EP0443970B1 - Tight silo with suspended envelope and method of manufacturing it - Google Patents

Abstract

Silo for various products in bulk, in particular plastic bottles, characterised by an envelope (2) constituting its walls which is formed from sheets of sheet metal (3) suspended or attached to horizontal (4) and vertical (5) support sections constituting an exterior framework (6). This invention is of particular interest to manufacturers of equipment for the bulk storage of products. <IMAGE>

Description

The present invention relates to a sealed silo with a suspended envelope, in particular with a suspended metallic envelope, and to a method of constructing this silo.

One of the applications of the invention relates to plastic bottle silos, produced in large series in companies for bottling mineral water or other drinks.

In this area relating to human nutrition, the greatest possible precautions regarding cleanliness and hygiene are required.

On these production sites, plastic bottles are produced, upstream of the bottling line, for example of the polyvinyl chloride type, called PVC, by a first chain of extruders intended to produce at high speed by extrusion- blowing plastic containers, in particular PVC, intended to contain the mineral water thus distributed to consumers.

Due to the high production rate of these bottles and the high, but often discontinuous filling rate, it is necessary to provide a buffer stock in several silos.

With regard to food, the greatest precautions in terms of sanitary cleanliness and the maintenance of minimum bacteriological conditions are essential.

Furthermore, for these containers of low commercial value and reduced residence time, only large capacity silos are economically attractive.

In addition, these products are stored shortly after their manufacture and, both the material used and these forms in bottles which are slightly open volumes, require ventilation or natural or artificial aeration for the evacuation of diffused products, mainly chlorinated.

This phase is conventionally called dechlorination.

If these chlorine products are not properly disposed of, they remain in the bottles and are transmitted to the contents after filling. This unpleasant taste cannot be appreciated by consumers.

For these purposes, there are already ventilated silos, formed of a metal base inclined towards a discharge outlet and of a side and upper surface screened on a framework.

If ventilation is perfectly sufficient for complete dechlorination, at least in the upper part, the conditions of resistance over time and perfect sanitary cleanliness are not correctly fulfilled due to the difficulties of access.

Furthermore, the shape of the bottles of square or rectangular section, arranged in bulk in the silo, and their low weight do not facilitate their evacuation movement on the inclined outlet plane.

The staff is obliged to push or help certain bottles to descend along the inclined plane and the discharge chute by repeated blows on the rear face of the sheet metal plates. The same is true for bottles stuck at the corners.

These sometimes violent blows deteriorate the base of the silo, at the level of the separation of the plates, and deform the latter by bumps and impacts in such a way that they no longer constitute a sufficiently flat sliding surface.

In order to facilitate the intervention of cleaning and disinfection teams, the base of this type of silo can be dismantled in the form of removable panels which must be dismantled and moved to ensure sufficient cleaning and reassembly.

In order to avoid these interventions, an automatic internal cleaning system can be provided, for example with turnstiles or rotating balls, or any other fluid pressure cleaning assembly, performing the same roles and work.

This supposes silos that are completely and perfectly sealed, with a smooth interior surface, that is to say surfaces free of protruding edges, roughness or any other irregularities or defects in the material.

Furthermore, in order to guarantee the necessary mechanical rigidity, the large dimensions necessary for the silos lead to the use of thick sheets, which are therefore heavy, expensive and difficult to implement.

Also known are double-walled silos of the type described in US Patent No. 1,465,745, and corresponding to the preamble of claim 1, with a fixed outer wall sealing and an inner wall with removable panels for allow cleaning. Unfortunately, if the tightness of the outer wall allows the installation of ventilation, the resistance of the inner wall is insufficient and the roughness that it presents are disadvantages for the desired application.

The object of the present invention is to remedy these various drawbacks by proposing a silo with a new structure which is perfectly sealed, light, smooth and resistant, which can house a set of blowing and integrated cleaning.

To this end, the invention relates to a silo for various bulk products which is characterized in that on the perimeter lines of the external framework are hung by upper transverse edges for hanging the sheets of a rigid material in small formats, each sheet hung on one of the profiles of a perimeter line being joined to the lower edge of the adjacent upper sheet by a weld in the right or in the vicinity of the profile covered by the transverse edge of said sheet, the other sides of each sheet being joined to the other sides of the adjacent sheets by covering and welding.

The invention also relates to the correlative method of constructing a silo or a closed and sealed enclosure with a suspended envelope.

