FR3000906A1 - CONICAL CONVEYOR TANK MIXER - Google Patents

Abstract

Mixer comprising: - a frame (1) - a conical tank (10), closed at the top, - a draining device (13) at the bottom comprising a lower opening (130) of the tank and a shutter (131) adapted to move from a closed position to a drain position, - mixing tools (20), internal to the conical vessel (10), comprising a helical screw (21) extending along the height of the vessel and at less a scraper (22, 22 ') intended to scrape the conical wall of the tank (10), according to the invention, it comprises: - articulation means between said conical tank (10) and the frame (1), adapted to allow rotation of the conical vessel about its axis, - driving means adapted to actuate in rotation the conical vessel (10), and wherein the mixing tools (20) are arranged in fixed positions relative to on the frame (1).

Description

The invention relates to a rotary bowl mixer, and more particularly to a conical bowl mixer for any type of concrete. The mixer according to the invention can also find a particular application for the mixing of foundry sand.

In the field of concrete preparation, it is known to use fixed-tank mixers, inside which tools, driven in rotation, are used to mix the products. Classically known cylindrical tank mixers, for example EP 1 842 583 A1, whose tools are driven in a complex rotational movement by a drive mechanism of the planetary type. The state of the art of concrete mixers also knows conical tank mixers, fixed. This conical tank is associated with stirring means, arranged axially in the tank, the tank comprising an exhaust hatch in the lower part for discharging the prepared concrete. The stirring means generally consist of a worm associated with scrapers and / or kneading blades to allow homogenization of the concrete mixture during its preparation. During the preparation of the concrete, the materials (cement, sand, gravel) are introduced in a precise quantity into the tank to obtain the desired concrete or mortar and water is gradually added thereto once the stirring means have been put in place. running, the worm to raise the materials at the bottom of the tank and mix them with water and scrapers to prevent a build-up of concrete on the wall of the tank. EP 1 121 193 discloses, for example, such a kneader comprising a fixed conical bowl in which are arranged scrapers arranged near the wall of the tank and an endless screw arranged in the center of the tank for mix the materials. A drive mechanism, comprising two engines, allows to drive in rotation the worm, and the scrapers along an axis of rotation coaxial with that of the conical vessel. According to this document, the direction of rotation of the scrapers can be alternated in order to improve the quality of the mixing.

However, such a mixer involves a complex drive mechanism, in particular by the arrangement of tools, generally in the center of the tank and their rotation system within the fixed vessel, which does not allow, according to the findings of the inventor, to introduce the materials in the center of the tank but only at an edge. According to the findings of the inventor, and the fact that the materials are introduced only at the edge of the tank, the materials are not all properly dispersed at the beginning of mixing, which requires to extend the mixing time in order to obtain the desired concrete quality.

In addition, because of the arrangement of the drive mechanism, there are also difficulties for maintenance and cleaning of the mixers after use, access to the tank being relatively difficult for operators. The object of the present invention is to overcome all or part of the aforementioned drawbacks by providing a conical rotating bowl mixer. More particularly, an object of the present invention is to provide a mixer for mixing products in a reduced time. Another object of the present invention is to provide such a mixer which is simple to maintain and clean.

Another object of the present invention is to provide such a mixer whose direction of rotation and the rotation frequency of the tools can be adjusted. Another object of the present invention is to provide such a mixer which is inexpensive and simple to implement.

These objectives, as well as others which will appear more clearly later, are achieved according to the invention with the aid of a mixer comprising: - a frame, - a conical tank, closed at the top, - a device for draining in the lower part comprising a lower opening of the tank and a shutter capable of passing from a closed position to a draining position, - mixing tools, internal to the conical tank, comprising a helical screw extending over the height of the tank and at least one scraper for scraping the conical wall of the tank. According to the invention, the mixer comprises means of articulation between said conical vessel and the frame, able to allow rotation of the conical vessel about its axis, as well as drive means able to actuate in rotation the conical vessel. , the mixing tools being arranged in fixed positions relative to the frame. Advantageously, the mixer may have a feed opening of material in the center of the upper part of the tank. In order to allow such an opening in the axis of the tank, the mixing tools are not arranged on the axis of the tank, but arranged around the latter. According to one embodiment, said mixing tools, internal to the tank, integral with the frame, comprise, in addition to the helical screw and said at least one scraper, a rapid mixing tool. According to a particularly simple approach, the helical screw, the rapid mixing tool and the at least one scraper are angularly distributed about the axis of rotation of the conical vessel. According to an advantageous aspect of the invention, said at least one scraper comprises a lower scraper and an upper scraper, angularly offset relative to one another about the axis of the tank, each of which is arranged partially over the height of the scraper. conical tank, able to scrape the wall of the conical tank, respectively on the lower part and the upper part of said conical tank.

