AU2021221453A1

AU2021221453A1 - Dust suppression

Info

Publication number: AU2021221453A1
Application number: AU2021221453A
Authority: AU
Inventors: Scott Pate
Original assignee: Pate Scott Robert
Current assignee: Pate Scott Robert
Priority date: 2021-08-24
Filing date: 2021-08-24
Publication date: 2023-03-16

Abstract

(Figure 2) A dust cover is applied to a mixing process. The dust cover has a top plate 11, an air outlet elbow 12 and an inet 13 with a pivoting valve plate 14. The valve plate 14 has an inner door section 15 and is biassed upward by counter weight plate section 16. The valve pivots about pivot pin 17 journaled in holes 18,19 in side walls 20 and 21 of chute section 22. The chute section has a front wall 23 and is open toward plate 16 to prove a lead in for a bag holding cement powder or the like The cover plate 11 has a central hole 24 for a mixing shaft of a mixer. Diametrically opposed slots 25, 26 receive locating tabs 27, 28 on a mixing drum 29. The cover plate is a loose fit. A vacuum is provided by a venturi assembly 50 fitted to the elbow 12. Air supply to the venturi neck 51 is via inlet 52 along pipe 53 and may be drawn off the air supply to the pneumatic motor 54. Air and fine particles entrained therein are drawn under the cover and off through the venturi where they are wetted down to be separated from the air stream using a spray nozzle at 55 downstream of the venturi so that a liquid is generated along outlet pipe 56. cI qb

Description

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DUST SUPPRESSION TECHNICAL FIELD

[0001] THIS INVENTION relates to dust suppression and in particular but not limited to a portable dust suppression system involving a loose fitted cover for a mixer of the type using a powder mixed with water, sand or aggregate for concrete, grout, mortar or the like.

BACKGROUND

[0002] Dust is problematic in many situations. One circumstance involved is closed environments such as indoors including sheds, also in underground mines or any space where air quality may be compromised by the process involved. While indoors or underground are cases in point, even outdoors situations may arise where dust is still hazardous to personnel who may be inadvertently exposed before the dust disperses.

[0003] In general the present invention has application wherever there is a localised source of dust during some form of procedure and a vacuum may be applied to remove the dust.

[0004] The dust may be generated at the source of a process as in a grinding, cutting, sanding, mixing or may be as a result of adding particulates to a process as in mixing including cement powder or even for that matter production as may be the case with flour and bread making. The principles of the present invention may apply in many and verified applications.

[0005] Generally, the present invention involves some form of containment, shroud, bowl or drum where a process is taking place or has taken place usually below or inside the containment. Problems may arise introducing ingredients or by reason of accumulation and leakage.

[0006] Processing typically involves one or more operators who may be exposed to airborne particulates of various concentrations, the process may result in higher than permitted concentrations in a closed space during or after the process is completed. This may adversely affect persons passing through the space.

OUTLINE

[0007] In one aspect particulates generated during a generally contained process are drawn off using a system with vacuum preferably provided by a venturi and a cover, which provides for drawing into the system any particulates that would otherwise escape the contained process. The system may be provided by purpose built inlets or by a cover being loosely fitted to a containment.

[0008] Thus a venturi is fitted downstream of the containment and may be fitted to the cover. This system is portable where the cover is separate from the containment which may be a housing shroud or bowl or drum or similar.

[0009] Naturally, all that is required is the cover and air supply to the venturi. Ingredients for the process may be added via ports of tubes which may be through the cover. Implements used in the process may also pass through the cover.

[0010] In some cases a portable mixer is employed In some cases water is employed as in a mixing process and in these cases some water may be diverted to a position downstream of the venturi, this water may be sprayed and added to an output to form a slurry so that the particulates may be separated from the air. In other cases other forms of separation may be used includings small cyclonic separators or the like.

[0011] In the case of particles being added to the containment to support a process as in for example a mixing process, it is preferable to provide an inlet that inhibits or minimises dust generation. In the case of manual entry and in for example, bags of mortar or cement powder, an automatic chute, valve or other non-return is provided so that an operator may minimise that amount of airborne particles generated as the bag is being placed into the chute. This may involve a door biased to a closed position. Where possible this may be a gravity bias. In one example a pivot door with an overbalance to a closed door. The door may include a lead in or entrance tray section to aid bag alignment and positioning.

[0012] Thus, in a preferred example there is provided a cover for a mixing drum, the cover having at least one inlet for ingredients used in the drum, the at least one inlet being for dry particulate ingredients, the cover further having air outlet, there being a source of vacuum connected to the outlet, typically the source of vacuum is provided by a venturi connected downstream of the air outlet. Preferably the drum has cover locating means and the cover is a loose fit on the drum. Preferably the cover has a mixer opening in the cover for a mixer. The mixer may be a pneumatic mixer that shares a common source of air with the venturi. Preferably, downstream of the venturi is a water spray nozzle to apply water to the air and particles entrained therein.

[0013] While the system is operative in combination with the process it will be appreciated that the dust cover may be supplied and the other components fitted to it. Thus, in a further aspect the invention comprises a dust cover suitable for use. Thus in one preferred form there is provided a dust cover, which adapts a mixer in a mixing process, the dust cover has a top plate, an air outlet and a particulate inlet with a normally closed door, the cover plate has a mixer entry hole for a mixing shaft of a mixer and the cover being adapted to fit over a mixing drum, a venturi assembly fitted to the air outlet and a spray nozzle downstream of the venturi so that a liquid is generated along an outlet pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order that the present improvements maybe more readily understood and put into practical effect reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein:

Figure 1 is a top view of part of a dust suppression system, in this application, a dust cover; Figure 2 is a drawing showing an arrangement where the system being employed with bagged particulates being dispersed into a mixer; and Figure 3 is a part section through 3-3 of the arrangement of Figure 2.

