EP3646943A2 - Method for producing a structure from building material - Google Patents

Abstract

A method for producing a structure from building material, comprising the steps: mixing a pumpable building material and a pumpable substance which contains a building material additive with a mixer (1), the mixer (1) comprising: a drum (2) with at least one Inlet (6) and an outlet (7), a drive (3), an agitator shaft (4) for mixing a mixture, which is arranged in the drum (2) and which is coupled to the drive (3), and a conveying device (5) which is arranged in the drum (2) and which is arranged on the same axis as the agitator shaft (4); andapplying the mixture with a traveling device (31).

Description

The present invention relates to a mixer and a method for producing a structure from building material using a mixer.

Mixers with a drum are conventionally used to mix different components, which can be solid, liquid or powder, for example, in which a stirring shaft is arranged, which can be driven by a drive. The agitator shaft can be equipped with pins, for example, so that the mix is moved and mixed when the agitator shaft rotates. Such a mixer is for example in the published patent 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 side 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 works sufficiently well only with certain viscosities of the material to be mixed. In such a system, in particular in the case of highly viscous mixed materials, the conveyance of the mixed material to an outlet of the mixer is insufficient. The consequence of this is that the mixer can become blocked and its function is impaired.

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

The object is first achieved by a mixer comprising a drum with at least one inlet and one outlet. The mixer further comprises a drive and an agitator shaft for mixing a material to be mixed, the agitator shaft arranged in the drum being coupled to the drive. Furthermore, the Mixer a conveyor device which is arranged in the drum and which is arranged on the same axis as the agitator shaft.
This solution has the advantage that it can also continuously mix and convey mixes with higher viscosity. For example, when mixing pumpable concrete with concrete admixtures, it is desirable for the mix to reach a certain viscosity so that it can be used directly to produce a concrete structure. The conveyor device according to the invention 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 more viscous mixing materials and thus failing in its function.

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

This has the advantage that mixes with a high or strongly increasing viscosity can be conveyed, because the mix is immediately conveyed out of the drum by the directly adjoining arrangement of the conveyor to the agitator shaft, so that a blockage of the mixer by the mix can be prevented.

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

Such agitator shafts with pins are particularly suitable for mixing components with large grain sizes, for example grain sizes from 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 asymmetrical substances such as, for example, mixed materials with fiber additives (for example carbon fibers, metal fibers or plastic fibers).

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

In an advantageous exemplary embodiment, the conveying device and the agitator shaft are arranged on the same drive shaft, this drive shaft being drivable by the drive. This has the advantage that it results in an inexpensive and robust device.

In an alternative exemplary 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 conveying of the mixed material can be set separately from one another. In this way, mixing and conveying that is optimal for the respective purpose can be achieved by means of a specifically adaptable mixing capacity and conveying capacity. For example, for a first application, a slight mixing with a simultaneously high delivery rate and / or delivery with high pressure may be advantageous, and for a second application a strong mixing with a simultaneously low delivery rate and / or delivery with low pressure may be advantageous.

In an advantageous embodiment, the agitator shaft and the conveying device are arranged side by side in the drum, the agitator shaft being arranged on a first drum section and the conveying device on a second drum section, and the inlet 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 stirring 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 delivery performance of the mixer. In an advantageous embodiment, the conveyor element is designed as a screw conveyor. In an advantageous development, the screw conveyor has at least one, preferably at least two turns. Such a screw conveyor has the advantage that it can also convey highly viscous mixes in the drum and can also be conveyed from the drum through the outlet at a desired pressure.

In an advantageous development, more than two turns can be formed. In addition, the turns can differ in their dimensions in the direction of the drive shaft, the turns becoming 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 turns.

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. A volume for the mix becomes narrower towards one end of the conveyor. As a result, a conveying pressure of the conveying device can be changed, depending on the alignment of the narrowing of the volume for the mix.

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

In an advantageous exemplary embodiment, the drum comprises a first inlet and a second inlet, 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 powdery components can thereby 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 to it and arranged in the funnel. This has the advantage that this powdery component can be continuously introduced into the mixer drum without clogging.

