Cleaning arrangement with a material storage container for conveyor technology and cleaning processes

Abstract

Cleaning arrangement for cleaning a material storage container (2) for conveyor technology with a material storage container (2) which can be pressurized, a print media source (52), at least one nozzle device (62, 78, 100) arranged or arrangable in the container for supplying a pressurized medium from the pressure media source (52) into the interior of the container (2), a separation device (46), a connecting line (44) that connects the interior of the container to the separating device (46), a shut-off device (40) for closing and opening the connection through the connecting line (44) between the container (2) and the separating device (46), wherein the shut-off device is designed to open the closed connection even when a pressure differential is present, in particular when there is an overpressure above atmospheric pressure on the container side, and a control device (84) for controlled opening and closing of the shut-off device, wherein the control device is designed to close the shut-off device and, after the build-up of pressure within the container by the medium flowing in through the at least one nozzle device (62, 78, 100), to open the shut-off device (40) in particular abruptly, wherein the or at least one of the nozzle assemblies (62, 78, 100) is mounted to rotate or pivot, and / or wherein the or at least one of the nozzle assemblies (62, 78, 100) has a flow guide device, wherein an airflow passed by the flow guide device causes the nozzle assembly and / or the medium in the container to rotate.

Description

[0001] The invention relates to a cleaning arrangement for dry cleaning of a material storage container and a cleaning method for this purpose.

[0002] DE 20 2010 005 875 U discloses a material storage container for conveying technology which has various design features that reduce the formation of gaps or dead volumes, so that a CIP wet cleaning process ('Cleaning In Place') can be carried out with a significantly reduced risk of residues remaining.

[0003] DE 39 00 664 C2 proposes a dry cleaning process for feed containers in which a container is placed under vacuum and ambient air flows into the container through a tangential inlet connection in such a way that a cyclone forms inside the container. This airflow effectively removes particles adhering to the wall and transports them towards the vacuum source.

[0004] In DE 10 2011 112 016 B3, a metering screw with an upstream storage container is blown out by pressurizing it with air. Compressed air nozzles are arranged on the lid of the storage container and blow compressed air towards the inner wall of the container. To prevent contamination of downstream components, the normal discharge opening of the metering screw is closed by means of a valve, and a secondary opening is opened for the discharge of the contaminants to be removed.

[0005] US 5,478,406 A discloses a material transport and storage container that is cleaned using a bag cleaner. The container is elastic and can be inflated and deflated by evacuation. Inflation and evacuation of the container are performed by a cyclone vacuum cleaner, whose suction and pressure sides can be alternately connected to the container via a changeover valve. The changeover valve alternately evacuates air from the cyclone vacuum cleaner or blows it into the container. During the evacuation phase, the pressure side of the cyclone vacuum cleaner opens to the outside, while during inflation of the container, the suction line of the cyclone vacuum cleaner opens to the atmosphere.

[0006] The object of the invention is to provide a cleaning arrangement with a material storage container for conveyor technology and a cleaning method in which efficient dry cleaning is possible.

[0007] This problem is solved by the features of claims 1, 2, 12 and 15. Advantageous embodiments are the subject of dependent claims.

[0008] Nowadays, the aim is to clean conveying systems, especially their material storage containers, without having to disassemble the system into individual parts and clean each one separately. This so-called CIP (Cleaning in Place) process is typically carried out by circulating a cleaning fluid through the conveying system. The cleaning fluid removes deposits of the conveyed material (such as powder or granules) and other contaminants through chemical and / or mechanical action. This so-called wet cleaning method has the disadvantage that, on the one hand, it generates large quantities of contaminated fluid that must be collected and, if necessary, purified for reuse. On the other hand, the disposal and purchase of new cleaning fluid incurs high costs.On the other hand, residual liquid remains within the conveying system, which must be removed by heating, a time-consuming and costly process. These disadvantages are eliminated by the dry cleaning methods using compressed air mentioned above. However, these methods have the drawback that stubborn layers of material or contaminants are not effectively removed in certain hard-to-reach areas of the conveying system. For example, the lid of a material storage container is a preferred deposition site for contaminants that are difficult to access. The effectiveness of the dry cleaning methods described above is limited by the fact that the flow rate of a compressed air stream is restricted (or expensive due to the cost of compressed air generation) and, furthermore, critical deposition areas for contaminants are insufficiently supplied with compressed air.

