Abstract: Disclosed are a method and apparatus for high speed, selective detection of vapors of specific compounds, particularly nitrogen-containing compounds, utilizing a bypass branch and high speed gas chromatography for improved selectivity and sensitivity of detection. A system with two gas chromatographs (GC's) alternating in series with two pyrolyzers provides two time intervals of detection in a downstream detector, with the second time interval containing signals delayed and further separated relative to signals from the first time interval. The bypass branch, in diverting a portion of the flow of gas samples from passage through the second gas chromatograph and second pyrolyzer, avoids interferences in the first time interval of detection from non-GC-retained compounds decomposed in the second pyrolyzer. Also disclosed is an arrangement for rapid, precise heating of vapor concentrator tubes in which vapors are rapidly focussed and then injected into a GC, and for rapid, precise heating of the GC's.

Abstract: A method and apparatus for selective, high speed detection of vapors of specific gas-chromatographically-separable compounds. In the disclosed method separate analyses are performed on two portions of a gas sample formed by flash-heating trapped vapors to successively higher temperatures while flowing hydrogen carrier gas over coatings in/on which the vapors are held. Within a total time interval of about twenty seconds 1) two sample portions are formed, 2) each portion is rapidly separated in two series-connected, high speed, temperature-programmed gas chromatographs, and 3) specific compounds are identified by detection of NO gas formed during an oxidative pyrolysis of each separated portion. One application of the described method and apparatus is the rapid, selective, and sensitive detection of nitrogen-containing compounds such as the drugs methamphetamine, cocaine, and heroin.

Abstract: A closed stainless steel tube is used to provide pressure and media isolation between the core and coils of a sensor in the form of a variable core transformer. The core is connected to and moved with a slide valve of a screw compressor and its actuating piston. The current output from the secondary coil is converted into a voltage, linearized and communicated to a microprocessor for controlling the position of the slide valve and thereby the loading of the compressor.

Abstract: A method and system for recapturing and utilizing low grade energy in the form of low pressure vapors generated in an industrial evaporation process. A prime mover drives a screw compressor and concurrently provides heat at several levels which is utilized in a staged evaporation system in accordance with the requirements of the stages of the system. The screw compressor recompresses the contaminated vapors to a pressure and temperature sufficient to evaporate the major fraction of moisture to be removed in the industrial evaporation process.