EP3003864B1 - Packing machine and method - Google Patents

Description

The present invention relates to a packing machine for filling bulk goods in containers and a method. Here, bulk goods are filled in particular in valve bags.

When filling valve sacks, the valve sacks are pushed onto a usually approximately horizontally oriented filler neck and then filled through the interior of the filler neck. After removal, the valve bag valve closes the opening in a self-sealing manner, or an additional weld is made to close the valve.

In the present packaging machine, a supply of bulk materials to be filled is stored in a product supply. One or more filling nozzles each have a conveyor assigned. The conveyor may comprise a Fülltopf and a conveyor turbine. A conveyor turbine, which is constructed similarly to a rotary valve, promotes by turning the turbine blades, the bulk material from the Fülltopf in the filling channel connected thereto, at the end of the product outlet is provided. The product outlet is located at the filler neck.

When filling bulk materials in containers such as valve sacks or open sacks, it is usually necessary when filling eg building materials such as cement to add compressed air for fluidizing the bulk material to be filled. By adding compressed air, the bulk material is held or made flowable, so that an effective filling is possible. However, the addition of air causes the internal pressure in the container to rise during filling. This internal pressure must be largely reduced before acceptance of the container, so not a considerable part of the filled bulk material escapes during the removal of the filler neck by the pressure reduction and thus pollutes the environment of the packing machine. This applies all the more to the filling of bulk materials in containers made of, for example, polyethylene films or the like, since the film wall is impermeable to air.

Ensuring the cleanliness of a bottling plant is becoming increasingly important. With the DE 41 00 658 C2 For this reason, a method and a filling machine for filling flowable filling material into valve sacks have become known in which compressed air is blown into the interior of the filling turbine or filling tube by throttle valves when the weight increase during the filling process falls below a standard value. This procedure avoids the constant addition of air during the filling process, so less air is introduced into the bag. Thereby, the waiting time for venting after the end of the filling process can be reduced. The disadvantage of this, however, is that the filling conditions change significantly from one bag to another and even during a filling process, since sometimes air is added and sometimes not. Another disadvantage is that even with such a filling process even at the end of the filling process still a relatively high internal pressure prevail in the valve bag, which can lead to a considerable ejection of bulk material when the bag is removed and the internal pressure when the air escapes abruptly degrades. This can only be prevented by an increased waiting time at the end of the filling process, to provide more time for the pressure reduction from the bag interior. However, this reduces the cost-effectiveness of the system. In addition, however, can not be guaranteed that the inner bag pressure degrades quickly enough.

It is therefore with the EP 1 860 027 B1 a plant and a method for filling sacks has become known, wherein during the filling process, a measure of the pressure prevailing in the bag internal pressure is measured and wherein during the filling of the bag a filling parameters such. B. the air supply is controlled in response to the pressure prevailing in the bag internal pressure to accelerate the processing of the bag. This prior art system works satisfactorily and enables rapid filling of bulk materials in valve bags while at the same time optimizing the cleanliness of the system. The disadvantage of this, however, is the significantly increased apparatus complexity, since each filler neck must be equipped with a separate pressure sensor to detect a measure of the prevailing in the valve bag pressure level. Particularly in the filling of abrasive materials and building materials such as cement very high demands are placed on the materials used and measuring systems, since they must work reliably 24 hours a day, 7 days a week.

Since packaging machines are often equipped as rotating packing systems with 8, 12 or 16 filler neck, even a defect of a single filler neck can lead to significant downtime of such a packing machine.

A filling plant according to EP 1 860 027 B1 Therefore, it is mainly used in the filling of particularly lightweight materials such as soot particles or TiO 2 particles or the like, in which a particularly high amount of air is contained. For other applications, the system is too expensive.

Before the described prior art, it is therefore an object of the present invention to provide a packing machine and a method for filling bulk materials in containers available, whereby a high degree of cleanliness of the system can be ensured and in which the equipment cost is less.

This object is achieved by a device having the features of claim 1 and by a method having the features of claim 10. Preferred developments of the invention are the subject of the dependent claims. Further advantages and features of the present invention will become apparent from the general description and the description of the embodiment.

The packing machine according to the invention serves to fill bulk goods in containers and comprises at least one product supply, at least one filling pot, at least one conveying device, which comprises a conveyor turbine, a pump or a screw, further comprising at least one filler neck, at least one ventilation device with at least one ventilation valve and at least one ventilation nozzle on the product path between the product supply and at least one product outlet. The product outlet is preferably provided on the filler neck. The venting valve is controllably controlled by a control unit, and the control unit and the venting valve are adapted to set the amount of air passing through the venting nozzle and / or the effective amount of air passing in a period of time at the beginning of a filling operation greater than a period of time at the end of the filling operation , The control unit is designed and configured to start the ventilation before the start of filling.

The packing machine according to the invention has many advantages. A significant advantage of the packing machine according to the invention is that no additional pressure sensor is needed at each filler neck to ensure effective cleanliness of the packing machine. The fact that the control unit sets the amount of air passing through at the beginning of the filling process, as at the end of the filling can be effectively ensured that the pressure prevailing in the container internal pressure is considerably lower than in the prior art, as the total amount of air reduced and especially to the filling end, if As the product fills the container more and more, less air is added. As a result, the discharge of bottled bulk material can be reliably prevented during the removal of the container from the filler neck. Thus, the invention allows a cheap way a particularly reliable packaging machine, in which a particularly high reliability can be achieved by reducing the number of components.

