Device for discharging dry steam in the form of a pipe for equipping a steam cleaner

Description

[0001] The present invention relates to the field of cleaning and disinfection, whether for a professional or industrial environment, but also for a particular use.

[0002] The present invention relates more specifically to the household appliance field of steam cleaners.

[0003] Generally speaking, many types of steam cleaners are known in the state of the art, which are, conventionally, equipped with a storage tank intended to be filled with water, the latter being heated to a high temperature, typically between 70 and 120°C, by means of a boiler. Once the temperature is reached, the water is propelled, in the form of pressurized steam, out of the device, through a projection tube extended by a tip or a nozzle, in order to allow the cleaning of various surfaces, such as floors of all types, walls, windows, upholstery, carpets or rugs, etc.

[0004] We know in particular, from the English patent application published under number GB 2 537 918, a steam cleaning device allowing its user to clean surfaces with different orientations (floors, walls, etc.).

[0005] This apparatus is composed of two portions: a first portion which has a conduit extending along a first axis, which can be noted XX, as well as a second portion also having a conduit, extending along an axis which can be noted YY, the two axes XX and YY of the two conduits which make up the apparatus being in two different planes.

[0006] Thus, the path of the water vapor in this apparatus is complicated, and the vapor is slowed down, by a change of direction between the conduit of the first portion of the apparatus and the conduit of the second portion.

[0007] Also known from English patent application GB 408 859 is an apparatus for cleaning the surfaces of buildings, walls or monuments and which ejects a vapour containing aluminium sulphate, boric acid, sulphuric acid and hydrochloric acid.

[0008] Generally speaking, while such devices are particularly interesting and increasingly popular with industrialists and individuals, because they allow, easily and optimally, depending on the use, cleaning, descaling, stain removal, or disinfection of the surface to which the water vapor is applied, they have various disadvantages.

[0009] Thus, one of the main disadvantages of existing devices available on the market lies in the fact that, when the water vapor leaves the projection tube, in contact with air at ambient temperature, or a cold surface, the temperature of the vapor will decrease drastically, to around 70-90°C. Thus, part of the vapor will condense immediately at the exit of the ejection tube, and form water droplets which remain dispersed in the water vapor.

[0010] This phenomenon can have the consequence, in particular, depending on the surface treated with the device, of causing water runoff and / or significant and unwanted humidification of fabrics, which are sometimes difficult to dry subsequently due to their thickness, or even warping of joints.

[0011] Furthermore, the more water the steam contains in the liquid state (droplets), the less efficient it is from an energy point of view: it transports and provides less heat than saturated, or "dry" steam, which has a very high temperature and contains a proportion of water vapor of around 5 to 7% mixed with air in a proportion of around 93 to 95%.

[0012] It should also be noted that wet steam, such as the steam emitted by conventional steam cleaners, must be handled with great care, as there is a significant risk of burns for users.

[0013] The present invention aims to remedy, at least in part, the drawbacks of the devices known in the state of the art.

[0014] Thus, the present invention relates to a dry steam ejection device in the form of a tube intended to be connected, via a flexible pipe, to the tank of a steam cleaner, said steam ejection tube comprising a first end constituting the steam inlet in said tube and being intended to be connected to said flexible pipe via a mechanical tap and a second end constituting an outlet nozzle for said steam, said steam circulating, in said ejection tube, from said first end to said second end.

[0015] Said ejection tube according to the invention consists of a first hollow tubular element and a second hollow tubular element, arranged in the extension of one another and coaxial, each of said hollow tubular elements comprising an upstream end and a downstream end taking into account the direction of circulation of the steam in said ejection tube, said first hollow tubular element, the upstream end of which constitutes said first end of arrival of steam in said ejection tube, having an internal diameter of passage of the steam which is conical and decreasing from its upstream end towards its downstream end, which is abutted and fixedly secured to the upstream end of said second hollow tubular element whose internal diameter of passage of the steam is conical and decreasing from its upstream end towards its downstream end,the diameter of the downstream end of said first hollow tubular element opening partly into the diameter of the upstream end of said second hollow tubular element and being less than the latter.,

[0016] According to the invention, a chamber, in the form of an annular empty space without material, is provided on the external periphery of the downstream end of said first hollow tubular element opening into the diameter of the upstream end of said second hollow tubular element.

