Continuous liquid stream digital blending system

• US 6,186,193 B1
• Filed: 05/19/1998
• Issued: 02/13/2001
• Est. Priority Date: 11/15/1996
• Status: Expired due to Term

• Current Assignee: Oden Machinery, Inc.
• Original Assignee: ODEN Corporation
• Inventors: Millett, Peter B. Jr., Phallen, Iver J., Jezuit, Richard J. Jr.
• Primary Examiner(s): Walczak, David J.
• Assistant Examiner(s): DEVORE, PETER T
• Application Number:
  US09/081,195
• Time in Patent Office: 1,001 Days
• Field of Search: 141/83, 141/9, 141/98, 141/99, 141/104, 141/105, 141/192, 141/198, 222/56, 222/61, 222/63, 222/64, 222/71, 222/129, 222/132, 222/134, 222/135, 222/255, 222/638, 222/639, 222/642, 222/644, 222/1, 364/479.09, 366/179.1
• US Class Current: 141/83
• CPC Class Codes: B65B 3/30 by volumetric measurement
• CPC Class Codes: G01F 1/84 Coriolis or gyroscopic mass flowmeters
• CPC Class Codes: G01G 17/04 for weighing fluids, e.g. gases, pastes
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: G05D 11/137 by sensing the density of the mixture

Abstract

The present invention consists of a method and apparatus providing for the continuous stream blending, preferably on a mass ratio basis, of two or more liquids. Each individual liquid stream is synchronously dosed in precise mass ratio to a common mixing point. The flow of each stream is on-off or digital. Repeated mass ratio doses of defined and matching flow interval, referred to as synchronous digital flow, interspersed with a defined interval of no flow, constitutes digital flow at a net rate sufficient to meet or exceed some required take-away of the blended liquids. In one preferred embodiment, each dose stream flow is produced and measured by a four element apparatus preferably consisting of a servo motor and controller, a precision positive displacement pump, a Coriolis mass meter and a precision flow stream shut-off device. The servo motor and controller establish and control a periodic and intermittent flow rate necessary to displace a defined mass dose in a precisely defined flow interval. The flow interval is measured against a precision millisecond digital clock. The Coriolis mass meter is used only to totalize mass flow to define the desired mass dose during the defined digital flow interval. The flow stream shut-off device ensures precise delivery of the mass dose to the common mixing point. The flow rate of a stream is automatically adjusted by the control electronics until the required mass dose is delivered in the defined flow interval.

Claims

1. Method for continuous liquid stream digital blending comprising the following steps;

providing two or more bulk supply sources of liquid products to be blended, providing a liquid flow meter downstream of each bulk supply source, providing a mixing chamber downstream of the liquid flow meters, providing a dose stream delivery assembly downstream of each liquid bulk supply for delivering small flow doses of liquid product from the associated bulk supply source through the flow meter to the mixing chamber, and providing a final blend container downstream of the mixing chamber;

using the dose stream delivery assemblies to simultaneously deliver small doses of liquid product from each of the two or more bulk supply sources through each respective flow meter and into the mixing chamber, the start of flow and the end of flow of each dose or each dose stream delivery assembly being synchronized with the start and end of flow of all other dose stream assemblies;

using the liquid flow meters to determine the quantity of each dose of liquid being delivered; and

repeating the foregoing steps a number of times to create a desired net flow rate of ratio blended liquid products from the mixing chamber into the final blend container.

2. The method for continuous liquid stream digital blending as set forth in claim 1 wherein the final blend container is a tank and further characterized by the additional step of discharging the ratio blended products from the final blend tank in a continuous stream basis.

3. The method for continuous liquid stream digital blending as set forth in claim 2 wherein the discharge from the final blend tank on a continuous stream basis can be altered or varied through on-off modulation, any such modulation having no effect on the dosing method used to produce the blended product, save its on-off status.

4. The method for continuous liquid stream digital blending as set forth in claim 2 wherein the discharge from the final blend tank on a continuous stream basis can be controlled by use of digital or on-off flow rate control, any such control having no effect on the digital dosing method used to produce the blended product save its on-off status.

5. The method for continuous liquid stream digital blending as set forth in claim 2 wherein the discharge from the final blend tank on a continuous stream basis can be varied by any desired analog modulation of flow rate from zero to the maximum of the particular apparatus.