It has surprisingly been found that the total amount of air supplied to a container during a filling process can be considerably reduced if initially a higher quantity of air is adjusted and this is subsequently considerably reduced. A continuously constant amount of air from the beginning of the filling process to the end leads to similar flow properties of the bulk material to be filled to a total of significantly larger amount of air in the container passes, whereby the internal pressure in the container at the end of the filling process is correspondingly higher. This results in greater pollution and / or a significantly longer waiting time at the end of the filling process.

If the amount of air supplied during the entire filling process is reduced, it can happen that some containers can be reliably filled first and that then the filling speed is significantly reduced or no more material is introduced because the material blocks and / or forms bridges.

The ventilation device comprises at least one valve device and at least one ventilation nozzle. The valve device may be connected to the ventilation nozzle via a compressed air connection. The valve device may be provided directly on the ventilation nozzle or also spaced therefrom. For example, the valve device may be arranged in or on a control cabinet, while the ventilation nozzle is arranged on the product path, for example on the conveyor and / or on the filler neck.

An important advantage of the invention is also that the degree of filling of the containers can be improved. The fact that a lower proportion of air enters the container, the volume of the container can be reduced. If, for example, the container is reduced by 5% or only 2% or even only 0.5%, the costs for the containers can be correspondingly reduced. When operating with sixteen fillers and operating 24 hours a day, seven days a week, the cost of the packaging material can be reduced accordingly. Also, the storage space and the transport volume can be reduced slightly.

An additional advantage is that also the weight accuracy can be improved. Due to the fact that practically no material escapes when the container is removed from the filler neck, not only is the cleanliness increased, but the accuracy is also improved. The weight accuracy is also increased by the improved control of the filling process, as by the optimized air supply of the filling the coarse and fine flow phases controlled better and so the weight gain in the fine flow phase can be made smaller. This results in an even more accurate shut-off point with less system-related caster. Preferably, during at least part of the filling operations, a characteristic of the course of the filling weight over the filling time is determined and stored in a memory device as historical data. The characteristic of the course of the filling weight over the filling time may include all recorded filling weight data. It is also possible and preferred to derive at least one characteristic value from the course of the filling weight over the filling time and to take it into account in the control of a subsequent filling operation. Then, the addition of air to the course of the filling weight over the filling time of at least one previous filling operation can be adjusted. The amount of air can be reduced if the fill curve shows that too much air has been added. The amount of air can be increased in a subsequent filling process, if it follows from the course of the filling weight over the filling time that too little air was added.

Preferably, the control unit is designed and configured to change the control of the ventilation valve in a subsequent filling operation in dependence on stored historical data.

The control unit is preferably designed and set up to take into account the historical data of several past filling operations. This can be done by forming averages over several fillings.

In all embodiments, it is possible for the amount of air supplied by the at least one ventilation valve to be adjusted via a variation of the ventilation cross-section of the ventilation valve. But it is also possible that the air pressure used is varied to adjust different amounts of air.

Particularly preferably, the ventilation valve is designed as a proportional valve or comprises at least one such proportional valve. The vent valve may be formed as a solenoid valve and then includes in particular at least one electrical coil and at least one biasing unit, preferably designed as a spring, for biasing the venting valve to a preferred position. The preferred position may be, for example, the closed position. The vent valve may include a control cone, a pole tube, and an armature to adjust a corresponding vent area in response to the applied current. Preferably, the ventilation cross section of the ventilation valve is adjustable at least in a plurality of stages. Preferably, the ventilation cross-section is quasi-continuously or continuously adjustable. This allows a particularly accurate control of the passing air flow.

In all embodiments, it is preferred that a characteristic curve of the ventilation valve is stored in the control unit. In this case, the characteristic can also take into account in particular hysteresis effects. This allows a particularly accurate control of the ventilation valve.

The control unit is preferably designed and configured to set the effective ventilation cross section of the ventilation valve via at least one pulse width modulation method. A pulse width modulation method allows simple and effective control of the amount of air passing through the vent valve. In a pulse width modulation method, an interval duration of less than 1 second and in particular less than 100 milliseconds is preferably set.

In particularly preferred embodiments, an interval duration is less than 50 milliseconds and in particular less than 25 milliseconds. In a specific embodiment, 20 milliseconds were set as the interval duration. In a pulse width modulation method, the time portion of an interval duration is set in which the ventilation valve is energized, for example. If, for example, a power supply is applied over a period of 10 milliseconds for an interval duration of 20 milliseconds, the coil is energized for 50% of the entire interval duration.

After an interval has elapsed, each interval repeats until the pulse width is modulated differently.

Preferably, the filling nozzle is associated with a weighing unit to detect a measure of a weight of the associated container. It is possible that a gross weight is recorded. It is also possible to detect a differential weight, in which, for example, the conveyor is weighed separately and is deduced in the from the weight loss of the product stock on the filled into the container weight. It is also possible that the container is weighed separately, for example, with an associated sack chair and is deduced from the weight determined on the filled in the container weight.

It is particularly preferred that at least one ventilation nozzle is provided on the filling channel between the conveyor and the product outlet of the filling nozzle. It is also preferred that at least one ventilation nozzle is provided on the conveyor. It is possible that only individual air vents are provided controllable in terms of their amount of air. It is also possible and preferred for all or substantially all of the ventilation nozzles to be controllably provided with regard to their air quantity.

