MX2013001366A - Method and system for power control of ionic cleaners for ice machines using pulse width modulation. - Google Patents

Abstract

A method for decontaminating air in an ice making machine, comprising: controlling the level of ozone outputted from an ozone generator by modulating the voltage using pulse width modulation; and contacting the air with the ozone. Preferably, the level of ozone is about less than 0.1 ppm. The pulse width modulation controls the level of the ozone by controlling or manipulating the grams per hour of ozone introduced from the ozone generator into the ice making machine.

Description

METHOD AND SYSTEM FOR THE CONTROL OF ENERGY OF IONIC CLEANERS FOR ICE MACHINES USING WIDTH MODULATION OF PULSE Field of the Invention The present disclosure relates in general to a method and system for varying the output of an ionic cleaning device in an ice making machine based on a machine volume by means of pulse width modulation of input voltage.

Background of the Invention Ice making machines and beverage dispensing machines are susceptible to contamination by microorganisms such as bacteria, yeast, fungi, and mold. Once this equipment has become contaminated, these microorganisms can multiply and establish flowering colonies that can build up crusts in the lines, tubing, evaporator surfaces, drains and other parts of the machines. Additionally, these microorganisms can present serious damage to health for people who ingest contaminated products assorted from ice or drink machines.

The need to keep the ice maker and beverage assortment equipment clean over time is well known. Therefore, in an ice maker machine, Ref .: 238813 for example, the ice-forming evaporator, fluid lines and ice storage areas of the ice machine should be cleaned periodically. Although manual cleaning with detergents and sterilizing chemicals can be effective, cleaning programs, as a practical matter, are not always carried out thoroughly or the work is not always satisfactorily completed in terms of a deep cleaning and rinsing of all surfaces with which you have contact. Therefore, systems have been developed that include electronic controls to automatically run a sanitization cycle at set periods where the cleaning agents are pumped through the system and then rinsed. Of course, automatic systems can also fail, when, for example, the cleaning agent reservoir runs out of cleaner, or the device simply breaks down or fails to operate properly.

The use of ozone (03) as a sanitizing / oxidizing agent is well known, and especially the use of 03 to kill microorganisms in water is well known. In U.S. Pat. No. 6,153,105, Tadlock et al. Placed a Venturi in the circulating water line of an ice machine to use circulating water as a driving fluid to carry ozone from a corona discharge process to the circulating water. The corona discharge process generates ozone at a pressure below the supply pressure of drinking water to the ice machine, thus requiring the use of a Venturi. Therefore, the circulating water, with the Venturi, carries the O3 through the evaporator of the ice machine, providing a certain bactericidal or bacteriostatic effect.

Ozone can also be produced by electrolysis, which can advantageously produce ozone at pressures greater than those of the line of water circulating in the ice machine. Therefore, the ice machine would not require a Venturi or other apparatus to inject the ozone into the water line. The electrolytic production of ozone occurs in an electrochemical cell causing oxidation and reduction reactions that release or consume electrons. These reactions take place at the electrode / solution interfaces, where the electrodes must be good electronic conductors. In operation, a cell is connected to an external load or an external voltage source, and the electrons transfer electrical charge between the anode and the cathode through the external circuit. To complete the electrical circuit through the cell, there must be an additional mechanism for internal load transfer. One or more electrolytes provide internal charge transfer by ion conduction. These same electrolytes must be poor electronic conductors to avoid the internal short circuit of the cell.

Proton exchange membranes (PEMs) are a category that are particularly suitable for use in conjunction with the production of ozone in electrochemical cells. The PEMs typically have a polymer matrix with linked functional groups that are capable of exchanging cations or anions. The polymer matrix generally consists of an organic polymer such as polystyrene, or other polytetrafluoroethylene (PTFE) analog. In general, the PEM 'material is an acid with a sulfonic acid group incorporated into the matrix.

