Cement premixer, a device for producing a concrete mixture and a method for producing a cement suspension

1 . A cement premixer, comprising

a treatment container having a treatment space, wherein the treatment container comprises a side wall and a bottom;

a stirring unit at least partially projecting into the treatment space, wherein the stirring unit is connected to a shaft having an axis of rotation;

at least one ultrasound probe at least partially projecting into the treatment space;

at least one ultrasonic oscillator configured to emit ultrasound to the at least one ultrasonic probe;

a first introduction opening configured to supply cement;

a solids valve coupled between the first introduction opening and a solids supply container;

a water line coupled to a second introduction opening via a water control valve;

an outlet for a flow supply line to supply an activated cement suspension from the cement premixer into a concrete mixer;

a regulating valve coupled between the outlet and the concrete mixer; and

a control and/or evaluation unit configured to generate transient cavitation in an ultrasonic field of the at least one ultrasonic oscillator in the treatment space and activate the cement in the treatment space by

adjusting the emitted ultrasound to have an intensity of 25-250 W/cm 2 and an amplitude of amplitude is 15-500 μm while controlling the stirring unit to stir the cement and water, and

causing the ultrasonic probe to transmit ultrasound in a frequency range from 18 kHz to 22 kHz, and

wherein the control and/or evaluation unit is further configured to control the solids valve, the water control valve, and the regulating valve so that the cement premixer premixes cement in a batch process.

2 . The cement premixer of claim 1 , wherein the cement premixer has a flange configured for connection to the concrete mixer.

3 . The cement premixer of claim 1 , wherein the at least one ultrasonic probe at least partially projects into the treatment space through the side wall of the treatment container.

4 . The cement premixer of claim 1 , wherein the treatment container has an axially symmetrical and rotationally symmetrical side wall, wherein an axis of symmetry of the side wall extends parallel to the axis of rotation of the stirring unit.

5 . The cement premixer of claim 4 , wherein the side wall has an extension in a half towards the bottom, wherein the extension extends around an entire circumference of the side wall concentrically to the axis of symmetry.

6 . The cement premixer of claim 5 , wherein the at least one ultrasonic probe comprises three or more ultrasonic probes projecting into the treatment space distributed at a same angle to one another about the axis of symmetry of the side wall.

7 . The cement premixer of claim 6 , wherein the three or more ultrasonic probes are arranged in a region of the extension in the side wall.

8 . The cement premixer of claim 4 , wherein the at least one ultrasonic probe has a longitudinal axis and the longitudinal axis is arranged at an angle of 55° to 65° to the axis of symmetry of the side wall of the treatment container and is aligned in a direction of the bottom of the treatment container.

9 . The cement premixer of claim 1 , wherein the cement premixer has a control and/or evaluation unit configured to control the stirring unit in such a way that operation takes place at speeds of 200 revolutions per minute to 300 revolutions per minute.

10 . The cement premixer of claim 1 , further comprising:

a level sensor configured to determine a filling level of the cement premixer.

11 . The cement premixer of claim 10 , wherein the control and/or evaluation unit is configured to control an agitation speed of the stirring unit or an energy input of the ultrasonic oscillator as a function of the determined filling level.

12 . A device for producing a concrete mix, the device comprising:

a concrete mixer;

an aggregate container coupled to the concrete mixer and configured to supply aggregate to the concrete mixer; and

a cement premixer, which the cement premixer comprises

a treatment container having a treatment space, wherein the treatment container comprises a side wall and a bottom;

a stirring unit at least partially projecting into the treatment space, wherein the stirring unit is connected to a shaft having an axis of rotation;

at least one ultrasound probe at least partially projecting into the treatment space;

at least one ultrasonic oscillator configured to emit ultrasound to the at least one ultrasonic probe;

a first introduction opening configured to supply cement; a solids valve coupled between the first introduction opening and a solids supply container;

a water line coupled to a second introduction opening via a water control valve;

an outlet for a flow supply line to supply an activated cement suspension from the cement premixer into the concrete mixer;

a regulating valve coupled between the outlet and the concrete mixer; and

a control and/or evaluation unit configured to generate transient cavitation in an ultrasonic field of the at least one ultrasonic oscillator in the treatment space and activate the cement in the treatment space by

adjusting the emitted ultrasound to have an intensity of 25-250 W/cm 3 and amplitude of 15-500 μm while controlling the stirring unit to stir the cement and water, and

causing the emitted ultrasound to transmit ultrasound in a frequency range from 18 kHz to 22 kHz, and

wherein the control and/or evaluation unit is further configured to control the solids valve, the water control valve, and the regulating valve so that the cement premixer premixes cement in a batch process, and

wherein the concrete mixer is configured to mixer premixed cement from the cement premixer supplied via the regulating valve with aggregate from the aggregate container.

13 . The device of claim 12 , wherein the cement premixer is fluidically connected to the concrete mixer by a flanged connection between the outlet of the cement premixer and an inlet of the concrete mixer.

14 . The device of claim 13 , further comprising at least one of the following:

a first cement container;

a second cement container;

a water inlet; and

an admixture container,

wherein the inlet of the concrete mixer is an inlet pipe or inlet shaft, wherein the inlet pipe or inlet shaft is detachably connected by a flange connection to at least the first cement container, the water inlet, or the admixture container.

15 . A method, comprising:

supplying cement, via a solids valve, and water, via a water control valve, into a treatment container having a treatment space;

mixing, by at least one stirring unit at least partially projecting into the treatment space, the supplied cement and water;

transmitting, by at least one ultrasonic probe at least partially projecting into the treatment space while the at least one stirring unit mixes the supplied cement and water, ultrasonic oscillations having an intensity, amplitude, and ultrasonic frequency that activates the cement in the treatment space to form an activated cement suspension and that generates transient cavitation in the treatment space, wherein the intensity is 25-250 W/cm 3 , the amplitude is 15-500 μm, and the ultrasonic frequency is in a frequency range from 18 kHz to 22 kHz;

discharging the activated cement suspension via an outlet for further processing in a concrete mixer; and

mixing, by the concrete mixer, the activated cement suspension with aggregate,

wherein the solids valve, the water control valve, and a regulating valve coupled between an outlet of the cement premixer and the concrete mixer are controlled so that the cement premixer premixes cement in a batch process.

16 . The method of claim 15 , wherein the discharging of the cement suspension is performed according to a specific energy input per unit volume of the cement suspension.

17 . The method of claim 15 , wherein, based on a total mass of the cement suspension, with all components in the cement suspension adding up to 100 parts by weight, the cement suspension is

from 20 parts by weight to 80 parts by weight cement;

from 20 parts by weight to 80 parts by weight water; and

from 0 to 10 parts by weight admixture.

18 . The method of claim 15 , wherein ultrasonic oscillations are generated by at least one ultrasonic oscillator, which applies ultrasound to the at least one ultrasonic probe.

19 . The method of claim 15 , wherein the stirring unit is operated at a speed of 200-300 revolutions per minute.