Deagglomeration device and particle measuring device

Abstract

The invention relates to a deagglomeration device (1) for individualizing particles and dissolving particle agglomerations in a carrier gas particle mixture (2), designed for use in a particle measuring device comprising a through-flow body (3), which delimits a through-flow chamber (4), for the carrier gas particle mixture (2), wherein the through-flow body (3) has a curved chamber wall (5) in order to generate a circular flow and / or a turbulent flow of the carrier gas particle mixture (3) when flowing over the chamber wall (5), the chamber wall (5) is equipped with an inlet opening (6) for a carrier gas particle mixture (2) and an outlet opening (7) for the carrier gas particle mixture (2), and the rest of the through-flow body (3) is closed and / or can be closed relative to the surroundings. A carrier gas particle mixture (2) can be supplied to the through-flow chamber (4) via the inlet opening (6), and the carrier gas particle mixture (2) can be transported from the inlet opening (6) to the outlet opening (7), thereby forming a circular flow along the chamber wall (5) of the through-flow body (2), and can be discharged out of the through-flow chamber (4) via the outlet opening (7).

Description

[0001] Deagglomeration device and particle measuring device

[0002] The invention relates to a deagglomeration device for particle separation and dissolution of particle agglomerations in a carrier gas-particle mixture.

[0003] Furthermore, the present invention relates to a particle measuring device, in particular for particle classification and / or for determining grain size and grain shape information, with at least one deagglomeration device of the aforementioned type or with several deagglomeration devices of the aforementioned type connected in series or in parallel in a flow path.

[0004] In many applications, particle size and shape information are important process and quality indicators. Dry powders composed of small particles are used and manufactured in numerous different industries. Examples of such powders include food, pharmaceuticals, cement, abrasives, pigments, toners, and surface coating materials. It is often very important to measure and control the size of these dry powders, as the size can influence the function of a material. One example is the size of pharmaceutical powders, which affects the rate at which the active ingredients are dissolved and absorbed into the body.

[0005] Numerous methods are available for determining particle size, including laser diffraction, image analysis, and time-of-flight, among others. When measuring the size of dry powders using these methods, problems are often encountered with the agglomeration of individual particles into clusters of particles, resulting in an inaccurate particle size measurement. This particle agglomeration and various methods for de-agglomerating or dissolving these clusters are known in the art.

[0006] Dynamic image analysis makes it possible to analyze grain size and shape information in detail and representatively. For this purpose, a sample stream is generated, which is then captured and analyzed by a camera system. Particle size, shape, and number can be determined from the images of the sample stream obtained with a camera system. Dynamic image analysis is used to determine grain size and shape information, primarily for larger particles. The particles are in motion during the recording. In most cases, dynamic image analysis illuminates the particle stream from one side by a light source, and the particle images are recorded as shadow projectors. The particles can move in an air stream, which is intended to separate the particles in agglomerated powders.Short exposure times and high acquisition rates are required to achieve sufficient particle detection during measurements and prevent motion blur. A particle measurement using dynamic image analysis typically takes one to five minutes and, depending on the sample, typically detects from a few tens of thousands to many millions of particles.

[0007] To determine particle size distributions, especially of smaller particles, other analytical methods can be used, such as laser diffraction analysis, also known as static light scattering. This method is based on the deflection of a laser beam by a collective of particles, which may be dispersed in an air stream. The diffraction or scattering angles are characteristic of the particle size. Representative particle size measurements depend, among other things, on the particle concentration in the sample.

[0008] When determining particle size and shape information, it is important to provide separated particles in a sample volume to determine the actual size and / or number of particles. If particle agglomerations occur, the detected particle size may be several times the actual particle size, since the outer diameter of the particle agglomerate is measured.

[0009] Particle agglomeration can become particularly important when interactions between particles become more significant with decreasing particle size, which is especially the case for particles in the micrometer range or smaller. Van der Waals interactions increase with decreasing particle size and can be 100 times greater than the influence of gravity for particles 10 pm in size. Other influencing factors can also lead to increased agglomeration of certain particles. For example, the water content in the particle powder can affect particle agglomeration.

[0010] As described above, dynamic image analysis methods attempt to separate agglomerated powders by moving the particles in an air stream. However, depending on the sample material, particle agglomerations can still occur for particles in the size range smaller than 1 pm, resulting in difficulties in representatively measuring particle size, shape, and / or number.

[0011] The object of the present invention is to remedy this situation and to provide a deagglomeration device for particle separation and dissolution of particle agglomerations in a carrier gas-particle mixture for use in a particle measuring device, wherein the deagglomeration device leads to effective deagglomeration in agglomerated powders and thus simplifies and ensures the detailed and representative analysis of a sample material for determining grain number, grain size and grain shape information.

[0012] To achieve the aforementioned object, the invention proposes a deagglomeration device for particle separation and dissolution of particle agglomerations in a carrier gas-particle mixture having the features of patent claim 1 and a particle measuring device, in particular designed for dynamic image analysis, laser diffraction analysis, or time-of-flight analysis, with at least one deagglomeration device of the type according to the invention or with several deagglomeration devices of the type according to the invention connected in series or in parallel in a flow path according to claim 14. Advantageous developments of the invention are the subject of the dependent claims.

