EP1146164B1 - Physico-chemical antiscaling device with a grid, for an iron - Google Patents

Abstract

Steam iron, contains scale inhibitor of silicone elastomer produced by hardening water vapor permeable-organosilicon compound with hydrophilic active substance and polyorganosiloxane composition in (part of) water channel. In a steam iron, at least part of the water channel contains a scale inhibitor of silicone elastomer, produced by crosslinking or hardening a water vapor permeable-organosilicon compound with a hydrophilic active substance and a polyorganosiloxane composition. Near the vaporization zone of a steam chamber with a metal heating element, the iron has a grid through which the steam flows, consisting of a metal differing from that of the sole plate.

Description

The present invention relates to steam irons where vaporization occurs from almost instantly. These devices have a lifetime limited by scaling of the vaporization chamber.

Many devices have been described for reducing the scaling of iron. Among one of the most efficient physico-chemical systems consists in diffuse a phosphorus product in water before its vaporization to prevent the crystallization of tartar in a hard form and allow its evacuation by the steam flow. Patent FR2757364 describes an embodiment of such a device where the diffusion of highly soluble sodium hexametaphosphate (HMPS) is controlled by a silicone matrix placed in the water circuit. However under the action of steam we see that the tartar partially agglomerates and comes off in flakes, friable of course, but which are evacuated in bundles in marking the laundry.

The particles could be retained in the vaporization chamber by a metal screen as suggested in patent DE3006783 or the patent JP60160999. Sifting can also occur in a version of the patent FR2696197 where a grid intended to improve the vaporization has its edges raised in the shape of a basin. However, the use of a screening screen alone eventually causes blockage of the vaporization chamber with very large scale hard that does not drain.

The invention below relates to an anti-tartar device extending the duration of life of a steam iron by allowing regular evacuation of scale under a powder form invisible to the user, and avoiding blockage of the chamber as well as iron vaporization channels.

Mainly the object of the invention is achieved by a steam iron having a circuit of water at least one compartment of which contains an anti-scale agent obtained by crosslinking or hardening of an organo system into a silicone elastomer water vapor permeable silica comprising a hydrophilic active material and a polyorganosiloxane composition, the iron further comprising, near of the vaporization zone of a chamber formed in a heating body metallic, a grid, of metallic nature different from that of the body of heating, crossed by the steam flow.

Preferably the hydrophilic active material is chosen from metaphosphates sodium or potassium.

It can be seen that no visible flake comes out of the vaporization holes of the sole even when the grid has holes with a hydraulic diameter of around two millimeters. Surprisingly, tartar does not accumulate in the vaporization chamber, or in the vaporization channels.

Preferably the grid is mounted clamped between two walls of the vaporization of the iron.

The process which allows the tartar to appear in very fine form and not visible at the exit of the iron is not clearly explained. One can think just that the flaky flakes coming off the spray area are retained and rub against the grid which breaks them. One can think that the tartar which is deposited on or against the grid breaks due to expansion and thermal contractions of the grid. We can also think of a phenomenon unknown resulting from the difference in electrical potential caused by natures different from the heating body, therefore from the vaporization chamber and the grid. This difference in potential could be exerted thanks to the link electric due to the clamping of the grid in the heating body.

Preferably the grid is coated with a layer of gold.

This layer protects the grid by making it stainless. We also see that it generates a large potential difference with a heating body in aluminum.

In another version, the grid is made of stainless steel.

The grid is protected from oxidation phenomena and creates a difference potential with an aluminum heating body.

Preferably the grid is made of expanded metal.

This arrangement helps break up the scale that comes to settle on or against the grid.

Preferably the anti-scale agent is contained in a tube and releases its material activated by at least one open end of the tube.

The silicone matrix can be molded into the tube without requiring any other mold. The active material is released with kinetics of order one by a progressive front of cracks in the matrix which corresponds to the section of the tube and which is therefore perfectly controlled.

Preferably the tube containing the anti-scale agent is placed in the tank iron water.

The anti-scale agent may be in sufficient quantity to ensure good operation during the life of the iron, or can be interchangeable. The disposal in the tank constitutes a simplification made possible by the molding in a tube.

The invention will be better understood on the basis of the example below and of the drawings attached.

Figure 1 is a simplified longitudinal section of an iron according to the invention.

Figure 2 is a simplified top view of the soleplate of an iron according to the invention.

In a preferred embodiment the iron shown in Figure 1 comprises a sole 1 having a vaporization chamber 2, a reservoir 3 of water to vaporize, a drip system 4 allowing the supply of water from the vaporization chamber 2 from the reservoir 3, and an envelope 5 comprising an iron handling handle.

The reservoir 3 formed of two parts 300 and 301 assembled has an orifice filling 302 closed by a sliding cover 303. Inside this tank is arranged a tubular element 304 of constant section in which a 305 silicone elastomer matrix is molded containing sodium hexametaphosphate (HMPS) in solid dispersion. This tube whose ends are open and reveal the silicone matrix 305 is placed so as to be wetted by the water contained in the tank.

