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The present invention relates to an apparatus for filtering air in tunnels.
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For example, the present invention may be applied for filtering air in road, rail or other tunnels while under construction or while maintenance work is carried out on them.
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In both cases vehicles equipped with machining tools may be used, such as a cutter mounted on a mobile arm, which dig rocky terrain to create the tunnel or demolish a tunnel concrete vault which must be rebuilt.
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In any case, this type of machining generates a large amount of dusts which spread through the machining zone or the entire tunnel.
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In particular with reference to an open tunnel, for example in the case of maintenance work on an existing tunnel, the dust produced by the action of a cutter may easily be drawn by an air flow which may be established inside the tunnel.
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In this way, the dusts may spread through zones where specialised personnel are present.
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For this reason, a special barrier must be set up downstream (with reference to the air flow) of the position where the work is carried out. The barrier transversally blocks the tunnel to delimit the working zone. Therefore, the air in this zone may be suitably filtered.
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The closing barriers commonly used comprise a supporting structure and one or more sheets or panels suitably fixed to the supporting structure to close the tunnel.
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An intake duct draws an air flow from the zone delimited by the barrier and directs it towards a known type of filter apparatus. In particular, the duct accesses the zone through a hole or opening made in the barrier itself.
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The known type of filtering apparatus comprises a frame on which an air treatment unit is positioned, comprising a plurality of filters which separate solid particulate matter from the air flow, conveying the dusts into a hopper below the filters.
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The treatment unit comprises an intake inlet connected to the duct coming from the zone delimited by the barrier and a delivery outlet through which a flow of filtered air comes out, direct in a downstream direction relative to the apparatus.
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The air flow is generated by a fan positioned on the frame and connected to the treatment unit.
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The frame is mobile and can easily move along the tunnel as work progresses. For that purpose, it is slidably mounted on two longitudinal members on which it can be made to slide with the aid of site machines normally present there.
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Once the work has been completed in a certain zone of the tunnel, the site must be moved and in the same way the filtering apparatus and the barrier needed to delimit the zone from which the air will be extracted must also be moved.
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Disadvantageously, moving the prior art apparatuses and closing barriers is a laborious operation which requires significant periods of time, as well as a large number of personnel present to carry out that operation.
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To move the barrier, the intake duct must be moved away from the barrier, then the covering sheets or panels must be removed from the supporting structure. Finally, the supporting structure must also be disassembled.
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Once those steps have been completed, the barrier can be set up in a subsequent position. Obviously, the new set-up operation for the barrier and the filtering apparatus requires considerable time and manpower.
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Consequently, as regards existing tunnels, with the prior art equipment the entire tunnel must be closed to traffic for the duration of the work.
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In this context, the technical purpose which forms the basis of the present invention is to provide an apparatus for filtering air in tunnels which overcomes the above-mentioned disadvantages of the prior art.
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In particular, the present invention has for an aim to provide an apparatus for filtering air in tunnels which can be positioned in a site and set up for operation rapidly and simply. In particular, the present invention has for an aim to provide a filtering apparatus which allows machining in existing tunnels during successive nights, without the tunnel having to be closed to traffic during the day.
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Another aim of the present invention is to propose an apparatus for filtering air in tunnels which can filter an air flow in a more efficient way.
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Yet another aim of the present invention is to propose an apparatus for filtering air in tunnels which is extremely easy to transport close to a site.
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The technical purpose indicated and the aims specified are substantially achieved by an apparatus for filtering air in tunnels with the technical features described in one or more of the claims herein.
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Further features and advantages of the present invention are more apparent from the non-limiting description which follows of a preferred, non-limiting embodiment of an apparatus for filtering air in tunnels, illustrated in the accompanying drawings, in which:
- Figure 1 is a side view of an apparatus for filtering air in tunnels according to the present invention in a first operating configuration;
- Figure 1a is a view of a detail of the apparatus of Figure 1;
- Figure 2 is a front view of the apparatus of Figure 1;
- Figure 3 is a longitudinal view from behind of the apparatus of Figure 1 in a second operating configuration;
- Figure 4 is a side view of the apparatus of Figure 1 in a third configuration for transportation; and
- Figure 5 is a view of another detail of the apparatus of Figure 1.
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With reference to the accompanying drawings, the numeral 1 denotes as a whole an apparatus for filtering air in tunnels according to the present invention.
