US3761067A - Large-size metal-framed tower - Google Patents

Abstract

A large size metal frame cooling tower of generally upright cylindrical configuration has an outer surface of metal frame work or panels. At least one stiffening ring is provided either on the inside or the outside of the cylindrical structure, or both. A crane may orbit the tower on one of the stiffening ring structures.

Description

United States Patent 1 Marosi et al.

1 LARGE-SIZE METAL-FRAMED TOWER [75] Inventors: Istvan Marosi; Frigyes Volgyes, both of Budapest, Hungary Ipari Epulettervezo Vallalat, Budapest, Hungary Filed: Apr. 15,1971

Appl. No.: 134,368

Assignee:

Int. Cl E04g 11/04, BOlf 3/04 Field of Search 261/DIG. 11, 111; 212/57, 64; 52/245, 246

References Cited UNITED STATES, PATENTS 10/1951 Pennington 52/245 8/1966 Kalupin et a1. 52/245 US. Cl 261/111, 26l/DIG. 11, 212/57, I

Primary ExaminerTim R. Miles Assistant Examiner-Steven H. Markowitz Attorney-Young & Thompson [57] ABSTRACT A large size metal frame cooling tower of generally upright cylindrical configuration has an outer surface of metal frame work or panelsuAt least one stiffening ring is provided either on the inside or the outside of the cylindrical structure, or both. A crane may orbit the tower on one of the stiffening ring structures.

5 Claims, 3 Drawing Figures LARGE-SIZE METAL-FRAMED TOWER The invention relates to large-size. metal-framed towers, especially to cooling towers having a mantlesurface of circular cylinder-jacket shape.

According to the technical literature, cooling towers are built on the basis of established design principles. One type of the known construction of such character is the steelwork cooling tower the shape of which may be cylindrical, frusto-conical type, prism of polygonal floor plane, possibly some body of rotation, etc.

The above mentioned formations determine the suitable building technology but experience has shown that the construction of such towers always requires the use of huge-size tower cranes of appropriate load-bearing capacity, being owing to the generally extraordinary height of the construction different from the conventional. This, however, is a drawback since the production, transport and assembly of such especially large-size tower cranes are expensive and complicated. Moreover, the building of cooling towers at large distances and possibly at intervals of several years does not render possible the rational and economic utilization of such huge tower cranes.

Considering now the statical development and force distribution of the tower constructions, owing to the great forces resulting in the first place from the wind load, large-size cooling towers are subject to considerable stresses and to deformations exceeding those usual in engineering practice. Therefore, such constructions can be designed only of profiles of large cross-section, with excessively high material requirements, that is, uneconomically. In addition, the constructions with high material requirements need larger, more expensive and more complicated foundation works, resulting in further rise of the investment costs.

The invention aims at a structural design for largesize metal-framed towers, especially cooling towers, having a mantle surface of circular cylinder-jacket shape which due to its configuration renders unnecessary the useof expensive and unutilized tower cranes on the one hand, and provides for a high rigidity as compared to conventional constructions on the other. Hence, tower construction can be realized with a considerably smaller material consumption, i.e. more economically, than the constructions known hitherto.

In accordance with this object, according to the invention, large-size metal-framed towers especially cooling towers with mantle surface of circular cylinderjacket shape are designed so that the mantle surface is developed as a metal framework or made of panels, and along the mantle surface outside and/or inside at least one stiffening ring participating in the force distribution of the mantle surface and at the same time serving as an auxiliary assembly element is arranged.

A further characteristic of the construction according to the invention consists in that the mantle of the tower can be a cylinder or body of rotation of optional directrix and of straight, polygonal or optionally curved generatrix.

The stiffening rings are preferably ring or discshaped planar girders of high rigidity, the plane of which is perpendicular to the generatrix of the mantle surface.

In another solution, the stiffening rings may be ringor disc-shaped girders, the plane of which encloses an angle with the generatrix of the mantle surface.

The stiffening rings are provided with a positive guide for the circumvolution of a crane mechanism and lift ing means for moving the stiffening rings are fastened to the mantle surface of the tower, preferably to its current highest level. i

The large-size metal-framed towers according to the invention have severaladvantageous properties in comparison to the constructions of similar purpose known hitherto. One of the most important thereof is that the proposed construction combines the advantages of spatial lattice girders and shell structures. This means that the force distribution of the tower according to the invention is similar to that of the shell structure, consequently it is highly economical as to material requirement and at the same time, of the same rigidity as the spatial lattice girders.

