EP0051032A1 - Storage bin for granular materials - Google Patents

Abstract

The invention relates to bins for storing granular materials. According to the invention the bin comprises two concentric vertical skirts (11, 12) forming two cells (13, 14) resting on a solid base (10); the base being characterised in that it forms, jointly, a floor (10A), means (15, 20) suitable for permitting complete emptying of the bin, with the aid of discharge passages (17, 25) provided in the floor, a series of galleries with radiating axes disposed vertically above the abovementioned discharge passages. Application to the storage of pulverulent materials. <IMAGE>

Description

The present invention relates, in general to silos intended for the storage of powdery materials, comprising at least one skirt extending vertically and resting on a horizontal flat floor, said skirt forming a storage cell.

Such silos comprise, in known manner, means capable of allowing the evacuation of the stored product, these means being generally arranged in the lower part of the silo.

The means provided for ensuring the evacuation of the stored product can be classified into two categories, namely, the means capable of ensuring evacuation called for convenience "forced", and the means capable of ensuring evacuation by "gravity".

In the first category of silos set out above, the document AUFBEREITUNGS-TECHNIK, vol. 17, no. 11, 1976 DEVerlag für Aufbereitung Schirmer & Zeh WIESBADEN (DE) W. KLUGER: " _B eladeanlagen fur mehlförmige Schüttgüter" page 562 column 1 lines 15-54 figure 9, teaches a silo whose floor has a central evacuation hole, as well that a series of asymmetrical bosses surrounding the aforementioned central evacuation hole each of which is disposed a blowing means supplying openings provided in said bosses.

In a silo as above, the presence of numerous blowing points implies a complex and costly blowing installation. In addition, the evacuation of the product by a single central point is not likely to allow rapid emptying of the silo.

French patent application No. 2,395,929 of June 28, 1977 has also been proposed a device allowing the complete pneumatic emptying of a flat-bottomed storage enclosure containing granular products.

In this embodiment, the floor comprises a series of channels in communication with a peripheral channel connected to a pneumatic source, the bottom also comprising a series of radial reinforcing cores.

In such an embodiment, the evacuation is also carried out by a central evacuation and we find the same disadvantages than those cited with regard to the aforementioned document; moreover it is understood that the realization of a multiplicity of channels with blowing orifices leads to an embodiment which is not free from difficulties of all kinds from which it results in a high cost price.

In the second category silos, in which the product is discharged only by gravity, provision has already been made in the floor for a series of passages, all of reduced diameters, arranged regularly, these passages each being equipped with a valve, and the silo resting on a base made up of a multiplicity of posts.

Generally, in the above silos, the pulverulent material discharged through the passages and the valves is taken up by conveyor means such as conveyor belts provided under the floor and from which it can be transported outside the limits of the silo by all appropriate means.

A drawback observed in silos of the above kind concerns the emptying of the pulverulent material; indeed, the emptying being carried out by gravity, and the floor being flat, there remains in the bottom of the silo a certain quantity of pulverulent material more or less important, depending on whether the material tends to clot, which implies personnel interventions inside the storage cell, to completely empty the silo.

Another drawback noted concerns the posts on which the floor rests; these posts, given their large number, constitute a hindrance for the placement of the conveying means, taking up the pulverulent material delivered by the valves.

In addition, the cost of producing such silos is high, in particular because the construction of a multiplicity of support posts requires time, independently of complex production problems.

The present invention relates more particularly to the silos of the second category, that is to say those in which the bottom of the cell is arranged to ensure the evacuation of the product by gravity; its object is a silo whose configuration of the lower part makes it possible to eliminate the drawbacks hitherto observed in this type of silo and this, with an easy implementation from where it results in lowered construction costs.

For this purpose, a silo according to the invention, of the type comprising at least one storage cell constituted by a vertical skirt whose bottom consists of a horizontal floor resting on support means, the floor comprising a multiplicity of clean passages to the evacuation of the stored pulverulent material, in association with valves capable of delivering the pulverulent material to conveyor means, is characterized in that it comprises a monobloc base adapted to jointly form a floor, support means, and galleries with radiating axes each capable of receiving a conveyor in order to transfer the pulverulent material outside the limits of the silo, and in that the upper face of the floor comprises on the one hand, in its center a cone of revolution s' extending upward being axial to the skirt, and on the other hand, a series of dihedrons having their radiating intersection lines and inclined up and down starting from the skirt towards its axis.

