US2913111A

US2913111A - Open section louver for material separating apparatus

Info

Publication number: US2913111A
Application number: US508189A
Authority: US
Inventors: Robert E Rogers
Original assignee: HARVESTAIRE Inc
Current assignee: HARVESTAIRE Inc
Priority date: 1955-05-13
Filing date: 1955-05-13
Publication date: 1959-11-17
Anticipated expiration: 1976-11-17

Description

Nqv. 17, 1959 R. E. ROGERS ,9 1

OPEN szc'rro'u 'LOUVER Fox HATER'IAL ssmm'mc APPARATUS Filed May 13, 1955 United States Patent OPEN SECTION LOUVER FOR MATERIAL SEPARATIN G APPARATUS Robert E. Rogers, Sausa1ito, Calif., assignor to Harvestaire, Inc., Oakland, Calif., a corporation of California Application May 13, 1955, Serial No. 508,189

11 Claims. (Cl. 209-144) This invention relates to material separating apparatus in which particles of entrained material in a fluid carrier are segregated by virtue of differences in the: unit mass weights of the respective particles. More particularly, the instant apparatus comprises improvements over the apparatus disclosed in United States Letters Patent 2,638,181, 2,638,218 and 2,638,219, all owned by a common assignee.

In each of said patents, there is disclosed separating equipment adapted to receive a continuous flow of fluid having material particles entrained therein, the flow and material being subjected, upon introduction into a conical separating chamber to the actions of centrifugal, gravital and buoyant forces which are controlled so that selected components of prescribed unit mass weight of the material are allowed to gravitally descend out of the separating chamber while the remaining mixture of rejected particles and the carrier fluid are directed upwardly and out of the chamber. By way of example, if grain and its associated chaff or weeds are introduced into the chamber, the denser grain values will move gravitally out of the chamber for collection and storage, while the less dense chaff will be discharged upwardly with the carrier fluid and constitute the tailings. An important feature in said patents is the provision of a louver compiising a plurality of vane members disposed adjacent the gravital discharge opening for the heavier components of entrained material, and by virtue of such vane members it has been possible to reduce value losses in the tailings and likewise reduce the amount of tailings passing gravitally downward with the selected material components.

Unfortunately, the exact phenomena of forces, pressures and the like which effect satisfactory separation cannot be readily ascertained from either formulae or empirical data. However, it has been found that with the vane construction disclosed in said patents, the high efficiency of separation desired for such operations is not always present.

Accordingly, it is an object of the present invention to provide material separating apparatus in which a separating chamber is provided with a novel louver construction which will effectively permit separation of material particles of different unit mass weights.

Another object of the invention is to provide apparatus of the character described which is particularly adapted for separating material particles having substantially different unit mass weights, e.g., wheat and its associated chaff, and which is capable of handling large volumes of such material without jamming or otherwise impairing the efficiency of the operation.

A further object of the invention is' to provide a louver construction of the character described which is adapted to direct the heavier components of entrained material in one direction for collection, and is likewise adapted to direct the waste components of lighter consistency in another direction for discharge.

A still further object of this invention is to provide a louver having a central imperforate bafile member and a plurality of radially extending vanes with such vanes being spaced from each other to provide unobstructed vertical passages therebetween, with the area of the baffle relative to the vanes, and the area of the vanes relative to the spaces therebetween is proportioned for maximum efficiency.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.-

Referring to said drawing,

Figure l is a side elevational view of a material separator provided with the louver of the present invention.

Figure 2 is an enlarged elevational view of the louver construction.

Figure 3 is a top plan view of the construction shown in Figure 2. V

Figure 4 is an end view of several of the louver vanes, taken substantially in the plane indicated by line 44 of Figure 3, but with the vanes disposed in parallel relationship rather than radial relationship for purpose of clarity in the drawing and a better understanding of the details of construction.

The louver of the present invention may be defined as being of an open section type in which unobstructed vertical passages are provided between the adjacent louver 'vanes as distinguished from a closed section type in which there is a lateral overlapping of the vanes. The latter type of construction is shown in the above mentioned patents as well as in my copending application Serial No. 508,031, filed May 13, 1955.

