automatic operation of the device. The device according to the invention can be used, for example, in highly filled plastic compounds and tension-sensitive plastics, as well as in recycling processes which lead to frequent strand breaks in conventional granulation processes.

The term plastic material according to the invention is also to be understood as meaning, for example, preferably any material to be granulated. Areas of application or materials to be granulated may be: thermoplastics, elastomers, biopolymers (biodegradable plastics), antioxidants, oleochemicals, for example fatty acids and glycerols, alcohols and metal soaps, surfactants and lubricants, for example PE and PP waxes, hot melt adhesives and resins (for example based on PP, SAN), melt-like polymers, oligomers and low molecular weight polymers, plastic material-based dyes, chemicals, pharmaceuticals and other materials suitable for strand pelletizing.

During operation of the starting device in the first position, the strand can preferably be caught by a strand collecting container.

More preferably, the starting device has a second Strangleitfläche, wherein in a second position of the starting device emerging from the continuous casting strand of the plastic material may occur on the second Strangleitfläche and wherein the second Strangleitfläche is set up in the second position occurring on the Strangleitfläche strand in a direction facing the granulator direction to deposit on the conveyor belt to guide. In this way, a storage of at least one strand on the conveyor belt can be made more reliable.

According to the invention, the starting device can thus be moved at least between a first and a second position. In this case, the first position can serve to promote the material to a waste position in the event of unwanted production operation, and in the second position, the material can be transported into the granulator for granule production, the device thus being able to be operated automatically according to the invention.

In order to ensure an optimal cooling effect and thus, in particular depending on the strand material reliable and uniform strand guidance, by which a strand break, for example, by setting a certain strand temperature, in particular a strand temperature at the surface of the strand, can be avoided, the starting device assigned or in the starting device provided funds, such as Spray nozzles, be provided, which allow a rinse the at least one Strangleitfläche with a cooling fluid, in particular water. Furthermore, spray nozzles may be provided for a cooling fluid at the top and / or bottom of the conveyor belt. In particular, the conveyor belt may consist of a mesh of suitable material, so that the cooling fluid also has optimum contact with the at least one strand. In order to further stabilize the deposition of the strands on the belt conveyor device according to the invention in a simple and cost-effective manner, and thus to reliably avoid entanglement or strand breakage, the strand conveyor, which is the strand casting device, is at least in a storage area outlet, is deposited on the conveyor belt, a pan plate provided under the conveyor belt, wherein the spray nozzles may preferably be arranged directed in the storage area or on the storage area. Thus, particularly in the area of the storage of the strands on the starting device and / or on the belt conveyor device, a particularly good cooling possibility and / or mechanical guidance of the strands or of the at least one strand is made possible.

Depending on the material used, it can be particularly advantageous for a suction and / or blow-off device to be provided for sucking off and / or blowing off the cooling fluid from the strand, wherein these devices may preferably be provided in the region shortly before the granulating device.

In order to be able to easily avoid during the starting process that excess melt material can escape from the continuous casting apparatus, a separating device can be provided for severing the at least one strand in the region of the strand outlet opening.

In order to be able to provide a most extensive adaptation to different material strands to be granulated, the height and / or inclination of the belt conveyor device can be adjustable.

In order to protect at least the area between the continuous casting apparatus and the granulating device there the at least one strand from environmental influences or to protect the operating personnel in terms of occupational safety against possible outgassing or the like there, the device according to a preferred embodiment thereof, at least the range between the continuous casting device and the granulating device are surrounded by a housing sealing against the environment.

The inventive method for operating a device for producing granules of melt material, for. B. plastic material or from material to be granulated comprises the following steps: production of at least one strand of the melt material or to be granulated material by continuous casting; Feeding the strand to a granulating device by means of a belt conveyor with at least one conveyor belt; Dividing the strand into granules by the granulating device; wherein during a start-up phase or at least during a start-up phase, a starting device is positioned with a first Strangleitfläche in a first position, such that the at least one strand impinges on the first Strangleitfläche and is directed by this in a direction away from the granulator direction.

According to the invention, the starting device for the production operation can be positioned in a second position such that the at least one strand strikes a second strand guide surface and is guided by the latter in a direction pointing towards the granulating device for depositing onto the conveyor belt.

In order to enable a particularly simple, cost-effective and reliable adaptability for the operation of a device with the method according to the invention, in particular an adaptation to different materials to prevent strand breaks, the positioning of the starting device, a conveying speed of the conveyor belt, an extrusion speed of at least one strand and a feed rate of the granulator individually or together adjusted so that a specifically adjustable stretching or compression of the plastic material or of the material to be granulated material of the strand is made.

