CH714991A2 - Mobile mixing device for the production of building materials from a bulk material and a liquid for construction purposes on a construction site. - Google Patents

Abstract

Mixing device (1) for producing different building materials from a bulk material. The mixing device (1) has a motor (30), a mixing unit (10) and a gas mixing unit (20). The mixing unit (10) comprises a bulk material feed (16), a liquid feed (15) and a mixing tool (11). The gas admixing unit (20) comprises a gas supply (25) and a gas blending tool. The invention also relates to building material systems comprising such a mixing device (1) and bulk materials with at least one binder and at least one gas-pore pack. According to the further disclosed method for producing different building materials from a bulk material metered gas is added to the wet material, so as to reduce the density of the bulk material-liquid mixture controlled.

Description

description

TECHNICAL FIELD The present invention relates to bulk goods as well as devices and methods for producing building materials from a bulk material.

PRIOR ART On construction sites, building materials such as e.g. Mortar, plaster, screed, concrete or plaster, often required in different densities or strengths. To achieve a certain density or strength, so-called light additives, which contain air, are added to the bulk material from which the building material is produced on site with the addition of mixing water. The air contained in the dressed building material influences its density and strength.

Construction materials are mostly required in large quantities on construction sites and the corresponding bulk material is often transported to the construction site in silos and stored on site. For the production of building materials with different strengths and densities, bulk goods with different light aggregates or light aggregate proportions are required, so that often several silos have to be transported to the construction site and stored there. This can lead to logistical, economic and ecological expenses, also because the content of individual silos is often not fully used. When changing the silo to produce building materials of different densities / strengths, it may also be necessary to dismantle and reassemble the construction mixer.

The addition of light supplements in the factory may require effort and additional equipment and affect the productivity of the factory. In addition, the production or reduction of light supplements can be ecologically problematic. In the conventional method, bulk goods also have to be transported to the construction site in large volumes, which is also logistically, economically and ecologically problematic. There is work involved on site because large volumes of material have to be introduced into the construction mixer. In addition, there is a risk that the lightweight aggregates will be mechanically destroyed during filling, conveying, transport or preparation and thus lose their effectiveness.

Mixing devices, such as e.g. Plastering machines or concrete mixers for making building materials on site are known in principle.

DE 20 2016 004 782 describes, for example, a mixing vessel with a stirrer for mixing mortar, the stirrer being a vertical drive shaft with stirring elements, such as e.g. a worm thread.

SUMMARY OF THE INVENTION It is an object of the invention to overcome disadvantages of the prior art. Particularly preferred are an improved mixing device for the production of building materials, a construction machine and a building material system, each of which has such an improved mixing device, an improved bulk material and an improved method for the production of building materials.

The invention solves this problem with the features of the independent claims. Further embodiments are specified in the dependent claims.

The mixing device according to the invention for the production of building materials for construction purposes mixes a starting raw material, namely bulk material, with liquid, normally water, so that a viscous mixture of bulk material and liquid, also called wet material, is produced. This manufacturing process is also referred to as mixing and the water used for mixing. The mixing device according to the invention comprises

- a mixing unit for mixing a bulk material with a liquid, and

- A gas admixing unit for admixing a gas to a bulk material-liquid mixture.

The bulk material can have binders, aggregate and additives. The bulk material can be suitable for this with liquid, e.g. Water to be mixed into a wet building material that hardens when it dries out. Bulk goods can be dry and consist of granular mixtures. The wet material can be used as building material and e.g. apply or be sprayed on.

Suitable bulk solids in the sense of the present invention are bulk solids in which hydraulic or non-hydraulic binders are contained. Both hydraulic and non-hydraulic binders which are used in building materials are known to the person skilled in the art.

The hydraulic binder can be selected from cement, hydraulic lime or hydrated lime and from combinations of the aforementioned binders. The bulk material preferably contains at least one hydraulic binder, in particular in the form of cement, and possibly one or more further hydraulic binders.

In a preferred embodiment of the present invention, the bulk material contains the hydraulic binder in a proportion of up to 65 wt .-%, based on the total weight of the bulk material. In the context of the present invention, proportions of hydraulic binder of 7 to 25% by weight are preferred, furthermore a proportion of hydraulic binder of 10 to 20% by weight is preferred. In the event that the bulk material has at least one hydraulic binder

Contains CH 714 991 A2 in the form of cement and one or more further hydraulic binders, the weight-based proportion of cement is preferably higher than the weight-based proportion of the further hydraulic means (s).

In the case in which the bulk material is a bulk material in which a hydraulic binder is used as a binder, the proportion of aggregate is preferably 10 to 90% by weight, furthermore a proportion of aggregate of 10 up to 45% by weight is preferred.

The non-hydraulic binder can be selected from gypsum such as stucco or α-hemihydrate, hydraulic lime or hydrated lime and from combinations of the aforementioned binders. The bulk material preferably contains at least one non-hydraulic binder, in particular in the form of gypsum, and possibly one or more further non-hydraulic binders.

