Dry fiber distribution

Claim 2

In the known apparatus for producing a web of dry fibers and comprising a suction box structure having a substantially rectangular top opening, a movable belt-like and gas-permeable screen extending over said top opening of the suction box structure, a hood-like cover extending over said top opening of the suction box structure and above the screen to form a fiber distribution chamber in which said screen forms a substantially horizontal bottom, said distribution chamber having a fiber inlet opening vertically spaced from said movable screen, means for moving said screen longitudinally over said top opening of the suction box structure, a vertical shaft communicating at its upper end with said fiber inlet opening of the distribution chamber, means for creating a flow of gas upwardly through said vertical shaft, into said distribution chamber, downwardly through said screen and out through said suction box structure, means for suspending fibers in the gas stream rising through said vertical shaft, the improvement which comprises: said vertical shaft being generally rectangular in horizontal cross section and extending across the full width of said distribution chamber and being separated from said distribution chamber by a substantially upright partition wall member extending transversely of the running direction of said screen, said partition wall member forming the rear wall of the distribution chamber, said distribution chamber having a section extending in the running direction of said screen that resembles a sector of a circle, of which one bounding radius is represented by said screen, the other bounding radius is represented by said partition wall member and the arc is represented by a curved wall member forming part of said hoodlike cover, said curved wall member being extended beyond the upper edge of said partition wall member to form a substantially horizontal top cover for said vertical shaft and being vertically spaced from said partition wall member so as to define with the latter and above the same an opening extending in a vertical plane and representing said fiber inlet opening of the distribution chamber, a slot-like gas inlet opening being provided at the upper end of said vertical shaft and horizontally opposite to said fiber inlet opening for the introduction of a second stream of gas in a substantially horizontal direction across the upper portion of said vertical shaft and immediately beneath said horizontal top cover thereof and into said distribution chamber.

Claim 3

An apparatus according to claim 1, wherein said slotlike gas inlet opening for the introduction of the second gas stream is variable as to its size.

Claim 4

An apparatus according to claim 2, wherein said slotlike gas inlet opening is variable as to its configuration.

Claim 5

In the known apparatus for producing a web of dry fibers and comprising a suction box structure having a substantially rectangular top opening, a movable belt-like and gas-permeable screen extending over said top opening of the suction box structure, a hood-like cover extending over said top opening of the suction box structure and above the screen to form a fiber distribution chamber in which said screen forms a substantially horizontal bottom, said distribution chamber having a fiber inlet opening vertically spaced from said movable screen, means for moving said screen longitudinally over said top opening of the box structure, a vertical shaft communicating at its upper end with said fiber inlet opening of the distribution chamber, means for creating a flow of gas upwardly through said vertical shaft, into said distribution chamber, downwardly through said screen and out through said suction box structure, means for suspending fibers in the gas stream rising through said vertical shaft, the improvement which comprises: said vertical shaft being generally rectAngular in horizontal cross section and extending across the full width of said distribution chamber and being separated from said distribution chamber by a substantially upright partition wall member extending transversely of the running direction of said screen, said partition wall member forming the rear wall of the distribution chamber, said distribution chamber having a section extending in the running direction of said screen that resembles a sector of a circle, of which one bounding radius is represented by said screen, the other bounding radius is represented by said partition wall member and the arc is represented by a curved wall member forming part of said hood-like cover, said curved wall member being extended beyond the upper edge of said partition wall member to form a substantially horizontal top cover for said vertical shaft and being vertically spaced from said partition wall member so as to define with the latter and above the same an opening extending in a vertical plane and representing said fiber inlet opening of the distribution chamber, an adjustable slot-like gas inlet opening being provided at the upper end of said vertical shaft and horizontally opposite to said fiber inlet opening for the introduction of a second stream of gas in a substantially horizontal direction across the upper portion of said vertical shaft and immediately beneath said horizontal top cover thereof and into said distribution chamber, said arc-forming, curved wall member having at least one inlet opening located approximately midway between the ends of the arc formed thereby, said at least one gas inlet opening being provided for the introduction of an additional stream of gas in a mainly downward direction through said distribution chamber towards said movable screen.