[0013] The deagglomeration device according to the invention comprises a flow-through body or housing for the carrier gas-particle mixture, which defines a flow-through chamber and in which highly effective deagglomeration of agglomerated powders occurs during the flow. The flow-through body has a curved chamber wall for generating a circular flow or vortex flow of the carrier gas-particle mixture as it flows over the chamber wall. Preferably, only one inlet opening for a carrier gas-particle mixture and preferably only one outlet opening for the carrier gas-particle mixture are provided in the chamber wall. The inlet and outlet of the carrier gas-particle mixture then preferably occur only via the inlet and outlet openings.

[0014] The flow-through body is also closed and / or closable from the environment. The flow-through body is designed to be closed and forms a closed system. A "closed system" within the meaning of the invention is, in particular, a design of the flow-through body in which the flow-through body is particle-tight, in particular gas-tight, to create pressure differences between the inlet and outlet openings.

[0015] According to the invention, a carrier gas-particle mixture can be fed to the flow-through body via the inlet opening in the chamber wall, wherein the carrier gas-particle mixture can be transported or flows from the inlet opening to the outlet opening, forming a circular flow or vortex flow along the inner surface of the chamber wall, and wherein the carrier gas-particle mixture can be discharged from the flow-through chamber via the outlet opening for subsequent particle size, particle shape and particle number analysis in a particle measuring device.

[0016] As the carrier gas-particle mixture flows through the flow-through chamber and along the curved chamber wall of the flow-through body, particle-wall and particle-particle collisions are generated due to the structurally enforced circular flow and / or vortex flow, combined with high shear forces caused by changes in the direction of the air velocity. Different accelerations of the gas phase and the particles it contains as they flow through the flow-through body lead to further dispersal and dissolution of particle agglomerations. A region of high shear forces forms in the area of ​​the chamber wall, which leads to the dispersal and dissolution of particle clusters. Impacts or blows against the wall and particle-to-particle collisions that are sufficiently high or strong serve to disperse clusters and disintegrate them, but should be low enough to avoid "grinding" the particles.The disintegration and breakup of individual particles into even smaller particles can be avoided by a suitable flow velocity and by a suitable guidance of the carrier gas-particle mixture along the curved chamber wall.

[0017] The particles are trapped in the flow-through body, which forms a retention body, by means of a circular flow and / or vortex flow created when flowing over the chamber wall. According to the invention, this can result in a retention factor of the particles in the flow-through body that is 10 times or more higher than with pure pipe or hose flow. During the retention phase, the particles are forced against the inner wall of the flow-through body by centrifugal forces and separated from one another by interactions with the chamber wall. Factors influencing the degree of deagglomeration include the surface roughness of the chamber wall and the flow velocity or volume flow of the carrier gas-particle mixture.

[0018] Tests conducted within the scope of the invention have confirmed the high effectiveness of the deagglomeration device according to the invention. Tests on particle separation and dissolution of particle agglomerations of carrier gas-particle mixtures with particles in the size range of less than 1 to 10 pm have confirmed that the deagglomeration device according to the invention can lead to highly efficient particle separation and particle agglomeration, particularly with smaller particle sizes.

[0019] Comparative tests in which the carrier gas-particle mixture was conveyed from a conveying device via a pipe or hose directly to the particle measuring device or into a sample chamber of the particle measuring device showed that without using the deagglomeration device according to the invention, at the same flow velocity and composition of a carrier gas-particle mixture, significantly higher particle agglomerations down to the millimeter size range occurred.

[0020] For particle analysis, it is desirable to make a sample available for measurement as completely as possible and to avoid contamination of the laboratory equipment by sample powder. For this purpose, the deagglomeration device according to the invention provides for the design of the flow-through body as a substantially closed system, wherein the flow-through body preferably only allows the carrier gas-particle mixture to be supplied via the inlet opening and the carrier gas-particle mixture to be removed via the outlet opening, and at least substantially prevents any undesired transfer of particles from the flow-through body into the environment.

[0021] Furthermore, due to its shape and the geometry of the chamber wall, the flow-through body is designed such that only low flow resistance occurs when the carrier gas-particle mixture flows through the flow-through body. In particular, the flow-through body is free of internal components and / or there are preferably no projections on the inner wall that extend inwards by more than 5 mm, preferably more than 2 mm, more preferably more than 1 mm, particularly preferably more than 0.5 mm or less, relative to adjacent wall surfaces of the chamber wall. Particularly preferably, the chamber wall of the flow-through body encloses or surrounds a rotational volume that is preferably closed off from the environment with the exception of the inlet opening and the outlet opening in the chamber wall.This does not preclude the possibility of part of the chamber wall being opened by a detachable wall section to allow access to the rotating body, for example for cleaning purposes.

[0022] Further preferably, a flow volume of the flow-through body, which is delimited by the chamber wall of the flow-through body, corresponds to the rotational volume of the flow-through body, wherein the inner surface of the flow-through body is formed by rotating a generating curve around a rotational axis and the flow volume is delimited by the generating curve. The flow volume ends at the inner side of the chamber wall of the flow-through body and does not extend beyond the inlet opening and the outlet opening of the flow-through body. The flow volume of the flow-through body preferably has a size that corresponds to the size of the rotational volume delimited by the chamber wall of the flow-through body, wherein according to the invention the maximum rotational volume is used for particle flow.

