DE102021004703A1 - Device and method for mixing particles with a wetting agent - Google Patents

Abstract

The invention relates to a device for mixing particles with a wetting agent, preferably for mixing particles with a binder in the course of the production of material panels, the device (1) having a tubular base body (2) in which a coaxially arranged mixing shaft (13 ) with radially outgoing mixing elements (14) is arranged rotatably as a drum mixer, with an inlet opening (15) and an outlet opening for the particle stream (17) being arranged at a distance from one another on the base body (2) and at least at the inlet opening (15) a transition element (18 ) for transferring the particle stream (17) arriving from a preceding device into the inlet opening (15) of the base body (2). The object of the present invention is to create a device and a method for operating the device, with which it is possible to extend the usage cycles in a generic device. The invention for the device consists in that a cleaning device is arranged on or for at least one of the inner sides (1619) of the transition element (18).

Description

The invention relates to a device for mixing particles with a wetting agent, preferably for mixing particles with a binder in the course of the production of material panels, according to the preamble of patent claim 1.
The invention also relates to a method for mixing particles with a wetting agent according to the preamble of patent claim 23.

Such a device for mixing particles with a wetting agent is also called a glue mixer or drum mixer. These are preferably used for mixing or distributing a binder on the particles when the particles are pressed in a press to produce panels of material. Such glue mixers are from the prior art, for example from EP 1 602 463 B1 or DE 20 2012 105 060 U1 , known.

In these devices, in a tubular base body, in which a coaxially arranged mixing shaft with radially outgoing mixing elements is rotatably driven, a stream of particles is introduced into an inlet opening on the base body, mixed along the mixing shaft by the mixing elements and transported through the base body and via a downstream arranged exit opening issued for further processing. On the one hand, it is common to mix or spray the particles within the device with binder. It is also known, for example, to apply the binder in or immediately after the inlet opening.

Depending on the process specifications, however, it is also known to feed the binder to the particle flow in an upstream area and to further intensify the mixing of the binder with the particles in the drum mixer or to add additives or further amounts of binder.

These devices have basically proven themselves in operation, but can still be fundamentally improved for large-scale industrial use.

The object of the present invention is to create a device and a method for operating the device, with which it is possible to extend the usage cycles in a generic device. In an extension of the invention, automatic cleaning protocols should be able to be established in critical areas, which can help to avoid cumbersome and manual maintenance or cleaning when the device is shut down or in the event of forced shutdowns due to emergencies.

A generic device, from which the invention is based, comprises a tubular base body in which a coaxially arranged mixing shaft with radially extending mixing elements is rotatably arranged as a drum mixer,
an inlet opening and an outlet opening for the particle stream being arranged at a distance from one another on the base body and a transition element for transferring the particle stream arriving from a preceding device into the inlet opening of the base body being arranged at least on the inlet opening.

The transition element is therefore to be understood in such a way that it is usually part of the mixer and forms the interface between the inlet opening on the base body and a device or a transfer area of the particle flow from a previous device, for example a metering device, a conveyor device or the like.

The object of the invention is achieved in that a cleaning device is arranged on or for at least one of the inner sides of the transition element. This should be suitable for detaching adhering particles on at least one inner side of the transition element.

The particle flow is formed from a large number of particles that are guided through the device or the system.

• - durch Umlenkung oder Einwirkung des Partikelstroms,
• - durch die Bewegung eines Maschinenelements und/oder
• - durch die räumliche Nähe der Mischelemente zu einem Teil des Übergangselements

bewirkt werden kann.The cleaning device is particularly preferably designed in such a way that cleaning

• - by deflection or effect of the particle flow,
• - by the movement of a machine element and/or
• - Due to the spatial proximity of the mixing elements to a part of the transition element

can be effected.

In a preferred embodiment, a displaceable or pivotable element can be arranged as a cleaning device on one or more walls, preferably geometrically shaped like an associated wall. Provision can be made for this element to be adjacent to or in engagement with the walls.