In preferred embodiments, a shut-off device is provided in the filling channel. The shut-off device can also be referred to as a metering device, since the shut-off device is provided not only for completely closing or releasing the filling channel on a regular basis, but also for adjusting the coarse flow and the fine flow. In this case, a part of the filling channel is closed to adjust the fine flow with the shut-off device, so that no longer the entire filling cross-section is available. As a result, the conveyor effectively delivers less bulk material through the filling channel into the container. In preferred embodiments, it is also possible to set two or more different coarse flows and two or more different fine flows.

Preferably, at least one ventilation nozzle is provided in front of and / or behind the shut-off device.

In preferred embodiments, the ventilation device comprises or at least one ventilation device has an annular body with an inner passage cross-section and at least one ventilation channel at least partially surrounding the passage cross-section. In this case, the ventilation valve preferably comprises at least one annular ventilation channel which at least partially and in particular substantially completely surrounds the inner cross section of the filling channel.

In all embodiments, it is preferable for a filling channel to extend from the conveying device. The filling channel ends at the product outlet of the filling nozzle. The filling channel is thus at least partially formed by the filler neck. In preferred developments, the annular body of the ventilation device forms with its inner passage cross section a portion of the filling channel. Preferably, the annular ventilation channel surrounds the inner cross section of the filling channel. As a result, a particularly effective and uniform air supply of the filling channel is achieved.

In all embodiments, it is preferred that at least two ventilation devices are provided. It is possible that two different ventilation devices are provided on the filling channel. It is also preferable that two ventilation nozzles are provided on the filling channel. The two ventilation nozzles can open separately to the filling channel and / or open into the annular ventilation channel of the annular body.

In all embodiments, it is preferred that the control unit is designed and configured to control the amount of air through the ventilation nozzle in dependence on at least one parameter. The parameter is taken in particular from a group of parameters which the current filling weight of the container, the past filling time, a measured or estimated filling level in the container, the bulk material temperature, the ambient temperature, the bulk moisture, the ambient humidity, the previous service life of the packing machine, the Art of the bulk material to be filled and other measured values of the bulk material to be filled and the environment of the bulk material and the packaging machine.

Such a development will be a particularly effective Design allows. If, for example, the service life of the packing machine is taken into account, an increased amount of air can initially be supplied for a longer service life of, for example, two or more hours until some bags have been filled. The ambient temperature and the bulk material temperature in the product reservoir also have a considerable influence on the flow properties of the bulk material, so that taking these parameters into account leads to a significant improvement in the filling behavior. As a result, the cleanliness of the packing machine and its environment can be increased, since these measures normally allow the amount of air supplied can be reduced. Depending on the product, the ventilation devices can also be operated differently.

The control unit is configured and configured to start ventilation through the vent valve prior to commencement of filling. The beginning of the filling is understood here to mean the start of the conveying element and / or the opening of the shut-off device. If, for example, some air is already supplied to the bulk material before opening the shut-off device or z. B. after a standstill, so improve the flow properties of the bulk material to be filled, which subsequently the amount of air supplied can be reduced accordingly. The supply can also only from the conveyor z. B. done as a compressed air pulse.

In all embodiments, it is preferred that the filling process comprises at least one coarse stream and at least one fine stream. In this case, the control device is designed and set up to reduce the effective air volume of the ventilation valve already during the coarse flow or during the fine flow. In particularly preferred embodiments, the effective air quantity of the ventilation valve is reduced during the coarse flow. A filling process comprises at least one coarse flow and a subsequent fine flow. In the transition from the coarse flow to the fine flow, for example, the shut-off valve can be partially closed to the inlet cross-section into the filling channel or a passage cross-section in the Reduce filling channel. It is also possible that the delivery rate of the conveyor is reduced in order to promote a smaller amount of bulk material.

Preferably, the control unit is adapted and arranged to cause an adjustment of a control profile when the filling time changes by a predetermined amount. For example, if it is found that the filling time has been extended or shortened, the amount of air can be increased or decreased in a corresponding manner, for example, to achieve an adaptation to changing environmental conditions.

In all embodiments, it is possible and preferred that a plurality of ventilation valves are connected in parallel and / or in series.

By a parallel connection of several ventilation valves can be done in a simple manner, a stepwise variation of the amount of air, even if the individual ventilation valves do not allow proportional control of a ventilation cross-section, but only on and off.

The control unit is preferably designed and configured to control a subsequent filling operation as a function of historical data stored in a storage device. The historical data has preferably been recorded during at least one previous fill operation. The historical data may be direct measurements or at least one derived measure. In particular, the dead time or a characteristic number derived therefrom of a preceding filling operation is suitable for controlling. Effective control has also been achieved with measures characterizing the weight increase in the coarse flow and / or the weight increase in the fine flow. Good results were achieved with a figure that characterizes the ratio of the weight increases in coarse and fine flow.

The inventive method is used for filling bulk materials in containers by means of a filling operation on a packaging machine. The bulk goods from at least one product supply taken from a packing machine. The packing machine comprises at least one conveying device, at least one filling nozzle, at least one ventilation device with at least one ventilation valve and at least one ventilation nozzle on the product path between the product supply and at least one product outlet. The product outlet is provided in particular at the filler neck. By means of the conveyor bulk material is conveyed through at least one filler in the container. By means of a control unit, the venting valve is controlled so that the amount of air effectively passing through the venting nozzle in a period of time at the beginning of a filling operation is greater than in a period of time at the end of the filling process. The control unit starts the ventilation before filling.

