JP3269551B2 - A device for controlling the dimensions of an ice bank - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method and an apparatus for detecting a state of change from liquid to solid and from solid to liquid. In particular, the invention relates to determining when a solid state of a material has formed at a location contained within the material by monitoring the electrical resistance of the liquid.
The present invention relates to an apparatus or method used to control the size of an ice bank in a cooling device using water or other liquid as a coil and a heat sink. The invention also relates to a device used to house and separably couple an electronic circuit, particularly an electronic ice bank control circuit used to hold liquid at refrigeration temperatures.

BACKGROUND OF THE INVENTION A typical cooling device for cooling cold beverages or other fluids is through a line (or coil) immersed in water or other liquid maintained at a freezing temperature. Drinks are circulating. A compressor or other cooling means is used, which circulates the coolant through the cooling coil immersed in water or other liquid to form an ice arrangement around the cooling coil. Thus, the liquid state of water or another liquid is maintained at the freezing temperature in equilibrium with its solid state. The frozen liquid around the coil is called an ice bank. Heat is transferred from the drink to the water or other liquid, causing the ice surrounding the cooling coil to thaw. Therefore, the ice bank operates as a heat sink for cooling the drink. However, as long as enough ice is present, the water is kept at the freezing temperature. The heat transferred from the drink is absorbed as the latent heat of thawing and the temperature of the water does not change. However, the circulation of the compressor and coolant causes new ice to form in the thawed ice portion if the device is operating continuously. Therefore, it is necessary to provide a closed-loop control device that detects the amount of ice around the cooling coil and appropriately operates the compressor. A device for controlling the size of the ice bank in such a cooling device, that is, an ice bank control device, is realized by ice detecting means separated from the cooling means by a predetermined distance, and the operation of the cooling means is performed according to the distance. Control. While the cooling device is cooling the liquid, the liquid is usually circulated radially outward from the cooling coil, so that the ice bank is predetermined at the time the cooling cycle of the cooling means is interrupted by the ice bank controller. The ice bank control device performs a control operation so as to grow to the specified size.

Conventional ice bank controllers were generally of the mechanical type. These devices commonly use capillaries containing a solvent that freezes when the capillaries are surrounded by ice. The expansion of the frozen solvent in the capillary then presses on the partition that operates the electronic switch. An electronic switch turns the cooling compressor on or off, thereby controlling the size of the ice arrangement.

However, recent ice bank controllers use electronic sensing means to determine the presence of ice. In such a device, the electrodes are immersed in water and current flows from one electrode to the other electrode held at ground potential. If a constant current source is used, the potential of the first electrode will be proportional to the resistance of the water or other medium. Therefore, the presence of ice can be detected because the electrical resistance of the liquid changes (generally, the resistance value increases) when the liquid transfers to the solid form and changes. When such sensing means are combined with appropriate control means, a closed loop feedback controller is constructed, in which the cooling means (typically consisting of a compressor) keeps the water at the freezing point but forms excess ice. Control so that it does not work.

Such an ice bank controller can provide a number of effects over mechanically similar devices, and is less expensive and more accurate. Since the electrical resistance of solid state water is much higher than that of liquid state water, such monitoring has enabled a fairly accurate determination of the presence of ice. Also, since electronic devices measure state changes directly rather than indirectly by measuring temperature, changes in the freezing point of water caused by the addition of solids can cause these devices to fail. Is not affected. Since the cooling means of the device for performing such ice bank control is activated or deactivated, the control device is usually "on-off" or "bang-bang".
g) "Referred to as a controller. With such a device, the resistance of the water around the cooling coil is compared to a reference value, and if there is a difference, an error signal is generated to close the compressor. In the prior art, the reference value is typically a solidified standard value that is considered according to the resistance of the liquid water.

The resistance of the water used to generate the error signal (hereinafter "variable resistance") is monitored at a predetermined location at a predetermined distance from the cooling coil. If the value of the variable resistor at that location rises above a reference value, the conventional method indicates that ice has formed at the predetermined location, and this indication indicates an interruption of the cooling process.

A fundamental feature of all on-off controllers is the variably controlled vibration with respect to the set point. Because the actuators of such devices are operated in an on-off fashion, when the operation is off, ambient guidance occurs such that controlled fluctuations are away from the set point. This generates an error signal, turns off the actuator until the error signal decreases to zero, and the cycle repeats. While such a cycle is common, it is not preferred if the cycle is too fast, especially if the actuator is a mechanical device such as a compressor. A rapid start-stop cycle ("rapid cycle") results in over-use of the compressor and inefficient use of energy.
A well-known technique for solving this problem is to add a "dead band" to the controller. "Deadband" is a range of controlled variations that are allowed to leave the set point before the actuator is activated or turned off. Thus, if the controlled variation is between the high and low set points,
There is no change in the previously generated error signal and the actuator remains on or off. Thus, the range between the high and low set points is effectively a "dead band". In water cooling applications, precise control related to controlled fluctuations is not necessary, since the purpose of the controller is simply to prevent the formation of excess ice around the cooling coil. Therefore, adding a "dead band" to the device is not without significant disadvantages.

Most conventional similar methods for water cooling control simply involve measuring the electrical resistance between a single probe and a ground reference. Circuits and other means are connected to the probe to measure this resistance and compare it to a predetermined fixed resistance, the predetermined fixed resistance being predetermined as a standard for water. . The fundamental problem with such an approach using reading a single resistor is that there is no means to provide a dead band. The absence of a dead band creates the practical problem described above, and the compressor undergoes a rapid start-stop cycle (rapid cycle) as ice development approaches the probe immediately. In order to overcome this rapid cycle problem, dead bands must be incorporated into the controller either by mechanical or electronic means.

Another conventional method involves monitoring resistance sensing from two probes. The use of two probes in this latter method provides an effective provision for dead bands. Deadband is achieved by the electronic requirement that both probes detect ice to stop the compressor, while the ice melts away from both probes to operate the compressor again. Predetermined values for water resistance have been routinely used as reference values for this and other conventional methods, respectively. This conventional method involves positioning a first of the two probes near a cooling coil to detect ice development prior to a second probe and to melt the ice after the second probe. Detecting is included. Thus, a dead band occurs when the first probe detects ice and when the ice melts around the second probe. When the device is this device, the compressor is maintained on either its previous mode of operation, on or off. If the total amount of ice pack surrounding the cooling coil is seen as a controlled variation, the device will detect that variation between the two set points respectively represented by ice surrounding the first and second probes. Make it vibrate.

