EP0682137B1 - Rotary cylinder ironer with an improved gas heating ramp - Google Patents

Description

The invention relates to a dryer-ironer with rotating cylinder, in which the cylinder heating is carried out by means of a gas heating ramp placed inside the latter.

The dryer-ironer according to the invention can be used in all areas of traditional use of such a machine, that is to say in particular in communities involving the ironing of large quantities linen (hospitals, boarding schools, hotels, restaurants, etc.).

As illustrated in particular by the document FR-A-2 479 789, a dryer-ironer with rotating cylinder is a machine in which the ironing linen is inserted from above, at the front of the machine, between the rotating cylinder and a mat or set of bands unending. A source of gas, steam or electric is placed inside the cylinder for help dry and iron clothes. Once dried and ironed, the latter comes out from the bottom, forward machine, to be collected in bulk in a bin receiving front or folded by a suitable device.

In the particular case where heating is provided by a gas heating rail, this is usually constituted by a tube, of circular section, in which one injects the air-gas mixture by one end. This mixture leaves the ramp through a row of calibrated holes formed according to a generator of the tube, to be ignited by an ignition system placed outside the tube. The document US-A-5,054,543 describes a dryer-ironer cylinder, the heating of which is carried out using such a ramp.

Gas heating ramps traditionally used form flames (usually blue) outside the ramp.

Rotating ironer dryers using gas heaters have a a number of drawbacks, which arise in particular from the formation of flames outside the ramp.

First, the flames produced by the existing gas heating ramps tend to take off, which requires the addition on the latter an annex ramp provided with a second row of perforations calibrated opening at right angles to the first row of perforations.

In addition, the flames formed outside of the ramp can hardly be tilted by compared to the vertical. Therefore, effective scanning of the inner surface of the rotating cylinder cannot be assured. The thermal efficiency of dryer-ironers whose cylinder is heated by such ramps is therefore mediocre.

In addition, the distribution of gas inside a traditional design gas heating rail takes place irregularly, which contributes to creating a thermal gradient along the cylinder. This can lead to overheating of the laundry in some dryer-ironer areas. To remedy this difficulty, we often have to place it inside of the same cylinder rotating two heating ramps at gas in parallel, closing the holes in one of them in areas of overheating.

The different arrangements usually offered in order to overcome the drawbacks of the heating ramps to existing gases lead to make this technique relatively expensive.

In addition, the design of the heating ramps gas traditionally used in dryer-ironers with rotating cylinder do not allow use them with all types of existing gas.

In document US-A-3 488 137, it is proposed a gas burner which includes a hot plate perforated, in a refractory material, and a mesh metal placed 0.5 mm above the plate refractory. The combustion of the gas takes place above the roasting and produces flat flames. The surface lower of these heats the grill to a high temperature, so that it radiates infrared rays.

The subject of the invention is precisely a rotary ironer-dryer fitted with a improved gas heating rail, the original design eliminates the disadvantages of existing ramps by making the flames disappear the outside of the ramp, which allows in particular to tilt and avoid detachment without it necessary to add a second ramp or additional accessories.

According to the invention, this result is obtained by means of a cylinder dryer-ironer rotating and gas heated including, inside of the cylinder, a gas heating rail, means supplying this ramp with an air-gas mixture, connected to one end of the ramp, holes calibrated formed in the ramp, to allow passage air-gas mixture, and gas ignition means coming out of the calibrated holes, characterized in that the calibrated holes consist of a dense network micro-perforations ensuring gas combustion mainly inside the micro-perforations and heating mainly in the infrared and by the causes the gas heater to be placed in infrared and by the fact that the heating ramp gas is placed in a lower region of the rotating cylinder, axes of micro-perforations being inclined with respect to the vertical, so that be oriented externally towards part of the cylinder near a laundry outlet area, and at against direction relative to the direction of rotation of the cylinder.

The combustion of the gas taking place inside micro-perforations, any detachment problem flames is avoided and it becomes possible to tilt these perforations in order to increase the yield machine thermal.

In addition, the production of infrared at the inside of the rotating cylinder provides heating efficient and more uniform of the latter, by convection, whatever the nature of the gas used and without the need to use gas under pressure.