[0009] When the term "contaminants" is used here and in the following, it refers not only to foreign bodies but also to deposits of the material being conveyed. Material deposits can constitute "contamination" if, for example, a material change is required in the conveying system and the previously used material contaminates the subsequent material. Alternatively, a batch change might involve the use of a newer material with a limited shelf life, meaning the previous material becomes contaminated due to its expiration date (e.g., milk powder, food powder, or similar products). Contamination can also result from changes in the material's consistency. For instance, a normally powdery material might form a layer as a deposit, which then ceases to be powdery and becomes flaky, thus contaminating the powdered material.

[0010] According to the invention, it is proposed that in the cleaning arrangement according to claim 1 or the method according to claim 12, the material storage container for the conveying system be pressurized with compressed air and the internal pressure in the container be allowed to rise above atmospheric pressure, so that when the excess pressure is released, contaminant material is carried away in a surge. Here, at least the material storage container can be pressurized. The sudden or rapid release of the medium from the container generates a high gas flow that abruptly carries away the contaminants detached from the walls, or, by the accelerated flow passing over the walls, additional contaminants are detached from the walls. Due to the mass flow of the medium triggered by the excess pressure, the removal of the contaminants is very effective.

[0011] The cleaning medium is gaseous and can be any type of purified (dry and oil-free) gas. Preferably, the medium is purified compressed air, which is cost-effective. Hereinafter, the gaseous medium will also be referred to as "compressed air," although the medium is only limited to compressed air in specific cases.

[0012] In the cleaning arrangement according to claim 2 or in the method according to claim 15, the creation of overpressure is largely avoided, so that the material storage container or the conveying system does not need to be designed for and certified for compressed air. To achieve sufficient material transport for removing the contaminant, the contaminant is blown off or agitated by means of the pressurized medium, which is blown towards the inner wall of the container through at least one nozzle assembly. Simultaneously, ambient air is admitted into the interior of the container via an air supply device. Preferably, the ambient air constitutes the main mass flow, while the media flow merely agitates the contaminant. Thus, ambient air is used as an efficient transport medium to carry away the agitated contaminants.

[0013] Unless otherwise specified, the following descriptions apply to both types of cleaning arrangements (according to claim 1 and claim 2, respectively). The individual configurations are applicable without restriction, either individually or in combination with other configurations, to the methods. Conversely, the control device according to claim 1 and claim 2 is designed to implement all method variants or functional features, either individually or in combination, by appropriately controlling the control device.

[0014] The gaseous, pressurized medium is particularly advantageous as the conveying medium, which is already used as the conveying medium in the conveying system in which the material storage container is used.

[0015] The shut-off device can be located at the outlet of the material storage container, on or in the connecting line, or on or in the separating device, so that the shut-off device can completely block the flow of media from the container to the separating device. The shut-off device can also be used in the largely pressureless cleaning system, for example, to close a cleaning line when the material storage container in the conveying system is used for the intended delivery of material to be conveyed and the connection to the separating device needs to be closed.

[0016] The shut-off device can be a simple switching device, toggling between 100% blockage and complete opening (where technically feasible). Alternatively, the shut-off device can be controlled in intermediate positions, partially blocking or partially opening the passage. For example, in setups with only slight overpressure, the shut-off device can be used to throttle the flow of ambient air and / or pressurized medium towards the separator. For instance, with active extraction from the separator, the volume flow towards the separator can be throttled.

[0017] The term "material storage container" is used here, but this can also be referred to as a vessel, or one of the material containers together with a section of the conveying line can be collectively referred to as a "container." If, for example, the shut-off device is located directly upstream of the separation device, the connecting line is also subjected to the pressure cycle or dry cleaning cycle.

[0018] Advantageously, the cleaning arrangement features multiple nozzle units, each of which can be supplied with the pressurized medium separately (for example, by inserting a valve between each nozzle unit and the pressurized medium source), so that the pressurized medium is introduced into the container via only one of the nozzle units at a time. This increases the efficiency of spraying the container's inner wall with the pressurized medium, as a pressure jet can then be generated at higher pressure by each nozzle unit. In this case, the nozzle units can be supplied with pressurized medium successively and at different times.

[0019] In the pressurized cleaning arrangement, the pressure is preferably released from the container when the shut-off device is open, while no pressurized medium is supplied through the nozzle assembly. Conversely, pressurized medium is introduced through the nozzle assembly while the shut-off device is closed. However, it can also be provided (for example, for initial pre-cleaning) that pressure is introduced through one or more nozzle assemblies while the shut-off device is still open.