Unfortunately, since each of the prior art inventions is responsive to a fixed, predetermined value in the resistance of the liquid water, the display of the results obtained is not always accurate, This is because extraneous and non-standard factors affect the reading of resistance in the water tank, especially after extended use. Basically, the resistance of water varies with different geographic locations based on partial impurities in the water, which generally increase the resistance of the water. The resistance of liquid water also changes in the apparatus over time due to evaporation of water, which elevates the amount of impurities retained per volume of water.

Increased resistance of liquid water also results from increased amounts of impurities in the system as they accumulate over time. Employment of similar methods also creates problems in systems where the content of impurities or the identity of the liquid is intentionally altered. Under these circumstances, the reference value must be changed,
This introduces a delay, especially when the circuit has to be changed. In addition, deposits on the immersed electrical probe often affect resistance measurements, which naturally occur over time. The additional resistance of the deposited impurities adds to the resistance read by the probe, thereby increasing the apparent resistance of the water. Over time, such a coating of impurities will inevitably adhere to any probe that is immersed in the least impure liquid water. In particular, these coatings tend to be of uniform thickness on surfaces that are susceptible to similar environments. Electroplating on a probe can also affect the apparent resistance of water recorded by such a probe. Electrolytic-type deposits were minimized in the manner described above by utilizing AC rather than DC. However, in practice, slight electrolytic plating still occurs with alternating current. Thus, the electrical probes required for any use of the technology must be periodically replaced or cleaned when incorporated into a prior invention for use.

Thus, the present invention provides a method of indicating the phase transition of liquid from water to ice, while measuring the variation in water resistance as well as the apparent variation caused by impurities deposited on the electrical probe. It is an object to provide an apparatus and a method.

The present invention also aims at measuring the apparent resistance of a liquid. This measured apparent resistance is used as a reference rather than a fixed or predetermined value. Thus, changes in the composition of the water are automatically compensated. It is also an object to compensate for changes in the probe itself. Deposits, electroplating or other factors may also be compensated.

It is a further object of the present invention to provide means for attaching the aforementioned probe to an ice bank control system for use. The mounting of the probe (or "electrode") must ensure that the ground and reference electrodes must always be immersed in liquid water. Two ice sensing electrodes or probes must be mounted so that the ice bank defines a space where growth is allowed by the control system.

Still another object of the present invention is to be able to adjust the size of the ice bank according to a change in the operating state. For example, if there is a large period of use, it is desirable to increase the heat capacity of the heat sink. By increasing the size of the ice bank, the cooling system can have greater control over the entire beverage without reducing the temperature of the aquarium. Also, different dimensions and configurations of the vessel, including the aquarium and associated cooling coils, may dictate different optimal dimensions of the ice bank. Therefore, it is desirable that the electrode mounting means allow the user to adjust the size of the ice bank to suit individual applications.

A related object is to provide detection means in the form of a plurality of probes, having means for mounting on the coils of a cooling system forming an ice bank. In the cooling system, the attaching means has a feature that is advantageously correlated with and provides the adjustment of the position of the probe.

The present invention also provides an electrode and mounting means for use in an ice bank control system of the type described above which renders the electrode relatively resistant to mechanical damage when the cooling coil is lowered into or removed from the water bath. The purpose is to: During such operation, there is always the possibility that the electrodes will contact the sides of the aquarium container or the beverage coil.
It is therefore desirable to minimize the possibility of electrode breakage or deformation, as the location of the electrode is critical to the operation of the ice bank control system. For example, if the reference electrode is broken or bent during the installation of the cooling coil, so as to prove that the probe position is critical, it is placed closer to the cooling coil than the ice detection electrode. The control system will never shut off the compressor and the entire aquarium will freeze as a result. This allows the entire cooling system to be completely destroyed.

Still another object of the invention is to provide a means by which the electrodes can be easily replaced in the first effort. As mentioned above, the plating is unavoidable in any such control system. If the resulting deposits on the electrodes are severe enough to warrant replacement of the electrode, any time spent during the replacement operation by the serviceman is uneconomical. Also, the time that the entire system must be shut down adds expense to the cooling system user. It is therefore desirable that the electrodes can be removed and replaced with minimal time and effort by the electrode mounting means.

In addition, previous methods have utilized a grounded electrode reference that depends on the system using it. It is insulated. It presents special problems when the method is used in containers or systems. Therefore, another object of the present invention is to
Incorporating the use of a ground probe that is independent of the system using the above method.

It is another object of the present invention to effectively minimize electroplating and coating of an electric probe used therein.

It is another object of the present invention to provide an apparatus that makes use of the method and makes it usable.

Still another object of the present invention is to provide an apparatus for detecting whether or not a substance at a specific position is distinguished from a substance at another position, particularly by determining a difference in electric resistance between the two positions. And Still another object of the present invention is to provide means for detecting the presence or absence of a solid phase in a liquid phase. Note that the means include protective features that ensure their desired operation.

Another object of the present invention is to provide a method for detecting the presence of any substance in the solid phase within the liquid phase of any substance, including but not limited to water.

It is also an object of the present invention to avoid the rapid circulatory movement of the device associated with the particular adoption of the invention by providing a dead zone.

In addition, with the advent of electronic ice bank controllers, special packaging and connection equipment requirements have arisen. Accordingly, it is another object of the present invention to provide a housing for an electronic control circuit that serves to protect electronic components and electrically conducting surfaces from contact with water.

It is a further object of the present invention to provide means for easily removing and replacing a printed circuit board on which elements of an electronic control circuit are mounted. Since all electronic components will eventually fail, their removal and replacement should be done with minimal time and effort to reduce service costs. A lot of time and effort can be saved by minimizing the number of electronic and mechanical connections that must be disconnected before an electronic circuit can be removed. Accordingly, it is an object of the present invention to provide a connection means for a printed circuit board that includes an electronic circuit capable of removing the printed circuit board without affecting the power supply connection or the connection of the sensor.

Still another object of the present invention is to provide a unit integrated with the housing, which can observe the state of the final control output of the electronic circuit. It is desirable that the final control output always has the contacts closed, so that the state of the contacts can be observed without removing the housing and using a voltmeter at the output terminal. For example, when the entire cooling device is operating,
It is necessary to determine whether the electronic control circuit is operating properly independently of the compressor operation.

SUMMARY OF THE INVENTION Many features disclosed and / or encompassed by the present invention are disclosed in US Patent Application No. 051,08, filed May 15,1988.
No. 0, U.S. Patent Application No. 124,157 filed November 23, 1987,
Alternatively, it is disclosed in a U.S. patent application filed on November 14, 1988.

