Virtual impactor for removing particles from an airstream and method for using same

Claim 1

An apparatus for separating substantially all of the particles from an airstream containing particles comprising: (a) nozzle means for accelerating an entering airstream, said nozzle means comprising an inlet and an outlet elongated in the length dimension having a width dimension of between about 0.007 and 0.015 inches, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) particle receiving means comprising an inlet elongated in the length dimension having a width dimension of between about 0.013 and 0.021 inches and an outlet, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, said receiving means being positioned downstream from said outlet of said nozzle means so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle means and said longitudinal axis of said receiving means are substantially coaxial and so that the width dimension of said nozzle means outlet and the width dimension of said receiving means inlet are substantially parallel; (c) a chamber in fluid communication with said lateral flow gap including an outlet; (d) first vacuum means fluidly connected with said receiving means outlet for drawing a minor portion of the airstream therethrough; and (e) second vacuum means fluidly connected with said chamber outlet for drawing a major portion of the airstream therethrough.

Claim 2

An apparatus for separating substantially all of the particles from an airstream containing particles comprising: (a) nozzle means for accelerating an entering airstream, said nozzle means comprising an inlet and an outlet elongated in the length dimension having a width dimension of between about 0.007 and 0.015 inches, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) particle receiving means comprising an inlet elongated in the length dimension having a width dimension of between about 0.013 and 0.021 inches and an outlet, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, said receiving means being positioned downstream from said outlet of said nozzle means so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle means and said longitudinal axis of said receiving means are substantially coaxial and so that the width dimension of said nozzle means outlet and the width dimension of said receiving means inlet are substantially parallel; (c) a chamber in fluid communication with said lateral flow gap including an outlet; (d) first vacuum means fluidly connected with said receiving means outlet for drawing a minor portion of the airstream therethrough; and (e) second vacuum means fluidly connected with said chamber outlet for drawing a major portion of the airstream therethrough.

Claim 9

An apparatus for separating and collecting the components of an airstream, said apparatus comprising: (a) nozzle means for accelerating an entering airstream, said nozzle means comprising an inlet and an outlet elongated in the length dimension having a width dimension of between about 0.007 and 0.015 inches, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) particle receiving means comprising an inlet elongated in the length dimension having a width dimension of between about 0.013 and 0.021 inches and an outlet, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, said receiving means being positioned downstream from said outlet of said nozzle means so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle means and said longitudinal axis of said receiving means are substantially coaxial and so that the width dimension of said nozzle means outlet and the width dimension of said receiving means inlet are substantially parallel; (c) chamber means in fluid communication with said lateral flow gap including an outlet; (d) particle collection means attached downstream of said outlet of said receiving means; (e) first vacuum means fluidly connected with said receiving means outlet for drawing a portion of the airstream therethrough; (f) gas collection means attached downstream of said outlet of said chamber means; and (g) second vacuum means fluidly connected with said chamber outlet for drawing a major portion of the airstream therethrough.

Claim 10

An apparatus for separating and collecting the components of an airstream, said apparatus comprising: (a) nozzle means for accelerating an entering airstream, said nozzle means comprising an inlet and an outlet elongated in the length dimension having a width dimension of between about 0.007 and 0.015 inches, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) particle receiving means comprising an inlet elongated in the length dimension having a width dimension of between about 0.013 and 0.021 inches and an outlet, and further having a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, said receiving means being positioned downstream from said outlet of said nozzle means so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle means and said longitudinal axis of said receiving means are substantially coaxial and so that the width dimension of said nozzle means outlet and the width dimension of said receiving means inlet are substantially parallel; (c) chamber means in fluid communication with said lateral flow gap including an outlet; (d) particle collection means attached downstream of said outlet of said receiving means; (e) first vacuum means fluidly connected with said receiving means outlet for drawing a portion of the airstream therethrough; (f) gas collection means attached downstream of said outlet of said chamber means; and (g) second vacuum means fluidly connected with said chamber outlet for drawing a major portion of the airstream therethrough.

