Cut-off device with asymmetric foil or blade

Abstract

The present invention relates to a shut-off device (1) designed to close the orifice (21) of a fluid supply nozzle, the device comprising a rotor (3) having at least one blade (4) supported by a shaft, the blade having a rotation axis (5) parallel to the axis (22) of the nozzle, the blade alternately closing and opening the orifice of the nozzle during rotation. The blade includes a surface (6) for closing the orifice (21), the surface being formed by the edge of the blade that first moves forward of the nozzle when closing the nozzle, and an opening surface (7) corresponding to the edge of the blade opposite to the edge forming the closing surface. The blade (4) has an asymmetrical design.

Description

Technical Field

[0001] This invention relates particularly to the field of separating components from a medium, preferably a fluid medium, especially an incompressible fluid, or alternatively a solid or gaseous medium.

[0002] The present invention relates more particularly to an apparatus intended for use in the field of processing cellulose fibers or other fibers, and more particularly in the field of recycling waste paper, in particular to separate cellulose fibers of a certain three-dimensional size from contaminants of a larger size when screening pulp by means of a screen or grid with holes or slits.

[0003] More generally, the invention can be implemented in any technical field, wherein fluid is processed through a device, particularly a screening device, resulting in a pressure loss between the upstream and downstream portions of the device. Background Technology

[0004] Therefore, it is well known that separation devices, especially in the field of recycling paper, paperboard, etc., include enclosed pressurized housings equipped with perforated cylindrical grids, called screens, for separating different elements that constitute a fluid medium according to their size.

[0005] The housing is equipped with an inlet pipe (inlet) for the fluid mixture to be screened upstream of the screen, an outlet pipe for discharging impurities and contaminants that have not passed through the screen (reject stream) downstream of the screen, and an outlet pipe for discharging the mixture after impurities have been removed (accept stream)

[0006] In the context of paper recycling, recycled paper is first mixed with water, typically in a pulper, to suspend the cellulose fibers. After mixing and obtaining pulp containing these fibers and unwanted elements, it is desirable to screen out only the cellulose fibers and remove the unwanted components. These unwanted components may include metals, plastics, or mineral materials such as staples, ink, or glue particles.

[0007] Therefore, in this case, the fluid medium processed by the separation device is a slurry mixture containing unwanted components that are desired to be separated from the cellulose fibers to be recycled, for subsequent manufacturing of writing paper, newsprint, toilet paper, packaging paper, etc.

[0008] Cellulose fibers pass through the perforations of the screen, while contaminants are retained on the upstream side of the screen.

[0009] The difficulty of this operation lies in the fact that, in order to obtain the best screening performance, the perforations of the screen are very fine, generally around 150μm, and there is a risk of clogging.

[0010] In addition, there is a trend to use higher concentration slurries to reduce equipment size, but this increases the risk of clogging.

[0011] The risk of clogging also depends on the perforation size, the type of screen, the type of fluid mixture of the components to be separated, the pressure upstream of the screen, and the pressure downstream of the screen.

[0012] It's understandable that screen clogging is problematic because it prevents the separation of cellulose fibers from taking place under optimal conditions.

[0013] In fact, the accumulation and clogging of fluid mixture components on the screen can prevent its selective separation function. If this accumulation persists, there is a risk of completely blocking the flow of the mixture through the screen.

[0014] To avoid or reduce this clogging, one solution could be to increase the size of the screen perforations. However, this solution is suboptimal because it compromises the quality of the differential separation operation by size.

[0015] In addition, a traditional solution to avoid this blockage is to place a rotor equipped with a deblocking rotating foil or blades in the separation device.

[0016] The rotor is typically arranged close to the screen, usually upstream of it, and rotates at a peripheral speed of 10 to 25 m / s.

[0017] At this rotational speed, each foil or blade will experience localized pressure pulsations due to changes in the hydraulic flow along the blade.

[0018] This pulsation creates localized low pressure between the blades and the screen, causing a localized backflow of slurry from downstream to upstream as it passes through the screen.

[0019] Therefore, the components that clog the screen are broken up and discharged through the repellent pipe, and the perforations are unblocked each time the blade passes through.

[0020] However, solutions with rotors featuring unblocking blades or foils have several drawbacks.

[0021] In particular, the number and design of the foils or blades are fixed in terms of air gap size and profile shape. Therefore, the frequency, intensity, and duration of unblocking can only be changed by affecting the rotor speed.

[0022] While changing the rotor speed, especially its acceleration, can alter the unblocking frequency and intensity, it actually has the disadvantage of generating harmful excessive energy consumption and reducing separation selectivity.

[0023] At the industrial level, reduced separation selectivity results in additional costs and faster wear, especially at the blades.

