RU2474633C2 - Drying machine for laundry or washing machine with dryer - Google Patents

Abstract

FIELD: textiles, paper.

SUBSTANCE: laundry is dried in the drum (2) under the influence of air flow evaporating the water contained in the laundry, and the drying cycle includes at least one stage of the closed loop during which the air flow with constant air mass (1, 10) passes several times through the drum (2), and at least one stage of the open loop during which the air flow has the air mass intake from the ambient environment and then discharged into the ambient environment after a single flow through the drum (2), and air is heated in during the stage of the closed loop.

EFFECT: improvement of the method.

20 cl, 14 dwg

Description

The invention relates to a ventilation dryer for clothes or a washing machine with dryer according to the restrictive part of paragraph 1 of the claims.

The so-called "ventilation" machines differ from the "condensation" machines in the principle of operation: in the first type of machines, moist air is discharged into the external environment without condensing inside the machine (unlike the last type of machines). Ventilation machines are simpler because they do not have a condenser and all the parts associated with it (tanks for collecting condensation water, channels, control systems and other components).

Such machines are usually equipped with a drum in which laundry is placed under the action of an air flow generated by the fan, heated by electrical resistance.

GB 595305 describes such a ventilation dryer for laundry with two processing steps: during the first step, the air inside the machine passes in a closed loop, several times passing through a drum with drying laundry and taking a certain amount of moisture from the laundry with each passage. When air reaches a certain degree of humidity, the circuit opens into the external environment during the partial replacement operation stage, in which a portion of moist air is discharged into the environment, while the remaining portion is mixed with fresh air having a low degree of humidity (ambient air).

The partial replacement step, in which moist air is mixed with ambient air, occurs when the heater is on, so that a certain temperature of the air is constantly maintained to improve the removal of moisture from the laundry.

Some of the drawbacks of this solution relate to energy consumption and to determining when to open the circuit to allow ambient air to partially replace the air circulating inside the machine.

The partial replacement step actually continues until the end of the drying cycle (when the laundry becomes dry) with the heater constantly on to prevent a drop in air temperature. On the one hand, this provides a faster drying cycle, and on the other hand, it causes high energy consumption due to the need for continuous operation of the electric heater due to the constant flow of air with a low temperature.

The determination of the moment when the cycle should be switched from the closed loop mode to the partial replacement mode, depending on humidity, turned out to be inaccurate: at the initial stages of the cycle, due to very wet loaded laundry, the hygrometer readings may have significant deviations, therefore, the beginning of the partial replacement cycle can be assigned at inappropriate times (i.e., at low humidity of the circulating air). Of course, it is theoretically possible to use very accurate hygrometers suitable for this purpose, but such devices are so specific and expensive that they cannot reasonably be used in a clothes dryer.

In this regard, an alternative was proposed in GB 2094963, in the description of which a drying cycle is disclosed, including the initial stage of partial replacement and the subsequent open circuit step: the machine starts drying the laundry, partially replacing the volume of air circulating in the machine, so as to reduce its humidity; Following this, it switches to the open loop mode, in which air is taken in from the outside and released into the external environment after only a single flow through the drum. This step occurs with the heater turned off so that the laundry cools before removing it.

Switching between these two operating steps (partial replacement and open circuit) takes place in accordance with a predetermined time interval or depending on the humidity determined by the hygrometer.

However, this solution also has drawbacks related to energy consumption and to determining when the operating mode should be switched: in fact, in this case as well, the heater remains switched on during the supply of fresh air, thus leading to a significant loss of energy, exactly the same as in the previously described case.

In addition, if the switching between these two operating modes is determined in accordance with a predetermined time interval, the latter will not take into account any of the variables related to the machine (humidity of the laundry, humidity, the number of items to be dried, etc. ), and therefore, the switching time cannot be based on optimal conditions for the machine and the loaded laundry. On the other hand, in the case where air humidity is determined to determine the switching time, the above problems arise.

The present invention relates to a clothes dryer or washing machine with dryer according to paragraph 1 of the claims.

The idea underlying the present invention is to provide such a method of ventilating drying of laundry in which each complete drying cycle includes at least one first step of a closed circuit, during which the same volume of air circulates in the drum, and at least at least one second stage of the open circuit, during which the air circulating in the drum is taken from the external environment and discharged into it, while the air is heated during the first stage.

In this description, the term "full drying cycle" means the duty cycle of the machine, which begins by exposing the machine to wet laundry, and ends when the laundry becomes dry.

