Dedusting apparatus having air knives and ionizing wires

Abstract

A dedusting apparatus removes dust and debris from particulate material flowing over the surface of a wash deck formed with steps and incorporating an air knife engaging the flow of particulate material as the material drops from one wash deck level to another. An ionizing wire is placed at each step on the wash deck so that the air knife blows negative ions from the ionizing wire into the particulate material falling off the step onto the level of wash deck below the ionizing wire. The wash deck is formed with openings to allow air to blow through the wash deck surface and remove dust and debris from the flow of particulate material. The wash deck can be constructed from modules supported on one another in a manner to present an overhang at each step. The wash deck can be formed from a flat pattern as a unitary bent structure.

Claims

1. A dedusting apparatus for cleaning dirt and debris from particulate material, comprising: a housing; a product infeed located at an upper portion of said housing for the introduction of particulate material to be cleaned into said housing; a primary wash deck supported in said housing below said product infeed to receive a flow of said particulate material from said product infeed onto said wash deck, said wash deck being formed from a plurality of wash deck modules defining a cleaning portion and a support flange, each said cleaning portion having a plurality of holes therethrough and each said support flange including a plurality of air knife openings; an air inlet opening in said housing to introduce a first air flow beneath said primary wash deck to provide an air flow through said holes in each said cleaning portion and through said air knife openings to accelerate particulate material flow along said primary wash deck; and an ionizing wire positioned along each said support flange in alignment with said air knife openings to provide a source of negative ions to be transferred to said particulate material dropping from one wash deck module to another in front of said support flange.

2. The dedusting apparatus of claim 1 wherein said primary wash deck is formed with an uppermost wash deck module that includes only a cleaning portion supported on the support flange of the next wash deck module.

3. The dedusting apparatus of claim 1 wherein said primary wash deck includes opposing side walls formed with mounting slots therein, each said cleaning portion and each said support flange being formed with a tab on opposing ends thereof for receipt within a corresponding mounting slot in said side walls.

4. The dedusting apparatus of claim 1 wherein said each said support flange supports a cleaning portion of the wash deck module thereabove in an overlapping manner such that the ionizing wire is positioned beneath the supported overlapping cleaning portion and in front of the corresponding support flange.

5. The dedusting apparatus of claim 1 wherein said primary wash deck is oriented at a slope of approximately 15 degrees.

6. The dedusting apparatus of claim 1 wherein said housing further supports a secondary wash deck positioned below said primary wash deck to receive particulate material discharged off of said primary wash deck and direct said particulate material toward a product discharge opening.

7. The dedusting apparatus of claim 6 wherein each said secondary wash deck is formed with secondary wash deck modules having only said air knife openings formed therein to accelerate the flow of particulate material toward said product discharge opening.

8. The dedusting apparatus of claim 7 wherein said housing includes a supplemental air opening below said secondary wash deck to provide a flow of air through said air knife openings in said secondary wash deck modules.

9. The dedusting apparatus of claim 1 wherein said primary wash deck is formed of two wash decks mounted with the uppermost wash deck modules connected at an apex below said product infeed, said primary wash decks being directed downwardly from said apex in opposing directions, said secondary wash deck including a secondary wash deck below each of said primary wash decks to receive respectively particulate material therefrom.

10. The dedusting apparatus of claim 1 wherein said ionizing wire is located behind the air knife openings, with respect to the flow of air through the air knife openings, so that the air flow through the air knife openings carries the negative ions into the flow of particulate material falling in front of said support flanges.

11. In a dedusting apparatus for cleaning particulate material, said dedusting apparatus having a housing; a product infeed located at an upper portion of said housing for the introduction of particulate material to be cleaned into said housing; a wash deck supported in said housing below said product infeed to receive a flow of said particulate material from said product infeed onto said wash deck; and an air inlet opening in said housing to introduce a flow of air beneath said wash deck, the improvement comprising: said wash deck being formed as a unitary formed device bent from a flat pattern into a shape having a plurality of generally vertical steps separated by planar cleaning surfaces with said plurality of cleaning surfaces being located between respective vertical steps, each said cleaning surface having a plurality of cleaning holes formed therein for the passage of air therethrough to pass through said particulate material flowing over said cleaning surfaces, each said vertical step including air knife openings for the passage of air therethrough creating an air knife to engage particulate material falling from an upper cleaning surface to a lower cleaning surface, and an ionizing wire positioned behind each vertical step with respect to the direction of air flow through said air knife openings in alignment with said air knife openings such that the flow of air through said air knife openings carries negative ions through said air knife openings into said particulate material falling in front of the corresponding said vertical step.