According to the invention, a conveying speed of the conveyor belt, an extrusion speed of the strand and a feeding speed of the granulating device can be set individually or together so that starting or stopping the process without occurrence of agglomerations by accumulations of the plastic material or the material to be granulated in the region of the belt conveyor the granulating takes place. By means of corresponding preferred method control according to the invention, the material inflow and outflow in all regions of the device according to the invention can be preferably adjusted in accordance with the method according to the invention.

Generally, it should be noted that all features of the invention, which are related above are described with the device according to the invention, also apply accordingly in connection with the method according to the invention and vice versa.

A typical application of the invention would be, for example, as follows: From the continuous casting apparatus several strands, for example of plastic material, are extruded. When starting the device, the starting device is positioned in a first position, which may also be referred to as a discharge position. The extruded strands strike the first strand guiding surface of the starter and are discharged towards the waste position below the spray head of the continuous casting machine. During the actual production operation of the device, the starting device is positioned in a second position, which may also be referred to as a production position. The extruded strands now impinge on the second strand guiding surface of the starting device and are directed in the direction of the granulating device, so that they can be deposited on the conveyor belt.

An application of a cooling fluid, preferably for example water or even gaseous cooling fluid, is arranged so that the strands are cooled when hitting the starting device and / or the conveyor belt and thus any sticking of the strands to the starting device or to the conveyor belt is avoided. When the device according to the invention is switched to production operation, the starting device is moved from the discharge position into the production position. In the meantime, the separating device, which may preferably be controlled automatically, cuts through the plastic strands in the region of the strand outlet opening. The strands are now carried on the upper run of the conveyor belt and acted upon by a cooling fluid. The length of the belt and the amount and temperature of the cooling fluid depend on the required cooling properties. Preferably, the material to be granulated should be cut resistant during granulation and no longer tend to stick. Preferably, in the last section of the belt or in the region in front of the granulating device, the adhering cooling fluid is sucked off or blown off the strands and on the conveyor belt with a suction and / or blow-off device. Thereafter, the strands leave the belt and arrive in a subsequent transition shaft, where the strands are conveyed and fed into an intake train of a granulator.

The invention will be described below by way of example with reference to the figures.

1 shows in a side view by way of example a device for producing granules of a material to be granulated with a continuous casting apparatus according to a preferred embodiment of the invention.

2 shows a section of the device of 1 during a start-up phase.

3 shows an exemplary starting device, which in the apparatus of the 1 can be used.

Like in the 1 is shown in the production plant from the continuous casting 1 at least one strand 2 the melt material z. B. extruded plastic material. In the in 1 shown production operating state hits the extruded at least one strand 2 on a second strand control surface 22 a starting device 20 which the strand 2 so that it leads to the filing on at least one conveyor belt 4 a belt conveyor 3 comes. With the at least one conveyor belt 4 is the strand 2 a granulator 5 fed, which the strand 2 into the granules 6 divided. As indicated by the corresponding arrows in 1 indicated, the belt conveyor device 3 a Zuführförderrichtung the conveyor belt 4 to the granulator 5 towards. The continuous casting machine 1 is with at least one strand outlet opening 7 above the belt conveyor 3 arranged.

The starting device 20 is along a to the conveying direction of the conveyor belt 4 extending axis movable or displaceable, as indicated by the arrows in the 1 displayed. In this way, the starting device in a space between the strand outlet 7 and the conveyor belt 4 be offset so that the out of the strand outlet 7 leaving at least one strand 2 on a first control surface 21 or a second strand guide surface 22 incident.

The 2 shows in the clipping the device of 1 during a start-up phase. The starting device 20 is in this initial phase in a first position, which may also be referred to as Ableitstellung, towards the granulator 5 shown offset, so that from the strand outlet 7 emerging strand on the first strand control surface 21 the starting device impinges. The first control surface 21 is in one of the granulator 5 pointing away towards the bottom, so that the strand 2a is derived in this direction away and from a strand catcher 15 can be caught. If the quality of the out of the strand outlet 7 leaving at least one strand 2 stabilized and reached the desired level can be converted to the actual production operation. For this purpose, the starting device 20 in one direction from the granulator 5 path in a second position, which can also be described as a production position, as in the 1 is shown. In the production position, it comes out of the strand outlet opening 7 leaving at least one strand 2 on the second control surface 22 the starting device 20 on. The second control surface 22 is in the to the granulator 5 pointing downward direction so that the at least one strand 2 is directed in this direction, so the strand 2 in the conveying direction of the conveyor belt 4 on the conveyor belt 4 can be stored and transported.

