Dec. 31, 1946'. 2,413,499 c. s, HuLToN UNIT` DUST COLLECTOR Filed April ’7, 1945 3 Sheets-Sheet l // INVENTOR » ö/Zar/es óï/z’zz/íofz BY ` v ATT’YS - Dec. 31, 1946. C, s, HULTON 2,413,499 UNIT DUST COLLECTOR ' Filed April 7, 1945 i 3 sheets-sheet 2 N .59 u1l/1l ,20 /0/72 40 Dec. 31, 1946. I 2,413,499 Q_ $_ HULTON UNIT DUSTl COLLECTOR Filed April '7, 1945 5 Sheets-Sheet 3 62 30 5/ Q_____. IN VEN TOR Char/6s 6I /z'u/Íon BY 2,413,439 Patented Dec. 31, 1946. UNITED STATES y PATENT OFFICE - 2,413,499 ’ UNIT DUST'COLLECTOR Charles S. Hulton, Cincinnati, Ohio, assìg'no'r ’toV ~yi‘he Kirk & Blum Manufacturing Company, Cincinnati, Ohio, a corporation of Ohio Application April 7, 1945, Serial No. 587,114 9 Claims. (Cl. 18S-36) 2 1 The present invention relates to unit dust col lectors adapted for use in connection With one or several dust producing machines where a large system of dust collector trunk and branch pipes is undesirable or unnecessary, An object of the invention is to provide a unit dust collector which occupies a minimum of floor space and which may be housed under a very low work shop ceiling. A further object of the invention is to provide a unit of this type which is exceptionally ei‘licient as well as extremely compact. and an upper compartment I6, The lower com partment I5 houses a suitably mounted suction fan i60 and an electric motor Il connected there-~ to. Compartment i5 is closed by a removable panel I8 with suitable screened Ventilating slots I9. The motor is desirably connected directly to the fan by a shaft 2li. The outlet conduit 2l of the fan extends vertically upwardly through a hole in the intermediate bulkhead I3 and thence through a registering hole in the top bulkhead iii and upwardly therefrom to an elbow or turn 22 which connects tangentially with the circumference of the upper cylindrical portion 23 of a A further object of the invention is to provide centrifugal dust separator indicated generally as a primary dust separator housed within and op eratively connected to a simple and inexpensive 15 24. The horizontal top 25 of the centrifugal sep arator 24 is a circular plate through which the dust filter of large capacity whereby to usefully air outlet 23 of said primary separator opens. employ all of the space occupied by the device. Plate 25 is disposed concentrically with the base Still another object of the invention is to pro« IU and the outlet opening 26 and also the fan vide a device of this character that is arranged for easy and automatic cleansing of the second 20 discharge conduit 2l are thus eccentrically posi tioned with respect to plate 25. The primary ary dust ñlter and for the return of accumulated separator 24 has its dust outlet 2ï extending secondary dust to the primary separator for ul» timate deposit in the main waste receptacle with- ' out the necessity of shutting off the air flow through the device. n These and other important objects are attained by the means and'method herein described and exempliñed in the accompanying drawings in which: J Fig, 1 is an elevational View of a unit embody ing the invention. Fig. 2 is a cross-sectional view taken on line through a hole in the top bulkhead I`4 and its in verted truncated conical portion 28 is rigidly 25 supported intermediate its top and bottom by means of a truncated conical brace member 23. It will be understood that the connections be tween the several metal parts'may be secured by spot Welding or other known means as desired. 30 The top bulkhead I4 is arranged to` provide a narrow circumferential cleaning'slot 30 having sharply inclined> side walls 3| and 32, the former of which is provided by a downturned lip on the casing I0 while the latter is constituted by an opposed downturned lip or íiange on the bulk 3-3 of Fig. 2, part being broken away. 35 head. The bulkhead is supported from beneath Fig. 4 is a cross-sectional vieW taken on line and insidethe flange 32 by the top edge of wall 4-4 of Fig. 1. 33 of a cleaning channel 34 into which the slot Fig. 5 is an enlarged, cross-sectional view taken empties. The bottom'wall 35 of cleaning chan on line 5-5 of Fig. 1. Fig. 6 is a cross-sectional view taken on line 40 nel 34 is welded to the inner circumference of base IIJ and thus forms a rigid connection to and 6_6 oí Fig. 3. ` support for the top bulkhead I4. Cleaning chan Fig. 7 is an enlarged, cross-sectional view nel 34 is of uniform width and extends entirely showing the mounting of a ñlter member of the around the inside of the base. The bottom wall device. Fig. 8 is a fragmental, top plan view of draw 45 35 of channel 34 inclines in both directions from one point 36 so that the capacity of the channel band and its clamping means forming a detail of increases around the circumference to a directly the invention. opposite point where the channel 34 connects The unit dust collector of the invention as With a cleaning outlet port 31 from which a rec herein embodied comprises a base I0 suitably ar ranged for securing to the floor by means of 50 tangular pipe