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United States Patent m
[ii] Patent Number: 4,541,990  Date of Patent: Sep. 17, 1985
 Inventor: Paul Mitterbacher, Gallneukirchen, Austria
 Assignee: Voest-Alpine Aktiengesellschaft, Austria
 Appl. No.: 556,564
 Filed: Nov. 30, 1983
 Foreign Application Priority Data
Dec. 2, 1982 [AT] Austria 4380/82
 Int. Q." B01J 19/02
 U.S. CI. 422/242; 422/241
 Field of Search 422/189, 193, 194, 232,
422/233, 241, 242
 References Cited
U.S. PATENT DOCUMENTS
2,181,153 11/1939 Prickett 422/241
3,172,832 3/1965 Dreyer et al 208/47
3,235,344 2/1966 Dreyer et al 422/242
FOREIGN PATENT DOCUMENTS
1230953 12/1966 Fed. Rep. of Germany .
1258003 1/1968 Fed. Rep. of Germany .
2503511 8/1976 Fed. Rep. of Germany .
Primary Examiner—John Adee
Attorney, Agent, or Firm—Burns, Doane, Swecker &
A vessel includes an outer wall and an inner wall arranged at a distance therefrom within the vessel and leaving an annular space relative to the outer wall. The inner wall is supported on the outer wall so as to allow for relative movements. In order to provide a vessel with which the danger of oscillations of the inner wall is avoided, with which a simple supply of medium is possible, which is easy to clean and with which the danger of an implosion of the inner wall is reduced, the inner wall is comprised of individual annular sections subsequently arranged in an axial direction of the vessel. Each section is supported on the outer wall independently of the other sections. An expansion joint is provided between two neighboring annular sections each.
16 Claims, 5 Drawing Figures
U.S. Patent Sep. 17,1985 Sheet2 of2 4,541,990
The present invention relates to a vessel, in particular a pressure vessel for hydration or cracking plants, com- 5 prising an outer wall, optionally provided with an inner lining, and an inner wall arranged at a distance therefrom within the vessel and leaving an annular space relative to the outer wall, the inner wall being supported on the outer wall so as to allow for relative 10 movements.
Vessels with inner walls (also called liners) are used, for instance for hydration and cracking plants, being under a high pressure (about 300 bars) in such plants and having process temperatures of about 500° C. in 15 their interiors. By providing an inner wall, a temperature decrease of the pressure-bearing outer wall is achieved due to the formation of a stationary medium layer in the annular space between the outer wall and the inner wall. Furthermore, the outer wall is protected 20 by the inner wall against depositions (such as, for instance, petrol coke or cracked tar, as they form during hydration) and in case of local damage to the isolating layer.
It is known to design the inner walls in one part and 25 inherently rigid and to support or fasten them on one point only, for instance on one end of the vessel, so that the inner wall may expand freely to the opposite end of the vessel. This mode of construction has the disadvantage that a relatively large expansion gap must be pres- 30 ent between the movable end of the inner wall and the pertaining end of the vessel. Furthermore, the known inner wall cannot be supported laterally on account of the radial thermal expansion, thus risking an oscillation of the inner wall. 35
A further problem arises, if one attempts to introduce a medium into the vessel between the vessel ends. For, one is then forced to either lead also through the inner wall pipe sockets laid laterally through the pressurebearing outer wall, with the pipe sockets being guided 40 through longholes of the inner wall extending in the axial direction of the vessel, in order to enable an axial expansion of the inner wall relative to the outer wall, or to introduce pipes into the vessel by departing from a bottom of the pressure vessel, which pipes project into 45 the vessel in the axial direction as far as to the site at which the medium is to be supplied. If this site is, for instance, in the center of the vessel, one is forced to arrange very long pipes within the vessel, which is disadvantageous when cleaning the vessel and calls for 50 special measures to support these long pipes. In case of laterally introduced pipe sockets, depositions at and behind the longholes of the inner wall, which are penetrated by the pipe sockets, will be caused.
A further problem of known inner walls in pressure 55 vessels will arise if the pressure vessel is shut down extremely quickly or at a sudden, for instance, in case of a failure. As a consequence, there is the danger of implosions of the inner wall.
The invention aims at avoiding these disadvantages 60 and difficulties and has as its object to provide a vessel of the initially defined kind, with which the danger of oscillations of the inner wall is avoided, with which a simple supply of medium is possible, which is easy to clean and with which the danger of an implosion of the 65 inner wall is reduced.
This object is achieved according to the invention in that the inner wall is comprised of individual annular
sections subsequently arranged in an axial direction of the vessel, each section being supported on the outer wall independently of the other sections and an expansion joint being provided between two neighboring annular sections each.
With a vessel having a cylindrical vessel part, the inner wall in the cylindrical vessel part suitably is comprised of neighboring cylindrical courses constituting the sections, each cylindrical course being movably supported on the outer wall by means of at least three guides radially extending from the axis of the vessel.
According to a preferred embodiment, the inner wall comprises frustoconical or spherical-segment-shaped courses neighboring the vessel bottoms of the vessel, which, with their ends having the larger diameters, are each directed to the cylindrical courses and, with their ends having the smaller diameters, are each directed to the vessel bottoms.
Therein, a frustoconical or spherical-segment-shaped course suitably is supported on the vessel bottom by means of supports extending in the direction of the axis of the vessel at about half the height of the course or thereabove, measured from the end having the smaller diameter. By the support at half height or thereabove, the frustoconical courses may freely expand axially in both directions, the radial expansion of the frustoconical courses being enabled by a slight bow of the guides extending in the axial direction.
A particularly simple installation of the inner wall is feasible if the courses are formed by parts neighboring in the peripheral direction, which are connected by seams extending in the longitudinal direction of the vessel. Thereby it is possible to introduce the parts of the courses through the manhole into the vessel; a vessel lid extending over the total cross section of the vessel may be omitted.
Suitably, the guides are formed by pipings penetrating the outer wall, into which project, or which project into, pipe sockets mounted on the courses and penetrating these courses, with play, whereby one structural part, i.e., the guide, assumes three functions: it serves to support and to center the courses and, in addition, to supply medium. The pipe sockets penetrating the courses may be sealed relative to the inner wall and need not project beyond the inner wall. Thereby it is possible to achieve a smooth inner wall surface, which is responsible for an undisturbed flow in the interior of the vessel and which permits an easy and simple cleaning of the inner space. Furthermore, depositions in the annular space provided between the inner wall and the outer wall are prevented.
According to a preferred embodiment, the courses on that end which is more closely neighboring to the vessel bottom draining the medium are each provided with a radially inwardly offset step ring reaching beyond the neighboring course in the direction of the vessel axis, whereby flows in the annular space between the inner wall and the pressure-bearing outer wall are reliably prevented and the courses are also guided at each other.
Preferably, neighboring courses are connected by means of flexible sieve rings bridging the expansion joints, whereby the penetration of solids into the annular space is effectively prevented, while displacements between the courses due to thermal expansions are not impeded.
Furthermore, it is suitable if supports projecting towards the courses are fastened to the outer wall, surrounding the courses with a radial play. The supports