EP3423178B1 - Mixer, system for applying a building material and method for producing a structure from building material - Google Patents

Description

The present invention relates to a mixer and a method of making a structure from building material using a mixer.

Conventionally, mixers with a drum in which an agitator shaft is arranged, which can be driven by a drive, are used to mix different components, which can be, for example, solid, liquid or powdery. The agitator shaft can be equipped with pins, for example, so that when the agitator shaft rotates, the material to be mixed is moved and mixed. Such a mixer is, for example, in the published application WO 2007/066362 A1 shown. With this horizontal continuous mixer, the material to be mixed is fed into the drum via an inlet, mixed there by pins on the agitator shaft, and finally discharged from the drum again via a lateral outlet. The pins on the agitator shaft of such a mixer can be designed and arranged in such a way that the material to be mixed is moved by the pins in a predetermined direction in the drum. However, it has been shown that such a movement of the material to be mixed through the drum of the mixer only works sufficiently well with certain viscosities of the material to be mixed. In such a system, the conveying of the mixed material to an outlet of the mixer is insufficient, particularly in the case of highly viscous mixed materials. As a result, the mixer can become clogged and its function is impaired.

An object of the present invention is therefore to avoid the disadvantages of the known devices. In this case, a mixer is to be made available which can also continuously mix and convey substances with a higher viscosity. The mixer should also be easy to use and inexpensive to use.

document DE 10 2007 004 768 A1 discloses a system according to the preamble of claim 1.

The object is initially solved by a system according to claim 1.

This solution offers the advantage that mixed materials with a higher viscosity can also be continuously mixed and conveyed. For example, when mixing pumpable concrete with concrete admixtures, it is desirable for the mixture to reach a certain viscosity so that it can be used directly to produce a concrete structure. The conveying device according to the invention in the mixer also allows for such applications to convey the material to be mixed continuously and directly from an inlet of the drum to an outlet of the drum without the mixer being blocked by higher-viscosity mixture materials and thus failing in its function.

In an advantageous embodiment, the conveying device is arranged directly after the agitator shaft, so that the mixture mixed by the agitator shaft can be picked up directly by the conveying device and conveyed out of the drum through the outlet.

This has the advantage that mixed materials with high or rapidly increasing viscosity can be conveyed because the mixed material is immediately conveyed out of the drum due to the arrangement of the conveying device directly adjacent to the agitator shaft, so that the mixer can be prevented from being blocked by the mixed material.

In an advantageous exemplary embodiment, the agitator shaft is equipped with pins, so that when the agitator shaft rotates, a material to be mixed in the drum is moved by the pins. This has the advantage that efficient and uniform mixing of the various components can be achieved. Furthermore, through a targeted arrangement and design of the pins, both thorough mixing and conveying of the material to be mixed in the drum can be influenced.

Such stirrer shafts with pins are particularly suitable for mixing components with large grain sizes, for example grain sizes of 2 to 10 mm. This can be, for example, aggregates such as stones, gravel or sand. In addition, such a mixer is also suitable for mixing asymmetric substances such as mixed goods with fiber additives (for example carbon fibers, metal fibers or plastic fibers).

In an alternative exemplary embodiment, the agitator shaft is not fitted with pins, but is designed, for example, as a helical agitator, disk agitator or inclined blade agitator.

In an advantageous exemplary embodiment, the conveying device and the agitator shaft are arranged on the same drive shaft, with this drive shaft being able to be driven by the drive. This has the advantage that an inexpensive and robust device results.

In an alternative embodiment, the conveyor device and the agitator shaft are arranged on two separate drive shafts, the conveyor device being arranged on a first drive shaft and the agitator shaft on a second drive shaft, so that the conveyor device and agitator shaft can be driven at different speeds. Such an arrangement has the advantage that the mixing and the conveying of the material to be mixed can be adjusted separately from one another. In this way, mixing and conveying that is optimal for the respective purpose can be achieved through a specifically adjustable mixing capacity and conveying capacity. For example, for a first application, low mixing combined with high delivery capacity and/or delivery at high pressure can be advantageous, and for a second application thorough mixing combined with low delivery capacity and/or delivery at low pressure can be advantageous.

In an advantageous embodiment, the agitator shaft and the conveyor device are arranged side by side in the drum, with the agitator shaft being arranged on a first drum section and the conveyor device on a second drum section, and with the inlet on the first Barrel section and the outlet are arranged on the second barrel section.

