Self-cleaning pressure loading system

Abstract

The invention relates to a pressure loading system (1) comprising a pressure loading tank (20) having a longitudinal axis (A), which has a pressure container wall (22) with an inner surface (24) bounding a cavity (26) and which has an inlet section (12), a central section (14) and an outlet section (16) along the longitudinal axis (A), comprising a particle inlet (10) which defines an inlet opening (28) in the inlet section (12), and a particle outlet (18) which defines an outlet opening (30) in the outlet section (16), and comprising a gas supply line (44) opening into the cavity (26) in the inlet section (12), which is configured to introduce a gas stream (2) into the cavity (26), in such a manner that the gas stream (2) in the cavity (26) is set into rotation about the longitudinal axis (A).

Description

[0001] Self-cleaning pressure loading system

[0002] The invention relates to a pressure loading system comprising a pressure loading tank having a longitudinal axis, a pressure vessel wall with an inner surface circumscribing a cavity, and an inlet section, a center section, and an outlet section along the longitudinal axis, with a particle inlet defining an inlet opening in the inlet section, and a particle outlet defining an outlet opening in the outlet section. The invention also relates to a method for cleaning a pressure loading tank having a longitudinal axis, a pressure vessel wall with an inner surface circumscribing a cavity, and an inlet section, a center section, and an outlet section along the longitudinal axis.

[0003] The background to the present invention is the pre-expansion of expandable particles using infrared radiation. In contrast to steam pre-expansion, this so-called dry expansion offers the possibility of rapid material changeover, since the system can be cleaned relatively quickly. This type of pre-expansion is interesting for particles that do not themselves contain a blowing agent, such as EPP. To enable pre-expansion with such particles, an increased internal pressure of the particles is required instead of the blowing agent. For this purpose, the particles are loaded with a pressurized gas in the pressure loading system. This takes place in a process or pressure loading tank in which the gas pressure is slowly increased after the particles have been introduced. This can take place with simultaneous heating of the tank interior or without heating. Depending on other factors, the process without heating takes on the order of days.If heat is added, the process can take place within a few hours. The loaded particles are then either transferred to a storage tank or stored in the process tank, where a constant, elevated pressure prevails so that the particles can be kept for an extended period. For further processing, the particles are transported to a pre-expander. Transport should be relatively fast to prevent the pressure in the particles from dissipating. For this purpose, transport can also take place in a transport line under elevated pressure directly to the pre-expansion system. In the dry pre-expansion device, the particles are heated by infrared radiation and expand to a predetermined amount due to the increased internal pressure. One problem with such expandable particles is that they tend to adhere to the inner surface of the pressure vessel wall.As a result, particles can remain in the pressure loading tank after emptying. This is particularly problematic before each material change. The remaining particles can become clearly visible as foreign bodies in the finished foamed product, for example, in the case of a material change involving a color change or when switching to particles with different dimensions or properties. For this reason, the pressure loading tank must be cleaned before each material change.

[0004] Cleaning is traditionally carried out using cleaning lances, which are inserted through a cleaning opening in the pressure loading tank. Gas is injected into the tank under high pressure through the lances, which are manually guided to remove particles from as many areas of the interior surface as possible.

[0005] It should be added that the invention is not limited to applications in which the pre-foaming of expandable particles is carried out using infrared radiation. This technology was mentioned at the beginning because it provided the impetus for the present invention. However, the invention can also be combined, for example, with subsequent steam pre-foaming. Against this background, the task is to largely automate the cleaning process in general.

[0006] The object is achieved by a pressure loading system according to patent claim 1 and by a method according to patent claim 20.

[0007] The invention provides that in a pressure loading system of the type mentioned at the outset, a gas supply is provided which opens into the cavity in the inlet section and is designed to introduce a gas flow, preferably an air flow, into the cavity in such a way that the gas flow in the cavity is set into rotation about the longitudinal axis.

