US1910829A - Separating apparatus - Google Patents

Description

May 23, 1933. s. GREEN 1', 910,829

SEPARATING APPARATUS Filed Nov. 7, 1930 IN V EN TOR. j 24 fi/yae'waoa Giff/Y.

A TTORNEYS.

Patented May 23, 1933 UNITED STATES PATENT oFFIcE snnnwoon GREEN, BERKELEY, C IFORNI ASSIGNOR r0 AMERICAN ooir'roN' MACHINERY 00., on BERKELEY, CALIFORNIA, A CCJRPORATION OF NEVADA SEPARATING APPARATUS Application filed November 7, 1930. Serial No. 494,057.

,continuous separation between the cotton and the carrying or conveying stream of air. A common method of effecting this separation has been to direct the stream of air carrying the cotton against a stationary inclined screen, whereby the air passes thru 2 the screen to the exclusion of the cotton. In order to prevent blocking of the screen with the fiber, which would prevent continuous operation, suitable wipers have been employed to sweep over the surface of the Q5 screen against which the stream of gas is directed. Prior apparatus and methods of this character have been subject to certain disadvantages. For example the wipers have not always been effective to prevent 3 blocking of the screen, thus causing an impairment of efficiency or even causing occasional shutdowns. The chief difficulty however has been that such a separator tends to cause roping of the cotton fiber, thus a5 placing it in such condition as to make further treatment or milling operations difficult. While the causes of roping are diflicult to analyze, I attribute it mainly to the fact that in such prior apparatuses the cotton fiber carried by he air stream is propelled directly into contact with the separating screens, and also to the action of the wipers. I

It is an object of the present invention to devise a separating apparatus of the above character which will maintain relatively high efficiency for continuous operation, and

whichwillnot cause roping when used with cottonfiber. p

It is a further object of the invention to devise a separating apparatus which funct1ons automatically to prevent blocking of the separating screen, without theuse of mechanical wipers.

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth in detail in conjunction with the accompanying drawing. It is to be understood that the appended claims are to be accorded a range of equivalents consistent with the state of the prior art.

Referring to the drawing: c

Figure 1 is a side elevational View of the apparatus incorporating the present invention.

Fig.- 2 is a cross sectional view taken along the line 2-2 of Fig. l.

The particular embodiment of the invention illustrated in'the drawing consists of a housing 10, made of suitable material such as sheet metal, and which is adapted to be connected with a pneumatic inflow conduit 11, and a pneumatic discharge conduit 12. Positioned within the upper portion of housing 10 there is a perforate screen13, which is preferably in the" form of a sub,- stantially cylindrical drum. Wire mesh having apertures of about th inch square has been found practical. The end plates 14 of the drum formed by screen 13, can be imper'forate, and are mounted upon a horizontal rotatableshaft 16. Suitable journals 17 are indicated for shaft 16, and a. suitable driving connection is represented by pulley 18. l

-The inflow opening 19 in housing 10, which communicates with inflow conduit 11,

preferably extends substantially the length 7 of screen 13, and is shown connected to conduit 11 'by. the flared or divergent conduit section 21. The outflow or'discha'rge opening 22, which communicates with. discharge conduit 12, can be conveniently located at the top of the housing as shown in Fig. 2 and likewise preferably extends substantially the length of screen 13. For the lower portion of housing 10, it is desirable to form the side walls 23 and 24s convergent as shown in Fig. 2, and these walls serve in part to define what can be termed a collecting chamber 26. The lower end of the collecting chamber is shown provided with a flange 27 to facilitate making connection with a conduit or other suitable means for removing the separated fibrous material. In the event that the interior of the housing is maintained at a pressure differing from the pressure to which the separated cotton is discharged the material discharged from collecting chamber 26 must pass through a suitable rotary valve device, such as are well-known in the art.

While it is conceivable that the inflow opening 19 may be located at various points with respect to the housing and with respect to the screenxl3, the position illustrated in Fig. 2 gives good results. It will be noted that in this position the general axis of the stream of gas flowing into the housing is spaced below the axis of shaft 16. In other words the gas is directed towards a restricted portion of the periphery of the screen, and this portion is located to one side of the screen and below the axis of rotation. Likewise while the exact position of the outflow opening 22 can be varied a certain extent, it is desirable to have this opening adjacent the upper portion of screen 13, and above opening 19 and the collecting chamber 26. With respect to this opening 22 itwill also be noted thatthe upperhousing section 29 within which it is formed, is curved to fit relatively closely the upper portion of the screen 13.

Located below the screen 13, and within the collecting chamber 26, there is a substantially imperforate baffle or deflector plate 31. This baflie or deflector plate extends substantially the entire length of screen 13, and is preferably adjustably mountedupon the housing. For example each end of the plate i'sshown-pivotally connected to an arm 32, which in turn is slotted to receive a screw or'bolt 33 for adjustably securing the same to the end walls of the housing. Each end of plate 31 is alsosecured to a slotted member 34, which is'adjustably secured to the associated end wall of the housing by a screw or bolt 36. Thus plate 31 can be adjusted at different angles to the vertical, and also the clearance between the upper edge of this plate and the periphery of screen 13 can be adjusted.

The apparatus as described above will operate satisfactorily 'without further ele ments. However it has been found. desirable to add flexible strips 37 and 38 which lightly engage the opposite sides of screen 13.- These strips are secured to adjacent portions of the housing 10, and extend substantially the length ofthescreen.