connectionV 38 extends outwardly and downwardly to a rectangular valve .cham bolts IIv passing through a base flange I2, and ber 39 which communicates at one side `with the said base I0 preferably takes the form of a rigid fan casing suction inlet 4B. Anyv desired dust cylindrical housing of -sheet metal having an in producing machine (not shown) is connected by termediate bulkhead I3 and top bulkhead I4 de suitable pipe such as 4I to the opposite.'side of ñning, within the'base, a lower compartment I5 2--2 of Fig. 1. ' Fig. 3 is a cross-sectional view taken on line 2,413,499 3 4 valve chamber 59. A valve damper 42 is pivoted as at 43 so that it may be selectively moved by a hooked keeper 65 fastened on one end of the external valve lever 44 to assume a normal posi tion as shown in full lines in Fig, 3 wherein com munication between cleaning channel 34 and the suction fan is completely cut off so that the suc tion from a waste producing machine passes through the fan and through outlet pipe 2l and into the primary dust separator 24 in the normal manner. The primary dust separator is of relatively strap 63 and a complementary member compris ing a link 56 pivoted at one end to a bracket Gl' fastened on the remaining end of the strap 52. The free moving end of link 55 is pivoted inter mediate the ends of a lever member 5l, the end 58 of which may enter and leave the keeper 55 freely when said lever is moved to an outwardly extending position. When the lever is pushed to a substantially flush or parallel relation with the strap, the keeper 55 is moved toward the small diameter and is highly eñîcient so that all of , bracket 58 thus drawing the ends of the strip to the heavy materials and a. very high percentage of ‘gethen the ñne dust brought in through pipe 4l will be The end 59 of the outer ñlter or back 52 is dropped through the dust outlet port 27 of the 15 likewise made of suitable ñlter cloth and it is separator and into a receptacle 45 in the 4upper desirably provided with a reenforcing patch 1B compartment l5 of the base. In the present em directly over the air outlet 26 from the primary bodiment the upper compartment has a pair of separator. doors 45 and 4l jointly governing a large door The operation of the device vis as follows: It opening 48 in the upper compartment, said doors 20 will be assumed that pipe 4i is connected with a having screen Ventilating openings 49 therein and dust and waste producing machine which would being hinged at the sides 50 and 5i of the open normally be located closely adjacent the unit dust . ing. The free edges of the doors 45 and ¿il meet collector of the invention, and that the damper at 52 and are retained `in closed position by a or valve 42 is in the position shown in Fig, l latch structure 53, the complementary parts of 25 and closing off communication between pipe 33 which are carried by the respective doors. In the present embodiment the waste receptacle 45 and valve chamber 39. When the motor Il is energized, fan I6 will draw a large Volume of air is a bag of heavy ñlter cloth the mouth of which is releasably connected over the mouth of a de at high velocity through pipe 4l through the fan case and thence outwardly through pipe or pending circular iiange 54 which surrounds the 30 conduit 2l into the top of centrifugal separater dust outlet 2l. It will be noted that the dust 24. This primary separator functions in known receptacle or bag 45 functions as a dust filter manner to expend the energy of the dirty air during the accumulation of waste which drops stream in circular motion within the separator, through dust outlet 27 of the primary separa-tor, thus causing all heavy materials and a very high since air may readily pass from the interior of the percentage of the ñne dust to travel downward bag, through the porous wall thereof, the unìllled ly and drop out of the dust port 2l of said primary space in upper compartment i5 and thence separator and into the receptacle 45. The sub through the screened slots ¿S in the doors. The stantially clean air carrying only a small per fan outlet pipe 2l passes through the upper com# centage of the original ñne dust content of the partment and as the bag 45 fills it will shape itself 40 air now passes outwardly in the direction of the around said pipe and any other obstacles therein solid arrows into the space between plate 25 and and become ñrmly packed with waste as it ac» the end 69 of the outer filter, whereupon the air cumulates. begins to pass first through the pores of end 55 As can «be best seen in Figs. 5 and 6 a pair of and then through the pores of the entire sur air escape conduits 55 extend from the top bulk face area of the outer filter 62, and as said air head i4 to the wall of base I5, these are each enters the annular space between inner filter provided with a screen _55 which is desirab-ly 55 and outer ñlter 62, the air also passes through located closely adjacent the plane of the base the pores of said inner filter 59 into the space wall Hl. Referring again