In an advantageous development, the first drum section with the agitator shaft arranged therein forms between 50% and 90%, preferably between 60% and 85%, particularly preferably between 70% and 80%, of a volume of the drum. It has been shown that by dividing the drum in this way, an optimal mixing performance can be achieved with a desired conveying performance of the mixer. According to the invention, the conveyor element is designed as a conveyor screw. According to the invention, the screw conveyor has at least two windings. Such a screw conveyor has the advantage that high-viscosity mixtures can also be conveyed in the drum and can also be conveyed out of the drum through the outlet with a desired pressure.

In an advantageous development, more than two windings can be formed. In addition, the windings differ in their extent in the direction of the drive shaft, the windings becoming narrower towards one end of the conveyor device. As a result, a delivery pressure of the delivery device can be changed, depending on the orientation of the constriction of the windings.

In a further advantageous development, a cross section of a shaft of the conveyor device can be designed to be variable in the direction of the drive shaft. In this way, a volume for the material to be mixed becomes narrower towards one end of the conveying device. As a result, a delivery pressure of the delivery device can be changed, depending on the orientation of the narrowing of the volume for the mixed material.

In order to mix and convey a first component and a second component with one another, only one inlet or else two or more inlets can be arranged on the drum. The components can be brought together, for example, before they are fed into the drum, or the components can be fed into the drum via separate inlets and only in the drum are mixed together. Depending on the number and arrangement of the inlets, the agitator shaft and any agitator elements arranged thereon, such as pins for example, can be designed differently.

In an advantageous embodiment, the drum comprises a first inlet and a second inlet, with a feed device being arranged at the first inlet. The provision of such a feed device at one of the inlets has the advantage that powdered components can thereby be fed to the feed device efficiently and in a controlled manner.

In an advantageous development, the feed device comprises a hopper for receiving a powdery component, a second drive and a second agitator shaft coupled thereto and arranged in the hopper. This has the advantage that this powdery component can be introduced continuously into the drum of the mixer without clogging.

In an advantageous development, the second agitator shaft comprises radially arranged agitator blades, which are arranged in an inlet area of the funnel, and the second agitator shaft has an axially aligned stirring rod, which is radially offset from an axis of rotation of the agitator shaft and is arranged in an outlet area of the funnel. Such a feed device offers the advantage that the stirring blades can be used to convey the powdered component in a controlled manner through an input area of the funnel, with the radially offset stirring rod preventing the powdered component from blocking the output area of the funnel.

Alternatively, only stirring blades without a stirring rod or a stirring rod without stirring blades can also be arranged on the stirring shaft.

In an advantageous embodiment that is not claimed, a component that is supplied to the system via the supply device can be supplied using a gravimetric method. In contrast to a volumetric method, this has the advantage that a supplied mass of one component can be set precisely, as a result of which a more precise mixing result can be achieved.

In an advantageous embodiment not claimed, an additional second conveying device is arranged in the drum on the same axis as the agitator shaft and the conveying device in order to guide a first component introduced into the drum via the inlet away from the inlet before the first component is mixed with further components.

This is particularly advantageous when powdery components are introduced into the drum via the inlet, because these are advantageously to be mixed with other components in a section remote from the inlet, in order to avoid clogging of the inlet.

A system for applying a building material according to claim 1 offers the advantage that, for example, building structures can be built efficiently and cost-effectively as a result. The advantage of the arrangement proposed here lies in particular in the fact that the components are only mixed with one another shortly before the building material is applied. This is made possible by the fact that the mixer is arranged so that it can be moved via the traversing device, so that it can be brought to the position at which the building material is to be applied. Due to the direct application of the building material after the mixing process, a high-viscosity building material, such as concrete, can be used in the mixer without this high-viscosity building material having to be further conveyed or processed.

In an advantageous development, the first component is a pumpable building material such as concrete, and the second component is a pumpable substance which contains a building material additive such as a concrete additive.

In an advantageous development, the building material additive is a setting accelerator and/or a hardening accelerator.

The use of a pumpable building material and a building material additive offers the advantage that both the pumpable building material and the building material additive can be transported in a simple manner from a container to the mixer, with the mixing of these two substances creating a highly viscous building material which can be directly Manufacture of a building structure can be used.

