EP3659699B1 - System for applying a building material - Google Patents

Description

The present invention relates to a system for applying a building material.

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

One object of the present disclosure is therefore to avoid the disadvantages of the known devices. The aim is to provide a mixer which can continuously mix and convey substances with a higher viscosity. The mixer should also be easy to handle and cost-effective to operate.

The object is initially achieved by a mixer comprising a drum with at least one inlet and one outlet. The mixer further comprises a drive and a stirring shaft for mixing a mixture, wherein the stirring shaft arranged in the drum is coupled to the drive. Furthermore, the mixer comprises Mixer a conveying device which is arranged in the drum and which is arranged on the same axis as the stirring shaft.

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

In an advantageous embodiment, the conveying device is arranged directly adjacent to the agitator shaft, so that the mixture mixed by the agitator shaft can be directly grasped 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 by the conveying device being arranged directly next to the agitator shaft, so that the mixer can be prevented from becoming blocked by the mixed material.

In an advantageous embodiment, the agitator shaft is fitted with pins so that when the agitator shaft rotates, the mixed material in the drum is moved by the pins. This has the advantage that efficient and even mixing of the various components can be achieved. Furthermore, a targeted arrangement and design of the pins can influence both the mixing and the conveyance of the mixed material in the drum.

Such stirring shafts with pins are particularly suitable for mixing components with large grain sizes, for example grain sizes of 2 to 10 mm.

These can be additives such as stones, gravel or sand. Such a mixer is also suitable for mixing asymmetrical materials such as mixed goods with fiber additives (e.g. carbon fibers, metal fibers or plastic fibers).

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

In an advantageous embodiment, the conveying device and the agitator shaft are arranged on the same drive shaft, whereby this drive shaft can be driven by the drive. This has the advantage that it results in a cost-effective and robust device.

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

In an advantageous embodiment, the agitator shaft and the conveyor device are arranged next to each other in the drum, wherein the agitator shaft is arranged on a first drum section and the conveyor device on a second drum section, and wherein the inlet is arranged on the first drum section and the outlet are arranged on the second drum 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 capacity of the mixer. In an advantageous embodiment, the conveying element is designed as a conveyor screw. In an advantageous development, the conveyor screw has at least one, preferably at least two turns. Such a conveyor screw has the advantage that it can also convey highly viscous mixed materials in the drum and can also be conveyed out of the drum through the outlet with a desired pressure.

In an advantageous further development, more than two windings can be formed. In addition, the windings can differ in their extent in the direction of the drive shaft, with the windings becoming narrower towards one end of the conveyor device. This allows a conveying pressure of the conveyor device to 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 conveying device can be designed to be variable in the direction of the drive shaft. In this case, a volume for the mixed material becomes narrower towards one end of the conveying device. As a result, a conveying pressure of the conveying 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, only one inlet or two or more inlets can be arranged on the drum. The components can, for example, be brought together before they are fed into the drum, or the components can be fed into the drum via separate inlets and only mixed in the drum. Depending on the number and arrangement of the inlets, the agitator shaft and any agitating elements arranged on it, such as pins, can be designed differently.

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

In an advantageous development, the feed device comprises a funnel for receiving a powdery component, a second drive and a second agitator shaft coupled thereto and arranged in the funnel. This has the advantage that this powdery component can be continuously introduced 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 agitator rod which is radially offset from a rotational axis of the agitator shaft and which is arranged in an outlet area of the funnel. Such a feed device offers the advantage that the powdery component can be conveyed in a controlled manner through an inlet area of the funnel by the agitator blades, the powdery component being prevented from blocking the outlet area of the funnel by the radially offset agitator rod.

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

In an advantageous embodiment, a component that is fed into the system via the feed device can be fed using a gravimetric method. In contrast to a volumetric method, this has the advantage that the mass of one component fed can be precisely adjusted, which allows a more precise mixing result to be achieved.

In an advantageous embodiment, 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 powdered components are introduced into the drum via the inlet, because they are advantageously to be mixed with other components in a section remote from the inlet in order to avoid clogging of the inlet.

According to the invention, a system for applying a building material according to claim 1 is proposed.

A system according to the preamble of claim 1 is made of JP H 0262205 - A known.

The inventive

The system comprises a moving device, a first component and a second component. The system also comprises a mixer for mixing the first component and the second component, the mixer being arranged on the moving device and being movable by it. The first component and the second component can be fed to the mixer to produce the building material. The building material produced from the components can also be applied via the outlet of the mixer. The mixer described here is used as the mixer.

