LOADING OF SOLID PARTICLES INTO A VESSEL

Abstract

A device (20) for distribution of solid particles (22) for loading a vessel with solid particles, comprising a solid particles feed hopper (21), a rotating member and a drive member for driving in rotation said rotating member about a rotation axis, and a set of at least one deflector element (25, 25, 25) carried by said rotating member and erected, or adapted to be erected, on rotation of the shaft, relative to the rotation axis, in which device the feed hopper defines a set of at least one opening (29) conformed in an asymmetric manner relative to the rotation axis, defining at most one plane of symmetry passing through the rotation axis.

Claims

1. A device for distribution of solid particles when loading a vessel with said particles, comprising: a solid particle feed hopper defining a set of at least one opening for evacuation of the particles from the hopper by gravity, a rotating member and a drive member coupled to said rotating member to drive said rotating member in rotation about a rotation axis having a direction with a component in the direction of the gravity vector, downstream of the set of at least one opening of the feed hopper a set of at least one deflector element carried by said rotating member erected relative to the rotation axis or adapted to be erected relative to the rotation axis, characterized in that the set of at least one opening in the feed hopper is conformed in an asymmetric manner relative to the rotation axis, defining at most one plane of symmetry passing through the rotation axis.

2. The distribution device of claim 1, in which the set of at least one deflector element is such that when erected relative to the rotation axis the projections of said set in a plane normal to the rotation axis of the rotating member have an asymmetric distribution around said rotation axis, defining at most one plane of symmetry passing through the rotation axis.

3. The distribution device of claim 1, in which the drive member is such that the rotating member to which it is coupled effects an oscillating movement with the rotation direction reversed at the ends of an angular range extended over at most 350.

4. The distribution device of claim 1, in which at least one deflector element is rigid.

5. The distribution device of claim 1, in which at least one deflector element defines with the rotating member an articulated connection so that this deflector element is able to be set from a position for introduction into the vessel to a position erected relative to the rotation axis independently of the rotation of the rotating member.

6. The distribution device of claim 5, further comprising at least one linkage member cooperating with at least one deflector element so as to be able to cause that deflector element to move from the position for introduction into the vessel to the position erected relative to the rotation axis when a rod of the linkage member is actuated.

7. The distribution device of claim 1, in which the drive member comprises a motor controlled to effect a continuous rotation movement and elements for conversion of the continuous rotation movement of the motor into a movement with variations of angular speed over an angular range of 360 or less.

8. The distribution device of claim 1, comprising a plurality of deflector elements, preferably of different sizes.

9. The distribution device of claim 1, in which the deflector elements are distributed over an angular range from more than 5 to less than 320, preferably less than 280, more preferably less than 180 and still better less than 120.

10. The distribution device of claim 1, in which the rotation axis is different from the axis of the hopper.

11. The distribution device of claim 1, in which the set of at least one opening of the feed hopper comprises a plurality of openings of different sizes, in particular openings of greater size on one side of the hopper than on the other side.

12. A method for installation of the solid particle distribution device of claim 1 in a vessel having an orifice in its upper part, in which there are caused to pass through said orifice at least the rotating member and the set of at least one deflector element at an eccentric position relative to a central axis of the vessel.

13. An assembly comprising a vessel defining a central vertical axis and the distribution device of claim 1 installed in said vessel via an opening of said vessel defined in its upper part at an eccentric location relative to said central axis.

14. The assembly of claim 13 in which the vessel is a catalytic reaction reactor.

15. A method of loading solid particles into a vessel comprising a central vertical axis, comprising: a) the installation in the vessel of the distribution device via an opening of the vessel located in its upper part, preferably at a location eccentric relative to a central axis of the vessel; then b) driving in rotation the rotating member of said device; and c) loading particles by introducing them into the feed hopper of said device while the rotating member continues to rotate.

16. The method of claim 15, characterized in that the rotating member effects an oscillating movement with the rotation direction reversed at the ends of an angular range extending over 350 or less, preferably 330 or less, more preferably 320 or less, better 310 or less, and even better 270 or less.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0099] The invention will be better understood with reference to the figures, which show nonlimiting embodiments.

[0100] FIG. 1 represents diagrammatically an assembly comprising a reactor and one example of a prior art solid particle distribution device.