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The apparatus 1 can advantageously be used at sites for making a new tunnel or at sites for carrying out maintenance work on existing tunnels. Specifically referring to the latter case, tunnel maintenance work may, by way of example only, typically consist of demolition of the tunnel concrete vault followed by rebuilding of it.
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In any case, this type of work generates dust which may be conveyed relative to the place where a machining tool is located by an air flow which may be present in the tunnel.
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Because of that, the apparatus 1 is advantageously positioned downstream of the position where the work takes place, with reference to the direction of movement of the air flow.
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The apparatus 1 comprises a mobile frame 2 which can be positioned inside a tunnel "G" and which extends along a longitudinal main axis of extension "A" of the apparatus 1.
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The frame 2 is equipped with movement means 3 which allow the apparatus 1 to be moved to the site and to move along the tunnel "G" easily. In the embodiment described the movement means 3 are wheels which may be of the road or rail type, depending on the type of site. For example, in alternative embodiments not illustrated, the movement means 3 may comprise crawler tracks or other items.
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On the frame 3 there is a filtering unit 4 which separates, in the known way, a solid component (dust) from an air flow to be filtered.
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The filtering unit 4 comprises a plurality of banks of filters 5 of the known type arranged one after another. In the embodiment illustrated the filters 5 are dry filters. However, the present invention may be applied to filtering units comprising filters of any type (wet, etc.) according to requirements.
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The filtering unit 4 has an intake section 6 and a delivery section 7. The banks of filters 5 are arranged between the intake section 6 and the delivery section 7.
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The filtering unit 4 also comprises a hopper 8 for collecting the dusts separated from the air flow to be filtered by the banks of filters 5. The hopper 8 is located below the banks of filters 5.
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A screw feeder or a chain conveyor (not illustrated in the accompanying drawings) is positioned inside the hopper to empty the dusts from it.
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The filtering unit 4 also comprises a fan 9 which generates the air flow. As illustrated, in the embodiment described the fan 9 is located at the delivery section 7.
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The apparatus 1 also comprises a plurality of intake inlets 10 in fluid communication with the intake section 6 of the filtering unit 4. The intake inlets 10 draw the air flow to be filtered from an extraction zone and direct it towards the filtering unit 4.
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In accordance with the embodiment described, the intake inlets 10 comprise a first portion 10a substantially having the shape of a parallelepiped with a substantially rectangular open face forming an entry section 11 of the intake inlets 10. Advantageously, each entry section 11 is positioned in a plane perpendicular to the longitudinal axis "A" of the apparatus 1 in such a way that it intercepts the air flow to be filtered more efficiently. In this way, in practice the entry sections 11 are opposite the machining zones.
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The intake inlets 10 also comprise a second portion 10b, connected to the first portion 10a, and forming a connecting body needed to connect the intake inlets 10 to the intake section 6.
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The apparatus 1 also comprises at least one auxiliary intake inlet 12 in fluid communication with the intake section 6 of the filtering unit 4 located close to the flat supporting surface "S" for the apparatus 1 (usually the ground). In the embodiment described, the apparatus 1 comprises two auxiliary intake inlets 12 positioned on opposite sides of the frame 2.
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The auxiliary intake inlets 12 also comprise a first portion 12a substantially having the shape of a parallelepiped with an open lateral face forming a corresponding entry section and a second portion 12b, connected to the first portion 12a, and forming a connecting body needed to connect the auxiliary intake inlets 12 to the intake section 6. The apparatus 1 comprises a plurality of intake ducts 14, each connected to a respective intake inlet 10 or auxiliary intake inlet 12, and connected to the intake section 6 of the filtering unit 4 to convey the air flow to be filtered towards the filtering unit 4.
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In particular, each duct 14 has a first end 14a and a second end 14b, opposite the first end. The first end 14a of each duct 14 is fixed to the second portion 10b of the respective intake inlet 10 or to the second portion 12b of the respective auxiliary intake inlet 12.
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In the embodiment illustrated, the ducts 14 have a substantially circular cross-section, are extendable and, preferably, are made of flexible plastic material. Alternatively, they may also be made of metal material.
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In embodiments not illustrated, the ducts 14 may be semi-rigid and therefore comprise a supporting structure (not illustrated in the accompanying drawings) which gives the extended ducts 14 particular structural properties, or they may be rigid and have their own structural capacities. Again in that case they may be made either of plastic material or metal material.
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Advantageously, the apparatus 1 also comprises a connector 15 located between the filtering unit 4 and the ducts 14. In particular, the connector 15 is positioned between the intake section 6 and is connected to the ducts 14.
