Abstract: Radial or axial-radial flow catalytic chemical reactor comprising a cylindrical shell and at least one catalytic bed and comprising a plurality of perforated tubes, said tubes having an open end communicating with an inlet of a gaseous flow of reagents in the reactor, said tubes being provided with a plurality of holes on their side surface, said tubes being arranged around the catalytic bed so as to form an outer wall which bounds the catalytic bed and which distributes the reagents inside said bed; each of said tubes being formed by means of longitudinal or helical butt welding of a perforated strip.

Abstract: Horizontal adiabatic reactor (1) for heterogeneous catalytic reactions, comprising an outer cylindrical shell (2), an inlet (6) for reagent gases and an outlet (7) for gaseous products, a basket (10, 13) containing a catalytic bed (5a, 5b) positioned horizontally inside said reactor, wherein said reactor is configured in such a way that the gases cross said catalytic bed in a radial or axial-radial manner, said shell (2) has a cover (4) which can be opened and which defines an opening (20), and said basket (10, 13) is extractable horizontally from said opening.

Abstract: Radial or axial-radial flow catalytic chemical reactor comprising a cylindrical shell and at least one catalytic bed and comprising a plurality of perforated tubes, said tubes having an open end communicating with an inlet of a gaseous flow of reagents in the reactor, said tubes being provided with a plurality of holes on their side surface, said tubes being arranged around the catalytic bed so as to form an outer wall which bounds the catalytic bed and which distributes the reagents inside said bed; each of said tubes being formed by means of longitudinal or helical butt welding of a perforated strip.

Abstract: Horizontal adiabatic reactor (1) for heterogeneous catalytic reactions, comprising an outer cylindrical shell (2), an inlet (6) for reagent gases and an outlet (7) for gaseous products, a basket (10, 13) containing a catalytic bed (5a, 5b) positioned horizontally inside said reactor, wherein said reactor is configured in such a way that the gases cross said catalytic bed in a radial or axial-radial manner, said shell (2) has a cover (4) which can be opened and which defines an opening (20), and said basket (10, 13) is extractable horizontally from said opening.

Abstract: Method for modifying a hot wall ammonia reactor con vessel (2) having partial opening, comprising: assembly directly inside the vessel (2) of a catalytic cartridge (7) with modular elements, said modular elements being of a size compatible with introduction into the vessel through a pre-existing partial opening (6) of the vessel, and each comprising at least one panel (11); the panels (11) of said modular elements forming a substantially cylindrical outer wall (7a) of said cartridge (7), and an annular flux space (8) between said outer wall of the cartridge and an inner wall of the vessel; said panels (11) being provided with a respective heat insulation layer (13) before introduction into the vessel (2).

Abstract: A system (8; 9; 50) is described of walls for catalytic beds of synthesis reactors (1), in which there is a wall (14) in direct contact with a catalytic bed (7) for containing it, said wall (14) having a plurality of portions (17) permeable to the gases and a plurality of portions (19; 54; 55) impermeable to the gases, said portions (17) permeable to the gases being equipped with slits (18; 52, 53; 60; 70) of a size such as to allow the free passage of the synthesis gases through them but not the passage of the catalyst, in which the slits are obtained with milling, water cutting or electro-erosion processing.

Abstract: A chemical isothermal reactor (1) with internal plate heat exchanger (10) having heat-exchange radial plates (11), and radial ducts (14, 15) parallel to sides (13i, 13s) of the plates (11) for distributing and collecting a heat exchange fluid, said radial ducts having a portion with a smaller cross section near the inner converging ends (14c, 15c).

Abstract: A steam cooled chemical reactor (1) comprising a vertical vessel (2), a plate heat exchanger embedded in a catalytic bed, to cool the catalytic bed by evaporation of a cooling water flow, wherein a water inlet and a steam outlet are located underneath the heat exchanger, and the plates and related piping are arranged so that the path of the cooling flow comprises a first ascending path from bottom to top of the catalytic bed, and a second descending path from top to the bottom of catalytic bed, and wherein internal evaporation channels of the plates provide the second descending or the first ascending path, and water upcomers or respectively steam downcomers provide the other of said first and second path.

Abstract: A radial-flow plate heat exchanger (5) embedded in the catalytic bed of an isothermal chemical reactor (1) has heat exchange plates (10) comprising fluid passages (13) between a first metal sheet (20) and a second metal sheet (21) joined by perimeter weld seams (23) on a first surface (A) of the plate, a feeding channel (14) and a collecting channel (15) for the heat exchange fluid are formed with suitable metal sheets which are seam welded (25) directly to the opposite surface (B) of the plate, this structure allows the manufacturing of the plate (10) with an automated seam welding process, such as laser beam welding.

Abstract: Plant for urea production from ammonia and carbon dioxide having a so-called high-pressure section which comprises a synthesis reactor and a condensation unit (7, 107) positioned inside the reactor, all substantially operating at the same pressure.