[0024] International application number WO2017 / 125692, published under the same company name as this patent application, describes an apparatus for separating components of a fluid medium, which takes the form of a closed housing equipped with separating elements, particularly a screen, and connected to at least one pipe.

[0025] In the design of this prior art device, the pressure pulsation used to unblock the screen is generated by a shut-off device located on a pipe connected to the housing, which is capable of completely or partially closing the pipe.

[0026] More specifically, the shut-off device includes at least one element fixed to a movable support. The element is designed to completely or partially close or not close the conduit, depending on its position and geometry relative to the conduit.

[0027] Such shut-off devices can consist of gate valves, ball valves, globe valves, valves with deformable shut-off devices, or butterfly valves.

[0028] However, these valves are relatively large in size and height, so they require a large amount of space for installation.

[0029] Furthermore, the valve's sealing surfaces experience relative wear during opening and closing, even at high temperatures.

[0030] Gate valves typically have two sealing surfaces, which makes them more difficult to handle, grind, and maintain.

[0031] The valve also has the disadvantage of long opening and closing times, so this solution is not suitable for the intended application, especially since the valve will suffer from extremely rapid wear in these applications.

[0032] In another preferred example, described in more detail in this prior art document, the shut-off device consists of a rotating disc. The disc comprises a support frame and at least one flap for closing the pipe, the disc serving as a support for the flap.

[0033] Examples of such cut-off devices are shown in the accompanying drawings. Figure 1 It is presented in an informational manner.

[0034] The continuous rotation of the disc causes the continuous rotation of the closing flap, which gradually closes the pipe. During this continuous movement, the flap is movable during the so-called activation phase, which causes movement of the flap support device and the flap itself.

[0035] In fact, the document proposes to activate the cutoff device by means of a control device that is adapted to cyclically activate and deactivate the cutoff device at a given frequency, each cycle including an activation phase and an inactivation phase.

[0036] Therefore, during its activation phase, the shut-off device can gradually change the pipe closure rate between a minimum and a maximum value, so as to adjust the pressure pulsation according to the operating conditions of the screening and unblocking device to improve screen unblocking. During its deactivation phase, the shut-off device is stationary.

[0037] Although the solution can generate pressure pulses to unblock screens or limit buildup, it still has drawbacks.

[0038] In particular, the pulse effect can be further improved to optimize screen declogging.

[0039] On the one hand, generating and controlling the cycle, including the continuously movable activation phase of the shut-off device and the inactive phase where the shut-off device cannot move, is complex and requires precise adjustment through appropriate commands and control devices. In particular, prolonged pipe closure forces fluid to flow through the screen, which may accelerate the formation of fiber pads on the screen, thereby clogging it.

[0040] Furthermore, with the shut-off device rotating at a constant speed, the pipe is unlikely to be blocked for a sufficiently long time to allow the pressure in the loop to rise sufficiently, thus achieving effective unblocking.

[0041] Finally, in addition to inevitably leading to high energy consumption, excessively high rotational speeds may cause the pipes to close too quickly, potentially resulting in water hammer and damage to the equipment.

[0042] Other prior art documents describe rotor devices of various designs, in particular documents DE19807503, US4953595 and DE102012023078.

[0043] Documents DE19807503 and DE102012023078 disclose devices for closing openings in the form of a rotating disk, the disk itself having one or more openings. These devices are not intended for applications involving the separation of media components, nor do they attempt to generate pulsations in the flow.

[0044] The apparatus described in document US4953595 relates to a mud pulse valve, comprising a body, a stator, and a rotor rotatably arranged within the body and capable of rotating relative to the stator. The stator has a plurality of stator holes, and the rotor has a plurality of rotor holes. Each stator hole corresponds to a rotor hole, and the stator holes are arranged within the stator in a geometric configuration similar to that of the rotor holes arranged and configured within the rotor. Therefore, a predetermined rotation of the rotor relative to the stator causes the stator holes and rotor holes to open and close simultaneously. The stator holes and rotor holes are open when at least partially aligned with each other, and closed when no portion of the stator hole overlaps with any portion of the rotor hole.

[0045] However, these devices are not suitable for the intended application in this application and cannot overcome the disadvantages of the other separation devices equipped with various cut-off devices to unblock the screen.

[0046] The present invention aims to overcome at least partially the shortcomings of existing technology devices. Summary of the Invention

[0047] In the inventive steps, it has been envisioned that the design of the shut-off device be modified so that the device is easy to implement under operating conditions, the pipe is not shut off too suddenly, and sufficient shut-off duration is ensured to allow for opening as quickly as possible, generating a sudden pressure drop in the system to improve the unclogging effect of the screen.