to Fig. 5, a channel _between it and the exterior of the primary shaped ñange 5l is secured on bulkhead .E4 im 50 separator from whence it escapes to the at mediately adjacent the downturned flange 32. mosphere through air escape conduits 55 and A corresponding channel-shaped flange 58 is screen 56. This air is thus thoroughly cleaned secured on the bottom of plate 25. The mount and is discharged into the room or Shop without ing flanges 51 and 58 are concentric and of equal any hazard to the health of the occupants. diameter and they form means for receiving the 55 It will be appreciated that the ñne dust re opposite ends of a tubular inner filter member 5S maining between the filters 59 and 62, though very which thus isolates the space between itself and limited in quantity, will eventually accumulate the primary separator 24 including its inlet pipe and begin to impair the efñciency of the ñlter. 2l from the outer atmosphere except through air That portion of the ñlter dust which drops to the escape condiuts 55. On the outer circumference 60 slot 30 may pass into the channel 34 and accumu of base I0 immediately adjacent the downturned late there. When the filter is to be cleaned of lip or flange 3l is an annular grooved iiange 50 dust, the damper 42 is moved from the position over which the mouth portion 6I of an inverted shown in full lines in Fig. l to the dotted line cylindrical ñlter bag 62 is passed. position as indicated, whereupon the suction The mouth of the dust bag 45, the mouths at through pipe 4l is shut off and the air is now opposite ends of inner ñlter member 59 and mouth caused to recirculate through the path indicated 60 of the outer ñlter member or bag 62 are re~ by broken arrows from valve chamber 39 through tained on their respective grooved flanges by any the fan, through pipe 2l and thence through suitable encircling membenvwhich in an emer ' the primary separator and through the space gency may be simply a cord (not shown) tied 170 between the filters 59 and 62 and into the chan tightly into the groove in the preferred form. nel 34. The air is drawn from channel 34, The securing is eifected by a flat flexible securing . through the port 3l and intov the by-pass pipe 38. strap 63 of a length to accommodate the diameter Due to the diminishing cross-section of channel of the- selected channel ñange and provided at its 34 from its port 31 to the point 36 remote from opposite ends with a draw clamp £4 made up of 75 the port,.the recirculatedair passes through slot 5 6 30 at uniform velocity throughout its circumfer- separator supported on~ top of the bulkhead and having a dust outletv at the bottom extending downwardly through said bulkhead into the base, said separator comprising a top plate providing an air outlet at the top of the separator and ence and the velocity of the recirculating air is thus kept substantially uniform throughout the filter. While the air is thus being recirculated the loosely adhering dust will readily be entrained in the recirculating air stream and again a high percentage of that accumulated dust will be de posited in receptacle 45 by the normal action of the primary separator. . overhanging a substantial portion of the bulk head, a tubular filter member connected at its top to said plate and atv its bottom to said bulkhead in wardly ofY the periphery of the bulkhead and en The inner faces of the filters become soiled 10 circling said separator in closely spaced relation, an inverted ñlter'bag having the mouth portion with accumulated dust represented by the small removably secured peripherally to the periphery percentage of material that is not removed by the of said bulkhead and enclosing said tubular filter primary separator. This dust within the lil-ter member in :closely spaced relation, the air out is desirably removed frequently enough to avoid let of the primary separator discharging into the impairing the efliciency of the unit.` The removal space between said top plate and said ñlter bag of accumulated dust in the bottom and on the and an >elbow conduit passing in non-communi walls of the ñlter is accomplished simply and in cating relation through the interior of the base an automatic manner without shutting off the and venting the space between the exterior of power and without shutting off the air flow from the primary separator and the interior of the the fan to the primary separator. With the unit tubular filter member to the atmosphere~ in operation it is necessary only to manipulate 2. In combination a rigid casing having an in valve 42 between its opposite limits a few times termediate bulkhead and a top bulkhead forming in order to clean the filter and deposit practically7 -a pair of compartments therein, a motor and fan all of the removed dust in the dust receptacle 45. unit mounted in‘said lower compartment, said While the unit is in normal operation, the pipe fan provided with an inlet rextending through the 4I and the usual hood of the connected machine wall of, said rigid rcasing and having