Scutching plant for processing plant fibers

Abstract

Scutching plant for processing plant fibers The invention relates to a scutching plant (1), and a corresponding control method, for processing plant fibers comprising: - several processing devices (7, 9) having a closing hood or without a closing hood, - a dust extraction system (30) configured to circulate extraction flows through at least one extraction outlet at the level of a device (7) having a closing hood and at least one extraction outlet at the level of a device (9) without a closing hood, in which the extraction system (30) also includes one or more control means (38) for regulating the flow rate of one or more extraction outlets,and a control means (24) for controlling the control means (38) so as to decrease the suction flow rate at a device (9) without a closing cover when said device (9) without a closing cover is stopped, and to increase the suction flow rate at a device (7) with a closing cover when the closing cover is opened. Figure for the abbreviation: Fig. 1.

Description

Title of the invention: Scutching plant for processing plant fibers Technical field

[0001] The present invention relates to the field of processing plant stems, such as flax or hemp. More specifically, the invention relates to the field of scutching plant stems to obtain treated plant fibers, and in particular to the treatment of dust emitted during the scutching operations. Previous technique

[0002] The purpose of flax stalk scutching is to extract the fibrous part, or flax fiber, from the plant stem and to eliminate the woody parts and the shives.

[0003] To achieve this, a scutching plant is commonly used, which most often comprises, considered successively according to the direction of movement of the flax stalk within the scutching plant, a flax stalk unwinding station and a flax fiber winding station. Between the unwinding station and the winding station is an extraction station that allows the fibers to be extracted from the woody core of the plant. This is generally a mechanical extraction of the fibers, carried out by beating the stalks to remove the woody core. The extraction station traditionally includes a crushing and shearing module.

[0004] Several operations precede these actual scutching operations intended to extract the fibers from the stems; these upstream operations consist of arranging the flax stems, aligning them, removing the seeds, extracting foreign bodies, etc. For example, among these operations, a ginning operation is carried out, such as that described in the French patent application registered under number FR.0605893, the purpose of which is to extract the capsules and seed-bearers found in the flax stems, this also making it possible to extract the pebbles and other foreign bodies found inside the flax layer before the scutching operations.

[0005] The flax stalk bales are brought one by one into the unwinding station where they are unwound and spread flat to form the flax web. One or more conveyors, for example belts and / or rollers, allow the flax web to move in the direction of travel.

[0006] The long fibers extracted by scutching are intended mainly for textiles, while the other co-products are used in different sectors: the short fibers are intended for textiles, insulation or papermaking; the seeds for oil production or animal feed; the shives are intended for furniture or bedding in particular.

[0007] However, such treatment devices have the disadvantage of generating a lot of dust which is sometimes harmful to the health of operators present near the scutching plant.

[0008] It is known to equip scutching plants with extraction systems to collect the dust emitted during the various processes. However, with increasing requirements regarding dust concentration in the air, extraction systems are becoming more and more efficient in terms of suction flow rate, and therefore more and more energy-intensive.

[0009] It is therefore known to provide, where possible, treatment installations with a closing hood. Such treatment installations are thus confined by their casing, which limits dust emissions at their level, and therefore the volumes of suction required.

[0010] However, in the event of unclogging, maintenance or servicing operations, access to said treatment installations, in particular the opening of the closing hood, releases or exposes the operator to dust which was, until then, confined in the treatment device.

[0011] The multiplication of suction outlets or the increase in flow rates applied to the different outlets leads to suction systems whose sizing becomes expensive, whether in terms of installation or operation. Description of the invention

[0012] The present invention aims to solve the various technical problems mentioned above. In particular, the present invention aims to provide a scutching plant that limits dust exposure for people working nearby. More specifically, the present invention aims to provide a scutching plant with an improved extraction system to remove harmful dust from people working nearby, while maintaining low energy consumption.

[0013] Thus, according to one aspect, a scutching plant is proposed for the processing of plant fibers, in particular flax or hemp, comprising: - several devices for processing said plant fibers mounted between an inlet and an outlet of said installation, one or more of said devices having a closing cover and one or more of said devices being without a closing cover, - a dust extraction system for the dust emitted during the processing of said plant fibres, the extraction system comprising several extraction ports and being configured to circulate extraction flows through said extraction ports, at least one extraction port being intended for the extraction of dust emitted at the level of said device(s) comprising a closing cover and at least one suction inlet intended to suck up dust emitted at the level of said device(s) lacking a closing cover.

