An installation is for the destruction of radioactive metallic sodium and includes a reaction vessel containing an aqueous solution, the reaction vessel having an aqueous solution outlet; a sodium feed circuit configured for feeding liquid metallic sodium into the reaction vessel; a liquid effluent treatment unit, comprising a drain tank and a drain line fluidically connecting the aqueous solution outlet to the drain tank; a gas treatment unit configured for diluting the gases and releasing the diluted gases into the atmosphere, the drain tank having a gas outlet fluidically connected to the gas treatment unit; an inert gas feed unit configured for feeding the drain tank.

A reactor has a reactor vessel and one or more reaction tubes. One or more power input elements are guided into the reactor vessel for the electrical heating of the reaction tube(s). The one or more power input elements each have a rod-shaped section, and the rod-shaped section(s) each run in a respective wall passage through a wall of the reactor vessel. A connection chamber into which the rod-shaped section(s) project is arranged outside the reactor vessel and adjacent to the wall of the reactor vessel through which the rod-shaped section(s) run in their wall passages. Gas feed means apply an inerting gas to the connection chamber, and the wall passages with the rod-shaped sections received therein in a longitudinally-movable manner are designed to be gas-permeable so that at least a portion of the inerting gas fed into the connection chamber flows out into the reactor vessel.

The disclosure pertains to a urea production plant and process using a high-pressure CO.sub.2 stripper, downstream medium-pressure treatment unit and a medium-pressure dissociator receiving urea synthesis solution from the reactor, wherein gas from the treatment unit and dissociator are condensed in a first condenser and off-gas from the synthesis section is condensed separately in a second condenser. A revamping method is also described.

Reactor for the high-pressure non-catalytic synthesis of melamine from urea, comprising coaxial inner reaction zone (6) and outer reaction zone (7) wherein a crude melamine is formed in the inner reaction zone and contacted with gaseous ammonia for stripping in the outer reaction zone, wherein a gaseous phase liberated in the outer zone is collected in a gas collection chamber (12) above the reaction zones, wherein the crude melamine melt is transferred from the inner zone into the outer zone via a submerged liquid passage below the liquid level to provide a liquid seal between the chambers.

A reactor for carrying out a chemical reaction has a reactor vessel, one or more reaction tubes and means for the electrical heating of the one or more reaction tubes. The reactor vessel has one or more discharge orifices which are permanently open or are set up to open above a preset pressure level, and gas feed means are provided, which are set up to feed an inerting gas into an interior of the reactor vessel.

This invention relates to a self cleaning reactor and to a process for the oligomerization of ethylene that employs a self-cleaning reactor. The reactor includes a mass of inert, particulate cleaning bodies that are entrained by the liquid in the reactor and scour the internal surfaces of the reactor during normal operation. This scouring action reduces the level of fouling on the reactor surfaces. Foulant material (polyethylene) is removed from the process on a continuous basis but the cleaning bodies remain within the reactor.

The invention relates to an improved system and method for relief of hot, high pressure, fouling fluid from the 1.sup.st Stage Reactor and the ISS in case of an unintended overpressure situation while allowing the quick establishing of normal fluid flow path once the overpressure situation has been corrected. This allows for rapid cooling of all subsequent reactor stages while minimizing VGO slop generation that needs reprocessing.

A cleaning system comprise: a first pipe 20 connected to a reactor 10 used for producing polysilicon by using chlorosilane as a raw material; a heat exchanger 30 connected to the first pipe 20; a second pipe 60 provided between the heat exchanger 30 and the first pipe 20; and a driving unit 50 provided at the first pipe 20 or the second pipe 60. A cleaning liquid circulates through the first pipe 20, the heat exchanger 30 and the second pipe 60 by the driving unit 50.

A high-pressure polymerization system having a) a polymerization reactor and b) a reactor blow down system having b1) a reactor blow down vessel, having a circular design over a major portion P having a L/D-ratio in the range from 1.75 to 10.0 and containing an aqueous quenching medium, b2) a release line connecting the polymerization reactor with the reactor blow down vessel and having an outlet located above a maximum level for the aqueous quenching medium, b3) a first emergency valve in the release line to open and close fluid communication between the polymerization reactor and the reactor blow down system, and wherein the release line outlet has a joining piece having an angle (a) between the central axis and a tangent at the reactor blow down vessel in the range from 5° to 70° and the reactor blow down vessel has a vent stack containing a constricted section.

Methods and systems for the controlled production of aqueous halogen solutions with varying compositions are disclosed. According to an embodiment, aqueous solutions of hypochlorite ions are modified through the sequential addition of pH adjusting chemicals, non-chloride halide ions, and halogen stabilizing compounds. Sensors, for measuring physical and chemical properties of the solutions as they change due to the impact of the various chemical reactions, are linked to a control system which, in turn, can control the input of one or more chemicals. The control system facilitates the production of a solution with desired characteristics in terms of pH, specific halogen composition, degree of halogen stabilization, and limiting the production of undesired by products such as bromate ions.