Main roll for an air press of a papermaking machine
AssigneeVoith Paper Patent GmbH
InventorDavid A. Beck
Life of this patent
Estimating the term…
Abstract
A roll for use in an air press assembly of a papermaking machine has a pair of ends associated therewith. The roll includes a pair of edge portions with each edge portion extending to one of the pair of ends. Each edge portion has an edge surface portion composed of a first material, the first material having a first hardness. The roll further includes a middle portion located between the pair of edge portions, the middle portion having a middle surface portion composed of a second material. The second material has a second hardness, the second material being harder than the first material. The first material is preferably a soft, seal material which promotes reduced air leakage from the air press assembly.
Claims15
An air press for removing liquid from a web, said air press comprising:
- a plurality of rolls including at least one first roll, each first roll having a pair of ends associated therewith, each first roll comprising:
- a pair of edge portions, each edge portion extending to one of said pair of ends, each said edge portion having an edge surface portion composed of a first material;
- and
- a middle portion located between said pair of edge portions, said middle portion having a middle surface portion composed of a second material, said second material having a second hardness, said second material being harder than said first material.
An air press assembly roll, for sealing an air press pressure chamber in a papermaking machine, said roll having a pair of ends associated therewith, said roll comprising:
- a pair of edge portions, each edge portion extending to one of said pair of ends, each edge portion having an edge surface portion composed of a first material, said first material having a first hardness;
- and
- a middle portion located between said pair of edge portions, said middle portion having a middle surface portion composed of a second material, said second material having a second hardness said second material being harder than said first material;
- wherein each edge surface portion is configured to wear at a faster rate than said middle surface portion and has a maximum mounted edge surface portion diameter, said middle surface portion having a maximum mounted middle surface portion diameter, said maximum mounted edge surface portion diameter being greater than said maximum mounted middle surface portion diameter.
An air press assembly roll, for sealing an air press pressure chamber in a papermaking machine, said roll having a pair of ends associated therewith, said roll comprising:
- a pair of edge portions, each edge portion extending to one of said pair of ends, each edge portion having an edge surface portion composed of a first material, said first material having a first hardness;
- and
- a middle portion located between said pair of edge portions, said middle portion having a middle surface portion composed of a second material, said second material having a second hardness, said second material being harder than said first material;
- wherein each edge surface portion is replaceably mounted upon said roll.
An air press assembly roll, for sealing an air press pressure chamber in a papermaking machine, said roll having a pair of ends associated therewith, said roll comprising:
- a pair of edge portions, each edge portion extending to one of said pair of ends, each edge portion having an edge surface portion composed of a first material, said first material having a first hardness;
- and
- a middle portion located between said pair of edge portions, said middle portion having a middle surface portion composed of a second material, said second material having a second hardness, said second material being harder than said first material;
- wherein each edge surface portion is at least one of formed so as to have a crown and fastened under compression to create a bulge therein.
A method of dewatering a fiber web using an air press, said method comprising the steps of:
- providing an air press for pressing a fiber web, said air press comprising:
- at least one cap roll including a first cap roll;
- and
- at least one main roll including a first main roll, said first cap roll and said first main roll forming a first nip therebetween, each main roll having a pair of ends associated therewith, each main roll comprising:
- a pair of edge portions, each edge portion extending to one of said pair of ends, each edge portion having an edge surface portion composed of a first material, said first material having a first hardness;
- and
- a middle portion located between said pair of edge portions, said middle portion having a middle surface portion composed of a second material, said second material having a second hardness, said second material being harder than said first material;
- forming a seal between said pair of edge portions of said first main roll and said first cap roll;
- and
- feeding the fiber web through said first nip into said air press.
A papermaking machine for making a fiber web, the papermaking machine comprising:
- a plurality of rolls for carrying the fiber web;
- an air press for pressing a fiber web, said air press comprising:
- a plurality of rolls including at least one first roll, each first roll having a pair of ends associated therewith, each first roll comprising:
- a pair of edge portions, each edge portion extending to one of said pair of ends, each edge portion having an edge surface portion composed of a first material, said first material having a first hardness;
- and
- a middle portion located between said pair of edge portions, said middle portion having a middle surface portion composed of a second material, said second material having a second hardness, said second material being harder than said first material.
Dependencies are inferred from the claim text.