[0014] The suction system also includes one or more flow control means, for example one or more dampers, configured to regulate the flow drawn in by one or more suction inlets at said device(s) without a closing cover and at said device(s) with a closing cover. The suction system also includes a control means for said flow control means, the control means being configured to command said control means to decrease the suction flow rate at the inlet at a device without a closing cover when said device without a closing cover is stopped, and to increase the suction flow rate at the inlet at a device with a closing cover when the closing cover of said device with a closing cover is opened.

[0015] More specifically, the suction system takes into account the machine's operation to adjust the suction flow rates applied to the different parts of the installation accordingly. Thus, for processing devices without a closing hood, such as, for example, the bale unroller or the feeding table, the applied suction flow rate is high except when it is stopped. Similarly, for processing devices with a closing hood, such as the connecting table, the divider, the grinders, or the opener and sheller if present, the suction flow rates remain limited during normal operation of the installation, but are increased when the closing hood is opened, for example, during maintenance or clearing operations.

[0016] A treatment device comprising a closing hood is defined as a treatment device comprising a casing (or fairing), particularly a peripheral one, with a closing hood. Thus, when the closing hood is closed, the space where the treatment takes place is confined by the casing and possibly the chassis of the device, except perhaps at the inlets and outlets and / or at the openings in the casing. Such a treatment device thus makes it possible to limit the dispersion of dust that may be emitted by the layer of plant stems during its treatment by the device.

[0017] The suction flow rates applied to treatment devices without a closing cover, or to treatment devices with an open closing cover, vary from one installation to another and are generally greater than or equal to 6,000 m³ / h, particularly greater than or equal to 11,000 m³ / h, or even greater than or equal to 16,000 m³ / h. Thus, the suction flow rates are generally between 6,000 m3 / h for older installations, and 16,000 m3 / h for the most recent installations or even more.

[0018] Preferably, the control means is configured to control said or said control means to decrease the suction flow rate of the mouth at the level of the device without a closing cover and to increase the suction flow rate of the mouth at the level of the device with a closing cover, when the device without a closing cover is stopped and the closing cover of said device having a closing cover is open.

[0019] More specifically, modifying the suction flow rates requires two conditions: first, the scutching plant must be stopped, and second, a treatment device with a closing hood must be opened. In this case, the operation of the suction system is modified to decrease the flow rate at the devices without a hood and to increase the flow rate at the device with the closing hood open. Thus, since the closing hood of a treatment device with a hood can generally only be opened if the scutching plant is stopped, the suction system according to the invention makes it possible to reduce the suction at the devices without a hood and increase it at the device with the closing hood open.The overall suction flow rate of the suction system is therefore not increased, but is distributed differently within the scutching plant to protect the people working on the scutching plant.

[0020] Preferably, when the device without a closing cover is stopped and the closing cover of said device having a closing cover is opened, the control means is configured to control said or said control means so that a part of the flow removed from the suction mouth located at the level of the device without a closing cover is added to the flow of the suction mouth located at the level of the device having a closing cover.

[0021] In this case, the overall suction flow rate of the suction system remains substantially the same during the different states of the scutching plant, but the distribution of flow rates within the scutching plant is modified so as to extract more suction where it is needed. Thus, when the plant is shut down, the reduction in suction flow rate at devices without a closing cover is used to increase the suction flow rate at a device with an open closing cover. Therefore, the suction system according to the present invention improves the safety of personnel working on the plant, without increasing the overall suction flow rate, but simply by redirecting the flow rates to areas where dust emissions become potentially harmful.

[0022] Preferably, the scutching plant comprises one or more conveyors configured to transport the plant fibers from the inlet to the outlet of the installation, passing through the various processing devices, and a device without a closing hood is stopped when the conveyor present at the level of said device is stopped, or in which the closing hood of a device having a closing hood is only opened when the conveyor present at the level of said device having a hood is stopped.

