Apparatus and method for the production of a plaster slurry

Patent metadata

Field	Value
Publication number	US-12521907-B2
Application number	US-202017641902-A
Country	US
Kind code	B2
Filing date	Dec 9, 2020
Priority date	Dec 10, 2019
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

An apparatus ( 100 ) for the production of a plaster slurry is described, the apparatus ( 100 ) comprising a mixer ( 102 ) for mixing at least plaster and water to form a plaster slurry, the mixer ( 102 ) comprising an outlet conduit ( 122 ), a foam generator ( 106 ) for mixing at least air, a foaming agent and water to produce a foam, the foam generator ( 106 ) in fluid communication with the mixer ( 102 ) via a fluid pathway ( 116 ) comprising a foam conduit ( 117 ); and a mass flow meter ( 124 ), wherein the mass flow meter ( 124 ) is configured to measure the density and mass flow rate of the foam within the foam conduit ( 117 ) or the plaster slurry within the outlet conduit ( 122 ). Additionally, a method of manufacturing a plaster slurry is described.

First claim

The invention claimed is:

1 . An apparatus for the production of a plaster slurry, said apparatus comprising:
a mixer for mixing at least plaster and water to form a plaster slurry, said mixer comprising an outlet conduit; a foam generator for mixing at least air, a foaming agent and water to produce a foam, said foam generator in fluid communication with said mixer via a fluid pathway comprising a foam conduit; a mass flow meter, and a control system configured to vary the density of said foam within said foam conduit or said plaster slurry within said outlet conduit; said mass flow meter configured to measure the density and mass flow rate of:
said foam within said foam conduit, or
said plaster slurry within said outlet conduit, and
wherein the apparatus further comprises at least one sensor configured to measure the pressure at the entrance and/or exit of said mass flow meter, and characterised in that said control system is configured to correct the measured density using a measurement from the at least one sensor.

2 . The apparatus of claim 1 , wherein said foam conduit extends between said foam generator and said mixer.

3 . The apparatus of claim 1 , wherein said foam conduit extends between said foam generator and said outlet conduit.

4 . The apparatus of claim 3 , wherein said mass flow meter is positioned downstream of said foam conduit.

5 . The apparatus of claim 1 , wherein said control system is configured to increase the air within said foam generator, or decrease the water within said foam generator, or increase the air within said foam generator and decrease the water within said foam generator, if said measured density is above a target density.

6 . The apparatus of claim 5 , wherein said target density is a range of density values.

7 . The apparatus of claim 1 , wherein said control system is configured to decrease the air within said foam generator, or increase the water within said foam generator, or decrease the air within said foam generator and increase the water within said foam generator, if said measured density is below a target density.

8 . The apparatus of claim 7 , wherein said target density is a range of density values.

9 . The apparatus of claim 1 , wherein the apparatus further comprises at least one sensor configured to measure the temperature of the material entering or exiting said mass flow meter.

10 . The apparatus of claim 1 , wherein said mass flow meter comprises two parallel resonating channels and a signal converter, where said mass flow meter has a curved dual tube design.

11 . The apparatus of claim 1 , wherein said apparatus comprises at least two mass flow meters, a first mass flow meter configured to measure the density and mass flow rate of said foam within said foam conduit and a second mass flow meter configured to measure the density and mass flow rate of said plaster slurry within said outlet conduit.

12 . The apparatus of claim 1 , wherein said foam generator is in fluid communication with said mixer via a plurality of fluid pathways, each fluid pathway comprising a foam conduit, and said apparatus further comprises at least two mass flow meters, each mass flow meter configured to measure the density and mass flow rate of said foam within a different foam conduit.

13 . The apparatus of claim 1 , wherein said apparatus comprises a plurality of outlet conduits, said apparatus further comprising at least two mass flow meters, each mass flow meter configured to measure the density and mass flow rate of said plaster slurry within a different outlet conduit.

14 . A method for manufacturing a plaster slurry using the apparatus of claim 1 , said method comprising:
mixing materials comprising at least plaster and water to form said plaster slurry in said mixer; mixing at least air, said foaming agent and water to produce said foam in said foam generator, measuring the density and mass flow rate of said foam within said foam conduit or said gypsum slurry within said outlet conduit using said mass flow meter, measuring the pressure at the entrance and/or exit of said mass flow meter, and characterised in that the method further comprises the step of correcting the measured density using the measurement from the at least one sensor.

15 . The apparatus of claim 1 , wherein said mass flow meter is configured to continuously measure the density and mass flow rate of:
said foam within said foam conduit; or said plaster slurry within said outlet conduit.

16 . The apparatus of claim 1 , wherein said control system is configured to correct said measured density assuming said foam is an ideal gas.

17 . The apparatus of claim 1 , wherein said apparatus comprises a pair of pressure sensors.

18 . The apparatus of claim 1 , wherein said control system comprises a proportional-integral-derivative controller.

19 . The apparatus of claim 1 , wherein said apparatus is configured to use the corrected measured density to calculate a volume flow rate.

20 . The apparatus of claim 1 , wherein said foam conduit is split into multiple conduits and wherein each foam conduit comprises a foam flow meter in combination with a valve, wherein said valve is configured to control the amount of foam flowing through each foam conduit.

21 . The apparatus of claim 1 , wherein said control system is configured to vary the mass flow rate of said foam within said foam conduit.

Assignees

• Saint Gobain Placo

Inventors

• Jaffel Hamouda
• Morlat Richard
• Ranzani Da Costa Andrea

Classifications

• G01N11/04

  through a restricted passage, e.g. tube, aperture · CPC title

• G01F1/8477

  with multiple measuring conduits · CPC title

• C04B38/10

  by using foaming agents (C04B38/02 takes precedence){or by using mechanical means, e.g. adding preformed foam} · CPC title

• C04B11/00

  Calcium sulfate cements · CPC title

• B28C7/024

  by measuring properties of the mixture, e.g. moisture, electrical resistivity, density · CPC title