In a preferred embodiment of the present invention, the bulk material contains the non-hydraulic binder in a proportion of up to 95% by weight, based on the total weight of the bulk material. In the context of the present invention, proportions of non-hydraulic binder from 20 to 85% by weight are preferred, furthermore a proportion of hydraulic binder from 60 to 85% by weight is preferred. In the event that the bulk material contains at least one non-hydraulic binder in the form of gypsum and one or more further hydraulic binders, the weight-based proportion of gypsum is preferably higher than the weight-based proportion of the further hydraulic agent (s).

In the case in which the bulk material is a bulk material in which a non-hydraulic binder is used as the binder, the proportion of aggregate is preferably 3 to 20% by weight, with a further proportion of aggregate of 5 to 10% by weight is preferred.

The aggregate contains natural or artificial mineral aggregates. Suitable mineral aggregates are sands and stone flours of various origins and their mixtures, but in particular quartz sand and limestone powder. For example, the aggregate can comprise a mixture of quartz sand and limestone powder.

[0019] In a preferred embodiment of the present invention, the bulk material contains up to a proportion of 95% by weight of aggregate.

[0020] In a preferred embodiment of the present invention, the bulk material can have the following composition:

cement 7-35 Wt .-% hydrated lime 0-10 Wt .-% Natural hydraulic lime 0-20 Wt .-% quartz sand 0-90 Wt .-% limestone 0-10 Wt .-% Limestone crushed sand 0-90 Wt .-% Stärkeaether 0-0.3 Wt .-% Celluloseaether 0.05-0.2 Wt .-% Amphoteric surfactants 0.05-0.9 Wt .-% clay minerals 0-2 Wt .-% alginates 0.0-0.5 Wt .-%

[0021] A recipe example for this is:

Cement I 42.5 14 Wt .-% Hydrated lime CL90 J Wt .-% Natural hydraulic lime (NHL) 2 Wt .-% Quartz sand 0.1-0.5mm 20 Wt .-% limestone 14 Wt .-% Limestone crushed sand 0.5-1.0 40 Wt .-%

CH 714 991 A2

Celluloseaether

0.13

Wt .-%

Amphoteric surfactants 0.07% by weight

Kaolin 1.6% by weight

alginates

0.1% by weight In a preferred embodiment of the present invention, the bulk material can have the following composition:

plaster 20-95 Wt .-% hydrated lime 0-10 Wt .-% Natural hydraulic lime 0-20 Wt .-% quartz sand 0-30 Wt .-% limestone 0-10 Wt .-% Limestone crushed sand 0-70 Wt .-% Stärkeaether 0-0.5 Wt .-% Celluloseaether 0.10 to 0.5 Wt .-% Amphoteric surfactants 0.05-0.9 Wt .-% clay minerals 0-2 Wt .-% alginates 0-0.8 Wt .-% setting regulator 0.01-1 Wt .-%

[0023] A recipe example for this is:

Stucco 60% by weight

Alpha hemihydrate 10% by weight

Lime hydrate CL90 3% by weight

Natural hydraulic lime (NHL) 10

Wt .-%

Quartz sand 0.1-0.5mm

Wt .-%

Limestone flour 5% by weight

Limestone crushed sand 0.5-1.0 5% by weight

Cellulose ether 0.24% by weight

Amphoteric surfactants 0.2% by weight

kaolin

2.9

Wt .-%

Alginates 0.16% by weight

setting regulator

0.5% by weight The bulk material can generally contain further constituents in the form of additives or additives, in particular the bulk material can contain water retention agents such as cellulose ether, fillers such as crushed limestone sand, adjusting agents such as starch ether, setting regulator and possibly other additives known to the person skilled in the art contain.

In a preferred embodiment of the present invention, the bulk material further comprises a gas-pore packing, wherein said gas-pore packing, when gas is added to the wet material, forms and proceeds

CH 714 991 A2, the gas pores formed were relieved. The gas-pore packing comprises at least one air-entraining agent or one air-entraining agent, preferably both air-entraining agents and air-entraining agents being used.

Suitable air entraining agents are, for example, surfactants, in particular amphoteric surfactants, the air entraining agents preferably occurring in a proportion of up to 2% by weight, more preferably in a proportion of 0.05 to 1% by weight, based on the total weight of the bulk goods.

Suitable air pore stabilizers are, for example, organic or mineral air pore stabilizers, such as clay minerals and alginates, the organic and mineral air pore stabilizers preferably being used as a mixture. The air pore stabilizers are preferably contained in a proportion of up to 5% by weight, more preferably in a proportion of 1.5 to 3% by weight, based on the total weight of the bulk material.

[0028] The bulk material is preferably low-aggregate and comprises, for example, less than 10% by weight, preferably less than 5% by weight, lightweight aggregate. The bulk material is preferably free of light surcharges and essentially does not include any light surcharges. Light aggregates can be, for example, substances with a bulk density between 12 kg / m ³ , such as expanding polystyrene, and 800 kg / m ³ , such as expanded clay. Frequently used light aggregates are pumice, foam lava, perlite, styrofoam, expanded glass, expanded clay, expanded slate and boiler sand.

To simplify the invention, the invention will now be described below by way of example for mortar; however, this is purely exemplary and the invention also relates to other suitable building materials, such as Plaster, screed, concrete and plaster. For example, the mixing device according to the invention can be set up to produce mortar and can comprise a mixing unit for mixing wet mortar from dry mortar and mixing water and a gas admixing unit for mixing ambient air into the wet mortar.