[0008] The method according to the invention accordingly comprises the step of introducing a gas stream into the cavity in the inlet section, wherein the gas stream in the cavity is set into rotation about the longitudinal axis.

[0009] The invention takes advantage of the geometry of the pressure loading tank by providing a gas supply that is arranged and configured relative to the pressure vessel wall, preferably in a stationary manner, such that the gas flow moves along the inner surface, rotating about the longitudinal axis, from the inlet section to the outlet section, passing at high relative speed along the largest possible surface area of ​​the inner surface. A pressure loading system is understood here in particular to mean a system that is designed to provide gas at a sufficient pressure. Accordingly, a pressure loading tank is understood to be a tank that has sufficient pressure resistance. Currently, maximum pressures of 6 to 10 bar are common. Wherever reference is made to "pressure" or information is given in this regard, this refers to the overpressure relative to atmospheric or air pressure.With regard to even larger particle volumes, much higher pressures of up to 50 bar or more may be used in the future. At the very least, however, the pressure loading system should be designed to provide gas at a pressure of at least 1 bar, preferably at least 3 bar, and the pressure loading tank should accordingly have a pressure resistance of at least 1 bar, preferably at least 3 bar. In order to be able to withstand such pressures while simultaneously maintaining a container volume of 200 liters or more, which is sufficient for production scales, container wall thicknesses of preferably at least 5 mm, particularly preferably at least 8 mm, should be provided. Alternatively and / or in addition to high wall thicknesses, stiffening elements such as beads, false walls, bands running circumferentially along the container wall, or ribs running longitudinally along the container wall, and the like are preferably considered.

[0010] Preferably, the pressure loading tank has a maximum internal cross-sectional area in the center section perpendicular to the longitudinal axis. In other words, the pressure loading tank is thickest in the center section.

[0011] Furthermore, the central section is preferably cylindrical. From a manufacturing perspective, a circular cylindrical shape is particularly preferred.

[0012] The inlet section advantageously has an inner cross-sectional area perpendicular to the longitudinal axis, which continuously increases along the longitudinal axis from the inlet opening to the center section. In other words, the inlet section advantageously widens in a funnel shape along the longitudinal axis from the inlet opening to the center section. A particularly preferred embodiment of the funnel-shaped inlet section provides a conical widening.

[0013] Accordingly, the outlet section preferably has an inner cross-sectional area perpendicular to the longitudinal axis, which continuously decreases along the longitudinal axis from the center section to the outlet opening. In other words, the outlet section preferably tapers along the longitudinal axis from the center section to the outlet opening in a funnel shape or, again in a particularly preferred embodiment, in a conical shape. A cylindrical center section, as well as a conically widening inlet section and a conically tapering outlet section, are preferred for manufacturing reasons, since these simple geometries can be manufactured using simple tools and blanks from sheet metal material.

[0014] It is also advantageous that the inner surface in the inlet section has a maximum funnel opening angle ß e 45°, preferably ß es 35°, plotted against the longitudinal axis. Larger funnel opening angles mean that the cavity in the inlet section expands too quickly. The gas flow introduced into the cavity is therefore not sufficiently deflected in a tangential direction relative to the longitudinal axis, which has an adverse effect on the formation of a rotary flow. Furthermore, the inner surface in the inlet section preferably has a minimal funnel opening angle ß. e > 20 °, preferably ß e > 25°, plotted relative to the longitudinal axis. A small hopper opening angle excessively limits the volume of the pressure loading tank for a given length.

[0015] Also preferably, the inner surface in the outlet section has a maximum funnel opening angle ß a 45°, preferably ß as 25°, plotted against the longitudinal axis. Similar considerations apply here as for the inlet section, although the maximum funnel opening angle in the outlet section can preferably be designed somewhat more acutely, thus taking into account the weakening of the gas flow caused by wall friction toward the outlet section.

