Method for sampling sub-micron particles
Abstract
Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar.RTM. and the assembly is then crushed into a pellet. Thismore »
- Inventors:
-
- Aiken, SC
- Ulmers, SC
- Issue Date:
- Research Org.:
- E I DUPONT DE NEMOURS & CO INC
- OSTI Identifier:
- 865523
- Patent Number(s):
- 4530250
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Classifications (CPCs):
-
B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01D - SEPARATION
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- DOE Contract Number:
- AC09-76SR00001
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- method; sampling; sub-micron; particles; apparatus; steps; collecting; sized; collection; chamber; cryogenic; cooling; accomplished; coil; tubing; carrying; nitrogen; liquid; form; changing; gas; phase; exiting; standard; filters; filter; diameter; equal; microns; trap; micron; blower; draws; air; diameters; cryogenically; cooled; moisture; condense; ice; heated; melts; drawn; passed; buchner; funnel; nuclepore; membrane; vacuum; trapping; therein; covered; top; bottom; surfaces; sheets; mylar; rtm; assembly; crushed; pellet; effectively; traps; analysis; cryogenic cooling; cryogenically cooled; bottom surfaces; sized particles; gas phase; bottom surface; collection chamber; sub-micron sized; liquid form; liquid nitrogen; method steps; particles therein; micron size; draws air; coil tubing; collecting sub-micron; effectively traps; tubing carrying; trap particles; micron sized; sub-micron particle; carrying nitrogen; /73/62/95/
Citation Formats
Gay, Don D, and McMillan, William G. Method for sampling sub-micron particles. United States: N. p., 1985.
Web.
Gay, Don D, & McMillan, William G. Method for sampling sub-micron particles. United States.
Gay, Don D, and McMillan, William G. Tue .
"Method for sampling sub-micron particles". United States. https://www.osti.gov/servlets/purl/865523.
@article{osti_865523,
title = {Method for sampling sub-micron particles},
author = {Gay, Don D and McMillan, William G},
abstractNote = {Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar.RTM. and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1985},
month = {Tue Jan 01 00:00:00 EST 1985}
}