Electrocatalysts are placed in intimate contact with the ion exchange membranes. Typical electrocatalysts for an ozone generator may be lead dioxide on the anode or the ozone producing side of the cell and black platinum on the cathode side of the electrochemical cell. In many cells, hydrogen gas is generated at the cathode as a byproduct of the electrolysis reaction that produces ozone at the anode.

It is also known that ultraviolet radiation kills microorganisms in water and other liquids. Conventionally, the ultraviolet light source is a mercury vapor type lamp, which produces most of the radiated energy at a wavelength of approximately 254 nanometers, a wavelength that is known to be effective in killing microorganisms in water . The lamp may be immersed in water or liquid or the lamp may be placed adjacent to a stream of liquid flowing in a transparent conduit or in a conduit having a transparent window through which ultraviolet radiation may pass. In U.S. Pat. No. 6,153,105, Tadlock et al. Uses ultraviolet radiation to treat circulating water in an ice machine.

Although Tadlock and collaborators and others have made progress in water treatment in ice machines and beverage machines, there are still problems that need to be solved. Because water circulates through the system in the ice making machine, microorganisms have the opportunity to grow and flourish because the circulation of water provides microorganisms with the residence time required for them to multiply and establish colonies. In addition, additional microorganisms are introduced into the system each time the replenishment water fills the reservoir by batch. Consequently, water treatment must occur when the batch is placed in the tank at a fairly high speed, making the proper treatment more difficult. Treatment with ozone is difficult because the ozone source must be able to vary the speed of production of ozone in proportion to the rate of replacement of water to an adequate amount to treat the large influx of water when the batch is filled of the deposit.

What is needed is an apparatus that can treat ice making machines and stock drinks to keep them free from contamination by microorganisms. It would be an advantage if said apparatus could provide quantities of biocide disinfection according to the demand and response to the filling of a batch of the deposit. It would be further advantageous if the apparatus could provide and distribute the biocide sufficiently to prevent the growth of microorganisms through the system, including both the areas used to produce the ice or the beverage and the areas used to supply the ice or drink.

U.S. Pat. No. 7,029,587, which is incorporated herein by reference in its entirety, provides an ice machine and a method for decontaminating air. An ice machine of the present invention comprises a replacement water conduit comprising one or more ultraviolet transmission surfaces and one or more ozone injection ports and a circulating water conduit comprising one or more ultraviolet transmission surfaces. and one or more ozone injection ports. Typically, the water is circulated by means of a circulation pump from a water tank to evaporator plates. The ice machine further comprises one or more sources of ultraviolet radiation which are adjacent to the ultraviolet transmission surfaces and an ozone generator in fluid communication with one or more ozone injection ports. The sources of ultraviolet radiation can be an ultraviolet lamp that produces a greater part of its ultraviolet radiation at approximately 254 nanometers. Also, the ice machine comprises one or more controllers, wherein the controllers turn on and off one or more sources of ultraviolet radiation, the ozone generator, or combinations thereof.

Typically, the ozone injection ports are located either upstream or downstream one or more of the ultraviolet radiation sources or combinations thereof. The ozone injection ports may be located less than one pipe diameter downstream of one or more of the ultraviolet radiation sources or alternatively, less than three pipe diameters downstream of one or more of the ultraviolet radiation sources.

The ozone generator typically comprises an electrolyzer. Ozone comes out of the ozone generator as a gas, as ozonated water or as combinations of them. When the ozone generator produces gaseous ozone, the generator can further comprise at least one hygroscopic membrane, where the gaseous ozone can pass through the membrane and the water can not pass through the membrane.

The ozone generator can be in fluid communication with each of the ozone injection ports. One or more controllers to initiate and stop the generation of ozone communicate electrical signals, mechanical signals, or combinations thereof with devices such as a refrigeration compressor, a condensing fan, and / or the circulation pump.

