GB2040657A - Stoneduster - Google Patents

Abstract

For stonedusting, a stoneduster 10 is supplied with compressed air by a blower 12 which is driven in any convenient manner. The stoneduster itself may be a conventional guniting machine. <IMAGE>

Description

SPECIFICATION Stoneduster This invention relates to stonedusting.

In coilieries and particularly in those underground areas where coal is mined, coal dust which rises into the air during the mining and transporting of the coal settles on the side walls, foot walls, roads and other surfaces. Although the coal dust per se is not dangerous it can become highly explosive when mixed in the correct proportions with the atmosphere and such mixing may occur unavoidably for example during blasting operations which disturb the settled coal dust and cause it to rise into the air.

This danger is recognised in the Mines and Works Act and Regulations and one section thereof deals with the requirements regarding stonedusting in collieries. "Stonedusting" involves the placing of an inert fine particulate material on the surfaces on which the coal dust settles. Generally use is made of limestone dust and the practical effect of stonedusting is to dilute the concentration of the coal dust, thereby preventing any coal dust/air mixtures which may arise from reaching explosive ratios.

It is an object of the present invention to provide apparatus which is relatively inexpensive and robust for use in underground stonedusting applications.

The invention provides stonedusting apparatus which comprises an air powered stoneduster and a source of compressed air arranged to feed air to the stoneduster.

The source of compressed air may be a compressor or a blower which expells air at a pressure and velocity suitable for the operation of the stone duster. For example, the compressed air source may be a blower driven by a prime mover via a transmission unit, which may be an axle and gears, a belt and pulleys, or a hydraulic pump and motor. Any suitable drive may be used to drive the hydraulic pump. For example, the pump may include means whereby it can be coupled to a power takeoff point of an engine, for example, the PTO shaft of a tractor. Or alternatively, the drive for the hydraulic pump, or even directly for the blower itself, may be any suitable form of motor, for example, a diesel internal combustion engine or an electrically powered motor.

The invention also provides a method of stonedusting, wherein a guniting machine is used to discharge the inert particulate material.

Any suitable stoneduster may be used in the apparatus of the invention, but a preferred stone duster is provided by a guniting machine sold under the name "Springbok Rotary Guniter" and manufactured by Turner-Morris (Pty) Limited of Johannesburg.

The invention is further described by way of example, with reference to the accompanying drawing which depicts in block diagram form stonedusting apparatus according to the invention.

The drawing illustrates in block diagram form a stoneduster 10, an air blower 12, a hydraulic motor 14, a hydraulic pump 16 and an engine 18.

The stoneduster 10 in this example of the invention is a guniting machine which is manufactured by Turner-Morris (Pty) Limited of Johannesburg and sold under the name "Springbok Rotary Guniter". It includes an inlet nozzle 20 which is connected to the compressed air outlet nozzle of the blower 12, and a feeding nozzle 22 through which limestone dust or any other suitable inert material is supplied to the stoneduster.

The blower 12 is powered by means of the hydraulic motor 14 which in turn is powered by hydraulic fluid pressurised by the hydraulic pump 16. The hydraulic pump in turn is connected to the engine 18. The engine may for example be the engine of a tractor in which event the hydraulic pump may conveniently be coupled to the PTO shaft of the tractor.

The use of a tractor enables the unit to be transported and also provides power for the blower 12.

In place of the hydraulic transmission via a pump 16 and motor 14 as shown, the blower may be connected via a gear system to the power takeoff shaft of a tractor. Alternately, a separate motor such as an electrically powered motor or a diesel motor may drive the blower directly. A self-powered compressor could also be used.

The stoneduster 10 is used in a conventional way and the inert material supplied to it through the nozzle 22 is blown out through an exit nozzle 24 under the action of the compressed air. The particular utility and benefit of the invention lies in the fact that use may be made of an engine 18 which normally is used for other purposes. The engine is therefore not dedicated to the blower 12 and consequently the stonedusting apparatus can be implemented at a comparatively low cost. The use of an hydraulic interface between the engine and the blower provides an inexpensive and robust means of controlling the operation of the stoneduster.

1. Stonedusting apparatus which comprises an air powered stoneduster and a source of compressed air arranged to feed air to the stoneduster.

2. Apparatus as claimed in Claim 1, wherein the source of compressed air is a blower.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein the stoneduster is a guniting machine.

4. Apparatus as claimed in any preceding claim mounted on a tractor.

5. Apparatus as claimed in Claim 4, wherein the source of compressed air is driven by a power takeoff shaft of the tractor.