an outlet beyond (not shown) account foran appreciably >duct extendingupwardly through the bulkheads large fraction of the total resistance in the air of said casing, afprimary dust separator sup flow circuit and it thus rather definitely deter mines the number of cubic feet of air per minute 30 ported on the upper bulkhead and extending above said rigid casing and having a dust outlet constantly entrained in the circuit and being dis at its bottom passing downwardly into the upper charged to the atmosphere through 'the filter compartment in said rigid casing, a waste recepta walls at a given rate through each square foot cle in the upper compartment and removably con of filter’surfaces. When- valve t2 is closed to nected to said dust outlet, a conduit connecting shut off pipe 4 I, the aforesaid fraction of the total the fan outlet with said primary dust separator,r normal resistance is lost and the operating char a tubular filter member supported at its top by acteristic of the motor, fan and primary sepa said primary separator and at its bottom with said rigid casing and forming an air relief space handle a proportionally greater number oi cubic feet of air perminute. As pipe 38 was opened 40 between the primary separator and itself, an inverted ñlter bag connected at its bottom to the the entrained air in the unitvis recirculated and rigid casing and disposed in outwardly spaced re the entrained air ñows through the space be lation to'said tubular ñlter'casing, the space be tween the ñlter walls. The improved operating tween the 'said filter members being in communi characteristic or fan capacity in C. F. P. M. how- , ever must be satisñed by an inrush of atmospheric 45 cation withA the air outlet of said primary separator. air through every square foot of the filter sur 3. In combination a rigid casing having an in faces in a matter of a second or two of time. termediate bulkhead and a top bulkhead forming The velocity of this inrushing air is higher and a pair of compartments therein, a motor and fan its direction is reversed to that of the normal ñltering operation. Hence for a brief interval the 50 unit mounted in said lower compartment, said ian provided with an inlet extending through the ñlter cloth is subjected to a pressure or velocity wall of said rigid casing and having an outlet ex air cleaning and a slight agitation. The adhering tending upwardly through the bulkheads of said and lodged dust particles are thus liberated and casing, a primary dust separator supported on taken into the circulating air stream and a very high percentage of this dust is taken out by the 55 the upper bulkhead and extending above said rigid casing and having a dust outlet at its bot primary separator. By successively opening and tom communicating with the upper compartment closing pipe 4I and thus alternately and auto in said rigid casing, a conduit connecting the fan matically changing the conditions as aforede outlet. with said primary dust separator, a tubular scribed a thorough automatic cleaning of the ñlter members and the ñlter trough is effected. The 60 dust filter supported at yits top by said primary separator and at its bottom with said rigid cas volume of air gained cleans the filter and is ing and forming an air relief space between the cleaned by passing through the primary sepa primary separator and itself, an inverted dust rator. When the gained volume is lost by a filter bag connected at its bottom to the rigid return to normal operation of the unit, that loss is in the form of cleaned air passing through 65 casing and in outwardly spaced relation to said tubular dust ñlter member, the space between the filters to the atmosphere. the said dust filter being in communication with It is to be noted that any other type of primary the air outlet of said primary separator and a separator may be employed in lieu of the cen conduit extending through the top bulkhead, the trifugal separator as illustrated, and it is further to be noted that ¿the unit is subject to minor varia« 70 upper compartment and the outer Wall of the rigid casing for venting the air relief space be tions, within the spirit of the invention and the scope of the appended claims. tween the tubular dust filter member and the separator to free atmosphere. What is claimed is: 4. In a unit dust collector the combination of .1. A unit dust collector comprising a hollow base having a top bulkhead, a primary dust 75 a hollow rigid base having an upper compart rator is instantly and automatically changed to 2,413,499 8 7 and having an air outlet at the top of said primary dust separator, spaced concentric filters form ing a cover for the primary dust separator and secured at their bases to the top of said base compartment, the space between said filters communicating with the air outlet of the pri ment and a lower compartment in non-com municating relation therein, a power driven dust collector fan in said lower compartment and hav ing an inlet extending through the side wall of the base casing