Claim 22

A method for removing the particulate components of an airstream comprising; (a) passing an airstream through a nozzle having an elongated outlet, said nozzle outlet being elongated in the length dimension and having a width dimension of between about 0.007 and 0.015 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) drawing a first portion of the airstream into a particle receiving chamber having an elongated inlet and an outlet, the inlet being elongated in the length dimension and having a width dimension of between about 0.013 and 0.021 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, the receiving chamber being positioned downstream from said outlet of said nozzle so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle and said longitudinal axis of said receiving chamber are substantially coaxial and so that the width dimension of said nozzle outlet and the width dimension of said receiving chamber inlet are substantially parallel, so that substantially all of the particles of the airstream are drawn into the receiving chamber with the first portion of the airstream; and (c) drawing a second portion of the airstream through the gap between the nozzle outlet and the receiving chamber inlet, wherein the second portion of the airstream is substantially free of particles.

Claim 23

A method for removing the particulate components of an airstream comprising; (a) passing an airstream through a nozzle having an elongated outlet, said nozzle outlet being elongated in the length dimension and having a width dimension of between about 0.007 and 0.015 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) drawing a first portion of the airstream into a particle receiving chamber having an elongated inlet and an outlet, the inlet being elongated in the length dimension and having a width dimension of between about 0.013 and 0.021 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, the receiving chamber being positioned downstream from said outlet of said nozzle so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle and said longitudinal axis of said receiving chamber are substantially coaxial and so that the width dimension of said nozzle outlet and the width dimension of said receiving chamber inlet are substantially parallel, so that substantially all of the particles of the airstream are drawn into the receiving chamber with the first portion of the airstream; and (c) drawing a second portion of the airstream through the gap between the nozzle outlet and the receiving chamber inlet, wherein the second portion of the airstream is substantially free of particles.

Claim 29

A method of concentrating particles in an airstream containing particulate and gaseous components comprising; (a) passing the airstream through a nozzle having an outlet, said nozzle outlet being elongated in the length dimension and having a width dimension of between about 0.007 and 0.015 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) drawing a minor portion of the airstream into a particle receiving chamber having an elongated inlet and an outlet, the inlet being elongated in the length dimension having a width dimension of between about 0.013 and 0.021 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, the receiving chamber being positioned downstream from said outlet of said nozzle so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle and said longitudinal axis of said receiving chamber are substantially coaxial and so that the width dimension of said nozzle outlet and the width dimension of said receiving chamber inlet are substantially parallel, so that substantially all of the particles of the airstream are drawn into the receiving chamber with the minor portion of the airstream; and (c) drawing the major portion of the airstream through the gap between the nozzle outlet and the receiving chamber inlet, wherein the major portion of the airstream is substantially free of particles.

Claim 30

A method of concentrating particles in an airstream containing particulate and gaseous components comprising; (a) passing the airstream through a nozzle having an outlet, said nozzle outlet being elongated in the length dimension and having a width dimension of between about 0.007 and 0.015 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated outlet; (b) drawing a minor portion of the airstream into a particle receiving chamber having an elongated inlet and an outlet, the inlet being elongated in the length dimension having a width dimension of between about 0.013 and 0.021 inches and a longitudinal axis parallel to the airstream flow direction and normal to the width and length dimensions and passing through the center of said elongated inlet, the receiving chamber being positioned downstream from said outlet of said nozzle so that a lateral flow gap of between about 0.008 and 0.015 inches is formed between said nozzle means outlet and said receiving means inlet, and further being positioned so that said longitudinal axis of said nozzle and said longitudinal axis of said receiving chamber are substantially coaxial and so that the width dimension of said nozzle outlet and the width dimension of said receiving chamber inlet are substantially parallel, so that substantially all of the particles of the airstream are drawn into the receiving chamber with the minor portion of the airstream; and (c) drawing the major portion of the airstream through the gap between the nozzle outlet and the receiving chamber inlet, wherein the major portion of the airstream is substantially free of particles.