US2755930A

US2755930A - Tobacco and dust separating apparatus

Info

Publication number: US2755930A
Application number: US219551A
Authority: US
Inventors: Eissmann Oswald Erich
Original assignee: AMF Inc
Current assignee: AMF Inc
Priority date: 1951-04-06
Filing date: 1951-04-06
Publication date: 1956-07-24
Anticipated expiration: 1973-07-24

Description

0. E. EISSMANN TOBACCO AND DUST SEPARATING APPARATUS Filed April 6, 1953 July 24, 1956 2 Sheets-5heet l INVENTOR OSWALD ERIGH EISSMANN Mix! ATTORN EY July 24, 1956 0. E. EISSMANN 2,755,930

TOBACCO AND DUST SEPARATING APPARATUS Filed April 6 1951 2 Sheets-Sheet 2 INVENTOR OSWALD ERICH EISSMANN BMJM ATTORNEY United States Patent 2,755,930 TOBACCO AND DUST SEPARATING APPARATUS Oswald Erich Eissmann, Richmond, Va., assignor to American Machine & Foundry Company, a corporation of New Jersey Application April 6, 1951, Serial No. 219,551 Claims. (Cl. 209-139) This invention relates to an improved tobacco and dust separating apparatus.

Heretofore a number of developments have been made in this field which have been found to have a number of disadvantages in operation. It has been found that con veyed tobacco has a tendency to roll up in lumps at certain areas of the separating apparatus and after reaching a size too heavy to be supported by the air stream it falls downwardly in a big lump which is too large to be effectively separated. As a result the machine either clogs up or a good portion of the bunched material is discharged into the wrong separating chamber.

Another disadvantage has been that small diameter cyclone separators have had a tendency to clog and they have been so disposed with respect to the separator that they have not been readily replaceable to remove clogged or Worn out separators.

It is therefore an object of this invention to provide an apparatus wherein the air intake gates are so arranged that tobacco will not ball up or roll up into rolls during the processing of the tobacco through the machine.

A further object is to provide a dust separating chamber wherein there will be a more uniform and large area over which dust laden air is extracted from the dust separating chamber.

A further object is to provide cyclone separators which will have their intake ducts mounted across the entire back of a tobacco separating apparatus.

A further object is to provide a tobacco separator wherein a bank of small diameter separators are readily replaceable.

Another object is to provide an air separating passageway which will efiiciently separate stems from lamina without causing tobacco to bunch up.

A further object is to provide and associate small diameter cyclone separators with a tobacco separating apparatus which will be of such design and construction that the dust is separated along a path of travel which is sub stantially in a straight line.

' Other objects and features of the invention will appear as the description of the particular physical embodiment selected to illustrate the invention progresses. In the accompanying drawings, which form a part of this specification, like characters of reference have been applied to corresponding parts throughout the several views which make up the drawings.

In the accompanying drawings:

Fig. 1 is a sectional side elevation of the improved tobacco and dust separating apparatus,

Fig. 2 is a partial sectional end elevation, taken on line 2 of Fig. 1, illustrating the arrangement of the dust and air receiving ducts of the filter tubes at the rear end of the machine, and

Fig. 3 is an isometric view of a single filter tube.

With reference to Figure 1, the tobacco and dust separating apparatus consist of a tobacco separator housing H, a detachable dust separator unit D, and a suitable source of suction E.

In operation, the unstemmed tobacco leaves T are deposited into an inclined feed chute 10 which delivers it into the pockets of a revolving gate valve 12. The latter, by means of another inclined chute 14, feeds said tobacco into the path of suitable combs 16 secured to a revolving drum 18. Combs 16, coacting with stationary rakes 20, 21 and 23 and a plurality of spaced semi-circular serrated bars 22 surrounding said drum, cause the lamina to be torn from the stem portion of the leaves in a manner shown and described inmy copending application S. N. 51,211 filed September 25, 1948, now Patent No. 2,701,570.

Tearing of the lamina from the stem takes place when the combs 16 first engage with the tobacco leaves. tional tearing takes place when the leaves are forwarded past stationary rakes 20, 21 and 23 and serrated bars 22.

The torn tobacco and stem portion drop through the 7' spaces between the serrated bars 22 onto a continuously moving belt 24 which hurls the torn tobacco and stem pieces toward an adjustable wall 26 into the air stream entering the separating apparatus at location A. The air stream is created by the suction system E and the torn'tobacco is carried through the separating housing H by the air stream in the direction of the arrows shown' in Figure 1.