[0023] Typical entry and exit velocities of the carrier gas-particle mixture into and out of the flow body can be in the order of magnitude between 1 and 100 m / s.

[0024] In a particularly preferred embodiment of the invention, the carrier gas-particle mixture is introduced into the flow chamber via the inlet opening tangentially adjacent to the chamber wall. Accordingly, the inlet opening can be connected tangentially to an inner diameter of the chamber wall.

[0025] A “tangential” inlet of the carrier gas-particle mixture is understood to mean in particular that there is no sudden change in the flow direction of the carrier gas-particle mixture entering the flow chamber when passing through the inlet opening.

[0026] A “tangential” inlet is further understood to mean, in particular, that when the carrier gas-particle mixture enters the flow-through chamber, no or only a slight directional deflection of the carrier gas flow occurs in the transition area between the inlet opening and the chamber wall of the flow-through body.

[0027] Preferably, the carrier gas-particle mixture is introduced tangentially into a circular or vortex flow formed on the chamber wall.

[0028] Additionally or alternatively, the invention may provide for the carrier gas-particle mixture to be discharged from the flow chamber via the outlet opening tangentially adjacent to the chamber wall. Accordingly, the outlet opening may also be connected tangentially to an inner diameter of the chamber wall.

[0029] A "tangential" outflow of the carrier gas-particle mixture is understood to mean, in particular, that there is no sudden change in the flow direction of the carrier gas-particle mixture emerging from the flow chamber when passing through the outlet opening.

[0030] A "tangential" outlet is further understood to mean in particular that when the carrier gas-particle mixture leaves the flow-through chamber, there is no or only a slight redirection of the carrier gas flow in the transition area between the outlet opening and the chamber wall of the flow-through body.

[0031] A "tangential" inlet or outlet is to be understood in particular as meaning that the carrier gas-particle mixture is fed tangentially to the inner surface of the chamber wall of the flow chamber or impinges on the inner surface.

[0032] A high degree of deagglomeration with low flow losses is achieved by a tangential inlet or a tangential inflow of the carrier gas-particle mixture into the flow body and / or a tangential outlet or a tangential outflow of the carrier gas-particle mixture from the flow body.

[0033] To generate a circular flow and / or vortex flow, the chamber wall can be concavely curved at least in sections. In particular, the chamber wall is circular in cross-section at least in sections, preferably over the entire height of the flow-through body. The flow-through body is preferably designed as a hollow rotating body, in particular as a hollow cylinder. The flow-through body is particularly preferably designed as a closed hollow rotating body.

[0034] The chamber wall of the flow body can form and / or delimit a cylindrical flow chamber.

[0035] The chamber wall can be designed as a hollow cylinder with an inner cylindrical surface along which the carrier gas-particle mixture flows in the circumferential direction after entering the flow body and is brought onto a circular path.

[0036] In order to close off the flow-through chamber, which is laterally or radially delimited by the chamber wall, upwards and / or downwards or in the axial direction and, preferably, to form a system that is essentially closed to the environment, the flow-through body can have an upper, preferably flat, end wall and / or a lower, preferably flat, end wall, which adjoin the chamber wall perpendicular to the longitudinal axis of the flow-through chamber and whose inner surfaces delimit the flow-through chamber in the axial direction.

[0037] Alternatively, it is possible for the flow-through body to form and / or delimit a flow-through chamber having, in the use state of the deagglomeration device according to the invention, a preferably upper cylindrical inlet section and, in the use state, a lower conical or truncated cone-shaped outlet section, and having a corresponding inner wall geometry. The cylindrical inlet section is delimited by a first axial wall section of the chamber wall of the flow-through body, which forms an inner cylindrical surface along which the carrier gas-particle mixture flows in the circumferential direction after entering the flow-through body and is guided onto a circular path. The inlet opening is provided in the first axial wall section of the flow-through body. The carrier gas-particle mixture is supplied via the inlet opening in the inlet cylinder section, in particular tangentially.

[0038] The carrier gas-particle mixture is discharged via an outlet opening in the outlet section, particularly axially, preferably centrally to the rotation axis. The conical or truncated cone-shaped outlet section is defined by a further axial wall section of the chamber wall of the flow body. This further axial wall section can taper downwards and have or form the outlet opening at its lower end.

[0039] The flow-through body can have an upper, preferably flat, radial wall section which adjoins the first axial wall section of the chamber wall perpendicular to the longitudinal axis of the flow-through chamber and delimits the flow-through chamber upwards in the axial direction.

[0040] Further preferably, the chamber wall of the flow-through body, in particular in the region of the inlet opening and / or in the region of the outlet opening, is aligned on the inside and free of projections directed radially inwards in order to avoid an accumulation and build-up of particles that are difficult to remove.

[0041] Alternatively, it is also possible for the flow-through body to have and / or define a truncated cone-shaped flow chamber, wherein the inlet of the carrier gas-particle mixture preferably occurs tangentially via an inlet opening in an inner wall of the flow-through body, which can be provided adjacent to an upper conical edge in the use state, at which the cone reaches its largest radius. The outlet can occur tangentially or, preferably, axially via an outlet opening, wherein the outlet opening can be provided at the lower conical edge, at which the cone reaches its largest radius.