[0017] According to particular embodiments: said first hollow tubular element and said second hollow tubular element are fixedly secured by ultrasonic welding; the ratio between the diameter of the upstream end of said second hollow tubular element and the diameter of the downstream end of said first hollow tubular element is between 2 and 3.5; said ratio between the diameter of the upstream end of said second hollow tubular element and the diameter of the downstream end of said first hollow tubular element is of the order of, or equal to, 2.75; the conicity of said second hollow tubular element is greater than the conicity of said first hollow tubular element;the internal diameter of the steam passage of said first hollow tubular element decreases regularly from its upstream end to its downstream end with a ratio between the internal diameter D 43 of its upstream end and the internal diameter d 43 of its downstream end of between 1.25 and 1.5 while the internal diameter of the steam passage of said second hollow tubular element decreases regularly over at least part of its length from its upstream end to its downstream end with a ratio between the internal diameter D 53 of its upstream end and the internal diameter d 53 of its downstream end of between 2 and 4;on the downstream end of said second hollow tubular element, at the outlet of the ejection tube, the internal diameter of passage of the dry steam is straight over a portion of the length of said second element, said portion having a length corresponding to a proportion of between 8 and 11% of the total length of the second hollow tubular element; ;

[0018] The present invention also relates to a steam cleaner comprising in particular a tank incorporating a water reservoir as well as means for heating said water so that it is transformed into dry steam, as well as means for conveying this dry steam to a steam ejection device capable of allowing propulsion of said steam to a surface to be cleaned, said steam cleaner being characterized in that it is equipped with a dry steam ejection device as described previously.

[0019] Thus, in an inventive approach, it was imagined, for the manufacture of a steam ejection tube equipping a steam cleaner, to join two cones, each having a decreasing diameter, taking into account the direction of ejection of the steam, the first cone opening partly into the second, so as to create, within said steam ejection tube, a Venturi effect.

[0020] Obtaining this Venturi effect, within said steam ejection tube, in combination with the applied pressure, and heating the water vapor within the steam cleaner to a temperature above the boiling temperature, in particular above 110°C, or even above 140°C, makes it possible to accelerate the speed at the outlet of the ejection tube, so as to maintain the initial temperature for longer, and therefore to obtain superheated dry steam whose thermal energy is greater than a wet steam which is conventionally ejected from a steam cleaner.

[0021] As a reminder, dry steam does not contain any liquid molecules, only water molecules in the gaseous state, in a proportion of steam of the order of 5 to 7% mixed with air in a proportion of the order of 93 to 95%.

[0022] It should also be noted that the proportion of water vapor within the dry steam expelled from the ejection tube of the invention is extremely low, which results in reducing water consumption when using a steam cleaner equipped with an ejection tube according to the invention.

[0023] In other words, the creation of a Venturi effect within the steam ejection tube according to the invention, by the particular design of the latter, makes it possible to avoid heat losses during the transit of the superheated water vapor through said tube until its exit.

[0024] Thus, the temperature of the dry steam leaving the tube can be maintained above or equal to 120°C, sometimes in the order of 128-129°C, while the temperature of the (wet) steam expelled from conventional devices of the state of the art is generally between 70 and 90°C and condenses immediately on contact with the ambient air or a cold surface.

[0025] Among other advantages, such a temperature at the tube outlet, substantially higher than the existing one, allows for optimal disinfection efficiency against harmful microorganisms, effective dissolution of particularly stubborn residues, such as greasy residues, on all types of surfaces, without runoff of water droplets, and without requiring the use of chemical products, which is of significant interest from an environmental point of view.

[0026] Other aims and advantages of the present invention will appear during the description which follows relating to embodiments which are given only as indicative and non-limiting examples.

[0027] Understanding of this description will be facilitated by referring to the attached drawings in which: [ Fig.1 ] represents a schematic and sectional view of a first example of the dry steam ejection device which is not according to the invention, in the form of an ejection tube, formed by two upstream (or first tubular element) and downstream (or second tubular element) tubular elements, arranged in the extension of one another, taking into account the direction of circulation of the steam in said tube, this direction of circulation being symbolized by an arrow, each of said two tubular elements having a conical internal recess, the upstream ends of which have an internal diameter larger than the internal diameter of the downstream end; [ Fig.2 ] represents a schematic and sectional view of a first embodiment of the dry steam ejection device according to the invention, similar to the first example shown in the figure 1 , and furthermore having the particularity of comprising an empty annular space without material provided on the external periphery of the downstream end of the upstream tubular element, this end opening into the diameter of the upstream end of the downstream tubular element; [ Fig.3 ] represents a schematic and sectional view similar to the figure 2 , said empty annular space without material being highlighted. Fig.4 ] represents a schematic and sectional view of a second example which is not according to the invention in which, on the downstream end of the second hollow tubular element, at the level of the outlet of the ejection tube, the internal diameter of passage of the dry steam is straight over a portion of the length of said second tubular element.

