Household appliance for generating steam

Abstract

The utility model relates to a household appliance for generating steam, which comprises a water tank under atmospheric pressure; a boiler adapted to contain water to be evaporated to a predetermined water level wherein an interior portion of the boiler is divided into a first lower portion, typically occupied by water, and a second upper portion, above the first lower portion, typically occupied by steam; a water level sensor disposed such that at least a portion thereof is located within the second upper portion of the boiler; control means adapted to maintain the water level in the boiler within a predetermined water level range, and adapted to cooperate with said water level sensor, and to operate the means to supply water to deliver an amount of water to the boiler when said water level sensor detects a temperature above a preset threshold. A water level sensor is disposed such that at least a portion thereof is located within the second upper portion of the boiler. In addition, the household appliance further comprises a plate fixed on the bottom surface of the boiler lower cover. Therefore, the water level sensor is not easily covered by incrustation existing in water, so that the service life of the water level sensor is longer.

Description

Technical Field

[0001] The utility model relates to a household appliance for generating steam in a boiler, and in particular to a household appliance equipped with a water level sensor, wherein the water level sensor is placed in a position inside the boiler to ensure that the water level sensor does not come into contact with water. Background Art

[0002] Nowadays, household appliances such as irons and steam cleaners use steam generated in boilers. Usually, water in the boiler is heated to form steam, and the user uses the steam released from the boiler. By using the steam, the water level in the boiler drops, so it is necessary to add water to the boiler again when releasing the steam.

[0003] The water replenishment process in the boiler is managed by sensors that control the pumps through electronic or motor elements to supply the boiler with the right amount of water to restore the water level inside the boiler, as the boiler consumes water.

[0004] Frequent water replenishment is usually required to prevent a large amount of cold water from entering the boiler, thereby preventing the temperature inside the boiler from dropping too low, so as not to affect the performance required by the household appliance. In fact, boilers usually operate between 120℃ and 170℃, depending on the type of household appliance used, so the temperature should not drop suddenly, so as not to cause a significant drop in pressure.

[0005] There are many patents on this subject.

[0006] For example, European patent EP 843.039 B1 in the name of SEB SA describes an iron in which the temperature sensor is located outside the boiler. However, this solution has performance limitations because the sensor cannot immediately sense contact with water and therefore has key problems in effectively detecting water temperature.

[0007] Furthermore, European patent EP 877.200B1, which is the same applicant as the present invention, describes a household appliance for steam generation, wherein the boiler comprises a resistor and a temperature sensor, arranged inside an external support structure. The bent portion of the resistor is higher than the rest, and the external support structure of the temperature sensor is welded on the bent portion rising from its transverse direction. In this way, once this area appears due to a drop in the water level in the boiler, the temperature rises significantly, which is detected by the temperature sensor, which activates the micro pump to introduce a sufficient amount of water into the boiler to raise the water level in the boiler again. The advantage of this device is that when the water level drops, only the high part of the resistor is exposed to the water surface, allowing the remaining part of the resistor to be always immersed in the water, thus avoiding a temperature rise that could endanger its life. However, the inventors of the present invention have found that the device requires heavy assembly work to avoid the wrong position of the support structure on the raised portion, which may lead to an incorrect position of the sensor relative to the heating source.

[0008] European patent EP 1.269.072 B1, also filed by the same applicant as the present utility model, describes a household appliance in which a sensor is placed inside the boiler, in an area frequently reached by the water level during the charging phase of the micropump. As a result, the sensor tends to become dirty and scaled over time, especially in the presence of particularly hard water. As a result, the thermal readings become less sensitive over time, and the sensor is therefore almost unusable.

[0009] U.S. Patent US 5881207 A describes an automatically powered steam generator having a liquid level sensor disposed in an area of ​​a container and located at a set threshold water level, the sensor measuring temperature and comparing it with a reference temperature to determine whether the liquid has reached the threshold water level, and a regulating device interacting with the steam extraction operation so that the sensor temperature varies with the liquid level within a range of variation, wherein the reference temperature is maintained within the range of variation.

[0010] Therefore, the applicant of the present utility model application has found it necessary to create a household appliance for generating steam in a boiler, wherein the sensor designed for detecting the water temperature in the boiler has the characteristics of long-lasting durability and resistance to scaling. Summary of the invention

[0011] In a first aspect, the invention relates to a household appliance for generating steam.