The present invention includes and provides an apparatus for monitoring the electrical resistance of a material and comparing its resistance to a reference value to determine the presence of a solid phase in a liquid. The present invention also includes and provides for continuously monitoring the apparent resistance of the liquid and using this monitored value as a reference rather than using a predetermined fixed value. Since the variable resistance measured by the control probe and the reference resistance measured by the reference probe are in the same liquid, the effects of resistance distribution at different geographic locations and over time are thus eliminated. . The effect of probe deposition and coating is practically uniform on each probe, and the increased apparent resistance monitored by the control probe with the deposit increases the apparent resistance monitored by the reference probe with a similar deposit. This continuously monitored criterion also eliminates the effects of probe sticking and coating, as compensated by the apparent resistance provided.

Ice banks controlled in relation to ice formation (ice banks)
As employed in feedback systems such as (ice bank) controllers, the present invention provides for mitigating rapid circulation by including the provision of dead bands. Two control probes are arranged so that the second control probe is close to the first control probe but at a greater effective distance from the cooling coil.
When ice is sensed by both the first and second probes (indicated by an increase in resistance to ground), the device turns off the cooling means. Conversely, when the first and second probes sense water (indicated by the same ground resistance as the reference probe), the cooling means is turned on. Moreover, the present invention provides for the use of a grounding probe that is independent of the container or other part of the system containing the liquid in which the monitoring method is employed. The present invention also utilizes alternating current rather than direct current to minimize the electroplating effect caused by direct current.

Other devices that enable and utilize the methods of the present invention are also provided. Such a device has four electrical probes that measure a reference resistance and two variable resistances and provide a common ground. A circuit for performing display and control of the present invention is also included.

The apparatus of the present invention also comprises mounting means for mounting an electrical probe (or "electrode") to a portion of the cooling coil. The device also includes a structure for attaching the electrode and a cable connected to the electrode. The electrodes are metal springs having a current carrying surface. This metal spring is mounted on a single electrode mounting block. In a preferred embodiment, a total of four electrodes are used, two of which are used as ice sensing electrodes, one as a reference electrode, and one as a ground electrode. The probe attachment means is designed such that the ice ridge is attached to a part of the cooling coil that grows around it. Therefore, the reference and ground electrodes must be located at a greater distance from the cooling coil than either of the two ice sensing electrodes. Since the two ice sensing electrodes define the radius of the cooling coil in which the control device allows the growth of the ice ridge, the reference electrode and the ground electrode are always immersed in water. In a preferred embodiment,
Proper spacing of the electrodes is achieved by the shape of the electrode mounting block so that the same length of spring is used for all four electrodes. The orientation of the electrode mounting block is set such that when the probe mounting means is mounted on a portion of the cooling coil, the spring is oriented in a direction perpendicular to the length of the cooling coil. The shape of the electrode mounting means is step-shaped such that the two springs used as reference and ground electrodes are at a greater distance from the cooling coil than the other two springs. Also, since the mounting block is stepped, the springs used as the ice sensing electrodes are located at different distances from the cooling coil to provide the aforementioned dead band function.

The electrode mounting block is mounted on the cable housing so that the cable is connected to the spring in the watertight compartment. The ends of the spring and cable are connected with a standard quick disconnect. An electrode mounting block (also called a "probe cartridge") fits into the cable housing to provide a waterproof seal. Because the interior of the cable housing is filled with epoxy or an equivalent material, the cable can exit the other side of the cable housing without compromising the integrity of the watertight section where the spring and cable are connected. it can.

The cable housing is slidably mounted in a slot formed by the truss member of the probe mounting means. The probe attachment means provides a means by which the means can be attached to a portion of the cooling coil. By slidably mounting the cable housing in the slot of the probe mounting means, the distance of the four electrodes from the cooling coil is adjustable. An adjustment member is provided that removably engages the probe cartridge to secure the probe cartridge in place.

The apparatus of the present invention also includes two housings for housing the circuits and other features of the present invention and for operatively connecting them with other elements. The first housing contains, in particular, an electronic printed circuit board, and the second housing contains terminals and connections for power and sensor cables. The circuit board housing is designed to fit on the upper surface of the terminal housing and is fixed with one screw. In this position, the flat pins provided on the printed circuit board are inserted into specially designed slots in the terminal housing to provide electrical connection between the printed circuit board and the cable terminals.
The device provides a unique means of connecting the flat pins to the terminals, providing a stable mechanical connection and a low resistance electrical connection.

Cable enters the terminal housing through the slot. Each cable is bent into an S shape by the ridge of the terminal housing, and then attached to the screw terminal. Bending the cable by the ridges helps to prevent the cable from being inadvertently pulled loose from the terminal connection.

When the circuit board housing is mounted on top of the terminal housing, the terminal housing is partially mated with the circuit board housing. In a preferred embodiment of the present invention, it is used to house the electronic control circuitry of an ice ridge cooling system, a feature that prevents water from reaching the flat pins or cable terminals of a printed wiring circuit if water accidentally splatters. To do.

At the top of the circuit board housing is provided a circular small lens that receives and converges light from the light emitting elements of the printed wiring board. In a preferred embodiment of the invention, a lamp is mounted on the printed circuit board and electrically connected in series with the contacts controlling the operation of the compressor. This feature allows the user of the present invention to monitor the condition of the contacts, and thus the operation of the control circuit, by observing the condition of the lamp through a lens mounted on the top of the circuit board housing. That is, the operation of the control circuit can be monitored independently of the operation of the compressor without separating the printed wiring circuit board.

These and other objects, features and advantages of the present invention will become apparent in light of the following detailed description when considered in conjunction with the accompanying drawings of the preferred embodiment. The foregoing and following description of the invention is provided for illustrative purposes only, and the true spirit and scope of the invention is set forth in the following claims.

EXAMPLE The apparatus of the present invention for performing and using the method of the present invention is shown in conjunction with a compressor 101, which performs a cooling operation of an ice bank 99 with a cooling coil 100 when powered. Compressor 101 is powered by DC power supply 20 by means further discussed in this application. The compressor 101 and the cooling coil 100 are components of a cooling device including a bath of liquid water 98. When the compressor 101 is powered, the ice bank 99 grows in size and
The periphery of the ice bank 99 advances outward from the coil 100. When the compressor 101 is not powered, the ice bank 99 melts and the periphery of the ice bank 99 is drawn inward toward the coil 100.