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In the embodiment described, the connector 15 substantially has a prismatic shape with its polygonal base surfaces 15a parallel with the intake section 6 and lateral surfaces 15b to which the ducts 14 are connected.
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In particular, the connector 15 comprises connecting sleeves 16 located on the lateral surfaces 15b. The ducts 14 are coupled to the connector 15 using the connecting sleeves 16. Advantageously, as is more apparent in the description below, the intake inlets 10 can move between a plurality of operating positions, so that, during use, they are close to the vaulted wall of the tunnel "G" (Figure 2) and in contact or almost in contact with it. To close the space formed between each intake inlet 10 and the tunnel "G", the intake inlets 10 may comprise a stop (not illustrated in the accompanying drawings) made of flexible material, for example rubber, located on a face of each intake inlet 10, which, during use, faces directly towards the wall of the tunnel "G".
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In particular, in the embodiment illustrated, the intake inlets 10 can move in straight directions of movement "B" substantially extending radially from the frame 2 (therefore, substantially from the longitudinal axis "A" of the apparatus 1). Moreover, again in the embodiment illustrated, the directions of movement "B" lie in a plane perpendicular to the longitudinal axis "A" of the apparatus 1.
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However, in other embodiments, the intake inlets 10 may even be able to move along movement trajectories which are not straight, for example along arcs of a circle centred on axes positioned in planes perpendicular to the longitudinal axis "A" of the apparatus 1. This is also described in more detail below.
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In the embodiment illustrated, the apparatus 1 also comprises adapting means 17 (whose main function is described in more detail below) acting on the intake inlets 10 to move them reversibly along the respective movement trajectories (directions "B" or other) at least between their different operating positions.
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In accordance with the preferred embodiment, the adapting means 17 comprise a plurality of extendable arms 18, each connected to a respective intake inlet 10. Each extendable arm 18 has a first end 18a connected to the frame 2 and a second end 18b, opposite the first end, able to move and connected to the respective intake inlet 10 in a fixed or removable way depending on requirements. In more detail and as illustrated in Figure 1, the first end 18a of each extendable arm 18 is connected to the connector 15.
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Preferably, in the embodiment illustrated the extendable arms 18 are telescopic rods equipped with suitable actuating elements of the known type with manual or automated operation. By way of example only, the actuating elements comprise a winch 19 and a chain 20 connected to the mobile part of the extendable arm 18.
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In alternative embodiments (not illustrated), the extendable arms 18 may consist of pneumatic or hydraulic cylinders operated by suitable dedicated circuits. In this case, the pneumatic or hydraulic cylinders also form the actuating elements needed to extend and shorten the extendable arms 18.
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In other embodiments, also not illustrated, the extendable arms may consist directly of the ducts 14, and vice versa.
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Advantageously, in the embodiment illustrated each extendable arm 18 can also rotate at its first end 18a between an operating configuration in which each extendable arm 18 is positioned in a plane substantially perpendicular to the longitudinal axis "A" of the apparatus 1 and a configuration for transportation in which each extendable arm 18 is positioned substantially parallel with the longitudinal axis "A" of the apparatus 1.
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As already indicated, in the operating configuration, each extendable arm 18 is advantageously positioned at a right angle to the longitudinal axis "A". In other words, in the accompanying drawings each extendable arm 18 is angled according to the direction of movement "B" of the respective intake inlet 10 between its different operating positions.
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In contrast, in the configuration for transportation, each extendable arm 18 is fully retracted and is folded towards the frame 2 in such a way as to reduce as far as possible the transversal dimension of the apparatus 1. This is intended to allow the apparatus 1 to be transported along the roads in accordance with regulations relating to the maximum transversal dimensions of vehicles allowed.
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In this configuration for transportation, as shown in Figure 4, the intake inlets 10 and the ducts 14 may preferably be removed from the rest of the apparatus 1 and transported separately to allow a further reduction in the dimensions of the apparatus 1. Obviously, in this case, the intake inlets 10 must be connected to the adapting means (that is to say to the arms 18) in a removable fashion.
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In contrast, the auxiliary intake inlets 12 are supported by auxiliary arms 30 connected in such a way that they project from the frame 2. The auxiliary arms 30 are not usually extendable. However, the auxiliary arms 30 can advantageously rotate close to their end near the frame 2 again to reduce the transversal dimension of the apparatus 1 and adopt the configuration for transportation described above.
