Buffer gas

About: Buffer gas is a research topic. Over the lifetime, 3565 publications have been published within this topic receiving 47283 citations.

Burner assembly with fuel pre-mix and combustion temperature controls

Abstract: A burner assembly has a combustion chamber in which combustion takes place in an elongate centrally disposed combustion tube. An outer housing encases the combustion tube and provides an annular space between an inner wall of the housing and the combustion tube. Part of the exhaust gases exiting from the combustion tube are diverted from the downstream end thereof to be returned through the annular space to the upstream end of the combustion tube. Fuel is injected into the diverted exhaust gases, volatilized when in liquid form and mixed with the diverted gases. The fuel and gas mixture is further combined with a buffer gas and becomes entrained into and mixed with a high velocity of combustion air which is injected into the upstream end of the combustion tube. The flame temperature may be monitored and the quantity of the buffer gas added may be controllably varied based on temperature readings from the monitoring process to minimize the generation of nitrous oxides.

Effect of buffer gas ratios on the relationship between cell temperature and frequency shifts of the coherent population trapping resonance

Abstract: We studied the relationship between pressure ratio of the buffer gases (argon and neon) and the rate of coherent population trapping resonance frequency shift with cell temperature in Rb85. We found that when the total pressure of the buffer gases varies within the range of 5–15kPa, the frequency shift rate varies along a bell shaped curve. Every curve crossed the horizontal axis at two points that are roughly symmetrical with respect to the midpoint at 1:1. This allows us to minimize the rate of frequency shift by adjusting the pressure ratio of the buffer gases to these two points.

Negative ions generated by reactions with oxygen in the chemical ionization source. I. Characterization of gas‐phase and wall‐catalyzed reactions of fluorene, anthracene and fluoranthene

Abstract: The methane negative ion chemical ionization (NICI) mass spectra of polycyclic aromatic hydrocarbons are usually dominated by molecular, M− ˙ or M H− ions; however, ions resulting from additions to M have also been reported. Some of these ions have been observed at [M + 14]− ˙, [M + 15]−, [M + 30]− and [M + 32]−˙ and have been attributed to reactions with either oxygen-containing impurities in the buffer gas or alkyl radical species generated by ionization of a hydrocarbon buffer gas. In this study, the NICI spectra of fluorene, anthracene and fluoranthene were studied in detail using quadrupole and Fourier transform mass spectrometers. Spectra were acquired when reactive species such as oxygen, water, nitrous oxide and carbon dioxide were added to the nitrogen buffer gas. Experiments with deuterated methane were also carried out. These studies indicated that buffer gas impurities affect the NICI spectra; however, gas-phase ion-molecule reactions were not responsible for all of the observed products. In addition to electron- and ion-molecule reactions, ions were observed that resulted from wall-catalyzed oxidation reactions followed by electron capture. These reactions were enhanced by the addition of oxygen and elevated ion source temperatures. Depending upon the parent PAH structure, oxidation products such as ketones, quinones and anhydrides were formed.

Trace constituent detection in inert gases

Abstract: A method and apparatus for the detection of trace constituents in inert gases. Three modes of operation of the said invention are most preferred. In the first embodiment, a dielectric barrier discharge cell receives an inert gas, excites the gas, and the gas is then allowed to mix with additional gas in which the constituent to be measured is entrained. Energy is then passed from the excited states of the inert gas to the analytes of interest creating charged analytes of interest which are then measured through the use of commercial electrometers. In a second embodiment, the dielectric barrier discharge device receives the analyte entrained within the inert gas and the gas and, in some cases, the analytes are excited. The excited species then pass on and any resulting ionized species are then detected through the use of an electrometer. In the third embodiment, the analyte is entrained within the inert gas in the presence of a second gaseous constituent, reacts with the gaseous constituent, and then passes on to a thermionic emitting source. The altered constituent is then selectively ionized by the thermionic source and this ion is measured by an electrometer.

Ionic recombination of Kr+ and Kr+2 with F− in dense buffer rare gases

Abstract: Rates, α, for the recombination of Kr+ and Kr+2 with F− in various buffer rare gases (He, Ne, Ar, Kr, Xe) at 300 K are calculated for a wide range of gas pressures For pressures 1–5 atm, the population of KrF* via recombination is greatest for Ne and Ar as third bodies, yielding α∼3×10−6 cm3 sec−1, while for pressures ≳10 atm, He is to be preferred as a buffer gas