WO1993019237A1

WO1993019237A1 - Steam iron with device for detecting and removing scale

Info

Publication number: WO1993019237A1
Application number: PCT/FR1993/000279
Authority: WO
Inventors: Jean Daniel Vergnes
Original assignee: Superba
Priority date: 1992-03-20
Filing date: 1993-03-19
Publication date: 1993-09-30
Also published as: FR2688807B1; FR2688807A1

Abstract

Steam iron comprising an evaporation area (7) receiving water from a reservoir (5) via an injecting device, and feeding steam to a distributing chamber (4) from which the steam can be used; a scale detecting device (8) through which passes fluid circulating in the evaporation area (7), said device (8) generating information on the volume of scale build-up in said area; and a deviation circuit (9) for disconnecting, based on this information, the evaporation area (7) from the distributing chamber (4) so as to descale the appliance by means of a descaling liquid poured into the reservoir (5) and evacuated to an outer element connected to the deviation circuit (9), the descaling liquid passing through the evaporation area (7) but not the distributing chamber (4). The area includes either a calibrated water inlet port (11) or a calibrated steam vent (12), so that the volume of scale building up therein is sufficiently small as to ensure that the descaling product has an effect.

Description

Steam ironing device fitted with a scale detection and removal device

The present invention relates to household electrical appliances such as steam irons or ironing presses, for example, provided with a scale detection device and removal of scale accumulated during their operation.

Such steam devices mainly consist of a water tank comprising a filling duct and communicating with a chamber

10 vaporization and distribution by a water injection device, this chamber having outlet orifices for the distribution of the vapor created by the heating of the water in the tank.

It is known that the use of such steam devices poses many problems, the most important being that resulting from the deposit of scale, linked to the

15 vaporization of the reservoir water, accumulated mainly at the level of the device for injecting the reservoir water and incidentally in the vaporization chamber or on the outlet orifices of this chamber.

The current solutions to this scaling problem are multiple but not at all satisfactory.

A first solution simply consists in directly introducing the water from the reservoir into the vaporization and distribution chamber in order to allow, under the effect of the thermal shock thus created, the evacuation through the outlet orifices of the impurity chamber. and various residues such as the mineral deposits accumulated in this chamber. However, when scaling is

25 important, this method proves to be insufficiently effective and obliges after a certain time the replacement of the vaporization and vapor distribution chamber. Furthermore, its effectiveness depends very much on the time when descaling is carried out, the simplest, but not the best, being the instant defined by the stopping of steam production due to scaling at the outlet ports of the

_3Û vaporization chamber.

Another solution consists in using an anti-tartar cassette which by ion exchange traps the mineral deposits contained in the water and thus softens it for vaporization. However, this cassette must be replaced frequently, in practice once a month for water of medium hardness, this

35 which is restrictive for the user and also particularly expensive. Yet another solution consists in using an anti-scale rod which provides a mechanical unblocking of the water injection device disposed between the tank and the vaporization chamber. However, this device does not prevent the deposit of scale inside the chamber or at the outlet orifices thereof. The invention aims to overcome these drawbacks and to provide a device for removing scale in an apparatus of the type described above, which can be used with ordinary water and does not require the change of the vaporization chamber.

Another object of the invention is to indicate precisely to the user the most favorable moment for carrying out descaling.

These aims are achieved by a steam device characterized in that it comprises an evaporation zone receiving, from an injection device, the water from a tank and delivering steam for a distribution from which this steam is exploited; a tartar detection device crossed by the fluid passing through the evaporation zone and generating characteristic information of the volume of tartar accumulated in this zone; and a bypass circuit allowing a user, from taking this information into account, to decouple the evaporation zone from the distribution chamber in order to ensure descaling of the appliance by means of a descaling liquid introduced into the tank and discharged to an external member connected to the bypass circuit, this descaling liquid passing through the evaporation zone, but not the distribution chamber.