The device of the present invention is configured to be equidistant (FIG. 1 and FIG.
4 as shown in the embodiment of FIG. 4). The configurations and dimensions of the probes 5 to 8 are similar to each other. Probes 5, 7, and 8 are each connected to line 14-
It is in electrical communication with the control circuit of the present invention via 16. The probe mounting device 10 is made of an electrically insulating material, and connects the positions of the probes 5 to 8 to each other and the ice bank 99.
Are rigidly connected to the probes 5 to 8 for fixing in relation to. The preferred embodiment of the probe 5-8 and probe mounting apparatus 10 is discussed in more detail in connection with FIGS. 2-4. It is in electrical communication with each probe 5, 7, 8 or an AC power supply 12 which is a device for generating an AC. The operative connection with the AC power supply 12 is for applying an AC current to the probes 5, 7, and 8. Probe 6 is a ground probe,
It is connected to an appropriate ground G by electrical communication. Probe 6 is a common ground for probes 5,7,8. Lines 14, 15, 16 are insulated conductors that operatively connect the AC power supply 12 to the respective probes 5, 7, 8 and thereby provide an AC current to each of the probes 5, 7, 8. The alternating current of each line 14-16 is
With the alternating current of each of the other lines. Measured at any point along the insulated conductors 14, 15, 16;
The peak to peak of the equivalent amplitude and phase of the voltage produced by the alternating current is due to the resistance between probe 6 and probes 5, 7, 8 due to the current amplitude being kept constant through each insulated conductor. Each is proportional.

Converters 24, 25, and 26 are connected to leads 21, 22,
It is operatively connected in electrical communication with the conductors 14, 15, 16 insulated by 23. Converters 24, 25, 26 convert the alternating current to a direct current signal, the amplitude of which is proportional to the peak-to-peak amplitude of the alternating signal. The rectified AC signal is then filtered before entering comparators 34,35.
Converters 24, 25, 26 are also operatively connected in electrical communication with DC current 20 to enable the operation of the AC current to the DC current. DC power supply 20 is further operatively connected to AC power supply 12 to receive AC power from AC power supply 12. DC power supply 20 includes a device that exchanges the received alternating current to direct power to all circuits of the device that require DC power. DC
The power supply 20 is, like the logic and control unit 36, the converter 24,
Common power supply for 25 and 26. Converters 24, 25, 26 are the same in their electrical characteristics.

Leads 27, 28 and 29 are connected to converters 24, 25 and 26 respectively
Converters 24 and 2 respectively to derive a DC signal from
It is operatively connected to 5, 26 in electrical communication. Comparator 34 receives the DC signal from leads 27 and 28 and
It is operatively connected to compare the signals from 7, 28. Comparator 35 is operatively connected to receive the DC signals from leads 27 and 29 and compare the signals with the signals from leads 27 and 29. Comparators 34 and 35 have similar electrical characteristics. The electrical characteristics of each comparator 34 and 35 are such that when the compared input signals are different, a high signal is produced and when the compared input signals are the same, a low signal is produced. Thus, the high output signal from the comparator indicates the presence of ice around the control probe 7 or 8 that inputs to it.

The logic and control unit 36 is operatively connected in electrical communication with the comparators 34 and 35 via leads 37 and 38, respectively. Comparator 34 provides an electrical comparison signal to logic and control unit 36 via lead 37. Comparator 35 communicates the appropriate electrical comparison signal to logic and control unit 36 via lead 38.

Logic and control unit 36 includes appropriate electrical circuitry to analyze the comparison signal received via leads 37 and 38. Logic and control unit 36 further includes an electrical circuit for transmitting electrical signals to control the operation of compressor 101. The control signal is transmitted via output wire 39. The circuit of the logic and control unit 36 is powered by the DC power
Logical and control unit 3 to engage and disengage 101
The operation of the compressor 101 is controlled by a device incorporated in 6. Output wire 39 is operatively connected to the circuitry of logic and control unit 36 and is operably connectable to compressor 101 to enable electrical communication between logic and control unit 36 and compressor 101.

The circuitry of the logic and control unit 36 is such that the compressor 101 is turned off when both comparators 34 and 35 produce a high signal corresponding to the ice around both probes 8 and 7. The compressor is started when both compressors 34 and 35 produce a low signal corresponding to the water around both probes 7 and 8. The output of any other combination from the comparator does not change the operating state of the compressor.

In operation, probes 5 to 8 are placed in water in water or a water-based solution,
Is the probe closest to the source of ice production and the preferred direction in which ice production proceeds. Such a location is
1 is shown in FIG. 1 as forming outwardly from coil 100. Although FIG. 1 illustrates the invention used in a device containing water, the invention can also be used in any device containing a liquid that transitions to a solid phase, where the solid phase can be distinguished from the electrical resistance of the liquid phase Has electrical resistance.

Thus, when alternating current is provided from the alternating current power supply 12 via the insulated conductors 14, 15, 16, current also flows from each probe 5, 7, 8 to the ground probe 6. The resistance between the ground probe 6 and the probe 5 is a reference resistance. The resistance between the probe 7 and the probe 6 and the resistance between the probe 8 and the probe 6 are variable resistances. Until the progress of the storage of the ice bank 99 stops when the ice bank 99 surrounds the probe 7, the material surrounding the probes 5 and 6 is always liquid, as will be further evident in this discussion.

The method of the present invention is also schematically illustrated in FIG.
The method of the present invention can utilize an apparatus similar to the apparatus of the present invention. For this reason, the components of the device of the invention are referenced in the description of the preferred method of the invention. The method includes a first selected location submerged in liquid water, the location being selected to approximate the desired volume limit of the ice bank 99. After the predetermined position has been selected, the probes 7 and 8 are placed in a predetermined position with the probe 8 located closer to the cooling coil 100 than the probe 7. Probes 6 and 5
Is then located at a greater distance from the cooling coil 100. The insulated conductor 17 is electrically connected to an object to be electrically grounded. As soon as the probe 5-8 is located, the AC power supply 12 and the DC power supply 20 are operated to power the electrical circuits of the device of the present invention. The power supply operation of the electric circuit enables the operation of the device of the invention.