Another design factor should also be mentioned here, namely that with the shell structures the secondary effects i.e. that the deformations occurring under the effect of loads react on the force distribution of the structure are usually not taken into consideration owing to their complexity (that is, they are taken into consideration only when using a computer). These so-called secondary effects, however, can be very considerable. In the case of the construction proposed by the invention, on the contrary, these secondary effects are very low, and are negligible. The main reason therefor is that the stiffening rings participate in the force distribution of the mantle surface.

The comparative examinations carried out from the point of view of the material consumption show that in case of for instance a cone-mantle shaped tower the steel used according to the invention amounts to only about 50 per cent of the conventional amount and the static stresses occurring in the foundation are only about one-eighth of those occurring with constructions without stiffening rings. Similar comparisons were made in the case of a tower designed with a hyperbolic mantle surface and a similarly considerable material saving of about 30 per cent was observed in favour of the construction proposed by the invention.

The invention is explained by means of the accompanying drawing by way of examples, where FIG. 1 shows the half longitudinal section of the large-size metal-framed tower according to the invention,

FIG. 2 is the half side-view of the tower mantle,

FIG. 3 indicates the longitudinal section of the tower construction shown so that in the left side of the drawing a horizontal section taken in the plane of the inner stiffening ring is represented, whereas in the right side of the drawing that taken in the plane of the ground level is shown.

In FIG. 1 the mantle l of the tower construction is schematically shown which is in the given case composed of panels but may be constructed also of lattice girders. On the inside of the mantle surface 1 there is the inner stifiening ring 2, and on its outer side, the outer stiffening ring 3. Such stiffening rings may be ap' plied along the mantle surface of the tower in optional number, arrangement and division. The stiffening rings may be located alternately at the inside and outside, and it is possible, too, to provide either exclusively outer stiffening rings or exclusively inner ones and there is no objection at all to making the inner and outer stiffening rings in irregular succession.

These stiffening rings participate in the force distribution of the mantle surface when the construction is properly used, and play already an important part during the mounting operation. The use of these stiffening rings renders possible the building of the complete construction without any tower crane. The stifiening rings are expediently developed as lattice girders of horizontal plane, provided with a positive guide 4 which permits the movement of some light and simple erecting crane.

By means of the said erecting crane not shown in the drawing the panel elements 5 may be lifted from the ground and located in the following level of the mantle surface of the tower. The complete new level made of panel elements 5 being finished, the stiffening ring may be lifted to the uppermost level by means of some appropriate lifting device, for instance of winch and hoist, or of hydraulic lifting system.

The tower construction can be made of commercially used mild steel, of high-tensile steel or of suitably chosen aluminum alloy. The elements of the construction can be developed not only of panel elements 5 but asshown in FIG. 2 as simple metal frameworks 6. The structural elements can be interconnected by any structural joint known by itself.

What We claim is:

l. A large size metal frame cooling tower in the form of a hollow upright cylinder of metal framework, at least one stiffening ring concentric with the tower, and a plurality of structural elements extending from the stiffening ring diagonally downwardly and connected to the tower at a level lower than the stiffening ring, the space along the tower above and below at least one said ring being free said ring having a horizontal guide on its upper surface for an erecting crane.

2. A tower as claimed in claim 1, and structural elements extending diagonally upwardly from the stifiening ring and secured to the tower. I

3. A cooling tower as claimed in claim 1, there being a plurality of said rings vertically spaced apart along the height of the tower.

4. A tower as claimed in claim 3, one of said rings being disposed inside the tower and another of said rings being disposed outside the tower.

5. A tower as claimed in claim 4, said another ring being disposed lower than said one ring, and structural framework extending diagonally outwardly and downwardly from said another ring into supporting engagement with the ground at a distance outside the lower end of said tower.

Claims (5)

1. A large size metal frame cooling tower in the form of a hollow upright cylinder of metal framework, at least one stiffening ring concentric with the tower, and a plurality of structural elements extending from the stiffening ring diagonally downwardly and connected to the tower at a level lower than the stiffening ring, the space along the tower above and below at least one said ring being free said ring having a horizontal guide on its upper surface for an erecting crane.

2. A tower as claimed in claim 1, and structural elements extending diagonally upwardly from the stiffening ring and secured to the tower.

3. A cooling tower as claimed in claim 1, there being a plurality of said rings vertically spaced apart along the height of the tower.

4. A tower as claimed in claim 3, one of said rings being disposed inside the tower and another of said rings being disposed outside the tower.

5. A tower as claimed in claim 4, said another ring being disposed lower than said one ring, and structural framework extending diagonally outwardly and downwardly from said another ring into supporting engagement with the ground at a distance outside the lower end of said tower.

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