Rock duster apparatus

• US 4,538,941 A
• Filed: 07/25/1983
• Issued: 09/03/1985
• Est. Priority Date: 07/25/1983
• Status: Expired due to Fees

• Current Assignee: National Mine Service Co.
• Original Assignee: National Mine Service Co.
• Inventors: Thorne, Gary H.
• Primary Examiner(s): Nase, Jeffrey V.
• Application Number:
  US06/517,062
• Time in Patent Office: 771 Days
• Field of Search: 406/118, 406/143, 406/144, 406/153, 51/436, 239/310, 239/318, 239/654, 239/655
• US Class Current: 406/143
• CPC Class Codes: B65G 53/42 Nozzles

Abstract

A venturi section positioned in the flow path of pressurized air through a rock dust hopper includes an opening connected to a conduit extending to the axis of the venturi section. Concentric conduits within the venturi section direct the stream of pressurized air directly into intersecting relation with the conduit. The flow of pressurized air immediately below the conduit creates a reduced pressure to induce a continuous flow of rock dust through the venturi section opening and into mixture with the air stream which carries the entrained rock dust from the venturi section for discharge from a nozzle outlet.

Claims

1. Rock duster apparatus comprising,

a support frame having an upper surface,

a hopper for storing rock dust positioned on said support frame upper surface,

said hopper having an inlet opening and an outlet opening, said inlet and outlet openings being oppositely positioned,

means for supplying a preselected flow of pressurized air to said hopper,

control means for controlling the means for supplying a preselected flow of air,

conduit means extending from said control means through said hopper inlet opening for directing pressurized air from said control means into said hopper,

a first conduit positioned in said hopper and having an outlet end extending through said hopper outlet opening and an inlet end positioned adjacent said conduit means in said hopper,

said first conduit having a passageway extending between said inlet and outlet ends,

said first conduit having an opening positioned between said inlet and outlet ends,

a second conduit positioned in said first conduit opening and extending upwardly into said first conduit passageway,

said second conduit having an inlet end and an outlet end, said outlet end being positioned in said first conduit passageway,

a third conduit positioned in said first conduit passageway and extending through said first conduit inlet end to said second conduit,

means for supporting said third conduit coaxially in said first conduit passageway,

said third conduit having an inlet end connected to said conduit means and an outlet end,

said third conduit outlet end being postioned at an angle with respect to the axis of said first conduit passageway in the direction of flow of the pressurized air through said third conduit,

said third conduit having a passageway threrethrough, and

said third conduit outlet end abutting said second conduit at a contact point a preselected distance above said second conduit outlet end such that the flow of pressurized air through said third conduit past said second conduit outlet end creates a reduced pressure in said second conduit for continuously drawing rock dust from said hopper through said second conduit and into said first conduit for mixture with pressurized air out of said hopper outlet opening.

2. Rock duster apparatus as set forth in claim 1 in which,

said first conduit opening is positioned at a preselected angle with respect to a horizontal plane extending through the longitudinal axis of said first conduit.

3. Rock duster apparatus as set forth in claim 1 in which,

said third conduit abuts said second conduit at said contact point and is positioned perpendicular to said second conduit.

4. Rock duster apparatus as set forth in claim 3 in which,

said second conduit outlet end is positioned in the path of the pressurized air flowing from said third conduit outlet end.

5. Rock duster apparatus as set forth in claim 1 in which,

said third conduit outlet end is positioned at an angle of 45°

with respect to the axis of said first conduit passageway and extends into abutting relation with said conduit at said contact point.

6. Rock duster apparatus as set forth in claim 1 in which,

said means for supporting said third conduit coaxially in said first conduit passageway maintains the axis of said third conduit aligned with said outlet end of said second conduit.

7. Rock duster apparatus as set forth in claim 1 in which,

said means for supporting said third conduit coaxially in said first conduit passageway includes a pair of bushings positioned in surrounding relation with said third conduit,

one of said bushings being secured in said first conduit inlet end and secured in surrounding relation to said third conduit, and

the other of said bushings being secured in said first conduit passageway and secured in surrounding relation to said third conduit adjacent said outlet end thereof.

8. Apparatus for entraining particulate material in a stream of air comprising,

a first conduit having an inlet end and an outlet end with a passageway therethrough for directing a stream of air from said inlet end to said outlet end,

said first conduit having an opening into said passageway between said inlet and outlet ends,

a second conduit positioned in said first conduit opening and extending upwardly into said first conduit passageway,

a third conduit positioned in said first conduit passageway and extending through said first conduit inlet end to said second conduit,

means for supporting said third conduit coaxially in said first conduit passageway,

said third conduit having an inlet end for receiving a stream of air and a passageway therethrough, and

said third conduit having an outlet end abutting said second conduit at a contact point a preselected distance above said second conduit outlet end such that the flow of air through said third conduit and past said second conduit outlet induces a reduced pressure in said second conduit for continuously drawing particulate material into said first conduit opening and through said second conduit and into said first conduit for mixture with the stream of air and conveyance out of said first conduit outlet end.

9. A method for entraining particulate material in a stream of air comprising the steps of,

supplying a stream of air to an inlet end of a first conduit,

conveying the stream of air along an axial path to a preselected point in the first conduit,

supplying particulate material into the first conduit along a preselected path through a second conduit to a discharge point in the first conduit which is positioned in the axial path of the stream of air in the first conduit,

confining the direction of movement of the particulate material from the second conduit into the first conduit along the preselected path which is perpendicular to the path of the stream of air in the first conduit,

positioning the outlet end of a third conduit in the first conduit at the discharge point of the particulate material into the first conduit so that the flow path of the stream of air from the third conduit is in a direct line with the outlet end of the second conduit,

directing the stream of air at the discharge point to create a reduced pressure at the point where the particulate material is discharged from the second conduit and is applied to the first conduit,

reducing the pressure at the discharge point by the flow of pressurized air from the first conduit past the discharge point through the third conduit to induce a continuous flow of particulate material through the discharge point into the first conduit, and

entraining the flow of particulate material in the stream of air for conveyance out of the first conduit.