[0012] The applicant of the present application has surprisingly found that the above-described technical problem can be effectively and reliably solved by using a household appliance for generating steam, the household appliance comprising:

[0013] - a water tank at atmospheric pressure;

[0014] - a boiler adapted to contain water to be evaporated up to a predetermined level, wherein the internal portion of said boiler is divided into a first lower portion, which is normally occupied by water, and a second upper portion, which is above said first lower portion, which is normally occupied by steam;

[0015] - means for conveying water from said tank to said boiler,

[0016] - a heating source to evaporate the water,

[0017] - a water level sensor;

[0018] - a control device adapted to maintain the water level in the boiler within a predetermined water level range, wherein the control device is adapted to cooperate with the water level sensor and to operate the device to supply water when the water level sensor detects a temperature above a predetermined threshold value, so as to provide a certain amount of water to the boiler.

[0019] Furthermore, the water level sensor is arranged such that at least a portion thereof is located within the second upper portion of the boiler.

[0020] In this way, the water level sensor is placed in a space inside the boiler where only steam usually exists; this prevents the water level sensor from coming into contact with the water inside the boiler, which is usually rich in mineral salts (unlike steam, which is shaped like distilled water).

[0021] Therefore, the water level sensor is less likely to be covered by scale present in the water, which makes its life longer.

[0022] During steam discharge or boiler heating, the water level sensor detects the temperature inside the boiler; based on the detected temperature change compared to the previous measurement, the water level in the boiler is estimated and new water is therefore filled into the boiler from the tank if necessary.

[0023] This preset water level is a value contained within a range that is automatically adjusted based on the amount of steam used.

[0024] According to a preferred embodiment, the boiler consists of a lower cover and an upper cover, connected to each other to form the first lower part and the second upper part of the boiler therein.

[0025] According to a preferred embodiment, the boiler is made of stainless steel.

[0026] According to a preferred embodiment, the water level sensor consists of a main body having an upper part fixed to the outer surface of the boiler upper cover, a middle part, which passes through the upper cover, and a lower part (including the functional part of the water level sensor for data detection) located in the second upper part of the boiler, where usually only steam exists.

[0027] In this way, the water level sensor is fixed to the outside of the boiler, for example by screws, making it easier to fix and remove, for example when replacement is required. At the same time, the functional part of the water level sensor is placed inside the boiler, in the area occupied by steam.

[0028] According to a preferred embodiment, the water level sensor is a thermal sensor, such as a negative temperature coefficient (NTC).

[0029] According to a preferred embodiment, the household appliance of the present invention further comprises a water inlet for entering the boiler.

[0030] In this way, an additional amount of water can be supplied to the boiler.

[0031] According to a preferred embodiment, the household appliance of the present invention further includes a boiler exhaust device.

[0032] In this way, the contents of the boiler can be drained, for example for preventive maintenance to regularly remove water rich in mineral salts that has accumulated in the boiler and avoid excessive accumulation.

[0033] The household appliance of the present invention further comprises a plate fixed to the bottom surface of the lower boiler cover. Preferably, the plate is made of die-cast aluminum.

[0034] According to a preferred embodiment, said heating source for evaporating water is an electrical resistance.

[0035] According to a preferred embodiment, the resistor is in the shape of a die-cast ring and is fixed on the aluminum plate.

[0036] In this way, the boiler is heated by means of a resistor fixed to a die-cast aluminum plate, which acts as a heater.

[0037] In fact, the plates (and therefore the entire boiler) are kept at the desired temperature, for example 150°C, which is the temperature that produces steam and allows the user to extract it from the boiler. The pressure is calculated according to the temperature so that there is a pressure of about 5 bars in the boiler.

[0038] According to a preferred embodiment, the household appliance of the present invention further comprises a second sensor, which is independent of the water level sensor, to adjust the temperature of the boiler heated by the plate.

[0039] According to a preferred embodiment, the household appliance of the present invention further includes a thermal limiter.

[0040] Preferably, the thermal limiter is fixed on the plate below the lower surface of the boiler.

[0041] According to a preferred embodiment, the household appliance of the utility model further comprises a thermal fuse. Preferably, the thermal fuse is connected in series with the resistor and the thermal limiter, and the resistor and the thermal limiter are both placed on the plate located on the bottom surface of the lower pot cover.

[0042] In this way, when the system overheats beyond a certain temperature, the thermal fuse and thermal limiter connected in series act as electrical safety devices in a coordinated and redundant manner to interrupt the current path.