In describing the louver of this invention, it is first deemed advisable to set forth an environment for the same. As best shown in Figure 1 of the drawing, a separator, generally indicated by the numeral 6, is provided and includes a tangential inlet 7, downwardly sloping conically formed side walls 8, and a lower axially aligned discharge opening 9. Material is introduced tangentially into the inlet 7 though a conduit 12 connected to a blower or threshing fan 13. Thus, the fan 13 will direct a flow of fluid and entrained material into the separator 6 whence it is acted upon by centrifugal force and gravital forces to cause a descension of the entrained material of both lighter and heavier unit mass weights. The heavier unit mass weights are adapted to be discharged through the opening 9 while the lighter components of the entrained material are adapted to be removed through an axially extending suction duct 16 connected to a suitable suction fan 17. This general type of construction is not new in the art, as the same may be found in the above mentioned patents, and it is not believed necessary to go into detail as to any further details of construction or mode of operation. 7

As will be understood, the entrained material in the carrier fluid will, by virtue of the centrifugal force, substantially engage and move along the inner peripheral surface of the side walls 8 as it gravitally descends towards the discharge opening 9. If the discharge opening was completely open, it will be appreciated that many particles of even lighter unit mass weight would not be drawn under the influence of the suction duct 16 and therefore would fall downwardly with the particles of heavier unit mass weight. To avoid such a condition, the louver construction 21 is positioned adjacent the discharge 9 for assisting only the heavier particles to descend downwardly and be discharged from-the separa- 3 tor and eflecting a vertical rising of the lighter particles for action by the suction blower 17 and the duct 16.

Referring to Figures 2 through 4 of the drawing, the louver construction will be seen to include an imperforate central baflle portion 22 having a generally shallow frusto-conical body 23, and as best seen in Figure 3,

portion 22 extends across and covers more than onehalf the cross sectional area of the housing at the louver location. The flatness of the body is illustrated by the fact that the maximum diameter of body 23 is substantially greater than the vertical height or rise of the body at the central portion thereof. In practice, the diameter is preferably at least twice as great as such height. The axis of the louver as well as of the imperforate conical portion is aligned with the outlet 9 and the axis of the suction duct 16. While it might be considered that having an imperforate central portion would minimize the volume to be handled by the apparatus, it will be recalled that the entrained material is cast against the side walls 8 by virtue of the centrifugal force and hence the central portion of the separator chamber is substantially free from any particles of either lesser or greater unit mass weights. With an absolutely flat horizontal division plate, it has been found that there is some tendency for heavier materials to move axially inwardly and be influenced by the suction duct. However, the flat frustoconical configuration of the member 22 seems to aid in guiding the lighter materials to move inwardly and upwardly towards the axis of the separator and thereby pass under the influence of the suction duct 16, while inhibiting the denser materials from so doing.

Disposed within an annular space 26 defined between the periphery of baflle portion 22 and side wall 8 are a plurality of vanes 27 which extend on their longitudinal axis generally radially from the axis of the conical member 22. In cross section, taken substantially normal to the radial extent of the vanes, as best illustrated in Figure 4, each of the vanes 27 is spaced from its immediate adjacent vane and the vanes are of generally arcuate cross sectional configuration. Also, as the bottom of the separator as Well as the louver construction tapers downwardly, the outermost edges 29 of the vanes are disposed immediately adjacent the side wall of the separator and therefore must likewise taper inwardly and downwardly.

Referring again to Figure 4 it will be seen that each vane has a generally flat radially extending horizontal upper portion 31, which is preferably slightly olfset in the neighborhood of degrees from the horizontal and terminating in a radially extending distal edge 34 As the vane continues down into its more vertical lower portion 32 it will be seen that such lower portion is tipped forwardly from what might be termed a vertical plane in the amount of approximately degrees. Insofar as its relationship with an adjacent vane, it has been found desirable to have approximately two-thirds of the annular space 26 covered with vanes and approximately one-third of the area being open. In other words, the circumferential width B of a vane is approximately twice the width of space A existing between the leading edge of one vane and the rearmost intermediate arcuate portion 35? of an adjacent vane; and the vane width B is substantially equal to the vertical extent of the vane. This type of construction is clearly distinguishable from an overlapping type of vane relationship, and permits large volumes of material to be handled without danger of clogging or matting of material between closely displaced vanes.

Naturally, the position of the vanes is related to the direction of air or other fluid movement in the separator, as is illustrated in Figure 4. That is, the entrained material in the carrier fluid, upon descending onto the respective vanes, will strike against the generally flat and upwardly sloping vane portion 31, resulting in the lighter components moving upwardly along the imperforate central conical portion 23, and permitting the heavier components to gravitally descend between adjacent vanes as their momentum is diminished. Also, it will be understood that the influence of duct 16 results in air being drawn upwardly through the vanes, and due to the positioning thereof, such air will be drawn into the separator chamber in general conformity with the existing fluid flow therein.

While the foregoing construction may have operational limitations in separating materials having relatively low unit mass weight differentials, it is extremely efiicientin separating materials of greater ratios of different unit mass weights, and has proven successful for such type of operations. Once again, it must be admitted that at the present time the exact phenomena of material action is not completely understood, but it is believed that the area immediately adjacent the concave intermediate portion of the vanes provides a substantially dead air space and a layer of air immediately adjacent thereto provides the suction pattern. In any event, the apparatus is satisfactory and performs more efiiciently than louver constructions heretofore available in separating equipment.