In an advantageous development, the second agitator shaft comprises radially arranged agitator blades, which are arranged in an input region of the funnel, and wherein the second agitator shaft has an axially aligned stirrer rod, which is radially offset from an axis of rotation of the agitator shaft and is arranged in an output region of the funnel. Such a feeding device offers the advantage that the powdered component can be conveyed through an input region of the funnel in a controlled manner by the stirring blades, the powdery component being prevented from blocking the output region of the funnel by the radially offset stirring 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 to the system via the feed device can be fed using a gravimetric method. In contrast to a volumetric method, this has the advantage that a supplied mass of the one component can be set precisely, as a result of which a more precise mixing result can 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 lead 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 should advantageously be mixed with other components in a section away from the inlet in order to avoid clogging of the inlet.

Furthermore, a system for applying a building material is proposed, the system comprising a moving device, a first component and a second component. The system further comprises a mixer for mixing the first component and the second component, the mixer being arranged on the travel device and being movable by the latter. The first component and the second component for producing the building material can be fed to the mixer. Furthermore, the building material generated from the components can be applied via the outlet of the mixer. The mixer according to the invention and 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 with one another shortly before the application of the building material. This is made possible by the fact that the mixer is arranged such that it can be moved via the travel 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 highly viscous building material, such as concrete, can be used in the mixer without this highly viscous building material having to be conveyed or processed further.

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

In an advantageous development, the building material additive is a solidification 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 from a container to the mixer in a simple manner, the mixing of these two substances resulting in a highly viscous building material which is used directly for Manufacturing a building structure can be used.

In an advantageous embodiment, the traversing device is designed to be movable in the manner of a 3-D printer, so that structures can be built up from the building material by means of the system.

Systems of this type in the form of 3-D printers offer the advantage that entire structures can be produced from building material, such as building walls or the like. No formwork is required, which means that the structure can be shaped much more freely.

Furthermore, a method for producing a structure from building material is proposed, comprising the steps: 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 embodiment, the concrete additive is a setting accelerator and / or setting accelerator.

In an advantageous development, the mixer is operated 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 Speed of more than 1000 revolutions per minute.

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

In addition, such high speeds offer the advantage that not only can thorough mixing of the materials be achieved, but structures in the mix can also be broken up, which can be desirable, for example, in the case of pelletized raw materials which have to be broken down and / or broken up .

In experiments, pumpable concrete with solidification or hardening accelerators were mixed 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 one another. This led to hardening or hardening behavior, which is difficult to control, since the insufficiently homogeneous mixture has 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 to defects in the applied mixture, such as areas with insufficient strength after a certain time after leaving the mixer.

The tests have shown that the following effects occur as a result of higher speeds:
First, the concrete and the accelerator are mixed better, which results in more controllable setting or hardening behavior. Second, 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 more heating of the concrete and accelerator, 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 experiments, pumpable concrete, which was mixed with fibers, was mixed with accelerator at different speeds according to the method described above. Here, speeds of over 900 revolutions per minute have proven to be advantageous because here, in addition to the concrete, the fibers also had to be broken up.

In a further advantageous development, when the mixture is applied with the travel 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 remains in the drum (from the inlet of the drum to the outlet of the drum) on average.

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

In an advantageous embodiment, when the mixture is applied, the mixture is applied in a plurality of at least partially superimposed layers.

In an advantageous development, an existing layer is only overlaid with a new layer of the mixture when the existing layer is sufficiently strong to maintain its original shape.

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

Such methods, in which mixture is applied and then at least partially overlaid by a renewed application with 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 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:

Fig. 1:

schematic representation of an exemplary mixer with a conveyor;

Fig. 2:

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

Fig. 3A:

schematic representation of an exemplary feed device;

3B:

schematic representation of an exemplary feed 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 conveyor.

In Fig. 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 located 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 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, 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 conveyor device 5 is then arranged directly on the agitator shaft 4, so that the mixed material mixed by the agitator shaft 4 can be detected directly by the conveyor device 5 and can be conveyed out of the drum 2 through the outlet 7.

In this exemplary embodiment, the conveyor device 5 is designed as a screw conveyor. The screw conveyor in this exemplary embodiment has two complete turns 9. Depending on the desired conveying capacity, the screw conveyor can be dimensioned or designed differently. The conveyor device 5 and the agitator 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 mixture is moved in the drum by the pins 8.