[0043] According to a preferred embodiment, said means for conveying water from said water tank to said boiler comprise a pump, a first connection between said water tank and said pump, and a second connection between said pump and said boiler.

[0044] In this way, the pump supplies cold water to the boiler, which is then heated by the resistors in the form of die-cast rings on the aluminum plate, which in turn is fixed to the lower boiler part.

[0045] According to a preferred embodiment, said control device for maintaining the water level in the boiler within a predetermined range is represented by an electronic card equipped with a microprocessor suitable for cooperating with said water level sensor.

[0046] In fact, when the water level sensor detects a temperature above a preset threshold, the microprocessor then activates the pump to supply the boiler with a quantity of cold water from the tank.

[0047] According to a preferred embodiment, the household appliance of the present invention further comprises a device for delivering steam from the boiler to a steam user device.

[0048] According to a preferred embodiment, said means for delivering steam comprises a solenoid valve located on the upper surface of the boiler.

[0049] In this way, the solenoid valve allows steam to be discharged from the boiler.

[0050] According to a preferred embodiment, the device for conveying steam further comprises a steam pipeline connecting the solenoid valve and a steam user device.

[0051] According to a preferred embodiment, the device using the steam generated by the household appliance of the utility model is an iron, or an appliance for cleaning objects, and the appliance is selected from the following group, which includes floors, carpets, armchairs, curtains, glass, etc.

[0052] According to a preferred embodiment, the device for utilizing steam generated by a household appliance is equipped with a button to manage the steam supply.

[0053] In this way, by pressing a button, a user can operate the steam distribution device to allow steam to be drawn from the boiler and delivered from the boiler to the steam user device. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Further features and advantages of the present invention will be better highlighted by examining the following detailed description of preferred but non-exclusive embodiments, with the support of the accompanying drawings, which are provided for reference and non-limiting purposes only, in which:

[0055] Figure 1 An axonometric view of a household appliance for generating steam according to the present invention is shown;

[0056] Figure 2 Shown in detail Figure 1 Boiler lower cover of Zhongdian;

[0057] Figure 3 Shows Figure 1 Side view of the boiler of Zhongdian;

[0058] Figure 4 Shows Figure 1 Schematic diagram of the device in the figure, connected with the device used by the user. DETAILED DESCRIPTION

[0059] The following detailed description refers to a specific embodiment of the household appliance of the present utility model, but is not limited to its content.

[0060] In particular, the embodiments described herein refer to Figure 1-4 , relates to a household appliance 1 for generating steam of the utility model.

[0061] The device 1 comprises a water tank 2 at atmospheric pressure, a boiler 3, a pump 4 for pumping water from the water tank 2 into the boiler 3, a first fitting 15 located between the water tank 2 and the pump 4, and a second fitting 16 located between the pump 4 and the boiler 3.

[0062] The boiler 3 is made of stainless steel and consists of a lower cover 3a and an upper cover 3b, which are connected to each other to form a space therein. A first lower portion 7a of the inner space is usually occupied by water, while a second upper portion 7b is usually occupied by steam.

[0063] like Figure 3 As better shown in the figure, the water level sensor 6 is fixed on the outer surface of the upper cover 3b of the boiler 3, so that the upper part 6a of the sensor 6 protrudes outside the boiler 3, and the lower part 6b of the sensor 6 is located in the second upper part 7b of the space inside the boiler 3, where usually only steam (not water) exists.

[0064] The outer surface of the boiler 3 is also fixed with a water inlet 8 for introducing water into the boiler 3, a water outlet 9 for discharging water from the boiler 3, and a solenoid valve 14 for allowing steam to be discharged from the boiler 3, and is also combined with a safety valve 14a designed to release pressure in the event of a system failure.

[0065] A plate 10, which is made of die-cast aluminum, is fixed to the bottom surface of the lower cover 3a of the boiler 3. A resistor 5, in the form of a die-cast ring, is fixed to this plate 10 and heats the boiler 3 when it is activated.

[0066] The second sensor 11 , which is also fixed on the plate 10 , independently of the water level sensor 6 , is fixed in contact with the bottom surface of the lower cover 3 a of the boiler 3 , and regulates the temperature of the boiler and thereby the temperature of the plate 10 .

[0067] A thermal limiter 12 and a thermal fuse 13 are also fixed to the board 10 and are connected in series with the resistor 5 as redundant electrical safety devices to interrupt the current path when the sensor 11 or an electronic board suitable for cooperating with the sensor 11 has a temperature regulation problem.

