WO1983002130A1

WO1983002130A1 - Wall element for a container such as a silo

Info

Publication number: WO1983002130A1
Application number: PCT/SE1982/000415
Authority: WO
Inventors: Sven-Erik Ahl; Lars-Bertil Nilsson
Original assignee: Sven-Erik Ahl; Lars-Bertil Nilsson
Priority date: 1981-12-08
Filing date: 1982-12-07
Publication date: 1983-06-23

Abstract

When a silo (26) is filled with slow-running material, this has a tendency to stick on the walls of the silo. This is avoided in accordance with the invention, by constructing wall elements (1) consisting of stackable units (2A and 2B) having a cross-section in the shape of a trapezium with the smaller (4 and 6) of the two parallel sides (4, 6 and 7) facing upwards.

Description

Wall element for a container such as a silo

The present invention relates to a wall element for containers such as silos. Such containers consist of a surrounding wall and a bottom with an opening for removing the contents. Known containers have the drawback that, when filled with slow-running material, the material has a tendency to stick to the walls, which is not desirable. Another drawback with known containers is that it is difficult to make_, the surrounding walls suffi¬ ciently stable to withstand the pressure arising when the container is full.

The object of the present invention is to eliminate the drawbacks mentioned above, and this is achieved by using units which are stacked one on top of the other, where each unit may have a rectangular wall surface. Each unit also has a cross section in the shape of a trapezium, the shorter of the two parallel sides facing upwards. The cross-section is preferably sym¬ metrical. Considering a wall of units in the filling direction, it will be seen that at the transition from one unit to the next, there is a volume expansion resulting in expansion of the material flowing down. This volume expansion can be displaced slightly by providing each unit, at least on the inner side, with a downwardly directed, longitudinal tongue or flange so that an air-cushion is formed inside each tongue or flange.

Each unit may be made of solid material.or it may be hollow and made of bent plate(s).

The shape of the unit cross-section thus provides the silo with a stable wall.

Units stacked on top of each other are joined by securing plates arranged at the ends of the units.

Further characteristics of the present invention will be revealed in the following claims.

OM?I The present invention will be described more fully with reference to the accompanying seven drawings (Fig.5 to 8 see page 5), in ωhich

Figure 1 shows a cross-section through a wall element in accordance with the present invention,

Figure 2 . shows how two wall elements are joined together,

Figure 3 shows how walls elements can be joined for different silos, and

Figure 4 shows in part the bottom construction of a silo.

Figure 1 shows a wall element 1 consisting of two units 2A and^" 2B stacked, one on top of the other. The two units have a cross-section in the form of a trapezium said trapezium being symmetrical. Each trapezium consists of three bent, rectangular plates. Two of these three plates have L-shaped cross-section. One of these plates has a side section 3 and top section -4, and the other has a side section 5 and top section 6. These two plates are joined together at the bottom by a rectangular plate bent to give it a U-shaped cross-section. The central section of this plate is designated 7 and constitutes the bottom of the unit 2A. The bent parts of the plate, together with the lower ends of the side sections 3 and 5 , form two longitudinal flanges or tongues 8 and 9. The unit 2B is constructed in exactly the same manner as the unit 2A. A first plate thus has a side section 10 and a top section 11. The second plate has a side section 12 and a top section 13 and the third plate has an intermediate section 1-i , forming the bottom of the unit. Together the three plates form two longi¬ tudinal flanges or tongues designated 15 and 16. The two units 2A and 2B are equal in length and their end surfaces are perpendicular to the longi¬ tudinal direction of the units. Each units is welded at its end to a connecting plate, one of which can be seen and is designated 17. The connecting plate has an intermediate section and two edges bent up, shown clearly in Figure 2. The two units 2A and 2B are welded or secured in any other suitable manner to the intermediate section. In the present case, a wall element comprises two connecting plates and two units. However, it should be evident that each wall element may comprise more than two units, in which case the connecting elements will be as long as the number of units is high.

