ENERGY SAVER CYCLE

Info

Publication number: 20160208428
Type: Application
Filed: Dec 21, 2015
Publication Date: Jul 21, 2016
Inventor: Victor Hugo Miranda Razo (Santiago de Queretaro)
Application Number: 14/976,550

Abstract

Embodiments are related to a drying procedure and a household appliance for drying textile items, and more particularly to a dryer using controls based on a processor in order to control the drying operation making an efficient use of the heat source (electrical or gas), evaluating various parameters as temperature, time and humidity level in predetermined ranges.

Description

Description

FIELD OF THE INVENTION

Embodiments are related to a household appliance for drying textile items, and more particularly to a dryer using controls based on a processor in order to control the drying operation making an efficient use of the Heat Source (electrical or gas), evaluating various parameters such as temperature, time and humidity level in predetermined ranges.

DESCRIPTION OF THE PREVIOUS ART

Usually, a dryer is provided for drying a wet object (e.g., wet textiles). Hereinafter, the wet objects will be known as “textiles” or “clothes” without exclusive limitation to these.

A common practice is to detect the humidity level of the textiles in a rotating drum using humidity sensors provided in a lint duct and/or an exhaust duct. A voltage signal from the humidity detector is used for estimating the humidity content of the items being dried, based on the composition characteristics of the textiles load. That is, an electric resistance measurement generated when the clothes contact the sensor bars is used; if the clothes have water within their fibers, a signal will be emitted, whereas if the clothes are dry and/or do not have water, said bars saturate the operating range and, therefore, the signal will no longer be reliable. The detectors signal is periodically monitored by means of voltage values that are filtered, cleaned and entered into a processor having a module in order to determine when the clothes are wet, dry or very dry based on a humidity contents target level.

When the clothes are almost dry, or when the textiles load is small, the effectiveness of the sensor for accurately determining the humidity contents of the textiles being dried is reduced and common in this type of measurements, as it loses sensibility. Therefore, the humidity sensor voltage signal can vary greatly throughout the drying time and maybe does not accurately reflect the humidity contents of the textiles or items being dried. The textiles or items can, occasionally, contact the humidity sensor's electrodes and sometimes not be in contact with the electrodes, given generally random rotation patterns of the textiles and small loads.

As it can be supposed, another factor affecting the detector's precision for detecting the humidity content occurs when the textiles are not dried evenly. That is, some parts of the textiles can be wetter than other parts of the textiles, and the wetter parts could not be detected with precision by the sensors.

In this manner, in order not to have wet clothes at the end of the cycle, the dryer must extrapolate the drying time after the humidity level where the sensor's sensibility is lost, adding the drying time. The risk in energy saving drying cycles is that it does not sufficiently dry the textiles due to the added time is not adequate, or it takes more time and consequently increases the drying cycle energy consumption. Thus, a processor must be provided for calculating and compensating times in a precise manner and predicting the drying time needed by the drying cycle. Therefore, the problem is to provide the dryer with the flexibility to adjust the cycle time as a function of certain factors, as the type and size of the load, the restriction of the System directly observed in the voltage signal and the multiplier and additional times in order to reach the final humidity target. The benefit of the problem to be solved is to have dry clothes at the end of the drying cycle, according to the predetermined heat level or the heat level selected by the user, according to the predetermined cycle or the cycle selected by the user, the load quantity, the restrictions and the energy level, allowing a lower level of energy consumption and the user satisfaction due to a proper drying of the textiles in the dryer.

There are processes known in the art for determining certain aspects of the drying in a dryer. For instance, Chinese Patent No. 1 715 544 reveals a control method for regulating the heater and the fan based on the drum's internal conditions, such as temperature and humidity for allowing a microprocessor to regulate the heater and the fan, allowing to shorten the drying period.

The Spanish Patent No. 2 212 436 reveals a procedure for monitoring the flow speed of a process air current generated by a fan in an air channel and heated by a heating system in a domestic clothes dryer where the process air temperature is measured at least in one point located in the current's direction, after the heating system, characterized in that the heating system's heating power varies, the temperature variation thus produced is measured in the process air current at least in one point, and the difference between these moments where the process air current temperature variation is measured at a first place or a second place, respectively, or between the moments where the heating power variation or the process air current's temperature variation is measured at a second place, and it is used as a measurement of the process air current flow speed.

The Japanese publication JP 1131699 reveals that a semiconductor heater's energy source is a constant voltage energy source; the energizing is controlled for setting the heater's energy consumption. When the dryer finishes, the heater is turned off in order to stop the dryer's motor. Under control, the current energy consumption is maintained at a desired energy consumption by the control phase through the room temperature, etc. varies, the energy consumption is constant. After, when it is controlled in order to maximize the allowed energy consumption in a determined condition, the heater is always operated at the maximum energy consumption with no relation to the room temperature variation. As a result, the heater's capacity is always extracted at a maximum for reducing the clothes drying time.

The Japanese publication JP 2005245489 reveals that the dryer is provided with a rotating drum, an air intake section with a heater, an exhaust section with a fan, an exhaust temperature sensor located in the exhaust section and a controller which controls heat. Clothes are dried adjusting the exhaust air temperature at a preset temperature, having as input the exhaust air temperature detected by the temperature sensor in the controller and controlling the heater. The clothes drying process controlling the dryer is comprised by a multiple drying duration number with a prescribed temperature which is sequentially low and the drying time for each drying duration is predetermined. It is desirable that the temperature set for the last drying period is approximately similar to the cooling temperature required during the cooling process.

The U.S. Pat. No. 5,454,171 reveals a dryer including a drum containing the clothes to be dried, a heater and a fan for providing hot air in the drum during the drying operation, and a temperature sensor detecting the temperature in the drum. The drying operation includes a drying step where the hot air is provided to the drum and a cooling step where the heater is disconnected. The intermittent operation is started when the drying operation is completed. The intermittent operation is completed when the temperature detected by the temperature detector has reached a preset value in order to prevent the clothes from wrinkling.

The U.S. Pat. No. 6,199,300 reveals a method and apparatus for controlling the heat intake of a dryer where the initial heat for a load of clothes is set on maximum power until a predetermined temperature or time condition occurs. The dryer's heat intake is reduced in order to lower the energy consumption while the clothes load humidity is effectively removed. When the clothes load humidity content falls within a predetermined quantity, the maximum heat intake is applied again for remove the remaining humidity in the clothes load.

The U.S. Pat. No. 6,700,102 reveals a control circuit operating with a 120 volts power supply which compensates for changes in room temperature for compensating a premature advance of the dryer's motor chronometer during an automatic drying cycle.