The localization of the flames inside the micro-perforations and the production of infrared are ensured both by the considerable increase in the number of calibrated holes per unit area and by the significant reduction in their section, compared to the ramps. gas heaters commonly used in ironer dryers. Thus, and only by way of example, the density of the micro-perforations according to the invention can be approximately 400 per cm ² , for a section of 1180 cm ² and a length of 1600 mm.

Use of a gas heater according to the invention therefore allows both to increase machine performance and reduce the cost of manufacturing.

A product recovery ramp of combustion is advantageously placed in a region upper of the rotating cylinder, near an area of the linen, so as to sweep by the combustion products a useful part of the cylinder located between the zones of introduction and exit of the linen.

In order to improve the regularity of the heating the along the ramp, it is advantageously equipped at least one perforated distribution plate cutting out internally the ramp, lengthwise, in at least two areas.

In a first embodiment of the invention, the supply means then open completely in a first of said zones, adjacent to the end of the ramp, to which these feeding means. The distribution plate (s) ensuring a substantially uniform distribution of the mixture air-gas along the ramp.

In a second embodiment of the invention, the feeding means open into each zones and include distribution means ensuring controlled feeding of each zone in mixture air-gas. This feature allows, depending on the width of the linen ironed, adjust the heating distribution on along the ramp and, therefore, of the rotating cylinder.

In this second embodiment of the invention, adjustment accuracy can be further improved by providing means for moving each distribution plate along the axis of the ramp.

In practice, micro-perforations can in particular be formed in material plates ceramic.

In this case, the ramp advantageously comprises a tubular metal part having a substantially face plane, parallel to its axis, in which are formed of juxtaposed windows, the plates of material ceramic being mounted in these windows by waterproof fixing means.

These sealed fastening means can in particular include tabs formed in the metal part tubular and folded down on the material plates ceramic, and flexible sealing pads, interposed between these plates and the window frames.

• la figure 1 est une vue en coupe transversale illustrant de façon très schématique le principe de fonctionnement d'une sécheuse-repasseuse à cylindre tournant et à chauffage au gaz conforme à l'invention ;
• la figure 2 est une vue de côté représentant plus en détail la rampe de chauffage au gaz équipant la sécheuse-repasseuse de la figure 1, selon une première forme de réalisation de l'invention ;
• la figure 3 est une vue à plus grande échelle représentant, en coupe longitudinale partielle, l'extrémité de la rampe de la figure 2 par laquelle s'effectue l'alimentation en mélange air-gaz ;
• la figure 4 est une vue en coupe selon la ligne IV-IV de la figure 3, et
• la figure 5 est une vue comparable à la figure 2 illustrant une deuxième forme de réalisation de l'invention.

Two preferred embodiments of the invention will now be described, by way of non-limiting examples, with reference to the appended drawings, in which:

• Figure 1 is a cross-sectional view illustrating very schematically the operating principle of a dryer-ironer with rotating cylinder and gas heating according to the invention;
• Figure 2 is a side view showing in more detail the gas heating rail fitted to the dryer-ironer of Figure 1, according to a first embodiment of the invention;
• Figure 3 is an enlarged view showing, in partial longitudinal section, the end of the ramp of Figure 2 through which the air-gas mixture is supplied;
• FIG. 4 is a sectional view along the line IV-IV of FIG. 3, and
• Figure 5 is a view comparable to Figure 2 illustrating a second embodiment of the invention.

As Figure 1 very schematically illustrates, the invention relates to a dryer-ironer comprising a rotating cylinder 10, of horizontal axis, suitable for being rotated around this axis, in the direction of arrows F1, by conventional drive means (not shown) which are not part of the invention.

The dryer-ironer illustrated very schematically in Figure 1 further includes a carpet or endless bands 12 which run on rollers 14 of which the axes are parallel to the horizontal axis of the cylinder 10. These rollers 14 are arranged so that the carpet or the endless belts 12 are in contact with the cylinder rotating 10 substantially over half of its circumference. More specifically, the carpet or the strips endless 12 are in contact with the part of the circumference of cylinder 10 which moves in the downward direction when the cylinder turns in the direction of the arrows F1 in Figure 1.