The stem portions which have been stripped clean of leaf lamina of course are heavier than the lamina and therefore offer no resistance to the lifting action of the incoming air stream. As a result the stems drop through said opening of the housing into a suitable box or recep lamina and the stem portions tacle B. The pieces of which still have some lamina adhering thereto after being thrown 01f the belt 24 are intercepted by the incoming air stream and carried upward between the adjustable wall 26 and an air stream guide plate 28 in the direction of the arrows.

The guide plate 28 serves the important purpose of re taining the velocity of the air stream and preventing the stems with adhering tobacco from being pushed by the air stream back into the space between the serrated bars 22 and belt 24.

It has been found that without guide plate 28 the velocity of the air stream, entering from a substantially narrower opening, decreases because of the larger. space between the bars 22 and belt 24 to such an extent that the stems with adhering tobacco tumble downward'agai'n and fall out of the air stream back onto the belt and the tobacco carried thereon. bulence and started to entangle the tumbling tobacco with the newly arriving tobacco which resulted in a rolling action of the entire mass.

During this rolling action the stem portions engaged with a certain amount of free lamina and created a lump or ball similar to a snowball rolling down a' hillside.

After this lump become too big and heavy for the air' stream to support and roll, it simply dropped out of the opening of the incoming air and even sometimes choked the machine.

I have found that I have overcome this difliculty by with adhering toadding guide plate 28 and the stems bacco are carried upward and are deflected backby the deflector wall 30 into the range of action of the shredding drum 18 to be reprocessed. It will thus be seen that only clean individual stems fall out of the opening A into the chute or receptacle B.

All lamina including that hurled by centrifugal force from the shredding drum 18 travels upward and around the horizontal bend 30 of the separator housing H. In-

completely stemmed tobacco is deflected back to the thresher in the manner described and claimed in my 00- 51,211 filed September 25,-

pending application, S. N. 1948, now Patent No. 2,701,570. The vertical forward Patented July 24, s

Addi

Such movement created a tur-' wall 32 of vertical shaft 34 of said housing H is provided with an air inlet door 36 which opens up outwardly and permits a predetermined amount of air to enter into the separating chamber at this point. Door 36 is made of three sections and is shown and described in my copending application S. N. 729,818 filed February 20, 1947, now Patent No. 2,643,768. This door is provided for the purpose of controlling the amount of air in the vertical shaft of the separator housing H. I have found while it serves the purpose for which is was intended the incoming air stream traveling in substantially the same direction as the original one, often reenforced the latter stream to such an extent that it lifted up everythihng in its upward straight pathincluding undesirable light weight stems.

To eliminate this undesirable action and also to avoid the occasional objectionable accumulation of tobacco on the top surface of the stationary air stream guide plate 38, another three sectional door 40 is provided. The latter is of substantially the same design as the doors 36, but doors 40 open inwardly and cause the incoming air stream to move downwardly and somewhat intercepting the up coming air stream and at the same time offsetting the air stream entering through doors 36. It is very noticeable that this combination or action of the intercepting air streams results in a very desirable turbulence with the effect of spreading the tobacco in the separator housing over a much greater area and causing torn tobacco leaves to bounce in a crisis-cross, back and forth, and up and down manner thereby resulting in a greater quantity of cleaner finished tobacco as well as a marked increase in separating efiiciency.

The pieces of lamina thus cleaned float upward and into the rear chambers of the separator housing H provided at its lowermost portion with a suitable rotating gate valve 44 which is of substantially the same design and construction as the one shown in my copending application S. N. 51,211, and which deposits the cleaned lamina onto a su'table conveyor C. The rear chamber of the separator housing H is also provided with an inclined perforated plate 46 which permits any sand or heavy dust particles to drop through the perforations of said plate into a suitable chute 48 which leads to a suitable screw conveyor 50. The accumulated material is forwarded to a suitable gate valve 52 which discharges the material into a. collector or receptacle 54. The rear portion of said rear chamber is also provided with suitable screens 56 through which the dust laden air is exhausted and which separates lint, string and feathers from the air stream in this area.

The rear wall of the tobacco separator housing is formed by the detachable mounted dust separating unit D which consists of a clean air suction shaft 61) and a dust collecting chamber 62. Within the suction shaft 60 are detachably mounted and arranged a plurality of specially designed cyclone type is provided with a tangentially arranged inlet duct 66 which at its free end is secured to a corresponding opening 69 (Fig. 2) in the front wall 70 of the unit D which, as men oned above, forms the rear wall of the seperator housing H. This arrangement has the advantage that air velocity in the separating chamber S is uniformly lowered over the entire width of the area and there is no tendency for the air stream to be directed toward any particular outlet. This has resulted in improved separating efficiency in this part of the machine.

