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US 5,679,957 AGranted
Method and apparatus for monitoring mercury emissions
AssigneeADA Technologies, Inc.
InventorsMichael D. Durham, Richard J. Schlager, Andrew D. Sappey, Francis J. Sagan, Roger W. Marmaro, Kevin G. Wilson
Life of this patent
Estimating the term…
Abstract
A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.
Claims47
A device for monitoring the presence of mercury in a gas stream, comprising:
- a gas handling system having a containment portion, an inlet portion, and an outlet portion for passage of a gas stream therethrough, said gas stream including speciated mercury and the interior of said inlet portion and containment portion being substantially resistant to the absorption of speciated and elemental mercury at or above the temperature of said gas stream;
- heating means for heating said inlet portion and containment portion to at least an operating temperature, said operating temperature being sufficient to convert said speciated mercury into elemental mercury;
- radiation means for transmitting radiation having a first wavelength through said gas stream in said containment portion, wherein a portion of said radiation is absorbed by said elemental mercury;
- a device for forming a magnetic field along the path of said radiation to produce a first portion of said radiation having said first wavelength and a second portion having a second wavelength;
- and
- radiation sensitive means for receiving said unabsorbed portion of said radiation and for providing a signal for use in detecting the presence of mercury in said gas stream.
3 more elements
A method for monitoring the presence of mercury in a gas stream containing speciated mercury, comprising:
- continuously introducing said gas stream into a gas handling system during a selected time interval;
- maintaining, during said time interval, an input portion and a containment portion of said gas handling system at an operating temperature sufficient to convert said speciated mercury to elemental mercury while said speciated mercury is in said gas stream;
- passing radiation through a magnetic field to form altered radiation;
- transmitting altered radiation through said containment portion during at least a portion of said time interval, wherein said elemental mercury absorbs a portion of said altered radiation;
- receiving said unabsorbed portion of said altered radiation with a radiation sensitive device;
- and
- using said received radiation to generate a signal for use in monitoring the presence of mercury in said gas stream.
4 more elements
A method for monitoring the presence of mercury in a gas stream containing speciated mercury and another radiation absorbing material, comprising:
- continuously introducing said gas stream into an inlet portion of a gas handling system during a selected time interval, said gas handling system being substantially free of a noble metal and a solid or liquid reducing agent;
- maintaining, during said time interval, said gas handling system at an operating temperature no less than about 900.degree. C. to convert said speciated mercury to elemental mercury in said inlet portion while said speciated mercury is in said gas stream;
- passing first radiation having a wavelength of 2537 angstroms through said heated gas stream, wherein said radiation absorbing material and said elemental mercury collectively absorb a first portion of said first radiation;
- passing second radiation having a wavelength different from 2537 Angstroms through said heated gas stream, wherein said radiation absorbing material absorbs a second portion of said second radiation;
- and
- comparing said first and second portions to determine a signal corresponding to the presence of mercury in said gas stream.
3 more elements
A device for monitoring the presence of mercury in a gas stream, comprising:
- a gas handling system having a containment portion, an inlet portion, and an outlet portion for passage of a gas stream therethrough, said gas stream including speciated mercury and the interior of said inlet portion and containment portion being substantially resistant to the absorption of speciated and elemental mercury at or above the temperature of said gas stream;
- heating means for heating said inlet portion and containment portion to at least an operating temperature, said operating temperature being sufficient to convert said speciated mercury into elemental mercury;
- radiation means for transmitting radiation through said gas stream in said containment portion, wherein a portion of said radiation is absorbed by said elemental mercury;
- and
- radiation sensitive means for receiving said unabsorbed portion of said radiation and for providing a signal for use in detecting the presence of mercury in said gas stream, wherein said inlet portion and containment portion are substantially free of a solid or liquid reducing agent.
2 more elements
A device for monitoring the presence of mercury in a gas stream, comprising:
- a gas handling system having a containment portion, an inlet portion, and an outlet portion for passage of a gas stream therethrough, said gas stream including speciated mercury and the interior of said inlet portion and containment portion being substantially resistant to the absorption of speciated and elemental mercury at or above the temperature of said gas stream;
- heating means for heating said inlet portion and containment portion to at least an operating temperature, said operating temperature being sufficient to convert said speciated mercury into elemental mercury;
- radiation means for transmitting radiation through said gas stream in said containment portion, wherein a portion of said radiation is absorbed by said elemental mercury;
- and
- radiation sensitive means for receiving said unabsorbed portion of said radiation and for providing a signal for use in detecting the presence of mercury in said gas stream, wherein said containment portion is contained within said input portion.
2 more elements
A device for monitoring the presence of mercury in a gas stream, comprising:
- a gas handling system having a containment portion, an inlet portion, and an outlet portion for passage of a gas stream therethrough, said gas stream including speciated mercury;
- heating means for heating said inlet portion and containment portion to at least an operating temperature, said operating temperature being sufficient to convert said speciated mercury into elemental mercury;
- radiation means for generating radiation of a plurality of wavelengths;
- means for polarizing the radiation to form polarized radiation, the polarizing means being located between said radiation means and said containment portion, wherein a portion of said polarized radiation is absorbed by said elemental mercury;
- and
- radiation sensitive means for receiving said unabsorbed portion of said radiation and for providing a signal for use in detecting the presence of mercury in said gas stream.
3 more elements
A device for monitoring the presence of mercury in a gas containing both speciated and elemental mercury, comprising:
- a first gas handling system having a first containment portion, a first inlet portion, and a first outlet portion for passage of a gas stream therethrough, the first gas stream being at least a portion of the gas;
- heating means for heating said first inlet portion and first containment portion to at least an operating temperature, said operating temperature being sufficient to convert said speciated mercury into elemental mercury;
- radiation means for transmitting radiation through said gas stream in said first containment portion, wherein a portion of said radiation is absorbed by said elemental mercury;
- first radiation-sensitive means for receiving said unabsorbed portion of said radiation and for providing a signal corresponding to the presence of speciated mercury in said gas, wherein said first inlet portion and said outlet portion each communicate with a conduit containing the gas containing both speciated and elemental mercury;
- a second gas handling system including a second containment portion, at a temperature less than said operating temperature, a second inlet portion and a second outlet portion in communication with said conduit for continuous passage of a second gas stream therethrough, said second gas stream being at least a portion of said gas;
- beam splitting means for directing a first radiation portion from said radiation means through said first containment portion and a second radiation portion through said second containment portion, wherein a portion of said second radiation portion is absorbed by elemental mercury in said second gas stream;
- and
- second radiation sensitive means for receiving an unabsorbed component of said second radiation portion and for providing a second signal corresponding to the presence of elemental mercury in said gas.
5 more elements
Dependencies are inferred from the claim text.