JP2008530497A - Method and apparatus for detecting and manufacturing ice - Google Patents

Abstract

Methods and apparatus for making and sensing ice are provided. In addition, an apparatus and method for sensing a phase change in a material is provided. In one embodiment, a fringe effect capacitor is placed closest to a substance such as water that undergoes a phase transition, such as a phase change from a liquid state to a solid state. During this change, the dielectric constant of the material changes, thereby changing the electrical flux between the conductors of the fringe effect capacitor. Furthermore, the apparatus and method described above is provided that uses a capacitor that is not a fringe effect capacitor.
[Selection] Figure 22

Description

Cross-reference to related applications

  This application is a priority of US Provisional Patent Application No. 60 / 653,194, filed February 15, 2005, and US Provisional Patent Application No. 60 / 742,730, filed December 6, 2005. Is an insistence. Both provisional patent applications are incorporated herein by reference.

  The present invention relates to improvements in capacitive sensors, including sensors used during ice formation and manufacturing, and further includes an ice making method using any type of sensor, and the formation of frost or ice or other condensate. It relates to a method for detecting.

  The typical operation of an ice machine, whether commercial or personal, is to fill the container with water, remove heat from the water, and drain the ice cube. Including. One method of making an ice cube involves filling a container with multiple compartments and removing heat from all compartments. Another method of manufacturing ice cubes uses an evaporator with a number of fingers with closed ends suspended in a water bath. As the ice making operation proceeds, the refrigerant in the fingers of the evaporator tube cools and freezes the water surrounding each finger, forming gradually increasing walls. The overall shape of the resulting ice cube can be said to be a thimble. Typically, the evaporator cools the water for a period of time sufficient to completely freeze the ice cube. Remove the fully frozen ice cube and start another cycle of the ice machine after removal.

  There is a need for ice makers with shorter cycle times used. Furthermore, there is a need for an apparatus and method for determining ice cube status in real time. Some embodiments of the present invention solve both of these problems in a novel and inventive manner.

One embodiment of the present invention relates to an ice making device that includes means for sensing the capacitance of water and providing a signal corresponding to the capacitance of the water and a controller that operates in response to the signal.
In some embodiments, the controller activates the refrigeration system, senses when the water is partially frozen using the signal, and activates the refrigeration unit to discharge the partially frozen ice cube. To do.

  In some embodiments, the sensing means is a fringe effect capacitor. In another embodiment, the fringe effect capacitor has at least two electrodes and water is the dielectric for these two electrodes.

  In yet another embodiment, the sensing means is a capacitor having at least two electrodes, and the water in the container is the dielectric between these two electrodes. In another embodiment, one electrode of the capacitor is part of the refrigeration unit.

In yet another embodiment, the controller is a digital controller with a memory that contains data relating a predetermined thickness of ice in the container to the capacitance of the water. .
One embodiment of the invention relates to an apparatus for sensing the capacitance of water, including a refrigeration unit. The refrigeration unit includes a conductive first member disposed closest to a position where the substance changes phase by the operation of the refrigeration unit, and a conductive second member disposed closest to the same position. The two members are electrically insulated and spaced from the second member. The refrigeration unit further includes a circuit electrically connected to the first member and the second member, the circuit generating a signal corresponding to the capacitance of the substance.

  In some embodiments, the first member is an evaporator tube. In another embodiment, the first member has a first shape immersed in water and the second member has a second feature corresponding to the first feature immersed in water.

  Another embodiment includes a container for holding water, the refrigeration unit can remove heat from the container, the container has a predetermined shape, and the second member has a predetermined shape corresponding to the shape of the container. Has a shape.

  Another embodiment of the present invention is to obtain a first measurement of the capacitance of the first phase material and change the heat content contained in the material to convert some of the material into the second phase. Detecting a phase transition of the substance, including changing, obtaining a second measured value of the capacitance of the substance having both phases, and comparing the first measured value to the second measured value On how to do.

  In one embodiment of the invention, the comparing includes dividing one of the first measurement value or the second measurement value by the other of the first measurement value or the second measurement value. In another example, the comparing includes subtracting one of the second measurement value or the first measurement value from the other of the second measurement value or the first measurement value.

  Other examples include determining by comparing whether a certain amount of ice has been produced. Yet another embodiment includes stopping removing heat after determining.

  In another embodiment, the method includes a capacitor for obtaining a first measurement value and a second measurement value, wherein at least some of the material that changes phase acts as a dielectric for the capacitor. To do.

  In another embodiment, the first member has a first feature immersed in water and the second member has a second feature corresponding to the first feature. Yet another embodiment includes a container for holding water, the refrigeration unit can remove heat from the container, the container has a predetermined shape, and the second member has a predetermined shape corresponding to the shape of the container. Have

  Another embodiment of the invention relates to an ice making device. The device includes a plurality of containers, each of which has a plurality of sides that define an interior volume. Each container has an opening for introducing water and discharging ice. A fringe effect capacitor whose capacitance is affected by the presence of water is provided on one side of the container.

  In another embodiment, the capacitor is not a fringe effect capacitor but includes at least two capacitive elements and a gap between these elements. The capacitor is so formed that the gap is arranged on one side closest to the center of the volume portion.

  Another embodiment of the invention relates to a capacitor. This embodiment has a substrate that includes first and second opposing sides and a surface therebetween. The embodiment further includes a first electrode attached to a surface closest to the first side, the first electrode having a first finger extending toward the second side, wherein the first finger is It has a variable width. The embodiment further includes a second electrode attached to the surface closest to the second side, the second electrode having a second finger extending toward the first side, the second finger being It has a variable width and is spaced from the first finger by a variable gap.

  In another aspect, an example is provided wherein the surface is a first surface, the substrate has a second surface opposite the first surface, and an electrical shield is provided on the second surface. As yet another aspect, an embodiment is provided wherein the surface is a first surface, the substrate has a second surface opposite the first surface, and the second surface is not electrically shielded.

  It will be understood that the various apparatus and methods described in this and other portions of the application have been described as many different combinations. All these useful, novel and inventive combinations are contemplated herein, and it is redundant to describe each of these myriad combinations in full It is unnecessary.

  These and other features of various embodiments of the invention will be apparent from the claims, the specification, and the accompanying drawings.

  For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the accompanying drawings and specific language will be used to describe the same. Nevertheless, the scope of the present invention is not intended to be limited thereby, and variations and modifications of the illustrated apparatus, as well as other uses of the inventive principles illustrated herein, are contemplated by the technical field of the present invention. It is considered that the person skilled in the art usually comes up with.

  US patent application Ser. No. 10 / 898,842, filed Jul. 26, 2004 and entitled “Anti-Tamper Connector for Engine Radiators”, U.S. Pat. No. 6,311 issued on Nov. 6, 2001. , 503, U.S. Pat. No. 6,438,976 issued on Aug. 27, 2002, U.S. Pat. No. 4,766,369 issued on Aug. 23, 1988, May 29, 2001. US Pat. No. 6,239,601 issued to the US, Vol. 33, No. 12, “Fractal Capacitor” of IEEE Journal of Solid State Circuits published in December 1998, is incorporated herein by reference. In addition, US Pat. No. 6,842,018, granted to Macintosh on January 11, 2005, is incorporated herein by reference. In addition, the patent application filed by the same applicant on February 15, 2006, entitled “Capacitive Rain Sensor”, with case number 31142-38 of representative, is incorporated herein by reference.

  Some embodiments of the invention relate to measuring the progress of ice formation from a fully liquid state to a partially frozen or fully frozen ice cube. In some embodiments, this measurement can be used to increase the ice making rate. In such an embodiment, the ice cube is removed even though the center of the ice cube is not frozen and is still liquid. A partially frozen ice cube can be drained and maintain its structural integrity if the wall is sufficiently thick. By placing the partially frozen ice cube in a bin below the freezing temperature, the coagulation process is continued and completed in the bin. However, when solidification of the first ice cube is in progress, the liquid container can be returned to the beginning of the process and refilled with liquid water to initiate the formation of the second ice cube. In such an embodiment, the time required for freezing the first and second sets of ice cubes overlaps, thus increasing the ice making speed as a whole.

  Some embodiments of the present invention include a method of detecting ice formation using capacitive techniques, preferably placing a sensor electrode near a water sample. Preferably, the water sample is placed close enough to the electrode so that the dielectric constant of the water affects the capacitance of the sensor. Liquid water has a dielectric constant of about 80, whereas ice has a dielectric constant of about 3. In some embodiments of the present invention, the sensor is adapted to change capacitance in response to changes in the amount of liquid water and the change in ice thickness closest to the sensor electrode. Is formed. This 26 rate of change in capacitance can be measured in a number of ways, including a 4-arm bridge circuit.