[0016] The maximum hopper opening angle is defined as the largest angle formed by a tangent in a radial plane to the inner surface of the inlet or outlet section, plotted between the inner vessel wall and the longitudinal axis. In the case of a conical taper or flare, the maximum hopper opening angle corresponds to the constant hopper opening angle in the radial plane.

[0017] It is preferred that the outlet section tapers more sharply along the longitudinal axis than the inlet section widens along the longitudinal axis. In other words, it is preferred if the maximum funnel opening angle ß a in the outlet section and the maximum funnel opening angle ß e in the inlet section have the following relation ß a < ß e . Particularly preferred is ß a < ß e and especially preferred is ß a < ß e -3°.

[0018] A weakening of the gas flow from the inlet section to the outlet section can thus be compensated for relatively well. It has been found that the best cleaning results can be achieved when the gas supply opens into the inlet section through the inlet opening. Alternatively, the gas supply can also open into the inlet section tangentially in the direction from the inlet section to the outlet section below the inlet opening with respect to the longitudinal axis. In this case, it is preferred if the gas supply has at least two or more openings into the inlet section. Gas supply through the inlet opening of the particle inlet has the advantage that the gas flow already flows through the particle inlet on the same path as the particles to be filled in, so that any residues in this area can also be captured and entrained by the gas flow.

[0019] This embodiment can be particularly preferably implemented by having the gas supply system comprise a gas guide element arranged at least partially within the particle inlet. The gas flow is set into rotation by means of the gas guide element.

[0020] For this purpose, the gas guide element advantageously has at least two gas guide vanes arranged symmetrically around the longitudinal axis.

[0021] The particle inlet is preferably designed as a nozzle coaxial with the longitudinal axis. In this case, the gas guide vanes advantageously extend radially from the longitudinal axis to an inner surface of the particle inlet, forming a vane outer edge along the inner surface of the particle inlet that is inclined at least in sections relative to the direction of the longitudinal axis. This geometry results in a vane shape that imposes a tangential motion component on the inflowing gas.

[0022] Particularly preferably, the outer blade edge forms a curved curve with an increasing angle of inclination relative to the longitudinal axis in the direction from the inlet opening to the outlet opening. A gas guide element with gas guide vanes configured in this way has proven advantageous over gas guide vanes with a straight outer blade edge with regard to improved deflection of the gas flow in the circumferential direction.

[0023] Most preferably, the angle of inclination of the blade outer edge at its outlet-side end in the axial direction relative to the direction of the longitudinal axis is 30° or more, particularly preferably 40° or more, and most preferably 45° or more.

[0024] In combination with one or more of the above-mentioned features, the pressure loading system is advantageously further developed in that the ratio of the cross-sectional area of ​​the inlet opening and the maximum internal cross-sectional area is > 1.5:100. Likewise, a geometry of the pressure loading tank is preferably further developed in such a way that the ratio of the square root of the maximum internal cross-sectional area to a length of the pressure loading tank along the longitudinal axis from the inlet opening to the outlet opening is 0.2 < F max / \_ < 0.8.

[0025] A particularly advantageous embodiment of the pressure loading system provides that a shear stress of at least 1 Pa, preferably at least 5 Pa and particularly preferably at least 10 Pa, can be generated by means of the rotating gas flow over an area proportion of at least 80%, preferably at least 85%, particularly preferably at least 90% of the inner surface and at a distance of 1 mm from the inner surface.

[0026] Accordingly, the method according to the invention is advantageously further developed in such a way that a shear stress of at least 1 Pa, preferably at least 5 Pa and particularly preferably at least 10 Pa, is generated by means of the rotating gas flow over an area proportion of at least 80%, preferably at least 85%, particularly preferably at least 90% of the inner surface and a distance of 1 mm from the inner surface.

[0027] The method is further advantageously further developed in that the cavity has a volume V and the inner surface has a dimension F, wherein the gas stream, preferably an air stream, is introduced under an inlet pressure P of 3 to 12 bar, preferably 6 to 10 bar, and / or a mass flow S of 20 to 100 kg / s. The gas stream is preferably introduced under these conditions for at least 0.5 seconds, particularly preferably at least 1 second, and / or for at most 5 seconds, particularly preferably at most 3 seconds.

