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Title: 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 » effectively traps the sub-micron sized particles for later analysis.« less

Inventors:
 [1];  [2]
  1. (Aiken, SC)
  2. (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) SRS
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 = {1985},
month = {1}
}

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