[0028] In reference to the figures 1 à 4 of the attached drawings, a dry steam ejection device 1 in the form of a tube 2.

[0029] Said tube 2, referred to in the remainder of the description as the dry steam ejection tube 2, is intended to be connected, in particular by means of a flexible hose and a mechanical tap, to the tank of a household appliance of the steam cleaner type. The flexible hose, the tap, as well as the tank of the steam cleaner, are not shown in the attached figures.

[0030] Said dry steam ejection tube 2 comprises a first end 21, constituting the arrival of said dry steam in the tube 2. This first end 21 is intended to be connected, through suitable means known to those skilled in the art, to the tap mentioned above, itself connected to the tank of the steam cleaner by a flexible pipe, and which allows the steam to be conveyed from said tank to said ejection tube 2.

[0031] Opposite this first end 21, said ejection tube 2 comprises a second end 22, constituting an outlet for the dry steam outside the ejection tube 2, so that said steam can be directed effectively onto any surface to be cleaned or disinfected.

[0032] Thus, it is understood that the dry steam circulates, in the ejection tube, from the first end 21 of the latter towards the second end 22.

[0033] The direction of circulation of the dry steam in the ejection tube 2 according to the invention is symbolized, in the attached figures, by an arrow 3.

[0034] According to a particular feature specific to the steam ejection tube 2 of the invention, it is made up of at least a first hollow tubular element 4 and a second hollow tubular element 5

[0035] The first hollow tubular element 4 and the second hollow tubular element 5 are arranged in the extension of one another. Furthermore, said two hollow tubular elements 4, 5 are coaxial.

[0036] Said first hollow tubular element 4 comprises an upstream end 41 and a downstream end 42, taking into account the direction of circulation 3 of the dry steam in said ejection tube 2.

[0037] Likewise, the second hollow tubular element 5 comprises an upstream end 51 and a downstream end 52, again taking into account the direction of circulation 3 of the dry steam in said ejection tube 2.

[0038] Thus, it is clear from the above that the upstream end 41 of the first hollow tubular element 4 constitutes the first end 21 for the arrival of dry steam in the ejection tube 2, while the downstream end 52 of the second hollow tubular element 5 constitutes the outlet nozzle 22 for the dry steam outside the ejection tube 2.

[0039] In a particular and essential manner to the present invention, the two tubular elements 4 and 5, (first and second) arranged in the extension of one another and coaxial, each have a conical internal recess, referenced respectively 43 and 53 in the figures, the upstream ends 41, 51 of which have an internal diameter larger than the internal diameter of the downstream end 42, 52.

[0040] More specifically, said first hollow tubular element 4 of the ejection tube 2 has an internal diameter 43 for the passage of steam which is conical and decreasing from the upstream end 41 of said first hollow tubular element 4 towards the downstream end 42 thereof.

[0041] The downstream end 42 of said first hollow tubular element 4 is, for its part, abutted and fixedly secured, for example by means of ultrasonic welding, to the upstream end 51 of said second hollow tubular element 5.

[0042] Most preferably, the two hollow tubular elements 4, 5 are obtained by plastic injection and then welded together, in particular by ultrasound, in order to guarantee the position of said two elements 4, 5 and the sealing between the two.

[0043] Said second hollow tubular element 5 also has an internal diameter 53 for the passage of dry steam which is conical in shape and which decreases from the upstream end 51 of said second hollow tubular element 5 towards the downstream end 52 thereof.

[0044] However, most preferably, on the downstream end 52 of said second hollow tubular element 5, the internal diameter 53 for the passage of the dry steam is straight, in other words regular and constant, over the last 10 millimeters, in order to guarantee a powerful, straight and uniform jet of steam at the outlet 22 of the tube 2.

[0045] It should also be noted that, in a particularly advantageous manner, and as illustrated in the figures, the downstream end 42 of said first hollow tubular element 4 opens, in part, into the upstream end 51 of said second hollow tubular element 5, so that the diameter of the downstream end 42 of the first element 4 is less than the diameter of the upstream end of said second tubular element 5.

[0046] Such characteristics, specific to the ejection tube 2 of the invention, make it possible, in a particularly advantageous manner, to create a Venturi effect within said tube 2, in order to avoid losses, for maintaining the temperature of the dry steam at a particularly high temperature, greater than 120°C, until it leaves the tube 2.

