Flowrate and molecular weight determinations enable ultrasonic probe to pinpoint leaks

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Chem. Process. (Chicago); (United States)

OSTI ID:6823211

Potter, G F; Stadig, W P

The Exxon Chemical Americas (ECA) plastics plant in Mont Belvieu, TX produces approximately 600 million pounds per year of polyethylene, subsequently releasing hydrocarbons and inert gases into a flare system. When the plant was built in 1982, a system was installed to monitor the total flow of the process vent gases, emergency releases, and the inert gases used to purge lines or blanket vessels in order to help minimize the loss of valuable materials. To help locate sources of increased gas flow occurring in the flare line, spot samples were frequently taken and analyzed by gas chromatography. Not only were sample collection and analysis costly, but the elapsed time before the source of a leak was detected contributed to high gas losses. At times, spot flare samples alone were insufficient in determining the source of a leak. Since flow rates within the flare line varied and the rate could not always be measured reliably, excess steam was injected into the flare tip to maintain pollution control regulation compliance by assuring smokeless operation. The excess steam represented a potentially significant energy robber. To overcome the shortcomings of leak detection on the flare gas line, in July 1985, ECA replaced the original monitoring system with an ultrasonic flare gas flowmeter. Because both the velocity and composition of the flare gas can be very unsteady, the upstream-downstream interrogation direction of the ultrasonic signal is alternated about 100 times per second. Response time can be as short as 20 milliseconds; normally, however, differential readings are averaged over a few seconds to give an average flow.

• OSTI ID: 6823211
• Journal Information: Chem. Process. (Chicago); (United States), Journal Name: Chem. Process. (Chicago); (United States); ISSN CHPCA
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION CONTROL
CHEMICAL PLANTS
CONTROL
EFFICIENCY
ENERGY CONSERVATION
ENERGY EFFICIENCY
FLARING
FLOW RATE
FLOWMETERS
FLUIDS
GASES
INDUSTRIAL PLANTS
LEAK DETECTORS
MEASURING INSTRUMENTS
METERS
PERFORMANCE
PETROCHEMICAL PLANTS
POLLUTION CONTROL
SOUND WAVES
STEAM
ULTRASONIC WAVES