Pulp thickener having two vertical perforated screens with nonmoving spirally wrapped blades therebetween

Claim 2

A pulp thickener comprising means defining a flow chamber having an inlet thereto and an outlet therefrom, said flow chamber being defined by at least pair of tubular elements one of which is positioned within the other and at least one of which is apertured, two helically wrapped blade elements displaced about 180*, one leading from said inlet and the other terminating at said outlet, said blade elements having a spiral disposition between said tubular elements and a fixed position inhibiting movement thereof within said chamber, said blade elements forming flow guides and individually defining the base of a separate portion of a flow path extending from said inlet to said outlet, a pulp slurry moved through said path from one portion to another having fluid expressed therefrom through an apertured portion of said flow chamber, said inlet and said outlet being to the same end of said flow chamber and said means defining said flow chamber further including a housing forming a drain receptacle for expressed fluid.

Claim 3

A pulp thickener without moving parts and located in a system flowing a pulp slurry under pressure, including a vertically oriented shell, a pair of concentric tubular screens mounted on end in said shell and defining with said shell inner and outer annular spaces as well as a central space in the inner one of said screens, both the outer annular space as well as said central space, draining to the bottom of said shell, means defining a reversing spiral channel in said inner annular space in simultaneous continuous communication through said screens with said outer annular space and said central space, and inlet and outlet means in said shell located at one end of said shell to admit a relatively thin pulp slurry to said spiral channel and to discharge a thickened slurry therefrom, the consistency of the pulp slurry being affected by an expression of liquid through said screens.

Claim 4

A pulp thickener without moving parts and located in a system flowing a pulp slurry under pressure, including a vertically oriented shell, a pair of concentric tubular screens mounted on end in said shell and defining with said shell inner and outer annular spaces as well as a central space in the inner one of said screens, both the outer annular space as well as said central space, draining to the bottom of said shell, means defining a reversing spiral channel in said inner annular space in simultaneous continuous communication through said screens with said outer annular space and said central space, and inlet and outlet means in said shell located at one end of said shell to admit a relatively thin pulp slurry to said spiral channel and to discharge a thickened slurry therefrom, the consistency of the pulp slurry being affected by an expression of liquid through said screens.

Claim 5

A pulp thickener according to claim 2, wherein said spiral channel is formed by helical means disposing in said inner annular space having opposite side edges in substantially contacting relation to respective screens and providing a continuously inclining surface over which the pulp slurry flows in moving from said inlet means to said outlet means.

Claim 6

A pulp thickener according to claim 3, wherein said helical means defines a flow path having said inlet means and said outlet means at opposite terminals thereof.

Claim 7

A pulp thickener without moving parts and located in a system flowing a pulp slurry under pressure, including a vertically oriented shell, a pair of concentric tubular screens mounted on end in said shell and defining with said shell inner and outer annular spaces as well as a central space in the inner one of said screens, both the outer annular space as well as said central space, draining to the bottom of said shell, means defining a spiral channel in said inner annular space in simultaneous continuous communication through said screens with said outer annular space and said central space, said spiral channel being formed by helical means disposing in said inner annular space having opposite side edges in substantially contacting relation to respective screens and providing a continuously inclining surface defining a flow path, and inlet and outlet means in said shell located at opposite terminals of said flow path to admit a relatively thin pulp slurry thereto and to discharge a thickened slurry therefrom, the consistency of the pulp slurry being affected by an expression of liquid through said screens, said inlet means and said outlet means being at the same end of said shell, the flow path defined by said helical means extending continuously in a direction outward of said one end of the shell and then reversely back to said one end.

Claim 8

A pulp thickener without moving parts and located in a system flowing a pulp slurry under pressure, including a vertically oriented shell, a pair of concentric tubular screens mounted on end in said shell and defining with said shell inner and outer annular spaces as well as a central space in the inner one of said screens, both the outer annular space as well as said central space, draining to the bottom of said shell, means defining a spiral channel in said inner annular space in simultaneous continuous communication through said screens with said outer annular space and said central space, said spiral channel being formed by helical means disposing in said inner annular space having opposite side edges in substantially contacting relation to respective screens and providing a continuously inclining surface defining a flow path, and inlet and outlet means in said shell located at opposite terminals of said flow path to admit a relatively thin pulp slurry thereto and to discharge a thickened slurry therefrom, the consistency of the pulp slurry being affected by an expression of liquid through said screens, said inlet means and said outlet means being at the same end of said shell, the flow path defined by said helical means extending continuously in a direction outward of said one end of the shell and then reversely back to said one end.

Claim 9

A pulp thickener according to claim 5, wherein said helical means in the form of two helically wrapped blade elements forming separate flow path portions in respectively separate communicaTion at their one ends with said inlet and outlet means and in open communication with another at their opposite ends.

Claim 10

A pulp thickener according to claim 6, wherein said inlet and outlet means are in the lower end of the shell, characterized by closure means for said lower end of the shell providing a seat for said screens and incorporating openings providing said inlet and outlet means and a drain for expressed liquid.

Claim 11

A pulp thickener without moving parts comprising a flow chamber defined by at least one pair of tubular elements one of which is positioned within the other and at least one of which is apertured, a plurality of helically wrapped blade elements displaced from one another between said tubular elements and defining therewith a reversing flow path in said flow chamber, inlet means for directing a thin slurry into one end of said flow path at one end of said chamber, and outlet means for discharging a thickened slurry from a remote end of said flow path at the same said end of said chamber.

Claim 12

A pulp thickener without moving parts comprising a flow chamber defined by at least one pair of tubular elements one of which is positioned within the other and at least one of which is apertured, a plurality of helically wrapped blade elements displaced from one another between said tubular elements and defining therewith a reversing flow path in said flow chamber, inlet means for directing a thin slurry into one end of said flow path at one end of said chamber, and outlet means for discharging a thickened slurry from a remote end of said flow path at the same said end of said chamber.

Claim 13

A pulp thickener according to claim 8, wherein both said tubular elements are apertured, characterized by a shell surrounding said tubular elements and defining therewith inner and outer annular spaces, said inwardly positioned tubular element defining a central space, both said outer annular space and said central space draining to the bottom of said shell and said helically wrapped blade elements occupying said inner annular space, said thickener orienting to dispose one end relatively lower than the other, the lower end of the shell defining the bottom thereof, and closure means at the said bottom end of said shell providing therein said slurry inlet and outlet and a drain for fluids escaping from said inner annular space into said outer annular space and said central space.