[0047] Referring now to the figure 3 , according to a particularly interesting additional characteristic of the steam ejection tube 2 of the invention, a chamber, in the form of an annular empty space 6, without material, is provided at the level of the external periphery of the downstream end 42 of said first hollow tubular element 4.

[0048] More precisely, this annular empty space 6 surrounds the portion of the downstream end 42 of the first hollow tubular element 4 which opens into the conical internal recess 53 of said second hollow tubular element 5 which the ejection tube comprises, at the level of the upstream end 51 of this element 5.

[0049] The presence of such an annular empty space 6 devoid of material allows the creation of an air intake, for an air pump effect, which allows an optimization of the Venturi effect already created by the specific internal conformation of the steam ejection tube 2 according to the invention.

[0050] Most preferably, the ratio between the diameter D 53 of the conical internal recess 53 at the upstream end 51 of the second hollow tubular element 5 and the diameter d 43 of the conical internal recess 43 at the downstream end 42 of said first hollow tubular element 4, has a value between 2 and 3.5.

[0051] This ratio, between the “large” diameter D 53 of the upstream end 51 of said second element 5 and the “small” diameter d 43 of the downstream end 42 of said first element 4 is even more preferably of the order of 2.75.

[0052] Such ratio values ​​between the diameters D 53 / d 43 of the conical internal recesses 53, 43 of the second hollow tubular element 5 and of the first hollow tubular element 4, respectively, at the precise position where said conical internal recess 43 of the first tubular element 4 opens into the conical internal recess 53 of the second element 5, further allows optimization of the Venturi effect.

[0053] Advantageously, in the dry steam ejection tube 2 of the invention, the conicity of said second hollow tubular element 5 is greater than the conicity of said first hollow tubular element 4.

[0054] This means that the ratio between the largest diameter D 43 of the conical internal recess 43, at the upstream end 41 of the first tubular element 4, and the smallest diameter d 43 of said recess 43, is less than the ratio between the largest diameter D 53 of the conical internal recess 53, at the upstream end 51 of the second tubular element 5, and the smallest diameter d 53 of said recess 53.

[0055] Such a characteristic makes it possible to significantly increase the suction of the dry steam during its path within the conical recesses 43, 53 of the first and second hollow tubular elements 4, 5 of the ejection tube 2, and to further improve the Venturi effect already created by the specific internal shape of said tube 2 according to the invention.

[0056] Thus, most preferably the internal diameter 43 of the steam passage of said first hollow tubular element 4 decreases, in a regular manner, from its upstream end 41 towards its downstream end 42, with a ratio between the internal diameter D 43 of its upstream end 41 and the internal diameter d 43 of its downstream end 42 of between 1.25 and 2.5; preferably between 1.25 and 1.5 and even more preferably of the order of, or equal to, 1.4.

[0057] As regards, now, the internal diameter 53 of passage of the steam of said second hollow tubular element 5, this is decreasing, also in a regular manner over at least part of the length of said second element 5, from its upstream end 51 towards its downstream end 52, with a ratio between the internal diameter D 53 of its upstream end 51 and the internal diameter d 53 of its downstream end 52, having a value, this time, between 2 and 4, preferably between 2.8 and 3.2 and even more preferably a ratio of the order of, or equal to 2.9.

[0058] Indeed, as a reminder, according to a preferred characteristic of the tube of the invention, most preferably, on the downstream end 52 of said second hollow tubular element 5, in other words at the level of the outlet 22 of the ejection tube 2, the internal diameter 53 of passage of the dry steam is straight, in other words regular and constant, over a part 54 of the length of said second element 5.

[0059] More preferably still, the internal diameter 53 is straight over a portion 54 of a length I corresponding to a proportion of between 8 and 11% of the total length of the second hollow tubular element 5, in other words over a portion 54 having a length approximately equal to 10 millimeters.

[0060] Particularly advantageously, the internal diameter 53 at the level of the straight portion 54 of the second hollow tubular element 5 has a value of the order of, or equal to, 2 mm.

[0061] Such characteristics, illustrated on the figure 4 attached drawings, allow to guarantee a powerful, straight and uniform jet of steam at the level of the outlet 22 of the tube 2.

[0062] The invention also relates to a steam cleaner of the type conventionally known in the state of the art, comprising a tank with a water reservoir and means for heating the water so as to change it from the liquid state to the dry steam state, said steam cleaner further comprising means for conveying this water vapor from the reservoir to a device 1 for ejecting the steam to a surface to be cleaned.