• légèreté de structure par la possibilité d'employer des tôles minces ;
• diminution notable du coût de la matière utilisée ;
• facilité de fabrication ;
• suppression des panneaux démontables ;
• intérieur lisse par la soudure en continu de toutes les tôles ;
• possibilité d'installer un système de lavage intérieur parfaitement intégré ;
• possibilité d'incorporer un ensemble de soufflage aux angles pour désinfecter et pour enlever les bouteilles restées bloquées aux angles ;
• étanchéité intégrale du silo ;
• surface intérieure parfaitement lisse par l'absence de toute aspérité, angles vifs ou bords tranchants pouvant retenir des particules, salissures diverses ou détériorer ou affaiblir les bouteilles par friction ;
• le concept de constitution d'un silo par une enveloppe suspendue à une armature métallique extérieure permet d'utiliser les tôles les plus fines sans aucun élément supplémentaire de solidarisation et d'étanchéité autre que les cordons de soudure le long des bords de la tôle supérieure recouvrante ;
• chaque tôle est suspendue individuellement sur un élément d'ossature garantissant l'absence de tension mécanique sur les soudures provenant du poids de l'enveloppe ;
• les soudures sont effectuées au droit des pliures de l'aile d'accrochage sur l'ossature garantissant ainsi une meilleure résistance mécanique de l'enveloppe.

Multiple and notable advantages result from this mode of constitution and manufacture of a silo and of the silo according to the present invention:

• lightness of structure by the possibility of using thin sheets;
• significant reduction in the cost of the material used;
• ease of manufacture;
• removal of removable panels;
• smooth interior by continuous welding of all sheets;
• possibility of installing a perfectly integrated interior washing system;
• possibility of incorporating a blowing assembly at the corners to disinfect and to remove bottles that are blocked at the corners;
• complete sealing of the silo;
• perfectly smooth interior surface due to the absence of any roughness, sharp angles or sharp edges which can retain particles, various soiling or deteriorate or weaken the bottles by friction;
• the concept of constituting a silo by an envelope suspended from an external metal frame allows the use of the thinnest sheets without any additional element of joining and sealing other than the weld beads along the edges of the upper sheet overlapping;
• each sheet is individually suspended on a framework element guaranteeing the absence of mechanical tension on the welds originating from the weight of the envelope;
• the welds are carried out in line with the folds of the attachment wing on the frame, thus guaranteeing better mechanical resistance of the envelope.

• . La figure 1 est une vue générale d'ensemble en perspective simplifiée avec écorché du silo selon l'invention avec écorché longitudinal ;
• . la figure 2 est une vue schématique en perspective illustrant le recouvrement périphérique supérieur ;
• . la figure 3 est une vue en perspective schématique illustrant la constitution de la partie supérieure ;
• . la figure 4 est une vue en perspective schématique simplifiée illustrant la constitution générale intérieure du silo ;
• . les figures 5 et 6 sont des vues schématiques simplifiées en perspective illustrant respectivement vue de l'avant avec écorché et vue de l'arrière une croisée des profilés d'ossature longitudinaux et verticaux ;
• . la figure 7 est une vue schématique partielle en coupe verticale sur la partie cylindrique et supérieure ;
• . la figure 8 est une vue schématique en coupe verticale sur le pourtour de raccordement entre la partie cylindrique et la partie conique ;
• . la figure 9 est une vue schématique en coupe verticale sur la partie conique ;
• . la figure 10 est une vue schématique mixte montrant la configuration générale de l'ensemble d'évacuation des eaux de lavage de l'intérieur du silo ;
• . les figures de 11 à 15 sont des coupes transversales destinées à illustrer divers types d'ancrage des parois suspendues aux profilés d'ossature.

The technical characteristics and other advantages of the invention are set out in the description which follows, given by way of nonlimiting example on an embodiment with reference to the accompanying drawings in which:

• . Figure 1 is a general overview in simplified perspective with cutaway of the silo according to the invention with longitudinal cutaway;
• . Figure 2 is a schematic perspective view illustrating the upper peripheral cover;
• . Figure 3 is a schematic perspective view illustrating the constitution of the upper part;
• . Figure 4 is a simplified schematic perspective view illustrating the general internal constitution of the silo;
• . Figures 5 and 6 are simplified schematic views in perspective respectively illustrating front view with cutaway and rear view a cross of the longitudinal and vertical frame profiles;
• . Figure 7 is a partial schematic view in vertical section on the cylindrical and upper part;
• . Figure 8 is a schematic view in vertical section on the periphery of connection between the cylindrical part and the conical part;
• . Figure 9 is a schematic view in vertical section on the conical part;
• . FIG. 10 is a mixed schematic view showing the general configuration of the assembly for discharging the washing water from the interior of the silo;
• . Figures 11 to 15 are cross sections intended to illustrate various types of anchoring of the walls suspended from the frame profiles.

The general inventive idea consists in producing a closed storage volume, in particular a sealed sealed silo, in particular for bulk bottles, from an external framework on which sheets of sheet metal, in particular of thin sheet metal, are hung, each of they ensuring with its neighbor a sealing overlap by weld beads on the periphery along its edges including at least one horizontal connection weld along and in line with or in the vicinity of each bend of attachment of each sheet metal sheet constituting with the lateral extension of a hanging wing.