The step of controlling the production of ozone may further comprise receiving a communication signal from the controller to drive an anode electrode against a proton exchange membrane, wherein the communication from the controller may be an electrical signal, a mechanical signal or combinations from the same . The controller may be an electrical device, a mechanical device, or combinations thereof. The controller can be a Bourdon tube, a set of bellows, or a hydraulic piston. The drive fluid for moving the controller may be a refrigerant from a compressor discharge line or pressurized water from the discharge of the circulation pump or a supply of potable water. The ozone generator is typically in fluid communication with each of one or more of the ozone injection ports.

The disadvantage of conventional ozone-generating cleaners used in ice making machines is that the typical contact of ozone with water does not sufficiently prevent the growth of bacteria in the ice maker. Others have used ozone to treat the air, however, such conventional ozone generators that have been used to treat air in ice makers receive power continuously with a DC voltage (ie, 12 volts at 600 milliamps) to energize the Ultraviolet light (UV) lamp, which in turn ionizes (by means of ozone or other ions) the air and helps with the sanitization of the food area in an ice machine. The amount of ionization depends on the amount of average energy applied to the device.

The present inventors have unexpectedly discovered that by varying the output level of an ionic cleaning device the production of excess ozone can be prevented. That is, if the level of ozone introduced in an ice machine exceeds approximately 0.1 ppm, from exposure to operate, then there may be associated potential health problems. Therefore, it would be desirable to maintain the level of ozone to which the operator is exposed during operation to less than 0.1 ppm. The present disclosure provides a method of controlling or manipulating the ozone level output amount of an ionic cleaner disposed in an ice machine by the use of pulse width modulation (PWM) from the input. DC voltage to the device. That is, the present description modulates the amount of ozone introduced into the ice machine by controlling or manipulating the grams per hour of ozone introduced from the ionic cleaner to the ice machine.

The present disclosure also provides many additional advantages, which will be apparent as described below.

Brief Description of the Invention A method for decontaminating air in an ice making machine comprises: controlling the level of ozone produced from an ozone generator by modulating the voltage using pulse width modulation; and put the air in contact with ozone.

Preferably, the ozone level is approximately less than 0.1 ppm.

The pulse width modulation controls the level of ozone by controlling or manipulating the grams per hour of ozone introduced from the ozone generator to the ice maker.

The method also includes: comparing the model of the ice maker with a search table; and determining the percentage of pulse width modulation required to control the voltage by calculating the "on" time and the frequency for a pulse width modulation exciter transistor based on the model.

The modulated voltage produced from the pulse width modulation is generated by an ozone control signal from a processor module and a pulse width modulation circuit. The pulse width modulation circuit comprises at least one exciter resistor and one field effect transistor. Preferably, the field effect transistor is a metal oxide semiconductor field effect transistor.

An ice maker machine comprises: a condenser; a compressor; an evaporator arranged in. an ice-making area; and an ozone generator in communication with the ice making zone, where the ozone level produced from the ozone generator is controlled by voltage modulation using pulse width modulation; and by contacting the air extracted from the ice-making zone with the ozone and returning it to the air-making zone.

Additional objects, features and advantages of the present description will be understood by reference to the following figures and the detailed description.

Brief Description of the Figures Figure 1 is a block diagram of a cleaner energy control used in accordance with the present disclosure; Figure 2 is a logic diagram that refers to the control of the energy used to produce ozone in an ionic cleaner by means of PWM; Figure 3 illustrates a PWM driver circuit in accordance with the present disclosure; Figure 4 is an image of an oscilloscope showing that both current and voltage vary with% PWM variation; Figure 5 is a block diagram of a microprocessor in accordance with the present disclosure; and Figure 6 is a partial rear view of the left side of the ozone generator or ionic cleaner disposed in an ice making machine in accordance with the present disclosure.