12. The dedusting apparatus of claim 11 wherein said wash deck is formed from a plurality of wash deck modules with each module including one of said planar cleaning surfaces and one of said vertical steps extending generally orthogonally to the corresponding said cleaning surface.

13. The dedusting apparatus of claim 12 wherein the cleaning surface of said cleaning surface of an upper wash deck module rests on said vertical step of a lower wash deck module for support thereof.

14. The dedusting apparatus of claim 13 each said wash deck module includes a first mounting tab along opposing edges of said planar cleaning surfaces and a second mounting tab along opposing edges of said vertical step, each said wash deck module being engaged with opposing side walls having mounting openings therein to receive said first and second mounting tabs for support of each said wash deck module.

15. The dedusting apparatus of claim 13 further comprising: an ionizing wire supported along each said vertical step in alignment with said air knife openings so that said air flow through said air knife openings carries negative ions into said particulate material falling from upper wash deck module to said lower wash deck module.

16. The dedusting apparatus of claim 15 wherein each upper cleaning surface resting on the corresponding lower vertical step overlaps the lower vertical step and a portion of the lower cleaning surface to provide an overhang member, said ionizing wire being positioned beneath said overhang structure in alignment with said air knife openings through said lower vertical step.

17. The dedusting apparatus of claim 15 wherein said ionizing wire is positioned behind the corresponding air knife openings with respect to the direction of air flow through said air knife openings such that the flow of air through said air knife openings carries negative ions through said air knife openings into said particulate material falling in front of the corresponding said vertical step.

18. A dedusting apparatus for cleaning dirt and debris from particulate material, comprising: a housing; a product infeed located at an upper portion of said housing for the introduction of particulate material to be cleaned into said housing; a wash deck supported in said housing below said product infeed to receive a flow of said particulate material from said product infeed onto said wash deck, said wash deck being formed as a unitary formed device bent from a flat pattern into a shape having a plurality of generally vertical steps and a plurality of cleaning surfaces between successive vertical steps, each said cleaning portion having a plurality of cleaning holes therethrough and each said vertical step including a plurality of air knife openings; an air inlet opening in said housing to introduce a first air flow beneath said primary wash deck to provide an air flow through said cleaning holes in each said cleaning portion and through said air knife openings to accelerate particulate material flow along said wash deck; and an ionizing wire positioned behind each vertical step with respect to the direction of air flow through said air knife openings, said ionizing wire being in alignment with said air knife openings such that the flow of air through said air knife openings carries negative ions through said air knife openings into said particulate material falling in front of the corresponding said vertical step.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:

(2) FIG. 1 is a front elevational view of a compact dedusting apparatus incorporating the principles of the instant invention;

(3) FIG. 2 is an enlarged side elevational view of a portion of the wash deck shown in FIG. 1 with the ionizing wires mounted beneath an overhang in front of air knife slots formed in the vertical step;

(4) FIG. 3 is a further enlarged side elevational view of a portion of the wash deck showing the holes through the wash deck modules, the air knives, and the ionizing wires incorporating the principles of the instant application;

(5) FIG. 4 is an upper perspective view of a portion of the wash deck to show the holes through the wash deck modules and the air knives;

(6) FIG. 5 is an exploded view of the connection between each wash deck module and the side walls supporting the wash deck module;

(7) FIG. 6 is a top perspective view of a wash deck showing the individual wash deck modules and side walls in phantom with the ionizing wire system being schematically shown in solid lines;

(8) FIG. 7 is an enlarged top view of the connection between the ionizing wire and the electrical supply wires interconnecting the ionizing wires corresponding to circle 7 in FIG. 6;

(9) FIG. 8 is a further enlarged elevational view of the connection between one of the ionizing wires and the electrical supply wires;

(10) FIG. 9 is an enlarged side elevational view of a portion of the wash deck similar to that of FIG. 2, but with the ionizing wires mounted behind the vertical step so that ions are blown through the air knife slots in the vertical step;

(11) FIG. 10 is a further enlarged side elevational view of a portion of the wash deck corresponding to the embodiment depicted in FIG. 9, showing the ionizing wires positioned behind the air knife slots in vertical steps;