  In some embodiments, the operating principle of the capacitor corresponds to that of a lateral flux capacitor, or fringe-effect capacitor. In some embodiments, the electrodes are arranged laterally with respect to each other on the substrate as opposed to parallel plate capacitors (eg, as shown in US Pat. No. 4,766,369). is there.

  As described in US Pat. No. 4,766,369 and US Pat. No. 6,239,601, smaller electrode widths and smaller electrode gaps can be used to detect thinner ice layers. Good. In addition, larger electrodes with larger gaps may be used to detect thicker ice layers. The smaller pattern responds quickly to a thin ice layer, but this pattern reaches a predetermined point where there is little change in power with increasing thickness. For larger patterns, this is less responsive to smaller ice thicknesses, but can respond to thicker layers that are no longer detectable with smaller patterns. The width of the intermediate electrode separated by the intermediate gap then responds to the medium thickness ice layer. Although the width and spacing of the electrodes can be varied separately, they can also be varied continuously. Some embodiments of the present invention provide a sensor that can continuously respond to ice thickness.

  One embodiment of the present invention relates to a fringe effect capacitor having a variable electrode width and a variable electrode gap, that is, a combination of a variable gap and a variable width. In one embodiment, the width of the electrode varies smoothly along the length of the electrode. In another embodiment, the gap between the electrodes varies smoothly along the length of the electrodes. In yet another embodiment, both the gap between the electrodes and the width of the electrodes vary linearly across the sensor substrate. In a preferred embodiment, the gap between the electrodes is small when the electrode width is small and large when the electrode width is large.

  In one embodiment, the sensor includes a plurality of fingers of opposite polarity combined with each other. The width of the fingers and the gap between adjacent fingers varies linearly along the surface of the sensor substrate. However, the present invention is not limited to such a linear relationship. In another embodiment, each electrode includes one or more fingers attached in a spiral pattern to the surface of the substrate. In yet another embodiment, the electrodes are arranged in a circular pattern.

  Preferably, the width of the electrodes corresponds to the gap between adjacent electrodes, wide electrodes are separated by large gaps, and narrow electrodes are separated by narrow gaps. In one example, the electrode width and the gap between adjacent electrodes vary very smoothly along the length of the electrode. However, the present invention provides an embodiment in which the gap between adjacent electrodes varies separately (stepwise) along the length of the electrode, and the width of the electrode separately (stepwise) along the length of the electrode. ) We also consider changing embodiments.

  FIG. 1 illustrates an ice sensor 20 according to one embodiment of the present invention. The sensor 20 includes a first electrode 22 and a second electrode 24 disposed on the surface 28 of the substrate 26. The first electrode 22 includes a plurality of first fingers 34 extending on the surface 28 from the first side 30 of the sensor 20 toward the opposite side 31. The second electrode 24 includes a plurality of second fingers 36 that extend on the surface 28 from the second side 31 of the sensor 20 toward the opposite side 30. The electrode 22 and the finger 34 are connected to the circuit (see FIG. 33) with a first polarity. The second electrode 24 and the finger 36 are interconnected with a second polarity to the detection circuit. Substrate 26 and fingers 34 and 36 are adapted to operate as lateral fringe capacitors or fringe effect capacitors and are thus formed. In some embodiments, a conductive shield (not shown) is placed on the lower surface of the substrate 26 (the surface opposite the surface 28). In the embodiment with a conductive shield, the sensor 20 has a fringe effect only from the surface 28 and only on one side. In the embodiment of sensor 20 where no shield is provided, the fringe effect acts on both flat sides of the substrate.

  FIG. 32 shows an example of a circuit 50 used in some embodiments of the present invention. Circuit 50 includes an oscillator 51 that provides input to sensor 20 and reference capacitor 53. The outputs of these two capacitors are supplied to the opposite locations of a quad diode ring 52. One intermediate point of the ring 52 is provided with a reference voltage. The other midpoint of the ring 52 is sent to an analog buffer that provides a DC output representing the ratio of the sensor 20 to the reference capacitor 53. In one embodiment, sensor 20 provides any capacitance from about 0 pF to about 200 pF. The circuit 50 is similar to a radio frequency phase discriminator and provides a direct current signal proportional to the phase difference of the signal supplied to the quad diode ring 52. Another reference to this general type of circuit is described in US Pat. No. 3,869,676. This patent is incorporated herein by reference. In some embodiments, circuit 50 is preferred because it uses fewer components and provides a direct output rather than a direct current offset.

  While some embodiments of the circuit 50 operate with an oscillator 51 that provides an input of either 10 kHz or 100 kHz, the basic behavior of the circuit 50 in some embodiments of the present invention is several hundred hertz to megahertz. It can be observed in the area. In some embodiments of the present invention, the oscillator 51 operates at a fixed frequency. In yet another embodiment, the oscillator 51 is a relaxation oscillator whose output frequency changes as the capacitance of the sensor 20 changes. One embodiment of the present invention uses a relaxation oscillator operating at about 120 kHz.

  The frequency is selected such that the conductivity and capacitance of the material (such as ice and liquid water) are within a predetermined range that is independent of frequency. Thereby, the effect | action which can isolate | separate the effect | action of ice and water and can determine a true electrostatic capacitance is acquired. In some of the illustrated embodiments, the distance between the electrodes is as small as about 0.1 mm, thereby providing sensitivity to droplets of this size. FIG. 17 is a graph showing the capacitance ratio as a function of ice thickness for the apparatus of FIG. FIG. 17 depicts a smooth curve 17-1 based on various measured values obtained in the laboratory.

  18A and 18B show the capacitance measurements obtained during the test. FIG. 18A includes curve 18A-1 showing capacitance as a function of time and curve 18A-2 showing temperature as a function of time. The central portion of curve 18A-1 and curve 18A-2 is relatively constant in nature, indicating the latent heat of water dissolution.

  FIG. 1 is a transcript from a substantially flat photograph of the top surface of a capacitive sensor according to one embodiment of the present invention. FIG. 1 itself is shown at a substantially constant scale ratio. The distance between the vertical portions of the electrodes 22 and 24 (ie, the distance between the “side rails” of the capacitive “ladder”) is about 2 inches.

  The sensor 20 includes a repeating pattern of four fingers interleaving on the substrate 26 repeated 3.5 times. Electrode 22 includes adjacent fingers 34.1 and 34.2 extending across substrate 26. The width of the finger 31 monotonously decreases from the side 30 toward the center line 32 of the sensor, and then monotonously increases as the electrode 24 is approached. The width of the finger 34.2 decreases monotonically from the side 30 toward the sensor centerline 32 and then decreases monotonically as the finger approaches the electrode 24. Adjacent fingers 34.1 and 34.2 are preferably separated by a constant gap 42.

  Electrode 24 includes fingers 36.1 and 36.2 extending from side 31 toward side 30 over surface 28 of substrate 26. Finger 36.1 extends adjacent to finger 34.1 and is separated from the edge of the opposing finger 34.1 by a variable gap 40.1. In one embodiment, the width of finger 36.1 varies across surface 28 in a mirror image with finger 34.1.

  The second finger 36.2 of the electrode 24 is arranged adjacent to the finger 34.2 of the electrode 22. The opposing edges of fingers 36.2 and fingers 34.2 preferably increase toward the centerline 32 of the sensor 20 and decrease as these fingers extend from the centerline to either side. They are separated by a variable gap 40.5.

  2, 3 and 4 are graphs showing some geometric relationships between the four fingers 34.1, 34.2, 36.1, and 36.2. FIG. 2 shows the relationship 72 between the width of the electrode fingers and the distance from the centerline (the distance zero is the centerline 32). Line A represents the width of electrodes 34.1 and 36.1 and increases as the distance from the center line increases. Line B represents the width of fingers 34.2 and 36.2 and decreases as the fingers move away from the centerline.

  FIG. 3 shows the relationship 74 between the gap between the fingers and the distance from the sensor centerline. Line C shows the gap between fingers 34.1 and 36.1 and increases as the fingers move away from the centerline. Line D shows the gap between fingers 34.2 and 36.2 and decreases as the fingers move away from the centerline.

  FIG. 4 shows the relationship 76 between the finger gap and the finger width for adjacent opposite polarity fingers. Preferably, finger pairs 34.1 and 36.1 share a similar relationship with finger pairs 34.2 and 36.2. In one embodiment, as indicated by line G, where the finger width is small, the gap between the opposite polarity fingers is preferably small. As the finger width increases, the gap between opposite edges of opposite polarity fingers likewise increases as well.

  The relationship indicated by lines A, B, C, D, and G is for adjacent fingers of opposite polarity. However, in some embodiments, the fingers are configured to form additional pairs of opposite polarity that are not adjacent. For example, finger 36.1 and finger 34.2 constitute another pair of opposite polarity electrodes separated by a variable gap. Line E in FIG. 3 shows this gap 40.3 between non-adjacent fingers. Line E has the same slope as line C, but with an offset representing a parallel gap 42. Similarly, line F shows a variable gap between non-adjacent fingers 36.2 and 34.1 of opposite polarity. This gap 40.4 is represented by line F, which has the same slope as line D, but is offset by a parallel gap 42.

