PatentedA sept. 24, 1946 f, , 2,408,250 UNITED sTATEs >115.gifENT ÍoFFlcr., oYcLoNEDUsT COLLECTOR f .Joe Crites, Evanston, Ill., assigner to'Colnbus'- ` >tion Engineering Company, Inc., New-York, N. Y., a corporation of Delaware ' Application January 26, 1944,*seria1No. l519,763 1 y This invention relates to certain new and use 2 v hold a fixed position. y*On the contrary, itwhips ful improvements in cyclone dust collectors and has for itslprin'cipal object Ythe provision of im or thrashes about within the restricted lower end , of the casing and picks :up the precipitated dust from the outer spiral near the wall of the col lector. This dust is, therefore, held in the low pressure ’spiral and carried out of the separator proved constructions whereby a large percentage of .the dusty maybe removed vfrom dust laden air in-al cyclone separator. A cyclone separator of ordinary construction casing with thev discharged air. includes rarcylindrical upper portion and a lower One of the principal objects> of the present in conicalportion which terminates in adischarge vention isto provide a new and simpliñed con spout. j The dust laden air is introduced -into the 10 struction for’recapturing thedust picked up by cylindrical- upper portion of the separator at a the low pressure inner spiral of vair which is -with- . tangent tov the inner surface thereof. The whirl- ` `>in the outer or dust precipitating spiral of a cy ing of the air forms within the -casing two con centric spirals. The outer spiral` has a'higher A further objectîis- to_accomplish the. above pressure and moves downwardly toward the apex 15 specifiedl objects‘fby means of ya by-pass which clone of the separator. It functions to Vprecipitate the ,_ y ` - - f i end of the separator so that it will b'e I'eprecipi tated in the separator and thereby make it prac 20 ticable ïto remove substantiallyrall dust from the >The dust particles carried in the air, `o_l" the - Vair in a -sin'gle_'separator. o A outer spiral lare .thrown .outwardly toward the A preferred embodimentv of the/invention is il-I side ofY the casing, while the air, _cleared ofthe lustrated in the accompanying drawing, wherein: dust, moves tangentially inward toward the ver _ Eig.„ll_i'_s ayertical'section taken through the tical axis of the separator to form the inner low 25 cyclone separator constructed in accordance with pressure spiral which, as previously mentioned, this invention; and , , 'y moves upwardly and discharges the air through i ._Fig. 2 is a fragmentary sectional view taken a central opening in the upper4 portion of the on line 2,-2 of Fig. 11. _ _ ’ . ' I , casing. j The’ separator herein shown is of the cyclone The dust particles carried ¿in the air of the 30 type and >includes a 'cylindrical upper portion I0 outerspiral and thrown outwardly toward the wall ofthe >separator casing create a dust strata which has its maximum density adjacent the wall of the separator. This dense strata maybe _rela and akconical lower portion II. The lower end is closed by a revoluble discharge valvev I2, »posif tioned in a] discharge spout structure I3.V The valve, it> wilLbe'notedL is of such construction as tively thin inithe upper portion of thefcasing 35 topermit the discharge of Vvmaterial from the cas because of its greater diameter, but the thicknessv ing butwill" prevent. the entrance ofv air into the of the V'strata increases as it moves downwardly lowerv end of the casing. Y ,_ " . " , with the outer spiral >into the restricted lower portion of the cone-shaped collector. Y,Cnlor'iseà » interceptsjthejdust picked vup by the said'low pressure. inner spiral and redelivers it to the inletv dust'from the air. The inner spiral has a lower pressure >and moves vupwardly within the casing. Its function is to discharge theair from the sepa vrator l after. the- dust has" been removed. separator. [Atthe upper end of the separator is an air exit piper I4l„`which extends downwardly a sub-y quently, at the lower portion of the collector, the 40 stantial distanceinto the upper end ofthe cas inner or less dense portion of the dust strata is ing.' 'The said 'exit pipe is arranged to be con brought into vcloser relation _to the ,boundary of centric withnthe. axis of the separator and con the inner'low pressure spiral, whereby >variations ¿nectstwith‘an air _discharge pipe I5. The dust inA .air pressure, or otherrvariable influences may isintroducedinto the cylindrical upper cause portions of this suspended dust to be ydrawn 45 ladenair, portion of the 'casing through a conduit I 6 which into the said inner spiral and` thereby carried cormniuni'pates'A with the separator casing'through out> of thev separator with the discharged air. a -.wide nozzle lI'I offordinaryv construction so as However, the dust lost4 from a cycloneV separator to'Íim'p'art .to the 'dustladen air a whirling move is not necessarily confined to dust held in sus nient within >the.separatori casing. „ Theflow pat# pension inthe above manner. On thecontrary, 50 tern formed by the air within the casing con much of theïdust lost from a cyclone separator sists of an outer spiral substantially as indicated Vmay have been previously Vprecipitatedrfrom the f by the feathered arrows. This spiral moves air and then subsequently picked up by a stem ldownwardly from the inlet toward the discharge ylike suction column formed at the lower -end of end of the casing; The whirling motion of the the inner spiral. This stem-like column does not 55 air serves to throwl the dust particles outwardly 2,408,250 3 toward the casing so as to form a dust strata which has its maximum density adjacent the wall of the separator and moves downwardly along hood where this dust, together with the dust picked up by the stem-like column I9, is deliv ered by conduit 20 into the inlet end of the sepa the inclined wall of the casing into t'he restricted lower neck of the casing substantially as indi cated by the dotted film of dust