Patent Application
20170232411
Field of the Invention
The present disclosure is directed to mixing multiple ingredients to form a mixture, more specifically to determining whether the mixture has achieved a desired consistency based on feedback received during the mixing process.
Description of Related Art
Mixing is the process of combining different ingredients to produce a target mixture. While there are many types of mixing processes, all mixing processes can generally be categorized as either batch mixing or continuous mixing. In a batch mixing operation, all ingredients are loaded into a mixer together (or in a pre-defined sequence) and mixed until a homogenous product is produced and discharged from the mixer in a single lot. In a continuous mixing operation, ingredients are continuously loaded into a charging port of a mixer according to a formulation, the ingredients are mixed as they travel from the charging port to a discharge nozzle, and the combined mixture is discharged from the discharge nozzle.
To determine whether a mixture has achieved a desired consistency, the mixture (or a portion of the mixture) may be tested. For example, a viscometer may be used to determine whether a portion of the mixture has achieved a target viscosity. In another example, a rheometer may be used to determine how a portion of the mixture flows in response to applied forces. In a simpler example, a person making a frozen margarita may stir or touch or taste the margarita to see if the ice has been sufficiently blended.
In many instances, it is desirable to automate a mixing process. For example, automating an industrial mixing process may increase the uniformity of an industrial product and reduce cost. In another example, automating a frozen cocktail process may allow a bartender to perform other tasks while a blender prepares the drink.
A mixing process may be automated by mixing the same ingredients for the same time period. The consistency of each mixture may not be uniform, however, because of inconsistency in the ingredients, changes to the mixing apparatus over time, changes in atmospheric conditions, etc.
In order to produce mixtures with the desired consistency, it is desirable to determine the consistency of a mixture. If the consistency of the mixture can be determined during the mixing process, a determination can be made that the mixing process (or a phase in a multi-part mixing process) is complete. If the consistency of the mixture can be determined without the need to test the mixture (or a portion of the mixture), then the decision that the mixing process is complete can be automated.
Accordingly, there is a need to determine the consistency of a mixture during a mixing process without testing the mixture (or a portion of the mixture).
In a separate field of endeavor, U.S. Pat. No. 7,091,683 teaches a method of controlling a motor used to drive a screwdriver bit such that screws are seated to the optimum point of grip between the screw and the work piece material independent of the material density.
According to an exemplary embodiment of the present invention, there is provided a mixer, including an impeller that agitates the ingredients to form the mixture, a motor shaft that rotates the impeller, a motor that exerts torque on the motor shaft to rotate the motor shaft, a feedback device that outputs feedback, and a controller that determines a consistency of the mixture based on the feedback.
According to another exemplary embodiment of the present invention, there is provided a method of mixing ingredients to form a mixture by exerting torque on a motor shaft to rotate the motor shaft and an impeller, outputting feedback to a controller, and determining a consistency of the mixture based on the feedback.
The feedback may be indicative of the torque exerted on the motor shaft. The consistency of the mixture may be determined based on the amount of torque (or rate of change of torque or change in the rate of change of torque) required to rotate the motor shaft at an angular velocity. The controller may determine whether the mixture has achieved a desired consistency by comparing the torque information to a stored torque profile indicative of the relationship between the angular velocity of the motor shaft and the torque required to rotate the motor shaft at the angular velocity. The torque information may be determined based on the current in the coils of the motor (e.g., by measuring the voltage across a precision resistor in series with the coils of the motor).
Alternatively, the feedback may be indicative of the angular velocity of the motor shaft, sound output by the mixer, vibration of the mixer, a color of the mixture, or opacity of the mixture.
Preferred embodiments of the present invention will be set forth with reference to the drawings, in which:
Preferred embodiments will be set forth in detail with reference to the drawings, in which like reference numerals refer to like elements or steps throughout.
As shown in
In one embodiment, the mixer 200 may determine the consistency of the mixture during the mixing process based on the relationship between the angular velocity of the motor shaft 162 and the torque required to rotate the motor shaft 162. The relationship between the torque required to rotate the motor shaft 162 and the angular velocity of the motor shaft is referred to as a “torque profile” (or “torque fingerprint”).
