Grey water measurement

Patent metadata

Field	Value
Publication number	US-11385153-B2
Application number	US-201816316752-A
Country	US
Kind code	B2
Filing date	Aug 9, 2018
Priority date	Aug 11, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

Method and system to measure and monitor the grey water content in a rotating concrete mixer drum mixer truck using a sensor attached to the interior of the concrete mixer drum. By measuring the grey water content before a batching process takes place, the batched water (and cement content and admixture type and content) can be modified in order to maintain expected performance of the batched load in terms of both strength and rheology, or more simply, some or all of the grey water can be discharged from the concrete mixer drum before batching.

First claim

What is claimed is:

1. A method for determining the grey water content remaining in a mixer drum from a previous concrete load that has been discharged from said mixer drum to provide accurate batching of a new concrete load into said mixer drum, said method comprising:
(A) providing a concrete mixer drum having an interior volume and an axis of rotation;
(B) providing at least one sensor mounted in a location in said interior volume of said mixer drum such that during a revolution of said mixer drum, the sensor separately achieves both a submerged state in any water in said interior and an unsubmerged state and generates a signal indicative of each said state;
(C) rotating the concrete mixer drum such that the sensor separately achieves both a submerged state in any water in said interior and an unsubmerged state;
(D) determining the angle between the axis of rotation of the concrete mixer drum and horizontal;
(E) determining the submersion fraction or inverse fraction that the sensor achieves based on the rotation of Step (C);
(F) providing data correlating the submersion fraction or inverse fraction to the corresponding volume of water in a vessel that is substantially geometrically similar to said mixer drum;
(G) determining the grey water content in said mixer drum by comparing the submersion fraction determined in Step (E) with said data of Step (F) and the angle between the axis of rotation of the concrete mixer drum and horizontal determined in Step (D); and either
(H) creating an alert if the grey water content detected is greater than a pre-defined limit, modifying the percentage of water in said new concrete load, based upon the grey water content determined in step (G), discharging at least a portion of the grey water from said mixer drum based upon the grey water content determined in step (G), or a combination thereof.

2. The method of claim 1 , wherein said concrete mixer drum is mounted on a truck.

3. The method of claim 1 , wherein said at least one sensor is an electrical resistivity sensor, an electrical capacitance sensor, an acoustic sensor, a microwave sensor, a nuclear resonance sensor, or a light sensor.

4. The method of claim 1 , wherein said mixer drum has a length and a motor for rotating said mixer drum, and wherein said at least one sensor is located in the bottom third along the length of the mixer drum, closest to said motor.

5. The method of claim 1 , wherein said at least one sensor is located less than 8 inches from the internal surface of the mixer drum.

6. The method of claim 1 , wherein said at least one sensor is located less than 2 inches from the internal surface of the mixer drum.

7. The method of claim 1 , wherein said at least one sensor is located less than inches from the internal surface of the mixer drum.

8. The method of claim 1 , wherein said at least one sensor makes a measurement at least 5 times per second for drum rotational speeds less than or equal to 2 revolutions per minute.

9. The method of claim 1 , wherein said at least one sensor makes a measurement at least 15 times per second for drum rotational speeds less than or equal to 6 revolutions per minute but greater than 2 revolutions per minute.

10. The method of claim 1 , wherein said at least one sensor makes a measurement at least 50 times per second for drum rotational speeds greater than 6 revolutions per minute.

11. The method of claim 1 , wherein the angle determined in Step (D) is provided by an accelerometer mounted on the drum.

12. The method of claim 1 , wherein the submersion fraction or inverse fraction determined in Step (E) is based on the variability of the sensor output.

13. The method of claim 1 , wherein the submersion fraction or inverse fraction determined in Step (E) is based on the time the sensor detects grey water compared to the total time to complete a drum revolution.

14. The method of claim 13 , wherein the total time to complete said revolution is based on the mixer drum revolution speed.

15. The method of claim 1 , wherein the submersion fraction determined in Step (E) is based on the distance said at least one sensor traveled while detecting grey water compared to the total distance traveled to complete a drum revolution.

16. The method of claim 15 , wherein the position of said at least one sensor is determined by an accelerometer mounted to the mixer drum.

17. The method of claim 1 , wherein the data generated in Step (F) is based on a collection of data representing the geometry of the mixer drum and location of said at least one sensor in three-dimensions.

18. The method of claim 1 , wherein the data generated in Step (F) is based on sensor outputs corresponding to at least two measured volumes of water in said substantially geometrically similar vessel.

19. The method of claim 1 , wherein the grey water content is determined based on at least three successive rotations of the mixer drum.

20. The method of claim 1 , wherein said mixer drum has an interior surface, said method further comprising determining the amount of water adhering to said interior surface of said mixer drum, and modifying the amount of grey water content determined in step (G) based upon said determination.

21. The method of claim 1 , further comprising determining the amount of hardened concrete built up within said mixer drum, and modifying the amount of grey water content determined in step (G) based upon said determination.

22. The method of claim 1 , wherein said new concrete load comprises water and cement, and wherein said percentage of water in said new concrete load is modified by adjusting the water content, the cement content, or both.

23. A method of determining the volume of grey water remaining in a vessel having an interior volume and an axis of rotation after a first cement load has been discharged from said vessel, said method comprising:
rotating said vessel at least one complete revolution and determining the angle of the axis of rotation of said vessel with respect to horizontal;
providing at least one sensor in said interior volume positioned so as to be submerged in the grey water in said vessel during a first portion of said one complete revolution and not submerged in the grey water in said vessel during a second portion of said one complete revolution, said at least one sensor generating a first signal when it is submerged and a second signal when it is not submerged;
determining the ratio of either said first portion or said second portion to said one complete revolution;
determining the angle between the axis of rotation of the concrete mixer drum and horizontal;
comparing said ratio to a predetermined ratio indicative of the volume of grey water in said vessel; and
modifying the percentage of water in a second cement load to be loaded into said vessel based on said comparison and said angle between the axis of rotation of the concrete mixer drum and horizontal.

24. A method of determining the volume of grey water remaining in a vessel having an interior volume and an axis of rotation after a first cement load has been discharged from said vessel, said method comprising:
rotating said vessel at least one complete revolution and determining the angle of the axis of rotation of said vessel with respect to horizontal;
providing at least one sensor in said interior volume positioned so as to be submerged in the grey water in said vessel during a first portion of said one complete revolution and

Assignees

• Gcp Applied Tech Inc

Inventors

• Roberts Mark
• Tregger Nathan
• Klaus Stephen

Classifications

• B28C5/422

  Controlling or measuring devices (B28C5/4227 takes precedence) · CPC title

• B28C5/4203

  Details; Accessories · CPC title

• B28C5/42 Primary

  Apparatus specially adapted for being mounted on vehicles with provision for mixing during transport ({B28C5/1893 takes precedence; mounted on a wheelbarrow B28C5/1215, B28C5/1818, B28C5/2018; } vehicle aspect B60P3/16) · CPC title

• G01N11/00

  Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties · CPC title

• B28C7/0404

  Proportioning · CPC title