[0023] To determine the operating status of the installation, and consequently control the flow rates of the suction inlets, the suction system can use the operation of the conveyor(s) of the scutching plant. Indeed, it is the conveyor(s) that transport the continuous stalk along the scutching line, through the various successive processing units. Thus, when a conveyor is stopped, this means, at a minimum, that the processing units without a closing cover fed by that conveyor are stopped and, consequently, that dust emissions are reduced to their level.

[0024] Similarly, for processing devices with a closing hood, simply detecting the opening of the closing hood is sufficient to identify the need for additional local suction. The suction system control means can therefore advantageously use the information provided by the various sensors of the scutching plant, particularly the sensors connected to the closing hoods, to determine accordingly the suction flow rates to be applied at different locations within the plant.

[0025] Preferably, the suction system comprises a main manifold to which the various suction outlets are connected, possibly via regulating means.

[0026] To facilitate the suction system, it can be built around a main manifold to which the various suction outlets are connected. Control means can then be provided at different locations to locally modify the applied suction flow rates.

[0027] Preferably, each suction outlet located at the level of a device comprising a closing cover, includes a regulating means and / or the suction system includes a common regulating means for several suction outlets located at the level of one or more devices comprising a closing cover.

[0028] For treatment devices with a closing cover, control means may be provided at each suction inlet, particularly if there is only one suction inlet per closing cover. Alternatively, if several suction inlets are mounted on a single closing cover, then said suction inlets may be controlled by a single, common control means, governed in particular by the state of the closing cover.

[0029] Preferably, each suction outlet located at the level of a device without a closing cover, includes a regulating means and / or the suction system includes a common regulating means for several suction outlets located at the level of one or more devices without a closing cover.

[0030] For treatment devices without a closing cover, control means may be provided at each suction inlet, particularly if there is only one suction inlet per treatment device. Alternatively, if several suction inlets are mounted on the same treatment device without a closing cover, then said suction inlets may be controlled by a single, common control means, governed in particular by the state of said device without a closing cover.

[0031] Preferably, when the installation is in operation, the suction system is configured to apply a suction flow rate at the level of devices without a closing cover, and to apply a reduced suction flow rate at the level of devices with a closing cover.

[0032] In the normal operation of the scutching plant, in addition to the suction provided for devices without a closing cover, it is also possible to provide reduced suction for processing devices with a closing cover. Such reduced suction can ensure sufficient negative pressure inside the processing devices, relative to the outside, to prevent any dust leakage, particularly at the inlets and outlets. Furthermore, such reduced suction for processing devices with a closing cover does not prevent increased suction if the closing cover is opened.

[0033] Preferably, the inlet is configured to receive plant stems in the form of agricultural bales, and a device without a closing hood comprises: an agricultural bale unwinding means configured to provide a swath of stems by unwinding an agricultural bale, optionally a feeding table mounted downstream of the unwinding means and configured to allow an operator to check the quality of the swath of fibers obtained after unwinding the agricultural bale, and optionally a preparation means mounted upstream of the unwinding means and configured to allow an operator to prepare the agricultural bale for unwinding.

[0034] Among the processing devices without a closing hood but with dust extraction, there may thus be the means for preparing the agricultural bale at which the strings encircling the agricultural bale are cut, the means for unrolling the agricultural bale, or the feeding table at the level of during which any clumps are untangled and stones removed. Indeed, the presence of operators is generally still necessary with such equipment, which can generate a lot of dust. In this case, the open casing of such treatment devices may include suction vents to capture the dust as close as possible to the plant stems.

[0035] Preferably, the outlet is configured to provide plant fibers in the form of a bale, and a device without a closing hood includes a means for baling the plant fibers.

[0036] Here again, at the level of baling the tow obtained at the exit of the scutching process, it may still be necessary to have an operator to monitor the proper functioning of the device, which prevents the presence of a closing hood, and therefore requires a special aspiration.

