Lime tolerant brewing system and method

Disclosed is a system and method of dispensing a selected volume of liquid. The system includes an apparatus that has a reservoir having an inlet tube and outlet tube coupled thereto, and a controller for controlling at least a portion of the apparatus. Two level sensors are positioned along the reservoir and are in communication with and controlled by the controller. The method includes steps for measuring a time a liquid level in the reservoir falls from an upper level to a lower level to calculate a flow rate. The calculation flow rate may then be used to determine and compare a dispensed volume versus the selected volume. Dispensing may then continue until the selected volume has been dispensed.

BACKGROUND

The present disclosure is related to system for dispensing a selected volume of liquid. In particular, the present disclosure is related to a system for dispensing a selected volume of liquid for use in brewing a beverage, such as, for example, coffee.

Current beverage making apparatuses employ a variety of techniques to control the volume of liquid dispensed during a beverage making process. It is desirable to have a preselected volume of beverage dispensed to prevent “short potting,” a condition where less than the intended volume of beverage is dispensed. As an example, but not by way of limitation, during the production of coffee, a short pot would mean that an insufficient volume of water would be combined with coffee grounds, resulting in a coffee beverage having a resulting flavor, extraction or other characteristics, that are different than intended, and thus not having the desired taste or meeting other criteria.

Briefly, and in accordance with the foregoing, disclosed is a system and method of dispensing a selected volume of liquid. The system includes an apparatus that has a reservoir having an inlet tube and outlet tube coupled thereto, and a controller for controlling at least a portion of the apparatus. Two level sensors are positioned along the reservoir and are in communication with and controlled by the controller. The method includes steps for measuring a time a liquid level in the reservoir falls from an upper level to a lower level to calculate a flow rate. The calculation flow rate may then be used to determine and compare a dispensed volume versus the selected volume. Dispensing may then continue until the selected volume has been dispensed. While the method and apparatus is shown and describes for use with beverage dispensing, this is provided by way of illustration and not limitation.

Additional features and embodiments will become apparent to those skilled in the art upon consideration of the following detailed description of drawings.

The exemplification set out herein illustrates embodiments of the disclosure that is not to be construed as limiting the scope of the disclosure in any manner.

DETAILED DESCRIPTION

While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure and is not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings.

The present disclosure provides an apparatus, system, and method for controlled dispensing of liquid which may be used with a beverage maker or beverage brewer. Terms including beverage, brewed, brewing, brewing substance, beverage preparation material, brewed liquid, and brewed beverage as may be used herein are intended to be broadly defined as including, but not limited to, the brewing of coffee, tea and any other beverages. This broad interpretation is also intended to include, but is not limited to any process of dispensing, infusing, steeping, reconstituting, diluting, dissolving, saturating or passing a liquid through or otherwise mixing or combining a beverage substance with a liquid such as water without limitation to the temperature of such liquid unless specified. This broad interpretation is also intended to include, but is not limited to, beverage substances such as ground coffee, tea, liquid beverage concentrate, powdered beverage concentrate, flaked, granular, freeze dried or other forms of materials including liquid, gel, crystal or other forms of beverage or food materials to obtain a desired beverage or other food product.

As shown inFIG. 1, an apparatus8for dispensing liquid9includes a controller10coupled to various components or controllable devices associated with an inlet liquid or water delivery assembly, which may include a liquid reservoir12and which controls or receives information from at least a portion of a beverage maker that is associated with the apparatus8. When apparatus8is used in beverage machines that produce a heated beverage, such as coffee, tea, or soup, liquid reservoir12may include a heater, such as heating element13associated therewith to heat the liquid to a predetermined temperature or within a range of temperatures. Such a heating element13is coupled to and controlled by controller10. Alternatively, for ambient temperature liquid dispensing apparatuses, the heating element13is not activated or no heating element may be needed. The present disclosure may also be used for cooled liquid dispensing in which case a cooling element or system would be used instead of a heating element. An inlet tube14is coupled to and communicates with liquid reservoir12for dispensing liquid into liquid reservoir12. An inlet valve15is coupled with or otherwise positioned along inlet tube14. Inlet valve15may be coupled to controller10for controllably permitting or restricting flow when the particular application may so require, or may be operated independently of controller10.