[0020] Advantageously, outside air is supplied through the air supply system via a tangential or inclined inlet into the interior of the container, creating a vortex or cyclone within the container. This vortex, in addition to the effect of the jet nozzles, sweeps across the inner walls of the container, thus increasing the effectiveness of contaminant removal. Vortex or cyclone formation also works in rectangular containers, as a vortex can generally be created within these shapes, or, in the case of containers with a rectangular cross-section, the corners are usually rounded. Alternatively or additionally, the supplied outside air is directed towards the container ceiling by the air supply system, so that the contaminants suspended by the compressed air jet(s) are immediately carried away in the incoming airflow.In this embodiment, instead of or in addition to the tangential entry of the outside air through the air supply device, an airflow can also be directed against the upper inner wall or inner wall of the lid of the container in order to achieve, as with the tangential entry, the most complete possible air exchange between the dust cloud detached by means of the pressure medium and the outside or fresh air.

[0021] Advantageously, the outlet from the container to the separation device is located at a lower point or in the lower part of the container, so that the flow of contaminants within the container is directed from top to bottom. This reduces the required airflow volume, as the material does not have to be lifted against gravity.

[0022] The at least one nozzle assembly preferably comprises multi-hole nozzles and / or one or more slot nozzles, each producing a compressed air jet with a defined jet direction. Advantageously, in stationary nozzle assemblies, the nozzles are oriented such that the media jet impacts the inner wall of the container perpendicularly or nearly perpendicularly, thus optimizing the mechanical effect of removing contaminants. Similarly, in movable nozzle assemblies, the nozzles are preferably oriented so that the pressure jet impacts the surface perpendicularly or at an acute angle to the surface normal for at least most of the time.

[0023] By blowing the contaminants off the inner wall of the container, the contaminants are dispersed in a dust cloud within the pressurized medium and / or the ambient air and transformed into a form that can be easily transported away by means of a gaseous stream. Preferably, in the version with the pressurized container, the material within the volume of the container is compressed by building up pressure and thereby also compacted for transport.

[0024] Particularly advantageous is the repeated cleaning cycle with pressure build-up and / or intermittent inflow of the pressure medium through the nozzle device, so that the impurities are diluted and removed by the multiple rinsing effect.

[0025] Exemplary embodiments of the invention are explained in more detail below with reference to the figures. The figures show: Fig. 1A a side view of a material container for conveyor technology, Fig. 1B A top view of the material container with various connections and installed components, Fig. 1C a cross-sectional view of the material container from the side, Fig. 2 a schematic cross-sectional view of the material container with installed compressed air inlet system according to a first embodiment, Fig. 3 a schematic cross-sectional view of the material container with installed compressed air inlet system according to a second embodiment, Fig. 4. A block diagram of elements used by a control unit during drying rinsing. Fig. 5. A time / pressure diagram for overpressure flushing. Fig. 6. A time / pressure diagram for atmospheric purging, Fig. 7 a schematic representation of the angle of pressure application to the surface normal, Fig. 8 a spherical rotator, and Fig. 9 a spray head with multiple swivel arm.

[0026] The Fig. Figures 1A to 1C show a conveying container 2 as known from DE 20 2010 005 875 U in side view, top view, and cross-section. The conveying container is composed of a side wall 4, which is welded all around to a container lid 10, and a container base 6. The lid 10 is rounded, e.g., in a dished shape, or alternatively, is designed as a basket bottom, hemisphere, or similar. The container base 6 and the side wall 4 form a conical surface or a funnel surface that tapers downwards and transitions into a bend 8. The bulk material stored in the conveying container 2 is conveyed through the bend 8 to a transport line of the conveying system (not shown). The container base 6 and the side wall 4 are connected to each other by means of a clamping ring 12. Brackets 13 are welded to the upper part of the side wall 4, by means of which the container 2 rests on vertical columns 14.The welds (between cone 4 and cover 10, or on the block flange hereinafter referred to as "the" weld) to or on the interior are free of gaps and dead spaces. The surface roughness of the inner walls and the welds meets hygiene requirements.