The independence of the evaporation zone and the distribution chamber, located directly at the place where the steam is used (iron soleplate or press plate), makes it possible to descale and rinse the evaporation zone, through the bypass circuit, without affecting this vapor distribution chamber.

The evaporation zone has an inlet or outlet port calibrated so that the scale builds up on it in a volume small enough to allow an effective action of a descaling product.

These orifices make it possible to create at a precise and predetermined location a scaling zone, the control of which is then facilitated by the use of a scale detection device, placed upstream or downstream of this zone.

The detection device may consist of a pressure gauge indicating the level of the pressure entering the evaporation zone and showing the crossing seed of this level beyond a predetermined pressure setpoint or else into a flowmeter indicating the level of steam flow leaving the evaporation zone and visualizing the crossing of this level below a predetermined flow setpoint. Thanks to these systems, it is then easy to indicate, for example by means of a marker or an audible alarm, the moment when the user must carry out the maintenance of his device by injecting a descaling product then by rinsing.

The bypass circuit comprises a body provided with an inlet duct connected to the outlet opening of the evaporation zone, an outlet duct connected to the inlet of the distribution chamber and a duct flow can be connected to an external member, a shutter element allowing either to ensure a passage of steam from the evaporation zone to the distribution chamber via the inlet and outlet conduits, the flow conduit being closed, ie ensuring a direct connection between the evaporation zone and the external member, the outlet conduit being in turn blocked.

This bypass circuit thus allows evacuation of the steam or of a descaling liquid without affecting the area of use of the steam.

Advantageously, it can also allow the use of a second steam use zone from the same evaporation zone.

Other characteristics and advantages of the present invention will emerge more clearly from the following description, without implied limitation, with reference to the appended drawings in which:

FIG. 1 is a simplified representation of an autonomous steam ironing machine,

FIG. 2 is a simplified representation of a steam ironing apparatus with a separate steam generator,

- Figure 3 shows an embodiment of an evaporation zone used in the steam devices of Figures 1 and 2, - Figure 4 is an exemplary embodiment of a tartar detection device used in an apparatus for steam according to the invention, and

- Figures 5 to 7 are examples of embodiment of a bypass circuit of a steam device according to the invention.

Figure 1 shows an elevational view with a cutaway portion of an autonomous steam ironing apparatus. Conventionally such a steam appliance .1 comprises a sole 2 in which channels 3 are produced for the evacuation of the steam coming from a distribution chamber 4 which also functions as a vaporization chamber. A tank 5 receives a filling conduit 6 with water which will then be injected into this chamber to be heated by heating means, not shown, generally heating resistors, and produce steam available to the user. .

In the device according to the invention, the functions of vaporization and of distribution of the vapor are separated and implemented in two distinct zones. Thus, the steam device according to the invention comprises, in addition to the distribution chamber 4, an evaporation zone 7, a scale detection device 8 and a bypass circuit 9. The scale detection device 8 is placed between an outlet 10 of the tank-water injector assembly 5 and a water inlet orifice 11 of the evaporation zone 7 and the bypass circuit 9 is arranged between a steam outlet orifice 12 of this evaporation zone 7 and an inlet 13 of the distribution chamber 4.

A cable 14 for the supply of electrical power enables the heating resistors to be energized and therefore the production of steam.

FIG. 2 shows an elevation view with a part cut away of another embodiment of a steam ironing apparatus according to the invention, in which the generation of steam is carried out independently from operation or the use of this vapor.

The iron proper 15 or the iron press only has the distribution chamber 4 with its steam diffusion channels 3 passing through the sole 2. This assembly which ensures the exploitation of the steam, is completely independent of the steam production zone constituted by a steam generator 20. This comprises, as for the autonomous steam appliance described above, a tank-water injector assembly 5, a scale detection device 8, a zone evaporation 7, and a bypass circuit 9. The water supply to the reservoir 5 can be carried out manually by the filling duct 6, but this requires frequent filling, or else continuously by means of a nozzle. 16 connected to a water supply network. The injection of water into the evaporation zone 7 can be carried out simply by a pump placed at the level of the reservoir 5. A flexible conduit 21 provides the connection between the steam generator 20 and the steam operating assembly 15. If necessary, other conduits, including for example a flexible conduit 22 mounted between the evaporation zone 7 and the branch circuit 9, can also provide connections between the different elements of the steam generator 20.