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According to the present invention, the apparatus 1 also comprises barrier means 21 for creating a barrier designed, when in use, to longitudinally divide into two zones a tunnel "G" and in this way to at least partly delimit the extraction zone from which the air flow to be filtered will be drawn.
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The barrier formed by the barrier means 21 has a face which, when in use, is facing towards the zone to be filtered, to which the intake inlets 10 are operatively connected.
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In particular, in the preferred embodiment illustrated, the intake inlets 10 are distributed at least along an upper outer portion of the barrier, whatever the operating configuration adopted by the barrier (described below). Advantageously, the intake inlets 10 are distributed along the upper outer portion of the barrier in the most regular and symmetrical way possible relative to a vertical plane comprising the longitudinal axis "A" of the apparatus.
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As is more apparent below, in the embodiment illustrated, the barrier means 21 are neither defined or definable when the intake inlets 10 are in their non-operating position, and/or when the adapting means are in their transportation position. In other words, the barrier means 21 are definable only when the intake inlets 10 are in their operating positions.
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The barrier means 21 comprise a plurality of barriers 22 supported at least indirectly by the adapting means 17 and/or by the frame 2 using connecting and supporting means 23. In particular, in the embodiment illustrated, the connecting and supporting means 23 are indirectly connected to the adapting means since they are directly supported by the intake inlets.
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Preferably but not exclusively, the barriers 22 are made of flexible material. By way of example, the barriers 22 may be plastic sheets made of PVC or another material.
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In the preferred embodiment, the connecting and supporting means 23 comprise a plurality of rollers 24, 26 connected to the intake inlets 10. The barriers 22 are wound on these rollers in such a way that they can be unwound from them.
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In more detail, the connecting and supporting means 23 comprise a plurality of central rollers 24, each connected to a respective intake inlet 10. Each central roller 24 is positioned along a first edge 25a of the intake inlet 10 in question closest to the frame 2. In other words, the first edge 25a is the edge of the entry section 11 which in practice is positioned close to the wall of the tunnel "G" (Figure 1a).
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In even more detail, each central roller 24 is positioned with its longitudinal axis "C" of rotation substantially at a right angle to the direction of movement "B" of the intake inlet 10 in question. The longitudinal axis "C" of rotation lies in a plane substantially perpendicular to the longitudinal axis "A" of the apparatus 1.
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In this way, once the intake inlets 10 are in the operating position the barriers 22 wound on the central rollers 24 can be unwound from the respective intake inlets 10 towards the frame 2 with a substantially radial direction in a direction parallel with the direction of movement "B" of the intake inlets 10.
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The connecting and supporting means 23 also comprise a pair of lateral rollers 26 connected to each intake inlet 10 and positioned on opposite sides of each intake inlet 10. More specifically, the lateral rollers 26 are connected to the intake inlets 10 at a second edge 25b of the intake inlets 10.
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This second edge 25b is opposite and substantially parallel with the first edge 25a and, in practice, is substantially close to the wall of the tunnel "G".
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When the intake inlets 10 are in their operating positions, the lateral rollers 26 extend in such a way that they project from the second edge 25a, in a plane perpendicular to the longitudinal axis "A" and at an angle (preferably adjustable) to the axis of rotation "C" of the central rollers 24, such that in practice they follow the profile of the tunnel "G". In other words, the projecting ends of the lateral rollers 26 converge towards the frame 2 of the apparatus, advantageously in such a way that their axis of rotation is substantially perpendicular to a radial direction coming out of the longitudinal axis "A". In this position, even the barriers 22 wound on the lateral rollers 26 can be unwound towards the frame 2 with a substantially radial direction to form the completed barrier means 21.
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When the barrier means 21 are active and the barriers 22 are unwound and extended, they are held in that position by suitable hooking means (not illustrated in the accompanying drawings). In other words, the hooking means allow stable connection between a free edge of the barriers 22 and, for example, the connector 15 (usually to the frame).
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Advantageously, both the central rollers 24 and the lateral rollers 26 comprise elastic return means (of the known type and therefore not illustrated) acting on the barriers 22 to rewind the barriers 22.
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The return means therefore allow rapid rewinding of the barriers 22 when the barrier means 21 must be deactivated.
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Moreover, advantageously, the return means keep the barriers 22 under tension when the barrier means 21 are active, in this way helping to limit and eliminate air leaks between the barriers 22. Advantageously, when the barrier means 21 are disabled, the lateral rollers 26 can be removed to reduce the dimensions. Alternatively, the lateral rollers 26 may be folded towards each other above the respective intake inlets 10.