[0101] FIG. 2 is a diagrammatic view from below of one example of a prior art assembly when in motion.

[0102] FIG. 3 is a diagrammatic view from above of one example of an assembly in accordance with one embodiment when in motion.

[0103] FIG. 4 is a diagrammatic sectional view of one example of a solid particle distribution device in accordance with another embodiment when in motion.

[0104] FIG. 5 is a diagrammatic perspective view of a part of one example of a solid particle distribution device in accordance with another embodiment, when stopped or rotating at a low speed.

[0105] FIG. 6 is a sectional view in a vertical plane of a part of one example of an assembly in accordance with one embodiment of the invention.

[0106] FIG. 7A is a diagrammatic perspective view of a part of one example of a solid particle distribution device in accordance with another embodiment with the deflector elements in the position for introduction into the vessel.

[0107] FIG. 7B is a diagrammatic perspective view of a part of the example of a solid particle distribution device from FIG. 7A when stopped or rotating at a low speed.

[0108] FIG. 8 is a highly diagrammatic view of a part of one example of a solid particle distribution device in accordance with another embodiment, when stopped or rotating at a low speed.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0109] Identical references may be used from one figure to the other to designate identical or similar elements.

[0110] Referring to FIG. 1, a reactor 1 defines an opening 13, referred to as an orifice, for the passage in particular of a device 3 for distribution of solid particles 6, 7.

[0111] The distribution device 3 may for example be of the same type as that described in the document WO 2010/076522.

[0112] In the example represented the distribution device rests on a plate 4 of the reactor 1 on arms.

[0113] The device 3 further includes semi-rigid straps 9 for better distribution of the solid particles. These semi-rigid straps 9 are each fixed by one end to a shaft 31 extending along a vertical axis (D) through a hopper 5 for feeding solid particles 5.

[0114] This hopper may be connected to a store of solid particles, not shown, in a manner known in itself.

[0115] During loading solid particles flow through openings 8 defined at one end of the hopper, situated above the straps 9.

[0116] Also, the shaft 31 is driven in rotation by a motor, not represented, so that the straps extend away from the shaft at an angle.

[0117] Particles falling from the hopper 5 are liable to rebound on these straps and thus to be deviated from their trajectory. These somewhat random deviations can enable dense loading of solid particles.

[0118] The distribution device 3 enables loading of the reactor 1 with inert balls 6 and also with catalyst particles 7.

[0119] By products loaded into the reactor, or loading of the reactor, is meant solid particles distributed into the reactor by the distribution device, for example the beds 6, 7 from FIG. 1, the reagents and products in the chemical sense of the term, and/or otherwise.

[0120] Referring to FIG. 2, a solid particle distribution device of the type known from the prior art is represented installed in a reactor 1 via an opening 13 of that reactor.

[0121] This device comprises a hopper 5 crossed by a shaft 17 on its central axis.

[0122] This shaft 17 extends downwards beyond the hopper 5 and on an end part are mounted four identical straps distributed in a regular manner over the circumference of the shaft.

[0123] When as shown in FIG. 2 the shaft is driven in rotation the straps are erected relative to the shaft. The angular speed is constant at least over approximately ten revolutions, typically over relatively long time periods. The straps are therefore able to deviate a large quantity of solid particles, with no preferred direction because of the symmetry in the distribution of the blades and the absence of reversing of the rotation direction.

[0124] Referring to FIG. 3, there has been represented one example of a solid particle distribution device 20 in accordance with one embodiment when installed in a reactor 10 in accordance with a method in accordance with one embodiment of the invention.

[0125] This solid particle distribution device 20 comprises a hopper 21, for example 8 cm in diameter, received in an orifice 2 of the reactor, for example 10 or 12 centimeters in diameter.

[0126] The hopper 21 is crossed by a shaft 24 extending downwards beyond an opening 29 occupying the whole of the bottom of the cylindrical hopper 21 for the passage of solid particles (not represented) circulating in the hopper 21.

[0127] It can be seen that the shaft 24 and the hopper 21 are not concentric, the shaft 24 being eccentric relative to a central axis of symmetry of the hopper 21. Consequently the opening 29 is conformed in an asymmetric manner relative to this shaft 24 so that the flow rate of solid particles will be higher on one side of the shaft than on the other.