According to one embodiment, said at least one scraper, where appropriate said lower scraper can scrape, in addition to the conical wall of the tank, the wall of the shutter. According to one embodiment, the mixer has means for pivoting between the shutter and its support, said pivoting means being of axis of rotation coaxial with the axis of rotation of the conical vessel, in the closed position of the shutter so that the shutter rotates integrally with the tank in the closed position of the shutter. According to one embodiment, a jack makes it possible to move the shutter from the closed position to a detached position following a translation of direction parallel to the axis of the conical tank, the shutter / jack assembly being integral with an arm articulated on the frame to completely retract said shutter to said empty position. According to one embodiment, the draining device comprises a ring, removably attached to the conical tank, at the bottom opening, constituting a seat for the shutter in the closed position and sealing between the shutter and the conical tank. According to one embodiment, the inner wall of the tank is covered by a ceramic shield, said ring for removing the dead space between the shield of the conical tank and the shutter in the closed position. According to one embodiment, the connection between the shutter and its support comprises elastomeric elements so as to allow disengagement of the shutter. According to one embodiment, the mixer comprises liquid supply means in the tank arranged in such a way as to introduce the liquids at the level of said rapid mixing tool. According to an advantageous aspect of the invention, the mixer comprises means for alternating the direction of rotation of the tank. According to a particular aspect of the invention, said axis of rotation of the vessel is inclined relative to the vertical, preferably such that a generatrix of the vessel is substantially vertical. Other features and advantages of the invention will appear more clearly on reading the following description of a particular embodiment of the invention, given as a simple illustrative and nonlimiting example, and the appended drawings, among which: FIG. 1 is a sectional view of a rotating bowl mixer according to one embodiment of the invention; FIG. 2 is a front view of the mixer illustrated in FIG. 1; FIG. 3 is a front view of the mixer of FIG. 1; Figure 4 is a side view of the mixer of Figure 1; Fig. 5 is a detail view of the material feed opening of the rotating bowl mixer of Fig. 1; FIGS. 6 and 7 are bottom and top views of a rotating bowl mixer according to the invention; - Figure 8 is a bottom view illustrating the emptying device of a rotating bowl mixer in emptying position of the tank; FIG. 9 is a detailed view illustrating the emptying device of the mixer of FIG. 1; - Figure 10 is a partial view of the tank, illustrating the arrangement of the scrapers; FIG. 11 is a sectional detail view illustrating the emptying device of the mixer of FIG. 1. As previously mentioned, the general principle of the invention is therefore based on the use of a rotary bowl mixer, suitable for to mix a mixture of different materials, powdery and liquid, and for example for the manufacture of concrete. To achieve this objective, a rotating bowl mixer capable of kneading various materials, comprises a frame 1, a conical tank 10, supported by the frame 1, closed at the top, and a drainage device 13 at the bottom comprising a lower opening. 130 of the tank and a shutter 131 adapted to move from a closed position to a drain position. Mixing tools 20, internal to the conical bowl 10, comprise a helicoidal screw 21 extending over the height of the tank and at least one scraper 22, 22 'intended to scrape the wall of the conical tank 10.

According to the invention, the mixer comprises: articulation means 3 between said conical tank 10 and the frame 1, able to allow rotation of the conical tank 10 about its axis, driving means 4 capable of rotating the conical bowl 10, and in which the mixing tools 20 are arranged at fixed positions relative to the frame 1. The rotating bowl mixer shown in Figure 1 thus comprises a mixing tank 10, conical, in which material mixing is performed, and internal mixing tools 20.