In this case, the element can change in a simple manner at predetermined distances from one wall to the other wall, thereby causing caking in the cross section of the transition remove elements. Particularly preferably, the adjoining walls can be scraped off or large-area caking broken off in cross section. The possible overall cleaning of the contour and the self-cleaning effect during operation by the particle flow is particularly advantageous. The displacement mechanism or its guidance can be arranged in the undercut of the entry opening of the transition element, which is generally smaller than the clear cross section of the transition element.

Alternatively or cumulatively, the corresponding element is shifted asymmetrically, not parallel to a wall but obliquely and/or at an angle to a plane of the direction of flow in order to enhance or enable the cleaning effect.

In a further alternative or additional embodiment, the cleaning device can be designed as an endlessly circulating belt instead of or on a wall, preferably with an associated seal and/or belt cleaning system. The moving belt allows caking to be removed either sporadically or continuously. If the clear cross-section is reduced on all sides due to caking, it could be sufficient if only one wall, which is as large as possible, is equipped in such a way that the cleaning effect is adequate. This circumstance also applies to other equivalent exemplary embodiments.

Alternatively or cumulatively, in a further exemplary embodiment, one or more preferably rotatable rollers, particularly preferably with an associated seal and/or roller cleaning system, can be arranged as a cleaning device instead of or on a wall. The advantages and possibilities correspond to the previous exemplary embodiment.

With a coaxial arrangement of the roller to the mixing shaft, the circumference of the roller is particularly preferably arranged on the circumference of the cylindrical base body. This makes it possible for the mixing elements to clean part of the roller as it drives past.

Alternatively or cumulatively, in a further exemplary embodiment, an element can be arranged as a cleaning device on or instead of a wall, which element is suitable for changing its geometric shape at predetermined time intervals. For example, this can be a flexible element, an inflatable tube, a net or a bendable metal sheet. A flexible element can be, for example, a chain, a net or a bendable metal sheet, which is converted from its first geometric shape as a wall into another geometric shape, for example a bulge, by means of appropriate adjusting means. Due to the change in shape, the caking usually breaks off or is brought close to the mixing elements or the particle flow that support the cleaning effect. In the course of this, a hose or a bag can also be arranged on the wall or as a wall, which is pumped up pneumatically or hydraulically by introducing a fluid. The following shape change gives the cleaning effect.

• • Das Übergangselement kann in seinem Querschnitt senkrecht zur Partikelströmung im Wesentlichen reckeckig ausgeführt sein.
• • Das Übergangselement kann der Kontur der Eintrittsöffnung des Grundkörpers entsprechend angepasst sein.
• • Am Übergangselement kann am Eintritt der Partikelströmung ein Verbindungselement angeordnet sein.
• • Zwischen einem Verbindungselement und der Eintrittsöffnung des Grundkörpers kann zumindest eine kurze Wandung, eine gegenüberliegende längere Wandung parallel zur Mischwelle sowie zwei diese Wandungen verbindenden und im Wesentlichen gleichförmige Wandungen zur Bildung des Querschnittes angeordnet, welcher mithin im Wesentlichen rechteckig ausgeführt sein kann.
• • Das Verbindungselement kann eintrittsseitig mit einer kreisförmigen Öffnung für den Partikelstrom und/oder als Flansch ausgeführt sein.
• • Zwischen dem Verbindungselement und der oder den Wandungen können Übergangsbleche angeordnet sind, die linear oder konkav geformt die Öffnung an den Querschnitt des Übergangselements anpassen. Dies dient insbesondere zur Vermeidung von Strömungswirbeln und somit von Anbackungen.
• • Der reale und/oder der theoretischer Querschnitt des Übergangselement kann sich in Richtung des Partikelstromes zumindest teilweise vergrößern.

