Methane analyzer
AssigneeBeckman Instruments, Inc.
InventorsRadhakrishna Murty Neti, Ray Lawrence Roggenkamp
Life of this patent
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Abstract
A reactor for removing contaminants such as reactive hydrocarbons from the gas being sampled by gas component determination apparatus is disclosed. A confined path is disposed adjacent a high purity quartz lamp capable of generating low order wavelengths. By selecting the flow rate of the sample gas past the quartz lamp in the presence of ozone, all hydrocarbons can be photo-oxidized or all hydrocarbons with the exception of methane. Apparatus is also disclosed employing the reactor wherein the methane content of a sample gas can be determined. The sample gas is alternately measured as to the quantity of all hydrocarbons contained therein and then measured for methane. The difference between the two readings is indicative of the amount of non-methane hydrocarbons present.
Claims14
The method of measuring the quantity of methane in a gas sample comprising the steps of:
- a. passing the gas sample through an enclosed space having a source therein emitting light energy including wavelengths approaching but not less than 147 nm at a flow rate sufficiently slow to cause any hydrocarbon molecules in the gas sample to attain a superactive state;
- b. exposing the gas sample containing said superactive hydrocarbon molecules to ozone in excess for a time sufficient to photo-oxidize all non-methane hydrocarbons and photo-oxidize any methane in a known proportional amount;
- c. measuring the quantity of hydrocarbons in the photo-oxidized gas sample whereby the quantity of methane in the photo-oxidized gas sample is determined;
- and,
- d. rescaling the quantity measured in step (c) as a function of the proportional photo-oxidation of methane effected in step (b) whereby the quantity of methane in the original un-photo-oxidized gas sample is determined.
The method of removing the effects of hydrocarbons in a gas sample to be analyzed for components comprising the steps of:
- a. passing the gas sample through an enclosed space having a source therein emitting light energy of wavelengths approaching but not less than 147 nm at a flow rate sufficiently slow to cause any hydrocarbon molecules in the gas sample to attain a superactive state;
- and,
- b. exposing the gas sample containing said superactive hydrocarbon molecules to ozone in excess for a time sufficient to photo-oxidize said superactive hydrocarbon molecules.
Apparatus for detecting the quantity of a specific component in a gas sample and including contaminant rejection means comprising:
- a. a reactor capable of photo-oxidizing any contaminants in the gas sample and having an input thereto and an output therefrom;
- b. valve means having a first input, a second input and an output wherein in one position said first input is connected to said output and in a second position said second input is connected to said output;
- c. gas sampling means;
- d. first connection means interconnecting said gas sampling means to said input of said reactor and to said first input of said valve means;
- e. second connection means interconnecting said output of said reactor to said second input of said valve means;
- f. means for detecting, measuring and displaying the quantity of the specific component having input means for a sample thereto;
- and,
- g. third connection means interconnecting said output of said valve means to said input means of said detecting, measuring and display means whereby when said valve means is in said first position the gas sample will bypass said reactor and when said valve means is in said second position the gas sample will pass through the reactor.
Dependencies are inferred from the claim text.