The method according to the invention also has many advantages, since it enables effective and clean filling of bulk goods in containers.

Preferably, the amount of air in the time period at the beginning of a filling operation is at least 50% greater, and in particular at least twice as large as in the time period at the end of the filling process. In particular embodiments, the amount of air at the beginning of a filling process is at least four times as large as at the end of a filling operation. In preferred embodiments, the air is added through the vent valve during the entire filling process, at least as long as the shut-off valve is open. In the calming phase after the shutdown of the conveyor and / or after closing the shut-off device no air is supplied. The amount of air can be changed stepwise or continuously. The first period of time at the beginning does not have to start directly at the beginning of filling. The above-defined period of time at the end of the filling process may, but need not, end with the end of the filling. In particularly advantageous embodiments, the filling process comprises at least one coarse stream at the beginning and at least one fine stream at the end of the filling process. At the end of the fine flow, a waiting period may follow to reduce the overpressure present in containers.

In all cases and embodiments of the device and the Method, it is preferred that the filling process in addition to the filling itself still includes a section after filling and / or a section prior to filling. The section after filling can be used in particular for calming and / or pressure reduction in the container. The section before filling can be used in particular for preparatory measures. The section of the filling is in particular the section in which material is transported into the container and / or the section in which material is transported to the container and / or in which the conveyor is activated.

In all embodiments, it is possible and preferred that at least one index for a ratio of a weight increase within the coarse flow to an increase in weight within the fine flow is determined. In simple embodiments, the index corresponds to the ratio of the weight gradients in the coarse flow and in the fine flow. It is possible that the weight increase over a certain proportion of time of the coarse flow and over a certain proportion of time of the fine flow is determined. Within the respective time periods, an average or typical slope in the coarse flow and an average or typical slope in the fine flow are preferably determined.

The weight increases in the coarse flow and in the fine flow can be set alone and / or in relation to one another in order to determine a ratio or the characteristic number. The ratio or the key figure is saved. The following filling operation is preferably controlled in dependence on the stored data.

In preferred embodiments, the amount of air supplied in the time period at the beginning of the filling process is reduced when the weight increase within the coarse flow in the previous filling falls below a predetermined level. It has been found that with the supply of too much air, the inner bag pressure rises so fast that the material supply is reduced in the container. In addition, if too much air is supplied, the volume ratio of product to air changes Filling channel unfavorable.

Preferably, the amount of air in the period at the beginning of a subsequent filling operation is increased when the dead time at the beginning of the current filling operation exceeds a predetermined level. The dead time indicates the period of time until a weight increase of the container can be registered after the start of filling. This happens z. B. if the product is poorly ventilated or stale and thus flows poorly.

Furthermore, preferably in a subsequent filling operation, the supplied air quantity in a period of time at the beginning and the amount of air supplied in a period of time at the end adjusted when the ratio of the weight increases within the coarse flow and within the fine flow in the current filling process falls below a predetermined level. For a concrete cement, a value of four has been found to be suitable. This value may be different for other products. If too much air is supplied, no pronounced coarse flow and no pronounced fine flow interval can be determined in the course of the weight and the addition of air is subsequently reduced.

If the characteristic value exceeds a further predetermined value, it is preferable to increase the amount of air supplied in at least one time interval in order to avoid a blockage. If too little air is supplied, there is a threat of blockage due to bridging, for example.

The conveyor may comprise a Fülltopf and a conveyor turbine. Alternatively, as a conveying member, a pump, a screw or a gravity feed can be used. In all embodiments, at least one ventilation nozzle is provided, in which the amount of air is set more constant and / or even set constant and / or controlled differently. In such a case, a ventilation valve regulates the amount of air and a valve is used for constant basic ventilation.

For another aspect, it is the object of the invention to provide a packing machine and a method, which improved bottling is possible.

Such a packing machine is used to fill bulk goods in containers. The packaging machine comprises at least one product supply, at least one delivery device, at least one filler neck, at least one weighing unit, at least one control unit and at least one storage device. The control unit is designed and set up to store at least one characteristic of the course of the filling weight over the filling time in the storage device as historical data during a filling process. The control unit is designed and configured to control a subsequent filling operation as a function of the historical data stored in the storage device.

In particular, the historical data has been stored at least partially during a directly preceding filling process in the storage device. It is also possible for every second or every nth (n = 1,2,3 ...) filling process to store the characteristic of the course of the filling weight over the filling time in the storage device. The characteristic of the course of the filling weight can comprise all weight data determined. It is also possible that only individual data are stored in the memory device, which are characteristic and in particular representative of the filling process. For example, typical gradients, weight data, dead times and other time intervals or other data derived from the course of the weight can be stored in the memory device.

Preferably, at least one ventilation device is provided. The ventilation device comprises at least one ventilation valve and at least one ventilation nozzle. The venting nozzle is preferably provided on the product path between the product supply and at least one product outlet. Preferably, the ventilation valve is designed to be controllable via a control unit. In particular, the control unit and the venting valve are arranged and configured to effectively control the amount of air passing through the venting nozzle as a function of what is stored in the storage device control historical data.

The control unit is preferably designed and configured to control the conveyor in dependence on the historical data stored in the memory device.

The method according to this aspect of the object is for filling bulk goods in containers with a packing machine. The packaging machine has at least one product supply, at least one delivery device, at least one filler neck, at least one weighing unit, at least one control unit and at least one storage device. A filling process is controlled by the control unit. The control unit stores characteristic data obtained in the filling operation as historical data in the storage device. A subsequent filling operation is controlled by the control unit in dependence on the historical data stored in the storage device.