The mixing machine is preferably set up for the in-situ production of building materials on a construction site.

[0031] The mixing device can be mobile. Mobile can mean that the mixing device is designed as a hand-held, or mobile and / or transportable device. The mixing device can in particular be designed to be portable.

[0032] The mixing unit can have a motor, which can be designed, for example, as a diesel or as an electric motor.

The mixing unit can be a bulk feed for bulk feed, such as e.g. a hopper or a connection to a silo. The mixing unit can be a liquid supply, e.g. have an opening with a connected hose for the supply of liquid. The mixing unit can be a mixing tool, e.g. a cross bar stirrer for mixing a bulk material-liquid mixture.

The gas admixing unit can be a gas supply for supplying gas, e.g. an opening with a valve. The gas admixing unit can be a gas admixing tool, e.g. have a screw pump for admixing gas.

The bulk material-liquid mixture or the bulk material-liquid mixture with added gas is also simply called wet material.

The admixing of gas to the wet material creates a building material with an increased gas content, e.g. increased gas-pore content, and thus reduced density. With this, e.g. in-situ, building material with the desired density or properties related to the density, e.g. Strength or thermal conductivity. In particular, it may be possible to produce building materials with different requirements, such as density, strength and / or thermal conductivity, from the same bulk material on site at the construction site.

The mixing device can be set up to meter the amount of gas mixed into the wet material. The mixing device can have a gas supply regulation for metering the amount of the gas mixed into the wet material. The gas supply regulation can be arranged on the gas admixing unit, in particular on one or more gas supply openings. The gas supply regulation can be set up for stepless metering and / or for stepping metering of the admixture of gas. The gas supply regulation can have one or more valves, in particular regulating valves and / or valves for step regulation as are described further below. In particular, the gas supply regulation can have one or more switches, that is to say a valve with essentially two opening states (open / closed). Switches are particularly suitable for use on a construction site because they can be designed to be stable and easy to use.

By metering the amount of gas which is mixed per unit volume and / or per unit mass of wet or bulk material, the gas content in the building material can be controlled. This makes it possible to manufacture building material with a specific requirement, especially in-situ.

The use of the mixing device presented will only allow bulk materials of the same type, e.g. Only one type of mortar has to be stored, since the same bulk material can be processed in-situ into wet material with different requirements using the mixing tool. This only bulk material to be stored is preferably a bulk material which is free of light aggregates or at least low in bulk aggregates. By using the mixing device presented, the efficiency of the bulk material factories can be increased, transport and storage costs can be minimized and

CH 714 991 A2 the environment. The bulk material used can be purely mineral and e.g. no longer contain styrofoam. The building material produced in this way can be used on all mineral substrates.

The mixing tool preferably comprises a rotating stirring device. The stirring device can be mounted on a shaft. The shaft can be driven by the motor. The stirring device can have a cross bar stirrer. The stirring device can comprise stirring blades which can be arranged perpendicular to a shaft. The stirring device can have a stirring helix.

The mixing device preferably has a pump. In particular, the gas admixing unit can have a pump. The pump can be designed, for example, as a screw pump and / or as a piston pump.

[0042] The mixing device can have a conveying device, for example for conveying the wet material. The conveyor device can comprise a pump.

The pump can be set up to suck or push liquid into the mixing unit. The pump can be set up to suck or push gas into the gas admixing unit. The pump can be set up to suck or push wet material from the mixing unit into the gas admixing unit. The pump can be set up to suck or push wet material out of the gas admixing unit. The pump can be set up to push wet material through an outlet. The mixing tool can be designed as a pump. The gas admixing tool can be designed as a pump.

[0044] The gas admixing tool preferably comprises a rotating stirring device and / or a rotating pump device. For example, the gas admixing tool can have a screw pump, which can function both as a stirring device and as a pump device. The screw pump can be designed to move the wet material in the mixing device and at the same time to add gas to the wet material. A pump comprised by the gas admixing tool can also be set up to generate a negative pressure which enables the gas supply to suck in gas.

A worm pump, also called Archimedean screw or screw pump, has a rotor and a stator, the rotor stirring elements, e.g. in the form of a helix or a double helix. For example, the rotor can be designed as a steel shaft. The stator can be designed, for example, as an elastic rubber housing. The geometry of the screw influences the throughput and the pressure of the screw pump. The screw pump can be connected to the motor directly or indirectly, that is to say force-acting, and can be driven by it.

[0046] Optionally, the gas admixing tool can be designed as a screw pump and can be set up to

- to move the wet material in the mixing device,

- add gas to the wet material, and

- Suck gas through one, two or more gas supply openings in the stator.

[0047] The mixing device, in particular the gas supply, can be set up to draw in ambient air. The ambient air can be mixed into the wet material for density reduction. Ambient air is particularly suitable as a mixed gas because it is available everywhere and free of charge.