[0027] Fig. Figure 1B shows a top view of the transmitter container 2. A filling valve 16 is located in the center of the container lid 10. When open, the filling valve 16 provides a filling passage 17 to the interior of the container. The filling valve 16 is driven by a motor / gearbox unit 18. Another opening on the container lid 10 is covered and closed by a blind flange 20. The container lid 10 has additional flanges 40 with openings to which the following flanged components are attached: a pressure relief or safety valve 22, connection ports 24 and 26, a vent valve 30 with a motor / gearbox unit 32, a level sensor 34, and a pressure sensor 36.

[0028] Fig. Figure 1C shows a cross-sectional view of the transmitter container 2 along the in Fig. Section line A - A shown in 1B. As can be seen, inside the sending container 2 a ventilation candle 28 is welded to the connection nozzle 26, with which compressed air is blown into the area of ​​the lower cone tip to dissolve plugs or blockages of the conveyed material to be transported downwards.

[0029] Fig. Figure 2 shows a schematic cross-sectional view of the container during a dry cleaning phase. The filling valve 16 is removed, and in its place, the filling passage is closed with a flushing lid 58, which is connected to a compressed air inlet system according to a first embodiment. A shut-off or outlet valve 40 is arranged between the container bottom 6 and the elbow 8. The outlet valve 40 can be opened and closed by means of a motor, the actuator 42. A conveying section 44, which is, for example, a section of the conveying section used for material transport, connects to the elbow 8. A suction device 46 (also referred to herein as a separation device) is connected to the conveying section 44, with which contaminants are filtered from the airflow (su). In the illustrated example, the suction device has a dust container 48 and a suction blower 50 (also referred to herein as an extraction device).

[0030] In this configuration, the valve 40 can be opened abruptly or quickly, even if there is an overpressure relative to atmospheric pressure on the side of the container 2 and / or a slight underpressure on the outlet side due to the suction device 46. Instead of the position shown, the valve 40 can also be located at a different point along the conveying section 44 or at the suction device 46. Instead of providing the connection to the suction device wholly or partially via the conveying section 44, the section 44 can also be a completely separate connection (with respect to the conveying section that the container 2 supplies with material during normal operation) to the suction device. In this case, the usual conveying section is then closed off from the container 2 to allow pressure build-up and to prevent the transfer of contaminants into the conveying section. However, if the conveying section 44 is part of the cleaning section, it is also cleaned by the container rinsing process.

[0031] The flushing cover 58 is fitted airtight and pressure-tight onto the passage 17, and a supply line 54 delivers compressed air from a compressed air supply 52. ​​Advantageously, the compressed air supply is the source that provides the compressed air for material handling during a material handling process. This compressed air source already provides dry, oil-free compressed air with a sufficient flow rate for the dry flushing process, thus making the medium available for dry flushing at minimal cost.

[0032] A valve 56 allows the compressed air supply 52 to be controlled and either supplied or shut off. A spacer tube 60 is arranged on the inside of the lid 58, extending into the interior of the container 2. A swivel arm 62 is rotatably mounted at the lower end of this spacer tube. The swivel arm 62 has several fine nozzles (not shown) from which jets of pressure 64 emerge when compressed air is supplied. The nozzles point in different directions along the surface of the swivel arm, so that jets of pressure are emitted in various directions. At the end of the spray arm, one or more nozzles with a tangential component with respect to the axis of rotation (which here coincides with the spacer tube 60) are arranged, so that the recoil of the jet(s) of pressure causes the swivel arm to rotate. As it rotates, the jets of pressure sweep across different areas of the inner wall of the container.In particular, the nozzles are also directed upwards towards the inner wall of the lid, so that dust and impurities are blown away from the inside of the lid.

[0033] In the design of dry cleaning according to Fig. 2. Container 2 can be pressurized above atmospheric pressure. For example, with an overpressure of at least 400 mbar, 600 mbar, 1 bar, 2 bar, 3 bar, 4 bar, 5 bar, or 6 bar. To dry clean container 2, all material is first removed so that the container is 'empty'. If the rinsing lid 58 with the swivel arm 62 is not permanently installed even during the conveying processes, the filling valve 16 is removed, for example, and the rinsing lid 58 is fitted, for which the swivel arm 62 is inserted into the interior of the container. The extraction system 46 is activated, and container 2 is placed under slight negative pressure (interval from in Fig. 5) Then valve 40 is closed (and possibly a valve to the actual material conveying line, if this is not line 44).