As a result, the periphery of the ice bank 99 is increased, so that the probe 8 is
8 will be the first. As the perimeter of the ice bank 99 further increases, the probe 7 is surrounded by ice, and the resistance between the probe 7 and the ground probe 6 exceeds the reference resistance. Therefore, each of the comparators 34 and 35 outputs the high signal to the logic and control unit 36.
To be transmitted. Upon detecting that both comparators have gone high,
The logic and control unit 36 transmits an electric signal to interrupt the cooling operation of the compressor 101. The cooling operation of the device is thus stopped, and the ice bank 99 stops growing significantly. As soon as the operation of the compressor is interrupted, the ice bank 99 begins to melt there. When the ice bank 99 is unwound from around the probe 8, the logic and control unit 36 detects that the resistance between the probe 8 and the ground probe 6 equals the reference resistance, and the logic and control unit 36 detects An electrical signal is transmitted to the compressor 101 to restart the operation of 101. The ice bank 99 subsequently ceases to melt, and the storage of the ice bank 99 increases again towards the probe 7.
Operation of the device is vaguely continued to effectively control the size of the ice bank 99 in this manner. As a result, the operation of the apparatus of the present invention coupled to the compressor 101 and the cooling coil 100 implements and utilizes the method of the present invention in a preferred manner.

The method according to the invention basically comprises the following steps. That is, the method according to the invention comprises the step of selecting a location in the liquid water, which location is about the limit of the expansion of the perimeter of the ice bank 99, which is desirable for the practitioner of the invention. Is done. Further, the method of the present invention comprises operating the circuit of the device of the present invention with current from an AC power supply 12 and a DC power supply 20;
Representing the reference resistance as an electrical signal by the circuit and transmitting it through conductor 21; and similarly expressing the variable resistance as an electrical signal and transmitting it through conductors 22 and 23 to converters 25 and 26, respectively. Filtering the electrical signals transmitted through lines 21, 22 and 23 to minimize undesired electrical properties in the signals; and converting the electrical signals from lines 21, 22 and 23 into converters 24, 25 and 26, respectively. Converting to a DC signal by the converters 24, 25 and
These DC signals from 26 are connected to conductors 27, 28 and
Communicating to comparators 34 and 35 through 29, which causes the DC signal on lead 28 and the lead
Comparing and determining the potential difference between the DC signal of 27 and the comparator 35 comparing and determining the potential difference between the DC signal transmitted through the conductor 29 and the DC signal transmitted through the conductor 27 by the comparator 35. The steps and the respective potential differences determined by the comparators 34 and 35 are represented as electrical signals, and these signals are
Communicating to the logic and control unit 36 through and 38, and from the electrical signals transmitted through conductors 37 and 38 to determine the desired operation of the compressor 101 to melt and cool the ice bank 99. Utilizing the unit 36 and controlling the operation of the compressor 101 in accordance with the logic and the determined value of the control unit 36.

More specifically, the method for determining and controlling the operation of compressor 101 by logic and control unit 36 includes several steps. For purposes of illustration, these steps will begin with the first start of compressor 101. However, the method of the present invention can be used at any stage of the ice bank 99 manufacturing process. The determination and control of the compressor 101 by the logic and control unit 36 includes the following steps, i.e., applying power from the DC power supply 20 to the compressor 101 to start operation of the compressor 101 and form the ice bank 99. Starting from when the resistance between the probes 7 and 6 is greater than the reference resistance, and when the power supply from the DC power supply 20 to the compressor 101 The step of determining when the compressor 101 stops running and the melting of the ice bank 99 is interrupted, and from the electrical signal transmitted through the lead 38, when the resistance of the material between the probes 8 and 6 becomes equal to the reference resistance Equal or when the compressor 101 is re-powered from the power supply 20 and the ice bank 99 grows again It includes determining whether started, a step of continuing these steps above. In this manner, melting and regrowing the ice bank 99 is continued for a period of time, as desired by the practitioner of the present invention.

FIG. 2 is an exploded view of the probe mounting means 10 'and the probe cartridge 250. The probe cartridge 250 has springs 5'-8 ', a combination of which is collectively referred to as a "loadable probe" of the present invention.
The mountable probes (which are also shown in FIGS. 3 and 4) have features that function as probe mounting means 10 and probes 5-8 as shown in FIG. I have. However, the relative positions of the mountable probes are fixed by the physical characteristics of the probe cartridge 250 according to a predetermined desirable relationship. The springs 5'-8 'of the mountable probe function as probes 5-8, respectively, along with means for positioning and adjusting the spring relative to the cooling coil 100 of FIG. In order to associate the mountable probe shown in FIGS. 2 to 4 with the probe system of FIG. 1 and the electrical circuit of FIG.
Numbers are assigned to correspond to.

The probe mounting means 10 'functioning as a part of the probe mounting means 10 of FIG.
40, a mounting bolt 242 and a nut 243. As is clear from FIG.
The shaft is received through the slot 241 of the adjusting member 240, the hole 245 of the truss member 229, and the hole 246 of the truss member 230 in a straight line, and then screwed into the nut 243. . In this manner, the mounting bolt 242 is provided at an operating position for mounting the springs 5 'to 8' to the cooling coil 100 and the ice bank 99 formed around the coil. Truss members 229 and 230 are each lower members
There are various cross members, including 228 and a central member 268, which reinforce the structure of the respective truss members and engage cooling coils therebetween. Each truss member 229 and 230 has holes 245 and 246, respectively.
At the center thereof have cylindrical projections 211 and 212. The cylindrical protrusions 211 and 212 are for reinforcing the connection of the mounting bolt 242 through the holes 245 and 246, respectively. The cylindrical protrusion 211 has two stepped keys 221 (only one of which is shown), and these keys protrude radially at opposing positions. As is apparent from FIG.
Reference numeral 1 extends parallel to the mounting bolt 242 in the longitudinal direction. The cylindrical projection 212 has an upper central recess 249 indicated by a broken line in FIG. The upper central recess 249 has a size and shape corresponding to the size and shape of the nut 243, so that the central recess accommodates the nut 243 therein and the nut 243 is connected to the center axis of the mounting bolt 242. To prevent it from rotating around.

Once the mounting bolt 242 is in its operative position, the mounting bolt 242 is screwed into the nut 243 and tightened to pull the truss members 229 and 230 toward each other, thereby connecting the probe mounting means 10 'to the truss members 229 and 230.
It is fastened to the cooling coil 100 located between. When the truss members 229 and 230 are tightened together in this way,
Grooved receiving members 247 and 248, each having an inwardly directed groove aligned with the central axis of the mounting bolt 242, align with the respective key 221 and slidably receive the keys. In this manner, the grooved receiving members 247 and 248 function to align and slidably receive the cylindrical projection 220 of the truss member 229, and thus,
Ensure that 9 and 230 are parallel and their shapes correspond to each other. Thus, key 22
The one and grooved receiving members 247, 248 provide a means to prevent relative rotation of the truss member 230 with respect to the truss member 229.