[0037] According to another aspect, a method for controlling a suction system in a scutching plant for processing plant fibers is also proposed. The plant comprises several devices for processing said plant fibers mounted between an inlet and an outlet of the plant. One or more of these devices have a closing cover, and one or more of these devices do not have a closing cover. According to the method, suction flows are circulated to extract the dust emitted at the level of said device(s) without a closing cover, and optionally at said device(s) with a closing cover, when the plant is in operation.In particular, the suction flow rate at a device without a closing cover is decreased, for example by controlling one or more control means, when said device without a closing cover is stopped, and the suction flow rate at a device with a closing cover is increased, for example by controlling one or more control means, when the closing cover of said device with a closing cover is opened.

[0038] Preferably, the suction flow rate at the device without a closing cover is decreased, for example by controlling one or more control means, in order to increase the suction flow rate at the device with a closing cover, for example by controlling one or more control means, when the device without a closing cover is stopped and the closing cover of said device having a closing cover is opened. Brief description of the drawings

[0039] [Fig.1] Fig.1 represents a perspective view of a scutching installation with a suction system, according to the invention;

[0040] [Fig.2] Fig.2 represents, in perspective, a view of the entrance to the installation re- presented in [Fig.1];

[0041] [Fig.3] Fig.3 represents, in perspective, a view of an intermediate part of the installation shown in Fig.1;

[0042] [Fig.4] [Fig.4] shows, in perspective, a view of the outlet of the installation shown in [Fig.1]; and

[0043] [Fig.5] Fig.5 represents, in perspective, an example of a register for regulating an aspiration flow, used by the installation shown in Fig.1. Description of the implementation methods

[0044] Figure 1 illustrates, in perspective, an example of a scutching plant 1 according to the present invention. The purpose of the scutching plant 1 is to process plant stems supplied, for example, in the form of agricultural bales, to obtain plant fibers, or tow, for example in the form of bales.

[0045] Thus, the scutching installation 1 has an inlet 2 and an outlet 4, and includes various processing devices mounted between the inlet 2 and the outlet 4 of the scutching installation.

[0046] In the example shown in Figures 1 and 2, the inlet 2 is configured to receive plant stems in the form of agricultural bales 6, in particular on a reserve table on which the agricultural bales 6 are stored pending their processing by the scutching installation 1. The scutching installation 1 thus includes, at its inlet 2, processing devices enabling it to obtain, from such agricultural bales 6, a continuous layer of plant stems suitable for being transported by one or more conveyors and processed successively in different processing devices.

[0047] Among the processing devices, some are processing devices 7 having a closing hood, and others are processing devices 9 without a closing hood.

[0048] In particular, a treatment device 7 comprising a closing hood, or enclosed treatment devices, is defined as treatment devices having a casing, preferably peripheral, and optionally a frame surrounding a space where the treatment operations are carried out, and closed by a closing hood. For such treatment devices 7 with a closing hood, all operations performed on the plant stems or fibers take place within said confined space, delimited in particular by the casing, which limits the release of elements, such as dust, to the outside of the treatment device 7, except possibly at the points where the plant stems or fibers enter and exit the treatment device and / or at openings in the casing.

[0049] Thus, the installation 1 comprises successively, at the level of the inlet 2, a preparation means 8, an unwinding means 10 and a feeding table 12.

[0050] The preparation means 8, or preparation table, can be configured to move laterally to one side of the scutching unit 1 by translation and is configured to allow the bale 6 to rotate. The bale 6 can then be prepared by an operator P positioned in front of the preparation means 8 for further processing. In particular, the operator P can then remove, by rotating the bale 6, the peripheral twine holding the plant stems together in bale form, as well as any other unwanted material present on the surface of the bale 6. The operator P can also locate the beginning of the spiral to prepare the bale for unwinding.

[0051] When the ball 6 is ready, it is then moved to the unwinding means 10.

[0052] The unwinding means 10 is configured to rotate the agricultural bale 6 on its own axis in order to unwind it as a continuous sheet. The agricultural bale 6 is formed from a continuous sheet of plant stems wound around itself in a spiral to obtain the bale. The unwinding means 10 thus allows the reverse operation to be performed, resulting in the continuous sheet of plant stems at the output. For this operation as well, the presence of an operator P is often necessary to ensure the correct unwinding of the spiral of stems and, if necessary, to assist in separating the sheet from the rest of the spiral, most often by disentangling the stems from each other.