[0034] Opening valve 56 allows compressed air to flow into the interior of the container, causing the swivel arm to rotate. As it rotates, the incoming pressure jets 64 blow away residues and contaminants from various areas of the inner wall. The pressure / time diagram for this cleaning process is shown below. Fig. As shown in Figure 5, after the valve 40 closes, the pressure rises (interval bc) and exceeds atmospheric pressure (dashed horizontal line). At time c, the valve 40 opens abruptly and the valve 56 closes. The overpressure is released in a surge towards the suction port 46, carrying the contaminants loosened by the pressure jets 64 towards the suction port 46. Due to the overpressure, a considerable mass of air is available to transport the contaminants, resulting in a high air velocity and high flow rate in section 44. This minimizes deposits and effectively flushes away contaminants. This is advantageous, for example, if section 44 is part of the conveying line intended for cleaning.

[0035] What's next in Fig. As shown in Figure 5, during period cd, the system is aspirated, so that a slight negative pressure is restored in the container. At time d, valve 40 is closed and valve 56 is opened to repeat the drying rinse process. As before, the incoming pressure jets 64 create overpressure, and any remaining residues / contaminants are blown off. At time e, valve 40 is opened again and valve 56 is closed. The surge-like rinsing process is repeated. These cycles can be repeated more than twice, for example, three times, four times, five times, or more. The number of cycles can also be controlled based on the success rate (su).

[0036] Since a strong air movement is generated during the sudden release of excess pressure towards the outlet (valve 40 / bend), little or no pressure jets need to be applied to the lower part of the container, and the pressure jets can be concentrated in the upper part. In this embodiment, valve 56 can remain open even when valve 40 is open.

[0037] Fig. Figure 3 shows a schematic cross-sectional view of the container 2 with an installed compressed air inlet system according to a second embodiment. This arrangement and the associated method can be used for containers 2 or conveying systems that are not designed for overpressure. Here, the container 2 has ventilation openings for introducing ambient air during the drying process. In the illustrated example, the ventilation openings are two lines 70 inserted tangentially on the outside of the lid 10. With the valves 72 open and the suction 46 running, ambient air flows into the container, and the tangential inflow creates a cyclone 74 inside the container, which helically extends down the inner wall of the container to the bend 8.Alternatively or additionally, outside air is blown from inside the container towards the container lid through a pipe (not shown) and an associated valve to support the pressure jets 80 and to remove the stirred-up dust.

[0038] Three supply lines 54a, b, c pass through the flushing lid 58, each of which is connected to the compressed air supply 52 via an associated valve 56a, b, c. Inside the container 2, the supply lines 54a, b, c continue as angled lines 76a, b, c, which extend into the interior and are guided at different angles to different side regions of the container 2. A rotatably mounted ball head 78 is arranged at the end of each of the angled lines 76a, b, c. The ball head 78 (see Figure 1) Fig. 8) has several arcuate slot nozzles 94 around its circumference and one slot nozzle 96 at the end opposite the rotary bearing 92. The arcuate nozzles 94 generate a pressure jet 80 with a tangential component, causing the ball heads 78 to rotate when compressed air is applied via lines 76a, b, c. This rotation causes the pressure jets 80 to sweep over a large area of ​​the inner wall of the container. Due to the spatial distribution of the ball heads, the areas covered by the pressure jets 80 overlap, so that the upper area of ​​the inner wall of the container is completely covered by pressure jets.

[0039] Fig. Figure 6 shows an example of the pressure profile during a dry cleaning cycle of the arrangement of Fig. 3. Valve 40 remains open throughout the entire cleaning process (it can, for example, be omitted entirely). If section 44 is not the usual conveying section or part thereof, the conveying section is closed during cleaning. At time k, the extraction system 46 is activated, creating a slight negative pressure. At time 1, valves 56a, b, c, and 72 are opened, allowing compressed air and ambient air to flow into the container. This creates a slight positive pressure and activates the cyclone 74. The slight positive pressure can be, for example, a maximum of 50 mbar, 100 mbar, 200 mbar, or 400 mbar. The dust blown up by the pressure jets 80 is effectively transported by the cyclone towards the extraction system. At time m, valves 56a, b, c, and 72 are closed, and the extraction system creates a slight negative pressure. Here, too, the slight pressure variation creates minor pressure surges that assist the removal process with the cyclone.Here too, the drying rinse is preferably repeated cyclically. Here, cycle mno corresponds to cycle klm.