An exemplary embodiment of a starting device 20 will now be related to the 3 described. Like in the 3 shown, the start-up device 20 the first control surface 21 for deriving the at least one strand 2a in one of the granulator 5 direction away, as well as the second Strangleitfläche 22 for conducting the at least one strand 2 in one to the granulator 5 pointing direction. It is preferred that the first and / or the second Strangleitfläche 21 . 22 with a cooling fluid, such as water, are flushable. For this purpose, in the starting device 20 a cooling fluid inlet 23 as well as cooling channels 24 be provided. The cooling channels 24 preferably run underneath and along the first and / or second strand guiding surface 21 . 22 to serve for temperature control. jet 25 for the cooling fluid may be along an edge, at the first and second strand guide surface 21 . 22 adjacent to each other, be arranged. To prevent from the nozzles 25 Exiting cooling fluid undesirably splashes up, one can over the nozzles 25 arranged splash guard 26 be provided. That from the nozzles 25 exiting cooling fluid then flushes the first and / or second Strangleitfläche 21 . 22 , The coolant inlet 23 can be switched, for example, by a valve arranged there, z. B. a multi-way solenoid valve, (in the 3 not shown), which z. B. can completely interrupt the inflow of coolant and / or only the inflow of coolant to the first Strangleitfläche 21 or the second strand guide surface 22 allowed. Also a manually or electrically or hydraulically swiveling executed splash guard 26 is conceivable (indicated by the double arrow in the corresponding 3 ), which thus by contact of a respective longitudinal edge thereof either with the Strangleitfläche 21 or the second strand guide surface 22 there can interrupt the flow of coolant. The amount of inflowing cooling fluid can be adjusted depending on the operating situation of the device according to the invention, in the start-up phase in the first position of the starting device rather only one sufficient to accompany the at least one start-melt strand amount of coolant is supplied when starting in the second position the starting device when the at least one melt strand for storage on the conveyor belt is supplied, the amount of coolant is increased at least for a short time and in the (stationary) operation of the device then rather the amount of coolant is reduced again compared to starting slightly.

Like in the 3 shown, the start-up device 20 preferably a first strand guide surface 21 and a second strand guide surface 22 on. However, this is not limiting, and it may only be the first Strangleitfläche 21 be provided for the derivation of the at least one strand 2 serves. In the production plant is then from the strand outlet 7 leaving at least one strand 2 not from the starting device 20 but hits directly on the conveyor belt 4 ,

In addition, the first and / or second strand guide surface 21 . 22 not necessarily designed as straight planes, as in the 3 shown. It is also possible that one or both of the strand guide surfaces 21 . 22 in a curved shape, or in sections are straight and curved. Thus, the first and / or the second Strangleitfläche 21 . 22 convexly curved so as to receive and deposit the at least one strand 2 in approximately parallel direction to the exit direction of the at least one strand 2 from the strand outlet 7 or the conveying direction of the conveyor belt 4 he follows.

Referring again to the 1 are spray nozzles 16 . 17 for a cooling fluid at the top and at the bottom 4 of the conveyor belt 4 intended. A pan plate 9 is under the conveyor belt 4 at least in a storage area of the belt conveyor 3 provided where the strand 2 on the conveyor belt 4 is filed. The spray nozzles 16 are at least partially arranged in the storage area. A suction and blow-off device 18 is provided for sucking and blowing off the cooling fluid from the strand 2 , A separator 13 serves to sever the strand 2 in the region of the strand outlet opening 7 ,

Generally, at least the belt conveyor 3 adjustable in height and / or inclination. Also the continuous casting machine 1 can be adjusted accordingly in height and also the granulator 5 can be adjusted accordingly in height. About feed rollers 10 . 11 via a known per se cutting device 13 a granulation of the at least one strand 2 in granules 6 in the area of the granulator 5 ,

As in the 1 In the embodiment shown, the entire plant is essentially encapsulated by environmental influences. The device is substantially completely of a sealing housing or of sealing Housing parts which are zusammenführbar surrounded surrounded, in particular airtight. Thus, a particularly safe operation can be made possible with extensive exclusion of environmental influences. Thus, at least in the region between the continuous casting device and the granulating device there, the at least one strand can be protected from environmental influences or the operating personnel can be protected there against any possible outgassing or the like in the sense of occupational safety.