[0028] Accordingly, the pressure loading system advantageously comprises a gas pressure source, preferably a compressed air source, connectable to the gas supply of the gas loading tank, which is configured to provide an air flow at an inlet pressure P of 3 to 12 bar, preferably 6 to 10 bar. Here, too, the overpressure relative to atmospheric or air pressure is meant. Furthermore, the gas pressure source is preferably configured to provide a gas flow with a mass flow S of 20 to 100 kg / s. These values ​​have proven advantageous for generating the above shear stress values ​​in most cases.

[0029] Preferably, the gas pressure source is configured to provide the gas flow for at least 0.5 seconds, particularly preferably at least 1 second. It has been shown that this duration is generally sufficient to completely empty the tank and remove any adhering particles. Furthermore, the gas pressure source is preferably configured to provide the gas flow for a maximum of 30 seconds, preferably a maximum of 5 seconds, particularly preferably a maximum of 3 seconds. This allows gas consumption and thus the dimensions of the gas pressure source to be limited.

[0030] In a preferred embodiment, the gas pressure source comprises a discontinuous gas pressure source, such as a gas pressure accumulator, in particular a compressed air accumulator. Gas pressure accumulators or discontinuous gas pressure sources in general have the advantage of being able to provide a large mass flow at a simultaneously high pressure. At the same time, the gas pressure accumulator can be charged with a comparatively low volume or mass flow because cleaning is only repeated at long intervals. Therefore, a small, inexpensive compressor is usually sufficient.

[0031] Alternatively, a continuous gas pressure source, such as a blower, can be used as a compressed air source. This can also generate a large mass flow relatively inexpensively. However, the pressures that can be generated are comparatively low, so the cleaning process can take longer.

[0032] With discontinuous gas pressure sources, the provision of the gas flow can be limited in time, for example, simply by dimensioning the gas pressure reservoir. Continuous gas pressure sources can be switched on or off as needed. Regardless of the type of gas pressure source, the pressure loading system preferably includes a switching element for switchably interrupting the air flow. Such a switching element can be implemented, for example, as a valve arrangement, flap arrangement, or the like.

[0033] The method further preferably provides for the gas loading tank to be grounded. Accordingly, the gas loading tank has an electrical ground connection. This allows the number of adhering particles and thus the need for cleaning to be reduced from the outset.

[0034] The method is advantageously further developed in that the introduction of a gas stream into the cavity comprises the introduction of an ionized gas, in particular ionized air. Accordingly, the pressure loading system advantageously comprises a gas or air ionizer connected to the gas supply.

[0035] Further advantages and features of the invention are explained below using examples shown in the figures. They show:

[0036] Fig. 1 shows the pressure loading system according to the invention according to a first embodiment in a sectional side view; Fig. 2 shows a gas guide element in a perspective view, as installed in the pressure loading system according to Fig. 1;

[0037] Fig. 3 the gas guide element in side view;

[0038] Fig. 4 shows the pressure loading system according to Fig. 1 in a schematic representation with the flow pattern of an introduced gas stream drawn in;

[0039] Fig. 5 shows a second embodiment of the pressure loading system according to the invention in a sectional side view;

[0040] Fig. 6 shows a third embodiment of the pressure loading system according to the invention in a sectional side view;

[0041] Fig.7 shows a fourth embodiment of the pressure loading system according to the invention in the

[0042] Side view with modified gas supply and

[0043] Fig.8 shows a fifth embodiment of the pressure loading system according to the invention in the

[0044] Side view with modified particle inlet.