Detailed description of the invention The present disclosure includes the installation of an ionic cleaning device within an ice making machine to release an ion / ozone discharge in the food zone of the ice making machine to assist in the prolonged sanitization of the machine. The ionic cleaning device preferably uses a DC voltage energy input. In order to manipulate the ion / ozone output of the ionic cleaning device and, therefore, the ion / ozone concentration that accumulates within the ice making machine, the present disclosure contemplates the use of pulse width modulation. to control how much output the ionic cleaning device has based on what is the internal volume for the assembly of the ice maker and tank.

Pulse width modulation (PWM) is a very efficient way to provide intermediate amounts of electrical power between fully on and completely off. A simple power switch with a typical power source provides total power only when it is turned on. PWM is a comparatively recent technique and it is not known before that it has been used for the ozone supply as mentioned in the present description.

Basically, a variable power scheme of PWM is capable of switching power quickly between fully on and completely off. In any case, the switching speed is much faster than it would affect the load, ie the device that uses energy. In practice, the application of full energy during part of the time does not cause any problems.

The term work cycle describes the proportion of time on with respect to the regular interval or period of time; A low duty cycle corresponds to low energy, because the power is off for most of the time. The work cycle is expressed in percent, being 100% completely on. PW works well with digital controls, which, due to its on / off nature, can easily set the necessary duty cycle.

The PWM of a signal or power source includes the modulation of its work cycle, either to carry the information through a communication channel or to control the amount of energy sent to a load.

General digital circuits PWM signals (for example, many microcontrollers have PWM output) and usually use a counter that periodically increases (is directly or indirectly connected to the circuit clock) and which is reset at the end of each period of the PWM . When the counter value is greater than a reference value, the PWM output changes the status from high to low (or low to high). This technique is known as time dosing, particularly as a time-dosing control, whose dosage of a fixed cycle time is spent in the high state. The incremented and periodically reset counter is the discrete version of the saw waveform of the intersection method. The analog comparator of the intersection method becomes a simple comparison of integers between the current counter value and the digital reference value (possibly digitized). The work cycle can only vary in discrete steps, as a function of the counter resolution. However, a high resolution counter can provide quite satisfactory performance.

Four types of pulse width modulation (PW) are possible: 1. The center of the pulse can be set in the center of the time window and move both edges of the pulse to compress or expand the width. 2. The leading edge can be held at the front edge of the window and the rear edge can be modulated. 3. The trailing edge can be fixed and modulated the leading edge. 4. The repetition frequency of pulses can vary by the signal, and the pulse width can be constant. However, this method has a narrower range of average output than the other three.

The PWM can be used to reduce the total amount of energy delivered to a load without losses that are normally incurred when a power source is limited by resistive means. This is because the average energy delivered is proportional to the modulation work cycle. With a sufficiently high modulation rate, passive electronic filters can be used to smooth the pulse train and recover an average analog waveform.

The high frequency P M power control systems can be easily realized with semiconductor switches. The discrete on / off states of the modulation are used to control the state of the switches that correspondingly control the voltage or current through the load. The main advantage of this system is that the switches are off and do not conduct any current, or they are on and do not have (ideally) a voltage drop across them. The product of the current and voltage at any given time defines the energy dissipated by the switch, therefore (ideally) the switch does not dissipate energy. In reality, semiconductor switches such as MOSFETs or bipolar junction transistors (BJTs) do not ideal switches, but high-efficiency controllers can still be built.

During transitions between the on and off states, considerable power will be dissipated in the switches. However, the change of state between fully on and completely off is very rapid in relation to the typical on-off times, and therefore the average power dissipation is quite low compared to the power that is being supplied.

The present disclosure uses PWM as an efficient voltage regulator, in the generation of ozone from an ionic generator cleaner. By changing the voltage to the load with the appropriate duty cycle, the output will approach a voltage at the desired level. The switching noise is usually filtered with an inductor and a capacitor. A method measures the output voltage. When it is less than the desired voltage, turn on the switch. When the voltage output is above the desired voltage, turn off the switch.