Each dust separator 64 is therefore connected to the rear portion of said housing H. The inlet duct 66 of each dust separator 64 is connected to and blends in with the top end of a cylindrical housing 68 of the same in a tangential and spiral fashion as illustrated in Fig. 3. The cylindrical housing 68 (Fig. 3) on its lower end is provided with a conical portion 72, the open free end of which is attached to a corresponding opening 74 formed in the rear wall 75 of the suction shaft 60. Into the otherwise closed top portion of the cylindrical housing 68 dust separators 64 each of which protrudes a tube 76 held in a suitable manner in the center of and coaxial with the housing 68.

As the dust laden air enters the tangential inlet duct 66 of each separator 64 it is caused to spin around within the housing 68 in the cylindrical space formed by its outer walls and tube 76. This spinning action results in centrifugal force separating the dust from the air and the dust, being heavier, drops out of the open'conical portion- 72 of said housing while the clean air is exhausted from said cylindrical housing through the tube 76 into the clean air suction shaft 60. The lower portion of the latter is suitably connected to one or more suctionfans 80 which, through a suitable exhaust shaft 82 discharge the clean air back into the room from which it was taken. Each exhaust fan 80 is driven by a motor M as illustrated in Fig. 1.

The dust discharged from the opening of each conical end portion 72 of each separator drops into the dust collecting chamber 62 which, at its lower portion is connected to a detachable hopper 84 having a suitable screw conveyor 86 which delivers the dust to a rotating gate valve 88 which deposits said dust into a receptable 90.

The eflicient and eifective operation of the dust separators 64 lies in their unique design and arrangement. The dust after being separated from the air within the cylindrical housing 68 is permitted to keep moving and is discharged ,in substantially the same direction as it entered said housing without being guided around corners or curves. This eliminates the possibility of dust collecting and eventual choking of the dust separators which has been one of the principal disadvantages of cyclone type separator up to this moment and especially with tobacco dust.

In order to remove any dust particles which pass through the screens 56 and do not reach the separators 64 but settle downwardly along wall 70, I have provided, a collectorthrough 92 provided with a screw conveyor 94 to deliver such dust to a rotating gate valve 96 which in turn deposits the same into a suitable receptacle 98.

For cleaning, inspection and maintenance purposes, the rear wall of the dust collecting chamber 62 is provided with a door 100.

Inorder to provide the dust filter tubes 64 with an'adequate volume of air to maintain their efficiency, the top side of the separator housing H may be provided with an opening 57 to permit additional air to enter at this point. The-amount of air entering through said opening may be controlled by a suitable door 59 mounted on a cross shaft 61 carrying a worm wheel 63 meshing with a worm which is actuated by a suitable handle 67. By turn! ing said handle clockor anti-clockwise, the door 59 may be opened or closed as desired. This feature is more completely described and claimed in my copending application S. N. 51,211 referred to above.

The bank of cyclone separators forming the rear wall of the collecting chamber 62 may be quickly replaced by disconnecting the brackets 71 which secure it to the rear of the separator.

The invention above described may be varied in construction within the scope of the claims, for the particular device selected to illustrate the invention is but one of many possible embodiments of the same. The invention, therefore, it not to be restricted to the precise details of the structure shown and described.

What is claimed is:

1. A classifying apparatus for separating tobacco stems, tobacco leaf lamina, sand, and dust into separate categories, said apparatus comprising a housing, an air passageway mounted in said housing and having areas for separating out said material into different categories, an airintake opening for allowing air to enter one end of said passageway, means for delivering a supply of torn tobacco to said air passageway, one of said separating areas being connectedto saidpassageway near the air intake opening for removing tobacco stems from said torn tobacco, an

other of said areas being an expanded chamber connected near the other end of said air passageway for separating tobacco leaf lamina from said air stream, a source of suction connected to said other end for moving an air stream with suspended material through said separating areas and through a bank of small diameter cyclone separators, means for removing the separated lamina from said chamber, and a bank of small diameter cyclone separators having their intake ducts mounted at regularly spaced intervals across one wall of said chamber for effecting a Withdrawal of air from said chamber over a wide area to separate fine sand and dust from the air stream, means for collecting said fine sand and dust from said cyclone separators, and a screen positioned between said expanded chamber and said intake ducts to prevent lamina from entering said ducts.

