EP0660914B1 - Evaporation chamber with anti-calefaction layer - Google Patents

Description

TECHNICAL AREA

The present invention relates to the technical field apparatus for vaporizing fluids and in particular field of steam irons.

The present invention relates on the one hand to a layer anti-calefaction provided in a vaporization chamber, and on the other hand a method of manufacturing such a layer also intended for spraying an ironing liquid, usually the occurrence of water.

PRIOR ART

It is already known in the prior art to produce anti-caulking layers, in particular by providing special coatings sprayed or applied with a brush such than sodium silicate, ceramic solutions, silicate or silica. These coatings are generally applied in vaporization chambers.

These or other equivalent products are known for their hydrophilic and wettability properties ensuring spreading and diffusion of water on the bottom of the vaporization chamber. This gives better water vaporization, resulting in a decrease of the emission of water in liquid form through vapor outlets located under the soleplate of a iron for example.

It is also known to use fiber fabrics mineral or synthetic, arranged in the vaporization. Tissues are usually held in place by means mechanical. These consist of springs, rivets or a grid of maintenance.

We also know the document DE-A-3006783, in which a steam chamber of an iron is provided at its bottom with a wire mesh made using metal wires. The latter may, as the case may be have ends inserted into the bottom of the vaporization chamber, for mechanical strength purposes.

Document US-A-3218741 describes a treatment of a surface of a vaporization chamber, to which a layer based on mica, partially overmolded in the bottom of the vaporization chamber, with a particular binding element of the alumina type.

We also know, using a number of documents, and in particular with the help of document GB-A-2077624, to provide the chambers with vaporization of an iron with a silicon-based coating, to limit the phenomenon of calefaction.

The various solutions provided by the prior art do not allow however, to sufficiently limit the heat build-up in the vaporization. The caulking usually occurs by bringing a liquid on a very hot surface. Spraying a small amount of liquid on such a surface causes the appearance of drops moving randomly on said surface and which are only vaporized after a time interval relatively large. Contact between a drop of liquid and the surface hot generates steam which lodges between said surface and the base of said drop directed towards this surface. The vapor cushion thus formed promotes displacement of the drop on the hot surface and considerably reduces the vaporization.

The phenomena of caléfaction increase the duration of vaporization and therefore decrease the effectiveness of known coatings. These, in in particular, sprayed coatings have poor resistance to the acidity present often the fluid to evaporate. This is particularly the case for water.

Known coatings of the sodium silicate type or other products equivalents also have a resistance which can be qualified insufficient for thermal shock and limited adhesion to the bottom of the vaporization chamber. We can also note a marked trend towards dissolution of these products in water thus greatly reducing the lifespan irons.

In addition, the tissue fibers used in the prior art are maintained in place through various mechanical means. These latter significantly increase the complexity of manufacturing or realization of said vaporization layers. Otherwise, this more complicated realization is linked to the use a larger number of pieces. These different factors are the source of a significant manufacturing cost. this is especially the case when manufacturing iron soles ironing with a vaporization chamber fitted with a such coating.

The object assigned to the invention therefore aims to remedy the various drawbacks listed above and to provide a vapor generating device whose spray quality is improved.

The object of the present invention is to provide a steam generating device comprising a spraying with a spraying bottom allowing quickly vaporize a liquid by limiting the phenomenon of caulking.

The object of the present invention also aims to provide a steam generating device which exhibits, in addition to a reduction in the phenomenon of heat build-up, a background almost insensitive to possible acidity of the liquid intended to be vaporized.

Another object of the present invention is to provide a bottom of a mechanically resistant spray chamber and secured with an iron soleplate for example, without the use of additional mechanical means.

Another object of the present invention is to provide a steam generating device including the vaporization has an insensitive anti-caulking layer thermal shock and adhering well to the bottom of said chamber so as to ensure optimal heat transfer.