In a dryer ironer of this type, the laundry to be ironed is introduced into an introduction zone of the laundry located in the upper region of the rotating cylinder 10. To facilitate its entry between the rotating cylinder 10 and the endless belt or belts 12, the laundry is placed on an introduction system such as a horizontal shelf 16 located near the cylinder 10, in the laundry introduction area. Linen introduced between cylinder 10 and endless belt or belts 12 is driven by these, so as to be dried and ironed, especially under the effect of heating the cylinder turning 10. The dried and ironed laundry comes out of the machine in a laundry outlet area located in the region bottom of the rotating cylinder 10. It can in particular be collected in this area by a bin (not shown) provided for this purpose below the cylinder 10.

The rotating cylinder 10 is a hollow cylinder in which is received a gas heating ramp 18 produced according to the invention. This ramp 18 is fixed and extends parallel to the horizontal axis of the rotating cylinder 10 and over most of its length. She is placed in a lower region of the cylinder, that is to say near the laundry outlet area.

A ramp 20 for the recovery of combustion is also placed inside the cylinder turning 10. This ramp 20 is fixed and also extends parallel to the horizontal axis of the rotating cylinder 10 over most of its length. She is placed in an upper region of the rotating cylinder 10, above the gas heating ramp 18, that is to say near the zone of introduction of the laundry.

We will now describe in detail, referring to Figures 2 to 4, a first embodiment of the gas heating ramp 18.

The gas heating ramp 18 comprises a room tubular metal 22 which has a uniform section over its entire length. This section, which is triangular in the example shown, can take many other forms without departing from the scope of the invention.

The left end of the tubular metal part 22, considering FIG. 1, is closed while the opposite end communicates with supply means 24 of the ramp 18 in air-gas mixture.

The supply means 24, of the ramp 18 in air-gas mixture, include a line 26 for the arrival of gas, suitable for connection to a gas source (not shown) by any appropriate means. Line 26 of arrival gas is fitted with a valve 28, for example of the type all or nothing. Valve 28 can be replaced by a tap allowing to modulate the gas flow admitted in the gas heating ramp 18 or in certain areas of this ramp, as we will see later.

The supply means 24 of the ramp 18 in air-gas mixture additionally include a compression 30 into which the pipe 26 opens. This compression chamber 30 is equipped with one or more injectors 32 on a flat face facing the end adjacent to the tubular metal part 22 of the ramp 18. The dimensions of these injectors 32, which depend on the gas used, are low enough to that there is still pressure in the gas compression 30 when the valve 28 is open. In the embodiment illustrated in Figures 2 to 4, the compression chamber 30 is equipped with three injectors 32 arranged at the top of an equilateral triangle having a horizontal bottom side.

The compression chamber 30 is placed inside an air-gas mixing chamber 34, in which open the injectors 32. The wall of the chamber 34 of air-gas mixture facing the tubular metal part 22 supports as many venturi tubes 36 as there are injectors 32. Each of the venturi tubes 36 is aligned with one of the injectors 32 and opens out inside the tubular metal part 22 of the ramp 18, as this is illustrated in particular in Figure 3.

Specifically, the entry end of each venturi tubes 36 is tightly attached to the above-mentioned wall of the air-gas mixing chamber 34 and each of the venturi tubes 36 passes through tightly a wall 37 closing the adjacent end of the part tubular metal 22.

The opposite wall of the air-gas mixing chamber 34 to that which supports the venturi tubes 36 comprises perforations 38 through which the surrounding air is admitted in room 34. An air filter 40 is placed in this room, behind the perforations 38, in order to retain any particles present in the air. After passing through this filter 40, the air admitted into the mixing chamber 34 is mixed with the gas leaving the injectors 32 in the space separating these injectors from the inlet end of the venturi tubes 36.

In the embodiment illustrated on the Figures 2 and 3, the venturi tubes 36 all open at same level in the tubular metal part 22, in one relatively close to the wall 37.