6. The method for continuous liquid stream digital blending as set forth in claim 2 wherein the flow rate of the continuous stream discharged from the final blend tank can be satisfied by simultaneously delivering small doses on an intermittent flow basis to the final blend tank with each intermittent flow being increased by a common factor adequate to produce net flow equal to or greater than the continuous stream take-away requirement.

7. The method for continuous liquid stream digital blending as set forth in claim 2 wherein a Coriolis mass meter may be provided downstream of the final blend tank, and using the Coriolis mass meter to sample the density of the finished liquid stream from the final blend tank to independently check the accuracy with which the final product has been blended.

8. The method for continuous stream digital blending density sampling as set forth in claim 7 wherein a Coriolis mass meter is installed downstream of the final blend tank, and using the Coriolis mass meter for continuous density sampling of the blended liquids as a means of assessing and assuring complete mixing of the streams, incomplete mixing being detected by the meter as excessive density fluctuations.

9. The method for continuous liquid stream digital blending as set forth in claim 2 characterized by the additional steps of discharging the ratio blended products from the mixing chamber to the final blend tank on an intermittent dose basis.

10. The method for continuous liquid stream digital blending as set forth in claim 9 wherein the discharge of the ratio blended product from the final blend tank can be started or stopped at will without any adverse effect upon the accuracy of the blended proportions of the liquid products.

11. The method for continuous liquid stream digital blending as set forth in claim 1 wherein the small doses are delivered in a precise ratio using flow meters, and wherein the small doses from the supply sources can be started at will and stopped at the end of any flow intervals without any adverse effect upon the accuracy of the blended ratio proportions of the liquid products.

12. The method for continuous liquid stream digital blending as set forth in claim 1 wherein each dose stream delivery assembly is a servo driven pump wherein each of the flow meters is a Coriolis mass flow meter through which each of the respective flow doses pass, and further characterized by each the Coriolis mass meter delivering a correct digital flow mass quantity to maintain the correct mass ratio, each flow rate being altered up or down in order to maintain the synchronous flow rates of all streams, such alteration being computed and implemented in the interval between dose cycles by adjustment in the pump servo drive motor velocity setting.

13. The method for continuous liquid stream digital blending as set forth in claim 1 further characterized by monitoring and adjusting if necessary the flow meter dose accuracy and synchrony of flow during each flow cycle.

14. The method for continuous liquid stream digital blending as set forth in claim 1 wherein the flow meters utilized are Coriolis mass flow meters and the mass dose delivered by each dose stream delivery assembly is based directly on a dose mass ratio formula for each liquid component of the finished liquid stream rather than on analog density alteration or analog density adjustment of constituent flow streams or analog density alteration or adjustment of the combined stream.

15. The method for continuous liquid stream digital blending as set forth in claim 1 wherein a positive shut-off dose stream injector is provided downstream of the liquid flow meter and upstream of the mixing chamber, and wherein the small synchronized flow doses are delivered through the positive shut-off injectors into the mixing chamber.

16. The method for continuous liquid stream digital blending as set forth in claim 1 wherein the final blend container is a unit of use container, and wherein a positive shut-off filing nozzle is provided downstream of the mixing chamber, and using said nozzle to fill individual unit of use containers.

17. The method for continuous liquid stream digital blending as set forth in claim 1 wherein the final blend container is a tank, and in which the blended liquid is displaced into a final blend tank and in which the capacity of the final blend tank can be as small as the equivalent of two cycles of simultaneously delivered small doses.

18. The method for continuous liquid stream digital blending as set forth in claim 1 wherein the dose required of each flow channel to achieve the desired flow rate of ratio blended products is determined by the following steps:

converting volumetric formula of the liquids in the bulk supply sources to a mass formula where mass ratio blending is required;

then multiplying by a constant to restate a ratio flow rate formula upward to a time adjusted flow adequate to accommodate system functions and cycle time;

then defining dose channel size required for each component to pre-defined dose channels;

then restating the flow rate of each dose channel to deliver the correct dose quantity in a defined time, typically 5000 ms, conversion being by multiplication of the flow per minute by the ratio of the defined flow time in seconds divided by 60 seconds;

then establishing the correct dose quantity for each stream component by entering the dose quantity established in the previous step into the control system electronics with adjustment of dose being automatically computed based on the sample dose liquid quantity;

then adjusting dose delivery time to the defined flow time for each constituent stream by ratiometrically adjusting the actual measured flow time of each stream to the defined flow time; and

then adjusting each liquid stream for simultaneous synchronous flow by operating all flow channels with each dose stream flow beginning simultaneously and repeating the previous dose delivery time adjustment step.