The gas supply can have at least one gas supply opening, in particular two or more gas supply openings. The gas feed opening can be arranged on the gas admixing unit, in particular on a housing of the gas admixing unit. For example, the gas supply opening can be formed in the stator, in particular an elastic stator, of a screw pump of the gas admixing unit. The gas supply opening can be designed as a channel, for example as a channel in an elastic stator of a screw pump. The gas supply opening can have a diameter of 0.5 mm-3 mm, in particular of 1 mm-2.5 mm, for example from 1.4 mm to 2.1 mm.

The gas supply can be operated with negative pressure, e.g. with a vacuum generated by a pump. For example, a gas supply opening can be formed in the stator of a screw pump of the gas admixing unit, so that gas is sucked through the gas supply opening by a negative pressure generated by the screw pump. The gas sucked in in this way can be mixed into the wet material in the gas admixing unit by stirring the screw pump, so that the action of the screw pump both supplies and mixes the gas.

The gas supply can be operated with compressed air, for example with a pressure between 1 bar and 60 bar, preferably with a pressure between 2 bar and 40 bar, particularly preferably with a pressure between 4 bar and 12 bar. For this purpose a source of compressed air, e.g. a compressed air bottle, a compressed air feeder (e.g. a compressor) or a compressed air network can be connected to the mixing device.

The gas supply can e.g. at a gas supply opening, have a valve. The valve can be set up for metering the admixture of gas to the wet material. The valve can in particular be set up to regulate the open position of one or more gas supply openings. The valve can be part of a gas supply regulation.

The valve can be designed as a control valve, ie as a continuous valve. In other words, the valve can be set up to enable a continuous, that is to say continuous, regulation of its open positions. The control valve can in particular have a rotary control, which is set up so that the open position of the valve can be regulated continuously by means of a rotation.

CH 714 991 A2 The gas supply can be designed for continuously metering the supply of gas. The gas supply can have a control valve for the constant metering of the supply of gas. For example, a control valve that controls the inflow to a gas supply opening can be set up for continuously metering the supply of gas through the gas supply opening.

The valve can be set up to regulate its open position in stages. In other words, the valve can be set up to assume only a discrete, in particular a finite, number of different open positions.

The gas supply can be designed for the gradual metering of the supply of gas. The gas supply can have a valve for the gradual metering of the supply of gas. For example, a valve that controls the inflow to a gas supply opening can be set up for stepwise metering of the supply of gas through the gas supply opening.

The valve can be designed as a switch, ie as a valve with essentially two opening states (open / closed).

The valve can be designed as a check valve or contain a check valve. The check valve can be arranged in such a way that it prevents wet goods from escaping from the mixing device through the gas supply. The gas supply preferably has at least two gas supply openings, in particular exactly two gas supply openings. Each of the gas supply ports may have a valve. The valves can in particular be set up to individually regulate the supply of gas to each of the gas supply openings.

Two gas supply openings, each provided with a switch, can allow up to four different stages of the supply of gas via the respective open / closed position of the switches. If both gas supply openings can supply the same amount of gas when open, three different stages of supplying gas are possible, namely:

- Both gas supply openings are closed, so that no gas is supplied;

- exactly one of the gas supply openings is opened, so that the simple amount of gas is supplied; and

- Both gas supply openings are open so that twice the amount of gas is supplied.

[0060] For example, the mixing device can be designed such that, for a specific bulk material, the strength of the dried discharge

- Without gas supply, ie when both gas supply openings are closed, approx. 6 N / mm ² ;

- With a simple gas supply, i.e. if exactly one gas supply opening is open, approx. 4 N / mm ² and

- With double gas supply, i.e. when both gas supply openings are open, is approximately 2 N / mm ² . The values can vary, for example, by ± 10%.

[0061] The mixing tool and the gas admixing tool can be mechanically coupled to one another. For example, one of the two tools can be driven by the motor and drive the other tool through the mechanical coupling. The mixing tool and the gas admixing tool can each be rotatably supported on a shaft and the two shafts, e.g. be mechanically coupled to one another by a notch. The mechanical coupling can have a gear. The mixing tool and the gas admixing tool can also be mounted on a common shaft.

[0062] The gas admixing unit can be arranged downstream of the mixing unit with respect to the direction of flow of the wet material in the mixing device. The mixing device can be designed such that the mixing device moves wet material from the mixing unit into the gas admixing unit.

The mixing unit and the gas admixing unit are preferably arranged in a common housing.

[0064] The mixing unit and the gas admixing unit can be designed as a common unit. For example, the mixing tool and the gas mixing tool can be used as the only tool, e.g. be designed as a single screw pump.

[0065] The mixing device can have an outlet for discharging wet material. In particular, the outlet can be set up to discharge the bulk material-liquid mixture produced by the mixing device with admixed gas. The outlet can be downstream of the gas admixing unit with respect to the direction of flow of the wet material in the mixing device.

The mixing device can be set up to discharge wet material with pressure, for example with a pressure of 4 bar to 20 bar, preferably with a pressure of 6 bar to 12 bar. The outlet can in particular have a spraying device with which the wet material can be sprayed on. The pressure can e.g. be generated by a pump, in particular by a gas admixing tool designed as a screw pump. The mixing device can have a device for regulating the outlet pressure.