and an outlet duct extending up wardly through the lower and upper compart ments, a primary dust separatorsupported on the top of said base and having an inlet connected mary dust separator and means comprising a with said fan duct and having a. dust outlet com munication between the space intermediate said municating with the interior of the upper com valve controlled pipe to selectively effect com 10 filters and the inlet of primary dust separator. partment, said primary dust separator having an air outlet at its top, a pair of relatively closely spaced, nested dust filters extendingdownwardly over andr encircling the primary dust collector, the space between said dust ñlters being in free v communication with the air outlet of the primary dust separator, and a dust storage receptacle re movably secured about the dust outlet of the pri 7. An air recirculating dust collector unit com prising a primary dust separator having an air inlet, a dust outlet and an air outlet, a pair of spaced concentric ñlters the innermost of which envelopes said separator and has the air outlet passing therethrough, a dust receptacle remova bly connected to said dust outlet, means connect ing the filters at the bottoms thereof and form mary dust separator within the upper base com ing a settling channel, and means selectively con partment. necting the interior settling> channel with the air 5. An air recirculating unit dust collector com prising a base compartment, a primary dust sepa rator mounted on the top of said base compart ment eccentrically thereof and having a dust out let communicating with the interior of said base compartment, and having an air outlet at the top of said primary dust separator, a pressure inlet of said separator. fan outlet duct extending upwardly .through the top of said base compartment alongside said 8. In a device of the class described the com bination of a primary separator having an inlet, a dust outlet at its bottom and an air outlet at its top, a suction fan disposed below the separa tor and having an upwardly extending outlet duct connected with the inlet of said separator, said ian having an inlet duct for connection with a dust producing device, a removable waste re separator and connecting tangentially with said . ceptacle interposed between the fan and the separator adjacent its top, an inner tubular filter forming a cover for the primary dust separator and secured at its base to said base compartment, plate means at the top of the separator having the air outlet thereof passing through it and peri pherally connected with the top end of said ñl ter, an inverted ñlter bag peripherally secured at its mouth to the circumference of said base at the separator and connected to the dust outlet, a set separator and duct, a pair of spaced ñlters ex tending upwardly from opposite sides of the set tling channel and together forming an enclosing cover for the separator and duct, the air outlet top thereof, enclosing and in outwardly spaced controlled, Icy-pass conduit connecting said chan tling channel surrounding the bottom of the of the separator discharging into the space be tween the ñlters, and means comprising a valve relation to the inner filter and the top of the 40 nel and said inlet duct of the fan. 9. In a unit dust collector the combination of separator whereby outlet air from the separator a power driven suction fan having an inlet duct may be dissipated through the inner filter and and an upwardly extending outlet duct, a pri the filter bag, conduit means extending through mary separator mounted alongside said outlet the interior of the base compartment and ar duct and labove the fan, the separator having an ranged to vent the space within the inner tubu inlet connected with the outlet duct of the fan lar ñlter to the outside of the base compart and further having a dust outlet at its bottom ment, a removable waste receptacle within the and an air outlet at its top, spaced filter members base compartment and connected to the dust out surrounding the duct and separator and enclos let of said separator, and a power driven collector fan housed within said base compartment con 50 ing a filter space, the air outlet of said fan dis charging into said ñlter space, an annular set necting with the outlet duct therein, said fan . tling channel forming a bottom connection for having its suction inlet extended to the exterior said filters, a by-pass duct connecting said chan of the compartment for connection with a clust nel and the fan inlet duct, and a valve disposed producing means. at the junction of the fan inlet duct and the by 6. An air recirculating unit dust collector com pass duct for selectively connecting the fan with prising a base compartment,` a primary dust said by-pass duct and said inlet duct ahead of separator mounted on the top of said base com partment eccentrically thereof and having an in let for dust laden air, a dust outlet communicat ing with the interior of said base compartment, 60 said by-pass duct. » v CHARLES S. HULTON.