The following features can be used alternatively or cumulatively in one of the above or in a separate embodiment:

• • The cross section of the transition element can be designed to be essentially rectangular perpendicular to the particle flow.
• • The transition element can be adapted to the contour of the entry opening of the base body.
• • A connecting element can be arranged on the transition element at the inlet of the particle flow.
• • Between a connecting element and the inlet opening of the base body, at least one short wall, an opposite longer wall parallel to the mixing shaft and two essentially uniform walls connecting these walls can be arranged to form the cross section, which can therefore be essentially rectangular.
• • The connecting element can be designed with a circular opening for the particle flow on the inlet side and/or as a flange.
• Transition plates can be arranged between the connecting element and the wall or walls, which adapt the opening to the cross section of the transition element in a linear or concave manner. This serves in particular to avoid flow vortices and thus caking.
• • The real and/or the theoretical cross-section of the transition element can at least partially increase in the direction of the particle flow.

The features are listed below specifically for a preferred and special exemplary embodiment, but they can also, if applicable, be combined with the previously mentioned exemplary embodiments.
In this particular embodiment, at least one element can be used as a cleaning device for a rectangular cross section of the transition element ment can be arranged on or along the long wall such that it can pivot along a pivot axis arranged coaxially with the mixing shaft.
By swiveling in, on the one hand the caking can be removed in a large area of the cross section, and the swiveling in is preferably carried out until the mixing elements on the mixing shaft carry out a cleaning effect on the element.
The pivotable element can be the wall itself or part of a type of double wall.

Thus, the cleaning effect can be brought about by the deflection of the particle flow, by the movement of the element per se and/or by the physical proximity of the mixing elements to the pivotable element.

The axis of rotation of the element on the wall is preferably arranged closer to the inlet opening and/or the longer element can be pivoted in or out along the long wall in the cross section.

The pivoting angle of the element along the pivoting axis can preferably be limited by the position of the normal wall and/or the radius of the rotating mixing elements.

The long wall can preferably be arranged tangentially on the base body and particularly preferably perpendicular to the horizontal and/or at the level of the mixing shaft.

Particularly preferably, the element can be arranged essentially parallel to the particle flow in a first rest position and in a second position near or at the radius of the base body, with the mixing elements preferably being suitable for removing caking on the element in the second position.

Alternatively or cumulatively, a cover that swivels along can be arranged at the swiveling-out end of the element, with the swiveling-out element preferably resulting in the shape of a circular sector together with the cover. This results in the possibility of creating a cover that prevents particles from getting behind the element and blocking the path on the way back and/or particles escaping from the transition element.

In this context, it can be advantageous if a scraper is arranged, preferably stationary on the wall and/or stationary on the transition element, for cleaning the cover.

Alternatively or cumulatively, lateral cleaning means can be arranged on the cover and/or on the element, which also clean the adjacent walls of the transition element.

• • die Schwenkachse in einem Bereich von 10° bis 30°, bevorzugt um die 20°, angeordnet ist, wenn ausgehend von Zentrum der Mischwelle die Eintrittsöffnung einen Quadranten von 0° bis 90° überstreicht.
• • die Höhe der langen Wandung nicht mehr als 125%, bevorzugt nicht mehr als 117,5%, höchst bevorzugt nicht mehr als 112,5% des Radius des Grundkörpers 2 beträgt,
• • die Höhe der kurzen Wandung nicht mehr als 25%, bevorzugt nicht mehr als 17,5%, höchst bevorzugt nicht mehr als 12,5% des Radius des Grundkörpers 2 beträgt und/oder
• • die Eintrittsöffnung am Umfang des Grundkörpers einen Öffnungswinkel von kleiner 100°, bevorzugt kleiner 90°, besonders bevorzugt von kleiner 80° überstreicht.

The following geometric or spatial features have proven to be advantageous in the embodiment just discussed here with a rectangular cross section of the transition element and can each be used alternatively or cumulatively to one another:

• • the pivot axis is arranged in a range from 10° to 30°, preferably around 20°, if, starting from the center of the mixing shaft, the inlet opening covers a quadrant from 0° to 90°.
• • the height of the long wall is no more than 125%, preferably no more than 117.5%, most preferably no more than 112.5% of the radius of the base body 2,
• • the height of the short wall is no more than 25%, preferably no more than 17.5%, most preferably no more than 12.5% of the radius of the base body 2 and/or
• • the inlet opening on the circumference of the base body covers an opening angle of less than 100°, preferably less than 90°, particularly preferably less than 80°.