[0042] Particularly preferably, an embodiment of the flow-through body is provided in which the flow-through body is free of internal components and / or free of mechanically and / or motor-driven and / or movable components and / or wherein the flow volume of the flow-through body corresponds to the rotation volume of the flow-through body.

[0043] Preferably, no fittings are provided in the flow chamber that could narrow the flow-through area of ​​the flow chamber and cause particle accumulation and build-up.

[0044] Further preferably, the flow-through body is free of mechanically moved and / or movable parts and / or internal components that can restrict or reduce the flow volume, wherein the flow volume of the flow-through body can at least substantially correspond to the rotation volume relative to the inner surface of the flow-through body.

[0045] However, internals can also be provided, provided it is ensured that they cause little to no particle deposits. The flow around the internals must be optimized to avoid dead zones. In any case, a low flow resistance should be ensured when passing the carrier gas-particle mixture through the flow chamber.

[0046] The inlet opening can be connected to an inlet line for supplying the carrier gas-particle mixture into the flow chamber. Furthermore, an outlet line can be provided for discharging the carrier gas-particle mixture, which outlet line is connected to the outlet opening and originates at the outlet opening. The inlet line can be connected and / or connectable to a sample introduction device and / or terminate in the region of the sample introduction device. The outlet line can be connected and / or connectable to a particle measuring device, in particular a particle measuring volume, or terminate in the region of the particle measuring device.

[0047] In the simplest case, the inlet and / or outlet lines can be hoses. However, rigid routing via a pipe is also possible.

[0048] The inlet line can, for example, be connected to a vibrating trough and / or terminate in the vicinity of a vibrating trough, with the sample being introduced via the vibrating trough. A particle sample introduced into the vibrating trough can be drawn in via the inlet line, along with ambient air as a carrier gas, and transported to the flow chamber.

[0049] The outlet line can be connected and / or connectable to an extraction device for extracting the carrier gas-particle mixture through the flow chamber. Alternatively or additionally, the inlet line can be connected and / or connectable to a conveying device for transporting the carrier gas-particle mixture through the flow chamber to the particle measuring device.

[0050] Preferably, at least one connection region, in particular designed as a pipe socket, can be provided on the flow-through body for connection to a hose or a pipe in order to introduce the carrier gas-particle mixture into the flow-through chamber via the inlet opening or to discharge the carrier gas-particle mixture from the flow-through chamber via the outlet opening. The connection region can be formed on the flow-through body in particular tangentially, furthermore in particular radially outwardly. For a tangential supply of the carrier gas-particle mixture into the flow-through chamber, the connection region can intersect the chamber wall of the flow-through body tangentially, i.e. laterally and not radially. The inlet opening in the chamber wall of the flow-through body can accordingly have a non-circular, in particular drop-shaped, boundary contour.

[0051] A connection area, particularly designed as a pipe socket, can be provided for discharging the carrier gas-particle mixture from the flow-through chamber. In a cylindrical flow-through chamber, the connection area can be formed or formed onto the flow-through body, particularly tangentially, and more particularly radially outwardly. For tangential discharge of the carrier gas-particle mixture from the flow-through chamber, the connection area can intersect the chamber wall tangentially, i.e., laterally and not radially. Accordingly, the outlet opening in the chamber wall of the flow-through body can also have a non-circular, particularly drop-shaped, boundary contour.

[0052] If the flow-through body forms or delimits a flow-through chamber with an upper cylindrical inlet section and a lower conical (truncated) outlet section, based on the state of use, a connection area can be formed or formed on a chamber wall of the flow-through body forming the outlet section, in particular centrally to the axis of rotation of the outlet section at the lower end of the truncated cone, wherein the carrier gas-particle mixture is discharged downwards in the axial direction.

[0053] In order to create impacts between the particles and the chamber wall of the flow-through body when the carrier gas-particle mixture flows over the chamber wall, so that clusters of particles are more easily distributed and dissolved, and in order to avoid "grinding" of the particles and further particle size reduction, the chamber wall can be embossed and / or surface-treated in a certain way. Surface effects can help to keep the particles in the area of ​​the surface or inner surface of the chamber wall of the flow-through body and to rub them against each other for longer, which intensifies the dissolution of particle agglomerations. Patterns can be embossed into the inside of the chamber wall. For example, a profiling or embossing can be achieved with a profile orEmbossing height of less than 5 mm, preferably less than 2 mm, more preferably less than 1 mm, particularly preferably less than 0.5 mm.

[0054] The chamber wall can also be roughened on the inside, for example by sandblasting, which can have a positive effect on the degree of deagglomeration.

[0055] A maximum roughness depth of the chamber wall according to DIN EN ISO 25178 can be between 100 and 1000 pm, preferably between 200 and 500 pm.

[0056] However, the flow-through body particularly preferably has a smooth inner surface which can preferably have a roughness depth of less than 500 pm, more preferably of less than 200 pm, particularly preferably of 100 pm.

[0057] The chamber wall of the flow body can be closed with the exception of the inlet opening and the outlet opening.

[0058] However, the chamber wall can also have a wall section that is detachably connected to the chamber wall in order to release an opening in the chamber wall after the wall section has been detached, through which, for example, the interior of the flow-through body can be cleaned.

