| EP0561032A1 | 1993-09-22 | |||
| FR2410226A1 | 1979-06-22 | |||
| FR1564748A | 1969-04-25 |
| Claims
1. Storage tank for liquid, comprising an essentially cylindrical shell wall (2) and an end-wall plate (1) tightly mounted on each of the shell-wall ends, each of the end-wall plates (1) having at least one portion (15) that in a plane normal to an axis extending centrally through the shell wall corbels out past an outer contour of the shell wall (2), characterized in that each end-wall plate (1) has an end-wall plate portion (15) at the same circum ¬ ference positions around the shell (2), that a single-bent substantially rectangular sheet-metal plate (20) shaped as a chute has the parallel edges (21) thereof substantially in contact with the outside of the shell (2) and has the short ends thereof substantially in contact with the end- wall plate portions, the single-bent sheet-metal plate (20) having the edges thereof tightly welded to the shell (2) and the end-wall plate portions, respectively, in order to form a container (25) together with the same, and that a series of openings (40) are recessed through the shell (2) in the area bordering the container (25).
2. Storage tank according to claim 1, characterized in that at least some of the openings (40) have one-way valves (41) having low flow resistance, the valves (41) being directed to prevent liquid flowing through in the direction into the container (25) .
3. Storage tank according to claim 1 or 2, character- ized in that the end walls have a substantially polygonal circumference contour, and have, in a central area, a dome consisting of a deep-drawn end-wall portion, that the border of the dome is fixedly connected to an appurtenant end of a substantially cylindrical tank shell, and that the edges of the end-wall plates are situated at a radial distance outside the border of the dome.
4. Storage tank according to claim 3, characterized in that the plane contour of the end walls is rectangular, preferably square.
5. Storage tank according to any one of claims 1-4, characterized in that the end-wall plates (1) are mutually substantially equal and have a central area (12) that is deep-drawn for the formation of a dome having a substantially cylindrical border part (121) , which is positioned in a lap joint around the outer circumference of the adjacent congruent shell end (21) , and that a fillet weld that extends around the outside of the shell in the transition area between the shell (2) and the respective end wall (1) forms a tight connection between the shell (2) and the end wall (1).
6. Storage tank according to claim 2, characterized in that one of the end-wall plates has a border bending (13) that forms a supporting structure for the storage tank against a support.
7. Storage tank according to claim 6, characterized in that the border bending (13) of the end-wall plate (1) defines a closed annular supporting edge (14), which is situated at or outside the top of the dome (12) , which is turnable from the shell 2.
8. Storage tank according to claim 5 or 6, characterized in that the border bending carries a radially inwardly bent flange 17 at a distance from the adjacent end of the shell 2, which flange extends substantially in a plane nor ¬ mal to the axis of the shell wall 2. |
A storage tank
The invention relates to a storage tank, in particular for a liquid, of the kind that is seen in the preamble of the appended claim 1.
A previously known storage tank of the kind in question comprises an essentially cylindrical shell wall and an end wall tightly mounted on each shell end.
Storage tanks for a liquid are usually produced by butt- welding the circumference border of a dome-shaped end wall arched outward to a respective end of a cylindrical shell wall. In that connection, an additional structure is required in order to stably carry the tank from a plane horizontal support in a chosen orientation, for instance with the cylinder axis oriented vertically. Furthermore, it is difficult to find suitable locations for such a tank, where one or more requisite pipe lead-throughs or accesso ¬ ries such as valves can be mounted easily and safely, since the external surfaces of the tank usually have a substantial curvature. In the centre area of the dome, the curvature of the tank wall is relatively small, and such acces- sories or lead-throughs are usually placed there.
Furthermore, it is not infrequently cumbersome to properly butt-join the end-wall border against the border of the shell for the butt-welding operation.
Furthermore, it is cumbersome and expensive to mount a distribution container along the shell, in order to introduce liquid having a certain temperature from the container on a level in the tank where the corresponding temperature pre- vails. In such applications, the cylinder axis of the tank usually stands vertically and the tank is heat-insulated. When the tank should be used for storage of heat energy,
and when it is desirable to extract as warm a liquid as possible from the tank, it is suitable to place such a container inside or outside the shell wall, there being horizontal passages on different levels between the diffusor container and the tank, so that warm or cold liquid introduced into the container undisturbedly can reach an associated temperature layer in the tank without substantially disturbing the temperature gradient therein. At least in the upper part of the tank, the passages may be provided with one-way valves having a low flow resistance, which allow inflow of liquid from the diffusor into the proper tank.
An object of the invention is to provide a tank, especially a liquid tank, in particular a heat-storage tank, by which one or more of the outlined problems are entirely or partly obviated.
The object is achieved by the invention.
The invention is defined in the appended independent claim 1.
Embodiments of the tank according to the invention are defined in the appended dependent claims.
In the following, the invention will be described by way of examples, reference being made to the appended drawing.