In addition, the pivotable element can be designed to be displaceable in the radial direction to the pivot axis or variable in its extent and is preferably guided along a slot link. The variable extension or displacement makes it possible to clean a larger area of the transition element.

The displaceable element can also be designed to be partially permeable to the particle flow, in particular to simplify cleaning during operation.

Alternatively or cumulatively, means for cleaning, preferably rubber lips and/or scraping edges, can be arranged on the element on the sides of the adjacent walls.

This ends the feature listing of the particular embodiment above.

In a further exemplary embodiment, the cleaning device or the movable element can be designed as a closing element for the transition element. This means that cleaning work can be carried out in the area in front of the device, for example in a chute, without dirt or caking from this area getting into the drum mixer. Alternatively, the locking element can also be used as a type of fire protection door in order to seal off different parts of the system from one another.

In another separate exemplary embodiment, a sensor system for determining the free cross section and/or for measuring the flow of the particle stream can be arranged, preferably in the transition element. In this way, the need for cleaning can be determined and, if necessary, cleaning can be triggered. The flow measurement can determine, for example, whether the particle flow begins to pulsate due to a cross section that is too narrow or whether there are back pressure effects.

As a rule, but not necessarily, a transition element with a substantially rectangular cross-section perpendicular to the particle flow is provided for receiving the particle flow via the inlet opening, for transferring the particle flow arriving from a preceding device into the base body.

The transition element is correspondingly adapted to the inlet opening on the base body and has on the other side a connection element for the previous device that supplies or discharges the particle stream.

The preceding device can be a glue tower for spraying the particle flow with a binder, a dosing device or a simple transport device such as a conveyor belt. Between the connecting element and the inlet opening of the base body, at least one short wall and an opposite longer wall are arranged parallel to the mixing shaft, as well as two essentially uniform walls connecting these walls to form the cross section open to the particle flow.

The transition element can thus also be understood as a filling funnel, which, however, preferably does not have a narrowing funnel shape in order to avoid blockages in the particle flow.

The transition element can best be compared as a machine element which connects a previous part of the plant with the base body of the glue mixer or the introduction opening and is suitable for creating a transition between the two parts of the plant for the cross-section to be flowed through.

Means for introducing the wetting agent could be provided in the transition element itself.

The transition element should preferably only be used for the passage and, if necessary, the geometric adjustment of the particle flow.

The transition element can be designed in several parts in the direction of flow.

The transition element can be inclined with respect to the horizontal and/or the axis of the mixing shaft. This can also affect only parts or certain walls of the transition element.

The base body of the drum mixer or the device can be arranged essentially horizontally or inclined to the horizontal. This can then be used as a accumulation mixer or as a self-cleaning drum mixer.

The invention further relates to a method for mixing particles with a wetting agent in a device. This can preferably be used to mix particles with a binder in the course of the production of material panels. The particles are mixed with the wetting agent in the device in a tubular base body by means of a coaxially arranged mixing shaft with radially outgoing mixing elements. For this purpose, a particle stream is introduced into the base body via an inlet opening and discharged via a spaced-apart outlet opening, the particle stream being introduced into the inlet opening of the base body through a transition element.

The invention for the method consists essentially in the fact that particles adhering to the particle stream are removed in the cross section or on the inside of the transition element by means of a cleaning device.

In a preferred embodiment, the cleaning in the transition element can be carried out automatically and/or manually activated during operation, preferably at predetermined intervals, with the cleaning being carried out particularly preferably when the device is shut down or when it is running empty.

Alternatively or cumulatively, the free cross section and/or the flow rate per unit time of the particle flow can be measured in the transition element. In particular, it can be provided that the measured values are used to control and/or activate the cleaning device.

The transition element can either be due to the connection geometry of the inlet the mixer, the input area of the mixer itself or as an additional component.

The above device features are usually process-related, in particular due to the cleaning function or in connection with the cleaning effect, so that the device features can also be regarded as process features.

Further advantageous measures and refinements of the subject matter of the invention emerge from the dependent claims and the following description with the drawing.