19. Apparatus for continuous liquid stream digital blending comprising:

two or more bulk supply sources of liquid products to be blended;

a mixing chamber in which two or more simultaneously delivered doses or liquid product are blended the mixing chamber having a discharge;

a final blend container for receiving the blended liquid products from the discharge of the mixing chamber;

dose stream delivery assemblies downstream of the bulk supply sources for simultaneously delivering small doses of liquid product from the associated bulk supply sources to the mixing chamber, there being one dose stream delivery assembly for each bulk supply source, the start of flow and the end of flow of each dose for each dose stream delivery assembly being synchronized with the start and end of flow of all other dose stream delivery assemblies to create repeated synchronized flow doses of two or more liquids which are delivered to the mixing chamber, the string of synchronized intermittent dose cycles of the dose stream delivery assemblies creating a desired net flow rate of ratio blended liquids; and

a flow meter associated with each dose stream delivery assembly and upstream of the mixing chamber, the flow meter being used to determine the quantity of each dose being delivered to the mixing chamber.

20. The apparatus for continuous liquid stream digital blending as set forth in claim 19 further comprising a precision digital clock, each of the delivery assemblies relying upon the clock signal to establish synchronous flow of two or more liquid streams by measurement of digital flow duration against the precision clock signal.

21. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein means are provided to adjust the duration of flow between the start of flow of one operating cycle and the start of flow of the next operating cycle.

22. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein the flow meter is a Coriolis mass flow meter, the mass flow meter serving only as a mass flow dose totalizer for each small dose of liquid product and not as a flow rate feedback device, and in which the mass flow dose is determined by a variable frequency digital output from the mass flow meter.

23. The apparatus for continuous liquid stream digital blending as set forth in claim 19 further characterized by the provision of at least one ribbon type in-line static mixing device downstream of the mixing chamber.

24. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein each of the dose stream delivery assemblies includes a positive shut-off dose stream injector connected downstream of each flow meter, and wherein the dose stream delivery assembly initiates liquid flow from the bulk supply through the positive shut-off dose stream injector to simultaneously deliver relatively small synchronized flow doses of liquid product to the mixing chamber.

25. The apparatus for continuous liquid stream digital blending as set forth in claim 24 in which the positive dose stream injectors are mounted on the mixing chamber is such a manner that the primary mixing of the synchronized flow doses of liquid product occurs in the mixing chamber, flow doses from one of the positive shut-off dose stream injectors being directed to collide with the flow doses from the other positive shut-off dose stream injectors.

26. The apparatus for continuous liquid stream digital blending as set forth in claim 25 wherein each of the positive shut-off dose stream injectors is located adjacent to a point of common dosing of the synchronously flowing liquid streams to assure high precision, accuracy and repeatability of mass dose, and prevents any back flow or mixing of other liquid constituents into the individual dose streams.

27. The apparatus for continuous liquid stream digital blending as set forth in claim 24 wherein each dose stream delivery assembly consists of a servo drive motor and associated controller, and a rotary pump.

28. The apparatus for continuous liquid stream digital blending as set forth in claim 27 further characterized by the provision of a servo drive motor mounted digital encoder, and wherein the rate at which each dose flows through the flow meter and is delivered from each positive shut-off dose stream injector is regulated to prevent variance during the period of dosing by digital encoder feedback signal connected directly to the controller associated with the servo drive motor.

29. The apparatus for continuous liquid stream digital blending as set forth in claim 24 wherein the dose stream delivery assembly is a positive displacement pump.

30. The apparatus for continuous liquid stream digital blending as set forth in claim 29 wherein each of the positive displacement pumps is located downstream of an associated bulk supply source and upstream of an associated flow meter.

31. The apparatus for continuous liquid stream digital blending as set forth in claim 24 in which the dose stream delivery assembly associated with each bulk supply source establishes a fixed and constant pressure head at the bulk supply sources, the pressure head delivering liquid product through the respective flow meters to the associated dose stream injectors and thereby into the mixing chamber.

