US-20260124786-A1 - Mixer

US20260124786A1US 20260124786 A1US20260124786 A1US 20260124786A1US-20260124786-A1

Abstract

A mixer and a method for the mixing of a cementitious slurry, configured to calculate the volume of the cementitious slurry in the mixer in order to produce an improved mixing process and/or an improved cementitious product. The mixer comprises a sensor to measure a parameter of the slurry in the mixer that is used to calculate the volume of slurry in the mixer.

Inventors

Matthieu BAILLERGEAU
Abderahim RYADI
ANDREA RANZANI DA COSTA
Hamouda Jaffel

Assignees

SAINT-GOBAIN PLACO

Dates

Publication Date: 20260507
Application Date: 20231206
Priority Date: 20221213

Claims (15)

1 - 12 . (canceled)
13 . A mixer for the mixing of a cementitious slurry, the mixer comprising: an inlet for receiving a cementitious material and water; a mixing member configured to mix the cementitious material and water to form a cementitious slurry; an outlet for dispensing the cementitious slurry; a sensor configured to measure a parameter of the cementitious slurry; and a processor configured to use the parameter measurement to calculate a volume of the cementitious slurry in the mixer; wherein the sensor comprises an array of thermocouples; or the sensor comprises an infrared camera, and the mixer comprises an IR window configured to allow the transmission of infrared radiation from the cementitious slurry inside the mixer to the IR camera outside.
14 . The mixer of claim 13 , wherein the sensor comprises the array of thermocouples.
15 . The mixer of claim 13 , wherein the sensor comprises the infrared camera and the mixer comprises the IR window configured to allow the transmission of infrared radiation from the cementitious slurry inside the mixer to the IR camera outside
16 . The mixer of claim 13 , wherein the processor is further configured to calculate a slurry volume fraction of the mixer wherein the slurry volume fraction is defined according to the following formula: Slurry ⁢ volume ⁢ fraction = V ⁢ olume ⁢ of ⁢ slurry ⁢ in ⁢ the ⁢ mixer Total ⁢ volume ⁢ of ⁢ the ⁢ mixer
17 . The mixer of claim 13 , wherein the processor is further configured to change at least one of an input parameter, a process parameter, and an output parameter of the mixer in response to the calculated volume of cementitious slurry in the mixer and/or the slurry volume fraction of the mixer.
18 . The mixer of claim 13 , wherein the input parameter is selected from the list consisting of: a line speed, an input speed, an input volumetric flow rate, an input temperature or the composition of the slurry.
19 . The mixer of claim 13 , wherein the process parameter is a mixing speed or a mixing temperature.
20 . The mixer of claim 13 , wherein the output parameter is selected from the list consisting of: a mixer output speed, an output volume, an output temperature or an outlet cross-section.
21 . A process for the manufacture of a cementitious board, the process comprising: forming a slurry of water and cementitious material; mixing the slurry in a mixer; measuring a parameter of the slurry in the mixer using a sensor and calculating a volume of the slurry in the mixer using the measured parameter; depositing the slurry to form a board precursor; and drying the board precursor to form a cementitious board; wherein the sensor comprises an array of thermocouples; or the sensor comprises an infrared camera, and the mixer comprises an IR window configured to allow the transmission of infrared radiation from the cementitious slurry inside the mixer to the IR camera outside.
22 . The process of claim 21 , wherein the sensor comprises the array of thermocouples.
23 . The process of claim 21 , wherein the sensor comprises the infrared camera, and the mixer comprises the IR window configured to allow the transmission of infrared radiation from the cementitious slurry inside the mixer to the IR camera outside
24 . The process of claim 21 , wherein the process further comprises calculating a slurry volume fraction from the slurry volume, wherein the slurry volume fraction is defined according to the following formula: Slurry ⁢ volume ⁢ fraction = V ⁢ olume ⁢ of ⁢ slurry ⁢ in ⁢ the ⁢ mixer Total ⁢ volume ⁢ of ⁢ the ⁢ mixer
25 . The process of claim 21 , wherein the process further comprises changing at least one of an input parameter, a process parameter, and an output parameter in response to the calculated volume and/or slurry volume fraction.
26 . The process of claim 21 , wherein the measurement of the parameter of the slurry is substantially continuous.

