Multi-station downflow centrifugal separation method and apparatus for separating particulate matter from gases

An improved, downflow, centrifugal separator apparatus, for separating particulate matter from particle-laden gas having a given velocity and pressure, said apparatus having a plurality of elongate, vertically-disposed separator units, each of said units having a vertically-disposed tube which defines a channel within which to conduct particle-laden gas;

• first means within said tube for causing particle-laden gas admitted into said tube to be (a) centrifugally swirled, and (b) directed into said channel;
• an elongate, vertically-disposed vessel enclosing said separator units, said vessel having an inlet opening, substantially at an uppermost end thereof, and above said separator units, for admitting particle-laden gas into said separator units and into said tubes thereof, and said vessel having an outlet opening, substantially at a lowermost end thereof, and below said separator units, for discharging therethrough particle-removed gas from said units;
• said units further having means for removing separated particles, together with a minor percentage of gas, from said tubes;
• a first station, within said vessel, comprising a first plurality of said separator units mounted therewithin in parallel relationship;
• a second station, within said vessel, comprising a second plurality of separator units mounted therewithin in parallel relationship;
• said second station being spaced apart from said first station, axially of said vessel;
• and means intermediate said stations for conducting particle-separated gas from said first station to said second station;
• wherein the improvement is comprised by:
• said separator units each having an additional tube positioned inside said vertically disposed tube so as to define an annular channel therebetween, and
• said first means comprises means for swirling gas with a given centrifugal action, and directing gas immediately thereafter into said annular channel to cause flow thereof in a generally axial direction;
• wherein
• said additional inner tube including slots therein for causing gas to turn inwardly, from said annular channel, into said tube;
• said additional tube having a hosepiece positioned and arranged for causing gas turned into said tube from said channel to be redirected in said same generally axial direction, and (b) obstructing flow of such turned gas in the opposite axial direction;
• and
• said first means of said first station comprises means for swirling gas with a centrifugal action which is less than the centrifugal action with which said first means of said second station can swirl gas.

A multi-station centrifugal separator apparatus, for separating particular matter from particle-laden gas, comprising:

• an elongated, separator vessel having an inlet near one end thereof for flowing particle-laden gas into the vessel and having an outlet near the other end thereof for flowing particle-removed gas out of the vessel,
• a plurality of stations in said vessel, each station containing a plurality of tubular centrifugal separator units,
• a first of said stations being positioned in said vessel near the inlet,
• a second of said stations being positioned in said vessel downstream from said first station,
• a third of said stations being positioned in said vessel downstream from said second station,
• said first station including first and second spaced-apart tube sheets,
• said first tube sheet extending generally across the interior of the vessel for defining an inlet chamber located between said first tube sheet and said inlet,
• said second tube sheet extending generally across the interior of said vessel spaced below said first tube sheet for defining a first particle discharge chamber located between said first and second tube sheets,
• said second station including third and fourth tube sheets,
• said third tube sheet extending generally across the interior of the vessel spaced below said second tube sheet for defining a first intermediate chamber located between said second and third sheets,
• said fourth tube sheet extending generally across the interior of the vessel spaced below said third tube sheet for defining a second particle discharge chamber located between said third and fourth tube sheets,
• said third station including fifth and sixth tube sheets,
• said fifth tube sheet extending generally across the interior of the vessel spaced below said fourth tube sheet for defining a second intermediate chamber located between said fourth and fifth tube sheets,
• said sixth tube sheet extending generally across the interior of the vessel spaced below said fifth tube sheet for defining a third particle discharge chamber located between said fifth and sixth tube sheets,
• a plurality of first tubular centrifugal separator units all of a same predetermined size in said first station having open, tubular, first upper ends in communication with said inlet chamber, and extending up through and being secured to said first tube sheet and having open, tubular second lower ends in communication with said first intermediate chamber, and extending down through and being secured to said second tube sheet,
• a second plurality of second tubular centrifugal separator units all of a same predetermined size in said second station having open, tubular, first upper ends in communication with said first intermediate chamber, and extending up through and being secured to said third tube sheet and having open, tubular, second lower ends in communication with said second intermediate chamber, and extending down through and being secured to said fourth tube sheet,
• a third plurality of third tubular centrifugal separator units all of the same predetermined size in said third station having open, tubular, first upper ends in communication with said second intermediate chamber, and extending up through and being secured to said fifth tube sheet and having open, tubular, second lower ends in communication with said outlet, and extending down through and being secured to said sixth tube sheet,
• said separator units each including an outer tube and each including an inner tube of smaller O.D. than the I.D. of the outer tube and positioned concentrically within said outer tube defining an annular channel extending downwardly between said inner and outer tubes, the lower end of said annular channel being closed, said inner tube having openings near the lower end of said annular channel, said openings defining a plurality of passageways from said annular channel into the interior of said inner tube, said inner tube being closed at the top and being open at the lower end thereof, which extends down below the closed lower end of said annular channel, said outer tubes of said first, second and third units extending up through said first, third and fifth tube sheets, respectively, and being secured thereto, and said inner tubes of said first, second and third units extending down through said second, fourth, and sixth tube sheets, respectively, and being secured thereto,
• the units in the first, second and third stations, respectively, having means of prescribed geometries for causing successively stronger centrifugal separating action in particulate-laden gas for separating successively smaller sizes of particles from such gas admitted into the vessel at a given velocity and pressure, and conducted through said vessel,
• said closed lower ends of said annular channels of said first, second and third units being in communication, respectively, with said first, second and third particle discharge chambers, for conducting separated particles together with a minor percentage of bleed gas from said annular channels into said respective particle discharge chambers, further including
• first, second and third conduits communicating with said first, second and third particle discharge chambers, respectively, and leading out of said vessel for conducting therefrom first, second and third streams of bleed gas and separated particles;
• wherein
• particle-laden gas admitted into said vessel is centrifuged in each of said first, second and third stations, successively smaller particles are removed from the gas in the first, second and third particle discharge chambers, respectively, and such gas is conducted, serially, from said inner tubes of said first station, through said first intermediate chamber, to said outer tubes of said second station, through said inner tubes of said second station, through said second intermediate chamber, to said outer tubes of said third station, and from said inner tubes of said third station to said vessel outlet.