[0053] Finally, the continuous sheet is conveyed by the feeding table 12. The feeding table 12 allows the condition and quality of the continuous sheet obtained by unwinding the agricultural bale 6, as well as its flow rate, to be checked before it is fed into the subsequent processing devices. The feeding table 12 includes, in particular, a conveyor transporting the continuous sheet from the unwinding means 10 to the subsequent processing devices, and allowing an operator P to inspect the continuous sheet, for example, to remove any foreign bodies present, separate any stems into piles, etc.

[0054] Following preparation table 12, the continuous sheet of plant stems can then be processed to obtain, in particular, the desired plant fibers.

[0055] The preparation means 8, the unwinding means 10, and the feeding table 12 are devices 9 without a closing cover: they are thus open to allow an operator P to work directly on them, which also exposes said operator to the elements released during the treatment applied to the plant stems, in particular dust. In order to limit such exposure, the devices 9 without a closing cover may, in particular, include one or more extraction vents integrated into the open casing of the treatment device 9, for example, extraction hoods, configured to extract the dust as close as possible to the plant stems that release it and before it reaches the operator P working on said treatment device 9.

[0056] Among the subsequent plant stem processing devices, the scutching installation 1 may thus include: an opener 14, optional and configured to open the slab and remove any remaining foreign bodies; an optional thresher 16 configured to recover the seeds from the stems; an optional connecting table 18 configured to align the feet of the stems in the continuous slab; a divider 20 configured to progressively accelerate the speed of movement of the continuous slab and / or to regulate the load of the processing devices mounted downstream of the divider 20; and one or more crushers 22 configured to break the woody part of the flax stem, for example successively at the head and feet of the plant stems.

[0057] The opener 14, the thresher 16, the connecting table 18, the divider 20, and the crushers 22 are devices 7 comprising a closing hood: they are thus closed to perform the processing operations on the plant stems or fibers in a safe and contained manner. In particular, elements such as dust that may be released during processing in said devices 7 with closing hoods remain trapped, notably by the closing hood. In order to collect the dust and limit possible leaks to the outside through the openings of the devices 7, the devices 7 comprising a closing hood may also include a reduced suction system, via one or more suction nozzles, designed to create a negative pressure in the processing area, relative to the outside. The dust thus released in the processing area is then collected and expelled from the processing device 7 with closing hood.

[0058] Furthermore, the processing devices 7 with a closing hood advantageously include means, for example sensors, configured to stop the operation of the processing device 7 when the closing hood is opened, or to allow the closing hood to be opened only when the processing device 7 is stopped. Such means thus make it possible to protect operators P who may work on the processing device 7, preventing injuries as well as exposure to dust. In particular, the scutching plant 1 may include a control means 24 configured to control different means of the scutching plant 1 according to its operation, for example, to stop all the processing devices of the scutching plant 1 when the closing hood of a processing device 7 is opened.The control means 24 can thus receive the data provided by the sensor(s) linked to the various closing covers of the processing devices 7 with closing cover.

[0059] The fibers are then conveyed, from the outlet of the crushers 22, to drums, for example primary and secondary, to be subjected to a cleaning scraping, particularly on the foot side then on the head side, then towards mills configured to smooth the plant fibers thus cleaned.

[0060] At the outlet 4 of the installation, the plant fibers exiting the drums are conveyed, as illustrated in [Fig. 4], onto a sorting bar 26, which includes a conveyor, for inspection and sorting, and then to a winder 28 supplying the fibers in batches, particularly in bales, at the outlet of the installation 1. Like the preparation means 8, the unwinding means 10, or the feeding table 12, the winder 28 is a processing device 9 without a closing cover, specifically to allow the supply of bales of plant fibers at outlet 4 of the scutching installation 1.

[0061] In order to convey the plant stems or plant fibers between the different processing devices of the scutching installation 1, the installation also includes one or more conveyors 29, such as those of the feeding table 12 and the sorting bar 26. The conveyors 29 thus make it possible to regulate the operation of the scutching installation, by supplying or, on the contrary, stopping the supply of plant stems or fibers to the processing devices.

[0062] In order to limit the exposure of operators P to elements released by plant stems, in particular dust, the scutching installation 1 includes a suction system 30. The suction system 30 thus makes it possible to collect the dust sucked up at the level of the different processing devices of the scutching installation 1, whether they are processing devices 7 with a closing hood or processing devices 9 without a closing hood.