Claim 6

In the known apparatus for producing a web of dry fibers and comprising a suction box structure having a substantially rectangular top opening, a movable belt-like and gas-permeable screen extending over said top opening of the suction box structure, a hood-like cover extending over said top opening of the suction box structure and above the screen to form a fiber distribution chamber in which said screen forms a substantially horizontal bottom, said distribution chamber having a fiber inlet opening vertically spaced from said movable screen, means for moving said screen longitudinally over said top opening of the box structure, a vertical shaft communicating at its upper end with said fiber inlet opening of the distribution chamber, means for creating a flow of gas upwardly through said vertical shaft, into said distribution chamber, downwardly through said screen and out through said suction box structure, means for suspending fibers in the gas stream rising through said vertical shaft, the improvement which comprises: said vertical shaft being generally rectAngular in horizontal cross section and extending across the full width of said distribution chamber and being separated from said distribution chamber by a substantially upright partition wall member extending transversely of the running direction of said screen, said partition wall member forming the rear wall of the distribution chamber, said distribution chamber having a section extending in the running direction of said screen that resembles a sector of a circle, of which one bounding radius is represented by said screen, the other bounding radius is represented by said partition wall member and the arc is represented by a curved wall member forming part of said hood-like cover, said curved wall member being extended beyond the upper edge of said partition wall member to form a substantially horizontal top cover for said vertical shaft and being vertically spaced from said partition wall member so as to define with the latter and above the same an opening extending in a vertical plane and representing said fiber inlet opening of the distribution chamber, an adjustable slot-like gas inlet opening being provided at the upper end of said vertical shaft and horizontally opposite to said fiber inlet opening for the introduction of a second stream of gas in a substantially horizontal direction across the upper portion of said vertical shaft and immediately beneath said horizontal top cover thereof and into said distribution chamber, said arc-forming, curved wall member having at least one inlet opening located approximately midway between the ends of the arc formed thereby, said at least one gas inlet opening being provided for the introduction of an additional stream of gas in a mainly downward direction through said distribution chamber towards said movable screen.

Claim 7

An apparatus according to claim 4 wherein each of said at least one gas inlet opening of the distribution chamber is variable as to its size.

Claim 8

An apparatus according to claim 4 wherein each of said at least one gas inlet opening of the distribution chamber is adjustable as to its position.

Claim 9

An apparatus according to claim 4 wherein each of said at least one gas inlet opening of the distribution chamber is variable as to its configuration.

Claim 10

An apparatus according to claim 7 wherein individually adjustable damper means are provided adjacent each of said at least one gas inlet opening of the distribution chamber to vary the size and configuration thereof.

Claim 11

An apparatus according to claim 8 wherein means for sensing the thickness of the fiber web formed on said movable screen are provided at points distributed transversely of said screen and actuating means are provided for adjusting the setting of said damper means in accordance with the input to said thickness sensing means.

Claim 12

An apparatus according to claim 4 wherein the running direction of said movable screen is reversible.

Claim 13

An apparatus according to claim 4 wherein said distribution chamber is provided with a roller that is movable towards and away from said screen and adapted to ride on said fiber web, and a hinged flap connected in sealing engagement with a transverse wall member of said distribution chamber rests on said roller.

Claim 14

An apparatus according to claim 4 wherein said open box under said movable screen is a suction box and said means for creating a flow of gas is a suction source connected to said box.

Claim 15

An apparatus according to claim 4 wherein said means for suspending fibers in the gas stream rising through said shaft comprises a rotary disintegrator for breaking up collections of tangled fibers and for throwing the freed fiber into said vertical shaft and wherein the lower end of said vertical shaft is connected to a chamber, at the bottom of which conveyor means are provided for removing residues of fiber material which the rising stream of gas in said shaft is unable to carry upwardly into said distribution chamber.