In some embodiments, the mixing device is mobile and suitable for the in-situ production of building materials from a bulk material and a liquid for construction purposes on a construction site, and has a motor and a mixing unit for mixing a bulk material with a liquid, the mixing unit comprises a bulk material feed for bulk material supply, a liquid supply for liquid supply and a mixing tool for mixing a bulk liquid-liquid mixture, wherein the mixing device further comprises a gas admixing unit for mixing a gas into the bulk liquid-liquid mixture, wherein the Gas admixing unit a gas supply for supplying gas and a

CH 714 991 A2

Gas admixing tool for admixing gas, wherein the gas admixing tool comprises a screw pump and the gas supply has at least two gas supply openings arranged in the stator of the screw pump. The described mixing device can be arranged in a construction machine, in particular in a mobile working device. The construction machine can be a plastering machine, for example.

The mixing device described can be arranged together with a storage unit for storing a bulk material and a water tank and / or a water pipe in a building material system. The mixing device can in particular be arranged in a construction machine which is arranged in the building material system. The storage unit can be designed as a silo, as is typically used on construction sites. The storage unit can be connected to the bulk material feed so that bulk material can reach the mixing device from the storage unit. In particular, the building material system can have a device to control the amount of bulk material delivered to the mixing device. The water tank and / or the water pipe can be connected to the liquid supply so that water from the water tank and / or the water pipe can get into the mixing device. In particular, the building material system can have a device for controlling the amount of water delivered to the mixing device. The gas supply can be set up to draw in ambient air. Alternatively or additionally, the gas supply can be connected to a compressed air supply.

The invention further relates to a method for producing building materials from a bulk material, such as e.g. Dry mortar, whereby the bulk material is mixed with liquid, e.g. Mixing water, is mixed and the resulting bulk material-liquid mixture doses gas in-situ, e.g. Ambient air is mixed. The metered addition of gas enables the density of the bulk material-liquid mixture, e.g. To reduce wet mortar. In particular, the density of the building material to be produced can be controlled by metering the amount of the admixed gas per unit volume and / or per unit mass of wet or bulk material. This makes it possible to produce building materials with different properties, such as density, strength and / or thermal conductivity, from the same bulk material, in particular in situ.

The method relates in particular to the in-situ production of building materials. In-situ can mean producing the building material on a construction site, in particular outside a factory.

The method relates in particular to the production of building materials free of slight additions. Light-aggregate-free production can mean that no light aggregate is added to the bulk material in the method and / or that the bulk material does not contain any light aggregate.

The method is preferably carried out using one of the mixing machines presented.

The method or the mixing device can be used to produce two or more wet goods of different densities from the same bulk material by adding different amounts of gas. As a result, the respective building materials can have a different density, strength and / or thermal conductivity, which is individually adapted to the purpose. In particular, the method or the mixing device can be used to include a building material from a bulk material that is free from low-aggregate or low-aggregate, for example less than 50% by weight, preferably less than 20% by weight, of lightweight aggregate

low density, such as less than 1500 kg / m ³ , in particular less than 1000 kg / m ³ ,

- low strength, such as less than 4 N mm ^-2 , in particular less than 2.5 ° N ° mm ^_2 , and / or

- Low thermal conductivity, such as less than 0.5 W m ^_1 K ^_1 , in particular less than 0.3 W m ^_1 K ^_1 to produce.

The method and the mixing device can be used to lightweight concrete from bulk for normal or. To produce heavy concrete. One speaks of lightweight concrete in concretes with a dry bulk density of up to 2000 kg / m ³ , in particular between 800 and 2000 kg / m ³ , of normal or heavy concrete one speaks in concrete with a dry bulk density of over 2000 kg / m ³ , in particular of over 2050 kg / m ³ .

The method and the mixing device can be used to light mortar from bulk material for normal or. To produce heavy mortar. One speaks of light mortar for mortars with a dry bulk density of up to 1500 kg / m ³ , in particular between 800 and 1500 kg / m ³ , of normal or heavy mortar one speaks for mortars with a dry bulk density of over 1500 kg / m ³ , in particular of over 1550 kg / m ³ .

The method can, in particular using the described mixing device, be carried out in such a way that the building material produced has a dry density which is at least 10%, in particular at least 40%, lower than the bulk material.

The method can, in particular using the described mixing device, be carried out in such a way that a first and a second building material are produced from a bulk material and the first building material produced has a dry density which is at least 10%, in particular at least 20%, lower than the second building material produced.

The method can, in particular using the described mixing device, preferably be carried out in such a way that a first and a second wet material are produced from a bulk material and the first one produced

CH 714 991 A2

Wet material has a density that is at least 10%, in particular at least 20%, lower than the second wet material produced.

In some variants of the method, a building material is produced from one of the bulk materials presented in-situ and using a mobile mixing device for in-situ production of building materials from a bulk material and a liquid for construction purposes on a building site, the mixing device being a motor and a mixing unit for mixing a bulk material with a liquid, the mixing unit having a bulk material supply for supplying. Bulk material, a liquid supply for supplying liquid and a mixing tool for mixing a bulk material-liquid mixture, and the mixing device further comprises a gas admixing unit for admixing a gas to the bulk material-liquid mixture, the gas admixing unit comprising a gas Includes supply for supplying gas and a gas admixing tool for admixing gas, and wherein the bulk material is mixed with liquid in the mobile mixing device and gas is metered into the bulk material-liquid mixture in the mobile mixing device so as to increase the density of the bulk material. Reduce liquid mixture.