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

In the 3A and 3B is the feeder 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 agitator shaft 16. The second agitator shaft 16 is rotatably arranged in a funnel 19. The funnel 19 has an input region 14 and an output region 15. In this case, stirring blades 17 are arranged on the second stirring shaft in the input region of the funnel 19, and a stirring rod 18 is arranged in the output region 15 of the funnel 19 on the second stirring shaft 16. The stirring blades 17 are arranged radially on the second stirring shaft so that they can convey a powdery component through the input region 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. As a result, this stirring rod 18 can prevent the outlet region 15 of the funnel 19 from becoming blocked.

In Fig. 4 again shows 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 respective first feed 21 and a second feed 23. 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 a liquid or a pumpable substance, for example, which flows directly through the second feed 23 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 Fig. 5 A system 30 for applying a building material is shown. The system 30 comprises a travel device 31 and a first component 32 and one 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 at a desired location, the mixer 1 can be moved by the moving device 31. For this purpose, the displacement 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 the mixer 1 to move in a more varied manner in space.

In alternative, not illustrated exemplary embodiments, 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 Fig. 6 An exemplary embodiment of a conveyor device 5 is shown. In this example, more than two turns 9 are initially formed. In addition, the turns 9 differ in their extent in the direction of the drive shaft, the turns 9 narrowing 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 orientation of the narrowing of the turns 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 mixed material 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 narrowing of the volume for the mix.

Claims (15)

A method of making a structure from building material, comprising the steps of: Mixing a pumpable building material and a pumpable substance, which contains a building material additive, with a mixer (1), the mixer (1) comprising: a drum (2) with at least one inlet (6) and one outlet (7), a drive (3), an agitator shaft (4) for mixing a material to be mixed, which is arranged in the drum (2) and which is coupled to the drive (3), and a conveying device (5) which is arranged in the drum (2) , and which is arranged on the same axis as the agitator shaft (4); and Applying the mixture with a traversing device (31). The method of claim 1, wherein the pumpable building material is concrete, and wherein the building material additive contains a concrete additive. A method according to claim 2, wherein the concrete admixture is a setting accelerator and / or a setting accelerator. Method according to one of the preceding claims, wherein the conveyor device (5) connects directly to the agitator shaft (4), so that the mixed material mixed by the agitator shaft (4) can be detected directly by the conveyor device (5) and through the outlet (7) from the drum (2) is eligible. Method according to one of the preceding claims, wherein the conveyor device (5) and the agitator shaft (4) are arranged on the same drive shaft, and wherein this drive shaft can be driven by the drive (3). Method according to one of the preceding claims, wherein the stirring shaft (4) and the conveying device (5) are arranged side by side in the drum (2), the stirring shaft (4) on a first drum section (10) and the conveying device (5) on one second drum section (11) are arranged, and the at least one inlet (6) being arranged on the first drum section (10) and the outlet (7) being arranged on the second drum section (11). Method according to claim 6, wherein the first drum section (10) with the stirring shaft (4) arranged therein has between 50% and 90%, preferably between 60% and 85%, particularly preferably between 70% and 80%, of a volume of the drum (2 ) forms. Method according to one of the preceding claims, wherein the conveyor element (5) is designed as a screw conveyor. The method of claim 8, wherein the screw conveyor has at least one, preferably at least two turns (9). Method according to one of the preceding claims, wherein the drum (2) comprises a first inlet (6) and a second inlet (6), and wherein a feed device (12) is arranged at the first inlet (6). Method according to one of the preceding claims, wherein the mixer (1) is operated during mixing at a speed of more than 500 revolutions per minute. Method according to one of the preceding claims, wherein when the mixture is applied with the movement device (31), an average residence time of the mixture in the drum is less than 10 seconds. Method according to one of the preceding claims, wherein when applying the mixture, the mixture is applied in several at least partially superimposed layers. The method of claim 13, wherein when applying an existing layer is only superimposed with a new layer of the mixture when the existing one Layer has a high enough strength to maintain an original shape. Method according to one of claims 13 or 14, wherein during the application at least partially overlapping layers of the mixture are built up continuously, so that the structure is built up from building material in the manner of a 3-D printer.

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