CONTINUOUS ION MOBILITY MONITORING AS A LIQUID STREAM PROCESS SENSOR

IN A WIDE VARIETY OF INDUSTRIES, MANY INDUSTRIAL PROCESSES USE FLOWING STREAMS OF LIQUIDS AND GASES. BECAUSE THESE STREAMS ARE A COMPLEX MIXTURE OF CHEMICAL COMPOUNDS, KNOWLEDGE OF THE CONSTITUENTS IS ESSENTIAL FOR PROCESS CONTROL, QUALITY CONTROL, AND PROCESS IMPROVEMENT. MANY PREVALENT MONITORING TECHNIQUES REQUIRE THAT A SAMPLE BE EXTRACTED FROM THE STREAM AND ANALYZED EX SITU USING STANDARD CHEMICAL ANALYTICAL METHODS SUCH AS GAS CHROMATOGRAPHY, MASS SPECTROMETRY, ETC. THE EXISTING TECHNIQUES THAT ARE CAPABLE OF MONITORING THE PROCESS STREAM IN SITU ARE EITHER LIMITED TO SPECIFIC CONSTITUENTS OR HAVE POOR SENSITIVITY. CONSEQUENTLY, EXISTING CONTINUOUS-MONITORING TECHNIQUES HAVE LIMITED UTILITY (SUCH AS WARNING FOR ALARM CONDITIONS). A NOVEL LIQUID PROCESS STREAM SENSOR IS PLANNED THAT MAKES USE OF THE FACT THAT IONS OF A COMPOUND DRIFT WITH A UNIQUE MOBILITY IN AN APPLIED ELECTRIC FIELD. HENCE, A SPECTROMETER CAN BE BUILT THAT DETECTS THE VARIOUS CONSTITUENTS OF A LIQUID PROCESS STREAM USING THEIR ION MOBILITY SIGNATURE. THE IN-SITU CONTINUOUS MONITORING OF THE STREAM IS ACCOMPLISHED BY DIRECTING A SMALL PORTION OF A FLOWING PROCESS STREAM INTO THE ION MOBILITY SPECTROMETER USING A NOVEL SENSING HEAD. THIS SENSING HEAD, CALLED THE ELECTROSPRAY IONIZATION CHAMBER, NEEDS VERY SMALL SAMPLES (ON THE ORDER OF MICROLITERS PER MINUTE) FOR OPERATION. HENCE, THE PROCESS STREAM ITSELF IS UNDISTURBED BY THE MONITORING OPERATION. BECAUSE THE ION MOBILITY SPECTROMETER IS BASED ON A GENERAL SCIENTIFIC PRINCIPLE IT IS CAPABLE OF MONITORING A WIDE VARIETY OF PROCESS LIQUIDS.