  In the following description, the element number (NXX) is prefixed with an N series prefix and is the same as an element (XX) that does not include this prefix, except for the differences shown or described It is.

  10 and 11 show a variation of a fringe effect capacitor with variable gap and variable width. FIG. 10 shows a sensor 320 having a pair of electrodes 322 and 324 attached to the surface 328 of the substrate 326. The electrode 322 includes a helical finger 334. The finger 334 is adjacent to the finger 336 of the electrode 322, and the substrate 326 and the fingers 334 and 336 form a lateral fringe electrode and are so formed. The width of each finger 334 and 336 decreases as the fingers spiral toward the center of sensor 320. Further, the gap 340 between the opposing edges of fingers 334 and 336 decreases as the fingers spiral toward the center of sensor 320. The sensor 320 includes a larger gap 340.1 between the electrodes where the electrode width 338.1 is larger and a smaller gap between the electrodes where the electrode width 338.2 is smaller. 340.2 included. In this way, fingers 334 and 336 generally have a relationship 76 represented by line G in FIG.

  FIG. 11 shows a sensor 420 with a pair of opposite polarity electrodes 422 and 424 disposed on the surface 428 of the substrate 426. Each of the electrodes 422 and 424 includes fingers 434 and 436, respectively, extending along the length of the substrate 426. Fingers 434 and 436 of sensor 420 show the basic relationship 76 shown in line G, but are discrete or stepped, as shown by line H in FIG. As indicated by line H, the relatively large electrode width 438.1 is separated by a relatively large gap 440.1. As the electrode width 438.2 decreases, the gap 440.2 also decreases.

  Although the sensor 20 has been shown and described with a repeating pattern of interdigitated electrodes, the present invention is not limited thereto. Another embodiment of the invention contemplates a pair of electrodes having a variable width and a variable gap therebetween. As an example, such a sensor includes half of finger 36.1 and half of finger 34.1 adjacent. Another embodiment includes a half of finger 36.2 and a half of adjacent finger 34.2. Furthermore, the present invention contemplates embodiments in which there are no parallel gaps between adjacent electrodes.

  FIG. 19 illustrates a capacitive sensor 620 according to another embodiment of the present invention. The sensor 620 includes only four pairs of electrodes, and this shape can be considered as a subset of the electrode pattern shown in FIG. Furthermore, yet another pattern according to another embodiment of the present invention may include a pair of opposite polarity electrodes. These electrodes are not constant in width and are separated by a non-constant gap, for example, the width of one electrode increases in the same direction as the gap between the electrodes increases. Furthermore, it can be seen in FIG. 19 that various embodiments of the present invention do not have symmetry about the center line 632.

  5 and 6 show the test results of the sensor 520. FIG. The sensor 520 was placed closest to some amount of liquid water. FIG. 5 shows the total capacitance 66 of the sensor 520 as a function of the time that some amount of water was exposed to the freezing temperature. Line 68 shows the water temperature as a function of time. Note that the water maintains 0 ° C. over a period 70 corresponding to the latent heat of fusion of some amount of liquid water after linearly decreasing from about 20 ° C. to about 0 ° C. At the end of period 70, all water freezes and becomes a solid, and the temperature line 68 drops rapidly to the ambient temperature where the water has been exposed.

  FIG. 6 is a graph plotting the capacitance of sensor 520 as a function of water temperature. Note that the total capacitance 66 of sensor 520 varies from approximately 500 pF to a value less than 10 pF for solid ice. Sensor 520 provides a capacitance that varies evenly from when the water begins to freeze (ie, at the beginning of period 70) until when the last water is completely frozen (at the end of period 70).

  Sensors 20, 520, and 620 are sensitive to the formation of thin ice (which can be detected by a narrower width electrode spaced by a smaller gap) and change the capacitance accordingly, In response to thick ice at a greater distance from 28, the capacitance is changed (in response to the formation of ice closest to a wider electrode spaced by a larger gap). Because the width and gap of the electrodes of sensors 20 and 620 smoothly change from a large state to a small state, these sensors are also sensitive to the formation of ice of various thicknesses, and the capacitance can be reduced accordingly. Change. Because these sensors respond equally to ice formation, from the measured capacitance, the physical mixing of water (partially liquid and part solid) as a function of capacitance I can guess.

  FIG. 21 shows a top view, a side view, and a bottom view of a sensor assembly according to one embodiment of the present invention that has been packaged. In some embodiments, the sensor assembly is suitable for detecting a relatively thin ice layer. Sensor assembly 57 includes a housing 57.1 having a splined mechanical connector 57.2 for attachment to a surface, such as the surface of a refrigeration unit. Electrical connector 57.3 provides input and output excitation to circuit 50 located within housing 57.1. In one embodiment, sensor 620 is mounted on the surface of housing 57.1 so that it is closest to the position of the refrigeration unit where water freezes and becomes ice. The packaged sensor assembly 57 of FIG. 21 is illustrated at a constant scale, and in one embodiment, the package length is approximately 40 mm, as can be seen in FIGS. 21A, 21B, and 21C. In the same example, the width of the package is about 25 mm, as can be seen in FIGS. 21A, 21B, and 21C.

  Although a sensor whose capacitance changes in a state where there is water whose state changes from a liquid to a solid is shown and described, the present invention is not limited to this. The present invention contemplates inferring the physical state of any substance whose dielectric constant changes as it changes from one state to another. Furthermore, the present invention calculates measurements of material properties and features, such as the dielectric constant of the material, which varies with distance from the sensor.

  FIG. 16 is a top view of a flat capacitor known in the prior art. The capacitor 10 includes a first electrode 11 having a relatively large shape and a third electrode 13 having a relatively small shape. The intermediate electrode 12 has a shape compatible with both the first electrode 11 and the third electrode 13.

  FIG. 7 is a schematic view of an ice making machine according to an embodiment of the present invention. The ice making system 80 includes a movable assembly 82 with individual containers 84 positioned in a sub-freezing environment. Water is supplied to each container 84 from a water supply source 86. A motor 89 carries the assembly 82 toward the storage bin 90 by rotating one or more pulleys. The electronic control device 88 controls the operation of the water supply source 86 and the motor 89.

  The controller 88 receives signals from one or more sensors 20 or 620 that indicate the physical state of the water in the adjacent container. In one example, the sensor 20.1 changes capacitance as the dielectric constant of the water in the container 84.1 changes, thereby affecting the fringe field of the sensor 20.1. In some embodiments, the second sensor 20.2 is located closest to the second container 84.2. The controller 88 activates a motor 89 (in some embodiments, a container heating circuit or other feature (not shown)) based on the change in capacitance of the sensors 20.1 and 20.2, The partially frozen ice cube is dropped from the container 84.1 into the bottle 90. Preferably, the bottle 90 is also exposed to a sub-freezing environment and the released ice cube loses heat in the bottle 90 and freezes completely. By discharging the partially frozen ice cube, the freezing cycle is divided into the assembly 82 of the container 84 and the bottle 90. Since the freezing cycle is completed in the collection bin 90, the residence time of the ice cube in the container 84 is shortened. Thus, a large amount of ice can be formed within a given time. In another embodiment, a small amount of containers can form a given amount of ice. The sensor 20 can further be adapted to other aspects that increase the speed and / or increase efficiency of the ice machine.

  8 and 9 show another embodiment of the present invention. The ice maker 180 includes one or more ice sensors 120 built into the walls of a particular container 184. The first ice sensor 120.1 is located on the wall shared by the containers 184.1 and 184.3. The first sensor 120.2 is arranged on the wall shared by the containers 184.2 and 184.4.

  Each sensor 120 is the same as the sensor 20 except that the conductive shield is not provided on the rear surface 129 of the substrate 120. Thus, because the dielectric constant of substrate 126 is low, the fringe field of electrodes 122 and 124 extends from both top surface 128 and opposite back surface 129. Thus, the capacitance of sensor 120.1 varies in relation to the state of water in compartment 184.1 and the physical state of water in compartment 184.3.

  In an ice maker that forms ice cubes in an array of tray containers, one tray is adjacent to another tray, and the present invention is a sensor arranged to respond to ice formation in both containers. 120 is considered. In some embodiments, this doubles the capacitive output of the sensor. Furthermore, by configuring the sensor in this way, the physical state of two quantities of water is averaged in an analogy. In some such applications, the sensor can operate bidirectionally by eliminating the conductive shield of the substrate.