• 1 in vier schematischen und zugehörigen Schnitten die Darstellung einer Vorrichtung zur Benetzung von Partikeln mit einem Benetzungsmittel,
• 2 eine Draufsicht auf das Übergangselement mit dahinter liegender Eintrittsöffnung des Grundkörpers mit einem ersten Ausführungsbeispiel für die Reinigungsvorrichtung,
• 3 eine schematische Seitenansicht einer senkrecht zur Zeichenebene liegenden Mischwelle im Schnitt mit einem weiteren Ausführungsbeispiel für die Reinigungsvorrichtung,
• 4 eine schematische Seitenansicht einer senkrecht zur Zeichenebene liegenden Mischwelle im Schnitt mit einem weiteren Ausführungsbeispiel für die Reinigungsvorrichtung,
• 5 eine schematische Seitenansicht einer senkrecht zur Zeichenebene liegenden Mischwelle im Schnitt mit einem weiteren Ausführungsbeispiel für die Reinigungsvorrichtung,
• 6 eine schematische Seitenansicht einer senkrecht zur Zeichenebene liegenden Mischwelle im Schnitt mit einem weiteren Ausführungsbeispiel für die Reinigungsvorrichtung,
• 7 eine schematische Seitenansicht einer senkrecht zur Zeichenebene liegenden Mischwelle im Schnitt mit einer besonders bevorzugten Ausführungsform für die Reinigungsvorrichtung und
• 8 eine erweiterte Ausführungsform der Reinigungsvorrichtung nach 7.

Show it:

• 1 in four schematic and associated sections, the representation of a device for wetting particles with a wetting agent,
• 2 a top view of the transition element with the inlet opening of the base body behind it, with a first exemplary embodiment of the cleaning device,
• 3 a schematic side view of a perpendicular to the plane of the mixing shaft in section with a further embodiment of the cleaning device,
• 4 a schematic side view of a perpendicular to the plane of the mixing shaft in section with a further embodiment of the cleaning device,
• 5 a schematic side view of a perpendicular to the plane of the mixing shaft in section with a further embodiment of the cleaning device,
• 6 a schematic side view of a perpendicular to the plane of the mixing shaft in section with a further embodiment of the cleaning device,
• 7 a schematic side view of a perpendicular to the plane of the mixing shaft in section with a particularly preferred embodiment for the cleaning device and
• 8th an extended embodiment of the cleaning device 7 .

Essentially, the same reference numbers indicate the same machine elements in the figures.

In 1 is shown in four schematic and associated sections, the representation of a device 1 for wetting particles with a wetting agent. In the left side view of a cylindrical base body 2, the axis of the mixing shaft 13 runs parallel to the plane of the drawing and coaxially to the base body 2. The particle stream 17 enters a transition element 18 via a funnel of a previous system part that is not shown in detail and is conveyed through the transition element 18 to the Inlet opening 15 of the cylindrical base body 2 is supplied. The mixing elements 14 operatively connected to the mixing shaft 13 mix the particle stream 17 to which a wetting agent is supplied at any point in or before the entry into the device 1 . At the same time, the mixing elements 14 transport the particle stream 17 in the direction of an outlet opening (not shown) in the cylindrical base body 2. The middle view on the right shows a section through the transition element 18 and the cylindrical base body 2, with the mixing shaft 13 being perpendicular to the plane of the drawing. The mixing elements 14 rotate through the mixing shaft 13 and have an effective range that results from the radius 11 . The transition element 18 is arranged on the inlet opening 15 and has a rectangular cross section in the exemplary embodiment, see the sectional drawing at the bottom right, which is formed by the walls 3 , 4 and 5 . In this case, the wall 3 is short in comparison to the opposite wall 4 in height, but itself is usually rectangular. The walls 5 connecting these two walls 3 and 4 are perpendicular to the mixing shaft and follow the cylindrical base body 2 or the inlet opening 15 on a narrow side. The two walls 5 are generally symmetrical to one another. Opposite the inlet opening 15 of the base body, the transition element 18 preferably has a connecting element 16 . This can be designed as a flange in order to connect the transition element 18 to previous parts of the system.

