Probe for removing dust from moving webs

A probe for removing dust from moving paper webs, comprising at least one electrostatic high-voltage electrode;

• at least one air blower oriented against the direction of web movement;
• a vacuum channel for suctioning up dust-laden air;
• said high-voltage electrode comprising subsidiary electrodes lying in a first plane substantiallyy perpendicular to said web;
• said blower having a row of nozzles blowing along a direction lying in a second plane inclined with respect to said first plane;
• said blower being located downstream of said high-voltage electrode in direction of web movement;
• said two planes intersecting at a line lying in a plane of the web and extending across said web;
• and openings into said vacuum channel being positioned upstream of said high-voltage electrode direction of web movement;
• said air blower blowing air in a direction opposite to direction of web movement for breaking up an air stream of substantially laminar flow moving with said web to produce turbulence that picks up dust through the turbulence;
• said nozzles on said blower having a direction to apply an air stream onto said openings in said vacuum channel for producing maximum suction of air particles carried by the turbulence;
• said electrostatic high-voltage electrode being located in vicinity of the dust picked up by the turbulence;
• said subsidiary electrodes comprising pointed electrodes.

A probe for removing dust from moving paper webs, comprising at least one electrostatic high-voltage electrode;

• at least one air blower oriented against the direction of web movement;
• a vacuum channel for suctioning up dust-laden air;
• said high-voltage electrode comprising subsidiary electrodes lying in a first plane substantially perpendicular to said web;
• said blower having a row of nozzles blowing along a direction lying in a second plane inclined with respect to said first plane;
• said blower being located downstream of said high-voltage electrode in direction of web movement;
• said two planes intersecting at a lying in a plane of the web and extending across said web;
• and openings onto said vacuum channel being positioned upstream of said high-voltage electrode web-travel direction;
• said air blower air in a direction opposite to direction of web movement for breaking up an air stream of substantially laminar flow moving with said web to produce turbulence that picks up dust through the turbulence;
• said nozzles on said blower having a direction to apply an air stream onto said openings in said vacuum channel for producing maximum suction of air particles carried by the turbulence;
• said electrostatic high-voltage electrode being located in vicinity of the dust picked up by the turbulence;
• said electrodes being pointed electrodes parallel to one another in said first plane;
• said blower having an additional row of nozzles lying in a third plane intersecting also said line of intersection;
• said nozzles comprising round-shaped bores parallel to one another in said second or third plane;
• said line of intersection being perpendicular to web-travel direction;
• said openings in said vacuum channel being located in vicinity of said web;
• flow into all openings in said vacuum channel having a direction lying within a fourth plane oriented at an acute angle to web-travel direction;
• said probe having a trapezoidal-shaped chamber with larger base and smaller base, said larger base facing said web, said high-voltage electrode having an end located at said smaller base, said blower being positioned on one side of said chamber and inflow opening into said vacuum channel being positioned on another side of said chamber;
• a first ground electrode positioned upstream of said vacuum channel;
• a second ground electrode located downstream of said blower along direction of web movement;
• said ground electrodes being positioned on a bottom facing web and extending over a total width of said probe;
• said ground electrodes being located outside said trapezoidal-shaped recess chamber;
• a metal field plate positioned on a back side of said web and connectable to a source of electric alternating voltage, said field plate being parallel to said web;
• and suction slot means extending across said web.