(12) FIG. 11 is an enlarged side elevational view of a portion of the wash deck similar to that of FIG. 9, but formed as a unitary bent structure and having the ionizing wires mounted behind the vertical step;

(13) FIG. 12 is a further enlarged side elevational view of a portion of the wash deck corresponding to the embodiment depicted in FIG. 11, showing the ionizing wires positioned behind the air knife slots in vertical steps;

(14) FIG. 13 is a schematic representation of a portion of a flat pattern for creating the integral bent wash deck depicted in FIG. 11, bend lines being depicted as dotted lines; and

(15) FIG. 14 is a schematic elevational view of a portion of the integral, bent wash deck after the flat pattern has been through a manufacturing process to bend the flat pattern along the bend lines.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(16) Referring to FIG. 1, a dedusting apparatus 10 is typically associated with a silo unloading of material into bags, trucks, rail cars or any other container (not shown). For purposes of explanation, particulate product (in this example, plastic pellets plus the usual contaminants associated therewith) is fed into the dedusting apparatus 10 at the product inlet 15 where the particulate material falls onto the upper portion of a wash deck 20. Preferably, the upper portion of the dedusting apparatus 10 includes inlet deflectors 12, which direct the flow of material across the top of the wash deck 20 and into a laminar flow as is known in the art. One skilled in the art will recognize that the inlet deflectors 12 can be manually positioned relative to the wash deck 20 or via automated controllers (not shown).

(17) While FIG. 1 depicts a configuration of a dedusting apparatus 10 that has opposing upper wash decks 20 and opposing lower wash decks 21 that receive particulate material discharged from the respective upper wash decks 20 to be directed to a central product discharge outlet 13, other configurations of dedusting apparatus 10 would be equally receptive to using the instant invention, including dual outlet dedusting apparatus, single offset outlet dedusting apparatus, single wash deck with a discharge outlet aligned with the product inlet opening 15, and others. Such alternative configurations can be found in U.S. Pat. No. 8,931,641, granted on Jan. 13, 2015, to Heinz Schneider; in U.S. Pat. No. 8,833,563, granted on Sep. 16, 2014, to Heinz Schneider and Paul Wagner; and in U.S. Pat. No. 7,621,975, granted on Nov. 24, 2009, to Heinz Schneider and Paul Wagner.

(18) Referring now to FIGS. 2-8, the details of the instant invention can best be seen. The wash deck 20 is formed by a plurality of wash deck modules 25 that are mounted between opposing side walls 22. The respective width of the wash deck 20 can vary from one dedusting apparatus 10 configuration to another, and therefore, FIGS. 4-6 reflect a central portion of the wash deck 20 being broken away for purposes of clarity. Each wash deck module 25, except for the uppermost wash deck module 29, is formed with a generally planar cleaning portion 26 and a support flange 27 bent upwardly at approximately 80-100 degrees relative to the cleaning portion 26 to support the adjacent cleaning portion 26 of the wash deck module 25 thereabove.

(19) Each wash deck module 25 terminates in opposing side edges engaged with the side walls 22 with each cleaning portion 26 having a tab 28 projecting from the side edge of the cleaning portion 26, and each support flange 27 also have a tab 28 projecting outwardly therefrom, so that the tabs 28 on each side of the wash deck 25 can be inserted into openings 23 formed in the side walls 22 to receive the tabs 28. Accordingly, each wash deck module 25 is supported from the opposing side walls 22 from the tabs 28 extending through the openings 23 in the side walls 22. The openings 23 are positioned such that the cleaning portion 26 of each wash deck module 25 rests on top of the support flange 27 of the module immediately below. In addition, the front edge of each wash deck module 25, 29, except for the lowermost wash deck module 25, overlaps the support flange 27 and establishes an overhang of the beginning of the cleaning portion 26 of the wash deck module 25 below.

(20) The cleaning portion 26 of each wash deck module 25, 29 is formed with a plurality of holes 32 extending through the wash deck module 25 for the passage of air therethrough. The holes 32 can be arranged in one or more rows of holes transversely oriented across the cleaning portion 26, depending on the size of the wash deck modules 25 or the holes 32 could be dispersed in a different pattern, so long as the holes 32 provide a cleaning flow of air from beneath the wash deck 25 and through the flow of particulate material flowing over the top of the cleaning surface 26, as will be described in greater detail below.