The conical shaped mixing tank 10 comprises an upper part 11 having an upper opening, the cone being directed downwards. The mixing tank 10 is rotatably disposed relative to the frame 1, by means of said hinge means 3. These hinge means may comprise guide elements such as bearings, interposed between the tank and the frame adapted to resume the load of the tank and to allow rotation relative to the frame. The drive means may comprise, according to one embodiment, a ring gear 40 fixed to said conical bowl 10 and a geared motor 41, integral with the frame 1, meshing with said ring gear 41 so as to transmit the movement of rotation of the motor to the ring gear 41. According to one embodiment, the drive means 4 can enable the tapered vessel to be rotated alternately, in a first direction of rotation and in a second opposite direction of rotation, by intervals of time. The upper opening of the vessel 10 may be closed by means of a cover 9 having one or more material feed openings. The mixing tank 10 also comprises the emptying device 13 in the lower part, at the end of the cone formed by the lower part. According to a non-illustrated embodiment of the invention, a gutter may be arranged upstream of the emptying device so as to evacuate the concrete formed to a receptacle. The internal mixing tools 20 comprise, in particular, the helical screw 21 comprising a rotation shaft around which a helical blade is disposed and is intended to stir and up the materials in the conical tank 10, at least in a first direction of rotation of the screw. Thus, by rotating the screw in a first direction of rotation, the mixture around the screw is moved upwards in the mixing tank 10. Conversely, when the screw rotates in the opposite second direction, the mixture is forced to go down. According to one embodiment, the mixer can thus have means for alternating the direction of rotation of the helical screw 21. Preferably, the helical screw 21 is used during mixing, most of the time, to raise the materials. Inverting the rotation of the screw, alternately, however, allows to remove the agglomerates of materials that can accumulate on the underside of the helical screw. It should be noted that the helical screw 21 may be replaced, according to a non-illustrated embodiment, by a rotor having distinct blades arranged on the height and the circumference and inclined so as to allow the materials to be raised, in a manner similar to said helical screw. This rotor is compatible with the other tools, and in particular the scraper or scrapers 22, 22 'and the rapid mixing tool 23 which is described below. The internal mixing tools 20 also comprise said at least one scraper 22, 22 'for scraping the wall of the tank 10. Said at least scraper 22, 22' is preferably rigidly secured to the frame 1. According to a particular embodiment of the invention, the internal mixing tools 20 comprise two scrapers 22, 22 ', namely a lower scraper 22 and an upper scraper 22. The lower scraper 22 and the upper scraper 22' are angularly offset relative to each other. the other around the axis of the conical vessel 10, in particular at an angle less than 45 °. The lower scraper 22 and the upper scraper 22 'are each partially arranged on the height of the conical tank 10, able to scrape the conical tank wall 10, respectively on the lower part 12 and the upper part 11 of said conical tank 10. More particularly, the lower scraper 22 for scraping the lower part 12 of the vessel, that is to say the generator of the formed cone, extends on the lower part of the height of the cone, and the scraper 22 'upper intended to scrape the upper part of the tank scrapes the upper portion of the cone, and extends over the upper part of the height of the cone. In the case of larger mixers, the scrapers may be of number greater than two, for example three staggered scrapers, on the one hand, depending on the height of the tank to scrape respectively the tank on the lower part, an intermediate part. , and an upper part, and on the other hand angularly around the axis of the tank. Optionally, the lower scraper 22 can also scrape the wall of the shutter 131, in the closed position of the shutter 131. In addition to said helical screw 21 and said at least one scraper 22, the internal mixing tools 20 may also include a rapid mixing tool 23 comprising a rotation shaft 25 at the end of which is disposed a mixing end 24 for homogenizing the mixture of materials in the tank. By rapid mixing tool is meant a tool intended to rotate at a speed of rotation greater than the rotational speed of the helical screw 21. The motor / gear motor 26 of this tool can allow rotational speeds greater than 100 rpm, preferably greater than 150 rpm.

The helical screw may be provided to rotate at a speed between 50 and 100 rpm to provide an average linear speed of movement of the mixture of between 1m / s and 2m / s (i.e. 1.5m / s). Advantageously, said helical screw 21, the rapid mixing tool 23 and said at least one scraper 22 are angularly distributed about the axis of rotation of the conical tank 10. During mixing, at least for a given period of time, the conical tank 10 is rotated in the helical screw direction 21, rapid mixing tool 23 and scrapers 22, 22 'and, simultaneously, the helical screw 21 is rotated so as to raise the materials. Thus, during a rotation of the tank, the material successively undergoes the action of the helical screw 21 which raises the material, the action of the rapid mixing tool 23 on which falls the material raised by the screw, and the action of or scrapers 22,22 'which clean the tank, downstream of the rapid mixing tool. According to a particular embodiment of the invention, the mixer comprises liquid supply means 25 in the tank preferably arranged in such a way as to introduce the liquids directly at the level of the quick-mixing tool 23. Such a device Provision will be made for better introduction of liquids to solids. For example, liquids may be introduced into the upper part of the rotational shaft of rapid mixing tool 23 within the hollow shaft. and then exit at the other end of the rotation shaft 25 at the quick-mixing tool. In another example, the liquids may flow along the rotational shaft of the rapid mixing tool on its outer surface. The internal mixing tools 20, more particularly the helical screw 21 and the rapid mixing tool 23, can be driven by means of geared motors, separate and independent, respectively, at the end of the rotation shaft of each tool, at the level of the upper part of the tank. The internal mixing tools can thus rotate at different speeds of rotation depending on the quality and quantity of materials to be mixed. As can be seen in FIG. 2, the motors can be mounted on an inverted U-shaped structure 8 belonging to the frame 1, the structure 8 overlapping the conical tank 10. Optionally, this structure 8 can also accommodate the engine intended to to rotate the conical vessel 10.