Such a packaging machine according to the invention and such a method according to the invention has many advantages. In a simple way, a self-adapting operating conditions adapting packing machine is provided. By determining the data and storage during operation, it is possible to respond quickly even with high and highest performance figures. Even if the fluidity decreases or increases, each reacts reliably. Downtimes can also be taken into account. Also on a material change is automatically reacted.

Fig. 1

eine perspektivische Ansicht einer erfindungsgemäßen Packmaschine zum Füllen von Ventilsäcken;

Fig. 2

eine schematische Draufsicht auf die Packmaschine nach Fig. 1;

Fig. 3

eine stark schematische Draufsicht auf die Packmaschine nach Fig. 1;

Fig. 4

einen stark schematischen Querschnitt durch einen Teil der Packmaschine nach Fig. 1;

Fig. 5

eine stark schematische perspektivische Ansicht eines Belüftungsventils;

Fig. 6

eine schematische Darstellung des Gewichtsverlaufs während eines Füllvorgangs; und

Fig. 7

eine schematische Darstellung eines Gewichtsverlaufs während eines folgenden Füllvorgangs.

Further advantages and features of the present invention will become apparent from the exemplary embodiments, which are explained below with reference to the attached figures:
In the figures show:

Fig. 1

a perspective view of a packing machine according to the invention for filling valve bags;

Fig. 2

a schematic plan view of the packing machine after Fig. 1 ;

Fig. 3

a highly schematic plan view of the packing machine after Fig. 1 ;

Fig. 4

a highly schematic cross section through a part of the packing machine after Fig. 1 ;

Fig. 5

a highly schematic perspective view of a vent valve;

Fig. 6

a schematic representation of the weight profile during a filling process; and

Fig. 7

a schematic representation of a weight course during a subsequent filling process.

In the Fig. 1 to 3 a packaging machine 1 is shown, which serves for filling bulk goods in container 3. In the packaging machine 1 valve bags are filled.

The packing machine 1 is designed to be rotatable and has a plurality of filling units 40. The number of filling nozzles 7 may vary depending on the configuration of the packing machine 1 and the intended use and the material to be filled and here be between about four and sixteen or more. However, a packing machine 1 according to the invention can also be designed as a fixed single-piece packing machine or as a row packer with a plurality of filling nozzles 7. All filler is here a total of a silo or a product supply 4 assigned.

Fig. 2 shows a plan view and Fig. 3 a schematic plan view of the packaging machine. 1

Each filling unit 40 of the rotatable packing machine Fig. 1 takes a slice of cake accordingly. The available space requirement of a segment 45 results from the angle 44. With 12 filling nozzles, this is 30 °. Each filling unit 40 has a filling pot 5, a filler neck 7, a bag chair 48 and here in each case a control unit 12. The packaging machine 1 is assigned here a Aufsteckeinrichtung 43 with a bag magazine 46. After attaching the container 3 during the filled continuous rotation. The packing machine 1 is driven by a motor 47 in the direction of rotation 52. After filling, the filled valve sacks 3 are removed by a discharge device 41. Each filling unit 40 may be associated with a single closing device 42, or a common closing device 42 is provided on the discharge device 41 in order to additionally weld the bag valves.

Fig. 4 shows a highly schematic cross-section of a portion of a packaging machine 1 according to the Fig. 1 to 3 , Above the Fülltopfes 5, the product supply 4 is shown schematically. The product path 9 is indicated schematically by arrows from the product supply 4 into the valve bag or the container 3. The bulk material 2 occurs at the end of the filler neck 7 through the product outlet 11 into the hanging on the filler neck 7 3 from. During the filling process, the container 3 is weighed with the bulk material 2 located therein in the gross method via a weighing unit 21.

In each case a conveyor turbine 6 is provided in the filling pots 5 here as conveying device 6, which also here rotates about a substantially horizontal axis so that the turbine blades of the conveyor turbine 6 transport the bulk material provided in the respective filling pot 5 into the filling channel 18. In other embodiments, the axis of rotation of the conveyor turbine 6 may be inclined or vertically aligned. In the filling channel 18, a shut-off device 22 is arranged. The shut-off device 22 is designed here as a metering device and can be spent on the actuating cylinder 22a in the shut-off position and in a fully open position for the coarse flow and in a partially open position for the fine flow. Also possible are even more positions to allow multiple coarse flows and / or fine streams.

In the upper region of the filling pot 5, a ventilation nozzle 26 is shown schematically, through which a controllable amount of air is supplied to the bulk material 2 in the filling pot 5. The air nozzle 26 is connected to a vent valve 8 for control. The vent valve 8 is controlled by a control unit 12, which in turn is connected to a memory device 50.

In the memory device 50 data 51 are stored during operation. Can be stored z. B. Measurement data recorded via various sensors during a filling process. Preferably, at least one index or characteristic value is also stored in the memory device 50. In particular, several key figures are stored, which are characteristic of the filling process.

Particularly suitable are measured values or derived key figures resulting from the course of weight during a filling process. Thus, the dead time determined from the course of the weight at the beginning of a filling process and the characteristic gradients of the course of the weight in the coarse stream and in the fine stream are particularly suitable for controlling subsequent filling operations.

