Abstract:
Tube-bundle equipment for heat exchange operations at high pressures and temperatures, under conditions of high aggressiveness of the process fluids, comprising a titanium lining (11) and a series of tubes (1) consisting of at least one layer of zirconium (2), positioned in contact with said fluids, wherein the tube plate on which said tubes are inserted comprises an outer layer (S) of zirconium or an alloy thereof and an underlying layer (5) of titanium welded to the lining of the equipment. Said equipment is particularly used as a heat exchanger, for example as a stripper, in the high-pressure cycle of urea syntheses processes.
Abstract:
A gripper for selectively gripping continuous elongated members can include a tubular supporting structure extending along a given axis and designed to surround a continuous elongated member. The gripper can also include at least two inflatable bags within the tubular structure and in the shape of complementary cylindrical sectors.
Abstract:
A lay ramp for an underwater-pipeline laying vessel has an inside ramp hinged to the laying vessel; an outside ramp hinged to the inside ramp; and an actuating device having a first actuating assembly for rotating the inside ramp with respect to the laying vessel, and a second actuating assembly secured to the outside ramp and to the first actuating assembly to rotate the outside ramp with respect to the inside ramp.
Abstract:
A method of joining two portions of an underwater pipeline laid on the bed of a body of water to conduct fluid and/or gas, the method including: joining a telescopic sleeve, having a first coupling head, to a first end of a first pipeline portion above the body of water; laying the first end, the telescopic sleeve, and the first coupling head on the bed of the body of water; joining a second coupling head to a second end of a second pipeline portion above the body of water; laying the second end and the second coupling head on the bed of the body of water, close to the first coupling head; roughly aligning the first and second coupling head in the body of water; and clamping the first and second coupling head to each other in the body of water.
Abstract:
Tube-bundle equipment of the falling liquid film type, comprising a vertical cylindrical body closed at the ends and divided into at least an upper section, an intermediate section and a lower section by means of two perforated tube sheets arranged transversally to support the tubes forming the bundle, wherein each of said tubes is surmounted, on the upper end, by a ferrule, for the inlet and distribution of the liquid in the form of a film, which comprises in the upper part, one or more openings for the outlet of vapours, at an intermediate height one or more openings, preferably tangential, for the inlet of the liquid and below, a circular base for resting on said tube from which an internal cylindrical section, inserted in the tube for a length varying from 10 to 200 mm, protrudes downwards together with an outer metallic strip for a length of at least 2 mm, so that, in the circular area defined between said outer metallic strip and said protruding cylindrical section, there is a gasket, inserted between said circular base of the ferrule and said upper edge of the tube.
Abstract:
A pipe-laying vessel (1) is provided, including a tower (2) extending upwardly from the vessel, a pipe loading arm (9) for raising a length of pipe from the deck to a position aligned with the tower. The pipe-laying vessel may also include a support assembly (110) for supporting a bulky item to be accommodated along the pipeline, the support assembly including a frame (111) pivotable between a first load receiving position and a second tilted position in which it extends approximately parallel to the tower, and drive means for pivoting the tiltable frame between its first and second positions. The pipe-laying vessel may alternatively or additionally include a welding assembly station cabin (100) in the region of a lower portion of the tower, a movable support assembly (110) for supporting a bulky item to be accommodated along the pipeline, the movable support assembly being disposed on top of the cabin.
Abstract:
A process for the recovery of ammonia contained in a gaseous stream is described, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing (S) with an aqueous washing solution (5a) having a pH lower than 7.0, with the formation of a purified gaseous stream (6) and an aqueous solution (7) containing an ammonium salt; (b) subjecting the aqueous solution containing the ammonium salt coming from phase (a) to a distillation process (MD) with a hydrophobic microporous membrane at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 4 MPa absolute with the formation of a regenerated washing solution (16) and a gaseous stream (18) comprising NH3 and H2O; (c) recycling said generated washing solution to phase (a). The equipment for carrying out the above process is also described.
Abstract:
An enhanced process is described for the synthesis of urea from ammonia and carbon dioxide, at a high pressure and temperature, with the formation of ammonium carbamate as intermediate, which includes a high pressure synthesis section, comprising at least one separation step by decomposition-stripping with ammonia of the non-converted ammonium carbamate, carried out in a vertical apparatus, commonly called stripper, characterized in that said step also comprises a feeding, in the lower part of said stripper, of a stream of CO2, heated to a temperature ranging from 130 to 230° C., in a quantity of 1 to 15% by weight with respect to the total weight of the fresh CO2 fed to the process, containing a passivating agent in such a quantity that its equivalent content of O2 in moles varies from 0.05% to 0.80% with respect to the moles of CO2 of said stream.
Abstract:
A process is described for obtaining high-purity 1-butene starting from C4 hydrocarbon mixtures containing isobutene, n-butane, isobutane, 1,3-butadiene, 1-butene, 2-butenes and also optionally C3 and C5 hydrocarbons, comprising the following stages: conversion of isobutene effected in a double stage, wherein each stage consists of one or more reactors followed by a distillation column for the recovery of the reaction product; recovery of the excess alcohol; recovery of 1-butene using at least two distillation columns; characterised in that it also uses a further conversion stage, consisting of one or more reactors in series, for completing the isobutene removal.
Abstract:
A method of joining pipes (3) to produce underwater pipelines (2), wherein the facing free ends (15) of two adjacent pipes (3), aligned along an axis (A), are welded to define a cutback (18); a protective sheet (22) of plastic material is extruded close to the cutback (18); and the protective sheet (22) is wound about the cutback (18).