New laser aerosol detector and monitor for use on high pressure gas streams. [For monitoring helium at 15 atmospheres in cryogenic refrigerator]

Conference · Sat Jan 01 00:00:00 EST 1977

OSTI ID:7300380

Harrison, Jr, W E; Shofner, F M; Miller, Jr, A C

A new laser particulate detection instrument is described which continuously measures the level of particulate matter and oil aerosols directly in a high pressure gas stream. It was developed to monitor, in situ, helium at 15 atmospheres (1.5 MPa) that is used in a cryogenic refrigerator. The recent introduction of oil-injected screw compressors in cryogenic systems for increased mechanical reliability has increased the possibility of helium contamination at the input to the refrigerator above the permissible level of a few parts per billion. The instrument uses forward scattering of laser light to detect particulate matter and accomplishes high sensitivity and stability by using unique automatic compensation of the entire electro-optical train. High sensitivity and stability permit the measurement of particles of between 0.3 and 3 ..mu..m diameter in quantities down to 24 micrograms per cubic meter, corresponding to 10 parts per billion. The instrument provides an analog voltage proportional to particulate mass concentration with a response time of about one second. The signal can be displayed on a chart reorder or a digital voltmeter or used for alarm purposes if preset concentration levels are exceeded. The direct measurement of particulate matter transported by the process flow is independent of gas pressure, velocity, temperature and composition.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: EY-76-C-02-77
• OSTI ID: 7300380
• Report Number(s): BNL-22929; CONF-770801-21
• Resource Relation: Conference: Cryogenic engineering conference, Boulder, CO, USA, 2 Aug 1977
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AEROSOLS
MONITORING
HELIUM
REFRIGERATING MACHINERY
CONTROL EQUIPMENT
FLUID FLOW
LASERS
LIGHT SCATTERING
MEDIUM PRESSURE
OILS
PARTICLES
WORKING FLUIDS
COLLOIDS
CRYOGENIC FLUIDS
DISPERSIONS
ELEMENTS
EQUIPMENT
FLUIDS
NONMETALS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
RARE GASES
SOLS
440300* - Miscellaneous Instruments- (-1989)
420201 - Engineering- Cryogenic Equipment & Devices