In the method, a requirement for the building material to be produced is preferably specified and the metering of the admixed gas is selected in accordance with the specified requirement. The requirement can be, for example, a requirement for a density, strength and / or thermal conductivity of the building material to be produced. With the metering of the gas, the metering of the amount, i.e. e.g. Volume and / or mass of the mixed gas per unit, e.g. per volume unit and / or per mass unit, wet goods or bulk goods. By metering the admixed gas, the gas content in the building material and thereby a variety of properties of the building material, such as its density, strength and / or thermal conductivity, can be controlled. In the method, a mobile mixing device with a gas supply regulation can be used and the gas supply regulation, preferably valves of at least two gas supply openings arranged in the stator of the screw pump, can be adjusted according to the specified requirement.

In the method, a first and a second building material are preferably produced from the same bulk material, the first and the second building material differing in their respective density, strength and / or thermal conductivity, and a first is used to produce the first building material Gas metering and a second gas metering used to produce the second building material, the first and the second gas metering differing from one another. In other words, less or more gas is added to the wet material in one case than in the other case. If, for example, the second building material is to be less dense, firm and / or thermally conductive than the first building material, the second building material can be produced with a higher gas dosage than the first building material, so that more gas is added to the second building material. The first building material is preferably such that the density of the hardened mass is more than 800 kg / m ³ , and the second building material is such that the density of the hardened mass is less than 600 kg / m ³ . A building material, the hardened mass of which has a density of less than 600 kg / m ³ , can have improved sound absorption properties.

In a further process step, the wet material mixed with gas can be applied in terms of construction.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described below with reference to the drawings, which are used only for the purpose of explanation and are not to be interpreted as restrictive. The drawings show schematically:

1 shows a mixing device; and

Fig. 2 is a screw pump.

DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows a mixing device 1 with a mixing unit 10 and a gas admixing unit 20. The mixing device 1 furthermore has a motor 30, a bulk material feed 16 in the form of a funnel, a liquid feed 15 and one Gas supply 25 on.

The bulk material feed 16 and the liquid feed 15 are arranged on the mixing unit 10 in such a way that bulk material and liquid supplied can be mixed with one another to form a wet material by the mixing tool 11 arranged in the mixing unit 10. The liquid supply 15 is connected via a hose to a liquid source (not shown), for example a water tank or a water line connection. In the example shown, the mixing tool 11 is designed as a cross-bar stirrer mounted on a shaft 12 with stirring elements 13 arranged perpendicular to the shaft. The stirring element 13 can, for example, also be designed as a stirring spiral.

The gas admixing unit 20 is located downstream of the mixing unit 10, so that wet material is transported from the mixing unit 10 into the gas admixing unit 20. The gas admixing tool 21 arranged in the gas admixing unit 20 is designed as a screw pump 61, that is to say as an Archimedean screw. The screw pump 61 comprises helix-shaped stirring elements 23 mounted on a shaft 22 and acts as a pump 60, so that it sucks the wet material from the mixing unit 10 into the gas admixing unit 20. There are one or two gas supply openings 26a, 26b on the gas admixing unit 20

CH 714 991 A2 transmit, gas supply 25 arranged. The gas supply openings 26a, 26b are arranged in the stator 62 of the screw pump 61 and are each provided with a valve 27a, 27b (shown symbolically). When the first valve 27a is open, gas, preferably ambient air, is drawn in by the screw pump 61 and mixed with the wet material by its stirring movement. The wet material is thereby enriched with gas, which lowers the density and modifies other properties of the building material, such as strength and / or thermal conductivity. By opening the second valve 27b, even more gas can be drawn in and the density of the wet material can be reduced even further. The two valves 27a, 27b can act as a gas supply regulator 29 and allow the amount of gas mixed into the wet material to be metered. The two valves 27a, 27b can be designed as control valves, and thus enable a continuous fine adjustment of the gas content in the wet material. In alternative exemplary embodiments, the gas is supplied to the gas admixing unit 20 by means of and / or as compressed air (not shown).

In the example shown, the mixing unit 10 and the gas admixing unit 20 are arranged in a common housing 2. The mixing tool 11 and the gas admixing tool 21 are both designed as rotating tools and are each mounted on a shaft 12, 22. The motor 40 is arranged at one end of the housing 2 and drives the shaft 12 of the mixing tool 11. The shaft 12 of the mixing tool 11 is mechanically coupled to the shaft 22 of the mixing tool 21 so that it drives it. This mechanical coupling can take place, for example, by means of a notch with a wing engaging therein or a gear (neither of which is shown). At the other end of the housing 2, the outlet 40 is arranged, through which the wet material, possibly mixed with gas, can be discharged. The outlet 40 can be connected to a spray device (not shown), for example, so that the wet material can be sprayed out under the pressure generated by the pump 60. As a result, the mixing device 10 may be suitable for the adhesive spray ejection technique and e.g. can be used in a plastering machine.