[0040] In this embodiment, either only one of the valves 56a, b, c is opened at a time-staggered interval, or only one of the valves 56a, b, c is opened in each cycle. The advantage of opening only one of the valves 56a, b, c is that by introducing the air through only one of the ball heads 78, the pressure increase inside the container is lower and / or a higher volume of compressed air passes through that one ball head, so that with higher pressure (i.e., with a stronger pressure jet 80), the contaminants in the vicinity of the currently operated ball head 78 can be blown off more effectively.

[0041] Of course, this can also be done when arranging... Fig. 2 instead of the spacer tube 60 and the swivel arm 62 the arrangement of Fig. 3 with the three valves 56 a, b, c, the three angled pipes 46 a, b, c and the three ball heads 78. Likewise, in the arrangement of Fig. 3 instead of the three ball heads 78 the swivel arm 62 the Fig. 2 with the corresponding connection port. In general, when using several nozzles that can be supplied with compressed air separately via separate valves 56 a, b, c, the compressed air can be injected through the respective nozzle at staggered times, so that the duration of the dry cleaning cycle is extended, but a higher cleaning effect is achieved due to the higher pressure or flow rate of the pressure jet (64 / 80).

[0042] Fig. Figure 4 schematically shows a block diagram of a control unit 84, which controls the dry cleaning cycle for the arrangement according to Fig. 2 or Fig. 3 controls. Both arrangements are shown here as examples - for instance, both valve 56, which is used in the arrangement of Fig. 2 is used, as well as valves 72 and 56 a, b, c, which are used in the arrangement of Fig. 3 will be used.

[0043] The air pressure inside container 2 can be measured using the pressure sensor 36 described above. If the dry cleaning cycle is not controlled exclusively by using specific durations (predefined time intervals), errors may occur during the process. Fig. In the cycle shown in Figure 5, for example, time b is determined by the pressure dropping to a specific value below atmospheric pressure due to the suction effect of the extraction unit 46. Then, valve 40 is closed and valve 56 is opened, allowing compressed air to flow into container 2 and the pressure to rise until, at time c, pressure measurement determines that the overpressure reaches or exceeds a predetermined value (see above – for example, 2 bar absolute). Once this pressure value is reached, valve 40 is opened and valve 56 is closed. This cycle can be repeated as described above.

[0044] The control unit 84 can also determine the number of drying cycles based on the progress of the cleaning process. For this purpose, a photoreflector 86 is arranged, for example, on the container 2 and / or a photoreflector is located in the connecting section 44. A light beam is directed into the container 2 or the line of the conveyor section 44 by the photoreflector 86, 88, and a reflection signal is measured. A high reflection signal indicates a high dust content within the container or line 44, thus suggesting a high degree of contamination. Conversely, a low reflection indicates that little dust or contaminants are currently being stirred up, which—depending on the phase of the cleaning cycle—indicates a good cleaning result.

[0045] At the in Fig. In the cleaning cycle shown in Figure 5, for example, it can be measured inside the container shortly before times c or e whether a high proportion of dust is stirred up if contaminants are present. If, on the other hand, only a low proportion of dust is detected at these times, it can be concluded that cleaning has already been sufficiently carried out. Using sensor 88, however, the following can be measured during the cycle: Fig. The air is measured at intervals of cd and ef, respectively, to determine whether the air being transported towards extraction 46 carries a high dust content. The control unit 84 can compare the measurement signal with a threshold value and initiate a new dry cleaning cycle if the measurement signal exceeds the threshold.

[0046] At the in Fig. The dry cleaning cycle shown in Figure 6 is also measured by sensor 86 shortly before times m and o, while due to the open valve 70, sensor 88 is also used to measure at or around times m and o to determine whether further dry cleaning cycles are required.

[0047] Fig. Figure 7 schematically shows the side view of the positions of nozzles 90 and 90a relative to a section of the container wall—here, a section of the container lid 10. At nozzle 90, the pressure jet 64, or rather its axis, is aligned parallel to the surface normal of the surface area exposed to compressed air. That is, the pressure jet 64 from nozzle 90 strikes the surface section perpendicularly. At nozzle 90a, the central axis of the pressure jet 64 is at an angle α to the surface normal. It was surprisingly found that the best cleaning effect is achieved with a pressure jet 64 when the jet is directed perpendicular to, or at a limited, small angle relative to, the surface normal. Preferably, the jet angle is within a range of ±5°, 10°, 20°, 30°, or 40° to the surface normal to achieve good cleaning performance with the pressure jet.Furthermore, it was determined that the distance between the nozzle exit and the surface area to be cleaned should be a maximum of 40 cm, 30 cm, 20 cm, 15 cm.