As can be seen in Figures 2 and 3, the cover 9 closing the upper portion 11 of the conical vessel 10 can be retractable, at least in part and can move from an open position to a closed position. Additionally or alternatively, the cover 9 may also have a feed opening 7 of materials, visible in Figures 4 and 5, in the center of the upper part of the conical vessel. According to this embodiment, the arrangement of the internal mixing tools 20 thus allows the presence of said feed opening 7, in the axis of the tank.

According to a particular embodiment of the invention, illustrated without limitation in Figures 6, 8 and 9, the emptying device 13 comprises said lower emptying opening 130, and the shutter 131 adapted to close the lower emptying opening 130 This shutter 131 is articulated about a coaxial axis A to the axis of rotation of the tank, in the closed position, so as to rotate integrally with the tank 10 in the closed position of the shutter, the shutter 131 is then driven by the tank. The pivoting means between the shutter 131 and its support may comprise a ball bearing 135 arranged around the axis so as to allow the shutter 131 to rotate when it is secured to the conical tank 10, pressed against the latter. According to a particular embodiment of the invention, a jack 132 or other actuator makes it possible to move the shutter 131 from the closed position to a detached position following a translation of direction parallel to the axis of the conical vessel. 20.

Once the shutter 131 in the unstuck position, the shutter / jack assembly, integral with an arm 134 can be moved in rotation by means of a hinge 137 between the arm 134 and the frame 1, in particular of axis parallel to the axis of the tank outside the field of the opening 130, and to the position of emptying the shutter.

The rotation of the arm 134 following the articulation 137 is preferably actuated by an actuator 138.

The shutter 131 may have a circular rib 139 with a breakage function, avoiding run-out on the mechanism (jack 132) for raising or lowering the shutter 131. This mechanism, as well as the pivoting means can be protected at the inside of a flexible sleeve 140, joining the shutter 131 and its support. According to an advantageous embodiment, the connection between the shutter 131 and its support (in particular the arm 134) comprises elastomeric elements 133 so as to allow disengagement of the shutter 131.

According to the embodiment of Figure 9, these elastomeric elements 133 are provided in particular between the rod and the piston of the cylinder 132. These elastomeric elements 133 allow the shutter 131 to close the tank and to ensure the seal during the rotation, even in the event of slight misalignment between the axis of rotation of the conical tank 10 and the axis of rotation of the shutter 131, or else to close the conical tank 10 even when the opening 130 is not closed. completely clean. In general, the conical tank may be in particular metal, the inner wall preferably covered with a ceramic shield. Advantageously, the device the emptying device 13 may comprise, at the level of the lower opening 130 of the conical tank 10, a ring 136, removably attached to the conical tank 10, in particular by means of screws 137. This ring 136 can be easily replaced in case of wear. This ring 136 constitutes a seat for the shutter 131 in the closed position and seals between the shutter 131 and the conical tank 10. Advantageously, this ring 136 preferably eliminates the dead space between the shield 15 of the conical tank and the shutter. The seal between the shutter 131 and this ring 136 can be improved thanks to a circular seal 138, carried either by the shutter 131 or by said ring 136.

As illustrated in FIG. 11, this ring 136 may have an L-shaped section, the horizontal flange having holes for fasteners (ie screws) for securing the ring 136 to the conical bowl 10, the interior of the vertical wing L of the ring 136 being intended to engage with the shutter, in the form of a disc, by interlocking. The upper end of this vertical wing is of thickness substantially equal to the thickness of the ceramic shield 15 so as to cover the lower edge of the shield by removing the dead space. According to a non-illustrated embodiment, the axis of rotation of the conical vessel 10 may be inclined, preferably such that a generatrix of the conical vessel 10 is substantially vertical. Such an arrangement of the conical vessel 10 in particular makes it easier to empty the concrete once it is finished. A mixer as described above is especially used for mixing concrete and can also be used for mixing foundry sand.