In an advantageous embodiment that is not claimed, the traversing device is designed to be movable in the manner of a 3D printer, so that the system can be used to construct structures from the building material.

Such systems in the form of 3D printers offer the advantage that entire structures can be produced from building material, such as building walls or the like. In this case, no formwork is necessary, and therefore the shape of the structure can also be selected much more freely.

Furthermore, a method for producing a structure from building material is proposed, comprising the steps of: mixing a pumpable building material, in particular concrete, and a pumpable substance which contains a building material additive, in particular a concrete additive, with a mixer; and applying the mixture with a traversing device.

In an advantageous, non-claimed embodiment, the concrete additive is a setting accelerator and/or hardening accelerator.

In an advantageous development, the mixer is operated during mixing at a speed of more than 500 revolutions per minute, preferably at a speed of more than 650 revolutions per minute, particularly preferably at a speed of more than 800 revolutions per minute, particularly preferably at one Speed of more than 1000 revolutions per minute.

Operating the mixer at high speeds has the advantage that mixes with a high or rapidly increasing viscosity (such as concrete with a setting accelerator and/or hardening accelerator) can be mixed as efficiently and quickly as possible and then conveyed out of the mixer without the mixer being damaged blocked and failed in its function.

In addition, such high speeds offer the advantage that not only can the materials be thoroughly mixed, but structures in the mixture can also be broken up, which can be desirable, for example, in the case of pelleted raw materials that have to be broken up and/or broken up .

In tests, pumpable concrete was mixed with a setting or hardening accelerator at speeds between 200 and 2000 revolutions per minute. It was found that when mixing at speeds below 500 revolutions per minute, a sufficiently homogeneous or smooth mixture is not achieved, so that the pumpable concrete and the pumpable accelerator mix insufficiently with one another. This led to hardening and hardening behavior that was difficult to control, since the insufficiently homogeneous mixture has areas with an above-average amount of additive and areas with a correspondingly insufficient amount of additive. This can lead to blockages in the mixer and/or imperfections in the applied mixture, such as areas of insufficient strength after a certain time after leaving the mixer.

• Erstens werden der Beton und der Beschleuniger besser durchmischt, was eine kontrollierbareres Erstarrungs- bzw. Erhärtungsverhalten zur Folge hat.
• Zweitens wird der Beton stärker aufgebrochen, sodass der Beschleuniger auf einer grösseren Oberfläche des Betons einwirken kann, was eine schnellere und besser kontrollierbare Reaktion zwischen Beton und Beschleuniger zur Folge hat.
• Drittens wird mehr Energie in das Gemisch eingetragen, was eine stärkere Erwärmung von Beton und Beschleuniger zur Folge hat, was wiederum den Erstarrungs- bzw. Erhärtungsprozess beschleunigt.

Tests have shown that higher speeds have the following effects:

• First, the concrete and accelerator are better mixed, resulting in more controllable setting or hardening behavior.
• Second, the concrete is broken up more, allowing the accelerator to act on a larger surface area of the concrete, resulting in a faster and more controllable reaction between the concrete and the accelerator.
• Thirdly, more energy is introduced into the mixture, which results in greater heating of the concrete and accelerator, which in turn accelerates the solidification or hardening process.

The effects described above were increasingly observed up to a speed of 2000 revolutions per minute.

In further tests, pumpable concrete to which fibers had been added was mixed with an accelerator at different speeds according to the method described above. Speeds of more than 900 revolutions per minute have proven to be advantageous here, because the fibers had to be broken up in addition to the concrete.

In a further advantageous development, when the mixture is applied with the traversing device, the average residence time of the mixture in the drum is less than 10 seconds, preferably less than 7 seconds, particularly preferably less than 4 seconds.

The mean dwell time of the mixture in the drum is the average time that a particle stays in the drum (from the inlet of the drum to the outlet of the drum).

An above-mentioned advantageous average residence time of at most a few seconds has the advantage that a mix of high or rapidly increasing viscosity can be conveyed, such as pumpable concrete mixed with setting accelerators and/or hardening accelerators.

In an advantageous, non-claimed embodiment, when the mixture is applied, the mixture is applied in a plurality of layers lying at least partially on top of one another.

In an advantageous further development, a new layer of the mixture is only superimposed on an existing layer during application when the existing layer has sufficient strength to retain its original shape.