2 shows a plan view of the transition element 18 with the inlet opening 15 of the base body 2 lying behind it, which is essentially rectangular in the drawing, with a first exemplary embodiment of a cleaning device in the transition element 18. The cleaning device can be designed as a machine element with a movable cross section. In the present example, this is designed as a wall 5*, which essentially has the same contour as a wall 5 and can be moved parallel to one of the two walls 5 along a suspension shown with double lines from left to right and vice versa. Provision can preferably be made for the edges of the displaceable wall 5* lying against the walls 3 and 4 to clean them by means of a scraper strip or a rubber strip. The intermittent movement of the wall 5 by the particle stream 17 results in a self-cleaning effect on the wall 5*. The broken off caking become the particle stream 17 fed back and broken up or ground up by the mixing process. In an alternative, a wall 4* is designed or arranged accordingly.

3 shows a further embodiment of the cleaning device in a schematic side view of a mixing shaft lying perpendicular to the plane of the drawing. Here, a wall 5* is provided in addition to the cleaning device 2 or mounted alone in such a way that it can be displaced parallel to a wall 5 and by sliding past it detaches any caking on the wall 5 . Appropriate sealing means should be provided between the wall 4 and the wall 5 so that the particles of the particle stream 17 cannot escape.

Alternatively or cumulatively 4 a wall 3 * be arranged, which also as per 2 is arranged perpendicular to the associated wall 3 slidably. Based on the short wall 3, it would be advantageous if the displacement mechanism follows the curve of the inlet opening 15 and is not arranged horizontally or parallel to the connecting element 16.

Alternatively or cumulatively, 5 on one of the walls, preferably on the long wall 4, a roller 19 may be arranged. This can rotate in or counter to the particle flow 17 passing by and is cleaned when it exits the transition element 18, preferably by means of a seal. Advantageously, the roller can be designed conically in such a way that it gives the particle flow 17 a tendency in the direction of the outlet opening of the base body 2 . The roller can be rotated continuously or intermittently.

Alternatively or cumulatively, 6 as a cleaning device, a flexible element can be arranged as or on a wall, preferably on the wall 4. This flexible element can lie flat against the wall 4 in the rest state or form the wall 4. For the cleaning effect, the flexible element is bulged or changed in its geometry, causing the caking to crumble off. In the exemplary embodiment, an airbag 20 is arranged for this purpose, which is inflated explosively or more slowly as required, and during or through the expansion of its shape (dashed line) the caking breaks off or bursts off. Depending on the volume and geometry of the airbag, it can preferably be designed in such a way that it follows the contour of the transition element 18 and does not engage in the radius 14 of the mixing elements 14 .

The 7 and 8th show a particularly preferred embodiment of the cleaning device in two variants in a schematic side view with a mixing shaft in section perpendicular to the plane of the drawing. Here, an element 6 is arranged on a pivot axis 8 and can be pivoted out of a first rest position into a cleaning position along a pivot angle 7. Caking that has accumulated in the cross section of the transition element 18 is removed by pivoting out. The element 6 is preferably swiveled out far enough that it rests on or near the radius 11 of the mixing elements 14, which, when passing by, can clean the caking on the element 6, which in the rest position is on the inside, i.e. the surface of the mixing element in the direction of the cross section Elements 6, may have formed. Depending on the design, this cleaning can be carried out in idle mode. In the resting state (dashed line), the cross section is preferably completely free and the element 6 rests against the wall 4 . Alternatively, an opening (not shown) can also be released. This can be of particular advantage if the element 6 is also intended to serve as a closure element which almost or almost seals the cross section. Foreign material or cleaning agents from the previous parts of the system or during manual cleaning or maintenance can be removed from the transition element 18 so easily without getting into the cylindrical base body 2 . The inlet opening 15 is shown as a broken line along the contour of the base body 2 .