The U.S. Pat. No. 6,822,201 reveals a dryer having a heater control circuit for controlling the impulse of a dryer using one of a plurality of high voltages, which uses a circuit made by a kind of “C” contact relay provided between a microcomputer output and a plurality of heater drivers, in order to ensure the heater's impulse capacity is ensured, even when the current output fails, and to avoid short circuit conditions even when the microcomputer has logical malfunctions.

The United States Patent publication US 2007/0251119 reveals a dryer and a control method for the same, by which energy saving maintenance and optimal temperature within the drum are enabled in a manner such that diversifies the heater's temperature, varying the rotational speed of the fan used by the dryer. A drying drum is included to contain an object to be dried, a fan provided for enabling air passing through the drying drum, a heater for heating air supplied to the drying drum, an impulse motor which generates an impulse force for rotating the drum and fan and a control unit which controls the impulse motor's RPMs in order to varying according to the result detected by the temperature sensor.

The U.S. Pat. No. 7,322,126 reveals a clothes dryer having a dryness level control system which is responsive to the clothes items humidity rotating within a drum and a target humidity objective for controlling the drying cycle of the dryer. The dryer has a load size parameter producing module and an air flow detection parameter module. These two modules generate one of two parameters conditions used by the processor in order to modify or select an adequate humidity target value. The target size parameter producing module generates a small load parameter and a big load parameter. The air flow detection module produces a first or a second air flow parameter to be used in the dryness level processor. As a result, the processor selects one of the four humidity values for these conditions.

MABE's Patent Application MX/a/2010/008115 reveals a method for compensating the drying time by which several factors are measured, such as drying level, minimum drying time, size and weight of the clothes load, and ranges for the humidity and temperature level reached during the drying process, in order to achieve a compensation in the drying time and energy consumption, operating at high or medium temperatures in order to reduce the drying cycle. Nevertheless, energy savings are at a low level and the energy savings cannot be regulated.

The document US 2012/0084995 reveals a clothes drying method which uses a time given by the operator and the dryer uses said time as a predetermined operating time, nevertheless an energy savings process is not established during said operating time.

Application US 2013/0167398 describes a textile drying process, where it operates a first drying temperature or a second drying temperature greater than the first according to a reference value, and depending on the material to be dried. Nevertheless, energy savings are not mentioned in the drying process.

In this manner, the need exists in the art for the textiles drying equipment to save energy without losing efficiency, nor having long operation periods sacrificing drying speed. In this manner, embodiments provide an equipment and method for drying textiles which allows saving energy without the inconvenience of the previous art.

BRIEF DESCRIPTION

Usually, dryers comprise a humidity detector, which is used for measuring and predicting the humidity content percentage or dryness level of the items within the container. The humidity detector usually comprises a pair of spaced bars or electrodes and also comprises circuits for providing a voltage signal representation of the humidity content of the items to a controller based on the electrical or ohmic resistance of the items, the humidity evaluation is based on the resistance produced during contact of the textiles with the electrodes.

Contact duration between textiles and detector electrodes depend on various factors, as the rotational drum speed, the type of textile, the quantity or volume of clothes in the drum and the flow of air through the drum. When wet textiles are inside the dryer's drum and in contact with the sensor's electrodes, the electrical resistance measured through the sensor is low. When textiles are dry and in contact with the sensor's electrodes, the electrical resistance detected through the sensor is high and indicative of a dry load. Nevertheless, situations can occur which result in erroneous indications of the current level of dryness of the items. For instance, in a situation when the wet textiles are not in contact with the humidity detectors, as in a small charge, the resistance through the sensor is very high (open circuit), which would be a false indication of a dry load. Additionally, if a conductive part of dry textiles, e.g., a metallic button or zipper, is in contact with the sensor's electrodes, the sensor's resistance would be low, which would be a false indication of a wet load. Thus, when the textiles are wet, it is sometimes possible for the sensor to erroneously detect a dry condition (high resistance) and, when textiles are dry, it is sometimes possible that the sensor erroneously detects a wet condition (low resistance).

The noise reduction and insulation are provided by a controller leading to a more precise and reliable detection of the current dryness condition of the items and results in a more precise and reliable control of the dryness operation. Nevertheless, the noise reduction per se does not completely compensate the variations in load size or different dryers having air flow restrictions due to different ventilation.

The electronic controller responds to a voltage signal from the humidity detector and predicts a humidity contents percentage or dryness level of the items within the container as a function of the resistance of the items. As previously suggested, the voltage signal value supplied by the humidity sensor is related to the textiles humidity contents.

The electronic controller is also connected to an input temperature sensor, such as, for instance, a thermistor. The input temperature sensor is mounted on the drier in the air flow, preferably entering the drum. The input temperature sensor detects the temperature entering the drum and sends a temperature signal corresponding to the electronic controller. The electronic controller is connected to the output temperature sensor, which detects the temperature of the air exhausted from the drum and sends a temperature signal corresponding to the controller. The electronic controller interprets these signals in order to generate an air flow parameter based on the input temperature increase and/or a load size parameter based on the increase of the output temperature. These parameters, among others, are used for selecting a target humidity signal, which in turn is used by a controller jointly with the filtered and/or reduced voltage signal of the humidity sensor noise in order to control the dryer's operation, for obtaining a target voltage or target humidity signal.

The controller comprises an analog to digital (A/D) converter in order to receive the signal representations sent from the humidity sensor. The signal representation of the A/D converter and a counter/timer is sent to a central processing unit (CPU) for a greater signal processing than described below in more detail. The CPU also receives the input and output temperature, respectively, from the temperature sensors, via two different analog to digital converters (A/D). The CPU receiving energy from a power source, comprises one or more processing modules stored in an adequate memory device, as a read-only memory or ROM, in order to predict a humidity percentage content or dryness level of the textile items in the container as a function of the electrical resistance of the items, as well as for processing the elapsed time and adding an additional time. Once it has been determined that textile items have reached a desired dryness level, then the CPU sends respective signals to an input/output module, which in turn sends respective signals to de-energize the motor and/or the heating medium. An electronic interface and display panel allows an user to program the dryer's operation and also allows monitoring the progress of the respective operating cycles of a dryer.

CPU and ROM can be configured for comprising a dryer's processor. The processor estimates the stopping time and controls the dryer's stopping based on a humidity signal received from the humidity sensor, in the elapsed time and the additional time. The processor filters the humidity signal, this can be a voltage signal and compares this with the target humidity in order to control the dryer's operation. The processor selects a target voltage or target humidity signal, from a target humidity signal table.

