Apparatus for drying and / or washing laundry provided with an autonomous fire extinguishing device

Abstract

The invention relates to an apparatus for drying and / or washing laundry, the apparatus comprising: - an outer casing (12) having an opening (14) for loading the laundry; - a drum (16) located inside the casing (12) and being rotatably movable on an axis (A), said drum (16) having an inner cavity (18) connected to the loading opening (14) and being configured to receive the laundry; - a door (22) for closing the loading opening (14); and - at least one autonomous fire extinguishing device (30), said device (30) having at least one element made of a thermoplastic fusible material and an inner space (34) containing an extinguishing fluid intended to be released when the element melts under the effect of the heat generated by a fire or fire outbreak, characterised in that the extinguishing device (30) is located at least partially inside the cavity (18).

Description

[0001]

[0002] Technical field of the invention

[0003] The present invention relates to a laundry drying and / or washing appliance equipped with an autonomous fire extinguishing or fire outbreak device.

[0004] Technical background

[0005] Patent application FR-A1 -2 614 209 describes a fire-prevention device for electrical appliances containing flammable components, particularly for a washing machine or dryer.

[0006] A clothes dryer and / or washing machine is a household appliance that has a rotating drum in which laundry is placed to be washed with water and a cleaning agent, or wet laundry to be dried by agitation. The drum is generally rotated by a belt driven by an electric motor. A washing machine may have a dryer function. In both cases, the drum of the appliance may be crossed by a flow of hot air to facilitate the drying of the laundry during agitation. The heating and hot air flow generation system of the appliance may include a gas burner or an electric resistance, for example.

[0007] This household appliance is the cause of many domestic fires. Heating and mixing the laundry in the drum generates flammable dust that accumulates inside the appliance and is likely to ignite, particularly when it settles on very hot parts of the appliance such as the motor or the heating system. A fire caused by the ignition of the dust can cause a larger fire in the appliance, particularly by ignition of the drum drive belt. The patent application mentioned above proposes installing a reservoir in the form of a pressurized bomb in a washing machine, this reservoir being connected to normally closed pipes and likely to rupture at a given temperature threshold.These pipes extend to parts of the appliance that are subject to overheating or catching fire, such as electrical devices, resistors, the motor, flammable components, etc. The fire-fighting substance contained in the tank is at least slightly pressurized and the distribution pipes are made of a material intended to melt to ensure the rupture or opening of these pipes when they are licked by flames or when the temperature of their environment exceeds a predetermined threshold. In this way, as soon as conditions of overheating or flammability occur that could give rise to a fire inside the appliance, the pipes break and automatically distribute the fire-fighting substance to immediately extinguish the development of a possible fire.

[0008] The solution described in this patent application is not, however, entirely satisfactory because the fire extinguishing system formed by the tank and the pipes is complex and takes a long time to install in a household appliance.

[0009] The applicant's patent application FR-A1 -3 1 10 608 describes a laundry drying and / or washing appliance comprising a self-contained fire extinguishing device. This device is mounted in the casing and comprises a fusible thermoplastic pipe which is preformed and which contains an extinguishing fluid intended to be released by melting the pipe under the effect of the heat provided by a fire or the start of a fire. The particular shape imposed on the pipe allows it to be mounted in the casing and to pass through areas presenting a significant risk of fire spreading.

[0010] However, when a fire starts in the drum, it can be difficult to contain or extinguish with existing solutions. Solvent residues in clothing can accelerate the spread of the fire in the drum cavity, making it difficult to extinguish. Therefore, there is a need for a solution that can guarantee the extinction of a fire or fire as soon as it occurs inside the appliance drum.

[0011] Documents US-A1-213 / 139404 and EP-B1-2 360 310 propose that laundry stirring bosses be used in the drum as fire extinguishing devices. However, depending on the nature of the extinguishing material, the quantity of this extinguishing material contained in the stirring bosses is not always sufficient to extinguish a fire or fire outbreak in the drum. Furthermore, the release of the extinguishing material is not always automatic or sufficiently optimized since the outlets of the stirring bosses through which the extinguishing material can pass to extinguish flames are very localized and predetermined from the design of the stirring bosses.

[0012] The present invention provides a solution to at least some of the problems of the prior art, which is simple, effective and economical.