[0048] Therefore, the present invention relates to a shut-off device aimed at closing the orifice of a fluid supply nozzle, particularly intended for integration into a device for separating fluid medium components, the shut-off device comprising a rotor having at least one foil or blade in a plate-like shape, the at least one blade being supported by a shaft whose axis of rotation is parallel to the axis of the supply nozzle, the at least one blade alternately closing and opening the orifice of the supply nozzle during rotation to generate unblocking pulsations in the circuit.

[0049] The at least one blade includes a face for closing the orifice and a face for opening the latter, the closing face being formed by the edge of the blade that first moves in front of the nozzle when the nozzle is closed, and the opening face corresponding to the edge of the blade opposite to the first edge forming the closing face.

[0050] The cutting-off device of the present invention is characterized in that the at least one blade has an asymmetrical design, the closing surface of which is a straight line or a curved shape, the straight line or a straight line passing through the center of gravity of the curved shape and the closing surface of the blade at the inner end of the rotor forming an angle α with a radial straight line passing through the inner end, and the opening surface of which is a straight line or a curved shape, the straight line or a straight line passing through the center of gravity of the curved shape and the opening surface of the blade at the inner end of the rotor forming an angle β with a radial straight line passing through the inner end, wherein α is greater than β, thereby making the opening speed of the supply nozzle orifice greater than the closing speed of the same orifice.

[0051] Advantageously, the at least one plate-shaped blade corresponds to an annular portion, which is positioned externally or internally relative to an inner circle whose center corresponds to the rotation axis of the rotor shaft.

[0052] Very preferably, the closing surface of the at least one blade is composed of a straight line tangent to the inner circle of the rotor, such that the angle α is equal to 90°.

[0053] In different embodiments, the closing surface of the at least one blade has a convex shape.

[0054] The closing surface can then advantageously be composed of a circular arc, the center of which is located on the blade side.

[0055] The closing surface of at least one blade can also form a curve tangent to the inner circle of the rotor, with the center of its radius of curvature located on the blade side.

[0056] Regarding the opening surface, the latter may specifically consist of radial straight lines whose axis passes through the rotor's rotation axis, thereby making the angle β equal to 0.

[0057] In another alternative embodiment, the opening surface may also be concave.

[0058] Very preferably, the opening surface has a circular or arc-shaped cut, and when it has a circular cut, the cut advantageously has the size of a fluid supply nozzle orifice so that the opening surface closely coincides with the orifice when it passes in front of the orifice.

[0059] The cutting device may advantageously have 1 to 5 blades.

[0060] The present invention also relates to an apparatus for separating components of a fluid medium having a useful component to be recovered and a contaminant to be removed, the separating apparatus comprising an element for separating the components, such as a screen, in a housing, capable of allowing the useful component to pass downstream of the screen while retaining the contaminant upstream of the screen, the housing being connected upstream of the separating apparatus, taking into account the circulation direction of the fluid medium, to a conduit for supplying the fluid medium to the housing and to a conduit for discharging the repellent stream, the housing being also connected downstream of the separating apparatus to an outlet conduit for the stream, the separating apparatus then integrating at least one cut-off device according to the invention and positioned on at least one conduit connected to the housing. Attached Figure Description

[0061] Other objects and advantages of the invention will become apparent in the following description, with reference to embodiments given as indicative and non-limiting examples.

[0062] This description will be more easily understood with reference to the accompanying drawings, in which:

[0063] Figure 1 A schematic diagram of a prior art device for shutting off a pipe, viewed from above, is shown.

[0064] Figure 2 It shows that it can be used Figure 1 Or a schematic front view of three rotor geometries in any other cutting device. Figure 2 The left side shows a rotor with five blades or foils, the middle side shows a rotor with two blades, and the right side shows a rotor with three blades.

[0065] Figure 3 This is a schematic front view of a first embodiment of the cutting device according to the present invention.

[0066] Figure 4 This is a schematic front view of a second embodiment of the cutting device according to the present invention.

[0067] Figure 5 This is a schematic front view of a third embodiment of the cutting device according to the present invention.

[0068] Figure 6 This is a schematic front view of a fourth embodiment of the cutting device according to the present invention.

[0069] Figure 7 These are schematic front views of three other embodiments of the cutting device according to the present invention.

[0070] Figure 8 The schematic diagram illustrates the cutting device according to the invention, corresponding to Figure 6 The device shown is intended to be integrated into a device for separating fluid media components.

[0071] Figure 9 The graph shows the change in pressure (P, in bars) inside the screening device over time (in seconds), measured at different rotational speeds of the new cutting device of the present invention, namely 6.7 rpm, 5.4 rpm, and 4 rpm.

[0072] Figure 10 The graph shows the change in pressure (in bars) inside the screening device over time (in seconds), measured in the flow pipeline, using the novel cut-off device of the present invention (gray curve in the figure) on one hand, and using a device with... Figure 2 The prior art double-blade truncation device shown in the middle has a similar geometry (black curve in the figure), with the two rotors rotating at approximately 7 rpm.