When textiles are in contact with the sensor's electrodes and voltage drops through the sensor's electrodes, therefore decreasing to a lesser value indicative of the textiles humidity content. Nevertheless, if the textiles are not in contact with the sensor's electrodes for a prolonged time period overlapping the postponed response time associated with the detector's electrodes, then the signal lecture does not reach its stable value condition. For small loads, it can be observed than the minimums are farther from the load's actual humidity level as compared to the curve's greater loads. Nevertheless, the slope of the curve immediately before the minimum for small loads is usually more than the heavier loads. The electronic controller and/or the processor detect the voltage signal minimums from the electrodes sensor and the immediate gradient before the minimum. The processor and/or controller use this information for extrapolating the predicted humidity signals for each minimum and/or maximum. When the result is that the voltage signal is equal to, or during a determined time an average equal to the target voltage, this information is extrapolated for adding a determined extra time. The processor calculates and compensates times and sets the additional drying time needed by the drying cycle.

Therefore, a drying method exists where during the drying cycle the cycle's additional drying time can be estimated and thus adjusted in order to provide an adequate and even drying of the textiles.

Surprisingly, it has been demonstrated that the heat produced during the dry cycle is not made the most of during drying or in order to achieve an adequate drying, as during the drying cycle there is a heating stage, an evaporation stage and overheating can occur, and it has been demonstrated that not all the heat provided during these stages is properly used, therefore substantial energy savings can exist during the textile garments drying cycle, as overheating must be avoided and it has been demonstrated that not all the heat supplied during these stages is properly used, therefore substantial energy savings can exist during the textile garments drying cycle, particularly in evaporation and overheating. During the dehydration or evaporation of the textile garment, it is not necessary for the heaters to operate at all times, as surprisingly it has been discovered that the power level required can additionally be modulated or regulated in order to achieve additional energy savings.

In this way, an embodiment proposes a drying method for the cases where the user determines an energy saving cycle, which not only determines an additional drying time, but additionally a temperature estimation and humidity level exist, in order to more precisely determining an effective drying cycle that allows having energy savings during drying. This is independent of selecting a drying method where a high or medium heat level must exist, or in case of low or too low heat levels.

Additionally, an embodiment proposes a drying method for the cases in which the user determines that a low or very low heat level needed for the drying must exist, for instance drying delicate textiles, by which not only an additional drying time is determined, but additionally a temperature and humidity level estimation exists in order to more precisely determining an effective drying cycle.

An embodiment has as an objective to control the heater or a plurality of heaters in the dryer, which in total add up to 100% of its power, these heaters can be controlled individually or jointly during the drying cycle in order to be able to freely select the power level used for the heaters, according to need based on the humidity level required, in order to decrease power consumption and the drying cycle time.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects will be evident when the following description is taken into account in correlation with the figures detailed below:

FIG. 1 shows a conventional perspective view of a dryer.

FIG. 2 shows a block diagram of a controller system which can be adopted by an embodiment disclosed herein.

FIG. 3 shows a block diagram of the processor and the parameter generating modules of an embodiment disclosed herein.

FIG. 4 shows a diagram representative of the voltages obtained by the humidity sensor.

FIG. 5 shows a flowchart of a drying time compensation method according to an embodiment disclosed herein.

FIG. 6 shows a flowchart of the drying power modulation method according to an embodiment disclosed herein.

FIG. 7 shows a diagram of the drying power modulation method according to an embodiment disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments are related to a drying method, and particularly to a drying method, preferably, but not limited to, a textiles domestic dryer which allows the flexibility of adjusting cycle times for the dryer, preferably drying times as a function of the selected heat levels, as well as allowing substantial energy savings as a function of time.

Definitions:

The use of the term “approximately” provides an additional determined range. The term is defined as follows. The additional range provided by the term is approximately ±10%. As an exemplary, but not limitative manner, if “approximately between 30 to 40 seconds” is stated , the exact range is between 27 and 44 second, or between 33 to 44 seconds, or between 33 to 36 seconds. Any of the previously described possibilities is covered by the term “approximately”.

The term “Aggregated” refers to a time value predetermined in a table, where the aggregate is a function of the type of dryer (gas or electrical), the cycle type, the drying level, the load and the restrictions.

The term “Bone Dry” is a term used in the art for the dry weight of the textiles.

The term “Raw Voltage Squares” refers to the total sum of the squares obtained by the raw voltage descriptive statistics chart.

The term “Load State” refers to a value determining the load state of the textiles within the drum.

The term “Heat Factor” refers to a factor as a function of the heat level selected by user and cycle type.

The term “FMC” refers to the water percentage remaining in the textiles, that is, the final humidity content (Final Moisture Content).

The term “Samples” refers to the total sum of the raw voltage squares specimens available.

The term “Multiplier” refers to a value predetermined in a table, related to the final drying time expression, where the multiplier is a function of the type of dryer (gas or electrical), the cycle type, the drying level, the load and the restrictions.

The term “heat level” is a parameter selected by the user.

The term “Restriction” refers to the possible restrictions found in the humid air exhaust coming from the drum's interior to the exterior. Among the possible restrictions are the exhaust duct diameter, the exhaust duct length, the exhaust duct height, obstructions, etc.

The term “additional time” or “extra time” is the time the minimum time for the drying cycle is extended in order to dry the load within the dryer's drum.

The term “minimum drying time” or “minimum time” is the minimum time calculated based on tests and preset that the dryer must remain turned on in order to achieve a target drying level, which is a function of the cycle type, drying level, load weight and restrictions.

The term “Trtv” (Time to Reach Target Value) is the drying cycle's elapsed time for achieving the preset target voltage.

The term “cycle time” is a parameter selected by the user.

The term “raw voltage” refers to the voltage without any signal conditioning or signal digital processing, but the simple acquisition of the voltage being measured.

The term “filtered voltage” refers to the voltage with signal conditioning and/or signal digital processing.

The term “target voltage” is a voltage measured by humidity sensors, which will be explained in more detail in the following detailed description of the invention.

The term “Current temperature” is the temperature level within the dryer's drum, it must preferably be within the temperature range.

The term “Temperature range” is a temperature interval that establishes an acceptable temperature level during the drying cycle, it is defined between the restart temperature and the cutoff temperature.

The term “restart temperature” is the temperature level that delimits the lowest acceptable temperature within the temperature range for the drying cycle, therefore, being in a lower heat level indicates that the temperature has decreased excessively and must be increased.

The term “cutoff temperature” is the heat level the limiting the highest acceptable temperature within the temperature range for the drying cycle, therefore, being at this heat level or at a higher heat level indicates that overheating occurs and the temperature must be decreased.

The term “heater” refers to the element used in order to increase the temperature within the dryer's drum, that for gas dryers is known as burners, or for electrical dryers is known as resistance.