METHODOFPERFORMANCE

[0015] Referring to the drawings there is illustrated in Figure 1 a dust cover, which effectively adapts the system to a particular use. In this example it is applied to a mixing process. The dust cover has a top plate 11, an air outlet elbow 12 and an inet 13 with a pivoting valve plate 14. The valve plate 14 has an inner door section 15 which is shown closed. This is biassed upward by counter weight plate section 16. The valve pivots about pivot pin 17 journaled in holes 18,19 in side walls 20 and 21 of chute section 22. The chute section has a front wall 23 and is open toward plate 16 to prove a lead in for a bag holding cement powder or the like (see Figure 2). The cover plate 11 has a central hole 24 for a mixing shaft of a mixer. Diametrically opposed slots 25, 26 receive locating tabs 27, 28 on a mixing drum 29. The cover plate is a loose fit.

[0016] An pneumatic mixer assembly 30 is located on a diametrically positioned plate 31. This has slots 32, 33 so that this may also be located over tabs 27, 28. The mixer shaft 34 extends to a helical blade mixer 35 in the bottom of drum 29. A pipe 36 extends down the drum to an opening 37 to hold a downpipe 38 of a slurry pump assembly 39 to pump mixed mortar, cement mix or the like out of the drum along line 40. The mixed slurry is at 41 where particulate 43 is mixed with water. As shown in Figure 2, particulate 43 is poured by a user 44 from a bag 45 into chute 22 through opening 46 caused by the operator locating the bag as shown while lifting plate section 16 to open the inlet. This creates dust inevitably, with some clouding about the chute walls, the bag may also be damaged creating more leakage, so the cover being loose fitted this leakage may be captured. The operation of a vacuum via elbow 12 may draw dust under the cover, see arrows 47, 48 and 49 which schematically illustrate this external flow into the drum.

[0017] In this case a vacuum is provided by a venturi assembly 50 fitted to the elbow 12. Air supply to the venturi neck 51 is via inlet 52 along pipe 53 and may be drawn off the air supply to the pneumatic motor 54. Air and fine particles entrained therein are drawn under the cover and off through the venturi where they are wetted down to be separated from the air stream. In this case there is full cone spray nozzle at 55 downstream of the venturi so that a liquid is generated along outlet pipe 56.

[0018] Other features of the Figures include air valve control lever 57, air line 58, hose fittings 60, water line 61. Water may be introduced to the drum 29 through opening 46 or pipe 36.

[0019] Whilst the above has been given byway of illustrative example many variations and modifications will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims.

Claims

1. A system where particulates generated during a generally contained process are drawn off using the system with vacuum provided and a cover, which provides for drawing into the system any particulates that would otherwise escape the contained process.

2. A system according to claim 1 having a venturi is fitted downstream of the containment and fitted to the cover.

3. A system according to claim 1 which is portable where the cover is separate of but removably fitted to the containment, the containment being a housing, shroud, bowl, drum or similar.

4. A system according to any one of the preceding claims wherein ingredients for the process may be added via ports or tubes which may be through the cover and implements used in the process also pass through the cover.

5. A system according to any one of the preceding claims where a portable mixer is employed.

6. A system according to any one of the preceding claims where water is added to an output to form a slurry so that the particulates may be separated from the air.

7. A system according to any one of the preceding claims in the case of particles being added to the containment to support a mixing process, there is an inlet for the particles that inhibits or minimises dust generation.

8. A system according to any one of the preceding claims in the case of manual entry the system includes an automatic chute, valve or other non-return so that an operator may minimise that amount of airborne particles generated as particulates are being placed into the chute.

9. A system according to any one of the preceding claims having an inlet as a door biased to a closed position.

10. A system according to any one of the preceding claims, the cover having a gravity biassed normally closed door.

11. A system according to any one of the preceding claims, the cover having a door which includes a lead in or entrance tray section to aid bag alignment and positioning.

12. A system according to any one of the preceding claims comprising a cover for a mixing drum, the cover having at least one inlet for ingredients used in the drum, the at least one inlet being for dry particulate ingredients, the cover further having air outlet, there being a source of vacuum connected to the outlet, typically the source of vacuum is provided by a venturi connected downstream of the air outlet.

13. A system according to any one of the preceding claims wherein the drum has cover locating means and the cover is a loose fit on the drum.

14. A system according to any one of the preceding claims and the cover has a mixer opening in the cover for a mixer.

15. A dust cover, which adapts a mixer in a mixing process, the dust cover has a top plate, an air outlet and a particulate inlet with a normally closed door, the cover plate has a mixer entry hole for a mixing shaft of a mixer and the cover being adapted to fit over a mixing drum, a venturi assembly fitted to the air outlet.

16. A dust cover according to claim 15 where the normally closed door is adapted for manual loading of particulates from a bag.

17. A dust cover according to claim 15 or claim 16 having a spray nozzle downstream of the venturi so that a liquid is generated along an outlet pipe.

18. A dust cover when used in the system according to any one of claims 1-14.