A perforated distribution plate 42 is placed transversely inside the metal part tubular 22, slightly beyond the outlet ends venturi tubes 36. This distribution plate 42, possibly in association with one or more others perforated distribution plates such as plate 43 in Figure 2, internally cut the ramp 18 into one number of zones A, B and C. Distribution plates 42, 43 establish predetermined pressure drops between these zones A, B and C, ensuring a relatively uniform distribution of the air-gas mixture over the entire length of the gas heating ramp 18.

As illustrated more specifically in Figure 4, the tubular metal part 22 has a face 44 substantially flat, oriented parallel to its longitudinal axis, with an inclination of about 60 ° from the vertical. This face 44 comprises, on the major part of its length, windows 46, rectangular or all other forms, juxtaposed. On each of these windows 46 is tightly fixed a plate rectangular 48 in ceramic material the dimensions of which are slightly higher than those of windows 46, so as to completely cover these.

Each of the plates 48 of ceramic material is crossed in the direction of its thickness by a network dense of micro-perforations 49, through which the air-gas mixture admitted into the gas heating rail 18 by the supply means 24.

The fixing of the plates 48 of ceramic material on the tubular metal part 22 is provided by waterproof fixing means. In the embodiment illustrated in FIG. 4, these fixing means watertight include tabs 50, for example formed by stamping in the tubular metal part 22 and folded down on the plates 48, so as to maintain them pressed against the flat surface 44. The tightness of fixing is ensured by sealing pads flexible 52, which are interposed between the peripheral edge of each of the plates 48 and the frame 54 of the window 46 corresponding. These sealing pads 52 allow in particular to preserve the seal between each of the pads 48 and its frame 54 despite expansions differentials that occur between the wafer and the tubular metal part 22.

In order to ignite the gas leaving the gas heating rail 18 by micro-perforations 49 formed in the pads 48, the surface 44 of the part tubular metal 22 also supports, near the end of this room adjoining the supply means 24, means 56 for igniting the gas passing through the micro-perforations. These ignition means 56 include for example, in known manner, an ignition system by train of sparks as well as a control system flame by ionization.

It should be noted that the distribution substantially uniform air-gas mixture over the entire length of the ramp 18 provided by distribution plates 42 and 43 allows ignition of the gas at one end of the ramp. This allows you to place all of the pipes and electrical conductors at one end of the ramp 18, which facilitates its assembly and disassembly.

The density of the micro-perforations 49 formed in the plates 48 as well as their very reduced section allow, after ignition of the gas by the ignition means 56, to form micro-flames inside the same micro-perforations 49 formed in the plates. We thus performs heating in the infrared range.

This characteristic makes it possible in particular to orient micro-flames to the inner surface of the cylinder turning 10, near the laundry outlet area, as illustrated in figure 1. More precisely, the inclination micro-perforations 49 substantially at 60 ° by vertical relationship combined with the mounting of the ramp 18 in the lower region of the rotating cylinder and, with the orientation of face 44 towards the part of the cylinder which moves down during its rotation (figure 1), allows to establish a circulation of products combustion along the inner surface of the cylinder 10, against the direction of the latter's rotation, as illustrated by the arrows F2 in FIG. 1. These combustion products are taken up by ramp 20 of recovery of combustion products, after they have internally swept most of the cylinder around from which the ironing linen circulates. An efficiency optimal thermal performance of the machine is thus ensured.

Furthermore, it should be noted that the structure of the gas heating rail 18 according to the invention can be obtained at lower cost. This also constitutes a appreciable advantage over machines of art prior.

In a second embodiment of the invention illustrated by FIG. 5, the heating ramp 18 with gas has slightly different characteristics of those which have been described with reference to Figures 2 to 4, to allow adjustment of the distribution of heating along the ramp as a function the type of laundry you want to dry and iron.

In this case, the tubular metal part 22 is split lengthwise into n separate zones (e.g. 3) by perforated distribution plates 42, 43, as in the first embodiment described. So, for example, we find inside the tubular metal part 22 an entry zone A, a central zone B and a terminal zone C. However, at all lead to entry zone A, each of venturi tubes opens into a different area. So, we have identified by 36a the venturi tube opening into the inlet zone A, through 36b the venturi tube emerging in the central zone B and by 36c the venturi tube opening into terminal zone C.