As illustrated in
Each time the mixer 200 is used to mix the same ingredients, the relationship between the angular velocity ω and the torque τ follows a similar pattern (such as the pattern illustrated in
Accordingly, the mixer 200 may determine the consistency of the mixture based on the relationship between the angular velocity of the motor shaft 162 and the torque required to achieve the angular velocity ω of the motor shaft 162. In one embodiment, the mixer 200 may determine the consistency of the mixture based on the amount of torque required to achieve the angular velocity ω of the motor shaft 162. In another embodiment, the mixer 200 may determine the consistency of the mixture based on the rate of change of torque. In another embodiment, the mixer 200 may determine the consistency of the mixture based on a change in the rate of change of torque (for example, if the mixer 200 transitions from requiring an increasing amount of torque to maintain an angular velocity ω of the motor shaft 162 to requiring a constant amount of torque to maintain the angular velocity ω of the motor shaft 162, or if the mixer 200 transitions from requiring a constant amount of torque to maintain an angular velocity ω of the motor shaft 162 to requiring a decreasing amount of torque to maintain the angular velocity ω of the motor shaft 162, etc.)
In another embodiment, the mixer 200 may determine whether the mixture has achieved the target consistency as the mixing process follows the torque profile. As illustrated in
Referring back to
If the motor 160 is an electrical motor, the torque exerted on the motor shaft 162 by the motor 160 is proportional to the amount of electrical current flowing through the coils of the motor 160. The electrical current may be measured as voltage produced across a resister that is in series with the coils of the motor 160 as described in U.S. Pat. No. 7,091,683. Accordingly, in one embodiment, the motor 160 may include a precision resistor in series with the motor coils and the feedback device 220 by determining the torque exerted on the motor shaft 162 by the motor 160 based on the voltage across the precision resistor.
While the torque output by the motor will generally follow the torque profile, the amount of torque will also have peaks and/or valleys (for example, if the impeller 160 makes contact with solids in the mixture). Accordingly, the mixer 200 may include a smoothing circuit that averages the voltage across the precision resistor over time so as to remove the peaks and/or valleys from the torque signal. For example, the feedback device 220 may include an analog smoothing circuit (e.g., a capacitor with resistors and/or a diode). Additionally or alternatively, the controller 240 may digitally smooth the analog signal output by the feedback device 220.
The feedback device 220 may also output information indicative of the angular velocity of the motor shaft 162 to the controller 240. In order to determine the angular velocity, the feedback device 220 may include an encoder, a Hall Effect sensor, a back EMF sensor, etc.
Ingredients are added to the mixer 200 in step 404. The motor 160 rotates the impeller 140 in step 406. The motor 160 may rotate the impeller 140 at a known, constant angular velocity or following a known pattern. The feedback device 220 measures the torque and outputs information indicative of the torque measurement in step 408. The controller 240 determines the consistency of the mixture in step 410. As described above, the controller 240 may determine the consistency of the mixture based on the amount of torque, the rate of change of torque, etc. In step 412, the controller 240 determines whether the mixture has achieved a target consistency. If the mixture has yet to achieve the target consistency (step 412: No), the process returns to step 406 and the mixer continues to rotate the impeller 140 and mix the ingredients.
If the controller 240 determines that the mixture has achieved the target consistency, the mixer 240 performs a function in step 414. In one example, the controller 240 may stop the mixing process in step 414. In another example, the mixer 200 may output an indication to another system or a human operator that the mixture has achieved the target consistency in step 414. In another example, the mixer 200 may be configured to add an additional ingredient to the mixing container 120 in step 414 (or output an indication to another system or a human operator to add an additional ingredient to the mixing container 120). The additional ingredient may be a new ingredient or an additional quantity of an ingredient that has already been mixed. In a continuous mixing process, for example, additional solvent may be added if the controller 240 determines based on the torque that a portion of the solvent in the mixture has evaporated. In another example, the controller 240 may change the torque output by the motor 160, the rate of change of the torque output by the motor 160, the angular velocity of the motor shaft 162, the rate of change of the angular velocity of the motor shaft 162, etc.