32. The apparatus for continuous liquid stream digital blending as set forth in claim 31, wherein the dose stream delivery assembly includes a constant level reservoir for establishing a fixed and constant pressure head.

33. The apparatus for continuous liquid stream digital blending as set forth in claim 31, wherein the dose stream delivery assembly includes a constant pressure reservoir for establishing a fixed and constant pressure head.

34. The apparatus for liquid stream digital blending as set forth in claim 24 in which a separate positive shut-off dose stream nozzle is mounted downstream of each dose stream delivery assembly and upstream of the mixing chamber in order to permit actual dose sampling capability on each flow stream, thus allowing direct empirical calibration and verification of each flow meter dose ratio.

35. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein two or more ribbon type in-line static mixing devices are provided downstream of the mixing chamber, the ribbon type in-line mixing devices being parallel to each other to reduce system back pressure.

36. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein each flow meter is a volumetric flow meter, the volumetric flow meter serving only as a volumetric flow totalizer and not as a flow rate feedback device and in which the volumetric flow total is determined by a variable frequency digital output from the volumetric flow meter.

37. The apparatus for liquid stream digital blending as set forth in claim 19 wherein the mixing chamber is a kinetic mixing chamber, the synchronized flow doses being combined in the kinetic mixing chamber.

38. The apparatus for continuous stream digital blending as set forth in claim 19 in which parallel flow meters and dose stream delivery assemblies may be provided for one or more liquid products, thus permitting higher total flow rates of the final blended stream without the use of larger flow pathway components.

39. The apparatus for continuous liquid stream digital blending as set forth in claim 19 in which each unit dosing stream apparatus consisting of a bulk supply source, a flow meter, and a dose stream delivery assembly is modular, and wherein a series of units are provided, with overlapping flow capabilities, to provide a range of mass ratio capabilities suitable for use with a broad range of liquids products formulas.

40. The apparatus for continuous liquid stream digital blending as set forth in claim 19 in which the final blend container is a separate and discrete tank.

41. The apparatus for continuous liquid stream digital blending as set forth in claim 40 in which digital flow into the final blend tank is started and stopped by a suitable liquid level control associated with the final blend tank such that blended product is always available from the tank on a continuous flow stream basis up to a specified maximum outflow rate;

and in which adequate final blend tank capacity is available to allow completion of an entire summed digital dose from the mixing apparatus above the maximum tank liquid level established by the liquid level control; and

in which continuous stream final blend tank capacity can be as small as two summed and blended digital doses; and

in which the final blend tank can be enlarged as desired in order to increase final blended product capacity and thus extend depletion time as may be required.

42. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein the dose stream delivery assembly includes a controller for synchronizing the small flow doses, wherein there is an off time between the delivery time of the small flow doses which are delivered to the mixing chamber, and wherein the controller automatically adapts to changes in the continuous stream take-away flow rate from the final blend container by varying the off time interval between synchronous doses, thus eliminating adjustment or re-calibration of the flow streams as a function of varying take away demand.

43. The apparatus for continuous liquid stream digital blending as set forth in claim 19 wherein the final blend container is a discrete and separate unit of use container, the synchronized and mixed doses being filled directly into the unit of use container downstream of the mixing chamber.

44. The apparatus for liquid stream digital blending as set forth in claim 43 in which the unit of use container is a consumer container such as a bottle.

45. Apparatus for continuous liquid stream digital blending comprising:

two or more bulk supply sources of liquid products to be blended;

a mixing chamber downstream of each bulk supply, the mixing chamber having a discharge;

a positive shut-off dose stream injector connected to the mixing chamber;

a final blend container connected to the discharge of the mixing chamber; and

a dose stream delivery assembly downstream of each liquid bulk supply for delivering small flow doses of liquid product from the associated bulk supply source to the mixing chamber, each of the delivery assemblies including a servo motor controlled rotary positive displacement pump directly delivering doses of liquid to the positive shut-off injector nozzle and into the mixing chamber, each dose being derived by the incremental rotation of the rotary positive displacement pump as measured and controlled by a rotary encoder associated with each servo motor, the dose stream delivery assemblies for the two or more bulk supply sources being synchronized to create repeated synchronized flow doses of two or more liquids to the mixing chamber, the string of synchronized intermittent dose cycles creating a desired net flow rate of ratio blended liquids.