(21) Each support flange 27 is also formed with a plurality of openings 35 arranged in a row across the transverse width of the support flange 27 to form an air knife 30 flow of air through the support flange 27 and directed into the flow of particulate material falling off the overlapping discharge edge of the cleaning portion 26 of the wash deck module 25 thereabove. This air knife 30 serves to accelerate the flow of particulate material down the wash deck 20, and thus eliminates, or at least minimizes, the need for slots to be formed in the cleaning portion 26 of each wash deck module 25 as is known in prior art dedusting apparatus. In addition, the air knife 30 also serves to remove contaminants from the flow of particulate material falling off the overlapping edge of the cleaning surface 26 thereabove. Further, the air knife 30 also pushes ions from the ionizing wire 42, which will be described in greater detail below, into the flow of particulate material so that the ions will connect with the dust particles in the air and on the surface of the particulate material pellets.

(22) With the air knife 30 accelerating particulate material across the adjacent cleaning surface 26, the slope of the wash deck 25 can be significantly shallower than is known in the existing dedusting apparatus. Conventional wash decks of known dedusting apparatus are typically oriented at approximately 30 degree from horizontal. With the induced acceleration from the air knives 30, the orientation of the wash decks 25 can be reduced to approximately 15 degrees, which enables the structure of the dedusting apparatus to have a smaller height than previously known in the art.

(23) For dedusting apparatus configurations utilizing a lower wash deck 17, as depicted in FIG. 1, the lower wash decks 21 would also be formed from wash deck modules 25, stacked as described above. However, the wash deck modules 25 may not require the formation of any holes 32 through the cleaning portion 26 of each wash deck module 25, as the cleaning operation of the upper wash decks 25 could be sufficient to remove the unwanted contaminants from the flow of particulate material. Nevertheless, the support flanges 27 would be formed with openings 35 to form air knives 20 at the beginning of each wash deck module 25 to continue the acceleration of the flow of the cleaned particulate material along the lower wash decks 21 toward the discharge opening 13. This intense flow of air through the air knife openings 35 is also effective in removing contaminants, including streamers, from the particulate material product flow falling off of the overlapping cleaning portion 26 of the wash deck module 25 above the air knife 30.

(24) Each ionizing wire 42 is part of an ionization system 40 forming an integral part of the instant invention to use high voltage electrical current to ionize (electrically charge) air molecules with negative ions that confer a negative charge to particles. As can be seen in the schematic depiction of the ionizing system 40 shown in FIG. 6, the ionizing wire 42 extends from a metal ball 45 allowing the ionizing wire 42 to be pulled taut across in front of each air knife 30. Each ionizing wire 42 receive electrical current from an electrical supply wire 41, which in turn receives electrical current from a power source 49 preferably supported on the rear side of the dedusting apparatus 10. Each metal ball 45 is supported in a non-conductive plastic housing 44 that is part of the plastic cover 43 extending over the supply wires 41, as is schematically shown in FIG. 6.

(25) A preferred embodiment of the ionization system 40 would have the supply wires 41 running along the exterior of the side walls 22 in a non-conductive manner, such as being housed within the plastic cover 43, with a supply wire 41a extending beneath the top edge of the uppermost wash deck module 29 to deliver electric current to the opposing supply wire 41 on the exterior of the opposing side wall 22, completing an electrical circuit. Each ionizing wire 42 is positioned in alignment with the openings 35, preferably in front of the openings 35 as is depicted in FIGS. 2 and 3, but the ionizing wire 42 could also be placed behind the openings 35, as is depicted in FIGS. 9 and 10, so that the air knife 30 formed thereby blows ions from the ionizing wire 42 through the openings 35 and into the flow of particulate material.

(26) Referring now to FIGS. 11-14, one skilled in the art will recognize that the stepped wash deck configuration can be affected by constructing the wash deck 50 as a unitary bent apparatus, rather than constructing the wash deck 20, 50 from modules 25. As is schematically represented in FIGS. 13 and 14, the formed wash deck 50 would start with a flat blank of metal, such as stainless steel, into which the openings 32 and 35 are punched while the flat pattern 52 remains planar. Then the flat pattern 52 can be bent using conventional manufacturing methods along the bend lines 54 to create the formed wash deck 50, as shown in FIG. 14, which orients the air knife openings 35 in the vertical steps and the cleaning openings 32 in the orthogonal planar cleaning portions. Since the formed wash deck 50 is created from a flat pattern 54, the overhang of the cleaning portion 56 over the vertical step 57 and the upper part of the next cleaning portion 56 is eliminated. As a result, the ionizing wire 42 would need to be placed behind the air knife openings 35, with respect to the flow of air therethrough, so that the was deck 50 would protect the ionizing wires 42.