The mixing process 400b includes many of the same steps as the mixing process 400b. The mixing process 400b includes the additional step of storing a torque profile in step 402. In step 406, the motor 160 rotates the impeller 140 at the angular velocity indicated in the torque profile. In steps 410 and 412, the controller 240 determines whether the mixture has achieved a target consistency based on a comparison of the torque information received from the feedback device 220 and the torque profile.
The mixer 200 may be used to create the torque profile. For example, a user may mix ingredients in the mixer 200. The feedback device 200 may output torque information and angular velocity information to the controller 240 as described above. The mixer 200 may allow the user to indicate when the mixture has achieved the desired consistency. The controller 240 may store a torque profile in the memory 244. The torque profile may include the torque information received from the feedback device 220, the angular velocity information received from the feedback device 220, and the point at which the mixture achieved the desired consistency.
The torque profile illustrated in
First, the relationship between the torque and the angular velocity will differ based on the ingredients (for example, the torque required to maintain a constant angular velocity may increase due to evaporation of solvents).
Second, the mixer 200 may be configured such that the angular velocity ω of the motor shaft 162 exhibits any desired pattern. As long as the motor shaft follows the same angular velocity ω pattern as stored in the torque profile, the controller 160 may determine the consistency of the mixture based on the torque τ.
Third, the controller 240 may not store a torque profile that encompasses all phases of the mixing process. For example, the torque profile stored in memory 244 may only illustrate the relationship between the torque τ and a constant angular velocity ω as shown in phase 3. In that example, the mixer 200 first accelerates the motor shaft 162 to a constant angular velocity ω before determining the consistency of the mixture based on the torque τ.
As described above, the relationship between the torque τ output by the motor 160 and the angular velocity ω of the motor shaft 162 depends on the consistency of the mixture. Accordingly, as one of ordinary skill in the art will recognize, the mixer 200 may be configured such that the motor 160 outputs torque τ following a known pattern and determines the consistency of the mixture based on the resulting angular velocity ω of the motor shaft 162, a rate of change of the angular velocity ω, a change in the rate of change of the angular velocity ω, and/or comparison between the angular velocity and an angular velocity profile (similar to the torque profile illustrated in
Using the same principles discussed above, the mixer 200 may determine the consistency of the mixture based on other types of feedback. For example, the sound and/or vibration output by the mixer 200 may follow a consistent pattern during the mixing process. Accordingly, feedback device 220 may measure the sound output by the mixer 200 (for example, using a microphone) or determine the vibration of the mixer 200 (for example, using an accelerometer or other vibration sensor) and output information indicative of the sound/vibration to the controller 240, which may determine whether the mixture has achieved the target consistency based on the sound/vibration information. In one example, the controller 240 may determine the consistency of the mixture based on the amount of sound/vibration. Additionally or alternatively, the controller 240 may determine the consistency of the mixture based on the rate of change of the sound/vibration. Additionally or alternatively, the controller 240 may determine the consistency of the mixture based on a change in the rate of change of the sound/vibration. Additionally or alternatively, the controller 240 may store a sound and/or vibration profile (similar to the torque profile illustrated in
To cite just one example of a mixer 200 that may use sound or vibration to control a mixing process, a garbage disposal that mixes solids with water and grounds the mixture may automatically shut off when the sound or vibration output by the garbage disposal indicates that the solids have been disposed of.
In another embodiment, the consistency of the mixture may be determined based on the behavior of light as it passes through and/or reflects off of the mixture. In this embodiment, the feedback device 220 may include an optical emitter that emits light through and/or off the mixture and an optical sensor that receives the light after. The optical sensor may output information indicative of the light to the controller 240, which may determine the consistency of the mixture based on the signal output by the optical sensor. For example, the controller 240 may determine the consistency of the mixture based on the opacity and/or color of the mixture. Additionally or alternatively, the controller 240 may determine the consistency of the mixture based on a change in the opacity and/or color of the mixture. Additionally or alternatively, the controller 240 may store a light profile (similar to the torque profile illustrated in
Determining the consistency of the mixture based on feedback (e.g., torque, velocity, sound, vibration, light, etc.) received during the mixing process provides a number of benefits. First, the consistency of the mixture can be accurately controlled to produce repeatable results. Additionally, the mixing process may be automated to reduce cost. Finally, because the mixing process may stop when the mixture has achieved the desired consistency, efficiency may be increased while processing time, cost, and wear and tear on the mixer 200 may be reduced.