The receiving arms 235 and 236 are integral with the lower portion of the truss member 229 and extend away from the lower portion of the truss member 230. Storage arms 235 and 236
Has flanges 237 and 238, respectively, which slidably receive and support the probe cartridge 250. The lower member 228 of the truss member 239 is substantially straight but has a ridge 228 'in the center region thereof, the ridge being a series of steps 251 of the probe cartridge 250.
Is adapted to accommodate. Probe cartridge
The front portion of 250 has a shape corresponding to the shape inside the receiving arms 237, 238 and the lower member 228. in this way,
The features of the lower truss 228 and the receiving arms 235, 236 combine to form a slot between them for slidably and securely receiving the probe cartridge 250. The lower member 227 of the rear truss member 230 also has a central ridge 227 ', which is the lower truss 228 for receiving the step 251 of the probe cartridge 250.
Corresponds to the central ridge 228 '. The series of steps 251 of the probe cartridge 250 are parallel with respect to each other,
In addition, it is orthogonal to the springs 5 'to 8' and parallel to the plane of the truss member 229. When the probe cartridge 250 is assembled between the receiving arms 235, 236, the lower member 228, and the lower member 227, the probe cartridge is tightly and slidably mounted therebetween.

The adjustment member 240 is basically a longitudinal member which has a beveled tip 240 ′ at its lower end for engaging the step 251. Since the inclined tip 240 ′ is parallel to the stepped portion 251, the tip 240 ′ is fitted between adjacent ones of the stepped portion 251, and the adjusting member 240 is
When placed in position to engage 51, the probe cartridge
250 prevents further sliding. The lower end 213 of the adjustment member 240 extends at a right angle from the rest of the adjustment member 240 to provide a handle portion, which is grasped by the handle to adjust the adjustment member 24.
0 can be adjusted up and down manually. Slot 2
The mounting bolts 242 housed in 41, when the mounting bolts are completely tightened into the nuts 243, the truss members 229 of the adjustment member 240 and the probe cartridge 250
The position in the height direction relative to is fixed. Adjustment member
The vertical movement of 240 is limited by the dimensions of slot 241. When the mounting bolt 242 is loosened, the truss member 229 and
The relative movement of 230 with respect to each other is allowed and adjustment member 240 is relaxed. Thus, the adjustment member 240 can be manually adjusted in the height direction by loosening the adjustment member 240.

Fins 218, 219 integral with and extending from truss member 229 serve as a guide for the sliding movement of adjustment member 240 when mounting bolt 242 is loosened. Fins 218 and 219 guide such sliding movement of adjustment member 240 so that the longitudinal axis of adjustment member 240 is maintained perpendicular to upper surface 259 of probe cartridge 250. Further, the adjusting member 240 has a central groove 2 in its longitudinal direction.
This groove guides the sliding movement of the adjusting member 240 in a direction perpendicular to the upper surface 259 of the probe cartridge 250. The central member 268 of the truss member 229 has a greater thickness than other portions of the truss member 229. Thus, the center member 268 is raised relative to the rest of the truss member, and thus the center member 268 is
Provide an elongate guide for engaging with the groove 261 in FIG.

Next, when the mounting bolt 242 is loosened, the adjusting member 240 can be manually lifted, and its inclined tip 2 can be lifted.
The ridge 251 of the probe cartridge 250 is provided so that 40 'can slide the probe cartridge 250 in a direction perpendicular to the plate of the truss member 229 in the receiving arms 235, 236.
Release. When the probe cartridge 250 is adjusted according to the desired size of the ice bank relative to the position of the truss member 229, the adjustment member 240 is lowered again and the beveled tip 240 'reengages the ridge 251.
The distance of the springs 5 'to 8' from the truss member 229 and the distance from the cooling coil 100 between which the probe mounting means 10 'is sandwiched are adjusted to a plurality of distances, each of which is through a series of adjacent ridges 251. Tip 240 'inclined in different states
Corresponds to the combination of

Probe cartridge 250 has springs 5'-8 'projecting from distal end 252. The springs 5 'to 8' are cantilevered flat springs, but in a modified embodiment, the springs 5 'to 8' (not shown) are helical springs, which are the flat springs 5 'of this embodiment. ~
The flexibility is substantially greater than 8 '. However, the cantilevered flat springs of the springs 5 ′ to 8 ′ of the present embodiment are provided with a watertight seal that closes water leaking into a gap in the probe cartridge 250 due to connection of the springs 5 ′ to 8 ′ with the cartridge 250. Since the cartridge 250 is a flat type that can be assembled, it is used in this embodiment. The probe cartridge 250 is formed of two herbs 253, 254 which are sealed together around a spring 260 and springs 5'-8 'to form a watertight inclusion within the probe cartridge 250. Each of the springs 5 'to 8' is an insulated electrical wire within the watertight inclusion of the probe cartridge 250 in such a manner that it can be electrically operated between the circuit shown in FIG. 1 and the springs 5 'to 8'. Is connected to

Referring to FIG. 4, spring 5 'is electrically connected to line 14, like probe 5 in FIG. 1, and spring 6' is electrically connected to line 17, like probe 6 in FIG. The spring
7 'is electrically connected to the line 15 like the probe 7 of FIG. 1, and the spring 8' is connected to the line 16 like the probe 8 of FIG. Referring to FIGS. 2-4, the distal end 252 of the probe cartridge 250 has a stepped shape, with the spring 7 'connected to a step that is farther from the truss member 229 than the spring 8', and 6 'is likewise connected to a step step further from the truss member 229 than the spring 7'. Thus, when the probe mounting means 10 'is operatively clamped to the cooling coil 100 in the manner described,
The springs 5 'and 6' are in a step step farther from the cooling coil 100 than the spring 7 ', and the spring 7'
One step away from 8 '. Probe cartridge 25
The dimensions 298 and 299 shown in FIG. 4 are equal because the features of each of the 0 step steps are equally balanced. Springs 5 'and 6' project an equal distance from probe cartridge 250. Springs 5 'and 6' function as reference and ground probes 5 and 6, respectively, as described in connection with FIG. On the other hand, the springs 7 'and 8' define the sides of the ice bank and like the ice sensing probes 7 and 8 which enable the dead-band characteristics of the ice bank system. To work.