[0045] Figure 1 shows a first embodiment of the pressure loading system 1 according to the invention. This system has a longitudinal axis A. All components described below are designed to be substantially rotationally or rotationally symmetrical around this axis. These are, in the direction of flow of the gas stream, indicated by arrow 2, a particle inlet 10, an inlet section 12, a center section 14, an outlet section 16, and a particle outlet 18. Not shown are, for example, inspection windows or feedthrough windows for any probes for process monitoring and the like, which can also be arranged laterally on one of the aforementioned sections, inlets, or outlets and thus cancel the rotational or rotational symmetry."Essentially" is to be understood here as meaning that the embodiments in particular as well as the invention in general in this sense also extend to pressure loading systems whose pressure loading tank has a rotationally or rotationally symmetrical basic shape, but which is not completely rotationally or rotationally symmetrical due to connections and functional attachments or fittings.

[0046] The inlet section 12, the central section 14, and the outlet section 16 together form a pressure loading tank 20 with a common pressure vessel wall 22, the inner surface 24 of which defines a cavity 26. The particle inlet 10 and the particle outlet 18 are each designed as a nozzle coaxial with the longitudinal axis A. The particle inlet 10 defines an inlet opening 28 in the inlet section 12. Similarly, the particle outlet 18 defines an outlet opening 30 in the outlet section 16. The particles to be pressurized are introduced into the pressure loading tank 22 through the particle inlet, and the pressure-loaded particles are withdrawn from the pressure loading tank 22 through the particle outlet.

[0047] The pressure loading tank 20 has a maximum internal cross-sectional area 32 in the central section 14 perpendicular to the longitudinal axis A. Since, in this exemplary embodiment, the central section 14 has a circular-cylindrical geometry over its entire length, the cross-sectional area 32 is constant over its entire length. The inlet section 12 has an internal cross-sectional area perpendicular to the longitudinal axis A, which continuously increases along the longitudinal axis A from the inlet opening 28 to the central section 14. In the present case, the inlet section 12 specifically widens conically along the longitudinal axis A from the inlet opening 28 to the central section. In a mirror image of this, the outlet section 16 has an internal cross-sectional area perpendicular to the longitudinal axis A, which continuously decreases along the longitudinal axis A from the central section 14 to the outlet opening 30.Specifically, in the illustrated initial example, the outlet section 16 also tapers conically along the longitudinal axis A from the center section 14 to the outlet opening 30. Accordingly, the inner surface 24 in the inlet section 12 can be characterized by a constant funnel opening angle ß. e which spans between the longitudinal axis A and the inner surface 24. The same applies to the outlet section 16, whose inner surface 24, plotted against the longitudinal axis A, has a constant funnel opening angle ß a In the present embodiment shown in Fig. 1, the funnel opening angle ß e of the inlet section 12 and the funnel opening angle ß a of the outlet section 16.

[0048] A gas guide element 34 is arranged in the particle inlet 10, which will be explained in more detail below with reference to Figures 2 and 3. The gas guide element 34 is part of a gas supply, which, in addition to the gas guide element, can also have, for example, a gas feedthrough, a gas connection for a gas line and / or a valve for limiting the pressure and / or the volume flow of the gas flow (not shown). In the exemplary embodiment shown, the gas supply opens through the inlet opening 28 in the inlet section 12 into the cavity 26 of the pressure loading tank 20. The particles to be introduced into the pressure loading tank 22 through the particle inlet are transported through the gas guide element. This ensures that the gas travels the same path as the particles during the subsequent cleaning process before reaching the cavity 26, so that the cleaning process also partially covers their transport path.2 and 3 show an enlarged view of the gas guide element 34. In the exemplary embodiment according to FIG. 1, it is arranged completely within the particle inlet 10. However, it can also be arranged offset in the direction of the gas flow 2, i.e. downwards, projecting into the inlet section 12. Local prepositions such as “below,” “under,” “above,” or “above” refer herein to the direction of gravity, which in the exemplary embodiments shown here coincides with the flow direction of the gas flow 2. The gas guide element 34 has a total of six gas guide vanes 36 arranged rotationally or axially symmetrically around the longitudinal axis A. The gas guide vanes 36 extend in the radial direction R from the longitudinal axis A to the inner surface of the particle inlet 10, wherein they form a vane outer edge 38 along this inner surface of the particle inlet 10, which outer edge 38 is inclined at least in sections with respect to the direction A.More precisely, in the embodiment of the gas guide element 34 shown here, the blade outer edge 38 forms a curved curve with an inclination angle a relative to the direction of the longitudinal axis A that increases in the direction from the inlet opening 28 to the outlet opening 30, wherein the angle a defines the acute angle to the tangent to the curved curve of the blade outer edge 38, plotted relative to the longitudinal axis A. At its outlet-side end 40 in the axial direction, the maximum inclination angle is a. ma x relative to the direction of the longitudinal axis A in the embodiment shown here is 50°. The outlet-side or lower end 40 of the blade outer edge 38 is arranged in the plane of the inlet opening 28 in the initial example of Fig. 1.