[0063] The suction system 30 thus comprises a main collector 32 forming a main suction line to which secondary lines 34 are then connected, linking the main collector 32 to the various suction outlets 36 of the scutching plant 1.

[0064] Alternatively, the suction system 30 may include different main manifolds, for example a manifold for the upstream part of the installation and a manifold for the downstream part of the installation.

[0065] The suction system 30 therefore includes suction inlets 36 mounted at the ends of the pipes, particularly secondary pipes 34. The suction inlets 36 can be independent of the processing devices. For example, at the processing devices 9 without a closing cover, suction inlets 36 can be provided above the processing area, for example above the conveyor 29 of the feeding table 12. Such suction inlets 36 thus make it possible to act on the processing area of ​​the corresponding device 9, while also being able to be repositioned or moved for better operation.

[0066] As previously stated, the processing devices 7, 9 may include suction inlets integrated into the casing of the treatment device. Such suction inlets integrated into the casing can also be connected to the main collector 32 via pipes, in particular secondary pipes 34, and then form part of the suction inlets 36 of the suction system 30.

[0067] In order to efficiently and economically manage the different suction requirements of the scutching plant 1, without increasing the flow rate of the main collector 32, the suction system 30 includes control means 38 configured to control and modify the suction flow rate circulating in one or more corresponding suction outlets 36 mounted downstream of the control means 38.

[0068] Figure 5 illustrates an example of a control means 38, in the form of a damper. The control means 38 comprises a body 39 with, in particular, a closing flap 40 configured to close the fluid flow between the main manifold 32, for example via a secondary line 34, and the suction inlet(s) 36 mounted downstream of said control means 38. The flap 40 makes it possible, in particular, to stop, totally or partially depending on the geometry of the flap 40, the suction flow downstream of the control means 38. The flap 40 is actuated, for example, by means of an actuator, for example a cylinder 42. The cylinder 42 can, in particular, be controlled by the control means 24.

[0069] Furthermore, the control means 38 may also include a sensor enabling the determination of the open or closed position of the shutter 40, and transmitting this information to a remote means, in particular to the control means 24. The control means 24 can thus receive the data provided by the sensor(s) related to the position of the closing shutters 40 of the different control means.

[0070] In [Fig. 5], the closing flap 40 is not completely opaque but, on the contrary, includes an open portion 41. This portion 41 ensures that, regardless of the position of the flap 40 in the control means 38, a minimum suction flow rate is maintained in the suction inlet(s) 36 mounted downstream of said control means 38. Such a control means 38 is thus particularly advantageous for controlling the flow rate supplying the suction inlets 36 of the treatment devices 7 with a closing cover. Indeed, in the closed state, the closing flap 40 maintains a reduced suction flow rate, thereby creating a negative pressure within the enclosure of the treatment devices 7 with their corresponding closing covers, which retains the dust within said enclosure of the corresponding treatment devices 7.

[0071] Similarly, the treatment devices 9 without a closing hood can also include suction mouths 36 controlled by a regulating means 38 with a flap 40 having an open portion 41, in order to maintain a non-zero suction flow rate, even when the corresponding treatment device 9 is stopped.

[0072] Alternatively, it is also possible to provide a control means 38 with a solid flap 40 configured to completely stop the suction flow from the suction outlets mounted downstream, when it is in the closed position.

[0073] As can be seen in [Fig. 1], a control means 38 can be provided to control the suction flow rate of a single suction inlet, or to control the suction flow rate of several suction inlets mounted downstream. Thus, and as shown in [Fig. 1], the suction inlets 36 of the preparation means 8, the unwinding means 10, and the feeding table 12 are all regulated by a single control means 38, visible in [Fig. 3] above the opener 14.

[0074] Conversely, in the example illustrated in the figures, the various suction inlets of the opener 14, the thresher 16, the connecting table 18, the divider 20, and the crushers 22 are all individually regulated by an associated control means 38. However, it is also possible to provide a control means 38 to regulate several suction inlets of one or more of the aforementioned processing devices 7 with a closing hood.