More specifically, in order to make it possible to show the possible implementation of the general inventive idea indicated above, the invention will be described in detail below with reference to the various accompanying figures.

A silo 1 is constituted by an envelope 2 formed of a plurality of sheets such as 3, for example of thin sheet metal, individually suspended from horizontal 4 and vertical 5 bearing profiles of a external framework 6, preferably metallic, taking the general external shape of the body 7 of the silo 1. In the case of silo 1 as shown in FIG. 1, the body 7 consists of an upper volume 8 of generally semi-parallelepiped shape extended downwards by a pyramidal hopper 9. The framework will then have a general parallelepipedo-pyramidal shape constituted by the perimeter and stepped lateral succession of horizontal 4 and vertical 5 support profiles arranged in several superposed stages 10, 11, 12, 13 and 14.

In accordance with the variant shown, each horizontal perimeter of the hopper 9, or of the upper volume 8 such as respectively 15 and 16 is formed of a succession of sections such as 17 or 18. Similarly, each oblique amount of the hopper 9 or vertical of upper volume 8 such as 19 and 20 respectively is formed by a succession of inclined 21 or vertical 22 sections.

On the horizontal support sections 4 are hung the sheets 3 of thin sheet metal, for example metal, by means of upper longitudinal attachment wings 23 which they have in the upper part, shaped in their upper edge 24. These wings are formed by folding the upper edge 24 to form a transverse support plate 25 with a return 26 for lateral immobilization allowing it to perfectly fit the adjacent bearing profile between two of its consecutive edges and to hang thereon to press on two consecutive faces in order to wedge-hook each sheet sheet in accordance with the invention.

The sheet metal sheets 3 are hung directly on the adjacent support profile or on an auxiliary attachment profile 27 attached to it in order to carry out the attachment.

According to a variant shown, the leaves each also have at least one lateral attachment wing such as 28 shaped for example in the same way in a lateral edge 29, each being wedged on a corresponding vertical auxiliary attachment profile such as 30.

This double attachment ensures effective wedging of the sheets 3 for vertical and lateral forces.

The sheets are of such dimensions that they overlap each other on peripheral overlapping strips such that 31 of minimum width 32 sufficient to achieve sealing and overall cohesion by horizontal weld beads such than 33 and verticals such as 34 (Figure 5). These peripheral bands break down into horizontal 35 and vertical 36 bands.

It is important to note that the horizontal and vertical overlaps are carried out opposite the horizontal and vertical load-bearing sections of the framework just in line with the fold of each edge comprising a fastening wing so as to facilitate the execution of the welding and its mechanical strength. The overlaps are also made in the shape change and connection bending zone located at the base of the vertical volume at the connection with the hopper 9. In this connection zone, the upper support sections of the hopper 9 and lower of the upper volume 8 are adjacent and the sheets of the first stage of the upper volume have a curved and rounded lower covering edge 37 to ensure continuity in tangent with the inclined hopper plane (Figure 8).

As indicated, the lower part or hopper 9 is of convergent downward shape, conical, pyramidal or other, produced in the same way by hooking and joining together or overlapping identical sheets 3 on the frame profiles, at the using their upper longitudinal wing 23 for attachment. As previously, according to a variant, the sheets forming the envelope of the hopper are also wedged or immobilized laterally by additional lateral wings 38.

This lower part of general pyramidal shape is produced according to the same general principle of construction and constitution allowing the use of sheets of thin sheet metal.

Both for the upper volume 8 and for the hopper 9, corner sheets 39 and 40 respectively are necessary. They have two perpendicular planes 41 and 42, 43 and 44.

For reasons of rigidity and uniformity, each plane has its longitudinal, upper and lateral attachment wing.

Referring to FIG. 2, the silo 1 is closed in the upper part by a cover plane 45 constituted in the same way by sheet sheets 46, hung horizontally on support profiles 47.

A distinction is made between edge bearing profiles 48 and 49 on which the sheets adjacent to the border perimeter 50 are hung. These sheets have raised attachment wings 51 constituting the extension of the plane of the sheet by a rounded fold 52.

The upper end of the sheets of the last side wall stage of the upper volume 8 also has a curved and rounded upper covering edge 53 to ensure tangent continuity with the sheets of the covering plane 45. These edges are welded to ensure the sealing required.

The cover-carrying profiles 47 criss-cross the upper space and receive the covering sheets 46 which hook onto the cover plane 45.

Crossbars of stiffening are provided such as 54 each comprising a lift pad 55 to which each cover sheet 46 is secured in an additional manner. Because of their horizontal position and their small thickness, these sheets require additional support provided by each lift pad 55.

For the purposes of the converging lower shape, in the lower part of the silo, some of the sheet metal sheets have a general trapezoidal or triangular shape.