  In some embodiments of the present invention, a shared sensor is provided having electrodes that are parallel and of constant width. The gap and width are such that two adjacent ice cubes are so responsive to the thickness of ice that they are released into the storage bin with sufficient structural integrity. Yes. In another embodiment, the discharge procedure includes a sensor that responds to ice thickness in conjunction with a timed discharge operation after a predetermined thickness has been formed. Another embodiment of the invention contemplates a very thick electrode that can be used to fill the gaps between ice cubes. In another aspect, another embodiment of the present invention contemplates an electrode that is bent or formed from a thin stock that is proximate to each container but provides only a single electrical contact. Yes.

  FIG. 9 shows an assembly 282 of a container 284 according to another embodiment of the present invention. The assembly 282 includes a plurality of containers 284 that are arranged with the sides facing each other. The sensor 220 is the same as the sensor 120 except that each sensor is disposed on a wall shared with the side container.

  Some embodiments of the present invention include sensors in which fingers combined with each other are arranged according to a fractal pattern. The fractal pattern provides an electrode having a high capacitance per unit area of the substrate, and further varying the width and gap spacing. Furthermore, the electrode may be formed with a pseudo-fractal pattern. Furthermore, another embodiment of the present invention contemplates a space-filling fractal such as a Hilbert curve.

  The bee shown and described above is a method for producing ice using a capacitive sensor, but the present invention is not limited to this. Other embodiments of the invention include any type of sensor that emits signals that correspond to or can be inferred to: That is, the following refers to partially frozen ice that has sufficient physical integrity to discharge from the physical state of the ice cube, and / or the wall thickness of the ice cube, and / or from the container. The ability to discharge and continue and complete the freezing process at a location separate from the original container.

  Another embodiment of the present invention relates to an ice making method. This embodiment includes providing a source of liquid water, a container, and a sensor. This example further includes placing some amount of liquid water in the container and exposing the container to water or a temperature below the freezing temperature. The sensor detects a certain amount of freezing of the first portion and detects that a small amount of the second portion is liquid. Some amount of water is released after the detection. As a variant, this embodiment comprises freezing the second part after said release. In another aspect, an example includes placing a second amount of liquid water in a container after the release and before the freezing. In another aspect, this example includes exposing the released amount of water to a temperature below the freezing temperature of water after said release.

  Yet another embodiment of the present invention relates to an ice making device. This embodiment includes a water source. This embodiment further includes a first container and a second container sharing a wall, and subjecting the first and second containers to a predetermined temperature lower than the freezing temperature of water. This embodiment further includes an electronic sensor disposed proximate to the shared wall, the sensor comprising a first amount of partially frozen ice in the first container, and the second A signal corresponding to a second amount of partially frozen ice in the container is generated. In another aspect, in this embodiment, the capacitance of the sensor changes in relation to the physical state of the water.

  Another embodiment of the invention relates to a capacitor. This embodiment includes a substrate having first and second opposing sides and a surface therebetween. The embodiment further includes a first electrode attached to the surface closest to the first side, the first electrode having a first finger having a variable width extending toward the second side. Have. This embodiment further includes a second electrode attached to the surface closest to the second side, the second electrode having a second finger having a variable width extending toward the first side. Have. The second finger is spaced from the first finger by a variable width. In another aspect, this embodiment has a surface that is a first surface, and the substrate has a second surface opposite to the first surface, and the second surface further includes an electrical surface. A shield is provided. As another variation, this embodiment has a surface that is a first surface, and the substrate has a second surface opposite the first surface, the second surface having an electrical shield Is not provided.

  Another embodiment of the present invention relates to an ice making method. This embodiment includes providing a source of liquid water, a first container, a second container, and a sensor. This embodiment further includes placing a first amount of liquid water into the first container and placing a second amount of liquid water into the second container. The first container and the second container are exposed to a temperature below the freezing temperature of water. This embodiment further includes detecting with a sensor that the first portion of the first amount of water is frozen and the second portion of the first amount of water is liquid. A second amount of water is released after the detection. In another aspect, this embodiment includes performing the detection by sensing a first amount of capacitance.

  Another embodiment of the invention relates to an apparatus for sensing ice. This embodiment includes a substrate having first and second opposing sides and a surface therebetween. The embodiment further includes a first electrode attached to the surface and a second electrode attached to the surface, wherein the first and second electrodes are substantially parallel to each other, the first electrode The electrode and the second electrode are formed in a fractal pattern or a pseudo-fractal pattern, and the pattern is formed on ice having a thickness of about 2.54 mm to 7.62 mm (about 1/10 inch to 3/10 inch). It is designed to provide a variable capacitive response when it is closest. In another aspect, this example includes a Hilbert curve pattern.

  FIG. 12 illustrates an ice sensor 520 according to another embodiment of the present invention. The sensor 520 includes a first electrode 522 and a second electrode 524. Each of these electrodes is disposed on a surface 528 of the substrate 526. The first electrode 522 is electrically connected to the first capacitive element 534, and the second electrode 524 is electrically connected to the second capacitive element 536. These capacitive elements 534 and 536 have a curved shape, and element 536 is spaced from element 534 by a substantially uniform gap 540.3. Elements 534 and 436 are adapted to act as electrodes having fringe effect capacitance and are so formed.

  In the example of FIG. 12, capacitive elements 536 and 534 are generally hemispherical. Preferably, each capacitive element 534 and 536 has an equal width 538.4 and 538.3 respectively. Furthermore, these two capacitive elements are preferably separated by a gap 540.3 having a substantially uniform width. Referring to FIG. 12, this figure is a photograph and is therefore approximately isometric, with the outer radius of element 534 being about 1 inch. The electrode widths 540.3 and 538.3 are each approximately ¼ inch. The gap 540.3 is approximately 6.35 mm (1/4 inch).

  Although a sensor having capacitive elements of uniform width separated by gaps of uniform width is illustrated and described, the present invention is not limited thereto. The present invention further contemplates embodiments in which the curved capacitive element has a variable width as described above, and the width of the gap between the electrodes is variable as described above. ing.

  13A and 13B show another embodiment of the present invention. In this embodiment, the sensor 520 is configured to be mounted in an ice making container 584.1. Preferably, the capacitive elements 534 and 536 follow the overall shape of the ice container 584.1 and the gap 540.3 is arranged away from the edge of the container 584.1 and towards the inner volume of the container. Are arranged. By arranging the gap in this way, it has been found that the sensor provides a measurable change in capacitance when the phase of water in the container 584.1 changes.

  14A and 14B show an ice container 584.2 incorporating a modified sensor 520.2. Sensor 520.2 is the same as sensor 520 except that the overall capacitive element has a semicircular shape that is smaller than a hemispherical arc. The present invention further contemplates embodiments in which the shape of the ice container is not a hemisphere as shown in FIGS. 13A and 14A. For example, the present invention further contemplates embodiments in which the container is arbitrarily shaped and a fringe effect capacitive element sensor is attached to one surface of the container. Preferably, in these variants, at least part of the gap between adjacent capacitive elements corresponds to the inner part of the vessel where the water phase change is slow, or more preferably the water phase change is slowest Place in the position of the container to be used.

  Another embodiment of the invention relates to an ice making device. The apparatus includes a plurality of containers, each of which includes a plurality of sides that define an internal volume. Each container has an opening for introducing water and discharging ice. A fringe effect capacitor is provided on one side of the container. In another embodiment, the capacitor includes at least two capacitive elements and a gap between these elements. The capacitor is so formed that the gap is arranged on one side closest to the center of the volume.

  15 and FIGS. 17-21 relate to various features of various embodiments of the present invention. As an example, FIG. 19 shows one pattern for an electrode for a fringe effect frost sensor.

  FIG. 15 schematically illustrates the effect of one layer of material interacting with the electric field of the fringe effect capacitor. FIG. 15A shows the sensor 20 placed on the substrate 26. Electrodes 22 and 24 support an electric flux field 21a1. The substrate 26 has a first relatively small electric flux field 21 b 1 outside the substrate 26. FIG. 15B shows the effect of a thin layer of material 19 (such as water) closest to electrodes 22 and 24. The outer electric flux field 21b2 expands due to the presence of the substance 19, thereby increasing the capacitance of the sensor 20. FIG. 15 shows sensor 20 with a thick layer of material 19 on electrodes 22 and 24 and substrate 26. Although the outer flux field 21b3 is large, it indicates a further change in the capacitance of the sensor 20. In all three views of FIG. 15, the bundles 21a1, 21a2, and 21a3 are substantially unaffected by the material 19, at least as a first order approximation.

  Referring to FIG. 15 again, the electric flux fields 21b2 and 21b3 are increased by contact with the substance. It will be appreciated that in embodiments where the material 19 is ice, the dielectric constant is about 3 and the sensor 20 responds to some change in its dielectric constant from 1 to 3. It is understood that in embodiments where the sensor is placed in contact with liquid water after being exposed to air, the sensor responds more strongly to change at least a portion of its dielectric constant from 1 to 80. Let's do it.