Abstract: A tube isothermal chemical reactor (1), comprising a vessel (2) with a central axis (A-A), and an annular tube heat exchanger (40) embedded in a catalytic reaction space, the exchanger (40) comprising a plurality of concentric ranks (10, 11) of tube packs (10a), each of said tube packs comprising parallel tubes (30), a respective heat-exchange fluid feeder (20) and a respective heat-exchange fluid collector (21).

Abstract: System for supporting a plate heat exchanger (10, 100, 200) inside an isothermal chemical reactor (1), comprising a circumferential ring structure (40) fixed at least to top radial sides (19s) of the plates (11), said structure being formed as a single or double ring.

Abstract: A system (8; 9; 50) is described of walls for catalytic beds of synthesis reactors (1), in which there is a wall (14) in direct contact with a catalytic bed (7) for containing it, said wall (14) having a plurality of portions (17) permeable to the gases and a plurality of portions (19; 54; 55) impermeable to the gases, said portions (17) permeable to the gases being equipped with slits (18; 52, 53; 60; 70) of a size such as to allow the free passage of the synthesis gases through them but not the passage of the catalyst, in which the slits are obtained with milling, water cutting or electro-erosion processing.

Abstract: Method and apparatus for carrying out highly exothermic catalyzed reactions, like so-called oxidative reactions, in pseudo-isothermal conditions, for example the reaction for producing nitric acid and the reaction for producing formaldehyde.

Abstract: An internal start-up heater (10) for an ammonia reactor (1), comprising longitudinal heating members (16) and a supporting structure for said heating members (16), the structure comprising plates (20A-20D) with parallel beams (22A-22D) in contact with said heating members (16), wherein the plates are arranged in plate sets formed by at least a first and a second plate having differently arranged supporting beams.

Abstract: An isothermal chemical reactor (1) comprising an array of radially arranged plate-like heat exchange elements (11) inside a reaction space, each element comprising feeding and collecting ducts and a bundle of parallel tubes (15) defining channels (12) for a heat exchange medium, the tubes (15) having an elongated cross section and being disposed with a variable orientation relative to the radial direction of the reactor, so that inner tubes near the axis of the reactor have the cross-section major axis aligned with said radial direction, and outer tubes have the same axis perpendicular to the radial direction. The preferred structure of a plate-like heat exchange element is also disclosed.

Abstract: A system (8; 9; 50) is described of walls for catalytic beds of synthesis reactors (1), in which there is a wall (14) in direct contact with a catalytic bed (7) for containing it, said wall (14) having a plurality of portions (17) permeable to the gases and a plurality of portions (19; 54; 55) impermeable to the gases, said portions (17) permeable to the gases being equipped with slits (18; 52, 53; 60; 70) of a size such as to allow the free passage of the synthesis gases through them but not the passage of the catalyst, in which the slits are obtained with milling, water cutting or electro-erosion processing.

Abstract: Isothermal vertical reactor (1) for a chemical reaction, comprising a shell (2) with internal gas-permeable walls (16, 18) defining an inlet distribution chamber (17) and a product collecting chamber (19), an open-top catalytic bed between said gas-permeable walls, and a tube heat exchanger (5) embedded in said catalytic bed, the tube heat exchanger (5) comprising a bundle of U-tubes, where an inlet (14) is disposed to direct a fresh charge in an upper chamber (21) over the catalytic bed and the U-shaped top portion of the tube bundle; a portion (F1) of the fresh charge passes through the catalytic bed with a mixed axial-transversal flow, and another portion (F2) of the fresh charge enters the inlet gas-distribution chamber (17) and passes through the catalytic bed with a substantially transversal flow.

Abstract: A steam cooled chemical reactor (1) comprising a vertical vessel (2), a plate heat exchanger embedded in a catalytic bed, to cool the catalytic bed by evaporation of a cooling water flow, wherein a water inlet and a steam outlet are located underneath the heat exchanger, and the plates and related piping are arranged so that the path of the cooling flow comprises a first ascending path from bottom to top of the catalytic bed, and a second descending path from top to the bottom of catalytic bed, and wherein internal evaporation channels of the plates provide the second descending or the first ascending path, and water upcomers or respectively steam downcomers provide the other of said first and second path.

Abstract: Method for modifying a hot wall ammonia reactor con vessel (2) having partial opening, comprising: assembly directly inside the vessel (2) of a catalytic cartridge (7) with modular elements, said modular elements being of a size compatible with introduction into the vessel through a pre-existing partial opening (6) of the vessel, and each comprising at least one panel (11); the panels (11) of said modular elements forming a substantially cylindrical outer wall (7a) of said cartridge (7), and an annular flux space (8) between said outer wall of the cartridge and an inner wall of the vessel; said panels (11) being provided with a respective heat insulation layer (13) before introduction into the vessel (2).