In an advantageous development, at least partially overlapping layers of the mixture are continuously built up during application, so that the structure is built up from building material in the manner of a 3D printer.

Such methods, in which the mixture is applied and then at least partially overlaid by a renewed application of mixture, offer the advantage that entire structures can be produced from building material, such as building walls or the like. In comparison to conventional methods, such methods offer the advantage that no formwork is necessary and that the shape of the structure can therefore also be selected much more freely.

Fig. 1:

schematische Darstellung eines beispielhaften Mischers mit einer Fördervorrichtung;

Fig. 2:

schematische Darstellung eines beispielhaften Mischers mit einer Fördervorrichtung und mit einer Zuführvorrichtung über einem Einlass;

Fig. 3A:

schematische Darstellung einer beispielhaften Zuführvorrichtung;

Fig. 3B:

schematische Darstellung einer beispielhaften Zuführvorrichtung;

Fig. 4:

schematische Darstellung eines Mischers zur Vermischung einer ersten Komponente und einer zweiten Komponente;

Fig. 5:

schematische Darstellung eines beispielhaften Systems zum Applizieren eines Baustoffes; und

Fig. 6:

schematische Darstellung einer beispielhaften Fördervorrichtung.

Details and advantages of the invention are described below using exemplary embodiments and with reference to schematic drawings. Show it:

Figure 1:

schematic representation of an exemplary mixer with a conveyor device;

Figure 2:

schematic representation of an exemplary mixer with a conveyor device and with a feed device over an inlet;

Figure 3A:

schematic representation of an exemplary feeding device;

Figure 3B:

schematic representation of an exemplary feeding device;

Figure 4:

schematic representation of a mixer for mixing a first component and a second component;

Figure 5:

schematic representation of an exemplary system for applying a building material; and

Figure 6:

schematic representation of an exemplary conveyor device.

In 1 an exemplary mixer 1 is shown. The mixer 1 has a drive 3, a drum 2, an agitator shaft 4 and a conveyor device 5. The drum 2 has two inlets 6 and one outlet 7. The inlets 6 are in a first drum section 10, in which the agitator shaft is arranged and the outlet 7 is located on a second drum section 11, in which the conveyor device 5 is also arranged.

In this exemplary embodiment, two inlets 6 are arranged on drum 2 . In an alternative embodiment not shown, however, the drum 2 has only one inlet. The components to be mixed can already be brought together before they are conveyed into the drum 2 via the inlet.

The conveying device 5 is arranged directly after the agitator shaft 4 so that the mixture mixed by the agitator shaft 4 can be picked up directly by the conveying device 5 and conveyed through the outlet 7 out of the drum 2 .

In this exemplary embodiment, the conveying device 5 is designed as a conveying screw. The screw conveyor in this exemplary embodiment has two complete windings 9. Depending on the desired conveying capacity, the screw conveyor can be dimensioned or designed differently. The conveying device 5 and the stirring shaft 4 are arranged on the same axis in the drum 2 . In this exemplary embodiment, the agitator shaft 4 is equipped with pins 8 so that when the agitator shaft rotates, a material to be mixed in the drum is moved by the pins 8 . In 2 an exemplary mixer 1 is again shown. In contrast to mixer 1 off 1 a feeding device 12 is arranged at one of the inlets 6 in this mixer. This feed device 12 is suitable, for example, for introducing a powdered component into the drum 2 of the mixer 1 evenly and without clogging.

In the Figures 3A and 3B is the feeding device 12, which in 2 is arranged at one of the inlets 6, shown in more detail. The feed device 12 has a second drive 13 and a second agitator shaft 16. The second agitator shaft 16 is arranged in a funnel 19 so that it can rotate. The hopper 19 has an entrance portion 14 and an exit portion 15. Here, stirring blades 17 are arranged on the second stirring shaft in the entrance portion of the hopper 19, and a stirring rod 18 is arranged in the exit portion 15 of the hopper 19 on the second stirring shaft 16. The agitator blades 17 are arranged radially on the second agitator shaft, so that they can convey a powdery component through the inlet area 14 of the hopper 19 . The stirring rod 18 is axially aligned with respect to the second stirring shaft 16 and radially offset from an axis of rotation of the stirring shaft 16 . As a result, this stirring rod 18 can prevent the outlet region 15 of the funnel 19 from becoming clogged.