The main objective of irons or steam ironing presses is to achieve a significant steam flow rate to ensure quality ironing with the shortest possible execution time. A major obstacle to this objective, which arises as soon as there is vaporization of water, is the deposit of tartar, the volume of which essentially depends on the hardness of the water used. Thus, in certain regions the lifespan of conventional stand-alone irons can be limited to 6 months. The use of a demineralizing anti-tartar cassette allows an increase in this lifespan, but does not provide a complete solution to the problem of scaling. This is achieved by the invention which combines a drainage system which closes the inlet of the distribution chamber allowing the evacuation of a descaling product without access to it, a calibration of a determined access of the evaporation zone making it possible to locate the deposit of lime scale in small volume to make the descaling product operative, and a detection device reacting to the reduction in the passage of water or steam at the predetermined access and actuating warning devices to indicate to the user the need to carry out a descaling operation.

If we again consider for example FIG. 2, the water is introduced through the filling orifice 6 into the steam generator 20 and then injected by the injection device of the tank-injector assembly 5 into the area evaporation 7 after passing through the scale detection device 8. The amount of water injected into the evaporation zone 7 is of course adapted to the heating capacity of the steam generator 20 so that the water injected is immediately vaporized. The vapor produced is then evacuated through the outlet orifice of the vaporization zone 7 towards the apparatus for consumption or exploitation of the vapor, an iron or an ironing press 15 for example, through the bypass circuit 9 which also acts as a drainage system. In fact, when the scale detection device 8, the structure and operation of which will be described with reference to FIG. 4, detects an excessive presence of scale at the input of the evaporation zone 7, it signals to the user, by means of visual or audible indicators or by stopping the electrical supply 14 of the steam generator, the need to carry out the descaling of this area. From this moment, the user can carry out the maintenance by moving the bypass circuit 9, as will be explained further with reference to FIGS. 5 to 7, to isolate the distribution chamber 4 from the consumption device. steam 15 from the steam generator 20 and in particular from the evaporation zone 7, then by introducing in place of the water a descaling liquid which will ensure the emptying of the device and will destroy the deposits of tartar accumulated in this zone d 'evaporation, mainly at the inlet or outlet thereof. A subsequent rinsing will then restore the evaporation zone 7 to its initial state and allow, after a replacement of the bypass circuit 9, a new use.

This regular maintenance as a function of the volume of scale detected by the detection device 8 considerably increases the life of the steam appliance because it is not carried out, as is currently the case after the consumption of a certain predetermined quantity of water, which does not take into account the quality of the water which can be more or less demineralized according to the regions, or simply when the diffusion of the vapor is no longer possible through the steam evacuation channels.

FIG. 3 represents the evaporation zone 7. The shape thereof is indifferent but it can advantageously be in the form of a closed cylinder comprising, on an upper part 70, the water inlet orifice 11 of a section calibrated so that it closes on a volume low enough to allow easy and effective descaling, and on a lower part 71 The steam outlet orifice 12. As an alternative to the orifice of calibrated water inlet, it is possible to make the steam outlet 12 also calibrated. The closure of the calibrated orifice 11 or 12 is identified by the scale detection device 8, an exemplary embodiment of which is given in FIG. 4.