Although not shown, each electrical line 14, 1
A quick release device integrated with each end of each of 7, 15 and 16, respectively, with springs 5 'to 8' having lines 14, 17, 15 and 16
Connected to each other. Each quick release device is a spring
Spade type with one width of 5 'to 8' (spade-like)
A female member electrically connected to the male member.

Thus, each of the quick release devices causes the spring to move longitudinally therefrom when a force is exerted on each spring. The cartridge 250 is sealed to enclose the respective connection of the springs 5'-8 'in the line of the cable 260. Spring 5 '~ 8'
The electrical lines to
Collected to include zero. Since it is desired that one of the springs 5'-8 'be located, the probe cartridge 250
Can be broken and the spring can be removed from the quick release device so that the relocated spring can be inserted at the location of the removed spring. After the springs 5 'to 8' are so arranged, the springs and probe cartridge 250
The seal between them is resealed.

As shown in FIG. 2, the springs 5'-8 'have opposite protrusions of the truss members 230, so that the associated springs 5'-8' of the cooling coil 100 can be reversed in direction of protrusion. Due to the laterally symmetric outer characteristics of the probe cartridge 250, the probe cartridge 250 may be rotated about the bar 5'-8 'protruding springs 5'-8' in the opposite direction. To achieve similar results in other ways, the mounting bolts 242 of the probe mounting means 10 'may be loosened or repositioned such that the springs 5'-8' protrude in the opposite direction from the cooling coil 100. Can be removed so that can be completed.

As is clear from FIG. 3, the probe attaching means 10 '
When is mounted on the cooling coils 100 and 100 ', the probe mounting means 10' not only sandwiches the cooling coils 100 and 100 ', but the cooling coil 100 is completely surrounded by the combination of the probe mounting means 10' and the probe cartridge 250. The probe cartridge 250 can be positioned at such a position as shown in FIG. If the relative proportions of the probe mounting means 10 'are of a common size, such as a common drink dispenser, the cooling coil 100 will have a truss member 229 and 30.
Between 0 or probe cartridge 250 and cylindrical protrusion 22
Fit between 0. Additionally, if cooling coil 100 ′ is normally spaced relative to cooling coil 100, truss members 229
And 230 are a sufficient distance to sandwich the cooling coil 100 'therebetween. Such clamping in both adjacent cooling coils 100 and 100 'ensures an ideal vertical protrusion of the springs 5'-8' from a common plane for 100 'in the two cooling coils 100. Since the boundaries of the cooling coils adjacent around the ice bank typically form such parallel planes, the springs 5'-8 'ensure a vertical protrusion through the boundaries of the ice bank 99. The probe mounting means 10 'is depicted mounted on a single cooling coil at either of the locations of the cooling coils 100 and 100' as shown in FIG. Referring to FIG. 5, there is depicted a housing 300 for containing the control circuitry depicted in FIG. 1 and removably connecting these portions into an ice bank control system. Housing 3
00 is a rectangular parallelepiped including a cover 311, a side member 308, and a bottom plate 305. The upper portion 306 is plugged into the housing 300 and the housing 300 is subdivided into two circuit board housings 310 and a terminal housing 330. The upper portion 306 cooperates with both of these inclusions, but further the circuit board housing 310 is referred to as the connection between the cover 311 and the side members 308, and the terminal housing 330 is further referred to as the connection between the bottom plate 305 and the upper portion 306. Referenced. Cover 311 has four planner members 301
Are members of the side members 301-303.
303 and the member 304 is the lid member 304. The printed circuit board 320 is attached to a circuit board support plate 315. The printed circuit board 320 is electrically connected to a power supply and a sensor cable terminal by a flat pin 322. The flat pin 322 is inserted into the slot 316 of the circuit board support plate 315. Circuit board support plate 315 is inserted when circuit board support plate 315 is inserted into circuit board housing 310, for example, when tabs 312a and 312b are inserted into notches 307 and 309, respectively.
Various tabs protruding from the edge of
312 is inserted corresponding to the notch of the circuit board housing 310. The outwardly facing claws 318 couple with the circuit board support plate 315 in the middle of each of its edges. When the circuit board support plate 315 is inserted into the circuit board housing 310, for example, the claws 318a are connected to the gloves (groov) inside the side members 308.
When locked in e), the claws 318 are attached to the bottom plate 308 and the cover 3
Locked into the glove inside 11. The side members 308 of the circuit board housing 310 are held on a stop of the housing by clasps or adhesive tape. Therefore,
The end of the member 308 is the circuit board support plate 315
And removable to allow insertion of the printed circuit board 320. Terminal housing 33
0 includes a top portion 306 and a bottom plate 305. Top part 306 and bottom plate 30
The housing is shaped to receive the cable 350 via the cable slots 360, 362 when the 5 is fitted together. Three cable slots are shown in this embodiment for powering on, powering off and receiving a single sensor cable. The wires of cable 350 are attached to ribbon conductor 343 by terminal screws 341.
As shown in FIG. 8, the cable 350 is bent into an S-shape by the upper portion 306 and the ridge 339, and the ridge 333 of the bottom plate 305. This helps to prevent the cable 350 from loosening due to the disadvantageous loosening from the terminal screw 341. For each of the flat pins 322 of the printed circuit board 320,
There are corresponding ribbon conductors 343, terminal screws 341 and terminal screw posts 340. Terminal screw 431 is 7th
The terminal screw post 340 of the upper portion 306 is locked as shown in FIGS. There is a slot 335 located adjacent to each terminal screw 340 in the upper portion 306. As shown in FIG. 7 and FIG.
3 has an extension disposed in each slot 335 and connected to each terminal screw post 340. Each ribbon conductor 343
A hole through the extension of each allows the passage of a respective terminal screw 341 to clamp one wire of cable 350 against terminal screw post 340 and ribbon conductor 343. Each flat pin 322 has its own slot 3
When inserted in 35, the ribbon conductor 343
Distorted to exert a holding force on the Ribbon conductor 34
The distortion of 3 is such as to flatten as occurs in a large area of electrical contact between the pin 322 and the ribbon conductor 343.

A plurality of retaining screws 346 secure base plate 305 to upper portion 306. The retaining screw 346 is inserted through a hole 334a located in the cup-shaped recess 334 of the base plate 305 as shown in FIG. When the upper portion 306 is mounted on the base plate 305, the cup-shaped recess 334 is
5 Positioned directly in contact. As shown in FIG. 7, the retaining screw 346 is threadedly engaged with the retaining screw post 345.

