Device for mixing stock suspensions

A mixing device for blending of additional suspensions into a first suspension in a stable section of a paper machine, comprising:

• a tube;
• an intake in said tube for the first suspension, said first suspension having a negligible solid content and forming a main flow;
• a plurality of feeds into said tube for the additional suspensions to be blended with said first suspension into a blended suspension with a new solid content, said additional suspensions having a higher solid content than the first suspension;
• an outlet in said tube for the blended suspension, said outlet being disposed downstream from a bend in said tube,
• wherein each feed of said plurality of feeds injects an additional suspension having a solid content equal to or greater than a previous feed along the downstream direction of the main flow.

A mixing device for blending of additional suspensions into a backwater suspension in a stable section of a paper machine, comprising:

• a closed vertical mixing tube having a bend at a lower end thereof;
• an intake at a top of said mixing tube for a backwater suspension from a wet section of the paper machine, said backwater suspension forming a main flow;
• a first concentric nozzle that injects accepted stock, having a higher solid content than said backwater suspension, from a vertical separator system into said mixing tube to form a blended suspension, said first concentric nozzle being concentric to said mixing tube and upstream of said bend, and injecting said accepted stock at a higher flow rate than said main flow;
• a second concentric nozzle that injects fresh stock having a higher solid content than said blended suspension into said mixing tube, said second concentric nozzle being concentric to said mixing tube and downstream of said bend, and injecting said fresh stock at a higher flow rate than said blended suspension;
• and
• an outlet in said tube, said outlet being disposed downstream from said bend and from said second concentric nozzle.

A mixing device for blending of additional suspensions into a first suspension in a stable section of a paper machine, comprising:

• a tube comprising a bend;
• an intake in said tube for the first suspension, said first suspension having a first solid content;
• a plurality of feed lines connected to said tube, each feed line supplying an additional suspension to be blended with said first suspension into a blended suspension with a new solid content, at least one of the additional suspensions having higher solid content than the first suspension;
• a feed line supplying suspension from a wet section of the paper machine to the intake of said tube;
• each of the plurality of feed lines being coupled to a nozzle which has a nozzle outlet concentrically arranged in said tube;
• each nozzle supplying additional suspension upstream from the bend in said tube;
• an outlet in said tube for the blended suspension, said outlet being disposed downstream from the bend in said tube;
• and
• a pump connected to said tube downstream from said outlet,
• wherein each of said plurality of feeds injects an additional suspension having a solid content equal to or greater than a previous feed along the downstream direction of a main flow.