The invention also aims to provide a method simple and effective production of an anti-calefaction layer in a vaporization chamber of a device for generating steam.

An additional object of the invention aims to provide a generation device efficient and reliable steam whose manufacturing cost is significantly reduced and whose lifespan is increased at the same time.

STATEMENT OF THE INVENTION

The objects assigned to the invention are achieved by means of a device for generation of steam comprising a heating means in thermal relation with a vaporization chamber, a liquid reservoir communicating with the vaporization chamber, which has a bottom against which the liquid intended to be evaporated, said bottom comprising a zone defining a surface layer of a thermal conductive material inside the vaporization chamber, characterized in that the layer has over its entire surface of partially hydrophilic and thermally insulating fibers and locally embedded in the thermal conductive material of the layer.

The objects assigned to the invention are also achieved by means of a process for producing a bottom of a vaporization chamber consisting of use thermally insulating and hydrophilic fibers and a material thermally conductive aluminum type characterized in that it consists of intimately bond the fibers with the bottom in a layer of a surface area of said bottom, so as to ensure a thermal transfer between the material thermally conductive, constituting the bottom, and the layer, said material partially impregnating said fibers.

SUMMARY DESCRIPTION OF THE DRAWINGS

• la figure 1 représente une vue transversale en coupe, d'un fond d'une chambre de vaporisation d'un dispositif de génération de vapeur conforme à l'invention.
• la figure 2 représente une vue transversale en coupe d'une variante de réalisation d'un fond d'une chambre de vaporisation.

The characteristics and advantages of the invention will emerge more clearly on reading the description given below by way of nonlimiting example, with reference to the appended drawings in which:

• Figure 1 shows a cross-sectional view of a bottom of a vaporization chamber of a vapor generation device according to the invention.
• 2 shows a cross-sectional view of an alternative embodiment of a bottom of a vaporization chamber.

BEST WAY TO IMPLEMENT THE INVENTION

As an example of implementation, reference will be made to steam irons.

The steam generating device (not shown in the figures) has a vaporization chamber (not shown in the figures), into which the liquid to vaporize, from a tank. This last includes for example an exit to the right of an impact zone on a bottom 3 of the vaporization chamber. The bottom 3 is made of a thermally conductive material 2 and metalogical preference. Advantageously, the material 2 is either aluminum, an alloy comprising aluminum.

In the embodiment shown in Figure 1, the bottom 3 has fibers 1 in a surface area woven, hydrophilic and insulating properties thermally at least partially and locally embedded in the material 2, constituting the bottom 3 and therefore a surface layer A of said bottom 3.

Advantageously, the surface area thus produced extends over at least part of at least one wall of the vaporization chamber, said wall facing a spray liquid inlet port.

Layer A therefore partly comprises fibers 1 to less partially and locally impregnated with the material constituting layer A. The latter is well obviously located inside a vaporization, opposite an orifice intended to inject a liquid in said vaporization chamber.

Fibers 1 penetrate at least partially and locally in layer A. Fibers 1 are of this way integrated in places in the constituent material 2 from the bottom 3.

The latter therefore comprises a surface layer A in which are locally embedded fibers 1 arranged between they for example in meshes.

According to a preferred embodiment of a room vaporization of a device according to the invention, the fibers 1 are overmolded in layer A. When the material 2 is solidified after the operation of overmolding, the fibers 1 are partially embedded in said material 2 and partly visible. Some are on a portion of their length is completely embedded in the material 2, or partially embedded in material 2, either completely visible and free from the material 2. Others are embedded in material 2 for a large part of their length, or completely freed from said material 2.

These different cases are distributed randomly in the area of the bottom 3. Indeed by through weaving or meshing of said fibers 1 le material 2 permeates locally, partially or completely the fiber fabric 1 thus produced. Weaving or mesh is thus effectively maintained in a layer A bottom surface 3.

The bottom 3 is thus secured to the fibers 1 in a surface area corresponding to layer A.