To describe the operation of my separator it will be presumed that a forced draft of air is flowing thru conduit 11, carrying with it unginned cotton fiber. As the air stream flows into the housing 10 it strikes the adjacent portion of screen 13, and the majority of the air, to the exclusion of the cotton, flows immediately thru the perforations of the screen. The cotton is deflected downwardly and is deposited into the collecting chamber 26. The screen is continuously rotated so that different portions of its surface are progressively subjected to the stream of air. \Vhile rotation of the screen can be in either direction, it is preferable to rotate it in a counterclockwise direction as viewed in Fig. 2, and at a relatively slow speed.

The air flowing into the interior of screen 13 must flow upwardly thru a restricted portion of the screen to discharge thru opening 22. This flow of air in a reverse direction thru the screen serves the useful purpose of removing any adhering fiber. In utilizing the apparatus for the separation of unginned cotton, the majority of the fiber of the cotton is in relatively large masses, and it is this fiber which is deflected downwardly into the receiving chamber 26. However a certain amount of the fiber, commonly termed lint, becomes dissociated from the larger masses, and a certain amount of this fiber or lint tends to cling to the outer periphery of the screen. Without proper provision for the removal of this fiber, efficiency of the apparatus would be gradually impaired thru blocking of the perforations of screen 13. However with my apparatus as the screen revolves the adhering lint is carried to a point adjacent opening 22 where it is subjected to the discharging stream of air,

and thereby carried out in suspension with the air.

As has been previously stated, one of the objects of my invention is to prevent roping of the separated cotton fiber. This object is accomplished, due to the peculiar fact that the majority of the cotton fiber as it is deflected along and away from the screen 13, into the chamber 26, does not come into direct physical contact with the outer surface of the. screen. Experiments indicate that a layer or cushion of air is formed betweenthe rapidly moving fibrous masses and the adjacent portion of the screen 13. The actual physical state of this cushion of air is not thoroughly understood, but it functions to deflect the greater mass of cotton fiber without physical contact with the screen. In this connection the operation of my apparatus is distinctly difierent from prior conventional types of separating devices utilizing stationary screens, in which the cottonfiber is propelled directly into contact with the screen.

Bafiie plate 31 tends to aid in properly discharging separated cotton fiber into the receiver 26. Air from the stream entering inflow 19 which does not flow directly thru screen 13, is caused to flow downwardly in front of plate 31 and then upwardly between this plate and side walls 24, and it gradually finds its way into the interior of screen 13. Flexible strips 37 and 38 tend to prevent direct short circuiting of air from the inflow 19 to the discharge opening 22, and also strip 38 tends to position the lint fiber upon the screen in such amanner that its removal by the air stream passing thru discharge opening 22 is facilitated.

It is evident that in place of operating with a forced draft or stream of air thru conduit 11, an induced draft can be employed by applying asuction to conduit 12.

However in this event the separated fiber must be removed from chamber 26 thru suitable valve means to enable maintenance of a sub-atmospheric pressure within the separator housing, if the cotton is to be delivered to atmospheric pressure.

What is claimed is g 1. In apparatus for effecting separation of fibrous material from a conveying stream of gas, a drum shaped perforate screen adapted to be continuously rotated about a horizontal axis, a housing in the upper part of which the drum is disposed, the lower part of the housing below the screen forming a collecting chamber, means for directing a gas stream carrying fibrous material into one side of the housing toward a lower side of the screen, whereby gas flows thru the screen into the interior thereof and fibrous material is deflected downwardly towards the collecting chamber, a bafiie plate positioned within the housing below the screen, said plate eX- tending the length of the screen and depending from the lower periphery of the screen towards the collecting chamber, and means for discharging gas from the housing, said means serving to cause discharging gas to flow thru an upper portion of the screen from the interior of the screen outwardly.

2. In apparatus for effecting separation of fibrous material from a conveying stream of gas, a drum shaped perforate screen adapted to be continuously rotated about a horizontal axis, a housing in the upper part of which the drum is disposed, the lower part of the housing below the screen forming a collecting chamber, means for directing a gas stream carrying fibrous material into one side of the housing toward a lower side of the screen, whereby gas flows thru the screen into the interior thereof and the maj or portion of the fibrous material is deflected downwardly, baflie means positioned within the housing below the screen adapted to direct said major portion of the fibrous material into the collecting chamber, and

means for discharging gas from the housing, said means serving to cause discharge of gas to fiow thru a minor peripheral portion of the screen from the interior of the screen outwardly.

8. In apparatus for effecting separation of fibrous material from a conveying stream of gas, an endless screen adapted to be moved continuously, a housing in the upper part of which the screen is disposed, the lower part of the housing below the screen forming a collecting chamber, means for directing a gas stream carrying fibrous material into one side of the housing toward a lower side of the screen, whereby a major portion of said gas stream flows directly thru the screen into the interior thereof and the ma- ]or portion of the fibrous material is deflected downwardly, baffle means positioned within the housing below the screen and serving to direct said major portion of the fibrous material into the collecting chamber, and means for discharging gas from the housing, said means serving to cause discharging gas to flow thru a portion of the screen from the interior of the screen outwardly.

4. In apparatus for elfecting separation of fibrous material from a conveying stream of gas, an endless perforate screen adapted to be moved continuously, a housing in the upper part of which the screen is disposed, the lower part of the housing below the screen forming a collecting chamber, means for directing a gas stream carrying fibrous material into one side of the housing toward a lower side of the screen, whereby a major portion of the gas stream flows directly thru the screen into the interior thereof and the major portion of the fibrous material is deflected downwardly, a baffle disposed within the housing below the screen, said baflie extending the length of the screen and depending from the lower side of the screen toward the collecting chamber, and means for discharging gas from the housing, said means serving to cause discharge of gas to flow thru a restricted portion of the screen from the interior of the screen outwardly.

In testimony whereof, I have hereunto set my hand.

SHERlVOOD GREEN.

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