Associated with reservoir12is a first level sensor18, coupled to controller10, and positioned at a first level16above a bottom23of reservoir12which senses whether liquid in reservoir12reaches the first level16. A second level sensor19, coupled to controller10, and positioned at a second level17above bottom23which senses whether liquid in reservoir12reaches second level17. Second level17is below level first level16. Any suitable level sensor may be used including a conductance based level sensor positioned within the interior of reservoir12, a capacitive level sensor, sonic level sensor, optical level sensor or weight driven level sensor associated with reservoir12.

A volume21is defined between levels16,17in reservoir12. Various distances between level sensors18and19may be used to select volume21, such as, by way of example but not limitation, 0.2 inches. Volume21would thus be calculated by multiplying the distance between levels16and17by a square of the radius of reservoir12by pi. Other embodiments in which reservoir12is not cylindrical may also be used, with volume21being calculated by using the cross-sectional dimensions of the reservoir together with the distance between levels18,19.

Liquid is controllably dispensed from reservoir12via outlet tube22. An outlet valve24is associated with outlet tube22and is coupled to and controllably operated by controller10. When outlet valve24is open, liquid can pass out of outlet tube22. As an example, outlet tube22may lead to a spray head26to be distributed over beverage making material28positioned in a brew funnel30to allow the liquid, for example heated water, to contact the beverage making material, for example ground coffee, to make a desired beverage such as coffee. The brewed beverage is then passed into a container such as a coffee carafe32for distribution and consumption.

Controller10can controllably operate apparatus8to dispense a selected volume of liquid, such as for example, one pot of coffee, or in larger commercial settings, one or more multi-serving beverage containers. One embodiment of a method to dispense a selected volume is shown inFIG. 2. For purposes of convenient illustration and description only, first level16is referenced as L2and second level18is referenced as L1herein.

In a first step40, reservoir12is filled at above L2. A brew cycle is then started42and, in one embodiment in which the liquid is heated, the heating element or heater13is turned off. Heater13may be turned off to prevent a situation where the surface of the liquid stored reservoir12starts to boil, bubble, or otherwise vaporize as the liquid is heated. Such bubbling or vaporization may cause level sensors18,19to erroneously report the liquid has reached those levels. The present method may be used in combination with more accurate level sensors that can account for, ignore, adjust for or cancel the effects of such conditions. However, where less expensive or more readily available level sensors are used, the heater13may be turned off to increase accuracy as described above.

Liquid is dispensed at this point by controllably operating outlet valve24to allow liquid to pass out through outlet tube22. Volume21may be located above outlet tube22to create a head pressure to force liquid out tube22when outlet valve24is opened. The timing of opening outlet valve24in combination with level sensors18,19detecting their respective levels conveniently allows controller10to determine a time T1that it takes a liquid level to drop from L2to L1(step46). This time in combination with determining known volume21allows simple calculation of a flow rate out outlet tube22. That simple calculation may be flow rate equals known volume21divided by T1. At this point, the calculated flow rate may be used to calculate the time outlet valve24need to remain open to dispense the selected volume. Once T1is calculated, inlet valve15is opened to allow reservoir12to refill to continue the brewing cycle.

Steps48through66represent an embodiment of the present method that may be used to account for discrepancies in the flow rate over at least a portion of the brewing cycle. These discrepancies may be caused by a variety of factors including but not limited to, turbulence within the reservoir, a power surge, movement of apparatus8, a momentary inaccurate reading by one or both of the level sensors16,18, and other factors.

To account for such a discrepancy, T1is compared to some previously calculated flow rate to see if the two rates are the same within a tolerance, to deem the calculated flow rate stable and thus reliable for timing calculations. In a step48, for example, if T1is within 2% of a previous measured or calibrated time Tp, T1is used (step50). If T1is not within the selected tolerance, a second time T2, is measured (step52). If T2is within a selected tolerance, such as for example is 2% (step54) of Tp or 2% of T1(step58), T2is used (step56). The comparison may be made to either of Tp or T1because repeatability or stability is the desired trait of the timing measurements. If T2is not within tolerance with respect to T1or Tp, a third time T3is measured, again as the time the liquid level falls from L2to L1(step60). If T3is within a selected tolerance, such as 5% of T2, T3is used (step64). Otherwise, Tp is used again because Tp apparently is the only stable time (66). The tolerance for the third sub-cycle to measure T3may be less precise than for the previous two readings because stability is being measured over a longer period.