[0073] Figure 11 The graph shows the change in pressure (in bars) inside the screening device over time (in seconds), measured in the flow pipeline, using the novel cut-off device of the present invention (dark gray curve in the figure) on one hand, and using a device with... Figure 2 The prior art double-blade cutting device (light gray curve in the figure) with a similar geometric shape is shown in the middle. The two rotors rotate at different speeds, namely 6.7 rpm for the new rotor and 2 rpm for the known double-blade device. Detailed Implementation

[0074] Refer to the attached diagram. Figure 3 As shown in the following figures, the present invention therefore relates to a shut-off device 1, which is intended to close the orifice 21 of the fluid supply nozzle 2.

[0075] The cutting device 1 according to the invention can be particularly, but not limitedly, integrated into a device for separating fluid medium components.

[0076] It should be noted that the medium for separating the components can also be composed of a solid medium or a gaseous medium.

[0077] This cutting device 1 can be advantageously used in the fields of filtration, screening, grading, and concentration, especially for cellulose fibers, textile fibers, or any other type of fiber.

[0078] The cutting device 1 of the present invention can therefore be advantageously integrated into a separation device, particularly in the paper industry, especially for recycling waste paper and / or paperboard.

[0079] Paper, which is made of cellulose fibers, must be screened to remove unwanted components, such as glue, staples, ink, various plastics, metals or minerals, as mentioned above, in order to be used in the manufacture of recycled paper.

[0080] It should be noted that the cutting device 1 according to the invention can also be used in the textile industry, and is also used to recycle textile fibers, thereby separating various types of contaminants (especially metals or plastics) that may be present in the textile fibers, and recycling these fibers for the manufacture of recycled textiles.

[0081] The cutting device 1 of the present invention can also be incorporated into the design of a separation device intended for use in water treatment facilities to separate polluting or non-polluting waste, particularly waste that is large in size or volume.

[0082] In practice, the water to be treated may include mineral materials such as rocks, soil particles, or any other unwanted elements, such as plastic materials, which need to be removed before further treatment can proceed.

[0083] The separation device that can be integrated with the cutting device 1 of the present invention and the various components of its design and composition will be described in more detail below.

[0084] Now returning to the design of the cutting device 1 of the present invention, the device is more specifically composed of a rotor 3, which has at least one foil 4 or blade 4 in a plate-like shape on one hand, and a shaft 5 of which is parallel to the axis 22 of the supply nozzle 2 on the other hand.

[0085] Therefore, the at least one blade 4 corresponds to the annular portion 41, which is preferably positioned on the outside, but may also be positioned on the inside, with the center of the inner circle 31 corresponding to the rotation axis 5 of the rotor 3.

[0086] The shaft is rotated by a drive device, which drives at least one blade 4 to rotate in the direction of rotation shown by the arrow in the figure, which is counterclockwise in this example. When the blade 4 rotates, it alternately closes and opens the orifice 21 of the fluid supply nozzle 2.

[0087] The cyclic closing and subsequent opening of the orifice 21 creates a pulse in the device circuit where the cut-off device 1 is located, for unblocking the separation device (e.g., a screen type) also integrated into the device.

[0088] Therefore, the cut-off device 1 consists of a surface 6 for closing the orifice 21 of the fluid supply nozzle 2 and a surface 7 for opening the orifice 21.

[0089] The closing surface 6 is formed by the edge of the blade 4 that moves first to the front of the orifice 21 when the nozzle 2 is closed.

[0090] As for the opening surface 7, it corresponds to the edge of the blade 4 that is opposite to the first edge that forms the closing surface 6.

[0091] It should be noted that, although the attached diagram... Figures 3 to 7 A specific and preferred embodiment of the cutting device 1 of the present invention is shown, which includes a single blade 4, but in other embodiments, the cutting device 1 may have multiple blades 4.

[0092] Therefore, depending on the size of the cutting device 1, the length of the blade 4 and the intended application, the device 1 may specifically have one or more blades 4, which are advantageously identical but may be different, and are preferably regularly distributed on the periphery of the inner circle 31 of the rotor 3.

[0093] In the following description, although reference may be made to a cutting device 1 having a single blade 4, the described features apply to the cutting device 1, whether it has one or more blades 4.

[0094] According to a specific feature of the cutting device 1 of the present invention, the at least one blade 4 is designed to be asymmetrical.

[0095] In this asymmetric design, more specifically, the surface 6 of the orifice 21 used to close the fluid supply nozzle 2 can be composed of straight lines, as shown in the attached figure. Figure 3 , Figure 5 , Figure 6 as well as Figure 7 The various configurations shown are illustrated.