Description

FIELD OF THE DISCLOSURE The present disclosure relates generally to mixers and processes for the mixing, monitoring, and dispensing of cementitious slurries. BACKGROUND During cementitious board manufacture, a cementitious slurry is mixed within and dispensed from a mixer. If the volume of slurry in the mixer is too large or too small, these deviations in volume can result in problems with the manufacturing process and/or the cementitious board product itself. For example, where the volume of slurry in the mixer diverges from what is expected, the slurry may include lumps and/or the cementitious product may include unwanted voids. Generally slurry mixers comprise mixing members that mix the slurry. Additionally, slurry mixers may comprise scrapers that clean deposited slurry from the walls of the mixer. Slurry mixers are therefore poorly accessible and, therefore, it can be challenging to monitor the volume of slurry within. Current methods for controlling and/or monitoring the slurry volume fraction within a mixer use estimations based on ideal mixers with no stagnant zones or short circuits. In reality, mixers are not ideal, and it would be useful to monitor the actual mixer volume and slurry volume fraction. With this in mind, pigments can be added to the slurry and a camera used to calculate the concentration of the pigment within the slurry and estimate the slurry volume fraction. However, this method contaminates the slurry with pigment and cannot be applied continuously. Additionally, any contact between the slurry and sensitive equipment within the mixer can damage that equipment. As such, current methods whether based on theoretical calculations of mean residence time or more physical approaches cannot provide a continuous and reliable measurement of the slurry volume fraction within a mixer. Aspects of the present disclosure seek to provide mixers and mixing processes that alleviate these problems with prior known systems. In particular, aspects of the present disclosure seek to provide improved mixers and mixing processes able to monitor the volume of slurry in the mixer. SUMMARY According to a first aspect of the present disclosure, there is provided a mixer for the mixing of a cementitious slurry, the mixer comprising: an inlet for receiving a cementitious material and water; a mixing member configured to mix the cementitious material and water to form a cementitious slurry; an outlet for dispensing the cementitious slurry; a sensor configured to measure a parameter of the cementitious slurry; and a processor configured to use the parameter measurement to calculate a volume of the cementitious slurry in the mixer. In this way, the mixer allows the volume of the slurry in the mixer to be monitored without polluting the slurry in order to avoid issues with the process and product. In some embodiments, the processor is further configured to calculate a slurry volume fraction of the mixer wherein the slurry volume fraction is defined according to the following formula: Slurry⁢ volume⁢ fraction=V⁢olume⁢ of⁢ slurry⁢ in⁢ the⁢ mixerTotal⁢ volume⁢ of⁢ the⁢ mixer In this way, the slurry volume fraction can be used to determine an improved mixer size and geometry for different line speeds to optimise the slurry volume fraction to avoid issues with the process and product. Additionally, calculating the slurry volume fraction allows for a simpler comparison and adjustment for mixers of different sizes. In some embodiments, the processor is further configured to change at least one of an input parameter, a process parameter, and an output parameter of the mixer in response to the calculated volume of cementitious slurry in the mixer and/or the slurry volume fraction of the mixer. In this way, the volume of slurry in the mixer can be adjusted to improve the process and product. For example, if the volume of slurry is higher than desired, the rate input of slurry components into the mixer may be reduced or the rate of output of slurry from the mixer may be increased. If the volume of slurry is lower than desired, the rate of slurry components input into the mixer may be increased or the rate of slurry output from the mixer may be decreased. In some embodiments, the input parameter is selected from the list consisting of: the line speed, rate of input of slurry components into the mixer, input volumetric flow rate (e.g. the volume of materials entering in mixer per second), input temperature (e.g. the temperature of one or more materials entering the mixer), or the composition of the slurry. In some embodiments, the process parameter is the mixing speed (e.g. the speed of one or more mixing members within the mixer) or the mixing temperature (e.g. the temperature of the slurry within the mixer). In some embodiments, the output parameter is selected from the list consisting of: the line speed, mixer output speed (e.g. the speed of material exiting the mixer), output volumetric flow rate (e.