Abstract: Catalytic chemical reactor comprising a perforated wall (6) adjacent to a supporting wall of the reactor or of a catalytic cartridge contained in the reactor, wherein said perforated wall comprises a plurality of panels (7) and comprises first sectors (9) resting on the supporting wall and second sectors (10) spaced from said supporting wall defining a cavity (11), and wherein means are provided for local securing said gas-permeable wall to said supporting wall, said securing means comprising: a plurality of support elements (13) fixed to the supporting wall (4) and passing through respective openings (15) of the first sectors (9) of the gas-permeable wall and a respective plurality of locking elements (14) which can be associated with the said support elements, the panels of the gas-permeable wall being gripped between said supporting wall and said locking elements.

Abstract: Shell and tube heat exchanger (1) comprising a first outer shell (2) and a tube bundle (3), inlet and outlet interfaces communicating with the shell side and with the tube side for a first fluid and for a second fluid respectively, wherein the exchanger comprises a second shell (4) which is inside said first shell (2) and surrounds said tube bundle (3); said second shell (4) comprises at least one releasable longitudinal joint (32) and a plurality of longitudinal sections connected by releasable joints; said second shell (4) delimits the shell side of the exchanger (1) around said tube bundle (3), and further defines a flushing interspace (5) communicating with said shell side, said first fluid flows through said shell side along one or more longitudinal passages, and said first fluid and said second fluid are counter-current along said one or more longitudinal passages.

Abstract: Catalytic chemical reactor comprising a perforated wall (6) adjacent to a supporting wall of the reactor or of a catalytic cartridge contained in the reactor, wherein said perforated wall comprises a plurality of panels (7) and comprises first sectors (9) resting on the supporting wall and second sectors (10) spaced from said supporting wall defining a cavity (11), and wherein means are provided for local securing said gas-permeable wall to said supporting wall, said securing means comprising: a plurality of support elements (13) fixed to the supporting wall (4) and passing through respective openings (15) of the first sectors (9) of the gas-permeable wall and a respective plurality of locking elements (14) which can be associated with the said support elements, the panels of the gas-permeable wall being gripped between said supporting wall and said locking elements.

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: Vertical reactor (1) for chemical reactions, comprising a tube heat exchanger (6) immersed in a catalytic bed (5), wherein said tube exchanger (6) comprises a plurality of straight tube bundles (6.1, 6.2) with respective tube plates for feeding (9.1, 9.2) and collecting (10.1, 10.2) the heat exchange fluid, and wherein the tube bundles and the respective tube plates are vertically staggered so as to allow access to the shell side.

Abstract: Combined apparatus (1) for the synthesis of urea from ammonia and carbon dioxide, comprising an internal wall (3) which delimits two coaxial zones (4) inside the apparatus, operating respectively as reaction (4) and condensation (5) zones, and optionally also comprising a stripping zone and/or a scrubber integrated in the same apparatus.

Abstract: Reactor for the synthesis of melamine from urea, in accordance with the high-pressure non-catalytic process, comprising: a vertical reactor body (1), at least one inlet (2) for the urea melt, a set of heating elements (3), and a central duct (7), said set of heating elements (3) being arranged inside said central duct.

Abstract: Reactor (1) for catalytic chemical reactions, comprising: a partially open outer vessel (2) comprising a manhole (6) for accessing to the interior, and at least one internal wall (5) comprising a plurality of panels (5.1, 5.2, . . . 5.n) assembled inside the vessel (2) so as to form said wall (5); the panels are flexible and deformable so that they may be inserted through said manhole (6), and the resulting wall (5) is not self-supporting and rests against a load-bearing wall (7) of the reactor.

Abstract: Reactor (1) for catalytic chemical reactions, comprising: a partially open outer vessel (2) comprising a manhole (6) for accessing to the interior, and at least one internal wall (5) comprising a plurality of panels (5.1, 5.2, . . . 5.n) assembled inside the vessel (2) so as to form said wall (5); the panels are flexible and deformable so that they may be inserted through said manhole (6), and the resulting wall (5) is not self-supporting and rests against a load-bearing wall (7) of the reactor.

Abstract: Tube-bundle heat exchange unit (1) for internals of heat exchangers or reactors, comprising: at least one tube bundle (2); a plurality of baffles (3) associated with said tube bundle and defining through-openings according to a predefined arrangement, each opening being passed through by one of more tubes of the tube bundle, and a shell (6) which surrounds said tube bundle and said baffles, wherein the assembly of the tube bundle and the shell can be disassembled and the shell is structurally collaborating with the tube bundle through said baffles.

