Abstract:
Apparatus for converting Spent Pot Lining (SPL) into inert slag, aluminum fluoride and energy includes a plasma arc furnace such that the destruction of SPL occurs therein. The furnace generates an electric arc within the waste, which arc travels from an anode to a cathode and destroys the waste due to the arc's extreme temperature, thereby converting a mineral fraction of SPL into vitrified inert slag lying within a crucible of the furnace. The furnace gasifies the carbon content of the SPL and produces a well-balanced syngas. The gasification takes place due to the controlled intake of air and steam into the furnace. The gasification reaction liberates a significant amount of energy. Steam captures this excess energy, to provide part of the oxygen requirement for gasification and to contribute to raise the syngas H2 content. Steam also contributes to converting some SPL fluorides (NaF and Al2F3) into hydrogen fluoride. The plasma SPL processing system is compact (occupying less area than some competitive methods of SPL treatment), can be installed in close proximity to the aluminium plant (minimizing transportation of SPL and AlF3), and requires only electricity as its energy source and thus no fossil fuels.
Abstract:
An apparatus for producing metallic powders from molten feedstock includes a heating source for melting a solid feedstock into a molten feed, and a crucible for containing the molten feed. A liquid feed tube is also provided to feed the molten feed as a molten stream. A plasma source delivers a plasma stream, with the plasma stream being adapted to be accelerated to a supersonic velocity and being adapted : to then impact the molten stream for producing metallic powders. The feed tube extends from the crucible to a location where a supersonic plasma plume atomizes the molten stream. The plasma source includes at least two plasma torches provided with at least one supersonic nozzle aimed towards the molten stream. The multiple plasma torches are disposed symmetrically about the location where the supersonic plasma plumes atomize the molten stream, such as in a ring-shaped configuration.
Abstract:
A system for generating high pressure steam from dirty water uses a combination of submerged plasma arcs and electrical resistive heating. Dirty water from steam assisted gravity drainage, or other dirty water producing process, which needs to be converted into high pressure steam, is fed directly without any pre-treatment, into a plasma fired steam generator, powered by submerged electrodes. The combination of electric arc plasma and resistive heating is created between the submerged electrodes. The heat so generated will boil the water portion of the dirty water feed to generate steam that is collected in a steam space and then removed therefrom. The solids and other residues (residual sludge) present in the feed water settle down at the bottom of the steam generator and are removed via a blow-down stream. The plasma arcs are used to intermittently remove any scaling or solid deposits that can accumulate on the electrodes.
Abstract:
A method for producing hydrogen and carbon powder from the plasma pyrolysis of hydrocarbons is disclosed and includes a DC n on-transferred electric arc plasma torch, a hot-wall reactor, for example lined with refractory or a graphite (slippery material), and a cyclone. The cyclone is adapted to recover heavier carbon particles and allow part of the hydrogen, unconverted hydrocarbon and lighter carbon particles to be recycled to the reactor to improve the overall yield of hydrogen. The prolonged contact with the plasma plume provides a typically complete conversion to hydrogen and carbon powder due to the hot walls of the reactor. The carbon powder leaving the plasma plume solidifies into a graphite- like powder in the reactor. A turbulence inside the reactor is adapted to prevent the buildup of soot on a reactor surface via the recycling of hydrogen, hydrocarbon gas or carbon powder or a mix of thereof to the reactor.
Abstract:
A process and an apparatus using pure silicon as raw material with no other pre- processed material for producing nano-Silicon and/or nano-Silicon-carbon coated composite material in the form of particles, nanowires or a combination of both, for use in a high capacity and high energy efficiency manufacturing of anodes for Lithium-ion batteries. The apparatus comprises a reactor including at least one electrode and adapted to provide at least one arc, e.g. a DC transferred arc, for melting and vaporizing silicon provided in the reactor. A quenching system is provided for delivering a gas for quenching, in the reactor, the so-produced silicon vapour so as to form nano particles and/or nano wires. The reactor is under vacuum. The gas can be injected by a vortex and/or via the electrode that is hollow. The electrode is consumable and vertically movable to control an arc voltage and to compensate for electrode erosion.
Abstract:
An apparatus and a process for the production of high purity silicon from silica containing material such as quartz or quartzite, using a vacuum electric arc furnace, are disclosed.
Abstract:
An apparatus is disclosed wherein an electric arc is employed to heat an injected gas to a very high temperature. The apparatus comprises four internal components: a button cathode and three cylindrical co-axial components, a first short pilot insert, a second long insert and an anode. Vortex generators are located between these components for generating a vortex flow in the gas injected in the apparatus and which is to be heated at very high temperature by the electric arc struck between the anode and cathode. Cooling is provided to prevent melting of three of the internal components, i.e. the cathode, the anode and the pilot insert. However, to limit the heat loss to the cooling fluid, the long insert is made of an insulating material. In this way, more electrical energy is transferred to the gas.
Abstract:
In a fossil fuel waste incineration or plasma gasification process, waste heat generated by combustion of waste is captured by a heat transfer fluid and conveyed to an Organic Rankine Cycle (ORC) for energy recovery. In the case of a fossil fuel-fired waste incineration system, the heat transfer fluid captures waste heat from a double-walled combustion chamber, a heat exchanger being used to cool the hot process exhaust (gas cooler). In the case of a plasma waste gasification system, the heat transfer fluid captures waste heat from a plasma torch, a gasification chamber and combustion chamber cooling jackets as well as any other high-temperature components requiring cooling, and then a heat exchanger used to cool the hot process exhaust (gas cooler). The heat exchanger may take on several configurations, including plate or shell and tube configurations.
Abstract:
A consumable electrode vacuum arc furnace and, more particularly, a direct current consumable electrode vacuum arc furnace is provided, wherein no water cooling is needed to cool down typically neither the electrodes, nor any other parts of the furnace, and this includes the shell, the flanges ports and the electrical connections of the furnace. The present furnace uses non-metallic electrodes, such as graphite electrode, which are suitable for melting metals, smelting of metal ores, and metal oxide to elemental metal where the use of graphite electrodes is a common practice. The present furnace and electrode assemblies render possible to perform a true continuous process of melting and smelting under controlled pressure.
Abstract:
The present application relates to a plasma atomization process and apparatus for producing metallic powders from at least one wire/rod feedstock. In the process, an electrical arc is applied between the at least one wire/rod feedstock, and a plasma torch is employed to generate a supersonic plasma stream at an apex at which the electric arc is transferred to the at least one wire/rod to melt and atomize the at least one wire/rod feedstock to produce the metallic powders. An anti-satellite diffuser is employed to prevent recirculation of the powders in order to avoid satellite formation.