The mixer 200 may be any device configured to agitate any number of ingredients, such as a ribbon blender, a paddle blender, vertical screw blender, a sigma mixer, a planetary mixer, a plow mixer, a double paddle mixer, a Forberg mixer, etc.
The mixer 200 may be configured to allow a user to select a desired consistency (for example, via an operator panel, a wireless connection to a smartphone or personal computer, and/or another input device). The mixer 200 may also be configured to determine and store the consistency of a mixture in the memory 224 and to use the stored consistency as the target consistency during a subsequent mixing process.
The impeller 140 may be an axial flow impeller with blades 142 that make an angle of less than 90 degrees from the plane of impeller rotation (e.g., marine propellers, pitched blade turbines, etc.), a radial flow impeller with blades 142 that are parallel to the axis of the impeller 140 (e.g., flat blade turbines, paddles, etc.), etc.
The mixing process may be industrial, commercial, personal, etc. The term “mixing” may to refer to any process of combining any number of ingredients. In one embodiment, the ingredients being mixed may be different. In another embodiment, chemically homogenous material may be mixed to produce a uniform lot with consistent particle size distribution, color, texture, and/or other attributes. The ingredients may in be any fundamental state (i.e., solid, liquid, gas, plasma), may be a combination of multiple fundamental states, and/or may transition from one fundamental state to another during the mixing process.
The terms “mixing” and “blending” are often used interchangeably, but are sometimes used to describe different processes. Blending may be used to describe solid-solid mixing or mixing of bulk solids with a small quantity of liquid, while mixing may be used to describe liquid-liquid mixing, gas-liquid mixing, and viscous material mixing. The term “mixing” is used throughout this application to refer to both mixing and blending.
As used herein, the consistency of a mixture may refer to any characteristic of the mixture that affects the way the mixture holds together such as thickness, density, viscosity, heaviness, texture, firmness, solidity, evenness, uniformity, regularity, stability, equilibrium, etc.
In addition to the mixing processes described above, similar feedback may be used in conjunction with other pumping processes. For example, a gas supply line may be monitored using a vibration sensor to detect the vibration caused when the gas is flowing through a supply line. The microprocessor can be programmed to distinguish between normal gas usage and a leak. The system can be integrated with sensors on devices that normally or periodically call for gas and learn which patterns are normal. If the gas flow is determined to be abnormal, indicating a leak, the microprocessor can close the gas valve automatically. Additionally an audible signal, wireless signal to a smart phone or PC could be produced. This can reduce the risk of fire or explosion on the premises.
In another example, toilet water supply can be monitored/controlled by placing a vibration sensor on the toilet to detect the vibration caused when the valve is open allowing water into the tank. If the water flows for greater than a programmed time period, the microprocessor can close a valve which supplies water to the tank. This would reduce water waste and the risk of flooding the premises. Additionally an audible signal or wireless signal to a smart phone could be produced.
In another example, water supply to a premises can be monitored and controlled by placing a vibration sensor on the water supply to detect the vibration caused when the water is flowing through a supply pipe. If the water flows for greater than a programmed time period, the microprocessor can close a valve that supplies water to the premises. This would reduce water waste and the risk of flooding the premises. Additionally an audible signal or wireless signal to a smart phone could be produced.
While preferred embodiments have been set forth in detail, it will be appreciated that other embodiments can be realized within the scope of the invention. The present invention should be construed as limited only by the appended claims.
This application claims priority to U.S. Prov. Pat. Appl. No. 62/074,184, filed Nov. 3, 2014, the entire contents of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2015/058858 | 11/3/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62074184 | Nov 2014 | US |