[0059] For example, the flow-through body can have at least one further opening to enable easy cleaning of the flow-through body or the flow-through chamber, if required. To prevent particles from escaping via the further opening, a cover can be provided to close the further opening. The cover can be connected to the flow-through body in a form-fitting and / or force-fitting manner, for example via a screw connection or a bayonet connection, to achieve easy cleaning of the flow-through chamber. The cover can in particular be sealed off from the flow-through body via at least one sealing means, so that the flow-through body, with the exception of the inlet opening and the outlet opening, forms an essentially closed system when the cover is closed. The flow-through body can be designed in one or more parts.The flow chamber can be formed by several chamber walls that, when the chamber walls are connected to each other, seal the flow chamber off from the environment, so that, with the exception of at least one inlet opening and at least one outlet opening for particle-containing carrier gas, no particle-carrier gas exchange with the environment is possible. Several chamber walls or a lid, as described above for closing an opening in a chamber wall, can be connected to each other in a form-fitting and / or force-fitting manner, for example, via a screw connection or a bayonet connection.

[0060] Furthermore, automatic cleaning of the flow-through body can be provided, for example, after a certain period of time has elapsed for the carrier gas-particle mixture to flow through the flow-through body and / or upon reaching a certain flow resistance. To achieve automatic cleaning, a correspondingly designed measuring, control, and / or regulating device can be provided.

[0061] For cleaning the flow-through body, it can be connected to a suction device for extracting a cleaning fluid, for example, air, through or out of the flow-through chamber, or to a conveying device for transporting a cleaning fluid, for example, compressed air, through the flow-through chamber. Furthermore, at least one fluid reservoir for a cleaning fluid can be provided, for example, a compressed air reservoir.

[0062] Furthermore, the connection of a hose to the flow-through body via the connection area of ​​the flow-through body for the supply of the carrier gas-particle mixture via the inlet opening into the flow-through chamber and / or for the discharge of the carrier gas-particle mixture via the outlet opening from the flow-through chamber enables easy replacement of the lines provided for the introduction or discharge, in particular hoses, which further reduces the cleaning effort.

[0063] The invention is explained below by way of example with reference to the drawing and preferred embodiments of the invention. The invention is not limited to the embodiments shown. The drawing shows: Fig. 1 shows a first embodiment of a deagglomeration device according to the invention for particle separation and dissolution of deagglomerations in a carrier gas-particle mixture in a perspective side view.

[0064] Fig. 2 is a plan view of the deagglomeration device from Fig. 1,

[0065] Fig. 3 is a side view of the deagglomeration device of Fig. 1,

[0066] Fig. 4 is a perspective partial sectional view of the deagglomeration device of Fig. 1 along the section line IV - IV of Fig. 2,

[0067] Fig. 5 is a perspective partial sectional view of the deagglomeration device of Fig. 1 along the section line V - V of Fig. 2,

[0068] Fig. 6 is a cross-sectional view of the deagglomeration device of Fig. 1 along the section line VI - VI of Fig. 3,

[0069] Fig. 7 is a cross-sectional view of the deagglomeration device of Fig. 1 along the section line VII - VII of Fig. 3,

[0070] Fig. 8 shows a further embodiment of a deagglomeration device according to the invention in a perspective side view,

[0071] Fig. 9 is a plan view of the deagglomeration device from Fig. 8,

[0072] Fig. 10 is a side view of the deagglomeration device of Fig. 8,

[0073] Fig. 11 is a cross-sectional view of the deagglomeration device along the section line XI - XI of Fig. 10,

[0074] Fig. 12 is a cross-sectional view of the deagglomeration device of Fig. 8 along the section line XII - XII of Fig. 10,

[0075] Fig. 13 is a cross-sectional view of a third embodiment of a deagglomeration device according to the invention with radial supply of a carrier gas-particle mixture, Fig. 14 is the result of the particle analysis when examining cement-containing carrier gas using a deagglomeration device according to the invention integrated into the flow path between a sample application device and a particle measuring device,

[0076] Fig. 15 shows the result of the particle analysis according to the state of the art in the investigation of cement-containing carrier gas using a hose connection integrated into the flow path between a sample application device and a particle measuring device and

[0077] Fig. 16 is a perspective view of a further embodiment of a deagglomeration device according to the invention for particle separation and dissolution of deagglomerations in a carrier gas-particle mixture, wherein the deagglomeration device has a flow-through body with an hourglass geometry,

[0078] Figures 1 to 7 and 8 to 12 show alternative embodiments of a deagglomeration device 1 according to the invention for particle separation and dissolution of particle agglomerations in a carrier gas-particle mixture 2. The carrier gas-particle mixture 2 is, for example, a dispersion of particles in an air stream.

[0079] Fig. 13 shows a third alternative embodiment of a deagglomeration device 1 with radial supply of a carrier gas-particle mixture 2 into a flow chamber 4 of the deagglomeration device 1.

[0080] The deagglomeration device 1 has a flow-through body 3 that defines a flow-through chamber 4. The flow-through body 3 has a curved chamber wall 5.

[0081] As can be seen particularly from the figures, only one inlet opening 6 and one outlet opening 7 for the carrier gas-particle mixture 2 are provided in the chamber wall 5. Otherwise, the flow-through body 3 is designed as a closed system. Gas and / or particle transfer into or out of the flow-through chamber 4 preferably occurs only via the inlet opening 6 and the outlet opening 7. Not shown is the fact that the flow-through body 3 may have a further opening that can be closed with a lid to allow access to the flow-through chamber 4 from the outside, for example, for cleaning purposes.