According to another characteristic of the invention, the faces of two consecutive dihedrons form between them, a corridor whose flat bottom, constituted by the floor comprises evacuation passages, while the cone of revolution is surrounded at its base with a crown with evacuation passages, the said passages made both in the bottoms of the corridors and in the crown being located directly above radiating galleries provided under the floor.

It will be observed that the configuration of the lower part of a silo according to the invention solves in a simple and economical manner the problems hitherto posed, both with regard to the construction which is considerably simplified (absence of posts) and as regards operation, the fact that the complete and rapid emptying of the silo can be carried out without manual intervention.

Indeed, the arrangement _of dihedrons, forming between them radial corridors with bottoms comprising a plurality of passages, and of the cone of revolution with its crown also comprising passages, all these passages being located directly above transport means arranged in corresponding galleries, means that the stored product can be evacuated from the silo without any external intervention.

In addition, the production of a silo according to the invention being extremely simplified compared to the prior art, an operation which gives complete satisfaction is combined at a lower cost.

On the other hand, a silo according to the invention can be produced with a single skirt forming a storage cell, or with two concentric skirts forming two storage cells, each of said cells having its own means for discharging the product; in such an embodiment, the so-called interior cell comprises for this purpose a conical surface of revolution whose base is surrounded by a crown with evacuation orifices, while the annular cell called the exterior, comprises a plurality of dihedrons with lines of radiating intersection, with, between these, evacuation corridors whose base has a constant width, each of the bases comprising a plurality of evacuation orifices, the evacuation orifices of said cells opening into the galleries.

• la figure 1 montre en élévation et coupe axiale un silo conformément à l'invention selon la ligne I-I indiquée à la figure 2 ;
• la figure 2 est une vue en coupe avec arrachement partiel suivant la ligne brisée indiquée par II-II à la figure 1;
• la figure 3 est une vue en coupe suivant la ligne III-III de la figure 2 ;
• la figure 4 est une vue en coupe suivant la ligne IV-IV de la figure 3 montrant en particulier en plan la disposition des galeries formées dans le socle ;
• la figure 5 est une vue partielle en coupe suivant la ligne V-V de la figure 4.

Other characteristics and advantages of the invention will emerge moreover from the description which follows, given by way of example, with reference to the appended drawings in which:

• Figure 1 shows in elevation and axial section a silo according to the invention along line II indicated in Figure 2;
• Figure 2 is a sectional view partially broken away along the broken line indicated by II-II in Figure 1;
• Figure 3 is a sectional view along line III-III of Figure 2;
• Figure 4 is a sectional view along line IV-IV of Figure 3 showing in particular in plan the arrangement of the galleries formed in the base;
• FIG. 5 is a partial view in section along the line VV in FIG. 4.

In the embodiment chosen and shown in the figures, the silo according to the invention comprises a solid circular base indicated generally at 10 surmounted by two concentric skirts 11, 12, forming two storage cells respectively interior 13, and exterior 14, this the latter being annular. The base 10 forms a floor 10A common to the cells, the floor of the interior cell 13 being arranged with, in its center, a conical surface of revolution 15 extending upwards; between the base of this conical surface of revolution and the lower end of the skirt 12 is formed a circular crown 16 in which are formed evacuation passages 17 (Figures 2 and 3) distributed along a circumference and suitably arranged as well as it will be specified in the following.

As for the outer cell 14, it comprises in its lower part a series of dihedrons indicated generally by 20, having two inclined faces 20A-20B, (FIG. 5 in particular), forming a radial intersection edge 20C inclined with respect to a horizontal plane, the inclination of this edge being, starting from the skirt 11 from the top to the bottom. In the example shown, the facing faces of two consecutive dihedrons provide an evacuation corridor 21 (FIG. 5 in particular ) whose bottom 21A - formed in fact by the upper surface of the flat floor 10A. - has a constant width, with a radiating axis and, on either side of this axis, a series of evacuation passages 25.