[0049] Fig. 4 shows the result of a mathematical simulation of the pressure loading system 1 according to the embodiment of Fig. 1. A gas stream 2 introduced into the cavity 26 through the gas supply in the inlet section 12 is set into rotation about the longitudinal axis A in the cavity 26 by means of the gas guide element 34 arranged in the particle inlet 10. This is indicated in the simulation by means of spiral flow lines 42. The simulation showed that in this embodiment, a shear stress of at least 10 Pa can be generated by means of the rotating gas stream over an area proportion of > 80% of the inner surface 24, at a distance of 1 mm from the inner surface 24.

[0050] Fig. 5 shows a second embodiment of the pressure loading system according to the invention, which differs from the first embodiment according to Fig. 1 essentially in that the inlet section 12 and the outlet section 16 each have a different geometry, which also changes the overall geometry of the pressure vessel wall 22, the cavity 26 and the inner surface 24. In detail, the inlet section 12 and the outlet section 16 are still truncated cones, whereby in this case the maximum funnel opening angles of the inlet and outlet sections 12, 16 ß e = 30° and ß a = 20° or ß a = ß e- 10°. A simulation of the flow pattern within the cavity 26 in this example showed that, due to the optimized geometry, a shear stress of at least 10 Pa can be generated at a distance of 1 mm from the inner surface 24 by means of the gas flow, which is otherwise set in rotation in the same way, over an area of ​​> 90% of the inner surface 24.

[0051] Fig. 6 shows a third embodiment of the pressure loading system 1 according to the invention, which differs from the second embodiment of Fig. 5 essentially in that the inlet section 12, the central section 14 and the outlet section 16 are no longer described by simple straight contours, i.e., conical and cylindrical shapes, but by more complex curved profiles. In detail, the inner cross-sectional area of ​​the inlet section 12 continues to increase continuously along the longitudinal axis A from the inlet opening 28 to the central section 14, but now in a general manner, referred to herein as "funnel-shaped." Likewise, the inner cross-sectional area of ​​the outlet section 16 continues to taper continuously and generally in a funnel shape along the longitudinal axis A from the central section 14 to the outlet opening 30. Here, too, the inner surface 24 in the inlet section 12 has a maximum funnel opening angle ß e< 30°, plotted against the longitudinal axis (A), and the inner surface 24 in the outlet section 16 has a maximum funnel opening angle ß a < 20°. The maximum funnel opening angle ß e and ß a are each formed by the angles between the tangent in a radial plane to the contour of the inner cross-sectional area at the point of greatest cross-sectional increase or decrease (or mathematically the largest or smallest derivative of the curve) and the longitudinal axis A.

[0052] The central section 14 is further arranged between the inlet section 12 and the outlet section 16, with the boundary between the inlet section 12 and the central section 14, on the one hand, and the central section 14 and the outlet section 16, on the other hand, both lying in a region between the points of greatest cross-sectional increase and cross-sectional decrease. In this example, too, the pressure loading tank 20 has its maximum internal cross-sectional area 32 in the central section 14 perpendicular to the longitudinal axis A.