[0082] A carrier gas-particle mixture 2, in particular particle-containing air, can be fed into the flow-through chamber 4 via the inlet opening 6. After entering via the inlet opening 6, the carrier gas-particle mixture 2 is then transported to the outlet opening 7 due to pressure differences along the inwardly curved chamber wall 5, forming a circular flow or vortex flow, shown schematically in Figures 6, 7 and 12, and then exits the flow-through chamber 4 via the outlet opening 7.

[0083] The formation of a circular flow or vortex flow of the carrier gas-particle mixture 2 as it flows through the flow chamber 4 results in impacts or collisions between the particles against the chamber wall 5 and each other, leading to the distribution and dissolution of particle agglomerations. Furthermore, the closed design of the flow body 3 ensures that no unwanted particles escape into the environment as they flow through the flow chamber 4.

[0084] In a particularly preferred embodiment, the carrier gas-particle mixture 2 is supplied to the flow-through chamber 4 via the inlet opening 6 tangentially adjacent to the chamber wall 5 and, in the embodiment according to Figures 1 to 7, is also discharged from the flow-through chamber 4 via the outlet opening 7 tangentially adjacent to the chamber wall 5. Accordingly, the inlet opening 6 and the outlet opening 7 can each connect tangentially to an inner diameter of the chamber wall 5 of the flow-through body 3.

[0085] The tangential inlet and outlet of the carrier gas-particle mixture into and out of the flow-through chamber 4 leads to an increase in the degree of deagglomeration and is further advantageous for preventing undesired retention or deposits of particles in the region of the inlet opening 6 and / or the outlet opening 7. These deposits can lead to a reduction in the degree of deagglomeration and make cleaning of the deagglomeration device 1 necessary. The flow direction of the carrier gas-particle mixture 2 preferably does not change or changes only slightly at the inlet opening 6 and at the outlet opening 7 at the transition of the flow path to the chamber wall 5. The carrier gas-particle mixture 2 is thus fed in the flow direction of a circular or vortex flow formed when the carrier gas-particle mixture 2 is passed through the flow-through body 3.

[0086] Compared to a radial supply line, the inlet opening 6 has a non-circular, particularly drop-shaped, boundary contour when the carrier gas-particle mixture 2 is supplied tangentially. The same applies to the outlet opening 7. As can be seen from a comparison of Figs. 12 and 13, an inlet arc length 8 is larger when the carrier gas-particle mixture 2 is supplied tangentially (Fig. 12) than an inlet arc length 9 when the carrier gas-particle mixture 2 is supplied radially (Fig. 13).

[0087] In the alternative embodiments shown in Figures 8 to 12, the carrier gas-particle mixture 2 is discharged from the flow-through chamber 4 in a vertical or gravity direction, preferably axially to a central longitudinal axis Y of the flow-through body 3 or the flow-through chamber 4, in contrast to the embodiment shown in Figures 1 to 7. In the alternative embodiments shown in Figures 8 to 12, an axial connection of the outlet opening 7 to the flow-through chamber 4 is accordingly provided. In this embodiment, the carrier gas-particle mixture 2 is sucked in or blown in tangentially and brought onto a circular path. By tapering the adjacent cone, the rotational speed decreases, so that particles are thrown against the cone walls by centrifugal forces and thus decelerated, which leads to deagglomeration.

[0088] According to the embodiment shown in Figures 1 to 7, the flow-through body 3 defines a cylindrical flow-through chamber 4. The chamber wall 5 of the flow-through body 3 is preferably formed in one piece and can be made of a polymeric material.

[0089] The flow body can be made of polymeric materials or of metal, for example stainless steel.

[0090] The chamber wall 5 has a first axial wall section 10 formed as a hollow cylinder, as well as an upper first flat radial wall section 11 and a lower second flat radial wall section 12. The inner surface of the first wall section 10 forms an inner circumferential surface 13 and delimits the cylindrical flow chamber 4 in the radial direction. The flat radial wall sections 11, 12 form inner base surfaces 14, 15 and delimit the flow chamber 4 in the axial direction upwards and downwards.

[0091] The inlet opening 6 and the outlet opening 7 are formed in the first wall section 10, which is designed as a hollow cylinder. The first wall section 10 has two integrally formed connection areas 16, 17 designed as pipe sockets for connection to a hose line or a pipe. The connection areas 16, 17 adjoin tangentially to the inner diameter of the chamber wall 5. The carrier gas-particle mixture 2 is supplied to and discharged from the flow-through chamber 4 via hoses or pipes (not shown) and the connection areas 16, 17.

[0092] According to the embodiment shown in Figures 8 to 12, the flow-through body 3 defines a flow-through chamber 4, which has an upper inlet cylinder section 18 and a lower conical section 19. The chamber wall 5 of the flow-through body 3 is again preferably formed in one piece and can be made of a polymeric material.