In an alternative preferred embodiment, the element 6 is designed as a kind of circular segment, with a cover 9 being provided which prevents particles from entering behind the element 6 . This can in turn be cleaned by a scraper 10 when swiveling back into the rest position (dashed line). The cover does not necessarily have to be circular; it can also be formed by a preferably resilient metal sheet, as long as the sealing effect in the area of the scraper 10 is ensured.

As in 8th In a higher-quality embodiment, the element 6 can not only be rotated by a pivot angle 7, but also either change its length (e.g. telescoping) or be displaced along a connecting link on the pivot axis 8. This makes it possible to clean a larger part of the cross section of the transition element 18 . The dashed variants show either the rest position or a far extended maximum position of the element 6 close to the mixing elements 14. The opening already made above would be shown here if the element 6 in the direction of the cleaning position is moved, a locking effect by the element 1619 could also be generated more easily in this way.

reference list

1

contraption

2

body (cylindrical)

3

wall (short)

4

wall (long)

5

wall (2x)

6

element

7

swivel angle

8th

pivot axis

9

cover

10

scraper

11

Radius of 14

12

opening

13

mixed shaft

14

mixing element

15

entry opening

16

fastener

17

particle stream

18

transition element

19

roller

20

air bag

QUOTES INCLUDED IN DESCRIPTION

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

Patent Literature Cited

• EP 1602463 B1 [0002]
• DE 202012105060 U1 [0002]

Claims (25)