It will be noted that the evacuation passages 17 provided in the crown 16 are located in the extension of the evacuation passages 25 formed in the bottom 21A of the aforementioned corridors 21.

The evacuation passages 17 and 25, formed in the floor 10A, have a frustoconical surface whose large base forms an orifice in the upper surface of the floor and the small base an orifice in the lower surface of the floor.

Each of the cells 13, 14 therefore has its own means for discharging the product (conical surface and dihedrons) capable of directing the material towards the evacuation passages, thus allowing complete emptying of the silo. Under the floor 10A, the base 10 comprises support means constituted by vertical walls 30, forming between them a plurality of galleries 32 (FIG. 4), arranged directly above the evacuation passages 17 and 25, each gallery thus formed opening on the one hand, on the outside and, on the other hand, in a central chamber 33.

Within these galleries can be placed conveyor means, such as conveyor belts indicated in broken lines by 35, these being placed in such a way that they lie directly above the evacuation passages 17, provided for this purpose in the crown 16, and evacuation passages 25 provided in the flat bottom of the corridors 21.

It will be noted that below the dihedrons 20, that is to say at a location devoid of galleries, the base can be reinforced by filling with concrete as indicated at 40 in FIG. 1.

Of course the base 10 comprises a sole 41 forming foundations for the construction, this sole advantageously forming an integral part of the base.

In the upper part, the silo usually comprises a compartment 43 formed by two horizontal walls 44, 45, the latter comprising openings 46 suitable for admitting the pulverulent material to be stored in the interior and exterior cells 13, 14.

Such a base structure, made of concrete offers the advantage of a simple and rapid production, at the same time as it allows an easy emptying of the two cells and a practical transfer of the material outside the limits of the silo.

Of course, the invention is not limited to the embodiment chosen and shown but could be subject to modifications without departing from the scope of the present invention.

Claims (8)

1. Silo for the storage of powdery materials of the kind comprising, at least one storage cell constituted by a vertical skirt whose bottom consists of a horizontal floor resting on support means, the floor comprising a multiplicity of passages suitable for the evacuation of the stored pulverulent material, in association with valves capable of delivering the pulverulent material to conveyor means, characterized in that it comprises a _. monobloc base (10) adapted to jointly form a floor (LOA), support means (30), and galleries (32) with radiating axes each capable of receiving a conveyor (35) in order to transfer the pulverulent material into outside the limits of the silo, and in that the upper face of the floor (10A) comprises on the one hand, in its center a cone of revolution (15) extending upwards being axial to the skirt (11), and, on the other hand, a series of dihedrons (20) having their lines of intersection (20C) radiating and inclined up and down starting from the skirt towards its axis. 2. Silo according to claim 1, characterized in that the facing faces of two neighboring dihedra (20) form, with the upper surface of the floor (10A) an evacuation corridor (21) with a flat bottom. 3. Silo according to claim 2, characterized in that the evacuation corridors (21) at floor level (lOA) have parallel straight lines on either side of an axis of radiating symmetry. 4. Silo according to any one of the preceding claims, characterized in that the base of the cone of revolution is surrounded by a floor surface forming a crown (16) with a plurality of evacuation passages (17). 5. Silo according to any one of the preceding claims, characterized in that it comprises two concentric skirts (11-12) respectively inner and outer thus providing two cells (13,14), the cell (14) formed between the skirt inner and the outer skirt being annular. 6. Silo according to claim 5, characterized in that the floor portion forming the annular cell bottom (14) comprises a series of dihedrons (20) forming between them, evacuation corridors (21) with a horizontal base of constant width comprising evacuation passages, while the surface of the floor affecting the interior cell (13) comprises a cone of revolution (15), the base of which is surrounded by a crown (16) comprising a series of discharge passages (17). 7. Silo according to any one of the preceding claims, characterized in that the evacuation passages (17, 25) formed in the floor (10A) have a frustoconical surface, the large base opening onto the upper surface of the floor and the small base in the galleries (32). 8. Silo according to any one of the preceding claims, characterized in that the bases of the evacuation corridors (21) comprise two series of evacuation passages (25) arranged on either side of an axis of symmetry radiant.

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