SOLID CHEMICAL PRODUCT DILUTION CONTROL

• US 20110284090A1
• Filed: 05/20/2010
• Published: 11/24/2011
• Est. Priority Date: 05/20/2010
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Inventors: Mehus, Richard J., Tischler, Sherri L., Kraus, Paul R., Popa, Mihnea A., Otting, Blake Roberts
• Granted Patent: US 8,602,069 B2
• Time in Patent Office: Days
• US Class Current: 137/2
• CPC Class Codes: B01F 21/22 using additional holders in conduits, containers or pools for keeping the solid material in place, e.g. supports or receptacles
• CPC Class Codes: B01F 35/2132 Concentration, pH, pOH, p(ION) or oxygen-demand B01F35/2133 takes precedence
• CPC Class Codes: B01L 3/0293 for liquids
• CPC Class Codes: B65B 3/28 by weighing
• CPC Class Codes: Y10T 137/0324 With control of flow by a condition or characteristic of a fluid
• CPC Class Codes: Y10T 137/8158 With indicator, register, recorder, alarm or inspection means

Abstract

A solid chemical product is dispensed to prepare a requested amount of a use solution having a requested concentration of the chemical product. In some examples, a target amount of a diluent and a target amount of the chemical product required to prepare the requested use solution are determined. The target amount of the diluent is dispensed into a container. At least some of the diluent in the container is applied to the solid chemical product to create a resultant use solution, which is directed back into the container. The diluent from the container is applied to the chemical product until the amount of the use solution in the container satisfies the requested amount. In some examples, the target amount of the diluent and the target amount of the chemical product are measured by weight.

Claims

1. A method comprising:

dispensing a target amount of a diluent into a container; and

applying at least some of the diluent from the container to a solid chemical product and directing the resulting use solution back into the container until an amount of the use solution in the container satisfies a requested amount.

2. The method of claim 1, wherein applying the diluent comprises spraying at least some of the diluent from the container onto the solid chemical product.

3. The method of claim 1, further comprising:

receiving a dispense request specifying a requested volume of the use solution and a requested concentration of the chemical product in the use solution;

determining a target weight of the diluent required to prepare the requested use solution; and

determining a target weight of the chemical product to be dispensed required to prepare the requested use solution.

4. The method of claim 1, wherein dispensing a target amount of a diluent into the container further comprises:

electronically controlling a valve through which the diluent is dispensed into the container;

receiving container weight information from a weighing device positioned to measure the weight of the container;

determining a weight of the diluent in the container from the container weight information;

comparing the weight of the diluent in the container to a target weight of the diluent required to prepare the requested use solution; and

electronically controlling the valve to stop dispensation of the diluent into the container based on the comparison.

5. The method of claim 1, wherein applying the diluent to dispense a solid chemical product further comprises:

initiating a spray on/off cycle including spraying the solid chemical product with at least some of the diluent from the container for a first predetermined period of time and stopping the spraying of the solid chemical product for a second predetermined period of time;

receiving container weight information from a weighing device positioned to measure the weight of the container;

determining a weight of the use solution in the container from the container weight information;

comparing the difference between a target weight of the requested use solution and the weight of the use solution in the container with a threshold; and

repeating the spray on/off cycle until the threshold is satisfied.

6. The method of claim 1 wherein applying the diluent to the solid chemical product erodes or dissolves the solid chemical product to produce the resulting use solution.

7. The method of claim 1, wherein applying the diluent to dispense a solid chemical product further comprises:

spraying the solid chemical product with at least some of the diluent from the container;

sampling container weight information from a weighing device positioned to measure the weight of the container;

determining a weight of the use solution in the container from the container weight information;

after a dynamic settling time has elapsed, determining a dispense rate corresponding to an amount of the chemical product dispensed per unit time based on a change in the weight of the use solution in the container;

determining a dynamic target weight of the use solution in the container based on a target weight of the requested use solution;

determining a dynamic cycle time based on the dynamic target and the dispense rate; and

stopping the spraying of the chemical product after the dynamic cycle time has elapsed.

8. The method of claim 7, further comprising defining the dynamic target as a percentage of the difference between the target weight of the requested use solution and the difference between an actual weight of diluent in the container determined when the target amount of diluent has been dispensed into the container and the minimum weight of the use solution in the container after starting the spraying of the solid chemical product.

9. A system comprising:

a container into which a target amount of a diluent required to prepare a requested amount of a use solution is dispensed;

a weighing device positioned to obtain container weight information concerning a weight of the container and any contents thereof; and

a controller that receives a dispense request specifying a requested volume of the use solution to be prepared and a requested concentration of the chemical product in the use solution, determines a target weight of the diluent required to prepare the requested use solution, determines a target weight of the chemical product to be dispensed required to prepare the requested use solution, and manages application of the diluent onto the solid chemical product until an amount of the use solution in the container satisfies the requested amount based on the container weight information.

10. The system of claim 9 wherein the solid chemical product comprises one of a solid block of chemical product concentrate, pellets, tablets, a cast product, or an extruded product.

11. The system of claim 9 wherein the weighing device comprises one or more load cells.

12. The system of claim 9 further comprising a liquid circulation subsystem that draws diluent from the container and sprays the diluent onto a solid chemical product to be dispensed and directs the resulting use solution back into the container under control of the controller.

13. The system of claim 9 wherein the controller further:

electronically controls a valve through which the diluent is dispensed into the container;

receives the container weight information;

determines a weight of the diluent in the container from the container weight information;

compares the weight of the diluent in the container to the target weight of the diluent required to prepare the requested use solution; and

electronically controls the valve to stop dispensation of the diluent into the container based on the comparison.

14. The system of claim 9 wherein the controller further:

initiates a spray on/off cycle including spraying the solid chemical product with at least some of the diluent from the container for a first predetermined period of time, and stops the spraying of the solid chemical product for a second predetermined period of time;

receives the container weight information;

determines a weight of the use solution in the container from the container weight information;

compares the difference between a target weight of the requested use solution and the weight of the use solution in the container with a threshold; and

repeats the spray on/off cycle until the threshold is satisfied.

15. The system of claim 9 wherein the controller further:

controls spraying of the solid chemical product with at least some of the diluent from the container;

samples the container weight information;

determines a weight of the use solution in the container from the container weight information;

after a dynamic settling time has elapsed, determines a dispense rate corresponding to an amount of the chemical product dispensed per unit time based on a change in the weight of the use solution in the container;

determines a dynamic target weight of the use solution in the container based on a target weight of the requested use solution;

determines a dynamic cycle time based on the dynamic target and the dispense rate; and

stops the spraying of the chemical product after the dynamic cycle time has elapsed.

16. The system of claim 9 further comprising a memory that stores dispenser settings.

17. The system of claim 9 further comprising a memory that stores at least one of a timed dispense module, an adjusted single-shot dispense module, and an adjusted multi-shot dispense module.

18. The system of claim 17 wherein the timed dispense module controls dispensation based on a spray on/off cycle comprising application of the diluent to the solid block of chemical product for a first predetermined period of time, stopping application for a second predetermined period of time, and repeating the spray on/off cycle until the amount of use solution in the container satisfies the requested amount.

19. The system of claim 17 wherein the adjusted single-shot dispense module controls dispensation based on a determination of a current dispense rate and a prediction of a time at which the actual amount of use solution in the container satisfies the requested amount of use solution.

20. The system of claim 17 wherein the adjusted multi-shot dispense module controls dispensation based on a determination of a current dispense rate and a prediction of a time at which the actual amount of use solution in the container satisfies a predetermined percentage of the requested amount of use solution.