This invention relates generally to liquid blending and, more particularly, to a liquid blending system that provides precisely controlled dispensing of the liquid components to attain a blended liquid having desired characteristics.
In fluid blending systems, such as are used in the food and beverage industry, it has been known to route the flow of each liquid component through a mass flow meter in order to blend the components together in a desired ratio. The ratio of the final, blended product is then tested in an out-of-line sampling process at a location far downstream of the location at which the blending operation takes place. While a system such as this is functional, it is subject to error and waste. For example, if the ratio of the final, blended product is outside of specifications, this will not be discovered until a significant amount of blended product has been produced, and all of the out-of-specification product must then be discarded.
Additionally, conventional blending systems, especially those used to blend syrup and water, typically have a storage tank that holds chilled carbonated mixed fluid for subsequent delivery to a filler system that fills individual containers with the mixed fluid. The addition of the storage tank greatly increases the overall size of the blending system and the storage tank must be regularly cleaned. Thus, a blending system setup without such a holding tank would be advantageously smaller, would reduce product inventory and would require less sanitation time.
The present invention involves the use of dispensing equipment that can carefully and precisely control dispensing of the liquid components, in combination with a flow meter that ascertains certain characteristics of the blended product immediately after the liquid components are blended together. In one embodiment, the invention is incorporated into a holding tank-less blending system used to mix syrup and water.
In accordance with one aspect of the invention, a blending system includes a first liquid supply arrangement for providing a first liquid component, a second liquid supply arrangement for providing a second liquid component, a mixing arrangement for mixing the first and the second liquid components to form a blending liquid, and a mass flow measuring device for determining the mass flow of the blended liquid at a location downstream of the mixing arrangement. The blending system further includes a control arrangement for controlling the first and the second liquid supply arrangements in response to the mass flow measuring device.
In accordance with another aspect of the invention, a blending system includes a first liquid supply arrangement for providing a first liquid component, a first volumetric flow determining device for determining the volumetric flow of the first liquid component, a second liquid supply arrangement for providing a second liquid component, and a second volumetric flow determining device for determining the volumetric flow of the second liquid component. The blending system further includes a mixing arrangement for mixing the first and the second liquid components, a density measuring device for measuring the density of the mixed liquid at a location downstream of the mixing arrangement, and a control arrangement for controlling the first and the second liquid supply arrangements in response to the density measuring device.
According to another aspect of the invention, a blending system is provided having first and second liquid supply arrangements that provide first and second liquid components, respectively. The blending system also has mixing arrangement for mixing the first and the second liquid components to form a mixed or blending liquid. A density measuring device is provided for determining the density of the blending liquid at a location downstream of the mixing arrangement, and a control arrangement is provided for controlling the first and the second liquid supply arrangements in response to the density measuring device.
Other objects, features, aspects, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout.
In the drawings:
From source A, the first liquid component is supplied through a line 12a to a metering pump 14a, which is driven by a motor 16a. Similarly, the second liquid component is supplied through a line 12b to a metering pump 14b, which is driven by a motor 16b. The metering pumps 14a, 14b function to accurately dispense desired quantities of the first and second liquid components according to a predetermined ratio. Representatively, the metering pumps 14a, 14b may be progressive cavity metering pumps, such as are available from any number of known manufacturers. The motors 16a, 16b that drive respective metering pumps 14a, 14b are preferably variable speed motors, e.g. servo-type motors. In a manner as is known, motors of this type can be carefully controlled so that the speed of operation can be constantly and almost instantaneously changed as desired, in response to input signals provided by a motor controller. In this manner, the operation of the metering pumps 14a, 14b can likewise be carefully controlled so that the output of each pump can be constantly and almost instantaneously varied as desired.
Metering pump 14a discharges to a line 18a, and metering pump 14b discharges to a line 18b. The lines 18a and 18b connect together, so that the two liquid components are supplied to a line 20. A mixer 22 is in line 20, and functions to mix or blend the two liquid components together as the liquid components are moved through line 20. The mixed or blended liquid then passes through a mass flow meter 24 that is in line 20 downstream of mixer 22. In a manner as is known, the mass flow meter 24 may be a coriolis-type flow meter.
With the configuration as shown in
The coriolis-type mass flow meter 24 functions to measure the volumetric flow, mass flow and density of the mixed or blended liquid. The flow volume is known from the output of the pumps 14a and 14b, and the density of the mixed or blended liquid can be determined using the mass flow meter data. Many typical applications require that the liquid density fall within an acceptable range, and the present invention allows precise and nearly instantaneous control of this important parameter.
In the representative system shown in
As also shown in
As in the system shown in
From source A, the first liquid component is supplied through a line 12a to a pump 40a, which may be any satisfactory conventional pump such as a centrifugal pump, positive displacement pump, etc. A flow meter 42a is located downstream of pump 40a, and a flow meter 42b is located downstream of pump 40b. Flow meters 42a and 42b function to accurately measure the output of respective pumps 40a, 40b at a location immediately adjacent the outlet of each pump. In this manner, the flow rates of liquids A and B can be carefully controlled before the liquids A and B are mixed together. As in the embodiment of
It is understood that the coriolis-type flow meter 24 as shown and described is a mass flow meter, which determines volumetric flow, mass flow as well as density. It is also contemplated that the present invention may be carried out using separate meters that measure flow and density.
While the present invention has been shown and described in connection with the measurement of mass flow and density for compliance with a desired ratio, it is also contemplated that any other parameter of the mixed product can be measured for compliance and that the supply of the liquid components can then be adjusted according to the measured parameter. For example, it is contemplated that parameters such as the color, pH, light absorption, light reflectivity, etc. of the mixed product may be measured and that the supply streams can be adjusted according to such measurements. It is understood that these parameters or characteristics are illustrative of those that can be used to measure compliance with specifications or desired ratios, and that other parameters or characteristics may also be used.
It can thus be appreciated that the controlled liquid blending system of the present invention provides a number of advantages over prior art systems. For instance, the present invention contemplates use of a single coriolis flow meter which measures the volumetric flow, mass flow and density of the blended liquid as opposed to measuring the mass flow of the individual liquid components or streams. In addition, the present invention provides accurate measurement of the concentration of the blended product itself at a location immediately downstream of the point at which the liquid components or streams are mixed. This is in contrast to prior art systems, which involve measurement of the mass flow of the individual liquid components or streams, and then project the concentration of the mixed liquid based on the mass flow measurements of the individual streams or components. The present invention also enables the mixed product to be pressurized in line, which can result in elimination of the pressurized product holding tank utilized in the prior art. Furthermore, the present invention enables the individual liquid components, and therefore the blended liquid stream, to be processed at a variable flow rate, rather than the full production flow rate provided by prior art systems. Importantly, the present invention also allows the production of a multi-component liquid product without the use of a holding or mixing tank. The components of the final product are accurately metered and are mixed immediately downstream of the location at which the final component is introduced, and are then immediately measured to ensure the product is within specifications. If adjustments in the supply streams are required, the adjustments are made immediately and there is little product that is produced before the product is brought back into compliance with specifications.
In addition, it should be understood that the system of the present invention is not limited to use in connection with blending of two liquid streams as shown and described. In fact, the system of the present invention may be used in connection with blending of any number of liquid streams, and the measurement of characteristics of the blended streams downstream of the location at which the individual component streams are mixed may be used to provide accurate and quick adjustments in the flow of the individual streams.
Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.
The present application claims the benefit of U.S. Ser. No. 61/086,360, filed Aug. 5, 2008.
Number | Date | Country | |
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61086360 | Aug 2008 | US |