The present description varies the average energy by varying the average voltage applied to the ionic cleaning device, by modulating the pulse width in the waveform of the. voltage. Preferably, the controller software automatically decides the amount of PWM based on the type of ice maker, for example, the size or capacity of the ice maker. That is, the smaller the capacity of the ice maker, the lower the average power and, therefore, the lower the PWM adjustment.

Alternatively, the PWM setting can be manually selected through the user interface as a menu item on the controller screen.

The present description can be better understood with reference to the appended figures, wherein Figures 1 and 5 illustrate the different elements / components that are involved in the control of the ionic cleaner used with an ice maker. That is, the processor module 115 preferably includes a microcontroller 105, firmware or a program 125 that has the logic to generate a control signal and also to recognize the model of the ice maker based on data entered into the controller 105 through the user interface 110 and comparing them with the model stored in the non-volatile memory 120.

The controller 105 includes a user interface 110, a processor 115 and a memory 120. The controller 105 can be implemented in a general purpose microcomputer. Although the controller 105 is represented here as a stand-alone device, it is not limited thereto, but rather can be coupled to other devices (not shown) through a network 130, if deemed necessary.

The processor 115 is configured by a logic circuit that responds to instructions and executes them.

The memory 120 stores data and instructions for controlling the operation of the processor 115. The memory 120 can be implemented in a random access memory (RAM), a hard disk, a read-only memory (ROM) for its acronyms in English), or a combination of 1 the same. One of the components of the memory 120 is a program module 125.

The program module 125 contains instructions for controlling the processor 115 to execute the methods described herein. For example, as a result of the execution of the program module 125 and the processor 115. The term "module" is used herein to denote a functional operation that can be formed either as a stand-alone component or as an integrated configuration of a plurality of components. subordinates. Therefore the program module 125 can be implemented as a single module or as a plurality of modules operating in cooperation with one another. In addition, although the program module 125 is described as installed in the memory 120, and therefore implemented in software, it could be implemented either in hardware (e.g., electronic circuits), firmware, software, or a combination thereof. .

The user interface 110 includes an input device, such as a touch screen, a keyboard or a speech recognition subsystem, to allow a user to communicate information and command selections to the processor 115.

The processor 115 pulls, towards the user interface 110, a result of an execution of the methods described herein. Alternatively, the processor 115 could direct the output to a remote device (not shown) through the network 130 such that the appropriate PWM signal is sent to control the voltage to the PWM circuit (e.g. transistors) 113 in order to modulate the voltage applied to the ionic cleaning device 114.

While the program module 125 is indicated as already loaded in the memory 120, it can be configured in a storage medium 135 for its subsequent loading in the memory 120. The storage means 135 can be any conventional storage medium that stores the module 125 programmable in it in tangible form. Examples of the storage medium 135 include a floppy disk, a compact disk, a magnetic tape, a read-only memory, an optical storage medium, a universal serial bus (USB) flash memory, a disk versatile digital, or a zip disk. Alternatively, the storage medium 135 may be a random access memory, or other type of electronic storage, located in a remote storage system and coupled to the controller 105 through the network 130.

The processor module 115 also has input / output ports, not shown, for transmitting a control signal to a driver circuit 113 located on the controller board, not shown, which in turn modulates the voltage sent to the ionic cleaning device 11. The processor module 115 generates a low voltage (3.3 V) frequency signal (1 kHz) with variable on / off times (keeping the total duration time equal), known as pulse width modulation. (PWM, for its acronym in English).

Figure 2 illustrates the logic diagram that refers "to the controller of the energy used to produce ozone in a PWM ionic cleaner in accordance with the present disclosure, wherein the ionic cleaner module is initialized or prepared 200, i.e. the configuration of the output port and the protocol of the model table is established, then the ionic device 114 is "turned on" 202, the model number entered by means of the user interface is then compared with the model table. stored in the memory 120, and based on the entered model the% of PWM 206 is adjusted by calculating the "on" time and the frequency for the exciter transistor 113. Subsequently, the process is completed 208 or it is returned to step 202; to turn on the ionic device.