Naturally other embodiments could have been envisaged without departing from the scope of the invention as defined by the claims below.

NOMENCLATURE 1 Frame, 3 Articulation means, 4 Drive means, 7 Feed opening, 8 U-shaped structure, 9 Cover, Conical bowl, 10 11 Upper part of the tank, 12 Bottom part of the tank, 13 Device Drain, 14 Platinum, 15. Ceramic Shield, 20 Mixing Tools, 21 Twist Screw, 22, 22 'Scrapers, 23 Quick Mixing Tool, 24 Mixing End (Quick Mixing Tool), 25 Rotating Shaft (Cleaning Tool) Quick Mix), 26 Motor (Quick Mixing Tool), 130 Lower Drain Hole, 131 Retractable Cover, 132 Cylinder, 133 Elastomer Connection, 134 Arms, 135 Ball Bearing, 136 Bushing (Seating Seat), 137 Screws, 138. Seal, 139 circular rib (breakage),

Claims (14)

REVENDICATIONS1. Mixer comprising: - a frame (1) - a conical tank (10), closed at the top, - a draining device (13) at the bottom comprising a lower opening (130) of the tank and a shutter (131) adapted to move from a closed position to a drain position, - mixing tools (20), internal to the conical vessel (10), comprising a helical screw (21) extending along the height of the vessel and at at least one scraper (22, 22 ') for scraping the conical wall of the vessel (10), characterized in that it comprises: - articulation means between said conical vessel (10) and the frame (1), adapted to allow rotation of the conical vessel about its axis, - driving means adapted to actuate in rotation the conical vessel (10), and wherein the mixing tools (20) are arranged in fixed positions relative to on the frame (1). 2. Mixer according to claim 1, wherein said mixing tools (20), internal to the conical bowl (10), integral with the frame (1), comprise, in addition to the helical screw (21) and said at least one scraper ( 22), a rapid mixing tool (23). 3. Mixer according to claim 2, wherein the helical screw (21), the rapid mixing tool (23) and said at least one scraper (22,22 ') are angularly distributed around the axis of the conical vessel (10). 4. Mixer according to one of claims 1 to 3 wherein said at least one scraper (22, 22 ') comprises a lower scraper (22) and an upper scraper (22'), angularly offset relative to one another. other around the axis of the tank, each arranged partially on the height of the conical tank (10), able to scrape the conical tank wall (10), respectively on the lower part (12) and the upper part (11). ) of said conical tank (10). 5. Mixer according to one of claims 1 to 4, wherein said at least one scraper (22,22 '), where appropriate said lower scraper (22') can scrape, besides the conical wall of the tank, the wall of the shutter (131). 6. Mixer according to one of claims 1 to 5, having a material feed opening (7) in the center of the upper part of the conical vessel (10). 7. Mixer according to one of claims 1 to 6, having pivoting means between the shutter (131) and its support said pivoting means being of rotation axis coaxial with the axis of rotation of the conical vessel ( 10), in the closing position of the shutter so that the shutter (131) rotates integrally with the tank in the closed position of the shutter (131). 8. Mixer according to claim 7, wherein a jack (132) can move the shutter (131) from the closed position to a detached position in a directional translation parallel to the axis of the conical vessel (20). the shutter / jack assembly being secured to an arm (134) articulated on the frame to completely retract said shutter to the emptying position. The mixer according to claim 7 or 8, wherein the draining device (13) comprises a ring (136), removably attached to the tapered vessel, at the bottom opening (130), providing a seat for the shutter (131) in the closed position and sealing between the shutter (131) and the conical vessel (10). 10. Mixer according to claim 9, wherein the inner wall of the tank is covered by a ceramic shield (15), said ring (136) for eliminating the dead space between the shield (15) of the conical tank (10). ) and the shutter (131) in the closed position. 11. Mixer according to one of claims 7 to 10, wherein the connection between the shutter and its support comprises elastomeric elements (133) so as to allow misalignment of the shutter (131). 12. Mixer according to one of claims 1 to 11 comprising liquid supply means in the tank arranged to introduce liquids directly at said rapid mixing tool (23). 13. Mixer according to one of claims 1 to 12, wherein the mixer comprises means for alternating the direction of rotation of the vessel. Mixer according to one of claims 1 to 13, wherein said axis of rotation of the vessel is inclined with respect to the vertical, preferably so that a generatrix of the conical vessel (10) is substantially vertical.