The assembly thus exhibits rigidity and solidity adapted to the mechanical constraints of the expansion type and contractions due to temperature variations. Layer A heterogeneous thus absorbs shocks satisfactorily very frequent thermal in an iron soleplate.

The phenomenon of caulking which generally occurs on spray surfaces is reduced on the one hand by the use of hydrophilic fibers 1 and on the other hand by a reduced heating temperature on the surface area of the background 3.

Indeed, said surface area consists of two materials, one thermally insulating, of the fiber type ceramics, the other thermally conductive of the type aluminum for example.

Impregnation of fibers 1 made of ceramic material causes a slight drop in temperature on the surface against which is brought the liquid to be vaporized by relative to the temperature of the material 2 constituting the bottom 3. Layer A thus acts as a light heat shield.

The heterogeneous layer A also has a surface, on which the liquid intended to be vaporized is led, it is largely made up of fibers 1 hydrophilic, preferably woven, which absorb and at least partially diffuse the liquid and / or soak up of said liquid in said layer A. The temperature drop at the bottom surface 3 and the hydrophilic properties and wetting agents help reduce the phenomenon of heat build-up. As a result the vaporization is improved and accelerated.

According to an alternative embodiment of the conforming device to the invention and shown in FIG. 2, layer A is consisting of an additional metal plate B linked intimately to an iron sole for example, which is thermally conductive.

Plate B, for example made of aluminum, is maintained in thermal and mechanical contact with the sole 3a by crimping or any other means.

Advantageously, the sole 3a is an iron sole with iron, and the plate B is molded onto said sole.

The anti-caulking layer thus produced on the bottom 3 inside the vaporization chamber has preferably hydrophilic woven and insulating fibers 1 thermally.

The fibers 1 used to partially produce the layer A in the vaporization chamber are, according to a variant of realization of the device, according to the invention, fibers hydrophilic, mineral hydrophilic or synthetic ceramics hydrophilic.

By way of nonlimiting examples, fiber yarns of glass, or composed of a mixture of metal and silica are perfectly suitable, as are fibers carbon or organic.

According to an additional alternative embodiment of a device according to the invention, the device steam generation involves a weaving of at least two different types of fibers. As such, we can consider to use in combination with hydrophilic fibers and thermally insulating of metallic fibers. It is obvious that the weaving of said fibers is only a variant preferential realization of the device for generating steam according to the invention.

According to another alternative embodiment of a device according to the invention the fibers are used nonwoven.

The use of other materials such as good metal thermal conductor is possible to realize the bottom 3, these are in particular alloys comprising aluminum. Obviously, any material intended to make a sole iron may be suitable for making a vaporization of a compliant steam generator to the present invention.

The present invention also relates to a method of production of a bottom 3 of a vaporization chamber of a steam generating device. The process consists of use thermally insulating and hydrophilic fibers 1 as well as a thermally conductive material, of the type aluminum to make a surface layer A of a bottom 3.

The method consists in intimately bonding the fibers 1 with the bottom 3 in a layer A of a surface area of said bottom 3, so as to ensure heat transfer between said bottom 3 and layer A.

According to a preferred embodiment of the process, the fiber fabric 1 is placed inside a mold before injection of a molten material 2. The link intimate mechanics between the fiber fabric 1 and the bottom 3 is thus produced directly by overmolding. Before the solidification of the molten material 2, the latter permeates at least partially and locally the fibers 1 in a superficial layer A of the bottom 3. The mechanical fixing of the fibers 1 is thus reached and ensured. The material 2 also has a surface 4 located opposite the layer A which performs the functions of an iron soleplate iron.

According to a variant of the process for producing a bottom 3 of a vaporization chamber, the intimate connection between the fibers 1 and bottom 3 is done through a metallic plate B used as interface between fibers 1 and the sole 3a. One of the process steps consists in intimately bind the fibers 1 with the metal plate B by example by overmolding.