[0048] Fig. Figure 9 shows a side view of another swivel arm, designed here as a multi-swivel arm 100. A main arm 104 is rotatably mounted on a pivot bearing 102, with compressed air being introduced into the main arm 104 through the pivot bearing 102. Within the main arm 104, the compressed air is directed to the secondary arms 106, which are rotatably mounted on the main arm 104. Both the secondary arms 106 and the main arm 104 are equipped with several outlet nozzles (not shown), through which a jet of compressed air is expelled. At least one nozzle on the main arm 104 is oriented such that it has a tangential component with respect to the axis of rotation (pivot bearing 102), so that the recoil of the compressed air jet sets the main arm 104 into rotation. The same applies to the secondary arms 106, so that when compressed air is applied, both the main arm and the secondary arms rotate. This results in a wide and evenly distributed coating of the inner container walls with compressed air.

[0049] As mentioned above, the nozzle arrangements can be as shown in Fig. 2, Fig. 3, Fig. 8 and Fig. 9 shown, remain permanently in container 2, or are installed inside the container exclusively during dry cleaning cycles. When arranging Fig. 3 a wing element or baffle plate can be provided on the ball head 78, on the main arm 104 or on the swivel arm 62, for example, so that the rotary motion is not generated due to a tangential component of a pressure jet, but by the rotary motion of the cyclone 74, which is generated due to the tangential inflow through the tangential inlet 70 inside the container. Reference symbol list: 2 transmission containers 4 side wall 6 Container bottom 7 Floor wall 8 manifolds 10 container lids 12 clamping ring 13 console 14th pillar 16 Filling valve 17 Filling cycle 18 Motor / gearbox unit 20 Blind flange 22 Overpressure / safety valve 24, 26 connection spigots 28 Ventilation candle 30 Vent valve 32 Motor / gearbox unit 34 level indicators 36 Pressure sensor 40 Exhaust valve 42 Drive 44 Conveyor section 46 Extraction 48 dust containers 50 suction blowers 52 Compressed air supply 54, 54a, b, c Supply line 56, 56a, b, c Valve 58 flush lids 60 spacer tube 62 Swivel arm 64 Pressure jet 70 Tangential inlet 72 valve 74 Cyclone 76a, b, c Angled cable 78 Ball head 80 jet pressure 84 Control unit 86, 88 Photoreflector 90, 90 nozzle 92 swivel bearings 94 radial slots 96 head slots 100 multi-swivel arms 102 swivel bearings 104 Main arm 106 Side arm α angle