[0093] The chamber wall 5 has a first axial wall section 20 designed as a hollow cylinder and a second axial wall section designed as a hollow cone

[0094] 21. In addition, an upper flat wall section 22 is provided. The inner surface of the first wall section 20 forms a shell surface 23 and delimits the inlet cylinder section 18 of the flow chamber 4. The inner surface of the second wall section 21 forms a conical shell surface 24 and delimits the lower conical section 19 of the flow chamber 4. The flat wall section

[0095] 22 forms a base area 25 and limits the flow chamber 4 upwards in the axial direction.

[0096] The inlet opening 6 is formed in the first wall section 20, which is designed as a hollow cylinder.

[0097] The first wall section 20, designed as a hollow cylinder, has a molded-on connection area 26 designed as a pipe socket for connection to a hose line or a pipe. The connection area 26 opens tangentially into the flow-through chamber 4 at the inlet opening 6. The second wall section 21, designed as a hollow cone, merges at its lower end into a molded-on connection area 27 designed as a pipe socket for connection to a hose line or a pipe. The carrier gas-particle mixture 2 is fed into and discharged from the flow-through chamber 4 via hoses or pipes and the connection areas 26, 27. According to the embodiment shown in Figures 8 to 12, a tangential feed and an axial discharge of the carrier gas-particle mixture 2 is provided centrally to the central axis Y of the flow-through chamber 4.

[0098] It is not shown that the supply connection areas 16, 26 are connected and / or connectable to a sample introduction device via a hose or a pipe. The hose or pipe can end in the area of ​​the sample introduction device. The discharge connection areas 17, 27 can be connected and / or connectable to a particle measuring device, in particular a particle measuring volume, via a hose or a pipe. This depicts the flow path from the sample introduction device to the particle measuring device. It is understood that additional components, functional units, and lines can be integrated into the flow path from the sample introduction device to the particle measuring device.

[0099] Particularly preferably, the discharge connection region 17, 27 can be connected and / or connectable to a suction device downstream of the deagglomeration device 1 for suctioning the carrier gas-particle mixture through the flow chamber 4. Alternatively, it is possible to provide a conveying device for conveying the carrier gas-particle mixture 2, which is integrated into the flow path upstream of the flow chamber 4 in the flow direction, preferably downstream of a sample introduction device in the flow direction. For example, the supply connection region 16, 26 can be fluidically connected to a vibrating trough, making it possible to suck in a particle sample together with ambient air as the carrier gas in the region of the vibrating trough and subsequently transport it into the flow chamber 4. The vibrating trough is then part of the sample introduction device.

[0100] Furthermore, the chamber wall 5, particularly in the region of the axial wall sections 10, 20, 21 designed as hollow cylinders or hollow cones, can have an embossing or be roughened on the inside, for example by sandblasting the surface. By embossing and / or roughening the surface on the inside of the chamber wall 5, higher shear forces can be generated in order to increase the degree of deagglomeration. The embossing height can preferably be less than 5 mm, more preferably less than 2 mm, more preferably less than 1 mm. The maximum roughness depth of the chamber wall 5 on its inside can be between 100 and 1000 pm, preferably less than 200 pm, according to DIN EN ISO 25178.

[0101] As can be seen from the figures, the flow body 4 is free of internals, and the chamber wall 5 is free of projections on its inner side. This prevents the formation of particle deposits on projections and internals. In principle, however, such projections and / or internals can also be provided to increase shear forces.

[0102] Figure 14 shows the results of particle analysis by laser diffraction using a Sync analyzer from Microtrac (DE) as the particle measuring device. Cement-containing air was measured as the carrier gas-particle mixture 2. The measurement was performed by evaluating the images obtained by image capture; for this purpose, the number and a relative particle size (uncalibrated) are output by the particle measuring device using an algorithm. The dispersion pressure was 20 PSI. The average gas velocity was 35 m / s, which corresponds to a gas flow of 180 L / min. A deagglomeration device 1 of the type shown in Figs. 1-7 was integrated into the flow path between a vibrating chute as the sample introduction device, through which the carrier gas-particle mixture was drawn in, and the particle measuring device.

[0103] The deagglomeration device 1 according to the invention has no or only a very small dead volume. In the flow chamber 4, there is no significant change of direction (gas phase and particle phase) upon entry into the flow chamber 4 due to a corresponding arrangement of the inlet opening 6 and the outlet opening 7. Due to the formation of the circular or vortex flow, the particles are held for varying lengths of time in the buffer volume formed by the flow chamber 4 and distributed over the measurement time.

[0104] Figure 15 shows the result of the particle analysis using the same measurement setup and the same carrier gas-particle mixture, with the flow line from the vibrating trough as the sample introduction device to the particle measuring device being established solely via a hose line. A deagglomeration device 1 was not used. A qualitative comparison of Figures 14 and 15 clearly shows that the particles detected during image acquisition according to Figure 14 are distributed across a larger number of measurement images using the deagglomeration device 1 according to the invention. This demonstrates that a greater resolution of particle agglomerations can be achieved by using the deagglomeration device 1 according to the invention.

[0105] Fig. 16 shows a further embodiment of a deagglomeration device 1 which has a flow-through body 3 whose inner surface is formed by rotation of a generating curve around a rotation axis and which has the geometry of an hourglass.