What is claimed is:

LSeparating apparatus of the dry cyclone type in-. cluding a separating chamber having a lower discharge opening, a louver having a central imperforate portion disposed adjacent said opening and including a plurality of vanes, each of said vanes extending from the outer periphery of said portion radially outwardly to adjacent the side walls of said separator, the cross-sectional shape of said vanes being arcuate with the uppermost radially extending edge of each vane being substantially circumrferentially spaced from the rearmost and lowermost edge portion of an adjacent vane so as to define an unobstructed vertical passage between adjacent vanes.

2. Apparatus as Set forth in claim 1 in which the spacing between adjacent vanes is approximately one-half the circumferential width of each vane.

3. A louver for use with a material separator of the dry cyclone type comprising an imperforate central member, a plurality of vanes having the length thereof extending radially outwardly from said imperforate member, the cross-sectional shape of each of said vanes including a generally flat horizontal upper portion having a radially extending distal edge and a generally fiat vertical lower portion having a radially extending distal edge, and an intermediate arcuate portion interconnecting said upper and lower portions, said upper portion sloping upwardly from a horizontal plane towards the distal edge thereof and the edge of said lower portion sloping inwardly from a vertical plane in the direction of said upper portion distal edge.

4. Apparatus as set forth in claim 3 in which said upper portion is sloped approximately 5 degrees from a horizontal plane and said vertical portion is sloped approximately 10 degrees from a vertical plane.

5. Apparatus of the character described comprising a substantially imperforate horizontally disposed bafiie member having a circular periphery, a plurality of circumferentially spaced vanes secured to said baflle member and extending radially outward from the periphery thereof, each of said vanes in cross-section having a substantially flat upper portion terminating in a radially extending upper edge, an intermediate portion of arcuate form. and a downwardly directed lower portion terminating in a radially extending lower edge, the upper edge of each of said upper vane portions being circumferentially spaced from the lower edge of an adjacent vane so as to provide clear vertical openings therebetween.

6. In separating apparatus having a housing provided with a tangential inlet at the upper end thereof, a central discharge opening at the lower end thereof, and an axially aligned suction duct having a lower throat opening disposed in axially spaced relation to and above said discharge opening; a louver extending horizontally across said housing intermediate said throat and opening, said louver having a substantially imperforate central portion axially aligned with said throat and opening and covering more than one-half the cross-sectional area of said housing at the louver location, a plurality of circumferentially spaced vanes mounted on said central portion and extending radially outwardly therefrom, each of said vanes having a width transverse to the radial extent thereof substantially equal to the vertical depth thereof and being laterally spaced from adjacent vanes so as to provide unobstructed vertical passages therebetween, said vanes being substantially straight in a radial direction, and being of arcuate cross-sectional form in a plane normal to the radial extent thereof.

7. Apparatus as set forth in claim 6 in which the central portion of said louver is of inverted shallow frustoconical configuration having a maximum diametrical extent substantially greater than the height thereof.

8. Louver construction for separating apparatus of the dry cyclone type comprising a member including a horizontally disposed imperforate baffle having a circular outer periphery, a plurality of vanes radiating outwardly from said periphery, each of said vanes having a crosssectional form comprising a substantially horizontal upper portion and a substantially vertical portion depending therefrom, the radially extending distal edge of each of said upper portions being circumferentially spaced from the vertical portion of an adjacent vane so as to provide an unobstructed vertical passage between adjacent vanes, and the circumferential width of each vane being substantially twice the width of said passage.

9. Apparatus as set forth in claim 8 in which said bafiie is of shallow inverted frusto-conical form having a diameter at least twice as great as the axial height thereof and with the area covered .by said bafiie being substantially twice as great as the cross-sectional area of said member.

10. Apparatus as set forth in claim 8 in which the upper portion of each vane is ofiset from a horizontal plane and slopes upwardly towards said distal edge thereof, and in which said vertical portion is ofiset from a vertical plane and slopes inwardly relative to said upper portion, whereby said upper and vertical portions define an acute angle therebetween.

11. A louver construction of the character described comprising a horizontally disposed central member having a generally circular plan configuration and a plurality of circumferentially spaced vanes extending radially outwardly from said member, each of said vanes having a cross-sectional shape comprising a substantially horizontal upper portion having a radially extending distal edge and a substantially vertical lower portion having a radially extending distal edge depending from said upper portion, with the upper edge of the respective vanes being circumferentially spaced from the lower edge of its adjacent vane so as to provide an unobstructed vertical passage between adjacent vanes, the circumferential width of each of said vanes being substantially equal to the vertical depth thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,638,181 Gordon May 12, 1953 2,638,218 Simpson et a1 May 12, 1953 2,638,219 Gordon et a1. May 12, 1953