Thermo Fisher Scientific Gmbh

Other

The Coca-cola Company

Thermedics Detection, Inc.

Dirk Appel

Jeffrey S Socha

Dieter Kita

James H Grassi

David H Fine

David P Rounbehler

Eugene K Achter

Stephen J MacDonald

Freeman W Fraim

Jonathan E Bosworth

Daniel A Dussault

Robert F Mouradian

Gaston E Marzoratti

Shrikrishna H Nabar

Thomas M Levine

Jeffrey Socha

An oxidized mercury converter utilizes a combination of heat, reduced pressure, and dilution when converting oxidized mercury in a gas sample into elemental mercury. The converter applies heat to a gas sample to thermally convert oxidized mercury within a gas sample into elemental mercury and an oxidizing component, and thereafter reduces the pressure of the gas sample to minimize combination of the elemental mercury with other oxidizing compounds present in the gas sample and/or with byproducts of the thermal conversion (e.g., the oxidizing components). The converter thus allows an accurate analysis of the total amount of mercury, both oxidized and elemental forms, present within a gas sample without the need to use consumable reagents in the mercury conversion process.

Method and apparatus for converting oxidized mercury into elemental mercury

A gas analyzer system includes an optical source, an optical filter assembly, a controller, and an analyzer. The optical source generates an optical signal. The optical filter assembly includes different optical filters in which to filter the optical signal. During operation, the controller selects sequential application of each of the different optical filters in a path of the optical signal to modulate the optical signal using different frequency bands of optical energy. The modulated optical signal passes through an unknown sample. Based on absorption of the optical signal by the sample gas at different frequencies, the optical analyzer detects which types of multiple different gases are present in the sample.

Gas analyzer system

Disclosed are a system and method for monitoring total mercury within a gas sample in a substantially continuous manner and for calibrating for both elemental and oxidized mercury. A converter of the Continuous Emission Monitoring System (CEMS) receives a gas sample containing vaporized mercury from a probe. The converter converts oxidized mercury present within the gas sample into an elemental mercury component and an oxidizing component using thermal cracking. The converter also reduces the pressure of the gas sample to minimize recombination of the elemental mercury component with the oxidizing components. A mercury analyzer of the system receives the reduced pressure gas sample from the converter and detects the fluorescence of the elemental mercury within the sample. The mercury analyzer holds the gas sample at the reduced pressure to reduce an effect of fluorescence quenching on the fluorescence of the elemental mercury within the sample and provides substantially accurate measurement of the concentration of the elemental mercury in the gas sample.

Method and apparatus for monitoring mercury in a gas sample

An improved elemental mercury analyzer utilizes a fluorescence assembly in combination with a fluorescence quenching reduction mechanism to detect the concentration of elemental mercury within an emission gas sample, via fluorescence of the mercury within the gas sample, while minimizing fluorescence quenching of the gas sample. In one arrangement, the analyzer contains the emission gas sample under a vacuum or negative pressure while detecting fluorescence of the elemental mercury within the emission gas sample. By performing fluorescence detection of the emission gas sample at reduced pressure relative to the pressure of the as-sampled emission gas, the analyzer reduces the number of particle collisions within the emission gas sample over a certain period of time. Such collisional deactivation, and/or the addition of oxygen depleted gas such as nitrogen to the gas sample, reduces fluorescence quenching of the emission gas sample, improving accuracy of detection of mercury.

Method and apparatus for detecting the presence of elemental mercury in a gas sample

Disclosed is a method and apparatus for sampling and determining the presence of certain substances, such as residues of contaminants in containers. The method includes steps of: injecting compressed air into said containers in order to displace at least a portion of the contents thereof; evacuating a sample of the container contents so displaced by applying suction thereto; and analyzing the sample evacuated to determine the presence or absence of the certain residues therein. The compressed air is injected through a nozzle into an opening in the containers to displace a portion of the container contents and form a sample cloud outside of the container. The sample cloud is then at least partially evacuated by suction and the sample is analyzed for the presence of contaminants such as nitrogen containing compounds or hydrocarbons. The sample cloud may be split into first and second portions. Contaminants in the first portion are detected by a chemiluminescence detector and the second portion by a pulsed fluorescence detector.

Method and system for sampling and determining the presence of compounds

A detection system for detecting the emission (i.e., the fluorescence or phosphorescence) from a contaminant contained in a sample gas. In order to keep the optics of the system clean and maintain a high signal-to-noise ratio in the detected signal, the detection system contains a housing separated into illumination and sample chambers by an aperture-containing partition. A sample inlet port is connected to the sample chamber, and a purge inlet port is connected to the illumination chamber to direct the purge and sample gasses into their respective chambers. A vacuum system is connected to a vacuum port on the sample chamber to simultaneously draw the sample and purge gasses into their chambers through the inlet ports; the purge gas is then drawn through the aperture and into the sample chamber. Finally, both gasses are drawn out of the sample chamber through the vacuum port. Thus, the vacuum provides a flow of sample gas into the sample chamber, and a flow of purge gas into the illumination chamber to reduce contact between the sample gas and a portion of the optics, thereby keeping them free of debris.

Emission detection systems for determining the presence of contaminants

Growing community of inventors

Salem, MA, United States of America

Dirk Appel