The inlet end of each of the venturi tubes 36a, 36b and 36c is then in front of an injector 32a, 32b and 32c communicating with a separate compression 30a, 30b and 30c respectively. These three compression chambers are placed in one chamber single air-gas mixture 34.

In this case, the gas supply to each of the compression chamber 30a, 30b and 30c is provided by a separate line fitted with a metering tap. Only the line 26b supplying gas to the compression chamber 30b, and the valve 28b placed in this line are shown in Figure 5. It is thus possible to supply at will in gas, according to a controlled flow, each zones A, B and C, to take into account the dimensions of the ironing linen.

According to an improvement to the embodiment illustrated in figure 5, the distribution plates perforated 42 and 43 are mounted in the metal part tubular 22 so that it can move parallel to the longitudinal axis thereof. The means provided for in this effect may be constituted by any mechanism allowing to make a final adjustment upon delivery of the machine, or a setting accessible to the user either from outside the machine or by dismantling the gas heating rail.

Of course, the invention is not limited to embodiments which have just been described under example, but covers all variants. In particular, the dense network of micro-perforations ensuring the combustion of the gas in the infrared according to the invention can be obtained either by using platelets different natures than the material pads ceramic used in both embodiments described, either by forming the micro-perforations directly in the material constituting the tubular part forming the ramp. Furthermore, if the injection of air-gas mixture is entirely done in the entry area of the boom, a single injector-venturi tube assembly can be used.

Throughout the text, the term “plate” means solid object with perforation or any object obtained by weaving or compression or any other means of assembling fibers or particles having a porosity allowing the optimum passage of the air-gas mixture.

Claims (9)

1. Drying and ironing machine having a rotary cylinder (10) and gas heating comprising, within the cylinder, a pipe burner (18), means (24) for supplying said pipe burner with an air-gas mixture, connected to one end of the pipe burner, calibrated holes formed in the pipe burner to permit the passage of the air-gas mixture, and means (56) for igniting the gas passing out of the calibrated holes, characterized in that the calibrated holes are constituted by a dense network of microperforations (49) ensuring a combustion of the gas mainly within the microperforations and heating mainly in the infrared and in that the pipe burner (18) is placed in a lower region of the rotary cylinder (10), the axes of the microperforations (49) being inclined with respect to the vertical, so as to be externally oriented towards a part of the cylinder close to a linen exit zone and in the opposite direction to the rotation direction of the cylinder.
2. Drying and ironing machine according to claim 1, characterized in that microperforations (49) are formed in the ceramic material plates (48).
3. Drying and ironing machine according to claim 2, characterized in that the pipe (18) comprises a tubular metal part (22) having a substantially planar face (44) parallel to its axis and in which are formed juxtaposed windows (46), the ceramic material plates (48) being installed in these windows by tight fixing means (50, 52).
4. Drying and ironing machine according to claim 3, characterized in that the tight fixing means comprise tongues (50) formed in the tubular metal part (22) and lowered onto the ceramic material plates (48), as well as flexible sealing pads (52) interposed between said plates and the frames (54) of said windows (46).
5. Drying and ironing machine according to any one of the preceding claims, characterized in that it also comprises a combustion product recovery pipe (20) placed in an upper region of the rotary cylinder (10), in the vicinity of a linen introduction zone, so as to ensure that the combustion products sweep a useful part of the cylinder located between the introduction and discharge zones for the linen.
6. Drying and ironing machine according to any one of the preceding claims, characterized in that the pipe burner (18) is equipped with at least one perforated distribution plate (42, 43) internally subdividing the pipe in the lengthwise direction thereof into at least two zones (A, B, C).
7. Drying and ironing machine according to claim 6, characterized in that the supply means (24) issue entirely into a first of said zones adjacent to said end of the pipe, the distribution plate (42, 43) ensuring a substantially uniform distribution of the air-gas mixture along the pipe (18).
8. Drying and ironing machine according to claim 6, characterized in that the supply means (24) issue into each of the zones (A, B, C) and have distribution means (28b) ensuring a controlled supply of each zone with the air-gas mixture.
9. Drying and ironing machine according to claim 8, characterized in that means are provided for the displacement of each distribution plate (42, 43) along the axis of the pipe burner (18).

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