Lear Siegler Measurement Controls Corporation

Lear Siegler, Inc.

Ronald L Ketchum

Gerald F McGowan

Allan L Budd

Gerald W Price

Carl E Polhemus

A photometric analyzer for measuring differential total reduced sulfur in a sample gas stream is provided. It includes a supply for a sulfur bearing gas sample, an oven having an inlet connected to the supply for converting TRS to SO.sub.2 and an outlet through which the gas sample is discharged. A valve is connected to the outlet of the oven. An SO.sub.2 bypass line is connected between the supply and the valve. A sample cell with transparent ends has an inlet adjacent one end connected to the valve for alternately receiving sample gas from either the oven or the bypass line and has an outlet adjacent the other end. A pump connected to the sample cell outlet draws the gas sample through the sample cell. A light source at the one end of the sample cell directs light of a predetermined wave length through the sample cell. A light sensing device at the other end detects the amount of light passing through the sample cell at any given time and provides an output signal to an analyzer. The analyzer determines the TRS in the gas sample. Zero air is supplied to the valve so that the zero air can be cycled into the sample cell for measurement by the analyzer to determine SO.sub.2 levels in the sample gas. A heat exchanger assures that each of the gases and air are at a constant temperature. The pressure of the gases and air is held at a constant pressure as they pass through the sample cell by a pressure regulator.

Photometric analyzer for differential total reduced sulfur measurement

The present invention relates to an apparatus which can be inserted between the stack and a transceiver of a transmissometer to provide zero and span measurements using the primary light source from the transceiver. The apparatus includes a calibration device mounted between the transceiver and one side of the stack and within the path of the light beam. A zero reflector is mounted within the calibration device for movement back and forth between an inactive position and an active position within the path of the light beam to reflect the same amount of light back into the transceiver as the retro-reflector would across the stack when the stack is clear of smoke. In addition, means is connected to the zero reflector for accomplishing this movement. A span filter is also provided within the calibration device which is movable between an active position in the light beam path to provide an upscale reference calibration check. The invention further contemplates a method of using the apparatus to establish zero and upscale references during initial set-up, followed by periodic establishment of new values indicative of soiling of the transceiver windows.

Apparatus for full-system zero check and window soiling measurement and

A dilution extractive probe assembly for sampling a gas stream in a stack is provided. It includes a hollow tubular dilution probe having a first end for receiving a sample of the gas stream from the stack to be analyzed and a second end through which the sample is discharged after dilution. A first filter is provided at the first end of the probe for filtering the sample gas it passes into the probe. A critical orifice is located within the probe downstream of the first filter. A first heater is provided for heating the first filter to maintain the sample at a temperature above the dew point of the sample gas. A partial vacuum is created for drawing the sample through the filter and into the probe. An eductor is located adjacent the second end of the probe for mixing the sample with a dilution gas. A second heater for heating the eductor to maintain the sample gas at a temperature above its dew point as it passes through the eductor is provided.

Dilution extractive probe

Apparatus is disclosed to accurately measure and analyze multiple component interfering gases which coexist in the stack gas effluent generated from a combustion process which utilizes a non-dispersive, narrowband infrared absorption technique. The apparatus includes a probe in the stack with an optical measurement cavity (34) through which the stack gases are passed. A transceiver (14) mounted to the probe includes an optical portion operatively associated with the measurement cavity including a chopped light source (54), (60), (62) for projecting beams of light into the measurement cavity and a detector (86) for detecting the attenuation of the gases to provide a measure of the extent of absorption of each gas of interest. A control unit, preferably remote from the transceiver, preferably a programmed digital computer, and preferably via a J-box (18) converts the electric outputs to a corresponding % modulation and in turn corrects for temperature, pressure and interference between gases. The results may be displayed on a front panel (174) or used, for example, to maximize efficiency in a combustion process.

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Littleton, CO, United States of America

Ronald L Ketchum