[0075] The control means 24 is thus configured to control the various regulation means 38 in order to obtain the appropriate suction flow rates according to the zones and the operating mode of the scutching installation 1.

[0076] Thus, during normal operation of the scutching plant 1, the control means 24 actuates the regulating means 38 to obtain a significant, or even maximum, suction at the suction inlets 36 of the processing devices 9, which lack a closing cover. For such regulating means 38, the flap 40 can, for example, be actuated to be fully open. A suction flow rate of between 6,000 and 16,000 m³ / h, or even more, can then be obtained at said suction inlets 36.

[0077] At the same time, the control means 24 actuates the regulating means 38 so as to obtain reduced, or possibly zero, suction at the suction inlets 36 of the treatment devices 7 with closing cover. For such regulating means 38, the flap 40 can, for example, be actuated so as to be completely closed if it includes an open portion 41. A suction flow rate at said suction inlets 36 of between 1,000 and 5,000 m³ / h, or even more, can then be obtained, the flow rates being variable depending on the number of treatment devices and the desired level of negative pressure.

[0078] We then obtain a scutching installation 1 in the process of processing plant stems, with a significant suction at the level of the open processing devices 9 where the operators P intervene, and a reduced suction at the level of the closed processing devices 7 to maintain a depression.

[0079] In the event of a stoppage of the scutching installation 1, for example in the event of a temporary stoppage of the conveyors 29, the control means 24 may leave the regulating means 38 in the same configuration, or close, completely or partially, the regulating means 38 of the suction outlets 36 of the processing devices 9 without a closing cover so as to reduce, totally or partially, the suction flow rates during the stoppage of the scutching installation 1.

[0080] It also happens that a shutdown of the scutching plant 1 is necessitated by a malfunction of one of the processing devices 7 with a closing cover. For example, in the event of a blockage at one of the processing devices 7, it is sometimes necessary to open the closing cover of said processing device in order to resolve the blockage. In this case, the control means 24 receives a signal from the sensor connected to the closing cover, indicating that it is open. The control means 24 is then configured to stop, if this is not already the case, the scutching plant 1 totally or partially, for example by stopping the conveyor(s) 29 at said processing device 7 and upstream.The control means 24 is also configured to control the regulation means 38 of suction inlets 36 positioned at the level of the open closing cover, in order to open the flap 40 and allow a significant, or even maximum, suction flow rate to be obtained for the duration that the closing cover is open. A suction flow rate of between 6,000 and 16,000 m³ / h, or even more, can then be obtained at said suction inlets 36, which makes it possible to protect the operators P working on the jamming and also to extract the dust that may be released during the handling of the jammed rods or fibers.

[0081] To prevent an increase in the total suction flow rate when the control means 38 corresponding to the treatment device 7 is opened with the closing cover open, the control means 24 is also configured to control the control means 38 of suction inlets 36 positioned at treatment devices 9 without a closing cover, in order to close their flap 40, either fully or partially. This can result in a suction flow rate at said suction inlets 36 that is significantly lower than the normal operating flow rate, or even zero. Closing these control means 38 reduces the suction flow rate at the devices that are stopped, and recovers suction flow to increase the flow rate applied to the treatment device 7 with the closing cover open.

[0082] The coordination of the commands of the different means of regulation 38 therefore makes it possible to obtain the desired suction at the level of the areas where it is needed, without requiring an increase in the total suction capacities of the suction system.

[0083] Thus, thanks to the scutching plant according to the present invention, it becomes possible to improve dust extraction and reduce operator exposure to said dust, without increasing energy consumption related to extraction. By adapting the operation of the extraction system to the operating mode of the scutching plant, the present invention makes it possible to optimize extraction capacity for use in areas where it is needed. Operators working on or near the plant are thus better protected, regardless of their activity on the scutching plant, including handling or routine work.