Fig. 1 schematically shows an axial section through a tank.
Fig. 2 shows an enlarged axial section of one of the end portions of the tank.
Fig. 3 shows a detail of the area III in Fig. 1.
Fig. 4 shows a perspective depiction of the end portion of the tank.
Fig. 5 shows a section taken along the line V-V in Fig. 1.
Fig. β illustrates schematically a section taken along the line VI-VI in Fig. 5.
In Fig. 1, a circular-cylindrical shell wall 2 is shown, which at each end is provided with a tightly connected end wall 1. In Figs. 2 and 4, it can be understood that the end wall 1 is formed of a rectangular sheet-metal plate having a central deep drawn area 12 of a cup-shape. The border parts 13 of the sheet-metal plate are turned up 90° from the plane of the sheet-metal plate by a press braking, so that the free ends 14 of the edge parts lie in a common plane, which is parallel to the plane of the starting sheet-metal plate. The convex side of the arched portion 12, which also is called a dome, lies at or below the plane 14. The edge parts 14 form a stiff structure that can carry the contents of the tank and the other parts of the tank, when the end wall 1 in question is placed on a horizontal support, with the centre axis of the shell vertically ori- ented.
Suitably, the two end walls have the same orientation in the circumferential direction, so that their corner portions are axially aligned with each other.
When both end walls contact the support and the axis of the shell accordingly is horizontal, then the end walls, thanks to the polygon shape thereof, can stably carry the tank on the support. Preferably, the end walls are made with a rec- tangular or preferably square circumference contour, but also triangular end walls afford stability to a horizontally oriented tank on a horizontal support, and further-
more the corner areas of the end walls may be utilized in the way mentioned elsewhere herein. The dome should, with a certain margin, be inscribed in the central part of the polygon of the end wall.
In Fig. 3, it can be understood that the arched portion 12 at the circumference thereof has a cylindrical portion 121, the inner wall surface of which has substantially the same diameter as the outer diameter of the shell 2. The portion 121 and the border area 21 of the shell form a lap joint, and an external weld seam 31 is established in the fillet on the outside of the connection area between the end wall 1 and the shell 2. Thanks to the lap joining between the end wall and the shell, the mutual positioning of the same before the welding operation is facilitated.
In, for instance, Fig. 4, it is seen that the corner areas 15 of the end-wall plate 1 between the dome 12 and the edge flanges 14 are flat and extend in a plane normal to the longitudinal axis of the shell, whereby the areas 15 are well suited to afford easy mounting of accessories 16, such as, for instance, valves, pipe lead-throughs and the like. In a further development of the tank, a plate-metal chute 20 is mounted on the outside of the shell 2 between two axially mutually aligned corner areas 15 of the two end walls 1 of the tank. The chute 20 may be regarded to be formed of a substantially rectangular piece of sheet-metal plate, which is single-bent for the formation of a generally U- or V-shaped profile. The profile ends 21 are adja- cent to the outside of the shell 2 and are tightly welded to the same. The length of the chute 20 corresponds to the distance between the mutually facing areas 15 of the two end walls 1. The short ends of the profile are tightly joined and welded to the end walls in the areas 15. Such as is shown in Fig. 5, the chute 15 is preferably dimensioned to be received in the corner areas 15 of the end walls 15. The chute 20 forms, together with the shell wall 2, a con-
tainer 25, which communicates with the interior of the tank volume inside the shell 2 via a series of openings 40 spaced-apart along the axis of the shell 2. In at least some of the openings 40, one-way valves 41 may be arranged, which allow flow from the container 25 into the tank, but prevent liquid flow from the tank to the container 25.
Fig. 6 illustrates furthermore a liquid circuit containing an outlet pipe 61, which via a lead-through 16 extends through the end-wall area 15 into the container 25, and further through the shell wall 2 into an upper area of the tank. Warm water from the upper part of the tank is, via the pipe 61, conducted to a heat consumer 62, from where cooled water is discharged via the pipe section 63, which may extend through the area 15 of the lower end-wall plate 1 into the container 5 and further into the lower part of the tank, such as is shown. A branch pipe 64 from the pipe 63 is shown to extend through a heater 65 and extends through the wall of the chute 20 into the container 25 to a position at the intermediate height area thereof.
The heater 65 may alternatively be placed inside the container 25, for instance in the lower part thereof. One or more of the openings 40, particularly in the lower part of the tank, lack one-way valves to allow outflow of water from the space inside the shell 2 into the container 25.
At at least one of the end walls, each border part 13, at the edge 14 thereof facing away from the adjacent shell, may have a radially inwardly bent flange 17, which then lies substantially in a plane normal to the axis of the shell 2. Said flanges 17 may carry adjustable feet, which carries the storage tank from a possibly uneven support. The flanges 17 may possibly extend along essentially the entire length of the respective edge portion 13. The edge portions 13, as well as also the flanges 17, may be connected to each other, for instance, welded.