This method has the advantage that the heater (usually electrical resistance) is turned on only when the machine is in closed loop mode, which significantly reduces energy consumption. In fact, as you can easily understand, the thermal energy transferred to the volume of air (which is always the same) circulating inside a closed circuit in a machine is less than the thermal energy that would be transferred if heating were required (as in the well-known prior art) during a partial replacement step or open loop.

The features of a clothes dryer or washer / dryer according to the invention are set forth in the appended claims.

These features, as well as additional advantages of the present invention, will become apparent from the following description of a variant of its implementation, which is shown in the accompanying drawings.

Figure 1 shows a clothes dryer or washing machine with dryer according to the present invention, a sectional view;

figure 2 - the first stage is the stage of circulation in a closed cycle in the machine shown in figure 1;

figure 3 - the second stage is the open circuit stage in the machine shown in figure 1;

figure 4 is a fragment of the flow diverter in the state depicted in figure 2;

figure 5 is a fragment of the flow diverter in the state depicted in figure 3;

Fig.6 is a fragment of the flow deflector in a state of partial replacement;

7 shows an alternative embodiment of the air intake duct;

on Fig shows an alternative embodiment of the machine shown in figure 1, in which the flow diverter is replaced by two dampers;

figure 9 schematically shows a drying cycle according to the present invention;

figure 10 shows the drying cycle, an alternative to the drying cycle shown in figure 9;

11 shows an additional embodiment of the drying cycle shown in FIG. 9, including any number of repetitions of the open loop step and the closed loop step;

12 shows a further alternative embodiment of a flow diverter;

in Fig.13 shows the flow diverter depicted in Fig.12, in a closed loop state;

on Fig shows the flow diverter shown in Fig, in the state of the open circuit.

A ventilation dryer or washing machine 1 with dryer is shown in figure 1 in a simplified form to facilitate understanding of its operation

The machine 1 has a rotating drum 2, in which the user places the laundry 3, which is dried by the air flow created by the fan 4, heated by an electrical resistance 5.

A hot air stream washes the laundry 3 (thereby removing moisture from the laundry) and then enters the channel 6, which is in fluid communication with the drum 2.

Behind the channel 6 in the flow direction, as will be described in more detail below, there is a flow diverter 7 that connects four channels: a return channel 6 for drawing air from the drum, an exhaust channel 8 for discharging air into the external environment, and a suction channel 9 for drawing air from environment and the supply channel 11, leading to the fan 4 and containing resistance 5. As will be described later, when exposed to the diverter 7 flow will be obtained either a closed loop mode or open loop mode.

First of all, it is necessary to consider the position of the flow deflector with respect to the four channels 6, 8, 9, 11: as shown in more detail in Figs. 4-6, it is located in the chamber 70 in which these four channels converge. More specifically, the channels connected to the chamber 70 are a return channel 6 located on one side of the flow deflector 7 for drawing air from the drum and a supply channel 11, and an outlet channel 8 for discharging air into the external environment and an intake suction channel 9 located on the opposite side of the deflector air from the environment. The flow diverter can rotate around its axis in such a way as to result in fluid communication of the return channel 6 with the supply channel 11 and the suction channel 9 with the exhaust channel 8, as shown in FIG. 4, or the return channel 6 with the exhaust channel 8 and suction channel 9 with the feed channel 11, as shown in Fig.5.

It should be noted that the chamber 70 and channels are shaped so as to minimize pressure loss with significant structural simplicity.

As will be better explained below, the flow diverter 7 can also occupy intermediate positions between the two positions described above to partially replace the flows discharged into the external environment, the flows sucked from the external environment, and the flows circulating between channel 6 and channel 11.

First, these two work steps will be briefly described, the alternation of which will be discussed in detail later.

During the first working stage of the machine, referred to as the closed loop step (or recirculation step), the diverter 7 is in the state shown in FIG. 4. This leads to the fact that the same volume of air circulates inside the machine, following the route indicated by the arrows in figure 2: air heated by resistance 5 is pumped by fan 4 into drum 2 and washes the laundry, removing moisture from it. Then, air enters the return channel 6, from which it enters the chamber 70, where it is directed by the diverter 7 into the supply channel 11 and returns to the resistance 5, thus performing recirculation.

In this case, during the closed loop mode, the resistance 5 is turned on and quickly heats the circulating volume of air, which, in turn, increases the temperature of the laundry 3 and extracts moisture from it.

During the second working stage, called the open loop stage, the deflector is rotated around its axis, as shown in Fig. 5, so that the air passes along the route indicated by the arrows in Fig. 3: air is sucked in from the outside through the suction channel 9, which is in communication with the feed channel 11, and is pumped by the fan 4 into the drum 2. Then the air washes the laundry, removing moisture from it, and enters the return channel 6, which is in communication with the exhaust channel 8, through which air is discharged into the external environment.

