FR2782705A1 - Extraction assembly for removing granular material from silo comprises first extractor and second extractor arranged beneath it and below base of silo. - Google Patents

Abstract

The extraction assembly has a primary extractor that uses an endless screw thread (21) driven in rotation that is parallel to the base of the silo. It drives material (5) towards an outlet (29) that is provided at the center of the silo. A secondary extractor (28) is provided below the primary extractor. This recovers, in a position in the base of the silo, the material extracted by the primary extractor.

Description

- * 1

TOGETHER FOR EXTRACTION

  OF PULVERULENT OR GRANULAR MATERIALS

  STOCKEES IN A SILO, AND SILO PROVIDED WITH SUCH A SET

  The present invention relates to an assembly for the extraction of pulverulent or granular materials stored in a silo, and also relates to

a silo provided with such an assembly.

  Known assemblies of this type comprise at least one worm, 1 driven in rotation, on the one hand parallel and near the bottom of the silo, around the vertical central axis of the silo, and on the other hand around itself, so as to entrain the material towards an opening provided in the center of the silo and at the base of which are disposed means for evacuating the

materials out of the silo.

  Furthermore, it is known from French Patent No. 9104315, in the name of the applicant, an extractor in which the screw is associated with a support frame having drive means capable of disintegrating the mass of material and causing the fall thereof , in the form of a blade whose

  2o horizontal edge is parallel and disposed above the screw.

  Silos are used to contain a variety of pulverulent materials that have inherent flow dynamics characteristics. A given extractor device may be suitable for one type of material and

  reveal unsuitable for other matters.

  Thus, the extractor described in the patent mentioned above, is suitable for materials flowing by gravity, such as for example sugar. The storage silos of this type of material may have a diameter up to

meters.

  For pulverulent or granular materials that do not flow or are difficult to flow by gravity, such as, for example, soybeans or livestock by-products, this type of extractor is not suitable. In addition, silos containing such materials are limited to a diameter of about 20

meters maximum.

  In addition, so-called intermediate materials (cement, clinker, minerals, plants) exhibit dynamic behavior in flow.

relatively unstable.

  Thus, according to the prior art, it is necessary to adapt the size of the silo and the extraction devices to the type of materials according to their mechanical flow characteristics, with the resulting economic consequences. The invention overcomes this situation and proposes an extraction assembly, 2 (capable of being placed in a silo of large diameter (60 m), and able to work with very different materials from the point of view of their behavior.

dynamic flow.

  To this end, according to the invention, the assembly for the extraction of pulverulent or granular materials stored in a silo, of the type comprising first extraction means, including a first worm, driven in rotation, of a parallel and near the bottom of the silo, around the vertical central axis of the silo, and secondly around itself, so as to cause the material to an opening in the center of the silo and the Placed with means for evacuation of materials out of the silo, is characterized in that it comprises second extraction means, arranged at a lower level with respect to the first extraction means, and suitable to resume, on a part of the silo bottom, the

material extracted by them.

  More specifically, the first extraction means are arranged so as to scan a portion of the bottom of the silo, to the edge of said opening which opens into a pit o are disposed said second extraction means, said pit being itself connected by a mouth to

means of evacuation.

  Advantageously, the pit is circular and centered on the vertical central axis

silo.

  Preferably, the second extraction means comprise a worm, is capable of scanning, in a circular motion of central vertical axis, the bottom of the pit, the screw being further driven by a rotational movement

  on itself, thanks to training means.

  According to a preferred embodiment, the assembly comprises a diametral beam resting on the walls and / or the opposite sides of the pit, cantilevered, and supporting said second screw and its drive means.

in rotation.

  Advantageously, the beam also supports the end

  proximal to the first screw (towards the central axis of the silo).

  More specifically, the first screw is integral, at its proximal end, with a protective casing, housing the means for driving the screw in rotation on itself, the casing resting on said beam by means

of turnover or equivalent.

  The distal end of the first screw, rests on the bottom of the silo via a pinion (or barrel wheel) cooperating with a rack and associated with drive means, to allow the movement of the screw by rotation in its bottom sweeping motion

silo.