In this region, an injection assembly 56 has been provided for blowing a neutral gas or sterile air to ensure ventilation cooling, degassing, aeration and the spraying of water and cleaning and disinfection products, but also to release by jets of compressed air certain bottles which would be stuck or in opposite presentation.

This assembly is formed, for example, of a plurality of converging oblique ramps such as 57. These preferably consist of oblique tubes 58 pierced with orifices 59 arranged along the oblique edges at the junction of the inclined planes forming the hopper. Additional reinforcing sections 60 and 61 improve, if necessary, the mechanical rigidity (Figures 4 and 9).

An upper hatch allows the filling of the silo and a lower hatch the exit of the stored products (not shown).

A support 62 with four feet such as 63 carries the entire silo.

The silo comprises in the lower part a device 64 for collecting and evacuating cleaning water, shown diagrammatically in FIG. 10. This is supported by a suspension arm 65 and consists of a lower cone 66 whose outlet communicates with an exhaust pipe 67.

The side wall of the cone is connected to the base of the hopper by a junction formed by a baffle 68 fitted with a seal 69, constituted by a lower wing 70 in engagement with the sheet of sheet metal at the lower end.

Various types of section of load-bearing profiles are possible. By way of example, five variants have been shown in Figures 11 to 15.

A distinction is made between simple sections with rectangular section 71 (FIG. 11), with circular section 72 (FIG. 12), with enlarged section 73 upwards for the formation of a hooking shoulder by an additional wing 74 (FIG. 13) or an additional added profile 75 (FIG. 14).

There are also double profiles such as 76, 77 for which the wing of the sheet 3 has a return 78 upwards and is sandwiched between the two superimposed profiles.

It goes without saying that many other forms of load-bearing profiles are suitable.

Likewise, the nature and constitution of the sheets, as much by their material as by their thickness and their general shape, matter little, insofar as their inter-joining and their attachment remain possible.

The invention also relates to the method of constructing a sealed silo.

This process consists in constructing on the whole surface of the silo body an external framework in profiles having several horizontal perimeter lines at different levels formed by a succession of profiles. These perimeter lines are connected at intervals by vertical sections. The method then consists in conforming with each upper edge of each sheet of thin sheet metal limited in size, an upper attachment wing on each profile of the frame and on at least one lateral wing. These wings are formed, for example, by a double angle bend with return allowing a hanging with wedging effect.

The process finally consists in sealing the silo by welding the lower edges of the sheets of thin sheet metal to the right or in the vicinity of the first fold forming the attachment wing disposed immediately below and ensuring complete sealing by welding the lateral edges superimposed, leaving a minimum overlap strip.

The upper cover of the silo is made in the same way as the lower hopper of pyramidal shape.

The connection zones between the vertical lateral surface and the hopper as well as with the cover plane are made by means of curved overlapping edges.

Claims (5)

1. Leaktight silo having an external framework (6) of tubular profiled sections (4, 5) and having a lateral surface formed of a plurality of small sheets of a rigid material having a plurality of successive peripheral rows of profiled framework sections connected to one another by connection struts, characterised in that the sheets (3) are hooked on these peripheral rows via transverse upper fastening edges, each sheet hooked on one of the profiled sections (4, 27) of a peripheral row being connected to the lower edge (32) of the adjacent upper sheet by a weld at right angles to or in the vicinity of the profiled section (4) overlapped by the transverse edge of the said sheet, the other sides of each sheet being connected to the other sides of the adjacent sheets by overlapping and welding.
2. Silo according to Claim 1, characterised in that the attachment edges are wings (23) formed as a result of the upper transverse edge (24) of each sheet being folded.
3. Silo according to Claim 2, characterised in that each wing is formed by a double right-angled fold (25, 26) delimiting a space which is the width of the profiled section to which it is to be attached.
4. Silo according to any one of the preceding claims, characterised in that the sheets are of thin sheet metal.
5. Method of constructing a silo, characterised in that it consists in constructing an external framework of welded or assembled profiled sections having a plurality of horizontal peripheral rows at various levels formed by a series of profiled sections, these rows being supported at intervals by connection struts; and in that each upper edge (24) of each surface of thin sheet metal of restricted size is then shaped with an upper transverse hooking-wedging edge (23) on each profiled section of the framework or on an attached supporting profiled section, the said hooked edges being in the form of a wing formed by a double right-angled fold with a return (25, 26) for example, which wing is intended to delimit a space corresponding to the supporting surface of a profiled section of the framework or of an attached profiled section intended for the same use, enabling the part to hook with a wedging effect; and in that the silo is rendered leaktight as a result of the lower ends of the sheets of thin sheet metal being welded at right angles to or in the vicinity of the first fold of the piece of sheet metal located immediately below; and in that complete leaktightness is ensured as a result of the lateral edges which are superimposed at the lateral edges of the adjacent sheets being welded.

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