Device for mixing particles with a wetting agent, preferably for mixing particles with a binding agent in the course of the production of material panels, the device (1) having a tubular base body (2) in which a coaxially arranged mixing shaft (13) with radially outgoing mixing elements (14) is rotatably arranged as a drum mixer, with an inlet opening (15) and an outlet opening for the particle stream (17) being arranged at a distance from one another on the base body (2) and at least at the inlet opening (15) a transition element (18) for transferring the particle stream (17) arriving from a preceding device is arranged in the inlet opening (15) of the base body (2), characterized in that a cleaning device is arranged on or for at least one of the inner sides of the transition element (18), which is suitable for detaching adhering particles on at least one inner side of the transition element (18) . device after claim 1 , characterized in that the cleaning device is suitable to bring about by deflection or action of the particle flow (17), by the movement of a machine element and/or by the spatial proximity of the mixing elements (14) to a part of the transition element (18). Device according to at least one of the preceding claims, characterized in that a displaceable or pivotable element is arranged as a cleaning device on one or more walls (3, 4, 5), preferably shaped like a wall (3*, 4*, 5*). Device according to at least one of the preceding claims, characterized in that an endlessly circulating belt, preferably with an associated seal and/or belt cleaning, is arranged as the cleaning device instead of or on a wall (3, 4, 5). Device according to at least one of the preceding claims, characterized in that one or more rotatable rollers (19), preferably with an associated seal and/or roller cleaning, are arranged as cleaning device instead of or on a wall (3, 4, 5). Device according to the preceding claim, characterized in that when the roller (19) is arranged coaxially to the mixing shaft (14), the circumference of the roller (19) bears against the circumference of the cylindrical base body (2). Device at least according to one of the preceding claims, characterized in that an element (6) is arranged as a cleaning device on or instead of a wall (3, 4, 5), which is suitable for changing its geometric shape at predetermined time intervals, preferably a flexible one Element (6), an inflatable tube, a net or a bendable metal sheet. Device at least according to one of the preceding claims, characterized in that the transition element (18) is essentially rectangular in its cross section perpendicular to the particle flow (17), that the transition element (18) corresponds to the contour of the inlet opening (15) of the base body (2) adjusted accordingly; that a connecting element (16) is arranged on the transition element (18) at the inlet of the particle flow (17); and/or that between a connecting element (16) and the inlet opening (15) of the base body (2) at least one short wall (3), an opposite longer wall (4) parallel to the mixing shaft (13) and two of these walls (3, 4) connecting and substantially uniform walls (5) are arranged to form the cross-section. Device at least according to one of the preceding claims, characterized in that the connecting element (16) is designed on the inlet side with a circular opening (12) for the particle flow (17) and/or as a flange and/or that between the connecting element (16) and the or the walls (3, 4, 5) transition plates are arranged, which are linearly or concavely shaped and adapt the opening (12) to the cross section of the transition element (18) and/or that an increasing real and/or theoretical cross section of the transition element (18 ) is arranged in the direction of the particle flow (17). Device according to at least one of the preceding claims, characterized in that at least one element (6) as a cleaning device is arranged on or on the long wall (4) so that it can pivot along a pivot axis (8) arranged coaxially with the mixing shaft (13). device after claim 10 , characterized in that the axis of rotation (8) on the wall (4) is arranged closer to the inlet opening (15) and/or the longer element (6) which or along the long wall (4) can be pivoted in or out of the cross section. device after claim 10 or 11 , characterized in that a pivot angle (7) of the element (6) along the pivot axis (8) by the wall (4) and / or the radius (11) of the mixing elements (14) is limited. Device at least according to one of Claims 10 until 12 , characterized in that the long wall (4) is arranged tangentially on the base body (2). Device at least according to one of Claims 10 until 13 , characterized in that the element (6) is arranged in a first rest position essentially parallel to the particle flow (17) and in a second position in the vicinity of or at the radius (11) of the base body (2), preferably in the second position the mixing elements (14) are suitable for removing caking on the element (6). Device at least according to one of Claims 10 until 14 , characterized in that at the pivoting end of the element (6) there is arranged a cover (9) which pivots with it, the pivoting element (6) preferably resulting in the shape of a circular sector together with the cover (9). Device at least the preceding claim 15 , characterized in that for cleaning the cover (9) a scraper (10), preferably stationary on the wall (4) and / or stationary on the connecting element (16) is arranged. Device at least according to one of Claims 10 until 16 , characterized in that the pivot axis (8) is arranged in a range of 10° to 30°, preferably around 20°, if, starting from the center of the mixing shaft (13), the inlet opening (15) has a quadrant of 0° to 90 ° overswept. Device at least according to one of Claims 10 until 17 , characterized in that the height of the long wall (3) is not more than 125%, preferably not more than 117.5%, most preferably not more than 112.5% of the radius of the base body (2), that the height of short wall (3) is no more than 25%, preferably no more than 17.5%, most preferably no more than 12.5% of the radius of the base body (2) and/or that the inlet opening (15) is on the circumference of the base body (2) covers an opening angle of less than 100°, preferably less than 90°, particularly preferably less than 80°. Device at least according to one of Claims 10 until 18 , characterized in that the element (6) is additionally arranged to be displaceable in the radial direction to the pivot axis (8), preferably guided along a groove link. Device at least according to one of Claims 10 until 19 , characterized in that means for cleaning, preferably rubber lips and/or scraping edges, are arranged on the element (6) on the sides of the adjacent walls (5). Device at least according to one of Claims 10 until 20 , characterized in that the movable element (6) is designed as a closure element for the transition element (18). Device at least according to one of Claims 10 until 21 , characterized in that preferably in the transition element (18) a sensor for determining the free cross-section and / or for flow measurement of the particle flow is arranged. Method for mixing particles with a wetting agent in a device, preferably for mixing particles with a binder in the course of the production of material panels, wherein in the device (1) in a tubular base body (2) a coaxially arranged mixing shaft (13) with radial outgoing mixing elements (14), the particles are mixed with the wetting agent, a particle stream (17) entering the base body (2) via an inlet opening (1) and being discharged via a spaced-apart outlet opening, and the particle stream (17) passing through a transition element ( 18) is introduced into the inlet opening (15) of the base body (2), characterized in that particles adhering to the cross section or to the inner sides of the transition element (18) are removed by means of a cleaning device. Method according to the preceding claim, characterized in that the cleaning in the transition element (18) is carried out automatically and/or manually during operation, preferably at predetermined intervals, the cleaning being carried out particularly preferably when the device is shut down or when it is running empty. Method according to a previous method claim, characterized in that in the transition element (18) of the free cross-section and / o the flow rate per unit time of the particle stream (17) is measured and that the measured values are used to control and/or activate the cleaning device.

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