Two wall elements which are to form a right-angle with each other may be joined in the manner shown in Figure 2. In this figure, the wall element 1 is shown with its connecting plate 17 which has two bent sections 18 and 19- The section 19 is in contact with the bent section of a connecting element 23 for a wall element 22 which is to be at right-angles to the wall element 1. The two adjacent, bent sections of the connecting elements 17 and 23 are joined together by a bolt joint 21. To ensure that the wall elements 1 and 22 assume a stable position, the bent section 18 of the connecting element 17 must be joined to the bent section of the connecting element 23- This is effected by means of a connecting plate 24, secured to the bent sections by means of bolt joints 20 and 25. The connecting element 2- may be eliminated if two more wall elements are to be joined to the two wall elements 1 and 22. Figure 3 shows how silos of varying width can be constructed with the aid of wall elements in accordance with the invention. In this figure several silos are combined to a single unit. However, it should be clear that the various silos 26 - 31 may also be constructed separately without being joined together.

Finally, Figure <4 shows how the bottom 32 of a silo can be arranged in a silo construction comprising wall elements in accordance with the present invention.

A silo in accordance with the present invention functions as follows. If the silo is filled from the top with a slow-running material, this will normally be able to run down one side section 3 since the side section is not too high. A suitable height has been found to be 435 mm. When the slow-running material reaches the lower edge or flange 8 of the unit 2A, the material is relinquished and continues down. Furthermore, the silo becomes wider at the transition from one unit to another in the filling direction, which facilitates the filling process. Naturally the flange 8 may be dispensed with, but the air-cushion formed inside it offers an advantage during filling and such a flange 8 is therefore to be pre¬ ferred.

According to the invention, therefore, slow-running material is saved the necessity of flowing long distances. It need only flow a short distance before being caused to fall some way before starting to flow again.

As can be seen in Figures 5 through 8, elements for constructing silo walls may be composed of four sections, each section being open at the top and the bottom. This offers the advantage of a vertical through-flow of air, thus avoiding moisture problems. Each section is constructed of two strip- like sheets 33 and 34 arranged transversely. The ends of two longitudinal sheets 35 and 40 are secured to the sheets 32 and 34 by means of welding, for instance. The sheet 35 has an outwardly directed flange 36 and an inwardly directed flange 37- The latter flange is provided at its inner edge with a downwardly directed flange 38. In the same way, the sheet 40 is provided with an outwardly directed flange 41 and an inwardly directed flange 42. The inwardly directed flange 42 has a downwardly directed flange 43 at its inner edge. The flanges 42 and 37 are joined together by means of one or more spacers 44. As can be seen in the figures, the sheets 35 and 40 are arranged to constitute the non-parallel sides of the trapezium. The trapezium is open at the top and partially closed at the bottom. The flanges 3 and 38 are designed to be' inserted in the opening 39_} as can be seen in Figure 8 showing a silo wall built of two elements 45 and 46. This is also clear from Figure 7.

OMΓI

Claims

1. Container (26) such as silo for slow-running powder and granular material, characterised in that said container (26) comprises wall elements (1) consisting of stackable units (2A and 2B) having a cross-section in the shape of a preferably symmetrical, open or closed trapezium with the smaller (4 and 6) of the two parallel surfaces (4 and 6,7) facing upwards.

2. Container according to claim 1, characterised in that the stackable units (2A and 2B) are stacked symmetrically.

3. Container according to claim 1, characterised in that each unit (2A and 2B, respectively) is hollow and is in the form of a casing constructed of one or more bent plates (3-7). for instance.

4. Container according to claim 1, characterised in that each unit (2A and 2B, respectively) has end surfaces which are perpendicular to the longitudinal direction of the unit.

5. Container according to one or more of the preceding claims, charac¬ terised in that each unit (2A and 2B, respectively) is provided with a longitudinal, downwardly directed flange or tongue (8 and 9> res¬ pectively) at or close to one or both its lower edges.