After the printed circuit board 320 and the circuit board support plate 315 are mounted in the circuit board housing 310, the circuit board housing 310 is mounted on the terminal housing 330.
The flat pins 322 of the printed circuit board 320 are the terminal housing
Engage 330 slots 335. Thus, in the fully assembled portion, printed circuit board 320 is electrically connected to the appropriate terminals of terminal housing 330. The circuit board housing 310 is secured to the terminal housing 330 by a single screw 351 which is threadedly engaged in a hole 332 in the upper portion 306, as shown in FIG. Screw 351 is screw post 312 of upper flat member 304 of circuit board housing 310
Get in. Screw post 312 has hole 323 in printed circuit board 320
And through the hole 317 of the circuit board support plate 315 continuously. In this way, the printed circuit board 320 is removed from the rest of the unit without harming the cable connections in the terminal housing 330 by removing a single screw.

Also, a lens 313 is provided on the flat portion 304 at the top of the circuit board housing 310 as shown in FIG. Lens 313 is aligned with lamp 321 on printed circuit board 320. Light emanating from lamp 321 is collected and transmitted by the lens. Lamp 321 may be mounted to illuminate when an appropriate condition of printed circuit board 320 occurs. However, in a preferred embodiment, the ramp 321 is connected in series with an output contact operative to operate the compressor 101 of the ice bank cooling system as shown in FIG. As described above, the driver can easily determine whether the circuit of the printed circuit board is operating properly independently of the operation of the compressor 101.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of the system of the present invention shown with respect to an ice bank 99. FIG. 2 is an exploded view of an attachable probe of the present invention. FIG. 3 shows the second embodiment shown with respect to the cooling coils 100, 100 '.
FIG. 4 is a side view of the attachable probe of the figures. FIG. 4 is a top view of the probe attachable to FIG. 2 and is shown in operative relationship between the cooling coil 100 and the ice ridge 99, with lines 14-17 schematically shown. . FIG. 5 is an exploded view of the circuit board housing and connecting means of the present invention. FIG. 6 is a top view of the circuit board housing and the upper flat member of the connection means of FIG. 5, with cut lines corresponding to FIGS. 7 and 8 shown. FIG. 7 is a cross section of the device taken along section line 7-7 of FIG. FIG. 8 is a cross section of the apparatus taken along section line 8-8 of FIG.

Continuation of the front page (72) Inventor Milton Lloyd Chesnut, San Antonio, Deer Run, 78232, Texas, USA 1404 (72) Inventor Alfred A. Schroeder 78230, Texas, United States, San Antonio, Whisper Fountain 2811 (72) Inventor Richard O. Norman, Gate Crest, San Antonio, 78217, Texas, United States 4246 (56) References JP 49-34049 (JP, A) (JP, U) Japanese Utility Model Application Sho 57-83380 (JP, U) U.S. Pat. No. 4,182,363 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25C 1/08

Claims (11)

(57) [Claims] An apparatus for controlling the size of an ice bank surrounding a cooling coil immersed in a water bath as part of a refrigeration system, said device being immersed in said water bath and exhibiting a desired minimum size of the ice bank. A first control probe positioned at a distance from the cooling coil; a second control probe immersed in the water bath and positioned at a distance from the cooling coil indicating a desired maximum size of the ice bank; the water bath. A ground probe that is immersed in the cooling coil and is located farther from the cooling coil than the second control probe; a reference probe that is immersed in the water bath and is located farther from the cooling coil than the second control probe; Between the first control probe and the ground probe,
Between the second control probe and the ground probe,
A means for generating a constant current between the reference probe and the ground probe; a potential of the first control probe, a potential of the second control probe, and a potential of the reference probe; Means for measuring when flowing from the ground probe to the ground probe; means for turning on the refrigeration system when the potential of the first control probe is equal to the potential of the reference probe; When the potential of the reference probe is higher than the potential of the reference probe due to the formation of ice, the potential of the second control probe is kept higher than the potential of the reference probe due to the formation of the surrounding ice. Means for turning off the refrigeration system as it grows. 2. The apparatus of claim 1 further comprising means for adjusting the distance from said cooling coil in which said first control probe is located, thereby adjusting the desired minimum size of the ice bank. . 3. The apparatus of claim 2, wherein said adjusting means comprises means for allowing said first control probe to slide relative to said cooling coil. 4. The apparatus according to claim 1, further comprising: means for mutually fixing positions of the first control probe, the second control probe, and the reference probe, wherein the second control probe and the reference probe are arranged. 4. The apparatus of claim 3, wherein each distance from the cooling coil is adjusted concurrently with adjusting the distance from the cooling coil where the first control probe is located. 5. The apparatus of claim 1 wherein said means for generating a constant current generates an alternating current to minimize electro-deposition on each of said probes. 6. The measuring means further comprises means for comparing the potential of the first control probe with the potential of the reference probe, and means for comparing the potential of the second control probe with the potential of the reference probe. The device of claim 1 comprising: 7. The apparatus of claim 6, wherein both of said comparing means are electronic comparators, and wherein said refrigeration system operates in response to output signals of said two comparators. 8. An apparatus for use as part of an ice bank control system that requires a plurality of electrodes for sensing the presence of ice surrounding a cooling coil, the first sensing electrode, the second sensing electrode. A plurality of electrodes consisting of a ground electrode and a reference electrode, mounting means for mounting the first and second sensing electrodes, the reference electrode, and the ground electrode to each other and with respect to the cooling coil, The mounting means, wherein the second sensing electrode is further away from the cooling coil than the first sensing electrode, and wherein the ground electrode and the reference electrode are further away from the cooling coil than the second sensing electrode. And an adjusting means for adjusting a distance between the plurality of electrodes and the cooling coil, the adjusting means being provided in the attaching means. 9. The mounting means further comprises: a member mounted to the cooling coil defining a slot therein, a slidable cartridge received within the slot of the member,
9. The device according to claim 8, comprising: 10. The means for adjusting comprises an adjusting member movably connected to the member for releasably engaging a series of ridges formed on the cartridge, whereby the mounting means. The apparatus of claim 9, wherein said cartridge selectively prevents sliding of said cartridge with respect to said cartridge. 11. The plurality of electrodes comprises two sensing electrodes,
A reference electrode and a ground electrode, wherein the plurality of electrodes are configured such that an end of the one sensing electrode extends farther than an end of the other sensing electrode, and an end of the reference electrode and the ground electrode. 10. The device of claim 9, wherein the device is attached to the cartridge such that a. Extends further than either end of the sensing electrode.