In the filling channel 18 are here before the shut-off device 22 and then arranged ventilation nozzles 26, which are also supplied via the ventilation valve 8 and the control unit 12 controlled air. It is also possible that each separate ventilation valves 8 are provided. The ventilation valves 8 may be arranged directly on the ventilation nozzle 26. But it is also possible a central arrangement for each filling unit z. B. on the control unit associated with a filling unit. The ventilation nozzle 26 is then connected via a line to the vent valve 8. Time delays due to the volume of the line can be neglected.

Each filling pot 5 or each filler 7 is associated with a ventilation device 20. Each ventilation device 20 has at least one ventilation valve 8, to which at least one ventilation nozzle 26 is assigned in each case. The control of the ventilation valve 8 via a control unit 12, which can also control the filling process. In the control unit 12, a characteristic curve 19 is stored for the connected ventilation valves 8 in order to enable a proportional control. The weight data acquired by the weighing unit 21 are stored in the memory device 50. All measured data and / or the characteristic numbers 31 determined therefrom are stored in the memory device 50 saved. The measured data are evaluated with regard to the course of the filling weight in order to be able to adapt in particular the following filling process to the knowledge gained. Optionally, the control of the current filling process, for example, with respect to the waiting time at the end of the filling process is adjusted.

In addition to the shut-off device 22, the ventilation nozzle 26 via an annular ventilation channel 25 (see. Fig. 4 ) Add air to the bulk material 2.

The hanging on the filler neck 7 3 is filled by the product outlet 11 at the end of the filler neck 7. In the central region of the filling channel 18, a bag tester 49 is provided on the filler neck 7, which tests the presence of a bag before the start of filling.

Fig. 5 shows a schematic perspective view of a ventilation device 20, which comprises a controlled by the control unit 12 vent valve 8, an annular body 23 with a ventilation channel 25 and a vent 26 includes. The annular body 23 has a passage cross section 24, which is adapted to the inner cross section of the filling channel 18. The passage cross-section 24 is surrounded by the ventilation channel 25. Over the entire circumference of the annular ventilation duct 25, air is supplied to the bulk material 2. As a result, in particular, the wall friction is reduced.

6 and 7 show two successive filling operations 15a and 15b for the respective filling of cement as bulk material 2. In each case, the filling weight 36a, 36b applied over the filling time.

In both cases, each of the internal pressure 37a, 37b dotted in the container 3 with applied, although the internal pressure is not regularly detected with the packing machine 1 or must be detected. The pressure curves 37a and 37b serve to explain the principle and show that a control solely on the basis of the weight curves 36a, 36b is possible and leads to excellent results in the course of the filling operations. A pressure-dependent control during a filling process is not necessary. A pressure sensor on each filler neck is not required and can be saved.

First is in Fig. 6 a non-optimal filling process 15a shown here, which has a deliberately unfavorable filling curve to explain the principle.

At the beginning of the filling process 15a, the conveyor turbine 6 is operated at the intended operating speed. At the same time the shut-off device 22 is brought via the actuating cylinder 22a in the position for the coarse flow 27a, in which the complete filling channel 18 is released here. At the end of the coarse flow 27a, the shut-off device 22a is brought into the position for the fine flow 28a, in which, for example, half of the filling channel 18 is closed. The point in time for switching from the coarse flow 27a to the fine flow 28a may be, for example, the filled weight, for example 70%, 80% or 90% of the intended target weight.

The air quantity 13a, which is added here continuously during a complete time interval 14a at the beginning of the filling process 15a, is additionally shown. After the end of the period 14a, a reduced amount of air 17a is continuously supplied for the period 16a at the end of the filling operation 15a.

As is apparent from the relatively small dead time 34a at the beginning of the filling process, the amount of air supplied 13a at the beginning of the filling process 15a in any case sufficient for a sufficient fluidization of the bulk material 2 from. The dead time 34a indicates the period of time until an increase in weight of the container 3 can be registered.

At the in Fig. 6 shown curve of the filling weight 36a over time, the supplied amount of air 13a here in the period 14a is too large, so that the increase of the filling weight 36a during the coarse flow 27a is relatively low. This is because too much air has entered the container 3, so that the conveyor turbine 6 must work against the filling pressure in the container 3 and in the filling channel 18 too little material is promoted. That is why the average weight increase 32a in the coarse flow 27a or characteristic weight increase 32a in the coarse flow 27a relatively low, which increases the filling time. In addition, the internal pressure 37a in container 3, which is shown here by way of example, rises sharply and remains at a high level.

At the end of the period 14a, the supplied air amount 13a is reduced, so that an air amount 17a is supplied in the period 16a. The reduction of the amount of air from 13a to 17a, however, is relatively low, so that still a considerable proportion of air is still introduced into the container 3. As a result, the pitch of the filled fill weight 36a does not change significantly over time in the fine stream 28a. A difference of the gradients 32a and 33a is not clearly visible. This means that the ratio of the weight gradient 32a in the coarse flow 27a and the weight slope 33a in the fine flow 28a is relatively small.

Even in the fine flow 28a, the internal pressure 37a measured here by way of example remains at a high level and drops relatively little. At the end of the fine flow 28a there is still a considerable inner bag pressure 37a, so that a considerable waiting time has to be provided after the end of the time period 16a until the container can be removed. Even at the normally scheduled acceptance time 10a, there is still a relatively high internal pressure 37a which could still lead to contamination of the environment of the packing machine 1. Therefore, when measuring a weight curve 36a, as in Fig. 6 is shown, the waiting time after the end of the fine flow 28a until a bag 3 is removed, still increased dynamically, to safely avoid pollution of the environment. Here, the bag 3 is removed only at the time 10 a 'instead of the time 10 a. The waiting time until the acceptance is z. B. increased by a certain percentage when a in Fig. 6 shown weight curve 36a is determined.