[0096] However, the closing surface 6 can also be composed of a curved shape, as shown in the attached figure. Figure 4 As shown.

[0097] In the first case, when the closing surface 6 of the blade 4 is composed of a straight line, the latter forms an angle α with the radial straight line d1, which passes through the end 61 of the closing surface 6 located within the rotor 3 of the cutting device 1.

[0098] In the second case, when the closing surface 6 of blade 4 has a curved shape, it is a straight line d. Bf Forming an angle α, the straight line d Bf On the one hand, the center of gravity B forms the curved shape of the closed surface 6. f On the other hand, through the end 61 of the closing surface 6 located inside the rotor 3, the straight line d Bf An angle α is formed with the radial line d1, which passes through the end 61 of the closing surface 6 located within the rotor 3 of the cutting device 1.

[0099] Now, regarding the opening surface 7 of the orifice 21 of the fluid supply nozzle 2, it can also be made in a straight or curved shape.

[0100] The case where the opening surface 7 is a straight line can be seen in the attached figure. Figure 3 , Figure 4 , Figure 5 And attached diagrams Figure 7 In the different configurations of the cutting device 1 shown, the curved opening surface 7 (semi-circular in this example) is shown in the accompanying drawings. Figure 6 and Figure 8 middle.

[0101] In the first case, when the opening surface 7 of the blade 4 is composed of a straight line, the latter forms an angle β with the radial straight line d2, which passes through the end 71 of the opening surface 7 located within the rotor 3 of the cutting device 1.

[0102] When the opening surface 7 of blade 4 is composed of a curved shape, the straight line d Bo On the one hand, the center of gravity B forms the curved shape of the opening surface 7. o On the other hand, the end 71 of the opening surface located inside the rotor 3 forms an angle β with the radial line d2, which passes through the end 71 of the opening surface 7 located inside the rotor 3 of the cutting device 1.

[0103] All configurations of the closing surface 6 and opening surface 7 of the blade 4 described above can be combined, that is, both opening and closing surfaces of the blade 4 can be straight lines, or both can be curves, or one can be a straight line and the other can be a curve.

[0104] However, regardless of the configuration chosen, the following characteristics must be observed: the angle α at the closed surface is greater than the angle β at the open surface, so that the opening speed of the orifice 21 of the fluid supply nozzle 2 is greater than the closing speed of the orifice 21.

[0105] In fact, by adhering to the relationship α>β, the blade 4 requires a larger angular displacement to close the orifice 21 of the nozzle 2, while the operation required to open the same orifice 21 is smaller, thus enabling the orifice 21 to be opened more quickly.

[0106] Now refer to the attached diagram. Figure 2 as well as Figure 1 It illustrates different rotor designs known in the prior art that can be applied to applications similar to those described in this application. It should be noted that the blades of these truncation devices all have a symmetrical design.

[0107] Furthermore, both the closing and opening surfaces are generally radial relative to the rotor's axis of rotation, as shown in the attached figure. Figure 2 The image on the left is particularly noteworthy.

[0108] Therefore, when a rotor equipped with such blades rotates at a constant speed, the speed at which the blades close the orifice as they pass in front of it is equal to the speed at which the orifice subsequently reopens.

[0109] Conversely, by means of the asymmetric design of this cutting device 1 and its blades 4, the constant rotational speed of the rotor 3 can, on the one hand, ensure that the speed at which the blades 4 close the orifice 21 of the nozzle 2 is lower than the opening speed of the same orifice 21, while on the other hand, allow the orifice 21 to be closed for a sufficiently long time.

[0110] Now, obtaining a sufficient shut-off duration is necessary to achieve sufficiently high pressure within the circuit, device, or facility equipped with such shut-off device 1, and restarting the fluid supply nozzle 2 as soon as possible will create a sudden pressure drop within the circuit in which it is located.

[0111] Therefore, when the orifice 21 is rapidly reopened, the instantaneous flow rate of fluid through the supply nozzle 2 will be temporarily greater, thereby generating a high flow rate upstream of the nozzle 2, for example along a screen-type or other type of separation device, and thus generating a reduced pressure, which is located, for example, upstream of the cut-off device 1 (considering the fluid path).

[0112] The resulting reduced pressure will allow for effective unclogging of the screen under the aforementioned conditions.

[0113] In a specific and preferred embodiment of the closing surface 6 of blade 4, as shown in the figure. Figure 3 , Figure 5 and Figure 6 As shown, the closing surface 6 is composed of straight lines tangent to the inner circle 31 of the rotor 3, such that the angle α formed by the surface 6 and the radial straight line d1 is equal to 90°.