This device disposed between the water injection system of the reservoir-injector assembly 5 and the evaporation zone 7, comprises an element 81, placed in the flow of the liquid coming from the injection device 5, and in communication with a measuring assembly 83 consisting of two parts 84, 85 separated by an elastic membrane 86 arranged parallel to the flow of liquid. A metal strip 87 rests on this elastic membrane 86 and is in contact with a spring 89 integral with the upper part 85. Two electrical contact pads 88 are also inserted in this upper part 85. When, after several hours of use, the diameter of the calibrated orifice becomes reduced under the effect of the accumulation of scale, the overpressure created at the level of the measuring device 83 causes a deformation of the elastic membrane 86, opposite to the fluid. When this overpressure is greater than a reference value defined by the tension applied to the spring 89, the metal strip 87 comes into contact with the studs 88 and thus establishes an electrical connection which is advantageously used to warn the user that a descaling operation becomes necessary.

It can be noted that the scale detection device 8 could consist simply of a pressure gauge, the indicator of which would indicate the pressure reached at the level of the inlet of the evaporation zone 7 and would indicate, by a visual reference, the need for 'a descaling. Likewise, consideration may be given to the use of a flow meter which would indicate the flow rate reached in the conduit for supplying water to the evaporation zone 7 and would also indicate the need for descaling. The use of visual indicators is not exclusive, audible indicators can also be used and it is also possible to warn the user by cutting off the power supply to the steam appliance.

It should also be noted that the arrangement of the detection device 8 upstream of the evaporation zone 7 is not compulsory and that it can also be placed on the steam circuit downstream of this zone 7 before the bypass 9 which will now be described with reference to FIGS. 5 to 7.

The branch circuit 9 is in the form of a connecting piece 90 advantageously cylindrical provided with a first axial access 91 and a radial access 92, the second axial access being closed by a shutter 93. The first axial access 91 is connected to the steam outlet orifice 12 of the evaporation zone 7 and the radial access 92 is connected to the distribution chamber 4. The shutter 93 is pierced with several openings, for example 94 to 97, in order to allow it to perform different functions.

Thus, in the position of FIG. 5, which is the normal operating mode of the steam appliance, the steam produced in the evaporation zone 7 is directly transmitted to the distribution chamber 4 through a radial opening 94 of the shutter 93 located in correspondence with the radial access 92.

In the position of FIG. 7, which is a second normal operating mode of the steam appliance more particularly applicable to a steam appliance of the type of FIG. 2 having a separate steam generator, the steam produced by a single evaporation zone 7 can be transmitted simultaneously to two distribution chambers 4 of two irons or pressed to be ironed independently thanks on the one hand to the radial openings at the ends 95 and 97 and on the other hand to a rotation and a partial withdrawal of the shutter 93 to bring the radial opening 96 in correspondence with the radial access 92, the radial end openings 95 and 97 then being located outside of the connecting piece 90.

Finally, the position of FIG. 6, shows a mode of operation in descaling in which the radial access 92 is closed and the shutter 93 is partially removed revealing the radial openings of ends 95 and 97. In this mode of operation , the descaling liquid after having circulated in the evaporation zone 7 is discharged to the outside without affecting the vapor distribution chamber 4.

It should be noted that this mode can also be used in the presence of steam and allows for example an alternative supply of an external organ. It can also be noted that a plug can be placed at the second axial access to replace the shutter 93, the emptying then being carried out simply by removing this plug and then by introducing a conduit for evacuation of waste water in the connecting piece 90, which conduit then closes the radial access 92 of this piece.

Claims

1. Steam appliance, characterized in that it comprises: an evaporation zone (7) receiving, from an injection device, water from a tank (5) and delivering steam for a room distribution (4) from which this

5 steam is used; a scale detection device (8) traversed by the fluid passing through the evaporation zone (7) and generating information characteristic of the volume of scale accumulated in this zone; and a bypass circuit (9) allowing a user, from taking this information into account, to decouple the evaporation zone (7) from the distribution chamber (4) in order to ensure 10 a descaling of the appliance by means of a descaling liquid introduced into the tank (5) and discharged to an external member connected to the bypass circuit (9), this descaling liquid passing through the evaporation zone (7), but not the distribution chamber (4).