[0128] In this example eight straps 25, 25, 25 are mounted on this shaft 24.

[0129] In this example, each of these straps comprises an aluminum core (not represented) surrounded by a rubber sheath.

[0130] Each of the straps 25, 25, 25 is fixed by one end to the shaft 24 so as to form a pivot connection, the other end remaining free, so that the straps can be erected relative to the shaft when the latter is driven in motion.

[0131] Alternatively, the straps 25 being very short, they can be rigidly mounted on the shaft 24.

[0132] The set of straps is conformed so that their projections in a plane parallel to the plane of the sheet during a rotation movement are distributed in an asymmetric manner around the axis of the shaft 24, i.e. it is not possible to distinct planes of symmetry passing through this shaft.

[0133] In this embodiment the straps are distributed at 360.

[0134] In an embodiment that is not represented the straps are circumscribed in an angular range extending over almost 90 and there are no straps over the angular range symmetrical thereto relative to the rotation axis.

[0135] The shaft 24 is driven in an oscillating movement, changing rotation direction after a travel of 240 for example.

[0136] The shaft 24 is installed in an eccentric manner relative to a central axis of the reactor, thus enabling space to be freed up for installing other devices 30.

[0137] The shaft 24 is initially oriented so that the planes it crosses at zero speed are either side of the vertical plane passing through the central axis of the reactor and through the shaft, at similar or equal distances: accordingly, during the oscillating movement, this vertical plane is often crossed by at least one relatively long strap 25, 25, which favors deviation toward the center of the reactor and the part of the wall of the reactor farther from the device 20. Relatively dense loading of the reactor can therefore be achieved.

[0138] It may be noted that in this example not all the straps of the same length (in the radial direction, when in rapid motion), the straps 25 being shorter than the straps 25 and the straps 25 near the wall of the reactor being even shorter than the straps 25.

[0139] In the FIG. 4 embodiment there is only one deflector element 125, produced from a layer of very flexible material, of slightly or hardly circular shape, installed around the shaft 117 in the manner of an eccentric.

[0140] The area of this deflector element, when erected around the shaft or when flat, over a first angular sector 101 corresponding to the angle of 1, is much higher than the area of this deflector element over a second angle sector 102 symmetrical to the sector 101 relative to the axis of the shaft 117 (and corresponding to the angle 1 and therefore of equal value to 1).

[0141] By applying an oscillating movement and preferably by tipping the particles onto the angular sector 101 it is therefore possible to break up the isotropic nature of the deviation of the particles and to alleviate the lack of symmetry caused by an eccentric position relative to the central axis of a reactor.

[0142] In FIG. 5 embodiment the straps 225 are disposed at diverse heights and have different lengths.

[0143] In the case of rapid movement the projections of the straps in a plane (P) normal to the rotation axis corresponds to a larger area than in an angular sector tied to the shaft having an angle 1 than in the symmetrical angular sector extending over an angle 2=1.

[0144] There has been represented in FIG. 6 a top part of an assembly in accordance with one embodiment comprising a reactor, of which only a part 311 is shown, a solid particle distribution device and a thermocouple 318.

[0145] The thermocouple 318 is fastened to a cover 312 covering the upper opening of the reactor.

[0146] This cover 312 defines a passage into which may be introduced a hopper lower part 306 of small diameter fastened to an upper part 305 of greater diameter.

[0147] This passage may for example have a diameter of the order of ten centimeters, for 12 centimeters.

[0148] The reactor may have for example a diameter of 60 centimeters and define a volume of close to 5 cubic meters.

[0149] Thanks to this cover 312, leaks and damage caused by dust are prevented and moreover, in that it is no longer necessary to open the reactor, preparation times are reduced.

[0150] Passed through the hopper is a shaft 317 connected to an alternating movement motor 307 and to rigid plastic straps 325 mounted on and articulated to the shaft 317.

[0151] The hopper 305, 306 is installed offset relative to a central axis of the opening of the reactor.

[0152] These straps 325 are not distributed over 360 around the rotation axis of the shaft 317 but instead over a limited angular portion, for example of less than 60.

[0153] A distribution device is installed in the reactor so that the straps are oriented at least broadly speaking toward the center of the reactor.