Claims

[1] Cleaning arrangement for cleaning a material storage container (2) for conveyor technology with a material storage container (2) which can be pressurized, a print media source (52), at least one nozzle device (62, 78, 100) arranged or arrangable in the container for supplying a pressurized medium from the pressure media source (52) into the interior of the container (2), a separation device (46), a connecting line (44) that connects the interior of the container to the separating device (46), a shut-off device (40) for closing and opening the connection through the connecting line (44) between the container (2) and the separating device (46), wherein the shut-off device is designed to open the closed connection even when a pressure differential is present, in particular when there is an overpressure above atmospheric pressure on the container side, and a control device (84) for controlled opening and closing of the shut-off device, wherein the control device is designed to close the shut-off device and, after the build-up of pressure within the container by the medium flowing in through the at least one nozzle device (62, 78, 100), to open the shut-off device (40) in particular abruptly, wherein the or at least one of the nozzle assemblies (62, 78, 100) is mounted to rotate or pivot, and / or wherein the or at least one of the nozzle assemblies (62, 78, 100) has a flow guide device, wherein an airflow passed by the flow guide device causes the nozzle assembly and / or the medium in the container to rotate. [2] Cleaning arrangement for cleaning a material storage container (2) for conveyor technology with a material storage container (2), a print media source (52), at least one nozzle device (62, 78, 100) arranged or arrangable in the container for supplying a pressurized medium from the pressure media source (52) into the interior of the container (2), each of the valves (56, 56a, b, c) in the supply line (54, 54a, b, c) between each of the nozzle assemblies (62, 78, 100) and the pressure media source (52), a separation device (46), a connecting line (44) that connects the interior of the container to the separating device (46), at least one air supply device (70, 72) for controlled supply of air into the interior of the container, a control device (84) for controlled opening and closing of the at least one air supply device (70, 72) and the at least one valve (56, 56a, b, c). [3] Cleaning arrangement according to claim 2, wherein the control device is designed to open the air supply device (70, 72) and the at least one valve at least temporarily simultaneously and / or wherein the air supply by means of the at least one air supply device is tangential to the container wall and / or is directed towards the container ceiling. [4] Cleaning arrangement according to claim 1, 2 or 3 wherein the control device (84) is designed to supply the medium from the print media source (52) controlled by the at least one nozzle device (62, 78, 100), and / or wherein at least one valve (56, 56a, b, c) is arranged between the pressure media source (52) and the at least one nozzle assembly (62, 78, 100). [5] Cleaning arrangement according to any one of claims 1 to 4, wherein the nozzle assembly, at least one of the nozzle assemblies or all nozzle assemblies (62, 78, 100) is aimed at an inner container wall is aligned at an angle of 0°, max. 10°, 20°, 30° or 45° to the surface normal of the wall section under load. [6] Cleaning arrangement according to one of claims 1 to 5, wherein the or at least one of the nozzle assemblies (62, 78, 100) is rotatably mounted and has at least one nozzle which is oriented with respect to the axis of rotation (60, 92, 102) such that the recoil of the media flow exiting the nozzle causes the nozzle assembly to rotate. [7] Cleaning arrangement according to one of claims 1 to 6, wherein the connecting line (44) and / or the shut-off device (40) on the underside of the container (2) connects the container to the separating device (46). [8] Cleaning arrangement according to one of claims 1 to 7, wherein the separation device (46) comprises a suction device (50) and / or a filter (48). [9] Cleaning arrangement according to one of claims 1 to 8, wherein the at least one nozzle arrangement (62, 78, 100) has at least one slot nozzle or is a multi-hole nozzle. [10] Cleaning arrangement according to one of claims 1 to 9, with a contamination sensor (86, 88), wherein the control device (84) receives a signal from the sensor (86, 88) and repeats a cleaning cycle depending on the sensor signal. [11] Cleaning arrangement according to one of claims 1 to 10, with a pressure sensor (36), wherein the control device (84) receives a signal from the pressure sensor and controls the supply of the medium from the pressure media source (52) and / or the air supply device (70, 72) and / or the shut-off device (40) depending on the pressure signal. [12] Method for dry cleaning a material storage container (2), wherein a gaseous medium can be introduced into the container at pressure by means of at least one nozzle device (62, 78, 100) and the container can be shut off at the outlet side by means of a shut-off device (40), wherein after opening the shut-off device the medium in the container flows to a separation device (46), wherein the method comprises: Closing the container (2) by closing the shut-off device (40), Building up overpressure in the container (2) by allowing the medium to flow into the container through the at least one nozzle device (62, 78, 100), rapid opening of the shut-off device (40), so that the medium inside the container empties in a surge towards the separating device (46), wherein the or at least one of the nozzle assemblies (62, 78, 100) is mounted to rotate or pivot, and / or wherein the or at least one of the nozzle assemblies (62, 78, 100) has a flow guide device, wherein an airflow passed by the flow guide device causes the nozzle assembly and / or the medium in the container to rotate. [13] Method according to claim 12, wherein the overpressure is at least 200 mbar, 400 mbar, 700 mbar, 1 bar, 1.5 bar, 3 bar or 4 bar above atmospheric pressure. [14] Method according to claim 12 or 13, comprising: repeating the process of closing the container, building up overpressure and gushing out the container. [15] Method for dry cleaning a material storage container (2), wherein a gaseous medium can be introduced into the container at pressure by means of at least one nozzle device (62, 78, 100) and outside air can be supplied into the container by means of at least one air supply device (70, 72), wherein the method comprises: Allowing outside air to flow in through at least one air supply device and at least temporarily during the flow of outside air, introducing the gaseous medium, or Introducing the gaseous medium and, at least temporarily during the introduction, allowing outside air to flow in through at least one air supply device. [16] Method according to claim 15, wherein air / medium is extracted from the container by means of a separating device during the inflow and introduction process.

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