  The first screw is associated with a support frame comprising drive means capable of disintegrating the mass of material and causing the fall thereof, and having a cover covering the first screw partially, at least on the side of the advancement of the screw in his sweeping motion

from the bottom of the silo.

  More particularly, the hood has on its face turned on the leading side of the material, gills may be closed

  partially, provisionally and adjustably.

  The invention also relates to a silo for the storage of pulverulent or granular materials, provided with extraction means and) evacuation of materials out of the silo, as mentioned above and

described below.

  More specifically, on the bottom of the silo (capable of being swept by the first screw) is provided an opening which opens into a pit, preferably circular and centered on the vertical central axis of the silo, and adapted to accommodate the second means extraction, said pit being itself

  connected by a mouth to the evacuation means.

  The invention will be well understood in the light of the description which follows,

  3o relating to an illustrative but non-limiting example of the invention, with reference to the accompanying drawings in which: - Figure 1 is a sectional view showing the extraction assembly of the invention, according to a vertical diametral plane of the silo ; - Figure 2 shows the extraction assembly of Figure 1, on an enlarged scale; - Figure 3 shows a sectional view along the axis 111-111 of Figure 2; - Figure 4 is similar to Figure 3, on an enlarged scale, the second screw being turned a quarter turn; FIG. 5 is a detailed view of the means for driving or rotating the second screw; FIG. 6 shows a detail view in section and in elevation of the drive and support means of the end of the first screw; FIG. 7 shows a detailed view of the closable openings provided on

  ) the support frame of the first screw.

  In Figure 1, there is shown an elevational sectional view, according to a

  vertical diametral plane of the silo, of the whole of the invention.

  The silo 1, which is only partly represented for reasons of scale and clarity, has a cylindrical shape with a diameter of about 60 meters, with a vertical central axis XX, and comprises a cylindrical wall 2, a circular bottom 3. The silo delimits a storage volume 4 intended to receive granular or powdery materials, FIG. 1 showing the silo) partially filled, the material forming a pile 5 (in a triangle seen in section) in

support on the wall 2 and the bottom 3.

  The silo 1 rests on the ground by a base 6, between which is the bottom 3 is delimited a space 7 accommodating means for evacuating the materials towards the outside 8 of the silo (arrows f) and comprising a chute 13 and a conveyor 14. According to the invention, the bottom 3 of the silo 1 is open on a circular portion 8 of its surface, centered on the vertical axis XX of the silo. The circular opening 8 opens onto a pit 9 centered on the X-X axis of the silo, comprising a

  cylindrical wall 10 and a circular base 11.

  The base 11 of the pit 9 is provided with a central outlet opening 12 opening into the interior space 7 between the base 11 and the bottom 3 of the silo, via a chute 13, itself located at the plumb with a recovery conveyor 14, opening to the outside 15 of the silo, through

of the wall 2.

  A diametrical beam 16 is provided in the pit 9 and rests on

  the wall 10, more precisely on two opposite shoulders 10A of this

  ) this. The beam 16 is hollow and comprises an upper panel 17 flush substantially at the bottom 3 of the silo, and a lower panel 18

  relatively close to the base of the pit 9.

  The materials are extracted from the silo, according to the invention, by first

  means 19 and second extraction means 20.

  The first extraction means 19 comprise a worm 21 (called first screw 21) driven in rotation parallel and close to the bottom of the silo, around the vertical central axis of the silo, so as to sweep the bottom 3

  3o of the silo according to a radius thereof.

  The first screw 21 is associated, at its proximal end (on the side of the axis XX), with a frame 22 centered on the axis XX, resting on the upper panel 17 of the beam 16, and integral with a radial frame 23 supporting the first screw 21. The distal end of the screw 21 is associated with a distal housing 24 resting on the bottom 3 while allowing the circular movement of the screw by

  driving means 25 arranged in the housing 24.

  1o The first screw 21 is also rotated around itself

  by means known in themselves (motor 26 and gear 27).

  The materials are thus extracted from the pile 5 and driven to the pit 9 by the

  double movement of the first screw 21.