[0013] Summary of the invention

[0014] The invention provides a laundry drying and / or washing device, comprising:

[0015] - an external envelope of generally parallelepiped shape, this envelope comprising walls of which at least one has a laundry loading opening,

[0016] - a drum located in said casing and movable in rotation around an axis, this drum comprising an internal cavity connected to the loading mouth and configured to receive linen,

[0017] - a door for closing the loading mouth, this door being movable between positions for closing and opening said cavity, and

[0018] - at least one autonomous fire extinguishing device, this device comprising at least one element made, preferably entirely, of fusible thermoplastic material and an internal space containing an extinguishing fluid intended to be released by melting of the element under the effect of the heat provided by a fire or the start of a fire, characterized in that the extinguishing device is located at least partly in said cavity.

[0019] It is first important to note that the fluid, possibly under pressure, is stored directly in the device and that there is therefore no independent tank connected to this device.

[0020] One of the advantages of the extinguishing device is that it can be specially designed and have a specific shape for its integration into a clothes drying and / or washing machine. It can therefore have a very small footprint.

[0021] Another advantage of the device is that it is at least partly located directly in the laundry drying cavity and is therefore ideally located to extinguish a fire or a fire that starts in this cavity. Furthermore, if necessary, it would be possible to easily access the extinguishing device by opening the door. This access would be useful, for example, during maintenance or monitoring of the extinguishing device.

[0022] The apparatus according to the invention may comprise one or more of the following features, taken in isolation from one another or in combination with one another:

[0023] - the extinguishing device is carried by the drum;

[0024] - said element of the extinguishing device is a tubular ring or a portion of a tubular ring, which extends around said axis;

[0025] - the drum comprises an internal cylindrical surface and laundry stirring bosses which project from this internal cylindrical surface, at least one of these bosses forming said element;

[0026] - the bosses form independent extinguishing devices;

[0027] - the bosses are part of the same extinguishing device and include internal spaces which are connected to each other to form the same storage volume for the extinguishing fluid; - the bosses are connected to each other by connecting members ensuring the mechanical connection of the bosses between them, on the one hand, and the fluid communication of the internal spaces of the bosses, on the other hand;

[0028] - the bosses and the joining members form a single-piece unit;

[0029] - said single-piece assembly is made entirely of fusible thermoplastic material;

[0030] - the device comprises a number of bosses between 1 and 10, and preferably between 2 and 6;

[0031] - the extinguishing device is carried by the door;

[0032] - said element of the extinguishing device is in the form of a tubular ring or a portion of a tubular ring, which extends around said axis;

[0033] - said element forms a seal around the loading mouth or is located next to a seal around the loading mouth;

[0034] - the extinguishing device is carried by the casing;

[0035] - said element forms a seal around the loading mouth or is located next to a seal around the loading mouth;

[0036] - the door is or includes a porthole;

[0037] - the extinguishing device comprises a first part which is located in said cavity and a second part which is located outside the cavity and in the casing;

[0038] - the first part is located at the loading mouth and is in the form of a ring, a portion of a ring or a tubular loop;

[0039] - the first part forms a seal or is located next to a seal;

[0040] - the second part is fixed to one of the walls of the envelope;

[0041] -- the ring portion is closed at both ends; -- the device may be in the form of a single piece or several independent pieces or pieces connected to each other;

[0042] -- the or each extinguishing device is equipped with at least one sensor which is connected to a control device;

[0043] -- said control body is accessible by a user via, for example, a control panel of this device or any other means of exchanging information (for example Wifi, Bluetooth®, IR, etc.);

[0044] -- said control organ is a control organ of the device;

[0045] -- the sensor is a pressure, temperature or one or more other parameter(s) sensor;

[0046] -- said member can be configured to put the device into decommissioned mode when said sensor emits a particular signal; for example, said member is configured to put the device into decommissioned mode when said pressure sensor emits a signal corresponding to a pressure of said fluid lower than a predetermined threshold;

[0047] -- said organ is configured to emit a signal to a portable electronic device, such as a laptop or a mobile phone of the smartphone type for example;

[0048] -- said organ is configured to emit a signal to a computer network (for example home automation) or a computer database, such as a network or a database configured to ensure management of a fleet of several devices for the purpose of their maintenance;

[0049] -- said signal transmission is carried out wirelessly at a distance, for example by Wi-Fi, Bluetooth®, IR, etc.;

[0050] -- the device is monobloc;

[0051] -- the fluid is under pressure;

[0052] -- the fluid is at a pressure greater than 1 bar and less than or equal to 30 bars, preferably between 1 and 20 bars and for example between 1 and 10 bars; -- the fluid is in the liquid or gaseous state at room temperature (for example between 15 and 25°C);

[0053] -- the device includes a heating and hot air flow generation system located under the drum or on one side of the drum;

[0054] -- the device comprises a motor for driving the drum to rotate around its axis;

[0055] -- the drum includes microperforations for the passage of air and / or water.