2. A classifying and separating apparatus for separating tobacco leaf lamina and dust into different categories, said apparatus comprising an air passageway, means for delivering torn tobacco leaves to said passageway, an enlarged, walled, separating area forming part of said passageway and located at one end thereof, a plurality of small diameter cyclone dust separators having intake ducts mounted directly over a wide area of one wall of said enlarged separating area to effect a withdrawal of air from said separating chamber uniformly over a wide area of said wall, a screen interposed in said air passageway between said separating chamber and said intake ducts to prevent lamina from being drawn into said cyclone separators, and a source of suction for moving a stream of air carrying said torn tobacco leaf lamina through said air passageway, through said enlarged separating chamber and said small diameter cyclone separators to separate lamina in said enlarged separating area from the stream of air and then to separate dust from said stream of air.

3. A classifying apparatus for separating torn tobacco leaves into different categories, said apparatus comprising a housing, an air passageway formed in said housing, means for moving a stream of air through said passageway, an air intake opening formed at one end of said passageway through which air enters said passageway, a portion of said passageway extending above and below said opening, means for discharging torn tobacco leaves into said air stream at a position adjacent said opening to allow stems without lamina to fall downwardly while causing lamina without stems to be drawn upwardly, an enlarged separating chamber forming part of said air passageway, a bank of small diameter separators detachably secured to and forming a wall of said separating chamber wherein said separators are uniformly spaced over the entire surface of said wall, the intake inlets of said small diameter separators being connected directly to openings formed in the wall of said separating chamber over a wide area thereof to effect a withdrawal of air from said separating chamber over a large wall area, and a lamina separating screen positioned across the air stream at a point upstream of said small diameter separators between said enlarged separating chamber and said intake inlets of said small diameter separators for preventing lamina from reaching said separators.

4. A separating apparatus comprising a housing, an air passageway formed in said housing, means for discharging torn tobacco leaves into a vertical portion of said air passageway, an air intake positioned above said means for causing air to enter said passageway at an angle which directs the air initially towards the means for discharging torn tobacco leaves into said air passageway to prevent tobacco from being accumulated in lumps in said air passageway, a second inlet having a downwardly extending door positioned above said air intake and swingingly mounted for movement in an outward direction from said air passageway to cause air to enter said passageway from the outside atmosphere in an upward direction to assist in pushing clean lamina up along said passageway, a separating chamber connected with and of larger cross sectional area than said air passageway for removing clean tobacco leaf lamina from the air stream, a bank of small diameter cyclone separators having their intake ducts individually connected and spaced uniformly apart and having such a number of small diameter cyclone separators as to completely cover one wall of said separating chamber for effecting the withdrawal of air from said chamber over a relatively wide surface area, a lamina separating screen mounted across said air stream at a position upstream of said small diameter separators between said separating chamber and said bank of small diameter separators to prevent lamina from reaching said separators, and a source of power for forwarding a stream of air through said air passageway.

5. A tobacco separating apparatus wherein an air passageway is provided for confining an air stream to a predetermined path of travel in a housing, said passageway having a vertical portion, a tobacco discharge device mounted in the housing for delivering torn tobacco to said passageway, said air passageway including an upwardly directed duct positioned adjacent the tobacco discharge device to receive said torn tobacco discharged from said device, the cross-sectional area of the passageway being such that it is substantially uniform, and means for moving a stream of air upwardly through the duct and through the passageway at such a velocity that clean stems fall downwardly through the duct while lamina and stems with lamina are drawn upwardly by the air stream, an air intake positioned above said discharge device to direct air downwardly towards said discharge device to prevent tobacco from accumulating in lumps in front of said discharge device, a second air intake positioned above said first named intake and having a downwardly extending, outwardly swinging door to cause air to enter said passageway from the outside atmosphere in an upward direction to assist in pushing clean lamina up along said passageway, an enlarged chamber connected to said air passageway to allow lamina to settle out of said air stream, a bank of small diameter cyclone separators having their intake ducts dispersed across one wall of said separating chamber to effect a withdrawal of air from said chamber over a relatively wide surface area, and a screen positioned between said separating chamber and said intake ducts to prevent lamina from entering said ducts.

References Cited in the file of this patent UNITED STATES PATENTS 1,888,372 Bramwell Nov. 22, 1932 2,050,765 Rundell Aug. 11, 1936 2,163,833 Eissmann June 27, 1939 2,173,087 Eissmann Sept. 19, 1939 2,173,088 Eissmann Sept. 19, 1939 2,208,896 Dahlstrom July 23, 1940 2,257,552 Hammack Sept. 30, 1941 2,643,737 Bowers June 3.0, 1953 FOREIGN PATENTS 93,386 Sweden July 1. 1938