  Accordingly, capacitive sensors according to some embodiments of the present invention can measure the presence and / or thickness of frost on the surface, or the presence of solid ice for making ice cubes. Some embodiments can distinguish between solid ice, ice trapped in air or water, or soft ice. Some embodiments can be pre-configured with respect to sensor configuration and circuit characteristics for measuring various frost or ice thicknesses. Furthermore, the methods and apparatus described herein allow ice cubes to be manufactured based on the actual state of a particular ice cube, rather than simply based on a predetermined model of the ice cube.

  FIG. 20 is a schematic view of adjacent electrode pairs provided on the substrate. The first electrode pair includes electrodes 34.01 and 36.01 having opposite polarities. The adjacent second electrode pair provided on the substrate includes electrodes 34.02 and 36.02 having polarities corresponding to the first pair. Similarly, some embodiments of the present invention include adjacent third and fourth electrode pairs, which also have alternating polarities.

  Multiple electrodes with opposite polarity (electrodes 36.01, 36.02, 36.03, and 36.04 in FIG. 20) share the response of a single electrode (electrode 34.01 in FIG. 20) It was determined by analysis that it can be influenced by the electric flux field. A curved line 20-1 shows a bundle line between adjacent conductors. The presence of a relatively small amount of water near the electrodes 34.01 and 36.01 has a “local” effect on the capacitance of the system. A small amount of water (water limited by surface tension, a small amount of ice or snow particles, etc.) does not affect other electrodes because the water is only present locally. However, when a relatively large amount of water extends from the electrode 34.01 to the second pair of electrodes 36.02 (caused by the generation of a relatively large amount of water droplets and a relatively large amount of frost), the bundled wire is .01 and non-adjacent electrodes 36.02. Curves 20-3 and 20-4 indicate that as the amount of water or ice on the surface of the electrode gradually increases, the bundle line from the first electrode 34.01 of the first polarity is the electrode of the second opposite polarity. Indicates that it will be shared with 36.01, 36.02, 36.03, and 36.04. It will be appreciated that the greater the separation distance to non-adjacent electrodes, the smaller the contribution of the bundle to the overall signal.

  22 to 31 relate to yet another embodiment of the present invention for making ice. In the following description, the prefix of the number 1Y column is used at the beginning of the element number (1YXX), which is the element with 1000 prefixes unless a change is shown or described. The same thing as (10XX) is pointed out.

  Some embodiments of the present invention relate to the use of capacitive sensors to detect water state changes from a liquid state to a solid state. The present invention is not limited to water, and can be applied to any substance having different capacitive characteristics between a liquid state and a solid state.

  One embodiment of the present invention relates to the use of a portion of an ice making device as an integral part of a capacitive sensor. As discussed below, an ice maker with an evaporator tube near the ice can use the tube as one electrode of a two-electrode capacitor. However, the present invention is not limited to using the refrigerant evaporator tube as one capacitive electrode. The present invention further contemplates embodiments in which other parts of the ice making device are used as one electrode of a capacitive sensor. Preferably, the portion of the ice maker selected as the capacitive electrode must be of good electrical conductivity and be located closest to at least one location where ice is formed.

  In some embodiments of the present invention, the second electrode of the capacitive ice sensor is a conductor arranged in a pattern corresponding to the position and shape of the ice formed in the ice making container. As an example, the second electrode may comprise a wire, foil, tube, or other cross-sectional shape, suspended in an ice making container, embedded in a container wall or other structure, and bonded to the container, Coated on the surface of the container, or otherwise placed at a location corresponding to ice formation. However, other embodiments of the present invention are not limited to using the second electrode as described herein. The present invention further contemplates embodiments in which the second electrode is a second portion of an ice making assembly, such as a vessel wall or other structure, a water inlet, or other component. Preferably, the second electrode is not in electrical communication with the first electrode except for a capacitive field of water to be frozen.

  In some embodiments of the invention, the ice is formed closest to the evaporator of the refrigeration unit. The evaporator is suspended in a liquid water bath. The thickness of the ice wall continues to increase as cold refrigerant is pumped through the evaporator. In an embodiment where the evaporator has a plurality of fingers depending downwardly, ice forms around the individual fingers, and the wall thickness of these individual ice shapes is determined by the evaporator below the freezing point. Continues to increase over time.

  By monitoring the thickness of the formed ice wall with a capacitive sensor, the ice-making process can be performed when the measured ice wall thickness (estimated from the change in capacitance) is within a predetermined range. It can be finished. At that time, the temperature below the freezing point of the evaporator tube is terminated by the operation of the electronic controller of the refrigeration unit, and the ice shape can be removed from the finger by warming the evaporator tube.

  This operation according to the method of the present invention is quite different from the current method of operation in which the wall thickness of the ice form is inferred from the time the evaporator was at a temperature below freezing. This time-based method of operation can cause adjacent finger ices to join together into one or more excessive ice shapes. This type of improper operation occurs when the timed ice maker is interrupted in the first cycle and over time is taken at a sub-freezing finger in the subsequent second cycle.

  In yet another embodiment of the invention, water is placed in a plurality of individual containers that correspond in size and shape to the final ice cube. Place the entire container in a volume below the freezing point. In such an embodiment, a capacitive ice sensor is used to infer the wall thickness, which also corresponds to the volume of unfrozen water contained within the wall of the partially frozen ice cube.

  Although the embodiment shown and described above relates to a capacitive sensor for detecting the formation of ice in an ice making machine, the present invention is not limited to this. Another embodiment of the invention relates to an apparatus and method for detecting ice formation on roads, aircraft wing leading edges, engine inlets, and other locations where it is desirable to detect ice formation.

  An embodiment of the present invention is shown in FIG. The ice making system 1020 uses a finger evaporator of the refrigeration system as one of the two electrodes of the capacitive ice sensor. The finger evaporator is an integral part of the ice making machine 1020 that forms an ice cube.

  One way to form an ice cube is to use a multi-finger (generally 12 fingers) evaporator. In this evaporator, closed end finger 1032 is suspended in a water bath of container 1024. Referring to FIGS. 22-28, the finger 1032 extends from a common evaporator tube assembly 1030 that is U-shaped. FIG. 32 is a drawing created from a photograph of a portion of the ice making machine 120 according to one embodiment of the present invention. It can be seen that the closed end finger 1032 depends downwardly from the evaporator tube 1030. Container 1024 is shown in a partially rotated downward direction away from finger 1032. Cold refrigerant is introduced through the condenser tube inlet 1030a. The warmed refrigerant exits through the outlet 1030b of the tube 1030. As is common in ice making assemblies, the refrigerant is warmed as it removes heat from the water surrounding the individual fingers 1032 during the freezing process. Although a U-shaped evaporator tube with fingers has been illustrated and described, the present invention is not so limited, and it is contemplated to use any shape of evaporator tube including linear, circular, and helical. Yes.

  As the ice making operation proceeds, the refrigerant in the evaporator tube fingers cools and freezes the water surrounding each finger, forming an increasing thick wall. The overall shape of the resulting ice cube 1026 can be described as having a thimble shape. 23A and 23B are a side view and a plan view, respectively, of an ice cube 1026 formed by the ice making system 1020. Ice cube 1026 includes pockets 1027 formed around corresponding fingers 1032. Although shown and described here is a thimble-shaped ice cube formed around the fingers of the evaporator tube, the present invention is not limited to this, for example, ice of any shape such as a cube or a sheet. Formation is conceivable.

  24 is a schematic plan view of a part of the ice making machine of FIG. A 2 × 2 array of fingers 1032 is shown. An ice cube 1026 corresponding to the finger is formed. In one embodiment, the tube wall formed is between about 8.35 mm and 10.16 mm (about 0.35 inch to 0.4 inch), and between the walls of adjacent ice cubes is 2.54 mm to 5.08 mm ( A gap of 0.1 inches to 0.2 inches remains. The diameter of the evaporator fingers is about 0.4 to 0.5 inches (about 10.16 mm to 12.7 mm). These dimensions are merely examples and are not intended to limit any embodiment of the present invention.

  Referring again to FIG. 22, the ice making system 1020 includes a capacitive sensor formed from a first electrode 1034 and a second electrode 1040. The first electrode 1034 is electrically connected to a condenser tube assembly 1030 having a plurality of fingers 1032. As discussed above, this first electrode is not limited to the condenser tube of the ice making system, but may be another conductive part of the ice making system proximate to the formed ice cube.

  The second electrode 1040 is arranged in an area of the ice making system 1020 in which ice is formed in the ice making container 1024 (or embedded in the container 1024). The second electrode 1040 of the system 1020 includes two conductor strips 1040a1 and 1040a2. The evaporator tube 1030 and its plurality of fingers 1032 are U-shaped between this second pair of electrodes of the capacitive sensor. Many different forms of the second electrode 1040 are possible. The second electrode is physically separated from the first electrode and electrically insulated from the first electrode. An example of one form for the second electrode 1040 is the loop shown in FIG. 25, where the second electrode surrounds all fingers of the first electrode according to the wall of the water bath. Another example of location is molding into the inner wall 1124a of the container 1124, the outer wall 1124b of the container 1124, or the wall of the container 1124. Good sensor performance was obtained when it was provided on the inner wall (see FIG. 25). This is because there are no plastic walls or plastic wall portions of the other two forms of containers mentioned above.