[0056] Brief description of the figures

[0057] The invention will be better understood and other details, characteristics and advantages of the invention will appear more clearly on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

[0058] [Fig.1] Figure 1 is a schematic perspective view of a laundry drying and / or washing apparatus,

[0059] [Fig. 2] Figure 2 is a schematic perspective view of another laundry drying and / or washing apparatus,

[0060] [Fig. 3] Figure 3 is a schematic perspective view of another laundry drying and / or washing apparatus,

[0061] [Fig. 4] Figure 4 is a schematic perspective view of a drum of a laundry drying and / or washing appliance,

[0062] [Fig. 5] Figure 5 is a schematic perspective view of another drum of a laundry drying and / or washing appliance,

[0063] [Fig. 6] Figure 6 is a partial schematic perspective view of a laundry drying and / or washing appliance, the door of which is open,

[0064] [Fig. 7] Figure 7 is a very schematic view of a drum of a laundry drying and / or washing appliance, this drum comprising an extinguishing device according to a first embodiment of the invention,

[0065] [Fig. 8] Figure 8 is a partial schematic perspective view of a laundry drying and / or washing appliance, the drum of which comprises an extinguishing device according to a second embodiment of the invention, [Fig. 9] Figure 9 is a partial schematic perspective view of a laundry drying and / or washing appliance, the door of which comprises an extinguishing device according to a third embodiment of the invention, [Fig. 10] Figure 10 is a partial schematic perspective view of a laundry drying and / or washing appliance, the loading mouth of which comprises an extinguishing device according to a fourth embodiment of the invention, and

[0066] [Fig. 1 1] Figure 11 is a partial schematic perspective view of a laundry drying and / or washing appliance, the casing of which carries an extinguishing device according to a fifth embodiment of the invention.

[0067] Detailed description of the invention

[0068] Figure 1 schematically represents an appliance 10 for drying and / or washing laundry, such as a clothes dryer, that is to say a household appliance designed to dry laundry by stirring it and subjecting it to a flow of hot air. The appliance 10 may be intended for private or professional use.

[0069] The apparatus 10 comprises an external casing 12 of generally parallelepiped shape which comprises walls, for example a front wall 12a, a rear wall 12b, two opposite side walls 12c, an upper wall 12d and a lower wall 12e.

[0070] One of these walls 12a-12e comprises an opening 14 for loading laundry into the appliance 10. This opening 14 can be located on the front wall 12a as is the case in figures 1 and 2, or on the upper wall 12d as is the case in figure 3.

[0071] The appliance 10 further comprises a drum 16 located in the casing 12 and rotatable about an axis A. This axis A is generally oriented horizontally but could alternatively be inclined. In the case of a front-loading appliance 10 as illustrated in Figures 1 and 2, this axis A generally passes through the front 12a and rear 12b walls. In the case of a top-loading appliance 10 as illustrated in Figure 3, this axis A generally passes through the side walls 12c. The drum 16 comprises an internal cavity 18 connected to the loading mouth 14 and configured to receive laundry. The drum 16 defines any washing and / or drying volume and which is adapted to its use (private or professional).

[0072] The drum 16 is generally made mainly of sheet metal. It comprises a cylindrical wall 16a extending around the axis A and a circular wall 16b at one of its axial ends or at each of its axial ends.

[0073] The drum 16 of Figure 4 is intended to equip a front-loading device (Figures 1 and 2) and comprises a single circular wall 16b, at the rear of the cylindrical wall 16b. The front face of the drum 16 is therefore open and is located on the side of the loading mouth 14.

[0074] The drum 16 of Figure 5 is intended to equip a top-loading device 10 (Figure 3) and comprises two circular walls 16b located at the axial ends of the cylindrical wall 16a. The two faces of the drum 16 are therefore closed. These walls 16b or faces of the drum are intended to be located opposite the side walls 12c of the casing 12 and are therefore side walls or faces. The cylindrical wall 16a comprises a hatch 20 which communicates with the loading mouth 14. This hatch 20 must be located on the side of the upper wall 12d of the casing 12 to have access to the cavity 18 via the loading mouth 14.