[0063] Particularly in the steam cleaner according to the present invention, said steam ejection device 1 is in the form of a steam ejection tube 2 having the technical characteristics described previously in the description, in particular comprising two tubular elements, namely a first tubular element 4 and a second tubular element 5, arranged in the extension of one another, each having a conical internal recess 43, 53, the upstream ends 41, 51 of which have an internal diameter larger than the internal diameter of the downstream end 42, 52, while the downstream end 42 of the first tubular element 4 opens into the upstream end 51 of the second tubular element 5.

[0064] Obviously, the other additional characteristics which have been described in connection with the dry steam ejection device 1 alone can also be applied to the ejection device 1 intended to equip the steam cleaner of the invention.

Claims

1. Dry steam ejection device (1) in the form of a tube (2) intended to be connected, by means of a flexible hose, to the tank of a steam cleaner, said steam ejection tube (2) comprising a first end (21) constituting the steam inlet into said tube (2) and being intended to be connected to said flexible hose by means of a mechanical tap, and a second end (22) constituting an outlet nozzle for said steam, said steam circulating, in said ejection tube (2), from said first end (21) toward said second end (22), said ejection tube (2) is constituted by a first hollow tubular element (4) and a second hollow tubular element (5) arranged in the extension of each other and coaxially, each of said hollow tubular elements (4, 5) comprising an upstream end (41, 51) and a downstream end (42, 52) taking into account the direction of circulation (3) of the steam in said ejection tube (2), said first hollow tubular element (4), the upstream end (41) of which constitutes said first steam inlet end (21) in said ejection tube (2), having a conical internal steam passage diameter (43) decreasing from its upstream end (41) toward its downstream end (42), which abuts and is fixedly attached to the upstream end (51) of said second hollow tubular element (5), the internal steam passage diameter (53) of which is conical and decreases from its upstream end (51) toward its downstream end (52), the diameter of the downstream end (42) of said first hollow tubular element (4) opening in part into the diameter of the upstream end (51) of said second hollow tubular element (5) and being smaller than the latter, and a material-free annular empty space (6) is provided on the outer periphery of the downstream end (42) of said first hollow tubular element (4) opening into the diameter of the upstream end (51) of said second hollow tubular element (5).

2. Dry steam ejection device (1) according to claim 1, characterized in that said first hollow tubular element (4) and said second hollow tubular element (5) are fixedly attached by ultrasonic welding.

3. Dry steam ejection device (1) according to either claim 1 or claim 2, characterized in that the ratio between the diameter of the upstream end (51) of said second hollow tubular element (5) and the diameter of the downstream end (42) of said first hollow tubular element (4) is between 2 and 3.5.

4. Dry steam ejection device (1) according to claim 3, characterized in that said ratio between the diameter of the upstream end (51) of said second hollow tubular element (5) and the diameter of the downstream end (42) of said first hollow tubular element (4) is in the range of, or equal to, 2.75.

5. Dry steam ejection device (1) according to any of claims 1 to 4, characterized in that the conicity of said second hollow tubular element (5) is greater than the conicity of said first hollow tubular element (4).

6. Dry steam ejection device (1) according to claim 5, characterized in that the internal steam passage diameter (43) of said first hollow tubular element (4) decreases regularly from its upstream end (41) toward its downstream end (42), having a ratio between the internal diameter D43 of its upstream end (41) and the internal diameter d43 of its downstream end (42) of between 1.25 and 1.5, while the internal steam passage diameter (53) of said second hollow tubular element (5) decreases regularly over at least part of the length thereof from its upstream end (51) toward its downstream end (52), having a ratio between the internal diameter D53 of its upstream end (51) and the internal diameter d53 of its downstream end (52) of between 2 and 4.

7. Dry steam ejection device (1) according to claim 6, characterized in that, on the downstream end (52) of said second hollow tubular element (5), at the outlet (22) of the ejection tube (2), the internal dry steam passage diameter (53) is straight over a portion (54) of the length of said second element (5), said portion (54) having a length (I) corresponding to a proportion of between 8 and 11% of the total length of the second hollow tubular element (5).

8. Steam cleaner comprising in particular a tank incorporating a water reservoir as well as means for heating said water so that it is transformed into dry steam, as well as means for conveying this dry steam to a steam ejection device suitable for allowing said steam to be propelled onto a surface to be cleaned, said steam cleaner being characterized in that it is equipped with a dry steam ejection device (1) according to any of claims 1 to 7.