2. Steam appliance according to claim 1, characterized in that the evaporation zone (7) has a water inlet orifice (11) calibrated so that the scale builds up thereon in a volume low enough to allow an effective action of the descaling product.

3. Steam appliance according to claim 1 ,. characterized in that the evaporation zone (7) has a vapor outlet orifice (12) calibrated so that

20 the scale builds up thereon in a sufficiently small volume to allow an effective action of the descaling product.

4. Steam appliance according to claim 1 and claim 2, characterized in that the scale detection device (8) is placed upstream of the evaporation zone (7) and detects an elevation, beyond a pressure of

25 predetermined reference, of the pressure at the inlet of the evaporation zone (7) due to a blockage of the water inlet orifice (11) of this zone.

5. Steam appliance according to claim 1 and claim 3, characterized in that the scale detection device (8) is placed upstream of the evaporation zone (7) and detects an elevation, beyond a pressure of

-30 predetermined reference, of the pressure at the inlet of the evaporation zone (7), due to a blockage of the vapor outlet orifice (12) of this zone.

6. Steam appliance according to claim 4 or claim 5, characterized in that the detection device consists of a pressure gauge indicating the level of the pressure entering the evaporation zone (7) and

35 showing that the predetermined reference pressure has been exceeded.

7. Steam appliance according to claim 4 or claim 5, characterized in that the scale detection device (8) comprises a measuring assembly (83) consisting of an upper part (85) and a lower part (84) separated by an elastic membrane (86) arranged parallel to the flow of the

5 liquid passing through the device and on which rests a metal strip (87), two electrical contacts (88) inserted in this upper part (85) allowing the establishment of an electrical connection when, under the action of higher pressure at the predetermined reference pressure defined by a spring (89) disposed between the metal strip (87) and the upper part (85), the metal strip (87) comes into contact with the electrical contacts (88).

8. Steam appliance according to claim 1 and claim 2, characterized in that the scale detection device (8) is placed downstream of the evaporation zone (7) and detects a decrease, below a predetermined reference flow rate, of the steam flow rate at the outlet of the evaporation zone (7), due to a

15 closing the water inlet orifice (11) of this zone.

9. Steam appliance according to claim 1 and claim 3, characterized in that the scale detection device (8) is placed downstream of the evaporation zone (7) and detects a decrease, below a predetermined reference flow rate, of the steam flow rate at the outlet of the evaporation zone (7), due to a

20 closing of the steam outlet orifice (12) of this zone.

10. Steam appliance according to claim 8 or claim 9, characterized in that the detection device consists of a flow meter indicating the level of the steam flow at the outlet of the evaporation zone (7) and showing the overflow of the predetermined reference flow.

11. Steam appliance according to any one of claims 6, 7 or

10, characterized in that crossing the threshold defined by the predetermined reference setpoint causes either the operation of a visual or audible indicator or the cut off of the water or electricity supply to the evaporation zone. _3G

12. Steam appliance according to any one of claims 1 to 11, characterized in that the bypass circuit (9) comprises a body (90) provided with an inlet duct (91) connected to the orifice of steam outlet (12) from the evaporation zone (7), an outlet duct (92) connected to the inlet (13) of the distribution chamber (4) and at least one flow duct (95, 97) can be connected to an organ

35 external, a closure element (93) allowing either to ensure a passage of the vapor from the evaporation zone (7) to the distribution chamber (4) via the inlet (91) and outlet (92) conduits, the flow conduit (95, 97) being closed, or to provide a direct connection, via the flow conduit (95, 97), between the evaporation zone (7) and the external member, the outlet conduit (92) being in turn closed.

13. Steam appliance according to claim 12, characterized in that the shutter element (93) allows the passage of steam from the evaporation zone (7) both to the distribution chamber (4) by through the outlet conduit (92) and to the external member through the flow conduit (95, 97).