Blower and dust collecting machine and method of operation

Apparatus for maintaining a low dust level in a coal mine about the face of the coal as it is mined comprising

• (a) a mobile blower having a closed housing containing an intake opening and an exhaust opening spaced therebehind in straight line relation;
• (b) an evacuating fan in the exhaust opening of the blower which pulls a continuous stream of air through the blower housing from its air intake opening and discharges the air through its exhaust opening in a direction away from the face of the coal being mined;
• and
• (c) a first stage of closely-spaced, small-diametered, cylindrically-shaped individual centrifuges which occupy the cross-section of the housing upstream of the evacuating fan;
• (d) said individual centrifuges each having an inlet toward the intake opening, an outlet end toward the exhaust opening of the blower housing and means to effectively spin the dust-laden air as it enters the individual centrifuges under the pull of the evacuating fan such that the dust content of said air is concentrated at the sides of the centrifuges and dust-freed air is drawn from the central core of the centrifuges through their outlets under the pull of the exhaust fan;
• (e) air tight conduit means separate from said housing having one open end in communication with the evacuating fan therebetween and the first stage, the opposite end of said conduit means communicating with the sides of the centrifuges against which the dust is concentrated whereby the evacuating fan simultaneously pulls a dust-concentrated air portion off the sides of the centrifuges into the air-tight conduit means as it pulls air through the closed housing from the outlets of the first stage of centrifuges;
• (f) said air-tight conduit means including a dust-collecting area spaced between the centrifuges and the evacuating fan;
• and
• (g) means in the conduit means adapted to separate the dust content from said air as it is pulled through the conduit means and discharges it into the dust collecting area;
• (h) whereby only the air thus separated of dust continues through the conduit means to the exhaust fan under the pull thereof.

A method of maintaining a low level of coal dust in a coal mine comprising the steps of

• (a) locating an evacuating fan in the discharge end of a main passageway leading from the coal face being cut so as to draw a mainstream of air from the coal face in which the coal dust particles generated by the coal-cutting action are caught;
• (b) dividing said main airstream into smaller diametered columns and spinning each said columns to concentrate the coal dust particles into an annular portion about the dust-freed center core of said columns;
• (c) simultaneously causing the exhaust fan to draw said dust-concentrated air from said annular portions of the mainstream and into a communicating secondary passageway which leads from said annular portions of the mainstream to upstream of the evacuating fan;
• (d) discharging a portion of said coal dust particles from the stream of air being drawn through the secondary passageway;
• (e) collecting said discharged coal dust particles;
• (f) concentrating the dust particles remaining in said secondary stream into an indentifiable portion of said second stream;
• and
• (g) separating out and collecting said dust particles from said indentifiable portion;
• (h) the thus dust-freed secondary airstream combining with the main airstream for discharge into the mine and so that only air of low dust content is discharged by the evacuating fan.

A method of maintaining a low dust level in a coal mine comprising the steps of

• (a) locating an evacuating fan in the exhaust end of a main passage which leads from adjacent the coal face where coal dust particles are created so as to draw a continuous mainstream of dust-laden air from said coal face as it is generated for discharge into the mine area in a direction away from the coal face being cut;
• (b) dividing said dust-laden main airstream into a plurality of smaller-diametered columns;
• (c) spinning each said smaller-diametered columns of air so as to free the dust from the center core thereof and concentrate the dust in a surrounding annular portion, and
• (d) while continuing to draw freed air from the core of said spinning columns simultaneously causing said evacuating fan to pull a secondary stream of air from the said surrounding portions in which the dust is concentrated;
• (e) reversely bending the secondary stream to discharge its dust content;
• (f) collecting said dust as it is discharged from said secondary stream;
• and
• (g) combining said secondary stream of air with the mainstream immediately ahead of the evacuating fan wherefore the evacuating fan discharges only air of low dust content.

In a process where large volumes of air are blown across the coal face being mined to dilute, disperse and remove noxious gases including methane therefrom, and the air is polluted with coal dust generated in the mining act, the improvement comprising the steps of

• (a) relying on the pull of an evacuating fan to draw a mainstream of air from adjacent the coal face in which the coal dust gathers as it is generated;
• (b) dividing said mainstream air upstream of the evacuating fan into a plurality of smaller-diametered columns of air which are axially spun to radially move and concentrate the dust about the center core of said columns;
• (c) diverting a portion of the pull of said evacuating fan so as to draw air from about the core of the smaller-diametered columns in which the dust is concentrated through a secondary passage separate from the passage mainstream of air is passed through;
• (d) discharging the dust from said air drawn through the secondary passage;
• and
• (e) collecting said dust as it discharges from the air drawn through said secondary passage whereby only air of low dust content is returned to the mine.