In this case, the route followed by the hot air stream is an open circuit in which air is drawn in from the external medium, supplied to the drum 2, and then discharged into the external environment again. It is important to note that during this second operating stage, the electrical resistance 5 is turned off, which will be discussed in more detail below.

It should also be noted that the machine 1 may include a temperature sensor 13 and a humidity sensor 14, the use of which will be described later.

Now we can consider the way the above machine operates.

According to the process schematically illustrated in Fig. 9, after the laundry 3 has been placed in the drum 2, the machine 1 first operates in a closed loop mode, so that the volume of air circulating inside the machine heats up very quickly, thereby heating the laundry and removing it moisture.

Upon reaching a certain threshold of the air temperature, which is determined by the temperature sensor 13, the flow diverter 7 is controlled in such a way as to start the second working stage.

It should be noted that switching between open-loop and closed-loop modes based on air temperature overcomes the drawback of the prior art: in fact, during this first working step, a serial hygrometer 14 would give inaccurate readings due to the high degree of humidity of both the circulating air and the loaded laundry .

On the contrary, this determination of the moment of switching from a closed circuit to an open circuit (and turning off the resistance) will be much more accurate depending on the temperature, because the thermometer 13 is not affected by humidity, and therefore provides a very accurate indication.

The tests showed that the threshold temperature, which can be considered optimal (in terms of energy consumption and the amount of water extracted from the laundry), is in the range from 60 ° C to 80 ° C, preferably 70 ° C.

When the second stage of the open circuit begins, the laundry will already lose a certain amount of water and reach a certain temperature, higher than room temperature (and essentially equal to the threshold temperature). During this working step, the electrical resistance can be turned off, while the air washing the laundry has room temperature, however, it can extract moisture from the laundry until the latter becomes completely dry (that is, it does not have a natural degree of humidity), ending thereby the drying cycle without the need to re-enable the electrical resistance, but simply by using the temperature reached by the linen during the first stage and air circulation at room temperature, which ensures Significant energy savings.

Of course, if the main thing is to be the drying time, then it will be possible to leave the resistance turned on even during the open circuit stage, although this will imply a certain energy loss, actually reducing the advantages in energy consumption.

Thus, the advantages of the present invention are obvious: during the first stage, the mass of air heated by the resistance continues to circulate inside the closed circuit of the machine until the air reaches the required temperature; when the laundry is sufficiently heated (that is, when the threshold temperature is reached), the resistance turns off and the cycle continues using unheated ambient air, thereby reducing energy consumption. The temperature actually reached by the laundry is sufficient so that the surrounding air circulating around the laundry removes any residual moisture, thereby completing the drying cycle.

The main process described above can be subjected to numerous changes without departing from the scope of the present invention.

According to a first embodiment of the invention, the circulating air stream is mixed with the fresh air stream, so that a portion of the hot and moist air stream coming from the channel 6 is discharged into the external environment. This working step, which can be called the “partial replacement step”, corresponds to the state of the flow deflector shown in FIG. 6, in which it is rotated so that the flow flowing through channel 6 is divided into two parts, one of which is discharged through the exhaust channel 8 , and the other, i.e. The "recirculating" part again enters the supply channel 11. Of course, it is understood that air is supplied through the suction channel 9 in an amount equal to the amount of exhausted air, and this incoming air is mixed with the recirculating air stream.

Such a working stage with partial replacement allows (especially when the volume of air during exchange with the external environment is kept small relative to the volume of air circulating in the machine) to prevent excessive cooling of the laundry and the air circulating in the machine, while at the same time reducing their humidity and thereby providing additional extraction of water from the laundry.

Unlike the known solutions, according to the present invention, during the partial replacement step, the electrical resistance can be turned off, which is useful from the point of view of energy consumption.

Another embodiment of the method, which is particularly advantageous in terms of energy consumption, is shown schematically in FIG. 10. This method includes four stages: the first stage with a closed circuit and resistance turned on, the second stage with an open circuit and resistance turned off, the third stage again with a closed circuit and resistance turned on, and the fourth cooling stage with an open circuit and resistance turned off.

When analyzing in more detail the transitional moments between these four stages, it should be noted that they are determined based on the readings of temperature or humidity. More specifically, the moment of transition between the first and second stages is set depending on the threshold temperature, in the same way as described above, and for the same reasons that make it unnecessary to use humidity readings as a reference point.