6. A method of stonedusting, wherein a guniting machine is used to discharge the inert particulate material.

7. Stonedusting apparatus substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Stoneduster This invention relates to stonedusting. In coilieries and particularly in those underground areas where coal is mined, coal dust which rises into the air during the mining and transporting of the coal settles on the side walls, foot walls, roads and other surfaces. Although the coal dust per se is not dangerous it can become highly explosive when mixed in the correct proportions with the atmosphere and such mixing may occur unavoidably for example during blasting operations which disturb the settled coal dust and cause it to rise into the air. This danger is recognised in the Mines and Works Act and Regulations and one section thereof deals with the requirements regarding stonedusting in collieries. "Stonedusting" involves the placing of an inert fine particulate material on the surfaces on which the coal dust settles. Generally use is made of limestone dust and the practical effect of stonedusting is to dilute the concentration of the coal dust, thereby preventing any coal dust/air mixtures which may arise from reaching explosive ratios. It is an object of the present invention to provide apparatus which is relatively inexpensive and robust for use in underground stonedusting applications. The invention provides stonedusting apparatus which comprises an air powered stoneduster and a source of compressed air arranged to feed air to the stoneduster. The source of compressed air may be a compressor or a blower which expells air at a pressure and velocity suitable for the operation of the stone duster. For example, the compressed air source may be a blower driven by a prime mover via a transmission unit, which may be an axle and gears, a belt and pulleys, or a hydraulic pump and motor. Any suitable drive may be used to drive the hydraulic pump. For example, the pump may include means whereby it can be coupled to a power takeoff point of an engine, for example, the PTO shaft of a tractor. Or alternatively, the drive for the hydraulic pump, or even directly for the blower itself, may be any suitable form of motor, for example, a diesel internal combustion engine or an electrically powered motor. The invention also provides a method of stonedusting, wherein a guniting machine is used to discharge the inert particulate material. Any suitable stoneduster may be used in the apparatus of the invention, but a preferred stone duster is provided by a guniting machine sold under the name "Springbok Rotary Guniter" and manufactured by Turner-Morris (Pty) Limited of Johannesburg. The invention is further described by way of example, with reference to the accompanying drawing which depicts in block diagram form stonedusting apparatus according to the invention. The drawing illustrates in block diagram form a stoneduster 10, an air blower 12, a hydraulic motor 14, a hydraulic pump 16 and an engine 18. The stoneduster 10 in this example of the invention is a guniting machine which is manufactured by Turner-Morris (Pty) Limited of Johannesburg and sold under the name "Springbok Rotary Guniter". It includes an inlet nozzle 20 which is connected to the compressed air outlet nozzle of the blower 12, and a feeding nozzle 22 through which limestone dust or any other suitable inert material is supplied to the stoneduster. The blower 12 is powered by means of the hydraulic motor 14 which in turn is powered by hydraulic fluid pressurised by the hydraulic pump 16. The hydraulic pump in turn is connected to the engine 18. The engine may for example be the engine of a tractor in which event the hydraulic pump may conveniently be coupled to the PTO shaft of the tractor. The use of a tractor enables the unit to be transported and also provides power for the blower 12. In place of the hydraulic transmission via a pump 16 and motor 14 as shown, the blower may be connected via a gear system to the power takeoff shaft of a tractor. Alternately, a separate motor such as an electrically powered motor or a diesel motor may drive the blower directly. A self-powered compressor could also be used. The stoneduster 10 is used in a conventional way and the inert material supplied to it through the nozzle 22 is blown out through an exit nozzle 24 under the action of the compressed air. The particular utility and benefit of the invention lies in the fact that use may be made of an engine 18 which normally is used for other purposes. The engine is therefore not dedicated to the blower 12 and consequently the stonedusting apparatus can be implemented at a comparatively low cost. The use of an hydraulic interface between the engine and the blower provides an inexpensive and robust means of controlling the operation of the stoneduster. CLAIMS

1. Stonedusting apparatus which comprises an air powered stoneduster and a source of compressed air arranged to feed air to the stoneduster.

2. Apparatus as claimed in Claim 1, wherein the source of compressed air is a blower.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein the stoneduster is a guniting machine.

4. Apparatus as claimed in any preceding claim mounted on a tractor.

5. Apparatus as claimed in Claim 4, wherein the source of compressed air is driven by a power takeoff shaft of the tractor.

6. A method of stonedusting, wherein a guniting machine is used to discharge the inert particulate material.

7. Stonedusting apparatus substantially as herein described with reference to the accompanying drawing.