Pulp picking apparatus with improved fiber forming duct

Claim 2

In an apparatus for forming an airlaid web which comprises a rotatable divellicating means having teeth thereon for separating a compacted fiber sheet into its individual fibers, a housing enclosing the divellicating means and providing a passage between the housing and the divellicating means, a foraminous moving surface for collecting the fibers to form a web thereon, a forming duct positioned between the divellicating means and the moving surface through which the separated fibers leaving the divellicating means are transported to the moving surface and communicating with the passage, a suction means disposed below the foraminous surface to assist in collecting the fibers on the surface and wherein the rotation of the divellicating means creates a pumping action in the passage to provide moving process air for transporting the separated fibers through the forming duct to the collecting surface and the pumping action tends to cause part of the process air to enter the passage, the improvement comprising said forming duct having a limited area path through which the separated fibers and process air are transported to the collecting surface, the width of said forming duct being approximately equal to the height of the teeth of said divellicating means, a process air duct communicating with the passage and means for supplying air to said process air duct at a pressure and a rate sufficient to substantially prevent process air in said forming duct from entering the passage.

Claim 3

The apparatus of claim 1 wherein said forming duct and process air duct have a common wall and said process air duct is positioned to cause the process air to communicate with the passage adjacent the point at which said forming duct communicates with the passage.

Claim 4

The apparatus of claim 1 and wherein the longitudinal axis of said forming duct is inclined with respect to the perpendicular to the foraminous surface.

Claim 5

In an apparatus for forming an airlaid web which comprises a rotatable divellicating means having teeth thereon for separating a compacted fiber sheet into its individual fibers, a housing enclosing the divellicating means and providing a passage between the housing and the divellicating means, a foraminous moving surface for collecting the fibers to form a web thereon, a forming duct positioned between the divellicating means and the moving surface through which the separated fibers leaving the divellicating means are transported to the moving surface and communicating with the passage, a suction means disposed below the foraminous surface to assist in collecting the fibers on the surface and wherein the rotation of the divellicating means creates a pumping action in the passage to provide moving process air for transporting the separated fibers through the forming duct to the collecting surface and the pumping action tends to cause part of the process air to enter the passage, the improvement comprising said forming duct having a limited area path through which the separated fibers and process air are transported to the collecting surface, a process air duct communicating with the passage, means for supply air to said process air duct at a pressure and at a rate sufficient to substantially prevent process air in said forming duct from entering the passage, a supplemental air duct communicating with said forming duct and positioned to allow air to enter said forming duct at a point adjacent the entry of the separated fibers into said forming duct and in the same directioN as the process air, said forming duct width being up to about four times the height of the divellicating means teeth and means for supplying air to said supplemental air duct to provide entry of the supplemental air into said forming duct at substantially the same velocity as the process air.

Claim 6

In an apparatus for forming an airlaid web which comprises a rotatable divellicating means having teeth thereon for separating a compacted fiber sheet into its individual fibers, a housing enclosing the divellicating means and providing a passage between the housing and the divellicating means, a foraminous moving surface for collecting the fibers to form a web thereon, a forming duct positioned between the divellicating means and the moving surface through which the separated fibers leaving the divellicating means are transported to the moving surface and communicating with the passage, a suction means disposed below the foraminous surface to assist in collecting the fibers on the surface and wherein the rotation of the divellicating means creates a pumping action in the passage to provide moving process air for transporting the separated fibers through the forming duct to the collecting surface and the pumping action tends to cause part of the process air to enter the passage, the improvement comprising said forming duct having a limited area path through which the separated fibers and process air are transported to the collecting surface, a process air duct communicating with the passage, means for supply air to said process air duct at a pressure and at a rate sufficient to substantially prevent process air in said forming duct from entering the passage, a supplemental air duct communicating with said forming duct and positioned to allow air to enter said forming duct at a point adjacent the entry of the separated fibers into said forming duct and in the same directioN as the process air, said forming duct width being up to about four times the height of the divellicating means teeth and means for supplying air to said supplemental air duct to provide entry of the supplemental air into said forming duct at substantially the same velocity as the process air.