[0154] The hopper 306 is filled with catalyst (not represented) that flows via openings not shown mostly above the straps 325.

[0155] The motor 307 is controlled by a microcontroller that is not represented programmed to import an oscillating movement to the shaft 317 fastened to the rotor of the motor 307.

[0156] There may be provided for example between 50 and 500 periods per second, for example 100 or 200 periods per second.

[0157] In the embodiment from FIGS. 7A and 7B the distribution device 417 comprises a hopper 418 defining a plurality of, here four, lateral openings 419.

[0158] In this example each opening 419 is equipped with a blocking flap 420 mounted on and sliding on vertical rails. The effective section of each opening 419 can therefore be adjusted so that the set of openings 419 can be distributed in an asymmetric manner over the periphery of the hopper so as to favor the evacuation of the particles contained in the hopper in certain directions.

[0159] Under these openings 418 rigid plastic deflector elements 425 are mounted on a rotating element 421.

[0160] That rotating element 421 cooperates via conversion means with no reference symbol with a shaft crossing the hopper positioned in a central manner relative to the hopper and driven in rotation by a motor that is not represented.

[0161] These conversion means, comprising in particular a roller, enable transformation of the continuous rotation movement of the shaft into an oscillating movement of the rotating element 421.

[0162] An articulation at the end of each deflector element 425 defines a pivot connection between that reflector element and the rotating element 421.

[0163] To be more precise, two flanges 427 facing one another are fastened by screws to the deflector element. These flanges 427 define orifices to receive a rod 426 passing through a bore defined in the rotating element 421.

[0164] Thanks to this pivot connection the deflector elements 425 are therefore able to pass from a position for introduction into the vessel, as shown in FIG. 7A, to a deployed position, as shown in FIG. 7B.

[0165] In this embodiment, this passage from one position to the other is effected by means of a linkage member 422. This member comprises a plurality of rods articulated to one another, including a central vertical rod 423 and radial rods 424. The radial rods 424 are articulated to the deflector elements 245 and the linkage member 422 is such that a vertical movement of the central rod 423 drives in movement the radial rods 424 and therefore the deflector elements 425, in the manner of an umbrella.

[0166] Thus the deflector elements installed in the vessel may be erected before starting the motor.

[0167] The influence of the rotation speed on the angle of the deflector elements can therefore be reduced, and possibly zero. The rotation speed can therefore affect the permeability to particles independently of this angle between the rotation axis and the longitudinal direction tied to a deflector element.

[0168] The linkage member may advantageously be conformed so that the angular position of at least one deflector element (for example all of the deflector elements or each deflector element individually) may be adjustable.

[0169] It has proven that this device, with its asymmetries, offers relatively high performance in terms of loading.

[0170] In fact, the Applicant has simulated in a relatively satisfactory manner the loading density as a function of a certain number of parameters, including the dimensions of the vessel, the rotation speed, the dimensions of the deflector elements, the size of the particles, the weight of the particles, the mass of all the particles loaded, etc. If such simulations are effected before tests carried out with a distribution device of the same type as that from FIG. 1, the experimental results agree with the results obtained by simulation.

[0171] A simulation and a test have been carried out using the distribution device from FIG. 7B, the simulation being effected in accordance with the known simulation method and with values of parameters (dimensions of the vessel), average length of the deflector elements, width of the deflector elements, etc.) corresponding to the actual test values. A loading density much greater than the simulated density is surprisingly achieved. The simulated and expected density was 1.462 ton per cubic meter, whereas the experiment resulted in a density of 1.505 ton per cubic meter, that is to say an increase of almost 15%, when the distribution device occupied an eccentric position in the vessel.

[0172] Referring to FIG. 8, there has been represented an example of the distribution device in accordance with another embodiment in which the deflector elements 525 are all the same length and are driven in a continuous rotation movement at constant speed while the hopper defines an opening 518 asymmetric relative to the rotation axis of the shaft 510. The grains of catalyst are therefore mostly discharged toward the center of the vessel, the deflector elements enabling relative homogeneity to be obtained.

[0173] It may be noted that the vessel 501 is closed at the top by a cover 502 defining a small number of offtakes, here two offtakes 503, 504. One offtake 503 corresponds to the passage of the distribution device while the other offtake 504 may correspond to the passage of a probe or other device.