[0114] However, in other configurations, as shown in the attached figure... Figure 7As shown, the closing surface 6 is also composed of straight lines, but these lines are not tangent to the inner circle 31 of the rotor 3. Therefore, it should be understood that the angle α can also have a value less than 90°.

[0115] Now refer to the attached diagram. Figure 4 It shows another embodiment of the cutting device 1, wherein the closing surface 6 of the blade 4 is composed of a curve, which is preferably convex and advantageously composed of circular arcs, the center of which is located on the side of the blade 4, or forms a curve tangent to the inner circle 31 of the rotor 3, the center of which is located on the side of the blade 4.

[0116] Therefore, in the above configuration, the radial line d1 and the line d Bf The angle α between the lines has a value greater than 90°, and the line d Bf On the one hand, the center of gravity B forms the curved shape of the closed surface 6. f On the other hand, the end 61 of the closed surface 6 located inside the rotor 3 is closed.

[0117] Regarding the opening surface 7, it may consist of radial straight lines whose axes pass through the rotor's rotation axis 5, such that angle β equals 0. This possibility is specifically illustrated in the accompanying drawings. Figure 3 and Figure 4 And attached diagrams Figure 7 The left side represents the middle.

[0118] However, as shown in the attached figure Figure 5 Or attached diagram Figure 7 As shown in the middle and right sides, the opening surface 7 of the blade 4 can also be composed of a straight line forming an angle β>0 with the radial straight line d2, which passes through the rotation axis 5 of the rotor 3.

[0119] The opening surface 7 of the blade 4 of the cutting device 1 of the present invention may also be concave, as shown in the attached figure. Figure 6 This particularly preferred embodiment variation can be seen in the text.

[0120] Therefore, more specifically, in this figure, the opening face 7 has a circular cutout in a particularly favored design, which is a semi-circular cutout in this example, but it should be remembered that the opening face 7 of the blade can also be composed of an arc.

[0121] Advantageously, when the opening face 7 is composed of a circular portion, the latter has the size of the orifice 21 of the fluid supply nozzle 2 so that the opening face 7 closely overlaps with the orifice 21 as it passes in front of the orifice 21, thereby allowing the latter to open as quickly as possible.

[0122] Under these specific conditions, an opening speed has been achieved, enabling the orifice 21 to open in less than 0.1 seconds.

[0123] The cutting device 1, which features the characteristics of the present invention, is of particular interest.

[0124] This enables the provision of a robust and particularly simple system, as the rotor 3 is driven at a constant speed, while the asymmetry of the opening surface 7 and the closing surface 6 allows the nozzle 2 to open at a speed greater than its closing speed, and the duration of the nozzle's closure is controlled by the geometry of the rotor 3 (particularly the geometry of the blade 4) and the drive speed of the rotor 3.

[0125] Therefore, the cutting device 1 of the present invention allows for periodic and continuous operation in a facility that will be described in more detail below, using a motor with a constant rotational speed.

[0126] The signal to open the orifice 21 of the supply nozzle 2 can be customized according to the geometry of the blade 4 of the rotor 3 and the rotational speed of the latter's drive motor.

[0127] While maintaining a constant rotational speed, the device of the present invention allows the generation of an asymmetric signal, causing the opening time of the orifice 21 of the nozzle 2 to be different from its closing time, and as noted above, the opening speed (greater in this example) of the orifice 21 to be different from its closing speed.

[0128] The cutting device 1 of the present invention also allows for an increase in the number of cycles per minute without changing the rotor speed by adding one or more blades 4 to the periphery of the rotor 3. Thus, for example, two cycles per revolution can be obtained by means of two blades 4.

[0129] It should be noted that, with the aid of the device 1 of the present invention, the duration of the cycle (or loop) can be between 60s and 2s.

[0130] Furthermore, it has been estimated that the cutoff device 1 can operate for more than 21,000,000 cycles without compromising its performance.

[0131] It should also be recalled here that the cut-off device 1 is capable of managing heterogeneous flows, i.e., liquids, solids or gases.

[0132] Therefore, in a particular application of the cutting device 1 of the present invention, the latter constitutes part of an apparatus or more comprehensive facility for separating components of a fluid medium having a useful component to be recovered and a contaminant to be removed, the useful component being, in particular, cellulose or textile fibers, which are mixed with water and contaminants in a slurry or fiber suspension.

[0133] Such a separation device includes elements in the housing for separating the components, such as a screen, which allows the useful components (in this case, cellulose or textile fibers) to pass downstream of the screen while the contaminants are retained upstream of the screen.

[0134] This type of housing is traditionally connected upstream of the separation unit (considering the circulation direction of the fluid medium (fiber suspension)) to a pipe for supplying the fluid medium to the housing.