Although three sub-cycles are shown for determining a new Tp, more cycles may be used. However, in an embodiment where the liquid is heated, the heater may not be turned on until all the times have been measured (see step68). As discussed above, having an activated heater while the level sensors are operating may cause less than optimal readings because of bubbling, vaporization, turbulence, or other factors. Limiting taking L2-L1sub-cycle time measurements to only a subset of the total L2-L1sub-cycles in a particular brewing cycle, allows a stable flow rate to be measured while allowing the heater to be reactivated within a reasonable time to allow the apparatus to be reset for another heating cycle. In one embodiment, between one and three L2-L1sub-cycles are timed out of five total L2-L1sub-cycles needed to dispense a selected volume for one brew cycle.

One embodiment of an initial calibration method is shown inFIG. 3. In a calibration environment, a brewing cycle is started (step80). It is assumed the liquid level in the reservoir12is already at least at L2. In step82, outlet valve24is opened to allow liquid to escape while controller10monitors the amount of time it takes the liquid level in the reservoir to drop from L2to L1. Once the first L2-L1cycle is completed, the inlet valve15is opened to permit refilling of reservoir12. A count of the number of L2-L1cycles, designated hereinafter as N, is kept (step84). The total number of cycles N may include a partial cycle because outlet valve24may close prior to the completion of that last cycle if the selected volume has been dispensed. Therefore the actual number of full cycles may be designated N−1.

An average flow rate Ro may then be calculated as shown in step86, as being equal to (N×QL12)/TL12, where QL12is volume21, and TL12is time it takes the level to fall from L2to L1. Controller10may be programmed to measure a total outlet time to (step88) which is used to calculate the total dispensed volume Qo in the formula shown in step90.

A method for dispensing a selected volume Qo during operation of the apparatus8is shown inFIG. 4. A brew cycle92is started. An initial outlet valve open time, referred to herein as Vo, is calculated using the values calculated during the calibration cycle, such as shown inFIG. 3, or using values from one or more previous brew cycles (step94). An L2-L1sub-cycle is started (step96) with flow rate Ro being recalculated (step98). The series of L2-L1times used to calculate the new flow rate may be selected based on the stability considerations discussed forFIG. 2. The dispensed volume is monitored in step100against the selected dispensed volume (Step102). If Qo has not been dispensed (step104), a remaining Vo on-time, designated herein as TRn, is calculated and another L2-L1sub-cycle is permitted. Otherwise, outlet valve24is shut and the brew cycle is ended (step106).

The remaining valve open time may be recalculated several times over the course of the brew cycle depending on the flow rate calculated for the L2-L1sub-cycles. A formula110is shown inFIG. 5for calculating the remaining Vo on-time after N cycles, where TDx is the time from end of the previous cycle to the end of the current cycle x. A derivation of the formula is shown inFIG. 6A-B, where the bottom of6A continues to the top of6B.

It is envisioned that a software module may be used to retrofit an existing beverage machine to provide for the controlled liquid dispensing described above. The term “module” referenced in this disclosure is meant to be broadly interpreted and broadly cover various types of software code including but not limited to routines, functions, objects, libraries, classes, members, packages, procedures, methods, or lines of code together performing similar functionality to these types of coding. The retrofit may include, but is not limited to, adding a new controller module or component, updating an existing controller with the software module through any available programming method, including flashing a controller's memory, replacing a chip, replacing a circuit board, or copying and running software code on memory accessible to a controller's microprocessor. The software module may be included as part of a retrofit kit for updating an existing dispensing machine to include the functionality describe above. It is also envisioned that kit may be used to retrofit an existing beverage maker that lacks a flow regulator. Thus an alternative version of the kit may include a flow regulator and sufficient components and instructions for connecting it to the inlet line and a software module.

While embodiments have been illustrated and described in the drawings and foregoing description, such illustrations and descriptions are considered to be exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. The applicants have provided description and figures which are intended as illustrations of embodiments of the disclosure, and are not intended to be construed as containing or implying limitation of the disclosure to those embodiments. There are a plurality of advantages of the present disclosure arising from various features set forth in the description. It will be noted that alternative embodiments of the disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the disclosure and associated methods, without undue experimentation, that incorporate one or more of the features of the disclosure and fall within the spirit and scope of the present disclosure and the appended claims.