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It should be noticed that when the barrier means 21 are active, the barriers 22 partly overlap each other.
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In an embodiment not illustrated, the barrier means 21 also comprise sealing means acting between the barriers 22 to prevent a dusty air flow from leaking between the barriers 22. For example, the sealing means may comprise Velcro strips or magnetic strips/bars for stably connecting the overlapping barriers 22 to each other.
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Moreover, the sealing means may also comprise a rim (not illustrated) which can be positioned along the wall of the tunnel "G" at the intake inlets 10 and the barrier means 21 to prevent a dusty air flow which strikes the walls of the tunnel "G" from getting past the barrier means 21.
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In an alternative embodiment not illustrated, the barriers 22 are made of rigid material. In other words, the barriers 22 may consist of rigid panels made in a single piece - or, alternatively, in separate modules - coupled to the adapting means 17 and/or to the frame 2 to form the barrier means 21. In accordance with the present invention, in general the apparatus 1 comprises the adapting means 17 for varying the configuration of the barrier formed by the barrier means 21 between a minimum extension operating configuration (corresponding to the configuration of the intake inlets in Figure 3 in which the barrier means 21 are not shown) and a maximum extension operating configuration (Figure 4), so that the apparatus can be used with tunnels which have various cross-sections.
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As already indicated, in the accompanying drawings the barrier operating configuration is varied simply by radial extension or retraction of the arms 18, but in other embodiments (not illustrated) this may also be achieved in another way, for example by rotating the arms (which in that case are not necessarily extendable) from a set-up similar to that for transportation to the set-up of Figure 4. Increasing the angle between the arms and the longitudinal axis "A" also increases the radial extension of the barrier. However, usually, when the arms are rotated the minimum extension configuration is not that corresponding to positioning of the arms in the position for transportation (also corresponding to a barrier means configuration for transportation), but a configuration corresponding to a rotation of the arms through an angle such that the radial dimension of the barrier is greater than the radial dimension of the other parts of the apparatus 1. The apparatus 1 also comprises a plurality of regulating valves 27 preferably positioned at the connector 15.
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Each valve 27 is connected to a respective duct 14 in such a way as to activate and deactivate the air flow to be filtered, passing in the duct 14 in question. In the embodiment described, the valves 27 are butterfly valves.
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In the embodiment described, the valves 27 are located between each sleeve 16 and the corresponding duct 14.
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Advantageously, the apparatus 1 also comprises control means 28 for the valves 27 for moving the valves in a selective way and independently, or in a synchronised way, depending on requirements.
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In other words, the control means 28 allow the valves 27 to be opened and closed either each independently of the others or all or part of them simultaneously. In that way, according to a first theory, the control means 28 open all of the valves 27 to allow all of the intake inlets 10 to suck in air evenly along the whole tunnel "G".
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According to a second theory, the control means 28 open some valves 27, closing others, to limit air intake only to several intake inlets 10 so as to concentrate and maximise the intake capacity only at a desired zone of the tunnel "G" (usually that closest to the point where the work is taking place).
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In the embodiment illustrated, the control means 28 comprise actuators 29 acting on each valve 27 (Figure 5). The actuators 29 may be pneumatic or hydraulic. In that case, the control means 28 may also comprise a distribution valve (not illustrated) on the feed circuit for the actuators 29, allowing identification of the valves 27 to be kept open or closed.
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The invention achieves the preset aims and brings important advantages.
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Since the apparatus comprises not just the extractor system, but also the barrier means and adapting means, the time needed to set up the apparatus is drastically reduced. Special supporting structures on which to mount the barriers no longer have to be set up, nor is subsequent positioning of the filtering extractor devices necessary.
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Therefore, advantageously, the barrier means set up and disassembly operations are performed at the same time as the installation of the whole apparatus, significantly reducing both the time and personnel needed to carry out these operations. Moreover, overall filtering efficiency for the air in the tunnel is significantly increased by the possibility of concentrating the extraction capacity at precise points of the vault or distributing it over the entire vault, depending on requirements.
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Finally, since the apparatus may rapidly and simply adopt a compact configuration, the apparatus can easily be transported to the site and along the site.
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It should also be noticed that the present invention is relatively easy to produce and that even the cost linked to implementing the invention is not very high.
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The invention described may be modified and adapted in several ways without thereby departing from the scope of the inventive concept.
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Moreover, all details of the invention may be substituted with other technical equivalent elements and in practice all of the materials used, as well as the shapes and dimensions of the various components, may vary according to requirements.