[0135] The housing is also connected to a conduit for discharging the repellent stream, which corresponds to the components (contaminants and fibers) of the fiber suspension that did not pass through the screen, while the separation device is connected downstream to an outlet conduit for discharging the screened fibers.

[0136] In this invention, the separation device or facility is characterized in that it integrates at least one cutting-off device 1 as described above, which is positioned on at least one pipe connected to the housing.

[0137] Therefore, both the flow-in and flow-out pipelines can be equipped with the cutting device 1 according to the invention, or a single device 1 can be integrated into the facility, preferably located on the flow-out pipeline, but this is not limiting, the single cutting device 1 can also be located on the flow-in pipeline.

[0138] Attached Figure Figure 8 A portion of the shut-off device 1 is schematically shown, in one of its preferred designs, intended to be connected to a conduit for separating the components of the medium, with the inflow of the fluid medium indicated by the arrows in the figure.

[0139] To illustrate the effect and benefits of the cutting device 1 of the present invention when integrated into a facility for separating fluid medium components, a comparative test was specifically conducted with a known prior art rotor, and the accompanying drawings were used. Figure 6 and Figure 8 The cut-off device 1 shown is a preferred design.

[0140] These tests will now be conducted with reference to the attached diagram. Figure 9 , Figure 10 and Figure 11 Describe it.

[0141] As a preliminary note, it should be pointed out that previous tests (the results of which will not be repeated here) have been able to demonstrate that, assuming the use of geometry known in the prior art (i.e., such as...), Figure 2 In the case of a double-blade or double-foil rotor (as shown), an increase in rotor speed will result in a decrease in the peak pressure measured in the flow pipeline of the facility used to separate the mixture.

[0142] This reduction in pressure peak is due to the rotor geometry not allowing the pipe to be closed for a sufficient period of time for the pressure to rise adequately.

[0143] The cutting device 1 of the present invention overcomes this problem.

[0144] In fact, from the attached diagram Figure 9As can be seen, the figure shows the pressure (in bar) over time measured at different rotational speeds (4 rpm, 5.4 rpm, and 6.7 rpm) in the component separation facility. It can be seen that increasing the speed of rotor 3 does not decrease the peak pressure value, or the decrease is negligible.

[0145] Therefore, it can be inferred that the new rotor design allows for a reduction in the rotational speed of the screen rotor, which can be specifically positioned inside the screen formed by the cylindrical grid. In fact, for existing dual-foil rotors, the rotational speed of the screen rotor has already been reduced by 30%, meaning that the screen will become clogged below this speed.

[0146] With the tested cutting device 1 of the present invention, the rotational speed of the screen rotor can be reduced by 40% to 55% under very stable conditions (no blockage), and blockage only occurs when the rotational speed of the screen rotor is lower.

[0147] When using the cutting device 1 of the present invention, this reduction in the rotational speed of the screen rotor inevitably leads to a reduction in facility energy consumption, thereby reducing costs in the long term.

[0148] Furthermore, from the attached diagram Figure 11 As can be seen from the chart, with the help of this cut-off device 1, the closing duration of the orifice 21 of the supply nozzle 2 is long enough to achieve the balanced pressure of the three speeds tested.

[0149] In fact, for all three speeds of the rotor 3 tested, even at the highest speed of 6.7 rpm, the pressure peak plateaued, indicating that equilibrium pressure had been reached. This pressure then dropped abruptly when the blade's unique opening surface design allowed for rapid opening.

[0150] Therefore, it can be inferred that the rotational speed of the rotor 3 of the cutting device 1 of the present invention can be further increased, and / or the opening surface of the rotor can be increased.

[0151] Now refer to the attached diagram. Figure 10 This figure allows for comparison of peak pressures obtained in the flow path of the facility, illustrating the use of the cutting device 1 of the present invention in the facility or using a prior art double-blade or double-foil rotor (whose geometry is similar to the figure). Figure 2 As shown in the middle section, the change of the peak pressure (in bar) measured inside the sieve over time (in seconds).

[0152] For these tests, the speed of the screen rotor was 12 m / s when a double-blade rotor was used in the facility, and the speed of the screen rotor was 10 m / s when the cutting device 1 of the present invention was used in the facility.

[0153] Attached Figure Figure 10The charts allow us to illustrate that the presence of a dual-blade rotor in the facility generates a pressure peak, but does not reach the plateau.

[0154] At a comparable rotational speed, the peak pressure generated by the cutting-off device 1 of the present invention is significantly greater than the peak pressure generated by the rotor of the prior art. As a result, when rapid opening occurs, the pressure drops significantly and rapidly, effectively unclogging the screen.

[0155] As for the attached diagram Figure 11 The chart makes it possible to compare the peak pressure generated by the cutting device 1 of the present invention when the rotor 3 rotates at a higher speed (6.7 rpm) with the peak pressure generated by the prior art dual-blade rotor (which maintains a rotation speed of only 2 rpm).