  FIG. 22 illustrates an ice making system 1020 according to one embodiment of the present invention. The ice making system 1020 includes a capacitive ice sensor, the first electrode of which is the evaporator tube 1030 and its fingers 1032. A lead wire 1034 is electrically connected to the evaporator tube 1030 and is further electrically connected to the capacitive measurement circuit. The second electrode of the capacitive ice sensor includes two conductor strips 1040a1 and 1040a2. These spatially spaced conductors are electrically connected to act as a single electrode for the capacitive ice sensor.

  FIG. 25 illustrates an ice making system 1120 according to one embodiment of the present invention. The ice making system 1120 includes a capacitive ice sensor, the first electrode of which is the evaporator tube 1130 and its fingers 1132. A lead wire 1134 is electrically connected to the evaporator tube 1130 and is further electrically connected to the capacitive measurement circuit. The second electrode of the capacitive ice sensor includes a conductive electrode 1140 b that loops around the evaporator finger 1132. A lead wire (not shown) electrically connects the electrode 1140b to the capacitive measurement circuit.

  FIG. 26 illustrates an ice making system 1220 according to one embodiment of the present invention. The ice making system 1220 includes a capacitive ice sensor, the first electrode of which is the evaporator tube 1230 and its fingers 1232. A lead wire 1234 is electrically connected to the evaporator tube 1230 and is further electrically connected to the capacitive measurement circuit. The second electrode of the capacitive ice sensor includes a conductor 1240c formed in a scalloped pattern. These scallops generally correspond to the final shape of the produced ice cube. A lead wire (not shown) electrically connects the conductor 1240c to the capacitive measurement circuit. Although a scalloped shape has been illustrated and described, other embodiments of the present invention include various shapes of ice cubes, such as rectangular ice cubes, and corresponding electrode shapes overall.

  FIG. 27 illustrates an ice making system 1320 according to one embodiment of the present invention. The ice making system 1320 includes a capacitive ice sensor, the first electrode of which is the evaporator tube 1330 and its fingers 1332. A lead wire 1334 is electrically connected to the evaporator tube 1330 and is further electrically connected to the capacitive measurement circuit. The second electrode of the capacitive ice sensor includes a conductor assembly 1340d0 disposed centrally within the U-shaped evaporator tube 1330 and the container 1324. The conductor assembly 1340d0 includes seven pins 1340d2 depending downward (ie, in the plane of the paper as viewed in FIG. 27), which extend along at least a portion of the height of the evaporator finger 1332. Pins 1340d2 are interconnected by wire 1340d1. The conductor assembly 1340d0 is electrically connected to the capacitive measurement circuit. In one embodiment, pins 1340d2 are provided along either side of the finger so that a 2 × 6 array of fingers has seven pins as shown in FIG. However, the present invention contemplates that only one and a few pins are located closest to the area where the ice cube is to be formed.

  FIG. 28 illustrates an ice making system 1420 according to one embodiment of the present invention. The ice making system 1420 includes a capacitive ice sensor, the first electrode of which is the evaporator tube 1430 and its fingers 1432. A lead wire 1434 is electrically connected to the evaporator tube 1430 and further electrically connected to the capacitive measurement circuit. The second electrode of the capacitive ice sensor includes a conductor assembly 1440e0 disposed centrally within the U-shaped evaporator tube 1430 and the container 1424. In one example, conductor assembly 1440e0 includes a conductor loop configured to form five rhombus-shaped structures 1440e2 interconnected by conductors 1440e1. In another embodiment, each of the diamond-shaped structures 1440e2 'is interconnected by a single conductor 1440e1' from one point of the diamond to the closest point of the adjacent diamond. Preferably, the diamond-shaped structure 1440e2 is centrally located between four adjacent fingers of the 2x2 portion of the total evaporator assembly.

  A second electrode having a shape corresponding to a U-shaped evaporator tube having a plurality of fingers depending downwardly is shown and described. As discussed above, the present invention contemplates any shape of evaporator tube. Preferably, the second electrode has a shape of an evaporator tube, a shape of an ice cube that has been taken out, a shape of a container of an ice making machine, a shape of a container for individual ice cubes, or a combination of these shapes and the whole It has a shape corresponding to.

  In some embodiments of the invention, the first electrode is part of an existing structure in the ice machine. This is an expensive method. In the embodiment shown in FIGS. 22 to 28, an electrical connection is made between the evaporator and the measuring circuit. Referring to any of these drawings, this connection is made by connecting directly to the evaporator or by connecting to an equivalent point in the refrigeration system, for example, a liquid line that feeds the evaporator. be able to.

  The dielectric constant between the two electrodes changes to change the capacitance. This change in capacitance can be measured by a measurement circuit. In this case, a liquid water bath provides the starting dielectric. As heat is removed from liquid water during a change of state to solid state ice, the dielectric constant of the same volume of water changes from the dielectric constant associated with water to the dielectric constant associated with ice. The dielectric constant of water is about 80, and the dielectric constant associated with ice is about 3. Accordingly, the change in dielectric constant is 27: 1. However, the present invention contemplates embodiments in which the change in permittivity is not limited to 27: 1 materials, and the change in permittivity of materials undergoing state changes is as low as 5: 1.

  In some embodiments of the present invention, the first and second electrodes of the capacitive ice sensor are provided on a controller, preferably a digital controller. In another embodiment, the controller receives a signal corresponding to the temperature in the ice machine container. Preferably, the controller measures the capacitance between the first and second electrodes, and in some embodiments, corrects the measured value based on the temperature signal.

  This state change from a homogeneous bath to a bath in which ice cubes are formed can be modeled as a piecewise integral. This situation can be modeled approximately because many capacitors are connected in series, and each one change in these series capacitor elements is taken into account by analysis. The number of capacitors used in the analysis is related to the smoothness of the resulting function. Twenty elements can be used for reasonable results.

  The initial state for performing an analysis of one embodiment of the present invention is a homogeneous water bath, with all pieces being considered having a high dielectric constant of 80. This is modeled by a series capacitor set to an arbitrary initial capacitance value. Calculate and record the total capacitance value of the series capacitor network. As ice begins to form on each finger 1031, the ice is initially very thin and then gradually thickens. Progress is analyzed separated by separate elements. The first step after the initial state is a step in which the first integrated element changes completely from water to ice and the corresponding dielectric constant for this element changes from 80 to 3. In the model, the first element changes to an initial value divided by a dielectric constant ratio, ie, a value of capacitance divided by about 80/3. Calculate and record the total capacitance value of the series capacitor network. The next capacitor is modified by the same factor to model the complete change of the next water bath segment from water to ice. Calculate and record the total capacitance value of the series capacitor network. This is continued until all baths change state from water to ice. It should be noted that this model is longer than if an ice cube was actually manufactured using a finger evaporator according to some embodiments of the present invention. This is because, in some embodiments, the ice cubes are removed before the entire water bath becomes solid ice. By discharging early in this way, the total production amount of the ice making machine can be increased. This is because when a partially frozen ice cube that has been removed continues to change state to a fully frozen state in another container in the freezing area, the ice cube is used to create the next generation ice cube. This is because the manufacture of can be started.

  FIG. 29 is a graph showing the normalized capacitance of a capacitive ice sensor according to one embodiment of the present invention as a function of the water state closest to the sensor as the water changes from a liquid state to a solid state. . Using this relationship 1099 between normalized capacitance and% of ice frozen state, in some cases, when the estimated wall thickness before changing to a completely solid state is a predetermined value, You can start taking out a 1st generation ice cube. For example, an electronic controller receives a signal from a capacitive ice sensor. A first measured value of capacitance is obtained when liquid water is introduced into the container 1024. When the freezing cycle is started, the control device periodically measures the capacitance of the ice sensor. This instantaneous capacitance is normalized with the initial capacitance to determine how much the capacitance has changed during the freeze cycle. For example, a 90% decrease in capacitance indicates an ice cube that is about 35% frozen. A 95% decrease in capacitance is indicative of ice cubes that are about 70% to 80% frozen.

  FIG. 30 shows three clusters of measured data regarding the radial wall thickness of ice cube 1026 (see FIGS. 23A and 23B) as a function of the weight of the cube. For example, if it is desirable to have a radial wall thickness of about 0.35 inch to 0.38 inch, the corresponding weight of the cube is about 10.5 g to 11.5 g. It is in the range.