Such a system for applying a building material offers the advantage that, for example, building structures can be built efficiently and cost-effectively. The advantage of the arrangement proposed here is in particular that the components are only mixed together 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 displacement device, so that it can be brought to the position at which the building material is to be applied. By applying the building material directly after the mixing process, a highly viscous building material, such as concrete, can be used in the mixer without this highly viscous building material needs to be further transported or processed.

According to the invention, the first component is a pumpable concrete and the second component is a pumpable substance containing a concrete admixture, wherein the concrete admixture 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 easily transported from a container to the mixer, whereby the mixing of these two substances creates a highly viscous building material which can be used directly to produce a building structure.

According to the invention, the displacement device is designed to be movable in the manner of a 3D printer, so that structures can be built up from the building material by the system.

Such systems, such as 3D printers, offer the advantage that entire structures can be made from building materials, such as building walls or similar. No formwork is necessary, and the shape of the structure can therefore be chosen much more freely.

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 a speed of more than 1000 revolutions per minute.

Operating the mixer at high speeds offers the advantage that mixes with high or rapidly increasing viscosity (such as concrete with setting accelerator and/or hardening accelerator) can be mixed as efficiently and quickly as possible and then pumped out of the mixer without the mixer becoming blocked and failing to function.

In addition, such high speeds offer the advantage that they not only achieve a good mixing of the materials, but also allow structures in the mix to be broken up, which can be desirable, for example, with pelletized raw materials that need to be broken down and/or disintegrated.

In tests, pumpable concrete was mixed with setting or hardening accelerators 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 was not achieved, so that the pumpable concrete and the pumpable accelerator did not mix sufficiently with each other. This led to setting or hardening behavior that was difficult to control, since the insufficiently homogeneous mixture had areas with an above-average amount of additive and areas with correspondingly too little additive. This can lead to blockages in the mixer and/or defects in the applied mixture, such as areas with insufficient strength after a certain time after leaving the mixer.

The tests have shown that higher speeds have the following effects:
Firstly, the concrete and the accelerator are better mixed, which results in a more controllable setting or hardening behavior. Secondly, the concrete is broken up more so that the accelerator can act on a larger surface of the concrete, which results in a faster and more controllable reaction between the concrete and the accelerator. Thirdly, more energy is introduced into the mixture, which results in the concrete and accelerator heating up more, which in turn accelerates the setting or hardening process.

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

In further tests, pumpable concrete mixed with fibers was mixed with accelerator at different speeds according to the method described above. Here, speeds of over 900 revolutions per minute proved to be advantageous because in addition to the concrete, the fibers also had to be broken up.

In a further advantageous development, when applying the mixture with the displacement device, an 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 average residence time of the mixture in the drum is the length of time that a particle stays in the drum on average (from the inlet of the drum to the outlet of the drum).

An above-mentioned advantageous average residence time of a maximum of a few seconds has the advantage that it enables a mix with a high or rapidly increasing viscosity to be pumped, such as pumpable concrete mixed with setting accelerator and/or hardening accelerator.

In an advantageous embodiment, when applying the mixture, the mixture is applied in several layers that are at least partially superimposed.

In an advantageous further development, during application, an existing layer is only overlaid with a new layer of the mixture when the existing layer has a sufficiently high strength to maintain its original shape.

During application, layers of the mixture are continuously built up, at least partially overlapping each other, so that the structure is constructed from building material in the manner of a 3D printer.

Such processes, in which a mixture is applied and then at least partially covered by a further application of the mixture, offer the advantage that entire structures can be made from building material, such as building walls or similar. In comparison to conventional processes, such processes offer the advantage that no formwork is necessary and that the shape of the structure can therefore be chosen 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 embodiments and with reference to schematic drawings. They show:

Fig.1:

schematic representation of an exemplary mixer with a conveying device;

Fig. 2:

schematic representation of an exemplary mixer with a conveying device and with a feeding device above an inlet;

Fig. 3A:

schematic representation of an exemplary feeding device;

Fig. 3B:

schematic representation of an exemplary feeding device;

Fig.4:

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

Fig.5:

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

Fig.6:

Schematic representation of an exemplary conveying device.

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

In this exemplary embodiment, two inlets 6 are arranged on the 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 adjacent to the agitator shaft 4, so that the mixed material mixed by the agitator shaft 4 can be directly grasped by the conveying device 5 and conveyed out of the drum 2 through the outlet 7.

In this embodiment, the conveying device 5 is designed as a conveyor screw. The conveyor screw in this embodiment has two complete turns 9. Depending on the desired conveying capacity, the conveyor screw can be dimensioned or designed differently. The conveying device 5 and the agitator shaft 4 are arranged on the same axis in the drum 2. In this embodiment, the agitator shaft 4 is equipped with pins 8, so that when the agitator shaft rotates, a mixed material in the drum is moved by the pins 8.