material shown at I3 in Fig. 1. rator casing. With the present embodiment of the inven The air, separated from the dust particles, moves inwardly to form an upwardly moving inner spiral, the greatest diameter of which con- _ forms to the diameter of the air exit pipe I4. This inner spiral of air is of lower pressure than 4 being precipitated, to draw the dust agitated by the inner spiral of air downwardly beneath the Y the outer, or dust precipitating, spiral and ter minates at its apex in a stem-like column I9. Inasmuch as the diameter of the upper portion tion there will be a constant discharge of dust laden air through the central conduit 20, but it is returned to the conduit I 6 and reintroduced with the other dust laden air into the inlet end of the separator. The air that is discharged through the air conduit I5 is substantially free of suspended dust particles. Tests, in this regard, have shown the improvements of the present in cention which, when applied to a cyclone sepa of the casing is relatively large,r the dust strata rator, will recapture approximately two-thirds formed in this portion of the casing is relatively of the dust which would otherwise be lost, thin. However, it increases in thickness toward I claim: the lower end of the separator. Consequently l. A cyclone separator comprising, in combi there is a strong tendency for the dust, particu 20 nation, a conical separator casing having a cen larly the less dense portion of the strata, to be trally arranged air discharge in its upper end, picked up by the inner spiral. In addition to the means including an inlet conduit for introducing dust picked up by the inner spiral inthe Zone dust laden air into the upper portion of the cas where the inner andk outer spirals meet, the ing tangentially to the inner surface thereof to whipping about of this stem-like column within form a downwardly moving dust precipitating the restricted area of the separator casing has outer spiral of air and an upwardly moving inner a pronounced tendency to agitate the precipi concentric spiral ofV air being discharged, and tated dust in the restricted lower end of the means comprising a vertically disposed inter casing so that this dust will rbe picked up and ceptor conduit varranged concentric to the sepa held in suspension in the inner low pressure spiral - rator casing and extending upwardly through the of air and carried out of' the casing through -the casing and said discharge to the exterior of the exit pipe I4. casing and provided at its lower end with an in In order to overcome this -objection the present verted hood of greater cross-sectional area than invention includes the provision of a suction con said conduit and positioned with its open lower duit which extendsdownwardly through the sep- -‘ end portion vin close relation to the restricted arator in alignment with the axis thereof so that lower end of the separator and said conduit com »the dust, set inmotion at the zone where the municating at its other end with the inlet end inner and outer spirals meet and by the said of the separator, a fany interposed in said inter stem-like column I9 of the low pressure inner ceptor conduit whereby dust suspended in said spiral of air, will be drawn upwardly through the inner spiral of air at the lower portion ofthe said conduit 2D by the action of a fan 27|, inter separator is intercepted by said hood and directed posed in the said'conduit, and delivered into con through said interceptor conduit to the inlet con duit I6, whereupon it is returned to the inlet end duit of the separator. of the separator to be again precipitated from 2. A cyclone separator comprising, in combina the air. tion„a conical separator casing, a centrally ar Preferably, the conduit 20 is composed of two ranged ai'rr discharge pipe extending into the up sections, the upper section being fixed to the air per end of the separator, means for introducing pipe I3 by any suitable means,4 for example, a dust laden air into the upper portion of the cas ñashing 22. The lower end of the «said conduit U ingV tangentially to the inner surface thereof. to 20 is designated by the reference numeral 23 and form a dust precipitating outer spiral of air and is adjustable relative to the fixed section 20. The a. low pressure inner spiral for the air being dis lower end of the adjustable section 23 is provided charged, a centrally disposed by-pass conduit for with a suction hood 24. of greater diameter than conducting dust particles suspended in the lower the conduit and is arranged with itsV open end portion of _the separator to the dust inlet of the downwardly, Preferably the diameter` of the " separator, the said by-pass conduit including an hood is equal to approximately one«half of the upper section rigidly mounted on the upper end air exit pipe I4. The said adjustable section is of the separator, a rod adjustably suspended from supportedby means of a rod 25 which extends out of the conduit 20 at the bend 26 thereof. Preferably a flashing 21 is provided with a collar 28 through which the upper end of the rod 25 extends. The said upper end of therod isfpro vided with a series of apertures 29, through which a cotter key 3l!> may be inserted to support the rod and the hood 24 in any predetermined ad justed position. By raising and lowering the acl justable hood section of the conduit 20„it can. be positioned in such locations- that it will function, under different pressures. and volumes of dust the upper endof the by-pass conduit, a lower section slidably supported within- the upper sec tion of said 'conduit connected to the lower end of said rod and formed with a downwardly open ing hoodV of greater cross-sectional area than the said upper section, wherebythe position of the hood may be adjusted relative to the wall of the restricted lower end of the separator to vary the air pressures at the lower ends of the concentric spirals of air within the casing. JOE, CRITES.