On the contrary, the moment of transition between the second and third stages is set depending on a certain degree of air humidity, which in the example described here is a threshold value between 90% and 95% of the air humidity in the channel. In this case, a more accurate measurement of the drying state of the laundry is provided by a hygrometer, which in this operating mode of the machine has very good sensitivity characteristics.

The transition between the third and fourth stages is set again depending on the temperature threshold, exactly the same as the first transition, but for other reasons: in this case, the laundry actually has a lower degree of humidity and, therefore, tends to dry and dry during the drying process overheat very quickly, at the risk of damage. For this reason, it is preferable to use a temperature threshold value between 60 ° C and 80 ° C (preferably 70 ° C) at which the resistance is turned off and the circuit opens so that the last small fraction of moisture can be released into the external environment and the laundry can cool before its extraction by the user.

11 schematically shows an alternative solution, which is especially effective when the laundry is heavily soaked with water (for example, due to its thickness or type of fabric). The closed loop and open loop steps are repeated several times until the laundry is dry (three dots in this figure mean that there can be any number of repetitions).

The number of repetitions can be selected depending on the duration of the closed loop stage at each repetition. The duration of the closed loop stage actually becomes shorter as the amount of water in the laundry decreases, since the less water in the linen, the faster the air reaches the threshold temperature, therefore, you can set the minimum threshold duration of the closed loop stage (for example, approximately 30 seconds) at the end of which it is assumed that the laundry is dry.

In this regard, it can be noted that the duration of the closed loop stage is used as a parameter on the basis of which the degree of drying of the laundry is measured. The machine described above, of course, can also be subjected to many changes. In particular, although the suction channel 9 and the exhaust channel 8 in the drawings are shown adjacent to each other, they can open into the environment at a distance from each other, as shown by way of example in FIG. 7, so that more fresh air can be sucked in.

Similarly, a person skilled in the art can, of course, choose other designs for the flow diverter 7 and the chamber 70 so that they provide for the implementation of the above-described work steps.

For example, in a dryer or washing machine 10 with a dryer according to an alternative solution shown in FIG. 8, the suction channel 9 and the exhaust channel 8, instead of converging to the flow diverter 7 and the chamber 70, converge directly to the fan, and each of them equipped with shutters 7A, 7B. Thus, the first working step is performed when the shutters 7A and 7B close, respectively, the suction channel 9 and the exhaust channel 8, and the second working step is carried out when the shutter 7A opens the exhaust channel 8 and closes the supply channel 11, while the shutter 7B opens the suction channel 9.

In this case, it is also possible to obtain the above partial replacement step by properly adjusting the shutters 7A, 7B.

Another extremely simple structurally and, therefore, advantageous embodiment of the flow diverter is shown in FIG. The same flow diverter is shown in figures 13 and 14 in the positions corresponding to the states of the closed loop and open loop.

In this case, the suction channel 90 and the exhaust channel 80 simply open on the rear wall 81 of the machine through a single opening 100. In the closed loop position, the flow diverter 70 simply connects the return channel 6 to the supply channel 11, thereby closing the opening 100.

In the open loop state shown in FIG. 14, the flow deflector 70 is rotated about its middle axis, forming one of the walls of the suction channel 90 and the exhaust channel 80. In particular, it forms a common wall between the two channels, dividing the single opening 100 into two channel 80 and 90.

This solution provides a very simple implementation of the invention.

Alternatively, the electrical resistance may be replaced by a gas heater or the like.

Of course, the machine according to the present invention is equipped with a control unit that receives signals from the sensor 13 (temperature or humidity) and controls the flow diverter or dampers in such a way as to select the most suitable processing step. For this purpose, the flow diverter or dampers are driven by a specialized electric motor controlled by the control unit.

Also, the machine, in addition to the parts described above in order to illustrate the invention, contains all those parts that are usually found in machines of this kind: an electric motor for rotating the drum, a user interface, and in the case of a washing machine with dryer, also all those parts that are usually required to carry out the function of washing clothes.

Claims (20)

