Method and means for sand reblending

• US 6,871,757 B2
• Filed: 01/03/2003
• Issued: 03/29/2005
• Est. Priority Date: 01/03/2003
• Status: Active Grant

• Current Assignee: Superior Industries Incorporated
• Original Assignee: Greystone, Inc. (Superior Industries LLC)
• Inventors: Squires, Franklin E, Bennington, William J. II
• Primary Examiner(s): NICOLAS, FREDERICK C
• Application Number:
  US10/336,494
• Publication Number:
  US 20040144797A1
• Time in Patent Office: 816 Days
• Field of Search: 222/1, 222/23, 222/30, 222/52, 222/64, 222/129, 222132-135, 222/144.5, 222/145.1, 222/145.5, 222/145.6, 222/644, 209/488, 209/491, 209/464, 209/483
• US Class Current: 222/1
• CPC Class Codes: B03B 13/00 Control arrangements specially adapted for wet-separating apparatus or for dressing plant, using physical effects
• CPC Class Codes: B03B 9/00 General arrangement of separating plant, e.g. flow sheets
• CPC Class Codes: G01F 1/007 by measuring the level variations of storage tanks relative to the time
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

A method and apparatus for reblending sand whereby multiple reblending tanks with a plurality of reblending stations have thin respective outputs joined through a single control system.

Claims

1. A method of reblending a mixture of aggregates, comprising,

providing classification tanks with a plurality of stations to receive a raw feed input slurry comprising fluid and a mixture of aggregates of a plurality of mesh sizes, each station having at least a primary product discharge valve and a waste product discharge valve;

providing a single computer connected to the primary product discharge valve, the waste product discharge valve, and a bed level sensor at each station which must be tripped for the primary product discharge valve and waste discharge valve to be opened;

inputting into the computer an initial data set for startup including an initial Station Analysis matrix and initial discharge flow rates;

calibrating the tanks and computer for the given location by setting the primary product discharge valve at each station open 100%, delivering the input slurry to the tank, running the tank for a given calibration cycle time, sampling and sieve testing aggregate from the given location to approximate the distribution of mesh sizes contained in the input slurry, sampling and sieve testing aggregate discharged by the tanks at each station respectively, and inputting the test results into the computer so as to develop a mathematical model of the tank including an initial Product A array, a Calibrated Station Analysis Matrix of actual tank performance in terms of individual percent retained for each mesh size at each station, and a matrix of discharge flow rate multipliers that reconciles the input slurry with the sampled aggregate discharged by the tank during calibration;

inputting into the computer predetermined content specifications for a primary product including high and low percentages of aggregates capable of passing through a given series of progressively smaller mesh sizes;

simulating in the computer that the tanks have been run in a production mode for a given cycle time;

comparing the simulated output gradation of the tanks with the predetermined content specifications and identifying any variances therefrom;

determining which of the variances are the greatest and which of the mesh sizes is associated therewith;

progressively and sequentially searching through each station in the Product A array to identify a marker station that would first reduce said greatest variance if the primary product discharge valve associated with the station were closed a portion of the given cycle time;

searching the Calibrated Station Analysis Matrix, beginning at the marker station and continuing through all subsequent stations to find a station having the highest percent retained value for the next smaller mesh size than the mesh size with the greatest variance;

simulating setting the primary product discharge valve to be open a lower percentage of the given cycle time at the station having the highest percent retained value from the previous step;

calculating a revised Product A Matrix and replacing the raw input feed with a projected resultant gradation output by the tank based upon the previous step;

repeating the foregoing simulation and searching steps for any other mesh sizes which exhibit nonzero variance values, so that all variations from the content specifications have been considered and eliminated if possible;

establishing target percent open time settings for the primary product discharge valves at each station for a production cycle based upon the above simulations and calculations;

running the tanks in a production mode for a production cycle time using the target percent open settings for the valves as determined by the most recent computer simulations and calculations;

monitoring and recording the actual open times of the primary product discharge valves allowed by the bed level sensors during the production cycle time and relaying said information to the computer;

recalculating the flow discharge rates, the raw feed input, and the variances based upon the actual valve open times recorded; and

repeating the foregoing steps before a next production cycle as needed to keep the resultant gradation of the primary product in compliance with the predetermined content specifications.