[0156] Similarly, the pressure peak generated by the rotor in the prior art has not reached the plateau, and therefore has not reached the equilibrium pressure, while the cutting device 1 of the present invention has reached the equilibrium pressure even when operating at a significantly higher speed.

Claims

1. A shut-off device (1) designed to close the orifice (21) of a fluid supply nozzle (2), the shut-off device (1) comprising a rotor (3) having at least one blade (4) in a plate-like shape, the at least one blade (4) being supported by a shaft whose rotation axis (5) is parallel to the axis (22) of the supply nozzle (2), the at least one blade (4) alternately closing and opening the orifice (21) of the supply nozzle (2) during rotation to generate unblocking pulsations in the circuit, the at least one blade (4) comprising a means for closing the orifice (21). The shut-off device (1) is characterized by a closing surface (6) of the nozzle (21) and an opening surface (7) for opening the latter, the closing surface (6) being formed by the edge of the blade (4) that first moves in front of the nozzle (2) when the nozzle (2) is closed, and the opening surface (7) corresponding to the edge of the blade (4) opposite to the first edge forming the closing surface (6). The at least one blade (4) has an asymmetrical design, and its closing surface (6) is a straight line or a curve, the straight line or the curve passing through the centroid (B) of the curve. f The straight line (d) of the closed surface (6) of the blade (4) at the inner end (61) of the rotor (3) and the blade (4) is perpendicular to the blade (4). Bf ), and forms an angle α with the radial straight line (d1) passing through the inner end (61), while the opening surface (7) is a straight line or a curve, the straight line or the curve passing through the centroid (B) of the curve. o The straight line (d) of the opening face (7) of the blade (4) at the inner end (71) of the rotor. Bo ), and form an angle β with the radial straight line (d2) through the inner end (71), where α is greater than β, so that the opening speed of the orifice (21) of the supply nozzle (2) is greater than the closing speed of the same orifice (21).

2. The cutting device (1) according to claim 1, characterized in that, At least one blade (4) in the form of a plate (41) corresponds to an annular portion, which is positioned outside or inside relative to an inner circle (31), the center of which corresponds to the rotation axis (5) of the rotor (3).

3. The cutting device (1) according to claim 2, characterized in that, The closing surface (6) of the at least one blade (4) is composed of a straight line tangent to the inner circle (31) of the rotor (3), such that the angle α is equal to 90°.

4. The cutting device (1) according to claim 2, characterized in that, The closing surface (6) of at least one blade (4) is convex.

5. The cutting device (1) according to the preceding claim, characterized in that, The closing surface (6) is composed of an arc, and the center of its radius of curvature is located on the side of the blade (4).

6. The cutting device (1) according to claim 4, characterized in that, The closing surface (6) of at least one blade (4) forms a curve tangent to the inner circle (31) of the rotor (3), with the center of its radius of curvature located on the side of the blade (4).

7. The cutting device (1) according to claim 1, characterized in that, The opening surface (7) is a radial straight line, and its axis passes through the rotation axis (5) of the rotor (3), so that the angle β is equal to 0.

8. The cutting device (1) according to claim 1, characterized in that, The opening surface (7) is concave.

9. The cutting device (1) according to claim 8, characterized in that, The opening surface (7) has a circular portion or an arc-shaped cut.

10. The cutting device (1) according to claim 9, characterized in that, The circular portion of the opening surface (7) has the size of the orifice (21) of the fluid supply nozzle (2) so that the opening surface (7) closely overlaps with the orifice (21) when it passes in front of the orifice (21).

11. The cutting device (1) according to claim 1, characterized in that, The closing surface (6) of the at least one blade (4) is composed of a straight line tangent to the inner circle (31) of the rotor (3) such that the angle α is equal to 90°, and the opening surface (7) has an arc-shaped cutout with the size of the orifice (21) of the fluid supply nozzle (2) so that the opening surface (7) closely coincides with the orifice (21) when it passes in front of the orifice (21).

12. The cutting device (1) according to claim 1, characterized in that, It has 1 to 5 blades (4).

13. A separation device for separating components of a fluid medium, having a useful component to be recovered and a contaminant to be removed, the separation device including an element in a housing for separating the components, capable of allowing the useful component to pass downstream of the element while retaining the contaminant upstream of the element, the housing being connected upstream of the separation device, taking into account the circulation direction of the fluid medium, to a conduit for supplying the fluid medium to the housing and to a conduit for discharging a repellent stream, the housing also being connected downstream of the separation device to an outlet conduit for a stream, the separation device being characterized in that it integrates at least one cut-off device (1) according to any one of the preceding claims and is positioned on at least one conduit connected to the housing.

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