[0075] The drum 16 may include microperforations for the passage of air and / or water during drying or spinning of the laundry, for example.

[0076] The apparatus 10 further comprises a door 22 for closing the loading mouth 14, this door 22 being movable between positions for closing and opening the cavity 18 (figure 6).

[0077] In the case of a front-loading appliance 10 (Figures 1, 2 and 6), the door 22 is movable about a vertical axis, this axis being located on one side of the door 22. In the case of a top-loading appliance 10 (Figure 3), the door 22 is movable about a horizontal axis, this axis being located at the rear of the door. The door 22 may comprise or be formed by a porthole (Figures 1 and 6) or be solid (Figures 2 and 3).

[0078] As is very schematically represented in Figure 1, a device 10 of this type further comprises:

[0079] - a motor 24 for driving the drum 16 in rotation around its axis A, which is located inside the casing 12; the motor 24 comprises an output shaft which drives the drum 16 in rotation by means of a belt for example,

[0080] - a system 26 for heating and generating a flow of hot air in the cavity 18 of the drum 16; the heating system 26 can be of any type and is for example of the heating resistance type, gas burner type, etc., and

[0081] - other elements 28 such as in particular an electronic control and command device for the various electrical equipment of the device, a capacitor or a hot air evacuation pipe laden with humidity, etc.

[0082] According to the invention, the apparatus 10 further comprises an autonomous device 30 for extinguishing fire or starting fire. This device 30 is advantageously located in the cavity 18 of the drum 16 and can be carried by the door 22, the drum 16 and / or the casing 12.

[0083] The device 30 comprises at least one element made of fusible thermoplastic material and comprising an internal space containing an extinguishing fluid intended to be released by melting of the element under the effect of the heat provided by a fire or the start of a fire.

[0084] Figures 7 to 11 illustrate several embodiments of an apparatus according to the invention.

[0085] In the first embodiment illustrated in Figure 7, the drum 16 is schematically represented by dotted lines. The cylindrical wall 16a of the drum 16 comprises an internal cylindrical surface 16a1.

[0086] In a known manner, the drum 16 comprises bosses 32 or laundry stirring blades, which project from the surface 16a1 (see figures 4 and 7). These bosses 32 are for example regularly distributed around the axis A. The number of these bosses 32 is between 1 and 10, and preferably between 2 and 6.

[0087] In the first embodiment illustrated in Figure 7, it is the drum 16 which carries the extinguishing device 30. More precisely, the bosses 32 of the drum 16 carry or form one or more extinguishing devices 30.

[0088] In the first configuration, the bosses 32 form independent extinguishing devices 30. That is to say, the bosses 32 each form one of the aforementioned elements and each comprise an internal space 34 containing extinguishing fluid. The internal spaces 34 of the elements and bosses 32 are independent of each other.

[0089] In the second configuration, the bosses 32 form a single extinguishing device 30. That is to say, the bosses 32 form elements which comprise internal spaces 34 containing extinguishing fluid. The internal spaces 34 of the elements and bosses 32 communicate with each other to form the same storage volume for the extinguishing fluid. For this, the bosses 32 can be connected to each other by connecting members 36 ensuring the mechanical connection of the bosses 32 between them, on the one hand, and also the fluid communication of the internal spaces 34 of the bosses 32, on the other hand. The bosses 32 and the connecting members 36 can form a single-piece assembly, that is to say an assembly formed from a single piece.

[0090] In the second embodiment illustrated in Figure 8, it is the drum 16 which carries the extinguishing device 30 which is in the form of a tubular ring or a portion of a tubular ring.

[0091] The ring or ring portion extends around the axis A and is located on the rear wall 16b of the drum 16 and for example on its periphery, at its junction with the cylindrical wall 16a. The ring or ring portion comprises an internal space for storing the extinguishing fluid, which preferably extends over the entire length of the ring or ring portion. In the third embodiment illustrated in Figure 9, it is the door 22 which carries the extinguishing device 30. The device 30 is preferably located on the face, here rear, of the door 22, which is located in the cavity 18 when the door 22 is closed.