Abstract: Shell-and-tube equipment comprising baffles (5) supporting the tubes, each baffle (5) having seats for receiving the tubes shaped so as to receive one or more tubes in at least one free play condition and in a locking condition; each baffle (5) is displaceable with respect to the tube bundle between an assembly position and a working position; in the assembly position the tubes can be received by the baffles in the free play condition while in the working position the tubes are locked; a respective method of assembling the tube bundle and the baffles is also described.

Abstract: Horizontal reactor (1) for catalytic reactions, comprising an outer cylindrical shell (2), a catalytic bed (5) and heat exchange plates (6) immersed in said catalytic bed, parallel to each other and supplied with a heat exchange fluid; said reactor comprises a container (7) for said catalytic bed (5) and said plates (6), said container is extractable slidably from said shell, by means of at least one linear guide (31, 32, 45) extended longitudinally with respect to said shell (2).

Abstract: Reactor for the synthesis of melamine from urea, in accordance with the high-pressure non-catalytic process, comprising: a vertical reactor body (1), at least one inlet (2) for the urea melt, a set of heating elements (3), and a central duct (7), said set of heating elements (3) being arranged inside said central duct.

Abstract: A reactor and associated process for the high-pressure synthesis of melamine from urea, comprising a primary step of conversion of the urea into crude melamine inside a first chamber delimited by a shell inside a reactor body and a secondary step of stripping said crude melamine melt inside a second reaction chamber, which is coaxial with and situated outside said first chamber, inside the same reactor body.

Abstract: Heat exchanger comprising a tube bundle (1) and a shell (2) which surrounds said tube bundle, said tube bundle comprising tubes (3) arranged with a square or triangular pitch, wherein said shell (2) has a cross-section, in a plane perpendicular to said tubes, having the form of an irregular polygon; said irregular cross-sectional polygon has a number of sides which is a multiple of three or multiple of four for tube bundles with a triangular or square pitch, respectively; the sides of said cross-sectional polygon are parallel to the directional lines of the tubes.

Abstract: Process and respective reactor for urea or melamine synthesis, comprising sonication treatment of at least part of a reaction liquid mass or two-phase mixture contained inside said reactor.

Abstract: Plate heat exchanger for internals of isothermal chemical reactors, said plate heat exchanger comprising a plurality of heat exchange plates (1) having an essentially rectangular shape, wherein each plate comprises two walls (2, 3) which are joined together along their perimeter, and wherein each plate comprises a respective first collector for feeding a heat exchange medium to the plate and a respective second collector for receiving said medium form the plate, said first collector and second collector being fixed to opposite sides of said plate, and at least one (10, 30) of said first collector and second collector comprises edge surfaces which are planar and parallel to respective planar end portions (12, 13) of said plate, to provide plane and parallel surfaces for automated welding.

Abstract: Reactor for the synthesis of melamine from urea, in accordance with the high-pressure non-catalytic process, comprising: a vertical reactor body (1), at least one inlet (2) for the urea melt, a set of heating elements (3), and a central duct (7), said set of heating elements (3) being arranged inside said central duct.

Abstract: Apparatus for prilling a liquid, comprising a distributor for supplying said liquid, at least one dispenser, and a pulse generator, wherein said pulse generator: is situated in either one of said supply distributor and said dispenser; is passed through by at least a portion of said liquid; and comprises at least a first surface and a second surface, which face each other and perform a relative movement and comprise respective passages for the liquid; and wherein said first surface and second surface, which are passed through by the liquid, generate in the liquid periodic pulses of pressure having a predetermined frequency dependent on the relative speed of said two surfaces.

Abstract: Shell and tube heat exchanger (1) comprising a first outer shell (2) and a tube bundle (3), inlet and outlet interfaces communicating with the shell side and with the tube side for a first fluid and for a second fluid respectively, wherein the exchanger comprises a second shell (4) which is inside said first shell (2) and surrounds said tube bundle (3); said second shell (4) comprises at least one releasable longitudinal joint (32) and a plurality of longitudinal sections connected by releasable joints; said second shell (4) delimits the shell side of the exchanger (1) around said tube bundle (3), and further defines a flushing interspace (5) communicating with said shell side, said first fluid flows through said shell side along one or more longitudinal passages, and said first fluid and said second fluid are counter-current along said one or more longitudinal passages.