The usual layout for a dryer will be described below. This layout may change and it is not exclusive to the following description, it must be taken in an illustrative manner and not as a limitation of an embodiment disclosed herein.

FIG. 1 shows a conventional perspective view of a textiles dryer 10 which can benefit from an embodiment disclosed herein. The dryer can include a case or main housing 12, a front panel 14, a back panel 16, a pair of side panels 18, 20 spaced between them by the frontal and back panels and a top cover 24.

Within the housing 12 there is a drum or container 26 mounted for rotating around a substantially horizontal axis. A motor 44 rotates the drum in the horizontal axis by means of a transmission, for instance, a pulley 43 and a belt 45. The drum has a generally cylindrical form, it has an outer perforated cylindrical wall 28 and its front is closed by a wall 30 defining an opening 32 in the drum 26. Clothing and other textiles can be introduced within the drum 26 through the opening 32. A plurality of tumbling ribs (not shown) are provided within the drum for rising the items deposited within the drum and then allowing them to tumble back to the bottom part of the drum while the drum rotates. The drum 26 includes a back wall 34 supported in a rotating manner within the main housing 12 by means of an appropriate fixed bearing. The back wall 34 includes a plurality of holes 36 which receive hot air that has been treated by a heating medium, such as a combustion chamber 38 and back duct 40. The combustion chamber 38 receives ambient air via an intake 42. Even when the example dryer 10 shown in FIG. 1 is a gas dryer, the option for an electrical dryer having resistance heating elements located in the heating camber positioned besides the perforated outer cylindrical wall 28 which would replace that combustion chamber 38 and the back duct 40 in a gas dryer must be also considered. The heated air is sucked in from the drum 26 by a fan 48, which in turn is driven by the motor 44. The air passes through a filter screen 46 that catches any type of particulate matter. While the air passes through the filter screen 46, it enters a trap duct seal 48 and is exhausted out of the clothes dryer through an exhaust duct 50. After the items have been dried, they are removed from the drum 26 via the opening 32.

In an exemplary embodiment of this invention, a humidity sensor 52 is used in order to predict the humidity content percentage or dryness level of the items within the container. The humidity detector usually comprises a pair of spaced bars or electrodes and also comprises circuits for providing a voltage signal representation of the humidity content of the items to an electronic controller 58, based on the electrical or ohmic resistance of the items. The humidity detector 52 is located on the inner front wall of the drum, and alternatively it is mounted on the back of the drum's wall when this wall is static. In some instances, the humidity detector has been used in a contained in the dryer's drum. As an example, but not in a limitative manner, the detector signal can be chosen for providing a continuous representation of the humidity contents of the items in a range, suitable for processing the electronic controller 58. It can be appreciated that the signal indicating the humidity contents does not need to be a voltage signal ad, for instance, through the use of an oscillator-controlled voltage, the humidity indication signal could have been selected as a frequency signal that varies proportionally to the humidity content of the items due to a signal whose voltage level varies proportionally to the humidity content of the items.

The textiles being in the drum 26 of the dryer randomly contact the static humidity sensor 52 spaced electrodes, so the textiles are intermittently in contact with the sensor electrodes. Contact duration between textiles and detector electrodes depend on various factors, such as the rotational drum speed, the type of textile, the quantity or volume of clothes in the drum and the flow of air through the drum. When wet textiles are inside the dryer's drum and in contact with the sensor's electrodes, the resistance through the sensor is low. When textiles are dry and in contact with the sensor's electrodes, the resistance through the sensor is high and indicative of a dry load. Nevertheless, situations can occur which result in erroneous indications of the current level of dryness of the items. For instance, in a situation when the wet textiles are not in contact with the detectors, as in a small charge, the resistance through the sensor is very high (open circuit), which would be a false indication of a dry load. Additionally, if a conductive part of dry textiles, e.g. a metallic button or zipper, is in contact with the sensor's electrodes, the sensor's resistance would be low, which would be a false indication of a wet load. Thus, when the textiles are wet it is sometimes possible that the sensor erroneously detects a dry condition (high resistance) and, when the textiles are dry, there can be times when the sensor erroneously detects a wet condition (low resistance).

Thus, the noise reduction and insulation are provided by an electronic controller 58 leading to a more precise and reliable detection of the current dryness condition of the items and results in a more precise and reliable control of the drying operation. Nevertheless, the noise reduction per se does not completely compensate the variations in load size or different dryers having air flow restrictions due to different ventilation.

The electronic controller 58 responds to a voltage signal of the humidity sensor 52 and predict a humidity content percentage or dryness level of the items in the container as a function of the items resistance. As previously suggested, the voltage signal value supplied by the humidity sensor 52 is related to the textiles humidity contents. For instance, at the beginning of the cycle when the textiles are wet, the humidity sensor voltage can be within the range of one or two volts. For instance, while textiles dry, the humidity sensor 52 voltage can increase a maximum of approximately five volts.

The electronic controller 58 is also connected to an input temperature sensor 56 , such as, for instance, a thermistor. The input temperature sensor 56 is mounted on the dryer 10 in the air flow entering the drum 26. The input temperature sensor 56 detects the temperature entering the drum 26 and sends a temperature signal corresponding to the electronic controller 58. The electronic controller is also connected to the output temperature sensor 54, which detects the temperature of the air exhausted from the drum 26, and sends a temperature signal corresponding to the electronic controller 58. The electronic controller 58 interprets these signals in order to generate an air flow parameter based on the input temperature increase and/or a load size parameter based on the increase of the output temperature. These parameters, among others, are used for selecting a target humidity signal, which in turn is used by a controller 58 jointly with the filtered and/or reduced voltage signal of the humidity sensor 52 noise in order to control the dryer 10 operation, for obtaining a target voltage signal.

A more detailed illustration of the electronic controller 58 is shown in FIG. 2. The electronic controller 58 comprises an analog to digital (A/D) converter 60 in order to receive the signal representations sent from the humidity sensor 52. The signal representation of the A/D converter 60 and a counter/timer 78 is sent to a central processing unit (CPU) 66 for a greater signal processing that is described below in more detail. The CPU 66 also receives the input and output temperature, respectively, from the temperature sensors 56 and 54 respectively, via two different analog to digital converters (A/D) 62 and 64. The CPU 66 receiving energy from a power source 68, comprises one or more processing modules stored in an adequate memory device, as a read-only memory (ROM) 70, in order to predict a humidity percentage content or dryness level of the textile items in the container as a function of the electrical resistance of the items, as well as for processing the elapsed time and additional time. It can be appreciated that the memory device not necessarily is limited to the ROM memory, and it is possible that any other memory device, e.g. an erasable programmable read only memory (EPROM) storing instructions and data also works effectively. Once it has been determined that textile items have reached a desired dryness level, then the CPU sends respective signals to an input/output module 72, which in turn sends respective signals to de-energize the motor and/or the heating medium. While the drying cycle is turned off, the controller can activate a buzzer via a buzzer enabling/disabling circuit to indicate the end of the cycle to the user. An electronic interface and display panel 82 allows an user to program the dryer's operation and also allows monitoring the progress of the respective operating cycles of a dryer.