[0068] Figure 4 Also schematically represented is the electronic board equipped with a microprocessor 17 capable of cooperating with the sensor 11 and the water level sensor 6 .

[0069] The system provides that when the water level sensor 6 detects a temperature higher than a predetermined threshold, the microprocessor 17 activates the pump 4 to provide a certain amount of cold water from the water tank 2 to the boiler 3 to keep the water level within a predetermined range.

[0070] Furthermore, there is a button 20 on the device 19 which, when pressed, activates the solenoid valve 14, allowing steam to be discharged from the boiler 3, the steam reaching the device 19 through the pipe 18, the device utilizing steam, such as an iron, or a device for cleaning objects selected from the group consisting of floors, carpets, armchairs, curtains and glass, etc.

[0071] Example

[0072] The device 1 of the utility model is used with water having a hardness of 30 French degrees, wherein 1 French degree corresponds to 10 mg of CaCO3 per liter of water.

[0073] It has been found that the water level sensor 6 used in the device 1 of the present invention lasts an average of about 400 liters in the part of the boiler 3 where only steam usually exists, i.e. the upper part 7b of the space inside the boiler 3. After that, the water level sensor 6 must be replaced because it can no longer function properly.

[0074] On the contrary, in the portion of the boiler 3 where only water normally exists, namely, in the lower portion 7a of the space in the boiler 3, a similar water level sensor 6 is placed, and its average life is about 180 liters.

[0075] This indicates that the water level sensor 6 in the device 1 of the present invention, in a portion of the boiler 3 where only steam is normally present and therefore not in contact with water, has a longer life than a similar sensor immersed in water or in direct contact with water.

[0076] Of course, many modifications and variations to the described preferred embodiments will be apparent to those skilled in the art while remaining within the scope of the invention.

[0077] Therefore, the present invention is not limited to the preferred embodiments described, which are presented for purposes of illustration and not limitation, but are defined by the following claims.

Claims

1. A household appliance (1) for generating steam, the household appliance (1) comprising: - a water tank (2) which is at atmospheric pressure; - a boiler (3) suitable for containing water to be evaporated up to a predetermined water level, wherein the internal part of said boiler (3) is divided into a first lower part (7a) occupied by water, and a second upper part (7b) above said first lower part (7a) occupied by steam, and wherein said boiler (3) is composed of a lower cover (3a) and an upper cover (3b) connected to each other to form therein said first lower part (7a) and said second upper part (7b) of the boiler (3); - means for conveying water (4) from said water tank (2) to said boiler (3); - a heating source (5) for evaporating the water; - a water level sensor (6); - a control device adapted to maintain the water level in the boiler (3) within a predetermined water level range, wherein the control device is adapted to cooperate with the water level sensor (6) and to operate the device for supplying water (4) to supply a certain amount of water to the boiler (3) when the water level sensor (6) detects a temperature above a predetermined threshold value, The water level sensor (6) is arranged such that at least a part of the water level sensor (6) is located in the second upper part (7b) of the boiler (3). It is characterized in that the household appliance (1) for generating steam further comprises a plate (10) fixed to the bottom surface of the lower cover (3a) of the boiler (3).

2. The household appliance (1) for generating steam according to claim 1, characterized in that The water level sensor (6) comprises an upper portion (6a) fixed to the outer surface of the upper cover (3b), and a lower portion (6b) located in the second upper portion (7b) of the boiler (3).

3. The household appliance (1) for generating steam according to claim 1, characterized in that It also includes a water inlet (8) for entering the boiler (3).

4. The household appliance (1) for generating steam according to claim 1, characterized in that It also includes a water outlet (9) of the boiler (3).

5. The household appliance (1) for generating steam according to claim 1, characterized in that A second sensor (11) is also included to regulate the temperature of the boiler (3) heated by the plate (10).

6. The household appliance (1) for generating steam according to claim 1, characterized in that A thermal limiter (12) is also included.

7. The household appliance (1) for generating steam according to claim 1, characterized in that A thermal fuse (13) is also included.

8. The household appliance (1) for generating steam according to claim 1, characterized in that Also included is a device (14) for conveying steam from the boiler (3) to a steam user device (19).

9. The household appliance (1) for generating steam according to claim 8, characterized in that The steam user device (19) is an iron, or an electrical appliance for cleaning items, the electrical appliance being selected from the group consisting of floors, carpets, armchairs, curtains, and glass.

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