  FIG. 31 relates to ice sensor capacitance versus time for various forms of second electrodes. Curve 1196 relates to the capacitance with respect to time for the loop electrode 1140b shown in FIG. Curve 1296 shows the capacitance versus time for the scalloped second electrode 1240b shown in FIG. Three curves 1396 with respect to capacitance as a function of time are shown for an electrode array containing five pins similar to that shown in FIG. FIG. 27 shows a second electrode 1340 that includes seven pins 1340d2 that extend generally parallel to finger 1332 and interconnected by conductors 1340d1.

  FIG. 34 illustrates an evaporator assembly 1050 according to another embodiment of the present invention. The evaporator assembly 1050 is configured as a heat exchanger and includes one or more tubes 1052 having a plurality of U-shaped bends 1053. A plurality of fins 1051 are in heat transfer contact with one or more tubes 1052. Refrigerant or coolant is pumped through tube 1052. This coolant removes heat from the tube and cools the fins by heat transfer contact with the fins. Air passes through the evaporator 1050 and is thereby cooled and then used in refrigeration or cooling. In some applications, the fins are about 10 mm or 5 mm apart. A typical thickness of the fin is about 0.3 mm.

  In many cases, the air cooled by the evaporator 1050 contains moisture, and this moisture adheres to the fins 1051 and the tubes 1052 as frost. A sensor of the type described hereinabove may be added to the evaporator 1050 to provide a signal indicating frost formation. In some embodiments of the present invention, the frost sensor 20 'is positioned at the bend 1053 of the tube. In other embodiments, a sensor, such as sensor 57 ', is positioned closest to a portion of tube 1052 between adjacent fins 1051. The use of the prime indication (') for 57' and 20 'is that of sensor 57 or 20 described above, except that it is adapted to be attached to the evaporator assembly and so formed. Showing each one.

  In yet another embodiment of the present invention, sensors 20, 520, 620, or other inventive sensors described herein are used to remove frost that has accumulated in the evaporator. As discussed above, when ambient air is blown onto the evaporator, frost is formed in the evaporator, and in embodiments where the sensor 20 is closest to the evaporator, frost is also formed in the capacitor. As a result, frost accumulates closest to the capacitor electrode, and the bundle changes. This is because the dielectric constant of frost is different from air and as a result changes the capacitive response of the sensor. The measured change in capacitance can be provided to the operator (in the case of an embodiment where the “frost light” is turned on by a change in capacitance) or can be used by an electronic controller to activate the evaporator defrost cycle Let

  The evaporator and capacitive sensor are heated by flowing heated fluid through the evaporator, as is commonly done during defrosting operations. When the frost first changes to liquid water, the capacitance of the sensor increases. This is because the dielectric constant of liquid water is higher than that of frozen water. Then, by continuing to apply heat, liquid water is evaporated, resulting in a decrease in the capacitance of the sensor. These changes in capacitance (increasing towards the liquid phase and decreasing after evaporation) are used to inform the operator that the defrost cycle is complete. Similarly, an electronic controller that senses capacitance increases and decreases turns off the heat source to the evaporator.

  In general, a measurement circuit according to one embodiment of the present invention provides a capacitive input and output that can be easily integrated into an ice machine control system or frost control system. Common outputs are analog voltage, pulse width modulation output, or digital output format that varies with ice formation on the evaporator fingers.

  One embodiment of the present invention includes a container for holding liquid water, a refrigeration unit for removing heat from the water in the container, and a capacitance of the water by sensing the capacitance of the water in the container. The ice making apparatus includes means for providing a signal corresponding to the refrigeration unit and a control device operably connected to the refrigeration unit, wherein the control device operates the refrigeration unit in response to the signal.

  In some embodiments, the sensing means is a fringe effect capacitor. In another embodiment, the fringe effect capacitor has at least two electrodes, and the water in the container is a dielectric for the two electrodes. In yet another embodiment, the sensing means is a capacitor having two electrodes, and the water in the container is a dielectric for the two electrodes. In another embodiment, one electrode of the capacitor is part of the refrigeration unit. In yet another embodiment, the control device is a digital control device having a memory that contains data relating to the capacitance of water and the predetermined thickness of ice in the container. Yes.

  An embodiment of the present invention includes a refrigeration unit for removing heat from water, the refrigeration unit being disposed closest to a position where liquid water changes to ice, and liquid water. A conductive second member disposed closest to the position where the state of the ice changes to ice, wherein the first member is electrically insulated from the second member and spaced from the second member. And a circuit electrically connected to the first member and the second member, the circuit corresponding to a capacitance of water between the first member and the second member The present invention relates to a device for sensing the capacitance of water, which generates a signal to perform.

  In some embodiments, the first member is an evaporator tube. In another embodiment, the first member has a first feature immersed in water, and the second member has a second feature corresponding to the first feature. Yet another embodiment includes a container for holding water, wherein the refrigeration unit can remove heat from the container, the container has a predetermined shape, and the second member includes the container It has a shape corresponding to the shape.

  Another embodiment of the present invention provides a container for holding liquid water, obtaining a first measurement of the capacitance of the water, removing heat from the water, and some of the liquid water Changing the state to ice, obtaining the second measured value of the water capacitance after depriving of heat, and comparing the first measured value with the second measured value. It relates to an ice making method.

  In one embodiment of the invention, the comparing is dividing the second measured value by the first measured value. In another embodiment, the comparing includes subtracting one of the second measurement value or the first measurement value from the other of the second measurement value or the first measurement value. Yet another embodiment includes determining whether a certain amount of ice has been formed by the comparison. Another embodiment includes stopping removing the heat after the determination. In yet another embodiment, the providing includes a capacitor for obtaining the first measurement value and obtaining the second measurement value, wherein at least some of the state changing water is a dielectric of the capacitor. Is the body. In another embodiment, the first member has a first feature immersed in water and the second member has a second feature corresponding to the first feature. Yet another embodiment includes a container for holding water, wherein the refrigeration unit is capable of removing heat from the container, the container has a predetermined shape, and the second member is disposed on the container. It has a shape corresponding to the shape.

  While the invention has been illustrated in the accompanying drawings and described in detail in the foregoing description, it is to be considered as illustrative and not as restrictive but merely as illustrated and described in preferred embodiments. It will be understood. It is desirable to protect all variations and modifications that fall within the spirit of the invention.

FIG. 1 is a top view of a capacitive sensor according to an embodiment of the present invention. FIG. 2 is a graph showing electrode width versus distance from the sensor centerline for the apparatus of FIG. FIG. 3 is a graph showing electrode gap versus distance from the sensor centerline for the apparatus of FIG. FIG. 4 is a graph showing the electrode gap with respect to the electrode width from the sensor centerline for the apparatus of FIG. FIG. 5 is a graph showing capacitance and temperature for the apparatus of FIG. 1 as a function of time. FIG. 6 is a graph showing the capacitance as a function of temperature for the apparatus of FIG. FIG. 7 is a schematic view of an ice making machine according to an embodiment of the present invention. FIG. 8 is a schematic view of an ice making machine according to another embodiment of the present invention. FIG. 9 is a schematic view of an ice making machine according to another embodiment of the present invention. FIG. 10 is a top view of a sensor according to another embodiment of the present invention. FIG. 11 is a top view of a sensor according to another embodiment of the present invention. FIG. 12 is a top view of a sensor according to another embodiment of the present invention. FIG. 13A is a side view of an ice container according to one embodiment of the present invention. FIG. 13B is an end view of the apparatus of FIG. 13A. FIG. 14A is a side view of an ice container according to another embodiment of the present invention. FIG. 14B is an end view of the apparatus of FIG. 14A. FIG. 15A is a schematic diagram showing the fringe flux between a pair of surface conductors on a dry surface. FIG. 15B is a schematic diagram showing the fringe flux between a pair of surface conductors in contact with a thin ice layer. FIG. 15C is a schematic diagram showing the fringe flux between a pair of surface conductors in contact with a thick ice layer. FIG. 16 is a plan view showing a prior art form in which three conductors are arranged on an insulating surface. FIG. 17 is a graph showing the relationship of capacitance ratio to ice thickness for the apparatus of FIG. FIG. 18A is a graph illustrating the capacitance of some ice in contact with a fringe effect capacitor according to one embodiment of the present invention. FIG. 18B is a graph of the process of FIG. 18A showing some amount of water capacitance as a function of its temperature. FIG. 19 is a top view of a fringe effect capacitor according to another embodiment of the present invention. FIG. 20 is a schematic diagram of paired electrodes showing the effect of non-adjacent electrodes for sensing the phase transition of a substance in contact with the electrodes. FIG. 21A is a top view of a packaged frost sensor according to one embodiment of the present invention. FIG. 21B is a side view of the sensor of FIG. 21A. FIG. 21C is a bottom view of the sensor of FIG. 21A. FIG. 22 shows an ice making machine according to another embodiment of the present invention taken from above. FIG. 23A is a side view of an ice cube. FIG. 23B is a top view of the ice cube of FIG. 23A. 24 is a schematic diagram of a portion of the apparatus of FIG. FIG. 25 shows an ice making machine according to another embodiment of the present invention from above. FIG. 26 shows an ice making machine according to another embodiment of the invention shown from above. FIG. 27 shows an ice making machine according to another embodiment of the present invention taken from above. FIG. 28 shows an ice making machine according to another embodiment of the present invention from above. FIG. 29 is a graph showing the normalized capacitance of water as a function of the liquid or solid state of water. FIG. 30 is a graph showing ice cube radial wall thickness versus cube weight. FIG. 31 is a graph showing the capacitance of various ice sensors as a function of time. FIG. 32 is a perspective view of a part of an ice making machine according to an embodiment of the present invention. FIG. 33 is a schematic diagram of a circuit according to one embodiment of the present invention. FIG. 34 is a perspective view partially drawn from a photograph of an example of an evaporator according to an embodiment of the present invention.

