Method with a horizontal jet applicator for a paper machine wet end

Abstract

A method applying additives to a forming web of paper fiber by pumping an additive through a channel in an applicator to a horizontal slot with a vertical gap of less than 0.100 inch at a rate of less than 5 US gallons per minute per inch of the slot, the additive leaving the slot in a substantially horizontal direction above the forming web traveling in a substantially horizontal direction.

1 . A method of applying additives to a forming web of paper fiber, the method comprising pumping an additive in a fluid through a channel in an applicator to a horizontal slot with a vertical gap height of less than 0.100 inch at a rate of less than 5 US gallons per minute per inch of the slot, the additive leaving the slot in a substantially horizontal direction above the forming web traveling in a substantially horizontal direction. 
     
     
         2 . The method according to  claim 1  wherein the slot is formed from long, essentially parallel lips. 
     
     
         3 . The method according to  claim 2  wherein the essentially parallel lips have an angle between the top surface of the bottom lip and the bottom surface of the top lip of less than 3 degrees. 
     
     
         4 . The method according to  claim 1  wherein the percent by weight of the additive in fluid is less than about 4%. 
     
     
         5 . The method according to  claim 4  wherein the percent by weight of the additive in fluid is less than about 1.5%. 
     
     
         6 . The method according to  claim 1  wherein the slot gap height is between 0.015 and 0.060-inches. 
     
     
         7 . The method according to  claim 1  wherein the additive enters the applicator through an expansion chamber where the additive then accumulates behind a restriction to ensure its even distribution through an about 0.120-inch channel into a nozzle chamber where the additive then gets distributed evenly across and through the horizontal slot. 
     
     
         8 . The method according to  claim 7  wherein applicator chambers inside the applicator through which the additive passes are small enough to keep the additive fluid. 
     
     
         9 . The method according to  claim 8  wherein flow inside the applicator maintains micro turbulence of the additive. 
     
     
         10 . The method according to  claim 1  wherein the additive is microfibril. 
     
     
         11 . The method according to  claim 1  wherein pumping is at a rate of between 1 to 2 US gallons per minute per inch of the slot. 
     
     
         12 . The method according to  claim 1  wherein the velocity of the additive leaving the slot is about the same as the speed of the forming web traveling in the substantially horizontal direction.