[0106] List of reference symbols:

[0107] 1 deagglomeration device 15 floor area

[0108] 2 Carrier gas-particle mixture 16 Connection area 3 Flow body 17 Connection area

[0109] 4 Flow chamber 20 18 Inlet cylinder section

[0110] 5 Chamber wall 19 Cone section

[0111] 6 Inlet opening 20 Wall section

[0112] 7 Outlet opening 21 Wall section 8 Inlet bend length 22 Wall section

[0113] 9 Inlet bend length 25 23 Shell surface

[0114] 10 Wall section 24 Shell surface

[0115] 11 wall section 25 floor area

[0116] 12 Wall section 26 Connection area 13 Shell surface 27 Connection area

[0117] 14 floor space

Claims

Patent claims:

1. Deagglomeration device (1) for particle separation and dissolution of particle agglomerations in a carrier gas-particle mixture (2), designed for use in a particle measuring device, with a flow-through body (3) for the carrier gas-particle mixture (2) defining a flow-through chamber (4), wherein the flow-through body (3) has a curved chamber wall (5) for generating a circular flow and / or swirling flow of the carrier gas-particle mixture (3) as it flows over the chamber wall (5), wherein an inlet opening (6) for a carrier gas-particle mixture (2) and an outlet opening (7) for the carrier gas-particle mixture (2) are provided in the chamber wall (5), and the flow-through body (3) is otherwise closed and / or closable from the environment, wherein a carrier gas-particle mixture (2) can be supplied to the flow-through chamber (4) via the inlet opening (6),wherein the carrier gas-particle mixture (2) can be transported from the inlet opening (6) to the outlet opening (7) by forming a circular flow along the chamber wall (5) of the flow-through body (2) and can be discharged from the flow-through chamber (4) via the outlet opening (7).

2. Deagglomeration device (1) according to claim 1, characterized in that a tangential supply of the carrier gas-particle mixture (2) via the inlet opening (6) into the flow chamber (4) is provided.

3. Deagglomeration device (1) according to claim 1 or 2, characterized in that the inlet opening (6) is connected tangentially to the chamber wall (5).

4. Deagglomeration device (1) according to one of the preceding claims, characterized in that a tangential discharge of the carrier gas-particle mixture (2) via the outlet opening (7) from the flow chamber (4) is provided.

5. Deagglomeration device (1) according to one of the preceding claims, characterized in that the outlet opening (7) is connected tangentially to the chamber wall (5).

6. Deagglomeration device (1) according to one of the preceding claims, characterized in that the flow-through body (3) is designed as a rotary hollow body, in particular as a hollow cylinder.

7. Deagglomeration device (1) according to one of the preceding claims, characterized in that the flow body (3) has a particularly tangential connection area (16) to a connection line for the carrier gas-particle mixture (2) and for supplying the carrier gas-particle mixture (2) into the flow chamber (4) and a further particularly tangential connection area (17) to a connection line for the carrier gas-particle mixture (2) and for discharging the carrier gas-particle mixture (2) from the flow chamber (4).

8. Deagglomeration device (1) according to one of the preceding claims 1 to 6, characterized in that the flow-through body (3) has an inlet cylinder section (18) and an adjoining cone section (19), wherein the inlet cylinder section (18) has a preferably tangential connection region (26) for a connection line for the carrier gas-particle mixture (2) and for feeding the carrier gas-particle mixture (2) into the flow-through chamber (4) and the cone section (19) has an axial connection region (27) for a connection line for the carrier gas-particle mixture (2) and for discharging the carrier gas-particle mixture (2) from the flow-through chamber (4).

9. Deagglomeration device (1) according to one of the preceding claims, characterized in that the flow-through body (3) is free of internal components and / or free of mechanically and / or motor-driven and / or movable components and / or that the flow volume of the flow-through body corresponds to the rotation volume of the flow-through body (3).

10. Deagglomeration device (1) according to one of the preceding claims, characterized in that the connection area (16, 26) is connected and / or connectable to a sample application device and / or that the connection area (17, 27) is connected and / or connectable to a particle measuring device, in particular a particle measuring volume.

11. Deagglomeration device (1) according to one of the preceding claims, characterized in that the connection region (17, 27) is connected and / or connectable to a suction device arranged downstream of the flow-through body (3) in the flow direction of the carrier gas-particle mixture (2) for suctioning the carrier gas-particle mixture (2) through the flow-through chamber (4).

12. Deagglomeration device (1) according to one of the preceding claims, characterized in that the connection region (16, 26) is connected to a vibrating trough, wherein a particle sample is sucked in the region of the vibrating trough together with ambient air as a carrier gas and transported into the flow-through chamber (4).

13. Deagglomeration device (1) according to one of the preceding claims, characterized in that the chamber wall (5) has an embossing and / or is roughened.

14. Particle measuring device, in particular for determining grain size and grain shape information, further in particular by laser diffraction, image analysis and / or time-of-flight analysis, with at least one deagglomeration device (1) according to one of the preceding claims or with several deagglomeration devices (1) according to one of the preceding claims connected one behind the other or in parallel in a flow path of a carrier gas-particle mixture (2).

15. Particle measuring device according to claim 14, characterized in that a measuring, control and / or regulating device designed for automatic cleaning of the flow-through chamber (4), in particular for automatic time-dependent cleaning and / or for automatic cleaning depending on the flow resistance when flowing through the flow-through chamber (4) with the carrier gas-particle mixture (2), is provided.

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