The course of the filling weight 36a over time is evaluated even further during the filling process 15a or even thereafter. In particular, the dead time 34a and other characteristic Gradient values for the weight gradient 32a in the coarse flow and the weight gradient 33a in the fine flow are derived as characteristic numbers 31 from the determined course of the filling weight 36a. At least the key figures 31 (34a, 23a, 33a) are stored as data 51 in the memory device 50. It is also possible to store all measurement data or a part of it.

The low ratio of the gradients 32a to 33a in the case of the filling process 15a here is a clear sign that too much air has been added to fill the cement. An ideal curve depends on the bulk material to be filled.

Since the ratio of the slopes 32a to 33a is smaller than desired, a changed control profile 29b is provided for the following filling operation 15b. In any case, one of the air quantities 13b, 17b is changed in order to optimize the filling curve. Here, the time duration for the first time interval 14b is reduced and the second time interval 16b is adapted. Furthermore, both air quantities 13b and 17b are reduced here. In particular, the ratio of the amount of air 13b to the amount of air 17b is considerably increased. The total amount of air supplied (area below the air volume curve) is thereby significantly reduced.

Fig. 7 shows a representation of the filling operation 15b over time, wherein also the filling weight 36b is plotted over time. Here, too, for information purposes, the internal pressure 37b in the container 3 with applied. The knowledge of the internal pressure is for controlling the amount of air 13b, 17b but not necessary.

It can clearly be seen that the weight gradient 32b in the coarse flow 27b is significantly greater than the weight slope 33b in the fine flow 28b. The region of the coarse flow 27b and the region of the fine flow 28b are optically clearly distinguishable. Due to the shallower slope in the fine flow 28b and the weight accuracy is improved. Furthermore, the total filling time 30b is considerably less than the filling time 30a in the filling process 15a according to FIG Fig. 6 ,

It is essential, above all, that at the time of acceptance 10b already a very low internal pressure prevails 37b in the container, so that a Pollution of the environment is significantly reduced. At the same time, however, the filling time 30b is not increased, but can be significantly reduced compared to the filling time 30a.

This is due to various factors. The amount of air 13b in the period 14b at the beginning of the filling operation 15b is opposite to the amount of air 13a Fig. 6 slightly reduced. In addition, the length of the time interval 14b is considerably reduced, so that the total amount of air added within the time interval 14b is considerably smaller than the total amount of air added in the filling process 15a within the time interval 14a Fig. 6 , Furthermore, in the in Fig. 7 illustrated filling process 15b the amount of air 13b considerably reduced in the period 16b at the end of the filling process 15b than in the filling process 15a according to Fig. 6 , In the filling operation 15b, the air amount 17b is set to 1/3 or 1/4 of the air amount 13b in the period 14b. The transition from the amount of air 13b to the amount of air 17b can also be continuous. By these measures, much less air is introduced into the bag than in the filling process 15a according to Fig. 6 , This leads to a considerably flatter pressure curve of the internal pressure 37b in the container 3. In the filling process 15b, even at the end of the fine flow 28b, the internal pressure 37b in the container 3 is lower than at the intended acceptance time 10a during the filling process 15a Fig. 6 , As a result, after a shorter waiting time at the time of acceptance 10b, the internal pressure 37b has further decreased. At the time of acceptance 10b, the discharge of bulk material 2 from the interior of the container 3 to the outside can be reliably prevented.

As a result, the cleanliness of the packing machine 1 and its environment can be significantly increased. A use of pressure sensors is not necessary, since based on the weight profile of the filling weight 36a, 36b can be deduced over time to the existing internal pressure without having to measure the internal pressures this.

In the 6 and 7 illustrated courses of the internal pressures 37a, 37b are therefore illustrative. The pressure sensors are not necessary part of the packing machine 1.

It has been found that a ratio of the weight increase 32 in the coarse flow 27 to the weight increase 33 in the fine flow 28 of more than three and in particular more than four leads to advantageous filling operations. Therefore, depending on the actual weight curves 36a, 36b, the amounts of air 13, 17 and, if appropriate, the durations of the corresponding intervals 14, 16 are adjusted in order to subsequently obtain better adapted filling curves. When adjusting not only the directly preceding each filling process can be considered, but it can also be several previous filling operations z. B. be considered equal or differently weighted.

Overall, the cleanliness of the system can be greatly increased. At the same time even the filling time can be reduced.

Another advantage is that even under unfavorable starting conditions or even ambient conditions, it is automatically possible to react to the changing bulk material conditions and to the changing flow behavior and to react. If the packing machine 1 or one of the filler neck 7 has stood for example for several hours or days until further filling takes place and, for example, low outside temperatures are present, the flow behavior at this filler neck 7 is improved by adding more air at the beginning of a filling process. After the filling of some containers 3, the addition of air is automatically reduced, since on the basis of the evaluation of the filling weight over time an automatic adjustment takes place. LIST OF REFERENCE NUMBERS 1 packing machine 25 ventilation duct 2 bulk goods 26 ventilation nozzle 3 container 27a, 27b coarse flow 4 Product supply, silo 28a, 28b fine flow 5 Fülltopf 29a, 29b control profile 6 conveyor turbine 30a, 30b filling 7 filling 31 Ratio, ratio 8th vent valve 32a, 32b weight slope 9 product path 33a, 33b weight slope 10a, 10b Time of collection 34a, 34b dead 11 product output 36a, 36b Filling 12 control unit 37a, 37b internal pressure 13a, 13b air flow 40 filling unit 14a, 14b period 41 discharging device 15a, 15b filling 42 closing 16a, 16b period 43 Aufsteckeinrichtung 17a, 17b air flow 44 angle 18 filling channel 45 segment 19 curve 46 bag magazine 20 aerator 47 drive 21 weighing unit 48 bag chair 22 shut-off 49 sack tester 22a actuating cylinder 50 memory device 23 body 51 dates 24 Passage cross-section 52 direction of rotation 60 Conveyor