The CPU 66 and the ROM 70 can be configured as shown in FIG. 3 in order to comprise a dryer's processor 90. The processor 90 estimates the stopping time and controls the dryer 10 stopping based on a humidity signal 52A received from the humidity sensor 52, in the elapsed time and the additional time. The processor 90 filters the humidity signal or voltage signal, and compares this against the target humidity or target voltage in order to control the dryer 10 operation. Many common systems and methods exist for filtering the humidity signal.

According to an embodiment disclosed herein, the processor 90 selects a target voltage or target humidity signal, from a target humidity or target voltage signal table 92.

Referring to FIG. 4, two curves 82 and 84 are shown, which indicate the raw voltage signal detected by the humidity detectors 52 during the drying cycle, according to an embodiment where the raw voltage signal provided by sensor 52 and its associated circuitry has a lesser value for wet textiles and a greater value for dry textiles. Curve 82 represents a curve indicating a big load. Curve 84 is in nearer to the actual humidity content of the textiles in the dryer than curve 82 due to a greater number of textiles in contact with the bars or electrodes of the sensor during the drying process. When textiles are in contact with the sensor's electrodes 52 and voltage drops through the sensor's electrodes, therefore decreasing to a lesser value indicative of the textiles humidity content. Nevertheless, if the textiles are not in contact with the sensor's electrodes for a prolonged time period overlapping the postponed response time associated with the detector's electrodes, then the signal lecture does not reach its stable value condition.

FIG. 4 shows that the curves 82, 84 have a series of maximum 88 and minimums 90. For small loads, the minimums 90 are farther from the load's actual humidity level as compared to the greater loads in curve 84. Nevertheless, the slope of the curve immediately before the minimum 90 for small loads is usually more than the heavier loads. An embodiment provides the electronic controller 58 and/or the processor 90 in order to detect the voltage signal minimums 90 from the electrodes sensor and the immediate gradient before the minimum. The processor and/or electronic controller 58 use this information for extrapolating the predicted humidity signals for each minimum and/or maximum. When the result is that the voltage signal is equal to, or during a determined time an average equal to the target voltage, this information is extrapolated for adding a determined extra time.

The effectiveness of the humidity sensor 52 for determining the humidity content of the load being dried is an important factor in the drying detection.

With the objective of not having wet parts of the load at the end of the drying, the dryer 10 extrapolates the drying time after the voltage signal obtained from the humidity sensor 52 has been equaled to the target voltage, which represents the level where the humidity sensor 52 loses sensibility.

The risk in energy saving drying cycles is that the load is not sufficiently dried because the minimum time or the Trtv is not adequate, and similarly the additional time is longer and, consequently, consumes more power than that needed for drying. The risk in high energy saving drying cycles is that the load is dried excessively due to the additional time not being adequate, thus shrinking the load.

Thus, the processor 90 must calculate and compensate times in a precise manner and predict the minimum drying time and the additional time. Therefore, the problem is to provide the dryer 10 with the flexibility to adjust the cycle time by means of the calculation of the target voltage and the minimum time as a function of the aforementioned factors, such as the type of dryer, the drying level, the restrictions, the cycle type and the load weight, among other factors; as well as by adjusting the cycle time by means of calculations of the additional time as a function of the aforementioned factors, such as the heat factor, the type of dryer, the minimum time, the Trtv, the multiplier and the aggregate. The benefit of the problem to be solved is to have dry clothes at the end of the drying cycle, independently of the predetermined heat or the heat selected by the user, allowing the use of the lowest level of power consumption possible and the user satisfaction due to a correct drying of the load of the dryer 10.

Thus the drying cycle of an embodiment allows to determine with a greater precision that additional time for the cycle as a function of the heat factor in order to provide an adequate and even drying for the load.

In this manner, the drying time compensation method 110 for a textiles dryer starts in 130, the drying cycle, once the user has selected in 120, from the control panel 82 of the dryer, a desired cycle type and drying level of the clothes. Once the cycle is started, in 140 the load size and the type of restrictions on the dryer are determined by means of the electronic controller 58 and/or CPU 66. Once said values have been determined and all the previous data (cycle type, drying level, load weight and restrictions) are available, in 150 the “target voltage” and the “minimum cycle time” are established as a function of the same and according to the type of dryer, according to the following predetermined values table:

TABLE (I) Final Desired Drying DOD dryness Target Time Minimum Profile level Restriction Weight voltaje Expression A Time Electrical Wet Small Small 3.10-3.35 0.50-1.50 0-3 10-14 or gas Big 2.15-2.45 0.50-1.50 0-3 23-27 Cotton Big Small 3.25-3.55 0.50-1.50 0-3 9-13 DOD Big 2.15-2.45 0.50-1.50 0-3 12-16 Less Dry Small Small 3.20-3.50 0.50-1.50 0-3 18-22 Big 3.10-3.35 0.50-1.50 0-3 28-32 Big Small 3.35-3.60 0.50-1.50 0-3 15-19 Big 3.15-3.45 0.50-1.50 0-3 24-28 Dry Small Small 2.60-2.90 0.50-1.50 17-23 32-36 Big 2.90-3.20 0.50-1.50 15-20 32-36 Big Small 3.25-3.55 0.50-1.50 12-17 25-29 Big 3.25-3.55 0.50-1.50 10-15 31-35 Drier Small Small 3.35-3.60 0.50-1.50 20-25 30-34 Big 3.40-3.70 0.50-1.50 20-25 37-41 Big Small 3.15-3.45 0.50-1.50 20-25 32-36 Big 3.15-3.45 0.50-1.50 17-23 34-38 Electrical Wet Small Small 3.15-3.45 0.50-1.50 0-3 11-15 or gas Big 3.30-2.60 0.50-1.50 0-3 18-22 Mixed Big Small 3.20-3.50 0.50-1.50 0-3 8-12 load DOD Big 1.90-2.15 0.50-1.50 0-3 17-21 Less Dry Small Small 3.50-3.80 0.50-1.50 0-3 13-17 Big 3.45-3.75 0.50-1.50 0-3 28-32 Big Small 3.50-3.80 0.50-1.50 0-5 11-15 Big 3.50-3.80 0.50-1.50 0-3 18-22 Dry Small Small 3.45-3.75 0.50-1.50 12-10 22-26 Big 3.45-3.75 0.50-1.50 10-15 19-23 Big Small 3.25-3.55 0.50-1.50 12-18 26-30 Big 3.25-3.55 0.50-1.50 10-15 27-31 Drier Small Small 3.50-3.80 0.50-1.50 20-25 16-20 Big 3.45-3.75 0.50-1.50 27-22 16-20 Big Small 3.20-3.50 0.50-1.50 20-25 22-26 Big 3.45-3.75 0.50-1.50 15-20 26-30 Electrical Wet Small Small 2.90-3.20 0.50-1.50 0-3 11-15 or gas Big 1.30-1.60 0.50-1.50 0-3 18-22 Easy care Big Small 2.30-2.60 0.50-1.50 0-3 12-16 DOD Big 1.15-1.40 0.50-1.50 0-3 13-17 Less Dry Small Small 3.40-3.65 0.50-1.50 0-5 13-17 Big 3.40-3.65 0.50-1.50 0-3 24-28 Big Small 3.30-3.60 0.50-1.50 0-3 14-18 Big 2.30-2.60 0.50-1.50 0-3 17-21 Dry Small Small 3.50-3.75 0.50-1.50 10-16 22-26 Big 3.55-3.80 0.50-1.50 10-15 15-19 Big Small 3.15-3.40 0.50-1.50 10-18 25-29 Big 3.10-3.35 0.50-1.50 5-10 21-25 Drier Small Small 3.40-3.70 0.50-1.50 20-25 17-21 Big 3.30-3.55 0.50-1.50 17-22 17-21 Big Small 3.10-3.35 0.50-1.50 20-25 28-32 Big 3.40-3.70 0.50-1.50 5-10 16-20 Electrical Wet Small Small 2.60-2.85 0.50-1.50 0-3 26-30 or gas Big 2.25-2.55 0.50-1.50 0-5 28-32 Active Big Small 2.80-3.10 0.50-1.50 2-7 27-31 Drying Big 2.35-2.65 0.50-1.50 0-3 25-29 DOD Less Dry Small Small 1.85-2.15 1.50-2.50 26-31 22-26 Big 3.35-3.60 0.50-1.50 0-3 28-32 Big Small 2.70-3.00 0.50-1.50 12-17 24-28 Big 2.95-3.20 0.50-1.50 0-3 28-32 Dry Small Small 2.30-2.60 0.50-1.50 30-35 18-22 Big 0.95-1.20 0.50-1.50 45-50 18-22 Big Small 2.85-3.15 0.50-1.50 20-25 28-32 Big 2.90-3.20 0.50-1.50 16-21 36-40 Drier Small Small 3.20-3.50 0.50-1.50 20-26 18-22 Big 0.95-1.20 0.50-1.50 50-56 18-22 Big Small 2.85-3.15 0.50-1.50 26-32 18-22 Big Big 3.55-3.85 0.50-1.50 20-25 15-19 Electrical Wet Small Small 2.60-2.90 0.50-1.50 0-3 3-7 or gas Big 2.60-2.90 0.50-1.50 0-3 3-7 Delicates Big Small 0.95-1.20 1.00-2.00 0-5 6-10 DOD Big 2.35-2.60 0.50-1.50 0-3 3-7 Less Dry Small Small 2.40-2.70 0.50-1.50 0-3 13-17 Big 2.95-3.20 0.50-1.50 0-3 3-7 Big Small 2.05-2.30 0.50-1.50 0-3 11-15 Big 2.85-3.15 0.50-1.50 0-3 7-11 Dry Small Small 2.60-2.90 0.50-1.50 3-7 15-19 Big 3.55-3.80 0.50-1.50 0-5 24-28 Big Small 3.55-3.80 0.50-1.50 0-3 9-13 Big 3.40-3.70 0.50-1.50 0-5 12-16 Drier Small Small 3.55-3.85 0.50-1.50 3-7 8-12 Big 3.55-3.85 0.50-1.50 5-10 10-14 Big Small 3.40-3.70 0.50-1.50 0-5 13-17 Big 3.40-3.70 0.50-1.50 0-5 9-13 Electrical Wet Small Small 3.05-3.30 0.50-1.50 0-3 11-15 or gas Big 2.30-2.60 0.50-1.50 0-3 22-26 Quick Dry Big Small 3.10-3.35 0.50-1.50 0-3 11-15 DOD Big 2.15-2.45 0.50-1.50 0-3 14-18 Less Dry Small Small 3.25-3.55 0.50-1.50 0-5 19-23 Big 3.05-3.30 0.50-1.50 0-3 28-32 Big Small 3.25-3.55 0.50-1.50 3-7 17-21 Big 3.05-3.30 0.50-1.50 0-3 26-30 Dry Small Small 3.25-3.55 0.50-1.50 15-21 22-26 Big 3.45-3.70 0.50-1.50 11-17 14-18 Big Small 3.20-3.50 0.50-1.50 15-21 12-16 Big 3.10-3.35 0.50-1.50 11-17 22-26 Drier Small Small 3.25-3.55 0.50-1.50 25-31 12-16 Big 3.35-3.65 0.50-1.50 20-25 16-20 Big Small 3.40-3.70 0.50-1.50 22-27 24-28 Big 3.20-3.50 0.50-1.50 19-24 20-24

The values on Table (1) are approximate and not restricted to be the predetermined values; similarly, value ranges are used because these vary according to the characteristics of each type of drying machine. Only certain types of cycle are exemplified, nevertheless, it must be noted that this table is applied for any type of cycles and for electrical and gas dryers. Ranges are provided for target voltages and minimum times, nevertheless, target voltage and a minimum time are established for each expression found on the table.

Once the targets voltage value is established, in 160 it is compared against the filtered voltage, and in case that said filtered voltage is greater than (Vfiltered>Vtarget), in 170 a time for achieving the target voltage is set.

Additionally, the “M”, “A”, “multiplier” and “aggregate” values are obtained from the same row in the table and as a function of the same data, respectively, which are values previously calculated by the inventors and by the holder of the present invention, which are used for the subsequent “additional time” calculation, as explained below.

Therefore, only as an example and in order to explain in more detail the use of the aforementioned table, it can be observed that: assuming that a drying cycle is carried out according to the embodiments disclosed herein in an electric dryer, where the selected cycle type is a “Mixed Load” cycle, it is also selected that the required drying level is “less dry”, it is also determined that the restriction is “small” and the load is “small”; therefore, according to Table (1) aforementioned and as function of said previously determined data, it is established that the “target voltage” has a value between 3.50 and 3.8 volts, and that the “Minimum Time” has a value between 13 to 17 minutes of operation time.

