摘要:
An arc furnace that utilizes a combined DC arc system and an AC joule heating system to melt the waste disposed therein and to keep the waste material in a molten condition. The DC arc system utilizes the AC joule heating electrodes as part of the DC current path, thereby eliminating the need for a counter DC electrode. Furthermore, the AC joule heating system provides for peripheral and radial AC current flow to neighboring AC joule heating electrodes, thereby creating a stirring effect in the molten waste. This design greatly simplifies the arc furnace control system while providing a more effective thermal control of the molten waste.
摘要:
An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil. During in-situ vitrification, the electrode assembly may also be operated in the non-transferred mode, while being withdrawn from holes in the earth, to produce vitrified columns of soil. The vitrified columns of soil can be coalesced with similar adjacent columns of soil in order to form a composite or unitary subterranean mass or barrier for contaminated material in a selected area. Multiple electrode assemblies can be employed to treat contamination located within a large area. An AC potential can be applied to adjacent electrode assemblies in order to promote coalescence of the adjacent columns of treated soil to form a composite or unitary mass.
摘要:
A thermal decomposition apparatus for wastes comprises: a heating chamber; an inlet port; at least one pair of electrodes provided within the heating chamber; a plurality of balls each taking the shape of a sphere whose primary ingredient is carbon, provided between the at least one pair of electrodes so as to produce an electric discharge when a voltage is applied across the at least one pair of electrodes; an outlet port for discharging the gases into which the wastes are thermally decomposed; oxygen free or vacuum environment forming means or evacuating means.According to the present invention, an inexpensive thermal decomposition apparatus for wastes is provided which thermally decomposes almost all wastes at a high temperature of not lower than about 3000° C. without producing harmful substances such as soot, dust, chlorine compounds; nitrogen compounds and/or dioxin.
摘要:
Methods and apparatus for treating waste are provided. Waste is converted in an arc plasma-joule heated melter system utilizing one or more arc plasma electrodes and a plurality of joule heating electrodes. The arc plasma electrode(s) can be configured for operation utilizing AC or DC power, or for switching between AC and DC power. The arc plasma electrodes can also be configured for independent arc voltage and arc current control. The joule heating circuits are configured for simultaneous operation with the arcing electrodes, but without detrimental interaction with the arcing electrodes. The systems provide stable, non-leachable products and a gaseous fuel. The gaseous fuel can be utilized in a combustion or non-combustion process to generate electricity.
摘要:
An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil. During in-situ vitrification, the electrode assembly may also be operated in the non-transferred mode, while being withdrawn from holes in the earth, to produce vitrified columns of soil. The vitrified columns of soil can be coalesced with similar adjacent columns of soil in order to form a composite or unitary subterranean mass or barrier for contaminated material in a selected area. Multiple electrode assemblies can be employed to treat contamination located within a large area. An AC potential can be applied to adjacent electrode assemblies in order to promote coalescence of the adjacent columns of treated soil to form a composite or unitary mass.
摘要:
An arc furnace that utilizes a combined DC arc system and an AC joule heating system to melt the waste disposed therein and to keep the waste material in a molten condition. The DC arc system utilizes the AC joule heating electrodes as part of the DC current path, thereby eliminating the need for a counter DC electrode. Furthermore, the AC joule heating system provides for peripheral and radial AC current flow to neighboring AC joule heating electrodes, thereby creating a stirring effect in the molten waste. This design greatly simplifies the arc furnace control system while providing a more effective thermal control of the molten waste.
摘要:
Methods and apparatus for high efficiency generation of electricity and low oxides of nitrogen (NO.sub.x) emissions are provided. The electricity is generated from combustion of hydrogen-rich gases produced in waste conversion units using ultra lean fuel to air ratios in the range of 0.4-0.7 relative to stoichiometric operation in internal combustion engine-generators or ultra lean operation in gas turbines to ensure minimal production of pollutants such as NO.sub.x. The ultra lean operation also increases the efficiency of the internal combustion engine. High compression ratios (r=12 to 15) can also be employed to further increase the efficiency of the internal combustion engine. Supplemental fuel, such as natural gas or diesel oil, may be added directly to the internal combustion engine-generator or gas turbine for combustion with the hydrogen-rich gases produced in waste conversion unit. In addition, supplemental fuel may be reformed into a hydrogen-rich gas in a plasma fuel converter and then introduced into the internal combustion engine-generator or a gas turbine for combustion along with supplemental fuel and the hydrogen-rich gases produced in waste conversion unit. The preferred embodiment of the waste conversion unit is a fully integrated tunable arc plasma-joule heated melter with a common molten pool and power supply circuits which can be operated simultaneously without detrimental interaction with one another. In this embodiment, the joule heated melter is capable of maintaining the material in a molten state with sufficient electrical conductivity to allow rapid restart of a transferred arc plasma.
摘要:
Methods and apparatus for treating waste are provided. Waste is converted in an arc plasma-joule heated melter system utilizing one or more arc plasma electrodes and a plurality of joule heating electrodes. The arc plasma electrode(s) can be configured for operation utilizing AC or DC power, or for switching between AC and DC power. The arc plasma electrodes can also be configured for independent arc voltage and arc current control. The joule heating circuits are configured for simultaneous operation with the arcing electrodes, but without detrimental interaction with the arcing electrodes. The systems provide stable, non-leachable products and a gaseous fuel. The gaseous fuel can be utilized in a combustion or non-combustion process to generate electricity.
摘要:
The present invention provides a relatively compact self-powered, tunable waste conversion system and apparatus which has the advantage of highly robust operation which provides complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The system provides the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or by an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In a preferred embodiment of the invention, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The apparatus may additionally be employed with reduced or without further use of the gases generated by the conversion process. The apparatus may be employed as a self-powered or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production.
摘要:
Methods and apparatus for high efficiency generation of electricity and low oxides of nitrogen (NO.sub.x) emissions are provided. The electricity is generated from combustion of hydrogen-rich gases produced in waste conversion units using ultra lean fuel to air ratios in the range of 0.4-0.7 relative to stoichiometric operation in internal combustion engine-generators or ultra lean operation in gas turbines to ensure minimal production of pollutants such as NO.sub.x. The ultra lean operation also increases the efficiency of the internal combustion engine. High compression ratios (r=12 to 15) can also be employed to further increase the efficiency of the internal combustion engine. Supplemental fuel, such as natural gas or diesel oil, may be added directly to the internal combustion engine-generator or gas turbine for combustion with the hydrogen-rich gases produced in waste conversion unit. In addition, supplemental fuel may be reformed into a hydrogen-rich gas in a plasma fuel converter and then introduced into the internal combustion engine-generator or a gas turbine for combustion along with supplemental fuel and the hydrogen-rich gases produced in waste conversion unit. The preferred embodiment of the waste conversion unit is a fully integrated tunable arc plasma-joule heated melter with a common molten pool and power supply circuits which can be operated simultaneously without detrimental interaction with one another. In this embodiment, the joule heated melter is capable of maintaining the material in a molten state with sufficient electrical conductivity to allow rapid restart of a transferred arc plasma.