As a variant, it can be envisaged to securing the fibers 1 with the plate B via a pressing or crushing step.

It is also envisaged, according to a variant additional method of making a bottom 3 of a vaporization chamber according to the invention, to bind intimately the metal plate B with the sole 3a by overmolding.

Any other means of fixing plate B to the sole 3a allowing thermal transfer of energy from heating to plate B may also be suitable.

The step of overmolding the plate B on the sole 3a can thus be advantageously replaced by a step of crimping or bonding.

The sole 3a is preferably used directly as an iron soleplate.

The advantage of a steam generator according to the invention and manufactured in accordance with the realization of a vaporization chamber of said device, is that it improves the vaporization yield, especially in a steam iron, without as much increase the manufacturing cost.

Another advantage of a device for generating steam according to the invention is an increased screw life with respect to existing vaporization devices.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the field of devices for producing steam and including steam irons.

Claims (15)

1. Steam-generating apparatus including heater means in thermal contact with a steam-generating chamber, a tank of liquid communicating with the steam-generating chamber which includes a bottom (3) against which the liquid to be evaporated is directed, said bottom (3) including a zone defining a surface layer (A) of a thermally conductive material inside the steam-generating chamber, said apparatus being characterized in that the layer (A) has hydrophilic and thermally insulating fibers (1) disposed over its entire surface, the fibers being partially and locally embedded in the thermally conductive material of said layer (A).
2. Steam-generating apparatus according to claim 1, characterized in that the hydrophilic fibers (1) are overmolded in the surface layer (A).
3. Steam-generating apparatus according to claim 1, characterized in that the layer (A) is constituted by an additional metal plate (B) intimately bonded to a soleplate (3a), which is thermally conductive.
4. Steam-generating apparatus according to claim 3, characterized in that the mechanical bonding holding together the metal plate (B) and the hydrophilic fibers (1) is obtained by pressing or crushing.
5. Steam-generating apparatus according to any one of claims 1 to 4, characterized in that it includes hydrophilic fibers (1) that are woven and that are thermally insulating.
6. Steam-generating apparatus according to any one of claims 1 to 5, characterized in that it includes ceramic, inorganic, or synthetic fibers (1).
7. Steam-generating apparatus according to claim 6, characterized in that it includes a woven mat of fibers (1) that are of at least two different types.
8. A steam iron including apparatus according to any one of claims 1 to 7.
9. A method of making a bottom (3) of a steam-generating chamber, the method consisting in using thermally insulating and hydrophilic fibers (1) and a thermally conductive material of the aluminium type, said method being characterized in that it consists in intimately bonding the fibers (1) with the bottom (3) in a layer (A) of a surface zone of said bottom (3), so as to provide heat transfer between the thermally conductive material, making up the bottom (3), and the layer (A), said material partially impregnating said fibers (1).
10. A method according to claim 9, characterized in that it consists in intimately bonding the fibers (1) with the bottom (3) by means of a metal plate (B) used as an interface between the fibers (1) and a soleplate (3a).
11. A method according to claim 10, characterized in that it consists in intimately bonding the fibers (1) with the metal plate (B) by pressing or crushing.
12. A method according to claim 10, characterized in that it consists in intimately bonding the fibers (1) with the metal plate (B) by overmolding.
13. A method according to any one of claims 10 to 12, characterized in that it consists in intimately bonding the metal plate (B) with the soleplate (3a) of the steam-generating chamber by overmolding.
14. A method according to any one of claims 10 to 12, characterized in that it consists in intimately bonding the metal plate with the soleplate (3a) by crimping.
15. A method according to claim 9, characterized in that it consists in intimately bonding the fibers (1) with the bottom (3) directly by overmolding thereover, so that the material making up the bottom (3) impregnates said fibers at least partially and locally in a surface layer (A) of said bottom (3).

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