Thus, continuing with the drying method and once the “target voltage”, “minimum time”, “multiplier” and “aggregate” values are established, in 180 it is determined if said “minimum time” has elapsed, and once elapsed, in 190 the “additional time” is calculated according to the following equation (1):

T_additional=max{(Heat Factor)×[Trtv(Multiplier−1)+Aggregate];T_minimum−Trtv}

The heat factor can be obtained from the following Table (2):

TABLE (2) Eco Dry Extra-Low Low Medium High Sanitize Electrical 1.58-1.63 2.47-2.52 1.23-1.28 1.23-1.28 0.82-0.87 0.82-0.87 Cotton Electrical 1.58-1.63 2.47-2.52 1.22-1.27 1.22-1.27 0.75-0.80 0.75-0.80 Mixed Load Electrical 1.75-1.80 2.47-2.52 1.23-1.28 0.97-1.02 0.97-1.02 0.97-1.02 Easy Care Electrical 1.39-1.44 2.47-2.52 1.38-1.43 1.15-1.20 1.15-1.20 1.15-1.20 Active Dry Electrical 2.47-2.52 2.07-2.12 0.94-0.99 0.94-0.99 0.94-0.99 0.94-0.99 Delicates Electrical 1.31-1.36 2.47-2.52 0.84-0.89 0.84-0.89 0.35-0.40 0.35-0.40 Quick Dry Gas 1.58-1.63 2.47-2.52 1.23-1.28 1.23-1.28 0.82-0.87 0.82-0.87 Cotton Gas 1.58-1.63 2.47-2.52 1.22-1.27 1.22-1.27 0.75-0.80 0.75-0.80 Mixed Load Gas 1.75-1.80 2.47-2.52 1.23-1.28 0.97-1.02 0.97-1.02 0.97-1.02 Easy Care Gas 1.39-1.44 2.47-2.52 1.38-1.43 1.15-1.20 1.15-1.20 1.15-1.20 Active Dry Gas 2.47-2.52 2.07-2.12 0.94-0.95 0.94-0.99 0.94-0.99 0.94-0.99 Delicates Gas 1.31-1.36 2.47-2.52 0.84-0.89 0.84-0.89 0.35-0.40 0.35-0.40 Quick Dry

The values on Table (2) are approximate and not restricted to be the predetermined values; similarly, value ranges are used because these vary according to the characteristics of each type of drying machine. Only certain types of cycle are exemplified, nevertheless, it must be noted that this table is applied for any type of cycles and for electrical and gas dryers. The values on table 2 are values previously calculated by the inventors and by the holder of the present invention.

Therefore, only as an example and in order to explain in more detail the use of the aforementioned calculation of “additional time”, it can be observed that assuming that a drying cycle is carried out in an electric dryer, where the selected cycle type is a “Mixed Load” cycle, it is also selected that the required drying level is “less dry” (equivalent to “low”), it is also determined that the restriction is “small” and the load is “small”; therefore, according to Tables (1) and (2) aforementioned and as function of said previously determined data, the “additional time” is calculated according to the previous equation (1) and by means of the following operation:

T_additional=max{(1.25)×[≈34(1.05−1)+2];T_minimum−Trtv}

Consequently:

T_additionalmax{(1.25)×[≈1.7+2];T_minimum−Trtv}

and then:

T_additional=max{(2.125);T_minimum−Trtv}

Subsequently, in said method, in 200 the minimum time is compared against Trtv. If T_additional≦0 or T_minimum≧T_additional, then the greater one is used in the calculation.

Subsequently, in 210 it is determined if the elapsed time is less than the total target drying time. If the elapsed time is less than the total target drying time, and achieved target voltage value is returned and in 220 the additional time is added according to the equation (2):

T_Target=T_Additional; |T_Elapsed

If the elapsed time is not less than the target time, a value is returned indicating that the target drying has been accomplished.

If, based on the target voltage and filtered voltage comparison, it is established that the filtered voltage is less than the target voltage, it is determined if the maximum time has elapsed. If the maximum time has elapsed, a value is returned indicating that the target drying has been accomplished. If the maximum time has not elapsed, a null value is returned at the cycle start.

Calculations are performed by the processor 90. The calculations results can be stored in ROM 70.

For a determined cycle, without the modification proposed by the method, using energy cycles, a power consumption of approximately 1910 kwH (power consumption without using the invention) is obtained, nevertheless, using the same configuration and taking into account the modification of an embodiment disclosed herein, power consumption is reduced to 1842 kwH (power consumption using the invention). Therefore, the time and power consumption can be reduced, approximately, from 50 minutes to less than 35 minutes, 33.3 minutes (percentage at which the time or power consumption are reduced).

The following table shows the behavior of this saving cycle against conventional cycles

In regard to drying cycles with energy-saving, such as the one of the embodiments disclosed herein, independently of the heat level, a temperature range must be determined, which is limited in its lower part by the restart or re-ignition temperature of the heaters Tr and in its higher part by the cutoff or shutdown temperature of the heaters Mut, in order to maintain the temperature within the drum at a level that does not damage the load.

As aforementioned, there are three stages in the cycle, a heating, an evaporation, and an overheating. It has been demonstrated that, in order for having an energy-saving, the overheating must be avoided, as it does not contribute to the drying process. In the evaporation, it has been outstandingly demonstrated that it is not necessary to maintain the heaters turned on during the whole cycle, as the potential energy of the heater helps maintaining the evaporation for a determined time. And this manner, the following drying cycle has been designed, which allows to achieve considerable energy savings, as compared to the state-of-the-art.

As it is shown in FIG. 6, once the minimum time has elapsed, the heaters arranged in the dryer must be turned off and subsequently it must be evaluated if the current temperature in relation to the restart temperature, with two possible results:

First, in case that the current temperature is greater than the restart temperature Tr, the heaters will remain turned off onto the additional time determined for the load has elapsed.

Second, in case the current temperature is not greater than the restart temperature, the heaters must be turned on, it being possible to activate only one, or in its case as many as needed for using the required percentage in order to reach an optimal temperature or the cutoff temperature Tcut which will be evaluated by the processor taking into account parameters as heat level, current temperature, load size, etc.

Once the additional time has elapsed, it will be evaluated if the target voltage has been reached.

However, in case of not reaching the target voltage the current temperature must be evaluated in relation to the restart temperature or the cutoff temperature, depending on the heaters being turned off or turned on.