Claims (13)

1. Packaging machine (1) for filling bulk material (2) into packages (3) comprising at least one product supply (4), at least one filling box and at least one conveyor device (60) comprising a conveyor turbine, a pump or a conveyor screw, having at least one filling spout (7), at least one aeration device (20) having at least one air valve (8) and at least one aeration nozzle (26) in the product travel path (9) between the product supply (4) and at least one product outlet (11), wherein the air valve (8) is configured to be controlled by means of a control unit (12) and the control unit (12) and the air valve (8) are set up and configured for controlled adjustment of the air volume (13) effectively passing through the aeration nozzle (26) in a plurality of steps and wherein a characteristic curve (19) of the air valve (8) is stored in the control unit (12), characterized in that the control unit (12) and the air valve (8) are set up and configured to adjust the air volume (13) effectively passing through the aeration nozzle (26) to be larger in a time phase (14) at the beginning of a filling process (15) than in a time phase (16) at the end of the filling process (15) and that the control unit (12) is configured and set up to start aeration prior to the start of filling.
2. The packaging machine (1) according to the preceding claim wherein at least one characteristic of the curve of the filled weight (36) over the filling time is stored as historical data (51) in a memory device (50) and wherein the control unit (12) is configured and set up to vary controlling of the air valve (8) in a subsequent filling process in dependence on the historical data (51).
3. The packaging machine (1) according to claim 1 or 2 wherein the air valve (8) is configured as a proportional valve.
4. The packaging machine (1) according to any of the preceding claims wherein the control unit (12) is set up and configured to adjust the effective aeration cross section of the air valve (8) by way of at least one pulse width modulation method.
5. The packaging machine (1) according to any of the preceding claims wherein the filling spout (7) has a weighing unit (21) assigned to it for capturing a measure of a weight of the associated package (3).
6. The packaging machine (1) according to any of the preceding claims wherein the aeration nozzle (8) is provided at the filling duct (18) between the conveyor device (60) and the product outlet (11) of the filling spout (7) and/or wherein the aeration nozzle (8) comprises an annular body (23) having an internal flow section (24) and at least one aeration duct (25) surrounding at least part of the flow section (24).
7. The packaging machine (1) according to any of the preceding claims wherein at least two aeration devices (20) are provided and/or wherein at least one aeration device (20) having at least two aeration nozzles (8) is provided.
8. The packaging machine (1) according to any of the preceding claims wherein the control unit (12) is set up and configured to control the air volume (13) through the air valve (8) in dependence on at least one parameter which parameter is taken from a group of parameters comprising the filled weight (36), the elapsed filling time, a measured or estimated fill height in the package, the bulk material temperature, the ambient temperature, the bulk material moistness, the ambient humidity, the elapsed idle time of the packaging machine, the type of bulk material (2) intended for bagging, and other measurement values of the bulk material (2) intended for bagging and historical data (51) of at least one filling process in the past.
9. The packaging machine (1) according to any of the preceding claims wherein the control unit (12) is configured and set up to cause adaptation of a controlling profile (29) for a subsequent filling process when the filling time (30) of a preceding filling process varies by a predetermined measure.
10. Method for filling bulk material (2) into packages (3) comprising a filling process (15) on a packaging machine (1) wherein the packaging machine (1) comprises at least one product supply (4), at least one filling box and at least one conveyor device (60) comprising a conveyor turbine, a pump or a conveyor screw, furthermore comprising at least one filling spout (7), at least one aeration device (20) having at least one air valve (8) and at least one aeration nozzle (26) in the product travel path (9) between the product supply (4) and at least one product outlet (11), wherein a control unit (12) controls the air valve (8) to provide controlled adjustment of the air volume (13) effectively passing through the aeration nozzle (8) in a plurality of steps, and that a characteristic curve (19) of the air valve (8) is stored in the control unit (12) wherein the characteristic curve (19) is taken into account for controlling, characterized in that the control unit (12) and the air valve (8) adjust the air volume (13) effectively passing through the aeration nozzle (26) to be larger in a time phase (14) at the beginning of a filling process (15) than in a time phase (16) at the end of the filling process (15), and that the control unit (12) starts aeration prior to the start of filling.
11. The method according to the preceding claim wherein a characteristic number (31) is obtained for a ratio of a weight gradient (32) within the high speed flow (27) to a weight gradient (33) within the low speed flow (28).
12. The method according to any of the two preceding claims wherein a dead time (34) is determined at the beginning of a filling process.
13. The method according to any of the two preceding claims wherein the air volume (13) of a subsequent filling process (15) is increased in at least one time phase (14, 16) if during at least one preceding filling process the characteristic number (31) has dropped beneath a predetermined measure and/or when the dead time (34) has extended beyond a predetermined time interval.

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