The sole 1 comprises an aluminum heating body 100 which forms the walls from the vaporization chamber 2, a resistive tubular heating element 101, a closure plate 102 of the vaporization chamber 2, a cover 103 at the thermal contact with the heating body 100 and intended to be in contact with the linen ironed on its outside face with the iron.

The vaporization chamber 2 has a zone 200 more visible in FIG. 2 where the drop of water drops. The spray area widens on the dish of the sole in a region 201. This vaporization zone is closed by ribs 202 and by a grid 203 preferably made of plated expanded metal of a thin layer of gold. The grid 203 is mounted tightly between the plate closure 102 and the bottom of the vaporization chamber 2, so that the contact electric is provided between the plate 102, the grid 203 and the heating body 100. A potential difference is established between the grid 203 and the heating body 100, as a result of different metallic natures.

The grid has a mesh width of between 0.3 and 3 millimeters, the section of the mesh son preferably being angular, namely triangular, square or rectangular. The grid is made of a metallic material different from that the vaporization chamber, in particular stainless steel, if desired covered with a layer of gold with a thickness between 10µ and 100µ.

Advantageously, the bottom of the vaporization chamber 2 is covered by a anti-heat coating. The steam produced can escape through passages 206 and channels 204 to vaporization holes such as 205 which lead to the ironed linen directly or via other channels of distribution located under the soleplate.

The iron being at room temperature, the silicone matrix 305 diffuses only very little hexametaphosphate by its free ends, even if the silicone matrix 305 is wet. To use her iron, the user fills the water tank 3 with the orifice 302, the opening of which it closes with the cover 303. The iron being hot, the tank rises to a moderate temperature but sufficient to accelerate strongly the diffusion of HMPS in water, the vapor diffusing towards the grains of highly hydrophilic HMPS which take up water, swell and break the network silicone. The diffusion front of HMPS progresses slowly in the matrix in the axis of the tube along its constant section, and the diffusion is well controlled.

Preferably, the length and the section of the tube are provided to ensure the diffusion of anti-scale product during the lifetime of the iron. In an other version, the tube and its silicone matrix are interchangeable.

When the user returns, she acts on a command 40 to obtain steam on the laundry. The drip then lets water pass from the reservoir 3 charged in HMPS to vaporization chamber 2 where it drops to drop in an area 200, and spreads more or less widely, depending on the flow rate, in zone 201 of the room. The vaporization produces vapor which discharges to the laundry by passing through the grid 203, then passing through the passages 206 and channels such as 204 to join the spray holes 205 of the sole.

The large scale left by the vaporization of water is in the form pulverulent thanks to the action of the HMPS and is partially evacuated by the steam.

Another part of the scale sticks to the walls of the vaporization chamber 2 in friable layer from which it subsequently becomes detached. These tartar flakes are then retained by the grid. Another part of the tartar is deposited in a crust directly on the grid. Surprisingly, the flakes and crusts of scale disintegrate at the level of this grid essentially in fine powder invisible to the naked eye, this powder discharging out of the iron through the orifices steam. We think that the difference in electrical potential present at the level of the grid, of the order of 2 to 3 volts, causes a transformation of the cohesion crystals of tartar, this transformation can be completed by angular geometry of the grid frame section. Grid 203 is then sufficient to prevent the passage of large particles and to transform them into fine powder.

In another version the HMPS is replaced by another phosphorus product hydrophilic.

By these means the tartar is evacuated regularly invisibly and without disadvantage for the user. The life of the iron is increased by the anti-scaling hydrophilic product, without this product causing such disadvantages only stains marking the ironed laundry.

Claims (8)

1. A steam iron having a water circuit in which at least one compartment contains an anti-scale agent (305) obtained by cross-linking or hardening in a silicone elastomer, a steam-permeable organosilic-compound system comprising an active hydrophilic material and a polyorganosiloxane composition, the steam iron being characterized in that it further comprises, in the vicinity of the steam zone (200) of a chamber (2) formed in a metal heater body (100), a grid (203) of a metal that is different from the metal of the heater body (100), and through which the flow of steam passes.
2. A steam iron according to claim 1, characterized in that the active hydrophilic material is selected from amongst sodium and potassium metaphosphates.
3. A steam iron according to any preceding claim, characterized in that the grid (203) is force-fitted between two walls of the steam chamber (2) of the steam iron.
4. A steam iron according to any preceding claim, characterized in that the grid (203) is covered in a layer of gold.
5. A steam iron according to any one of claims 1 to 3, characterized in that the grid (203) is made of stainless steel.
6. A steam iron according to any preceding claim, characterized in that the grid (203) is made of expanded sheet metal.
7. A steam iron according to any preceding claim, characterized in that the anti-scale agent (305) is contained in a tube (304) and releases its active material via at least one open end of the tube.
8. A steam iron according to claim 7, characterized in that the tube (304) containing the anti-scale agent (306) is placed in the water tank (3) of the iron.

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