In case that the heaters are turned off, the current temperature must be evaluated against the restart temperature, estimating in first place if the current temperature is less than the restart temperature. In case that it is lower, the heaters must be turned on, it being possible to activate one or more, depending on the total dryer power percentage needed in order to reach the optimal temperature level, in case that the current temperature is not less than the restart temperature, it must be evaluated if the current temperature is greater than the restart temperature, in which case the heaters will remain turned off.

In case that one or more heaters are turned on, the current temperature must be evaluated against the cutoff temperature. In case that the current temperature is greater than the cutoff temperature, all of the heaters must be turned off. In case that the current temperature is not greater than the cutoff temperature, the heaters must remain turned on in the percentage previously determined by the processor.

In case that the target voltage has been reached, a cycle time will be determined for evaluation, in which it will be evaluated if the desired humidity level has been reached, which will be approximately 2%. In the case that said humidity percentage is reached, the heaters must remain turned off and the previously determined cooling phase will start, thus finishing the drying cycle.

The current temperature evaluation compared to the restart temperature and the cutoff temperature can be carried out repeatedly and in the same cycle, and it is detailed graphically in FIG. 6.

The described cycle can be clearly appreciated in FIG. 7, in which surprisingly the following levels of energy savings have been reached.

STATE OF ECO EMBODIMENTS PARAMETER THE ART Cycle DISCLOSED FMC (%) 3.94 3.9 3.9 Total drying time (min) 42.9 50 33.3 Power (kWh) 1.918 1.910 1.842 Power off mode (W) 2.746 1.33 1.33 Standby mode (W) 8.672 2.34 2.34 CEF 3.891 4.11 4.26

Alterations of the structure described herein, can be foreseen by those skilled in the art. Nevertheless, it must be understood that the embodiments are related to the preferred embodiments of the invention, which is for illustrative purposes only, and must not be construed as a limitation of the invention. All modifications which do not depart from the spirit of the invention are included in the body of the attached claims.

Claims

1. A drying procedure comprising the stages of:

determining the type of drying, the drying level, which can vary between high, medium, low or very low; determining the values for load size, humidity level, resistance of the garments to friction and heat and, based on these, setting the values for “target voltage”, “minimum drying time”, “target drying time”, “multiplier” and “aggregate”; verifying if the filtered voltage is greater than the target voltage, in this case sparked the drying cycle turning down the heaters until the heat range previously established in the drying level is reached during, at least, the minimum previously established time; After the minimum time has elapsed, the additional time is calculated by means of a previously established function which is determined based on the heat level determined; Comparing the additional time against the time to reach the target voltage (Trtv), and using the highest time of those; turning off the heaters and starting the cooling period; determining if the elapsed time is greater than the total target drying time; in case that the elapsed time is greater than the drying time, finish the drying cycle; in case that the elapsed time is less, adding a second determined additional time by means of a previously established function, different from the function for determining the first additional time; when the total target drying time is reached, finish the drying cycle; which is characterized by including “restart temperature” and “cutoff temperature” values that determined based on the given temperature level and by including additional steps in order to achieve energy savings before the “turn off the heaters and start the cooling period” stage;

the steps for achieving the energy savings are:

evaluating the current temperature and based on it determining if the heaters must remain turned off or the percentage of them which must be turned on; evaluating if the target voltage has been reached; when the target voltage is reached, continue with the corresponding stage of the drying cycle.

2. The drying procedure of claim 1, wherein while evaluating the current voltage, it has not reached the target voltage, which comprises the additional step of evaluating if the current temperature is less than the restart temperature or greater than the cutoff temperature.

3. The drying procedure of claim 2, wherein while evaluating if the current temperature in relation to the restart and cutoff temperatures it is determined if the heaters must remain turned off or turned on.

4. The drying procedure of claim 1, wherein while evaluating that coverage temperature this is less than the restart temperature, and as a consequence at least one of the heaters is turned on in a percentage that could be from 1% to 100% of the total power.

5. A drying procedure in a household appliance which comprises a) a drum for containing the textile garments to be dried, humidity sensor bars, at least one heater and one controller circuit, where the method comprises the stages of:

with the help of the controller circuit, determining the type of drying, the drying level, which can vary between high, medium, low or very low; determining the values for load size, humidity level with the help of the sensor bars, resistance of the garments to friction and heat, and based on these establishing the values for “target voltage”, “minimum drying time”, “target drying time”, “multiplier” and “aggregate”; verifying if the filtered to voltage is greater than the target voltage, in this case start the drying cycle turning on at least one heater until the previously established and needed heat range is reached in the rotating drum at the drying level, during at least, the minimum previously established time; after the minimum time has elapsed, the controlling circuit calculates the additional time by means of a previously established function which is determined based on the level of heat determined; comparing the additional time against the time needed for reaching the target voltage (Trtv), and using the higher time of those; turning off the at least one heater and starting the cooling period; Determining if the elapsed time is less than the total drying target time; in case that the elapsed time is greater than the target drying time, finish the drying cycle; in case that the elapsed time is less, add a second determined additional time by means of a previously established function, different from the function used for data mining the first additional time; when the total target drying time is reached, finish the drying cycle; the drying procedure is characterized by including values for “restart temperature” and “cutoff temperature” determined based on the given temperature level, and by including additional steps in order to achieve energy savings before the “Turn off the heater or heaters and start the cooling period”;

the steps for achieving the energy savings are:

evaluating the current temperature within the rotating drum and based on it determining if the heater or heaters must remain turned off or the percentage of them which must be turned on in order to maintain the rotating drum at an evaporation temperature; evaluating if the target voltage has been reached; when the target voltage is reached, continue with the corresponding stage of the drying cycle.

6. The drying procedure in a household appliance of claim 5, wherein if while evaluating the current voltage, it has not reached the target voltage, which comprises the additional step of evaluating if the current temperature is less than the restart temperature or greater than the cutoff temperature.

7. The drying procedure in a household appliance of claim 6, wherein while evaluating if the current temperature in relation to the restart and cutoff temperatures it is determined if the heaters must remain turned off or turned on.

8. The drying procedure in a household appliance of claim 5, wherein while evaluating that coverage temperature this is less than the restart temperature, and as a consequence at least one of the heaters is turned on in a percentage that could be from 1% to 100% of the total power of the household appliance.

9. A drying apparatus comprising: a) a drum for containing textile garments to be dried, humidity sensor bars, at least one heater and a drying controller circuit, characterized by the drying circuit being configured to determine a temperature and a drying time as a function of the textile garments load to be dried, determining an additional drying time and an energy saving percentage as a function of the evaporation temperature of the rotating drum, where the at least one heater is configured and controlled by the controller circuit in order to provide heating power percentages for a predetermined time for maintaining the temperature of the rotary drum within an evaporation temperature range which allows saving energy during the determined time period.