1. The method of drying clothes (3) in a ventilation dryer or washing machine with dryer (1, 10), in which the laundry is placed in a drum (2) for drying, where it is exposed to air flow, which leads to evaporation of the water contained in the laundry characterized in that the drying cycle includes at least one stage of a closed circuit, in which an air stream with a constant mass of air passes several times through the drum (2), and at least one stage of an open circuit, in which the air stream contains a lot of air th from the external environment and discharged into the environment after the single flow through the drum (2), wherein heated air within the closed loop phase. 2. The method according to claim 1, characterized in that during the open circuit stage the air is not heated. 3. The method according to any one of claims 1 or 2, characterized in that the switching between the closed loop step and the open loop step is determined depending on the air temperature. 4. The method according to claim 3, characterized in that the threshold temperature value, which determines the switching between the closed loop step and the open loop step, is in the range from 60 ° C to 80 ° C, preferably 70 ° C. 5. The method according to claim 1, characterized in that it includes four sequentially performed steps:
- the first stage with a closed circuit and heating the air;
- the second stage with an open circuit without heating the air;
- the third stage with a closed circuit and heating the air;
- the fourth stage with an open circuit without heating by air. 6. The method according to claim 5, characterized in that the switch between the first and second stages is set depending on the first air temperature threshold, the switch between the second and third stages is set depending on the air humidity threshold, and the switch between the third and fourth stages is set to depending on the second air temperature threshold. 7. The method according to claim 6, characterized in that the first temperature threshold value is essentially 70 ° C, the humidity threshold value of the air flowing out of the drum is in the range from 90% to 95%, and the second temperature threshold value is essentially equal to 70 ° C. 8. The method according to claim 1, characterized in that it includes sequential repetition of the preferred number of times:
- the first stage with a closed circuit and heating the air;
- the second stage with an open circuit. 9. The method according to claim 8, characterized in that the open circuit step occurs without heating the air. 10. The method according to any one of paragraphs.8 or 9, characterized in that the number of repetitions of the first and second stages is set depending on the duration of the closed loop stage. 11. The method according to any one of claims 8 to 10, characterized in that the switching between the first and second stages is set depending on the first air temperature threshold, and the switching between the second stage and the next stage is set depending on the air humidity threshold. 12. The method according to claim 11, characterized in that the temperature threshold value is in the range from 60 ° C to 80 ° C, preferably 70 ° C, and the humidity threshold value of the air flowing out of the drum is in the range from 90% to 95%. 13. The method according to any one of claims 1 to 12, characterized in that it further includes a partial replacement step, in which part of the air mass circulating in the machine (1, 10) is replaced with an equal amount of ambient air, while the air is not heated. 14. A dryer or washing machine with dryer (1, 10), comprising a drum (2) for the clothes to be dried (3), a heater (5) for heating the air flow generated by the fan (4) flowing through the drum (2) to flush the contained in it, for the purpose of extracting moisture from it, return (6) and supply (11, 11A, 11B) channels for the exit of air flow from the drum (2) and supply to it, respectively, as well as an exhaust channel (8, 80) for the release of air into the external environment and the suction channel (9, 90) for the suction of ambient air, characterized in that has a flow diverter (7, 7A, 7B, 70) configured to alternately communicate through the fluid a return channel (6) with a supply channel (11) and a suction channel (9, 90) with an outlet channel (8, 80), or a return channel (6) with an outlet channel (8, 80) and a suction channel (9, 90) with a supply channel (11), opening or closing the circuit with the subsequent flow of air through the drum (2). 15. Machine (1, 10) according to 14, characterized in that the flow deflector (7) is located in the chamber (70), the air return channel (6) and the supply channel (11) converge to the said chamber on one side of the deflector ( 7), and the air outlet channel (8) and the suction channel (9) converge to the chamber (70) on the opposite side of the deflector (7), and the flow deflector (7) can be rotated around its axis to open or close the circuit with subsequent flow air through the drum (2). 16. The machine (1, 10) according to 14, characterized in that the suction and exhaust channels (90, 80) have the ability to open in a single hole (100) in the rear wall of the machine, and in a closed circuit, the flow diverter (70) has the ability to connect the return channel (6) with the supply channel (11), while closing the hole (100), and in the open state, the flow diverter (70) is rotated around its middle axis and divides the hole (100) into the exhaust and suction channels ( 80, 90), forming a common wall between them. 17. Machine (1, 10) according to any one of claims 14-16, characterized in that when the circuit along which the air flowing through the drum (2) is closed, the heater (5) is turned on, and when the circuit, according to which follows the air flowing through the drum (2), is open, the heater (5) is turned off. 18. Machine (1, 10) according to any one of paragraphs.14-17, characterized in that the flow diverter (7, 70) has the ability to be installed in intermediate positions to partially replace the air stream exiting through the return channel (6) and transmitted into the exhaust channel (8, 80), equivalent flows of ambient air, sucked through the suction channel (9, 90) and transmitted to the supply channel (11). 19. Machine (1, 10) according to one or more of claims 14-18, characterized in that it comprises a temperature sensor (13) and a humidity sensor (14) for detecting the temperature or humidity of the air flow circulating inside the drum. 20. Machine (1, 10) according to one or more of claims 14-18, characterized in that it is configured to implement the method according to one or more of claims 1 to 13.

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