Figure 3 illustrates a PWM driver circuit in accordance with the present disclosure, wherein the driver circuit, referred to herein as the PWM circuit, comprises a driver resistor 302 in a metal oxide semiconductor field effect transistor 304 that receives a control signal of the processor module 115 and converting it to a higher energy level (eg, 12 volts to 600 mA) and transmitting it to the ionic cleaning device 114.

Figure 4 is an image of an oscilloscope showing that both the current and the voltage vary when the% PWM varies, that is, the voltage varies in discrete steps from 100% to 75% of the DC of 12. volts. This is achieved by varying the "on" time of this voltage signal while maintaining the total duration of the constant signal (ie, at 1 kHz it is 1 ms).

Figure 6 illustrates an ozone generator or ionic cleaner 114 attached to the ice making machine 600 by means of a bracket securing it to the wall 604 and the left upper rail 606. The air in the ice making zone 612 it is transported to and from the ozone generator or ionic cleaner 114 through conduits or tubes 608, 610, respectively.

Although we have shown and described various embodiments in accordance with our invention, it will be clearly understood that it may be susceptible to numerous changes that are apparent to one skilled in the art. Therefore, it is not intended that it be limited to the details shown and described but is intended to show all changes and modifications that fall within the scope of the appended claims.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (14)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A method for decontaminating air in an ice making machine comprising an internal volume, characterized in that it comprises: controlling the level of ozone produced from an ozone generator by modulating the voltage using pulse width modulation based on the internal volume; Y put air in contact with ozone.

2. The method according to claim 1, characterized in that the level of ozone is approximately less than 0.1 ppm.

3. The method according to claim 1, characterized in that the pulse width modulation controls the level of ozone by controlling or manipulating grams per hour of ozone introduced from the ozone generator to the ice maker.

4. The method according to claim 1, characterized in that it additionally comprises: comparing the model of the ice maker with a search table; and determining the percentage of pulse width modulation required to control the voltage by calculating the "on" time and the frequency for a pulse width modulation exciter transistor based on the model.

5. The method according to claim 1, characterized in that the modulated voltage produced from the pulse width modulation is generated by an ozone control signal of a processor module and a pulse width modulation circuit.

6. The method according to claim 5, characterized in that the pulse width modulation circuit comprises at least one exciter resistor and one field effect transistor.

7. The method according to claim 6, characterized in that the field effect transistor is a metal oxide semiconductor field effect transistor.

8. An ice maker machine, characterized in that it comprises: a capacitor; a compressor; an evaporator disposed in an ice making zone; Y an ozone generator in communication with the ice making zone, where the ozone level produced from the ozone generator is controlled by voltage modulation using pulse width modulation based on the internal volume of the ice maker; and by contacting the air extracted from the ice-making zone with the ozone and returning it to the ice-making zone.

9. The ice maker machine according to claim 8, characterized in that the ozone level is approximately less than 0.1 ppm.

10. The ice maker machine according to claim 8, characterized in that the pulse width modulation controls the ozone level by controlling or manipulating the grams per hour of ozone introduced from the ozone generator to the ice making machine.

11. The ice maker machine according to claim 8, characterized in that it additionally comprises: comparing the model of the ice maker with a search table; and determining the percentage of pulse width modulation required to control the voltage by calculating the "on" time and the frequency for a pulse width modulation exciter transistor based on the model.

12. The ice maker machine according to claim 8, characterized in that the modulated voltage produced from the pulse width modulation is generated by an ozone control signal of a processor module and a pulse width modulation circuit.

13. The ice maker machine according to claim 12, characterized in that the pulse width modulation circuit comprises at least one exciter resistor and one field effect transistor.

14. The ice maker machine according to claim 13, characterized in that the field effect transistor is a metal oxide semiconductor field effect transistor.