[0092] The device 30 may also be in the form of a ring, ring portion or tubular loop for example. This element comprises an internal space for storing the extinguishing fluid, which preferably extends over the entire length of the ring or ring portion. The ring or ring portion may for example form a seal around the loading mouth 14 or be located next to a seal around the loading mouth 14.

[0093] In the fourth embodiment illustrated in Figure 10, the extinguishing device 30 is located at the loading mouth 14 of the apparatus 10. The device 30 can be carried by the drum 16, by the casing 12, or both.

[0094] In the fifth embodiment illustrated in Figure 11, the extinguishing device 30 is located partly at the loading mouth 14 of the apparatus 10 and partly outside the cavity 18 of the drum 16. In this case, the device 30 can be carried by the drum 16, by the casing 12, or both.

[0095] The device 30 thus comprises a first part 30a which is located in the cavity 18, at the level of the loading mouth 14, and a second part 30b which is located outside the cavity 18 and in the casing 12.

[0096] The first part 30a of the device 30 may be in the form of a ring, a portion of a ring or a tubular loop for example. This element comprises an internal space for storing the extinguishing fluid, which preferably extends over the entire length of the ring or portion of the ring.

[0097] The first part 30a may for example form a seal around the loading mouth 14 or be located next to a seal around the loading mouth 14. The second part 30b may extend into the casing 12, as described in the prior application FR-A1-3 1 10 608, and be fixed by appropriate means to one of the walls, here lateral 12c, of the casing 12.

[0098] In the various embodiments described above, the device 30 is advantageously equipped with a valve 38 for filling its internal space with extinguishing fluid, as described in application FR-A1-3 088 215 (see figure 7).

[0099] The device 30 can be equipped with a pressure sensor 40 which is configured to measure the pressure of the fluid 29 and which is connected to a control and command member 42 of the apparatus 10 (see figures 1 and 7).

[0100] This member 42 is configured to put the device 10 into decommissioned mode when the pressure sensor 40 emits a signal corresponding to a fluid pressure lower than a predetermined threshold. The member 42 can further be configured to emit a signal to a portable electronic device such as a smartphone-type mobile phone, in order to warn the user or owner of the device in the event of a malfunction of the latter.

[0101] Alternatively, the device 30 could be equipped with a sensor for measuring parameters other than pressure, such as temperature for example.

[0102] The wall of the element or device 30 may be of the single-layer or multi-layer type. It may, for example, comprise two layers, respectively internal and external.

[0103] The inner layer may be made of a material with low permeability relative to the extinguishing fluid 29, i.e. with a permeability less than or equal to 1 cm 3 .25pm / m 2 .atm.24h. For example, it is made of fluorinated thermoplastic material or EVOH.

[0104] The outer layer is made of a thermoplastic polyamide material, which generally has a permeability greater than that of the inner layer, for example greater than or equal to 1 cm 3 .25pm / m 2 .atm.24h.

[0105] It is preferable for the low permeability layer to be located inside the higher permeability layer. Otherwise, there would be a risk of gas migrating through the higher permeability inner layer and stagnating at the interface between the two layers, which could lead to delamination of the layers.

[0106] It is also advantageous to make the element or device in two layers rather than a single layer of low-permeability material because this material is relatively expensive. To have sufficient resistance, particularly under pressure, a single-layer element should have a significant thickness of low-permeability layer. In the case of a two-layer or multi-layer element, this resistance is ensured by the layer(s) with the highest permeability, and the low-permeability layer may have a relatively small thickness sufficient to ensure the desired impermeability function.

[0107] In another variant not shown, the low permeability layer could be arranged between two layers. This configuration would improve the mechanical strength of the layer during the element shaping stage (and thus avoid any risk of tearing of this layer), while ensuring optimal sealing of the element.

[0108] Among the wall materials, at least one has a fusible property under the effect of heat generated by a fire or the start of a fire, and in particular under the effect of a temperature greater than or equal to 70°C, or even 120°C.

[0109] In the example described above, both layers have such a fusible property.

[0110] In a particular embodiment of the invention, the ring or ring portion of the element has an external diameter of between 10 and 30mm, and preferably between 10 and 20mm. The wall has a thickness of between 1 and 3mm, and preferably between 1 and 2mm.

[0111] The extinguishing fluid can be stored in the aforementioned space at a pressure greater than 1 bar and which can reach 10 bars, 20 bars or even 30 bars.