In Fig.2 An exemplary mixer 1 is shown. In contrast to mixer 1 from Fig.1 In this mixer, a feed device 12 is arranged at one of the inlets 6. This feed device 12 is suitable, for example, for introducing a powdery component into the drum 2 of the mixer 1 evenly and without clogging.

In the Fig. 3A and 3B is the feeding device 12, which in Fig.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 stirring shaft 16. The second stirring shaft 16 is arranged so as to be rotatable in a funnel 19. The funnel 19 has an inlet area 14 and an outlet area 15. Stirring blades 17 are arranged on the second stirring shaft in the inlet area of the funnel 19, and a stirring rod 18 is arranged on the second stirring shaft 16 in the outlet area 15 of the funnel 19. The stirring blades 17 are arranged radially on the second stirring shaft so that they can convey a powdery component through the inlet area 14 of the funnel 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. This stirring rod 18 can therefore protect the outlet area 15 of the funnel 19 from becoming blocked.

In Fig.4 is again shown an exemplary mixer 1 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. For example, the first component 20 can be a powdery component which is fed into the funnel of the feed device 12 via the first feed 21, and the second component 22 can be, for example, a liquid or a pumpable substance which is fed directly into the drum of the mixer 1 via the second feed 23. 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 Fig.5 a system 30 for applying a building material is shown. The system 30 comprises a displacement device 31 as well as 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 comprises an outlet 36 through which the building material can be applied. In order to be able to apply the building material to a desired location, the mixer 1 can be moved by the displacement device 31. For this purpose, the displacement device 31 can have an arm, as shown in this embodiment, which is designed to be movable. For example, a multi-joint arm can be used to enable a more diverse movement of the mixer 1 in space.

In alternative embodiments not shown, the displacement device 31 is designed as a crane, as a robot or as a mobile device on wheels or crawlers. According to the invention, the displacement device is designed as a 3D printer.

In Fig.6 an exemplary embodiment of a conveying device 5 is shown.

In this example, more than two windings 9 are initially formed. In addition, the windings 9 differ in their extent in the direction of the drive shaft, with the windings 9 becoming narrower towards one end of the conveyor device 5.

This allows a delivery pressure of the conveying device 5 to be changed depending on the orientation of the constriction of the windings 9.

Furthermore, in this example, a cross-section of a shaft of the conveying device 5 is designed to be variable in the direction of the drive shaft. In this case, a volume for the mixed material becomes narrower towards one end of the conveying device 5. As a result, a conveying pressure of the conveying device 5 can be changed depending on the orientation of the narrowing of the volume for the mixed material.

Claims (10)

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), wherein the mixer (1) has

   a drum (2) with at least one inlet (6) and an outlet (7),

   a drive (3),

   a stirring shaft (4) for mixing a mix, said stirring shaft (4) being arranged in the drum (2) and coupled to the drive (3), and

   a conveying device (5) which is arranged in the drum (2) and which is arranged on one and the same axis as the stirring shaft (4),

   wherein the mixer (1) is arranged on the moving device (31) and can be moved thereby,

   wherein the first component (32) and the second component (33) can be fed to the mixer (1) to produce the construction material, and

   wherein the construction material produced from the components (32, 33) can be applied via the outlet (36) of the mixer (1), wherein the first component (32) is a pumpable concrete, and

   wherein the second component (33) is a pumpable substance which contains a concrete admixture, wherein the concrete admixture is a solidification accelerator and/or a hardening accelerator,
   characterized in that the moving device (31) is designed to be movable in the manner of a 3D printer such that structures can be constructed from the construction material using the system (30).
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) can be directly collected by the conveying device (5) and can 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 drive shaft, and wherein this drive shaft can be driven 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 on a first drum portion (10) and the conveying device (10) is arranged on a second drum portion (11), and wherein the at least one inlet (6) is arranged on the first drum portion (10) and the outlet (7) is arranged on the second drum portion (11).
5. System (30) according to Claim 4, wherein the first drum portion (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 conveying element (5) is designed as a screw conveyor.
7. System (30) according to Claim 6, wherein the screw conveyor has at least one, preferably at least two, turns (9) .
8. 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).
9. System (30) according to one of the preceding claims, wherein the mixer (1) is designed for a speed of more than 500 revolutions per minute.
10. System (30) according to one of the preceding claims, wherein the system is designed in such a way that, during an application of the mixture with the moving device (13), an average residence time of the mixture in the drum (2) is less than 10 seconds.

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