The device according to the invention or the method according to the invention allows simple, cost-effective and reliable operation, in particular during start-up, with the greatest possible automation or even complete automation being possible.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4026337 [0003]
• WO 2009/052979 [0004]

Claims (13)

Apparatus for producing granules of melt material, comprising a continuous casting apparatus ( 1 ), from which at least one strand ( 2 ) of the melt material, and a belt conveyor ( 3 ) with at least one conveyor belt ( 4 ). on which the strand ( 2 ) a granulating device ( 5 ) is fed, which the strand ( 2 ) into the granules ( 6 ), characterized in that further comprises a starting device ( 20 ) with at least one first strand guide surface ( 21 ) is provided, wherein the starting device ( 20 ) along a to the conveying direction of the conveyor belt ( 4 ) parallel axis, wherein in a first position of the starting device ( 20 ) from the continuous casting apparatus ( 1 ) leaving at least one strand ( 2 ) of the melt material onto the first strand guide surface ( 21 ) and wherein the first strand guide surface ( 21 ) is set up, in the first position on the Strangleitfläche ( 21 ) strand ( 2 ) in one of the granulating device ( 5 ) directing away direction. Apparatus according to claim 1, characterized in that during operation of the starting device ( 20 ) in the first position of the at least one strand ( 2 ) from a strand catcher ( 15 ) is trappable. Apparatus according to claim 1 or 2, characterized in that the starting device ( 20 ) a second strand guide surface ( 22 ), wherein in a second position of the starting device ( 20 ) from the continuous casting apparatus ( 1 ) emerging strand ( 2 ) of the melt material onto the second strand guide surface ( 22 ) and wherein the second strand guide surface ( 22 ) is set up in the second position on the Strangleitfläche ( 21 ) strand ( 2 ) in a to the granulating ( 5 ) pointing towards the storage on the conveyor belt ( 4 ). Device according to one of claims 1 to 3, characterized in that the starting device ( 20 ) Has means to control the strand guide surface (s) ( 21 . 22 ) with a cooling fluid. Device according to one of claims 1 to 4, characterized in that spray nozzles ( 16 . 17 ) for a cooling fluid at the top and / or bottom of the conveyor belt ( 4 ) are provided. Device according to one of claims 1 to 5, characterized in that at least in a storage area of the belt conveyor device ( 3 ), where the strand ( 2 ), which from the continuous casting ( 1 ), onto the conveyor belt ( 4 ), a pan plate ( 9 ) under the conveyor belt ( 4 ) is provided, wherein the spray nozzles ( 16 . 17 ) are arranged directed in the storage area or on the storage area. Apparatus according to claim 4, 5 or 6, characterized in that a suction and / or blow-off device ( 18 ) is provided for sucking and / or blowing off the cooling fluid from the strand ( 2 ). Device according to one of claims 1 to 7, characterized in that a separating device ( 13 ) is provided for the separation of the strand ( 2 ) in the region of the strand outlet opening ( 7 ). Device according to one of claims 1 to 8, characterized in that at least the area between the continuous casting ( 1 ) and the granulating device ( 5 ) is surrounded by a sealing against the environment housing. A method of operating a device for producing granules of melt material, comprising the steps of: producing at least one strand from the melt material by continuous casting; Feeding the strand to a granulating device ( 5 ) by means of a belt conveyor ( 3 ) with at least one conveyor belt ( 4 ); and dividing the strand into granules ( 6 ) through the granulating device ( 5 ); wherein during a start-up phase a starting device ( 20 ) with a first strand guide surface ( 21 ) is positioned in a first position, such that the at least one strand ( 2 ) on the first strand guide surface ( 21 ) and from this into one of the granulating device ( 5 ) is directed away. Method according to claim 10, wherein the starting device ( 20 ) is positioned in a second position, such that the at least one strand ( 2 ) on a second strand control surface ( 22 ) and from this into a granulation device ( 5 ) is directed towards the storage on the conveyor belt ( 4 ). The method of claim 10 or 11, wherein a positioning of the starting device, a conveying speed of the conveyor belt, an extrusion speed of the strand and a Feeding speed of the granulating individually or together adjusted so that a specifically adjustable stretching or compression of the plastic material of the strand is made. The method of claim 10, 11 or 12, wherein positioning of the start-up device, a conveying speed of the conveyor belt, an extrusion speed of the strand and a feeding speed of the granulating device are set individually or together so that starting or stopping the process without occurrence of agglomeration by accumulations of the plastic material takes place in the area of the belt conveyor and the granulator.

Images