Claims

Claims

1. Scutching installation (1) for the treatment of plant fibers, in particular flax or hemp, comprising: - several devices (7, 9) for treating said plant fibers mounted between an inlet (2) and an outlet (4) of said installation, one or more (7) of said devices comprising a closing hood and one or more (9) of said devices being without a closing hood, - a system (30) for suctioning the dust emitted during the treatment of said plant fibers, the suction system comprising several suction inlets (36) and being configured to circulate suction flows through said suction inlets, at least one suction inlet being intended to suck up the dust emitted at said one or more devices (7) comprising a closing hood and at least one suction inlet being intended to suck up the dust emitted at said one or more devices (9) without a closing hood,characterized in that the suction system (30) also comprises one or more flow rate regulating means (38), for example one or more registers, configured to regulate the flow rate sucked in by one or more suction inlets (36) at said device(s) (9) without a closing cover and at said device(s) (7) comprising a closing cover, and, in that the suction system (30) also comprises a control means (24) for said one or more flow rate regulating means (38), the control means (24) being configured to control said one or more regulating means (38) to decrease the suction flow rate of the mouth at a device (9) without a closing hood when said device (9) without a closing hood is stopped, and to increase the suction flow rate of the mouth at a device (7) with a closing hood when the closing hood of said device (7) comprising a closing hood is open.

2. Scutching installation (1) according to the preceding claim, in which the control means (24) is configured to control said regulating means (38) to reduce the suction flow rate of the mouth at the device (9) without a closing hood and to increase the suction flow rate of the mouth at the level of the device (7) with closing cover, when the device (9) without closing cover is stopped and the closing cover of said device (7) comprising a closing cover is open.

3. Scutching installation (1) according to the preceding claim, in which, when the device (9) without a closing hood is stopped and the closing hood of said device (7) comprising a closing hood is open, the control means (24) is configured to control said regulating means (38) so that a part of the flow rate removed from the suction mouth located at the device (9) without a closing hood is added to the flow rate of the suction mouth located at the device (7) comprising a closing hood.

4. Scutching installation (1) according to any one of the preceding claims, comprising one or more conveyors (29) configured to transport the plant fibers from the inlet to the outlet of the installation, passing through the different processing devices (7, 9), and in which a device (9) without a closing hood is stopped when the conveyor (29) present at said device (9) is stopped, or in which the closing hood of a device (7) comprising a closing hood is only open when the conveyor (29) present at said device (7) comprising a hood is stopped.

5. Scutching installation (1) according to any one of the preceding claims, in which the suction system (30) comprises a main collector (32) to which the different suction outlets (36) are connected, possibly by means of regulation means (38).

6. Scutching installation (1) according to any one of the preceding claims, in which each suction mouth (36) located at a device (7) comprising a closing hood comprises a regulating means (38) and / or in which the suction system comprises a regulating means (38) common to several suction mouths (36) located at one or more devices (7) comprising a closing hood.

7. Scutching installation (1) according to any one of the preceding claims, in which each suction mouth (36) located at a device (9) without a closing hood comprises a regulation means (38) and / or in which the suction system comprises a common regulating means (38) for several suction mouths (36) located at one or more devices (9) without a closing cover.

8. Scutching installation (1) according to any one of the preceding claims, in which, when the installation is in operation, the suction system (30) is configured to apply a suction flow rate to the devices (9) without a closing hood, and to apply a reduced suction flow rate to the devices (7) comprising a closing hood.

9. Method for controlling a suction system (30) of a scutching installation (1) for the treatment of plant fibers, said installation comprising several treatment devices (7, 9) of said plant fibers mounted between an inlet and an outlet of said installation, one or more (7) of said devices comprising a closing hood and one or more (9) of said devices being without a closing hood, in which suction flow rates are circulated to suck up the dust emitted at said device(s) (9) without a closing hood, and possibly at said device(s) (7) comprising a closing hood, when the installation is in operation, and in which the reduction, for example by controlling one or more regulating means (38),the suction flow rate at a device (9) without a closing hood when said device (9) without a closing hood is stopped, and the suction flow rate at a device (7) with a closing hood is increased, for example by controlling one or more regulating means (38), when the closing hood of said device (7) comprising a closing hood is open.,

10. Control method according to the preceding claim, in which the suction flow rate at the device (9) without a closing hood is reduced, for example by controlling one or more regulating means (38), to increase, for example by controlling one or more regulating means, the suction flow rate at the device (7) with a closing hood, when the device (9) without a closing hood is stopped and the closing hood of said device (7) comprising a closing hood is open.

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