2 shows a screw pump 61 with a rotor 63 and a stator 62 surrounding it. The stirring element 23 of the rotor 63 is designed as a helical steel shaft and the stator 62 as an elastic rubber housing. As known from the principle of the Archimedean screw, chambers 64 are formed when rotating between the stator 62 and the rotor 63, through which material is transported from one end of the screw to the other end of the screw. As a result of the rotation, the material located in the chambers 64 is whirled through in interaction with gravitation. If a chamber 64 has wet and gas, e.g. Gas pores are enclosed in the wet material, thus reducing the density of the wet material.

In the example shown, the dimensionally stable rotor 63 rotates in the elastic stator 62 such that the chambers 64 are, at least essentially, gas-tight. This creates a negative pressure at the beginning of the screw and an overpressure at the end of the screw, so that the screw can act as a pump. Such a screw pump 61 can function both as a stirring device and as a pump in the mixing device and e.g. can be used as a gas admixing tool.

The stator 62 can have openings designed as gas supply openings (not shown). The screw can suck gas, such as ambient air or other gas directed to the openings, into the chambers 64 through the openings. The openings can have a diameter of 1 mm to 2.5 mm, for example.

The following aspects are proposed:

Aspect 1: A mobile mixing device 1 for the in-situ production of building materials from a bulk material and a liquid for construction purposes on a construction site, comprising a motor 30 and a mixing unit 10 for mixing a bulk material with a liquid, the mixing unit 10

a bulk material feed 16 for feeding bulk material,

- A liquid supply 15 for supplying liquid and

comprises a mixing tool 11 for mixing a bulk material-liquid mixture, characterized in that the mixing device 1 has a gas admixing unit 20 for admixing a gas to the bulk material-liquid mixture, the gas admixing unit 20

a gas supply 25 for supplying gas and

a gas admixing tool 21 for admixing gas.

Aspect 2: A mobile mixing device 1 according to the above aspect, characterized in that the mixing device 1, in particular the gas admixing unit 20, has a pump 60.

Aspect 3: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas admixing tool 21 comprises a rotating stirring and / or pumping device, in particular a screw pump 61.

CH 714 991 A2

Aspect 4: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas is ambient air and the mixing device 1, in particular the gas supply 25, is set up to draw in ambient air. Aspect 5: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas supply 25 has at least one gas supply opening 26a, 26b, in particular at least two gas supply openings 26a, 26b. Aspect 6: A mobile mixing device 1 according to the above aspect, characterized in that each of the at least one gas supply openings 26a, 26b has a valve 27a, 27b, in particular wherein the valve 27a, 27b is set up to supply gas through the respective gas -Adjust opening 26a, 26b. Aspect 7: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas supply 25 is designed for the stepless regulation of the supply of gas, in particular wherein the gas supply 25 has a control valve for the constant regulation of the supply of gas. Aspect 8: A mobile mixing device 1 according to one of the aspects 1 to 6, characterized in that the gas supply 25 is designed for the step-wise regulation of the supply of gas, in particular wherein the gas supply 25 has a valve for the step-wise regulation of the supply of gas. Aspect 9: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the mixing device 1 has a gas supply regulation 29 for metering the admixture of gas, in particular wherein the gas supply regulation 29 has at least one valve 27a, 27b. Aspect 10: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas supply 25 is set up to be operated with negative pressure. Aspect 11: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas supply 25 is set up to be operated with compressed air. Aspect 12: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the mixing tool 11 and the gas admixing tool 21 are mechanically coupled to one another, in particular wherein one of the two is driven by the motor 30 and drives the other via the mechanical coupling. Aspect 13: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the gas admixing unit 20 is arranged downstream of the mixing unit 10 with respect to the direction of flow of the wet material, that is to say the bulk material / liquid mixture or the bulk material / liquid mixture with added gas. Aspect 14: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the mixing unit 10 and the gas admixing unit 20 are arranged in a common housing 2. Aspect 15: A mobile mixing device 1 according to one of the preceding aspects, characterized in that the mixing device 1 has an outlet 40 for the discharge, in particular for discharge under pressure, of wet material, in particular wherein the outlet 40 of the gas admixing unit 20 with respect to the flow direction of the wet material in the Mixing device 1 is downstream. Aspect 16: A construction machine, in particular a plastering machine, having a mobile mixing device 1 according to one of the aspects 1 to 15. Aspect 17: Having a building material system a storage unit, in particular a silo, for storing bulk goods, a mobile mixing device 1 according to one of the aspects 1 to 15, - a water tank and / or a water pipe, in which - The storage unit to the bulk feed 16 and - The water tank and / or the water pipe is connected to the liquid supply 15, and

CH 714 991 A2

- The gas supply 25 is set up to suck in ambient air and / or is connected to a compressed air supply.

Aspect 18: A method for the in-situ production of building materials from a bulk material, preferably using a mobile mixing device 1 according to one of the aspects 1 to 15, the bulk material being mixed with liquid, characterized in that the bulk material-liquid mixture in -situ metered gas is added to reduce the density of the bulk liquid-liquid mixture.

Aspect 19: A method according to aspect 18, characterized in that

- a requirement for the building material to be manufactured, in particular a requirement for a density, strength and / or thermal conductivity of the building material to be manufactured, is specified; and

- The metering of the admixed gas is selected according to the specified requirement.