[0053] Unlike in previously shown embodiments, the gas guide element 34 here projects slightly downwards beyond the inlet opening 28 into the inlet section, but is nevertheless located at least partially and even predominantly in the particle inlet 10.

[0054] Fig. 7 shows a fourth exemplary embodiment of the pressure loading system 1 according to the invention, which differs from the second exemplary embodiment in Fig. 5 only by a modified gas supply 44. This opens into the cavity 26 in the inlet section 12 tangentially to the funnel-shaped pressure vessel wall 22 here. The opening is arranged almost directly below the inlet opening to ensure that the rotating gas flow almost completely flushes the cavity 26 of the pressure loading tank 20. In this case, the rotation is brought about by the tangential introduction and the internal redirection of the gas flow along the circular cone-shaped inlet section 12. Fig. 8 shows a fifth exemplary embodiment of the pressure loading system 1 according to the invention, which differs from the second exemplary embodiment in Fig. 5 by a modified particle inlet 50.This opens into the inlet section 12 not axially, but with a radial directional component perpendicular to the here funnel-shaped pressure vessel wall 22 into the cavity 26. The gas supply is again axial, as in the exemplary embodiments 1 to 3, and the rotation is again effected by the gas guide element 34.

[0055] It is understood that the invention also encompasses further combinations and variants of modified particle inlets and gas feeds.

[0056] Reference symbol

[0057] 1 pressure loading system

[0058] 2 Gas flow, arrow

[0059] 10 Particle inlet

[0060] 12 Inlet section

[0061] 14 Central section

[0062] 16 Outlet section

[0063] 18 Particle outlet

[0064] 20 pressure loading tank

[0065] 22 Pressure vessel wall

[0066] 24 Interior surface

[0067] 26 cavity

[0068] 28 Inlet opening

[0069] 30 Outlet opening

[0070] 32 maximum internal cross-sectional area

[0071] 34 Gas guide element

[0072] 36 gas guide vanes

[0073] 38 Blade outer edge

[0074] 40 outlet end (of the gas guide vane)

[0075] 42 Gas flow / arrow

[0076] 44 Gas supply

[0077] 50 particle inlet

[0078] A Longitudinal axis

[0079] R radial direction a m ax maximum inclination angle ß a Funnel opening angle of the outlet section ß e Funnel opening angle of the inlet section

Claims

Patent claims 1. Pressure loading system (1) with a pressure loading tank (20) having a longitudinal axis (A), a pressure vessel wall (22) with an inner surface (24) circumscribing a cavity (26), and having an inlet section (12), a center section (14), and an outlet section (16) along the longitudinal axis (A), with a particle inlet (10) defining an inlet opening (28) in the inlet section (12), and a particle outlet (18) defining an outlet opening (30) in the outlet section (16), characterized by a gas supply (44) opening into the cavity (26) in the inlet section (12), which is configured to introduce a gas stream (2) into the cavity (26) in such a way that the gas stream (2) is set into rotation about the longitudinal axis (A) in the cavity (26).

2. Pressure loading system (1) according to claim 1, characterized in that the pressure loading tank (20) has a maximum internal cross-sectional area (32) in the central section (14) perpendicular to the longitudinal axis (A).

3. Pressure loading system (1) according to one of the preceding claims, characterized in that the central section (14) is cylindrical.

4. Pressure loading system (1) according to one of the preceding claims, characterized in that the inlet section (12) has an inner cross-sectional area perpendicular to the longitudinal axis (A) which increases continuously along the longitudinal axis (A) from the inlet opening (28) to the central section (14).

5. Pressure loading system (1) according to one of the preceding claims, characterized in that the inlet section (12) widens in a funnel-shaped or conical manner along the longitudinal axis (A) from the inlet opening (28) to the central section (14).