  The second extraction means 20, arranged at a lower level relative to the first extraction means 19, comprise a worm 28 (called second screw 28) capable of scanning in a circular motion of central vertical axis, the bottom from the pit. The second screw 28 is furthermore animated with a rotational movement on itself. Ways

  driving the second screw 28 are described later.

  FIG. 2 is a view similar to that of FIG. 1, showing in more detail the means of the invention, the proportions not being respected for

reasons for clarity.

  With regard to the first extraction means 19, the frame 22 housing the motor 26 and the gears 27 (driving in rotation of the first screw 21 around itself), rests on the upper panel 17 of the beam 16 by bearings 29 or the like. Thus, the following associated elements: frame 22, support frame 23, first screw 21, distal housing 24 are capable of rotating about the axis X-X so that the screw 21 sweeps the bottom

silo.

  In the embodiment of Figure 2, the first screw 21 has a portion 30 without a screw, corresponding substantially to the portion of the screw

located above the pit 9.

  The driving means of the second screw 28 are arranged on the lower panel 18 of the beam 16, and comprise on the one hand a first motor 31 connected to a gearbox 32, for the rotation of the screw around its own axis, and secondly a second motor 33 for the

  rotation of the second screw around the X-X axis.

  FIG. 3 represents a sectional view along a diametrical vertical plane, of

  i5 the pit 9 and first and second extraction means.

  The pit 9 and these same means are shown in greater detail in FIG. 4, on a scale different from FIG. 3, and whose proportions have not been strictly respected, to make certain details more precise.

understandable.

  The beam 16 is provided on its lateral flanks 34 and 35, at its central portion, a central skirt 36 conical open downwardly. The lower diameter of the skirt 36 is such that it caps the discharge opening 12 (on the base 11 of the pit 9), and preferably protrudes from either side of the drive means of the second screw 28. , and covers the part

proximal to it.

  Figure 5 shows in detail the drive means of the second screw 28. The motor assembly 31 and gear housings 32A and 32B. The latter, integral with the screw 28, is disposed below the lower panel 18 of the beam 16, in a chamber 32C. The motor assembly 31 / housings 32A and 32B is mounted on a plate 37, disposed at the bottom panel 18 of the beam 16. The plate 37 is rotatably mounted with axis XX on bearings 38. The circular edge of the platinum is provided with a ring 39 adapted to mesh with a pinion 40 integral with the axis of the motor 33 at the output of the gear housing 33A. The motor 33 thus drives the plate and

  therefore the second screw 28 in rotation of axis X-X.

  FIG. 6 shows in section, along a diametrical vertical plane of the silo, the distal housing 24 including the means 25 by which the first screw 21 rests on the bottom of the silo and is driven in a scanning movement

from the bottom of the silo.

  A pinion 41 is rotatably mounted on a shaft 42 fixed on the proximal wall 43 of the casing 24 and on a vertical inner sidewall 44. The pinion 41 cooperates

  with a rack 60 provided the bottom 3 of the silo.

  The pinion is rotated by a motor 45 fixed on the proximal face of the proximal wall 43 of the housing, and whose shaft is integral with a pinion 46 associated with a chain 47 cooperating with a pinion 48 mounted on

the tree 42.

  Referring again to Figures 3 and 4, there is provided means for driving the materials, associated with the first screw 21. These means comprise a cover 49, in the form of a radial direction canopy, along the frame 23, comprising two panels 50 and 51 forming a V open towards the bottom of the silo and covering the first screw 21. A third vertical panel 52 extends one of the panels of the V, downwards, behind the V. The frame 23 rests on the bottom of the silo via wheels or rollers before 53 and rear 54 (Figure 4); Furthermore, FIG. 7 shows schematically and partially the panel 50 of the cover 49, turned on the leading side of the material, comprising louvers 55 that can be closed partially, temporarily and adjustably, by sliding shutters 56. It is thus possible to improve, by opening more or less gills, the operation of the first screw at the start and during scanning on the bottom of the silo. At startup, the gills are closed, and the first screw is driven only in rotation around itself, on site. Then, once the material is released, the screw starts its sweeping movement, and then open the gills 55 (by sliding the movable flaps 56). This makes it possible to increase the extraction rate. The assembly of the invention also comprises means for ventilating and cooling the rotating drive means of the first and

second screw.