Claims (43)

In ice making equipment,
A container for holding liquid water;
A refrigeration unit for removing heat from the water in the container;
Means for sensing the capacitance of water in the container and providing a signal corresponding to the capacitance of the water;
A control device operably connected to the refrigeration unit and operating the refrigeration unit in response to the signal. The apparatus of claim 1.
The apparatus, wherein the sensing means is a fringe effect capacitor. The apparatus of claim 2.
The apparatus, wherein the fringe effect capacitor has at least two electrodes, and the water in the container is a dielectric for the two electrodes. The apparatus of claim 1.
The sensing device is a capacitor having at least two electrodes, and the water in the container is a dielectric between the two electrodes. The apparatus according to claim 4.
The refrigeration unit includes an evaporator having at least one tube, and one of the electrodes is the tube. The apparatus according to claim 4.
The control device is a digital control device having a memory, wherein the memory contains data relating the capacitance of the water to a predetermined thickness of ice in the container. In a device for sensing the capacitance of water,
A refrigeration unit for removing heat from the water, comprising a conductive first member located closest to the location where liquid water is transferred to ice;
A conductive second member disposed closest to a position where liquid water changes to ice, wherein the first member is electrically insulated from the second member and from the second member A conductive second member spaced apart; and
And a circuit in electrical communication with the first member and the second member for generating a signal corresponding to a capacitance of water closest to the first member and the second member. The apparatus of claim 7.
The apparatus, wherein the first member is an evaporator tube. The apparatus of claim 7.
The first member has a first feature immersed in water and the second member has a second feature corresponding to the first feature immersed in water. The apparatus of claim 7, further comprising:
A container for holding water, wherein the refrigeration unit can remove heat from the container, the container has a predetermined shape, and the second member has a shape corresponding to the shape of the container. The device. The apparatus of claim 7.
The conductive first member has a plurality of first fingers,
The conductive second member has a plurality of second fingers,
The apparatus, wherein the first finger is combined with the second finger. In the ice making method,
Providing a container for holding liquid water;
Obtaining a first measurement of the capacitance of the water;
Removing heat from the water and turning some of the liquid water into ice;
Obtaining a second measurement of the capacitance of the water after the deprivation;
Comparing the first measurement value with the second measurement value. The method of claim 13, wherein
The comparing is a method of dividing the second measured value by the first measured value. The method of claim 12, wherein
The comparing includes subtracting one of the second measurement value or the first measurement value from the other of the second measurement value or the first measurement value. The method of claim 12, further comprising:
Determining whether a certain amount of ice has been produced by said comparison;
Stopping said removal after said determining. The method of claim 12, wherein
The providing includes a capacitor for obtaining the first measurement value and obtaining the second measurement value, wherein at least some of the changing water is a dielectric of the capacitor; Method. The method of claim 12, further comprising:
Determining by the comparison that the water closest to the center of the container is liquid water enclosed in a partially formed ice cube;
Draining the partially formed cube from the container. In a method for detecting a phase change of a substance,
Providing a container containing a quantity of material in a first physical state;
Obtaining a first measurement of the capacitance of the substance;
Changing the heat content of the material and transferring at least a portion of the material to a second phase different from the first phase;
Obtaining a second measurement of the capacitance of the substance including the portion after the change;
Comparing the first measurement value with the second measurement value. The method of claim 18, wherein
The comparing is a method of dividing the second measured value by the first measured value. The method of claim 18, wherein
The comparing includes subtracting one of the second measurement value or the first measurement value from the other of the second measurement value or the first measurement value. The method of claim 18, further comprising:
Determining whether said certain amount of the predetermined portion has transferred by said comparing;
Stopping said changing after said determining. The method of claim 18, wherein
The providing includes a capacitor for obtaining the first measurement value and obtaining the second measurement value, wherein at least some of the transferred material is a dielectric for the capacitor. There is a way. 23. The method of claim 22, wherein
The capacitor is a fringe effect capacitor, wherein the transferred material is adapted to change the fringe electric field of the capacitor and so formed. The method of claim 18, wherein
Changing the heat content is by removing heat from the material. The method of claim 18, wherein
Changing the heat content is by applying heat to the material. The method of claim 18, further comprising:
Stopping changing the heat content based on the comparing. 27. The method of claim 26.
The providing includes a heat exchanger for changing the heat content of the material in the container;
Evacuating the portion from the container based on the comparing. 27. The method of claim 26.
One of the first physical state and the second physical state is a solid state, the other is either a gas state or a liquid state, and the liquid is enclosed in the substance of the solid phase Discharging the phase or the some amount of the gas phase. In the heat exchange device,
An evaporator having at least one tube and a plurality of fins attached to the outside of the tube, the fins arranged and configured to exchange heat with a fluid flowing in the tube;
Thermally connected to one of the tube or the fin, having a flat first electrode, the first electrode being separated from the flat second electrode by a gap, the first electrode being long A capacitor having a thickness and a width, wherein one of the gap or the width varies along the length;
The device wherein the first electrode and the second electrode are adapted to change the capacitance between these electrodes in response to the formation of frost between these electrodes and are so formed. 30. The apparatus of claim 29.
The apparatus, wherein the width increases in the first direction along the length. The apparatus of claim 30, wherein
The apparatus, wherein the gap between the first electrode and the second electrode increases in the same direction along the length. In an evaporator for a refrigeration system that transfers heat from a fluid,
Having an outer wall defining a lumen, said lumen being for the flow of refrigerant therethrough, adapted to facilitate the flow of heat to said refrigerant and a tube so formed; ,
A capacitive sensor in thermal communication with the tube, comprising a first electrode, wherein the first electrode is separated from the second electrode by a gap, and the first length of the first electrode is A capacitive sensor in electrical communication with a second length of two electrodes, wherein the gap between the first length and the second length is not constant along the first length;
An evaporator, wherein a substance from the fluid condenses in the vicinity of the gap by the heat flow, and the condensed substance changes an electric flux between the first length and the second length. The apparatus of claim 32.
The apparatus, wherein the gap monotonously increases in a direction along the first length. 34. The apparatus of claim 33.
The device, wherein the first electrode has a variable width, the width monotonically increasing in the direction. The apparatus of claim 32.
The apparatus, wherein the first electrode has a first variable width, the first width monotonically increasing in a direction along the first length. 36. The apparatus of claim 35.
The apparatus, wherein the second electrode has a second variable width, the second width monotonically increasing in the direction. The apparatus of claim 32.
The apparatus wherein the fluid is air and the condensed material is frost. The apparatus of claim 32.
The first electrode is in a first polarity, the second electrode is in a second polarity, and a third of the second polarity is inserted in the gap between the first electrode and the second electrode. A device comprising an electrode. The device of claim 32, further comprising:
An electrical circuit including a reference capacitor having an input electrode and an output electrode;
An oscillation voltage source;
Having at least four diodes arranged in a four-arm bridge,
One of the first electrode or the second electrode and the input of the reference capacitor receive an input from the voltage source;
The apparatus, wherein the other of the first electrode or the second electrode and the output of the reference capacitor are separately provided on an arm on the opposite side of the bridge. In a method for defrosting a heat exchanger,
Providing a heat exchanger and a capacitor, wherein frost is at least partially formed on the outside in both the heat exchanger and the capacitor;
Obtaining a first measured value of the capacitance of the frosted capacitor;
Heating the heat exchanger and the capacitor;
After the heating period, obtaining a second measurement of the capacitance of the capacitor;
Comparing the first measurement value to the second measurement value;
Stopping said heating in response to said comparing. 41. The method of claim 40, wherein
The method, wherein the capacitor is a fringe effect capacitor. 41. The method of claim 40, wherein
The method, wherein the heat exchanger is an evaporator of a refrigeration system. 41. The method of claim 40, wherein
The comparing includes distinguishing between melted frost and evaporated frost.

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