6. Pressure loading system (1) according to one of the preceding claims, characterized in that the outlet section (16) has an inner cross-sectional area perpendicular to the longitudinal axis (A) which continuously decreases along the longitudinal axis (A) from the central section (14) to the outlet opening (30).

7. Pressure loading system (1) according to one of the preceding claims, characterized in that the outlet section (16) tapers in a funnel-shaped or conical manner along the longitudinal axis (A) from the central section (14) to the outlet opening (30).

8. Pressure loading system (1) according to one of claims 4 or 5 and according to one of claims 6 or 7, characterized in that the outlet section (16) tapers more sharply along the longitudinal axis (A) than the inlet section (12) widens along the longitudinal axis (A).

9. Pressure loading system (1) according to one of the preceding claims, characterized in that the gas supply (44) opens into the cavity (26) through the inlet opening (28) in the inlet section (12) and that the gas supply (44) has a gas guide element (34) arranged at least partially in the particle inlet (10).

10. Pressure loading system (1) according to claim 9, characterized in that the gas guide element (34) has at least two gas guide vanes (36) arranged axially symmetrically about the longitudinal axis (A).

11. Pressure loading system (1) according to one of the preceding claims, characterized in that the particle inlet (10) is designed as a nozzle coaxial with the longitudinal axis (A).

12. Pressure loading system (1) according to claim 10 and 11, characterized in that the gas guide vanes (36) extend in the radial direction (R) from the longitudinal axis (A) to an inner surface of the particle inlet (10), wherein they form a vane outer edge (38) along the inner surface of the particle inlet (10) which is inclined at least in sections with respect to the direction of the longitudinal axis (A).

13. Pressure loading system (1) according to claim 12, characterized in that the blade outer edge (38) forms a curved curve with an angle of inclination increasing in the direction from the inlet opening (28) to the outlet opening (30) with respect to the direction of the longitudinal axis (A).

14. Pressure loading system (1) according to claim 13, characterized in that the angle of inclination (a max) the blade outer edge (38) at its outlet-side end (40) in the axial direction is > 30°, preferably > 40°, particularly preferably > 45° relative to the direction of the longitudinal axis (A).

15. Pressure loading system (1) according to one of the preceding claims, characterized in that by means of the rotating gas flow over an area proportion of at least 80%, preferably at least 85%, particularly preferably at least 90% of the inner surface (24) and at a distance of 1 mm from the inner surface (24) a shear stress of at least 1 Pa, preferably at least 5 Pa, particularly preferably at least 10 Pa can be generated.

16. Pressure loading system (1) according to one of the preceding claims, characterized by a gas pressure source connectable to the gas supply (44) which is designed to provide a gas flow under an inlet pressure P of 3 to 12 bar, preferably 6 to 10 bar.

17. Pressure loading system (1) according to one of the preceding claims, characterized in that the gas pressure source is arranged to provide a gas flow with a mass flow S of 20 to 100 kg / s.

18. Pressure loading system (1) according to one of the preceding claims, characterized in that the gas pressure source is arranged to provide the gas flow for at least 0.5 seconds, preferably at least 1 second.

19. Pressure loading system (1) according to one of claims 16 to 18, characterized in that the gas pressure source comprises a gas pressure accumulator.

20. A method for cleaning a pressure loading tank (20) having a longitudinal axis (A), a pressure vessel wall (22) with an inner surface (24) circumscribing a cavity (26), and having an inlet section (12), a center section (14), and an outlet section (16) along the longitudinal axis (A), comprising introducing a gas stream (2) into the cavity (26) in the inlet section (12), wherein the gas stream (2) in the cavity (26) is set into rotation about the longitudinal axis (A).

21. Method according to claim 20, characterized in that by means of the rotating gas flow over an area proportion of at least 80%, preferably at least 85%, particularly preferably at least 90% of the inner surface (24) and at a distance of 1 mm from the inner surface (24) a shear stress of at least 1 Pa, preferably at least 5 Pa, particularly preferably at least 10 Pa is generated.

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