Apparatus for the removal of liquids from fibrous materials

Claim 1

An apparatus according to claim 1, in which the space between said filter means and said casing means in said filter section is substantially sealed from the corresponding space in said press section, vacuum applying means coupled to said space in said filter section, said suspension supplying means including means for applying a superatmospheric pressure to the suspension inside the filter means in the filter section.

Claim 5

An apparatus for removing liquid from a suspension of liquid and fibrous solids, comprising: casing means defining a press section, said casing means having liquid discharge means; cylindrical liquid pervious filter means disposed within said casing means for permitting liquid to flow from within said filter means into said casing means for discharge therefrom; a rotatable spindle disposed within said cylindrical filter means in substantially concentric relation thereto; screw flight means mounted on said spindle and projecting therefrom toward the filter means for forwarding the suspension from the inlet end of the press section to the outlet end thereof and for expRessing liquid from the suspension as it travels through the press section; said spindle having an unflighted portion adjacent the discharge end of the press section, said unflighted portion being located within said filter means and defining therewith an annular zone whereby an annular ring of pressed fiber cake is formed around said unflighted portion adjacent the discharge end of the press section, said unflighted portion of the spindle and the portions of the filter means and casing means surrounding said unflighted portion being separable, respectively, from the remainder of the spindle, the filter means and the casing means.

Claim 7

An apparatus for removing liquid from a suspension of liquid and fibrous solids, comprising: casing means defining a press section, said casing means having liquid discharge means; cylindrical liquid pervious filter means disposed within said casing means for permitting liquid to flow from within said filter means into said casing means for discharge therefrom; a rotatable spindle disposed within said cylindrical filter means in substantially concentric relation thereto; screw flight means mounted on said spindle and projecting therefrom toward the filter means for forwarding the suspension from the inlet end of the press section to the outlet end thereof and for expressing liquid from the suspension as it travels through the press section; said spindle having an unflighted portion adjacent the discharge end of the press section, said unflighted portion being located within said filter means and defining therewith an annular zone whereby an annular ring of pressed fiber cake is formed around said unflighted portion adjacent the discharge end of the press section; a dilution section coupled to the discharge end of the press section and being in communication therewith for receiving the pressed fiber cake therefrom, said dilution section being substantially closed to the admission of gas and having means for supplying a dilution liquid to the interior thereof, agitation means within the dilution section for breaking up the pressed fiber cake and for mixing the dilution liquid with the fibrous material so that as the fibrous material expands upon release of the pressing force applied in the press section, the dilution liquid will be sucked into the fibers; and means for discharging the diluted fibrous material from the dilution section.

Claim 8

An apparatus for removing liquid from a suspension of liquid and fibrous solids, comprising: casing means defining a press section, said casing means having liquid discharge means; cylindrical liquid pervious filter means disposed within said casing means for permitting liquid to flow from within said filter means into said casing means for discharge therefrom; a rotatable spindle disposed within said cylindrical filter means in substantially concentric relation thereto; screw flight means mounted on said spindle and projecting therefrom toward the filter means for forwarding the suspension from the inlet end of the press section to the outlet end thereof and for expressing liquid from the suspension as it travels through the press section; finger means mounted at the discharge end of said press section for relative movement with respect to said spindle, said finger means projecting into the space between said spindle and said filter means for retarding rotation of the pressed fiber cake in order to increase the forces which the screw flight means exert on the suspension being pressed for increasing the liquid removal effect.

Claim 12

An apparatus for removing liquid from a suspension of liquid and fibrous solids, comprising: casing means defining a press section, said casing means having liquid discharge means; cylindrical liquid pervious filter means disposed within said casing means for permitting liquid to flow from within said filter means into said casing means for discharge therefrom; a rotatable spindle disposed within said cylindrical filter means in substantially concentric relation thereto; screw flight means mounted on said spindle and projecting therefrom toward the filter means for forwarding the suspension from the inlet end of the press section to the outlet end thereof and for expressing liquid from the suspension as it travels through the press section; a dilution section attached to the press section for receiving the pressed fiber cake therefrom, said dilution section being closed to the admission of gas and having means for supplying a dilution liquid to the interior of the dilution section, agitation means within the interior of the dilution section for mixing the dilution liquid with the pressed fiber cake so that as the fibrous material expands upon release of the pressing force applied in the press section, the diluting liquid will be sucked into the fibers; and means for discharging the diluted fibrous mass from the dilution section.

Claim 14

An apparatus for removing liquid from a suspension of liquid and fibrous solids, comprising: a cylindrical filtration screen barrel backed by an apertured strengthening member and whose overall length is designed to provide a retention time appropriate to the deliquoring characteristics in the particular fibrous solids to be processed, the liquid flowing out through the openings in the barrel and the forward-moving fibrous material being retained in the barrel; a solid filtration casing enclosing the filtration screen barrel; a rotating spindle inside the filtration screen barrel and concentric to it; the filtration screen barrel defining a filtration section into which the fibrous suspension is pumped under hydraulic pressure, the diameter of the spindle increasing from the point of entrance of the suspension to the discharge end of the filtration section, the spindle in the filtration section being equipped with a plurality of rotatable scrapers for continuously removing the fiber mat as it is formed on the cylindrical screen and to force said cake toward the spindle and cause mixing of said cake with the main body of the suspension, the filtration casing being isolated from the remainder of the apparatus by means of flanges and means for applying a vacuum to said filtration casing, the pulp entering the filtration section being at a low consistency in the range from about 2.0 percent fibrous solids to about 5.0 percent fibrous solids, the suspension leaving the filtration section being in the range of from about 8.0 percent to about 12.0 percent solids; a pressing section consisting of a cylindrical press screen barrel of the same diameter as the filtration screen barrel for receiving the thickened suspension leaving tHe filtration section, the press screen barrel in the pressing section being surrounded by a solid metal press casing to receive the pressed-out liquid, the rotating spindle extending inside the press screen barrel in the pressing section and being concentric to it, continuous screw flight means attached to the spindle in the pressing section, said flight means being of decreasing pitch from the entering end to near the discharge end of the pressing section, said screw flight means bringing forces to bear on the suspension and forcing liquid out of the suspension through the cylindrical press screen barrel and out into the solid press casing from which the liquid is discharged, said spindle having a short unflighted portion at the discharge end of the pressing section and inside the cylindrical press screen barrel, the pressed cake from the pressing section being discharged as an annular ring of pressed cake at a dry solids content in the range of from about 15 percent to about 60 percent; a plurality of bars having pointed edges extending into the ring of pressed pulp, said bars retarding the rotation of the pressed pulp and thereby increasing the forces which the screw flight means exert against the suspension being pressed and increasing the liquid removal effect; a closed dilution section for receiving the pressed cake and having mechanical agitation means for mixing the cake with a dilution liquid while excluding gas therefrom so that, as the fibrous material expands upon release from the pressing forces of the press section, the diluting liquor will be sucked into the fibers, sufficient additional liquid being added in the dilution section so that the diluted fibrous mass can be discharged from this dilution section.