(27) In operation, the dedusting apparatus 10 receives a supply of air under pressure into the housing 11 in a conventional manner, and delivers the air through a central opening 16 located in the back wall of the housing 11 underneath the wash decks 20, and simultaneously through supplemental openings 17 beneath the lower wash decks 21. Air entering through the central opening 16 passes through the holes 32 and openings 35 in the upper wash deck modules 25 to remove contaminants from the flow of particulate material and to distribute ions to the particulate material and to accelerate the particulate material, as is described in greater detail above. The air exiting the upper wash decks 25 ultimately exits the housing 11 through the raised air outlets 19 at the top of the housing 11 on opposing sides of the product inlet 15.

(28) The air entering the housing 11 through the supplemental openings 17 beneath the lower wash decks 21 pass through the air knives 30, and any cleaning holes 32 therein, formed in the respective lower wash deck modules 25 and move through Venturi zones 18 to remove any remaining difficult contaminants from the flow of particulate material dropping off the lowermost wash deck module 25. The air flow through the Venturi zones 18, along with the air flow through the upper wash decks 20 and the contaminants removed from the particulate material discharge through the raised air outlets 19, described above. The air discharged from the housing 11 can be cleaned and recycled and returned to the housing 11, as described above.

(29) One of ordinary skill in the art will recognize that the housing 11 preferably carries a positionally adjustable vertical baffle 14 along each Venturi zone 18 to regulate the air passing through the Venturi zones 18. Bypass boxes 14a are also provided along the sides of the housing 11 behind the vertical baffles 14 to supplement the flow of air through the Venturi zones 18, as needed. This air flow from the bypass boxes 14a flows beneath the vertical baffles 14 and then upwardly through the Venturi zones 18 for a thorough cleaning of the particulate material dropping off the upper wash decks 20 toward the lower wash decks 21. The positioning of the vertical baffles 14 and the adjustment of the amount of air flowing through the bypass boxes 14a provides a large range of control over the operation of the Venturi zones 18. Ultimately, the cleaned particulate material is discharged from the housing 11 through the product discharge port 13, which, depending on the configuration of the housing 11, can be located at the central part of the housing 11 or offset to one or more sides of the housing 11.

(30) Referring to FIGS. 1-8, the air flowing through the central opening 16 exits through the upper wash decks 20 through the holes 32 in the cleaning portions 26 of the wash deck modules 25 to lift and flow through the particulate material top remove contaminants from the particulate material, and also through the air knife openings 35 formed in the support flanges 27 so that the air flow moves past the ionizing wires 42 to transfer ions to the particulate material and the contaminants therein, and to flow through the particulate material dropping off the overlapping edge of one wash deck module 25 onto the next wash deck module 25. In addition, the air moving through the air knife openings 35 also pushes the particulate material downstream and accelerates the flow of the particulate material.

(31) As a result, the upper wash decks 20 do not require the formation of slots in the cleaning portions 26, as is known in the art, to urge movement of the particulate material downstream. Furthermore, the transfer of ions from the ionizing wire 42 eliminates the need to provide an electro-magnetic field to the infeed of particulate material onto the wash decks 20. Also, with the acceleration of the particulate material provided by the air knives 30, the slope of the wash decks 20, 21 can be reduced to about half of the slope of known wash decks of dedusting apparatus, allowing the height of the dedusting apparatus 10 to be reduced significantly without affecting operational efficiencies.

(32) It will be understood that changes in the details, materials, steps and arrangements of parts, which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles of the scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly, as well as in the specific form shown.

(33) For example, while the drawings, specifically FIG. 1, depict a dedusting apparatus 10 having opposing primary and secondary wash decks 20, 21, the principles of the instant invention can be applied to any dedusting apparatus configuration, such as a dedusting apparatus having only a single primary wash deck 20, or a single primary and secondary wash deck 20, 21. Furthermore, the principles of the instant invention can also be applied to the formation of a wash deck for a cylindrical dedusting apparatus, as is disclosed in U.S. Pat. No. 8,800,777, or a half round dedusting apparatus, such as is disclosed in U.S. Pat. No. 10,646,902, by forming a series of steps around the circular circumference of the wash deck and then placing an ionizing wire inside or outside of air knife openings formed in the steps similar to that disclosed above.