  Said means include a member 57 adapted to generate a current or air flow and opening into the hollow beam 16. The air being in contact with the drive means (31 and 33) of the second screw 28, takes calories to these. The current of air continues its way towards the interior of the frame

  22 center, housing the drive means 26 and 27 (rotation on it).

  same) of the first screw, take some calories from them. The air is then introduced into a duct 58 forming a radial spar of the frame 49 supporting the first screw. The conduit 58 opens into the housing 24 in which are arranged the drive means 45 of the first screw

in his sweeping motion.

3)

  The operation of the extraction assembly of the invention is as follows.

  Materials capable of flowing by gravity fall into the pit and are first evacuated by the second screw 28 which extracts and discharges the materials until they form an annular heap with a triangular section, such as as shown in Figures 1 and 2. The first screw 21 is then actuated, first in rotation on itself, then sweeping the bottom 3 of the silo. The materials are driven by the first screw 21 to the pit 9 or they fall, and are then taken up by the second screw 28 sweeping the

base of the pit.

  I (In the case of materials not flowing by gravity, the first 21 and second 28 screws are rotated on itself first.

  then sweeping respectively the bottom of the silo and the base of the pit.

  The invention is not limited to the mode described. For example, the second screw 28 may be replaced by other means such as a scraper chain or the like. The invention also relates to a silo for the storage of pulverulent or granular materials, provided with the first and second means

  extraction as mentioned and described above.

Claims (10)

  1. Set for the extraction of pulverulent or granular materials stored in a silo, of the type comprising first extraction means, including a first worm, driven in rotation, on the one hand parallel and near the bottom of the silo , around the vertical central axis of the silo, and secondly around itself, so as to cause the materials to an opening provided in the center of the silo and at the base of which are arranged means of evacuation of materials out of the silo, characterized in that it comprises second extraction means, arranged at a lower level with respect to the first extraction means, and able to resume, on a part of the   bottom of the silo, the material extracted by these.   2. The assembly of claim 1, characterized in that the first extraction means are arranged to scan a portion of the bottom of the silo to the edge of said opening which opens into a pit o are disposed said second means of extraction, said pit   being itself connected by a mouth to the means of evacuation.   3. Assembly according to one of claims 1 or 2, characterized in that   the second extraction means comprise an endless screw, capable of scanning, in a circular motion of central vertical axis, the bottom of the pit, the screw being furthermore animated with a rotational movement on   itself, thanks to training means.   4. Assembly according to one of claims 1 to 3, characterized in that   has a diametrical beam resting on the walls and / or the opposite sides of the pit, cantilevered, and supporting said second screw   and its rotation drive means.   5. An assembly according to claim 4, characterized in that the beam also supports the proximal end of the first screw (towards the axis central silo).   6. Assembly according to one of claims 1 to 5, characterized in that   the first screw is integral, at its proximal end, with a protective casing, housing the means for driving the screw in rotation on itself, the housing resting on said beam by means of rolling or equivalent. I0   7. Assembly according to one of claims 1 to 8, characterized in that   the distal end of the first screw, rests on the bottom of the silo via a pinion (or barrel wheel) cooperating with a rack and associated with drive means, to allow the movement of the screw by rotation in its sweeping motion the silo bottom.   8. Assembly according to one of claims 1 to 7, characterized in that the   first screw is associated with a support frame comprising attack means adapted to disintegrate the mass of material and cause the fall thereof, and having a cover covering the first screw partially, at least on the side of the advancement of the screw in his movement of sweeping the bottom of the silo.   9. An assembly according to claim 8, characterized in that the cover has on its side facing the leading side of the material, gills may be closed partially, temporarily and adjustable. 10. Silo for the storage of powdery or granular materials, provided   of the extraction assembly according to one of claims 1 to 9, the bottom   silo (capable of being swept by the first screw) comprising an opening which opens into a pit adapted to accommodate the second extraction means, said pit being itself connected by a mouth evacuation means.