[0112] The extinguishing fluid preferably does not include HFC gas of the R236Fa type because this gas has a very high GWP or GWP of around 9400. The extinguishing fluid preferably has a GWP or GWP of less than or equal to 5000. The fluid may include at least one HFC gas and / or C6F12O, and / or CO2. Among the HFC gases that can be used, R227ea and R125 gases are preferred because they have a GWP or GWP of around 3400-3500. The DuPont® company, for example, markets gases of this type under the names FE-25 and FM-200.

[0113] CO2 is advantageous because it has a GWP or PRG of 1.

[0114] Finally, C6F12O is also advantageous because it has a GWP or PRG of 1. The 3M company in particular markets this type of gas under the name Novec® 1230 (FK-5-1 -12).

Claims

DEMANDS 1. Laundry drying and / or washing appliance (10), comprising: - an outer casing (12) of general parallelepiped shape, this casing (12) comprising walls (12a-12e) at least one of which has a laundry loading opening (14), - a drum (16) located in said casing (12) and movable in rotation about an axis (A), this drum (16) comprising an internal cavity (18) connected to the loading opening (14) and configured to receive laundry, - a door (22) for closing the loading opening (14), this door (22) being movable between closed and open positions of said cavity (18), and - at least one autonomous fire extinguishing device (30), this device (30) comprising at least one element made entirely of fusible thermoplastic material and an internal space (34) containing an extinguishing fluid intended to be released by melting of the element under the effect of the heat supplied by a fire or start of fire, characterized in that the extinguishing device (30) is located at least partly in said cavity (18).

2. Apparatus (10) according to claim 1, in which the extinguishing device (30) is carried by the drum (16).

3. Apparatus (10) according to claim 2, wherein said element of the extinguishing device (30) is a tubular ring or a portion of a tubular ring, which extends around said axis (A).

4. Apparatus (10) according to claim 2, wherein the drum (16) comprises an internal cylindrical surface (16a1) and laundry stirring bosses (32) which project from this internal cylindrical surface (16a1), at least one of these bosses (32) forming said element.

5. Apparatus (10) according to claim 4, in which the bosses (32) form independent extinguishing devices (30).

6. Apparatus (10) according to claim 4, in the bosses (32) are part of the same extinguishing device (30) and include internal spaces (34) which are connected to each other to form the same storage volume for the extinguishing fluid.

7. Apparatus (10) according to claim 6, in which the bosses (32) are connected to each other by connecting members (36) ensuring the mechanical connection of the bosses (32) to each other, on the one hand, and the fluidic communication of the internal spaces (34) of the bosses, on the other hand.

8. Apparatus (10) according to claim 7, in which the bosses (32) and the connecting members (36) form a single-piece assembly.

9. Apparatus (10) according to claim 8, wherein said one-piece assembly is entirely made of fusible thermoplastic material.

10. Apparatus (10) according to any one of claims 4 to 9, wherein it comprises a number of bosses (32) between 1 and 10, and preferably between 2 and 6.

11. Apparatus (10) according to claim 1, in which the extinguishing device (30) is carried by the door (22).

12. Apparatus (10) according to claim 1 1 , in which said element of the extinguishing device (30) is in the form of a tubular ring or a portion of a tubular ring, which extends around said axis (A).

13. Apparatus (10) according to claim 12, wherein said element forms a sealing gasket around the loading mouth (14) or is located next to a sealing gasket around the loading mouth (14).

14. Device (10) according to claim 1, in which the extinguishing device (30) is carried by the casing (12).

15. Apparatus (10) according to claim 14, wherein said element forms a sealing gasket around the loading mouth (14) or is located next to a sealing gasket around the loading mouth (14).

16. Apparatus (10) according to any one of the preceding claims, wherein the door (22) is or includes a porthole.

17. Apparatus (10) according to any one of the preceding claims, wherein the extinguishing device (30) comprises a first part (30a) located in said cavity (18) and a second part (30b) located outside the cavity (18) and in the casing (12).

18. Apparatus (10) according to claim 17, wherein the first part (30a) is located at the loading opening (14) and is in the form of a ring, a portion of a ring, or a tubular loop.

19. Apparatus (10) according to claim 17 or 18, wherein the first part (30a) forms a sealing joint or is located next to a sealing joint.

20. Apparatus (10) according to any one of claims 17 to 19 wherein the second part (30b) is fixed to one of the walls of the envelope (12).

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