Aspect 20: A method according to aspect 19, characterized in that

a mobile mixing device 1 with a gas supply regulation 29 is used for the method; and

- The gas supply regulation 29 is set according to the specified requirement.

Aspect 21: A method according to one of the aspects 18 to 20, characterized in that

- a first and a second building material are produced from the same bulk material;

- The first and the second building material differ from each other in their respective density, strength and / or thermal conductivity;

a first gas metering is used to produce the first building material and a second gas metering is used to produce the second building material; and

- The first and the second gas metering differ from each other.

REFERENCE SIGN LIST [0093]

mixing device

casing

mixing unit

mixing tool

wave

stirrer

Liquid supply

Bulk supply

Gas mixing unit

Gas Zumischwerkzeug

wave

Stirrer / Helix

Gas supply

26a gas supply opening

26b gas supply opening

27a valve

CH 714 991 A2

27b valve

Gas supply regulation

engine

outlet

pump

screw pump

stator

rotor

chamber

Claims (11)

claims 1. Mobile mixing device (1) for the in-situ production of building materials from a bulk material and a liquid for construction purposes on a construction site, comprising a motor (30) and a mixing unit (10) for mixing a bulk material with a liquid, the mixing unit ( 10) - a bulk material feed (16) for feeding bulk material, - A liquid supply (15) for supplying liquid and comprises a mixing tool (11) for mixing a bulk material-liquid mixture, the mixing device (1) having a gas admixing unit (20) for admixing a gas to the bulk material-liquid mixture, the gas admixing unit (20) - A gas supply (25) for supplying gas and - A gas admixing tool (21) for admixing gas, the gas admixing tool (21) comprising a screw pump (61) and the gas supply (25) at least two in the stator (62) of the screw pump (61) arranged gas supply openings (26a, 26b). 2. Mobile mixing device (1) according to claim 1, characterized in that each of the at least two gas supply openings (26a, 26b) has a valve (27a, 27b), which is preferably set up to supply gas through the respective Regulate gas supply opening (26a, 26b). 3. Mobile mixing device (1) according to claim 2, characterized in that the valves (27a, 27b) are designed for the staged regulation of the supply of gas, preferably as a switch. 4. Having building material system a storage unit, in particular a silo, for storing bulk goods, a mobile mixing device (1) according to one of claims 1 to 4, - A water tank and / or a water pipe, wherein - The storage unit to the bulk material feed (16) and - The water tank and / or the water pipe is connected to the liquid supply (15), and - The gas supply (25) is set up to suck in ambient air. 5. Bulk material for producing a building material, comprising at least one binder and at least one gas-pore packing, the gas-pore packing comprising at least one air-entraining agent, preferably the at least one air-entraining agent in a proportion of up to 2% by weight. , more preferably in a proportion of 0.05 to 1% by weight, based on the total weight of the bulk material, the air entraining agent preferably being an amphoteric surfactant. 6. bulk material for producing a building material, according to claim 5, wherein the gas-pore packing further comprises at least one air-pore stabilizer, preferably the at least one air-pore stabilizer in a proportion of up to 5% by weight, more preferably in a proportion of 1, 5 to 3 wt .-% is included, based on the total weight of the bulk material. 7. Bulk material for producing a building material, according to claim 5 or 6, wherein the bulk material is essentially free of light additives. 8. A method for the in-situ production of building materials from a bulk material according to one of claims 5 to 7 using a mobile mixing device (1) for the in-situ production of building materials from a bulk material and a liquid for construction purposes on a construction site, comprising a motor (30) and a mixing unit (10) for mixing a bulk material with a liquid, the mixing unit (10) CH 714 991 A2 - a bulk material feed (16) for feeding bulk material, - A liquid supply (15) for supplying liquid and comprises a mixing tool (11) for mixing a bulk material-liquid mixture, the mixing device (1) having a gas admixing unit (20) for admixing a gas to the bulk material-liquid mixture, the gas admixing unit (20) - A gas supply (25) for supplying gas and - A gas admixing tool (21) for admixing gas, preferably according to one of claims 1 to 3, wherein the bulk material in the mobile mixing device (1) is mixed with liquid and the bulk material-liquid mixture in the mobile mixing device (1 ) metered gas is added to reduce the density of the bulk liquid-liquid mixture. 9. The method according to claim 8, characterized in that - A requirement for the building material to be manufactured, preferably a requirement for a density, strength and / or thermal conductivity of the building material to be manufactured, is specified; and - The metering of the admixed gas is selected according to the specified requirement. 10. The method according to claim 9, characterized in that - A mobile mixing device (1) according to one of claims 2 or 3 is used for the method; and - The valves (27a, 27b) of the at least two gas supply openings (26a, 26b) arranged in the stator (62) of the screw pump (61) are adjusted according to the specified requirement. 11. The method according to any one of claims 8 to 10, characterized in that - A first and a second building material are made from the same bulk material; - The first and the second building material differ from each other in their respective density, strength and / or thermal conductivity; a first gas metering is used to produce the first building material and a second gas metering is used to produce the second building material; and - The first and the second gas metering differ from each other. CH 714 991 A2

20,60,61 CH 714 991 A2