2. The method of claim 1 wherein the operation of the tanks is conducted concurrently in unison.

3. The method of claim 1 wherein blended material is discharged by each tank and combined into a single mass of blended material.

4. The method of claim 2 wherein blended material is discharged by each tank and combined into a single mass of blended material.

5. The method of claim 3 wherein blended material is discharged by each tank and combined into a single mass of blended material.

6. An apparatus for sand reblending, comprising, two or more classification tanks with a plurality of stations to receive a raw feed input slurry comprising fluid and a mixture of aggregates of a plurality of mesh sizes, each station having at least a primary product discharge valve and a waste product discharge valve;

means for providing a computer connected to a programmable logic single controller or PLCs (just a switch gear as told by the controller) primary product discharge valve, the waste product discharge valve, and a bed level sensor at each station which must be tripped for the primary product discharge valve and waste discharge valve to be opened;

means for inputting into the computer an initial data set for startup including an initial Station Analysis matrix and initial discharge flow rates;

means for calibrating the tanks and computer for the given location by setting the primary product discharge valve at each station open 100%, delivering the input slurry to the tank, running the tank for a given calibration cycle time, sampling and sieve testing aggregate from the given location to approximate the distribution of mesh sizes contained in the input slurry, sampling and sieve testing aggregate discharged by the tanks at each station respectively, and inputting the test results into the computer so as to develop a mathematical model of the tank including an initial Product A array, a Calibrated Station Analysis Matrix of actual tank performance in terms of individual percent retained for each mesh size at each station, and a matrix of discharge flow rate multipliers that reconciles the input slurry with the sampled aggregate discharged by the tank during calibration;

means for inputting into the computer predetermined content specifications for a primary product including high and low percentages of aggregates capable of passing through a given series of progressively smaller mesh sizes;

means for simulating in the computer that the tanks have been run in a production mode for a given cycle time;

means for comparing the simulated output gradation of the tanks with the predetermined content specifications and identifying any variances therefrom;

means for determining which of the variances are the greatest and which of the mesh sizes is associated therewith;

means for progressively and sequentially searching through each station in the Product A array to identify a marker station that would first reduce said greatest variance if the primary product discharge valve associated with the station were closed a portion of the given cycle time;

means for searching the Calibrated Station Analysis Matrix, beginning at the marker station and continuing through all subsequent stations to find a station having the highest percent retained value for the next smaller mesh size than the mesh size with the greatest variance;

means for simulating setting the primary product discharge valve to be open a lower percentage of the given cycle time at the station having the highest percent retained value from the previous step;

means for calculating a revised Product A Matrix and replacing the raw input feed with a projected resultant gradation output by the tank based upon the previous step;

means for repeating the foregoing simulation and searching steps for any other mesh sizes which exhibit nonzero variance values, so that all variations from the content specifications have been considered and eliminated if possible;

means for establishing target percent open time settings for the primary product discharge valves at each station for a production cycle based upon the above simulations and calculations;

means for running the tanks in a production mode for a production cycle time using the target percent open settings for the valves as determined by the most recent computer simulations and calculations;

means for monitoring and recording the actual open times of the primary product discharge valves allowed by the bed level sensors during the production cycle time and relaying said information to the computer; and

means for recalculating the flow discharge rates, the raw feed input, and the variances based upon the actual valve open times recorded.

7. The method of claim 6 wherein means for the operation of the tanks is conducted concurrently in unison.

8. The method of claim 6 wherein means for blended material is discharged by each tank and combined into a single mass of blended material.

9. The method of claim 6 wherein means for blended material is discharged by each tank and combined into a single mass of blended material.

10. The method of claim 6 wherein means for blended material is discharged by each tank and combined into a single mass of blended material.