In 4 an exemplary mixer 1 is again shown with a feed device 12 at one of the inlets. A first component 20 and a second component 22 are fed to the mixer 1 via a first feed 21 and a second feed 23 respectively. For example, the first component 20 can be a powdery component, which is fed via the first feed 21 into the hopper of the feed device 12, and the second component 22 can be, for example, a liquid or a pumpable substance, which is fed via the second feed 23 directly into the drum of the mixer 1 is guided. After the mixing process in the drum of the mixer 1, the mixture is conveyed by the conveying device 5 through the outlet 25 of the mixer.

In figure 5 a system 30 for applying a building material is shown. The system 30 includes a traversing device 31 and a first component 32 and a second component 33. The first component 32 and the second component 33 are fed to the mixer 1 via a first feed 34 and a second feed 35 . The mixer 1 includes an outlet 36 through which the building material can be applied. In order to be able to apply the building material at a desired location, the mixer 1 can be moved by the moving device 31 . For this purpose, the traversing device 31, as shown in this exemplary embodiment, can have an arm which is designed to be movable. For example, a multi-articulated arm can be used to allow a more varied movement of the mixer 1 in space.

In alternative exemplary embodiments that are not shown, the traversing device 31 is designed as a crane, as a robot, as a mobile device on wheels or caterpillars, or as a 3D printer.

In 6 an exemplary embodiment of a conveyor device 5 is shown. In this example, initially more than two turns 9 are formed. In addition, the windings 9 differ in their extent in the direction of the drive shaft, the windings 9 becoming narrower towards one end of the conveying device 5 . As a result, a delivery pressure of the delivery device 5 can be changed, depending on the alignment of the constriction of the windings 9.

Furthermore, in this example, a cross section of a shaft of the conveyor device 5 is designed to be variable in the direction of the drive shaft. A volume for the material to be mixed becomes narrower towards one end of the conveying device 5 . As a result, a delivery pressure of the delivery device 5 can be changed, depending on the alignment of the constriction of the volume for the material to be mixed.

Claims (6)

1. System (30) for applying a construction material, the system (30) comprising

   a moving device (31),

   a first component (32),

   a second component (33), and

   a mixer (1) for mixing the first component (32) and the second component (33), the mixer (1) comprising a drum (2) having at least one inlet (6) and one outlet (7), a drive (3), a stirring shaft (4) for mixing a mix, said stirring shaft (4) being arranged in the drum (2) and being coupled to the drive (3), wherein a conveying device (5) is arranged in the drum (2), said conveying device (5) being arranged on one and the same axis as the stirring shaft (4), wherein the conveying element (5) is in the form of a screw conveyor, wherein the screw conveyor has at least two turns (9), wherein the mixer (1) is arranged on the moving device (31) and is movable thereby, such that it is able to be moved in each case to that position at which the construction material is intended to be applied,

   wherein the first component (32) and the second component (33) are able to be fed to the mixer (1) in order to produce the construction material, and

   wherein the construction material produced from the components (32, 33) is able to be applied via the outlet (36) of the mixer (1), characterized in that the turns (9) have different extents in the direction of the stirring shaft (4), wherein the turns (9) become tighter towards one end of the conveying device (5).
2. System (30) according to Claim 1, wherein the conveying device (5) directly adjoins the stirring shaft (4) such that the mix mixed by the stirring shaft (4) is able to be collected directly by the conveying device (5) and is able to be conveyed out of the drum (2) through the outlet (7).
3. System (30) according to either of the preceding claims, wherein the conveying device (5) and the stirring shaft (4) are arranged on one and the same driveshaft, and wherein said driveshaft is drivable by the drive (3).
4. System (30) according to one of the preceding claims, wherein the stirring shaft (4) and the conveying device (5) are arranged next to one another in the drum (2), wherein the stirring shaft (4) is arranged in a first drum section (10) and the conveying device (5) is arranged in a second drum section (11), and wherein the at least one inlet (6) is arranged in the first drum section (10) and the outlet (7) is arranged in the second drum section (11).
5. System (30) according to Claim 4, wherein the first drum section (10) with the stirring shaft (4) arranged therein forms between 50% and 90%, preferably between 60% and 85%, particularly preferably between 70% and 80%, of a volume of the drum (2).
6. System (30) according to one of the preceding claims, wherein the drum (2) comprises a first inlet (6) and a second inlet (6), and wherein a feeding device (12) is arranged at the first inlet (6).

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