Abstract: The invention relates to a belt drier arrangement for drying an aqueous polymer gel and for comminuting the dried polymer gel to give dried polymer particles, comprising: a drier setup for drying an aqueous polymer gel, a comminuting arrangement downstream of the drier setup relative to the product flow direction, for comminuting the dried polymer gel to give dried polymer particles. In accordance with the invention the comminuting arrangement comprises at least a first comminutor and a second comminutor, each having a rotatable shaft with functional tools, the second comminutor being disposed downstream of the first comminutor relative to the product flow direction.

Abstract: A process for producing superabsorbents, comprising the steps of i) classifying the superabsorbent particles by means of one or more sieves and ii) removing metallic impurities by means of one or more magnetic separators, wherein classification is accomplished using sieves made of a wire mesh, the wires of the wire mesh consist of a steel composed of at least 70% by weight of iron, at least 10% by weight of chromium and less than 2.5% by weight of nickel, and the throughput of superabsorbent particles in the magnetic separator is in the range from 2.0 to 6.5 g/s per cm2 of free cross-sectional area.

Abstract: A process for producing superabsorbents, comprising polymerization, drying, crushing, pneumatic conveying, comminuting and classifying, wherein the gas temperature at the end of the pneumatic conveying is from 50 to 95° C.

Abstract: The invention relates to a belt drier arrangement for drying an aqueous polymer gel and for comminuting the dried polymer gel to give dried polymer particles, comprising: a drier setup for drying an aqueous polymer gel, a comminuting arrangement downstream of the drier setup relative to the product flow direction, for comminuting the dried polymer gel to give dried polymer particles. In accordance with the invention the comminuting arrangement comprises at least a first comminutor and a second comminutor, each having a rotatable shaft with functional tools, the second comminutor being disposed downstream of the first comminutor relative to the product flow direction.

Abstract: A process for producing superabsorbents, comprising the steps of i) classifying the superabsorbent particles by means of one or more sieves and ii) removing metallic impurities by means of one or more magnetic separators, wherein classification is accomplished using sieves made of a wire mesh, the wires of the wire mesh consist of a steel composed of at least 70% by weight of iron, at least 10% by weight of chromium and less than 2.5% by weight of nickel, and the throughput of superabsorbent particles in the magnetic separator is in the range from 2.0 to 6.5 g/s per cm2 of free cross-sectional area.

Abstract: The invention relates to an apparatus for producing pulverulent poly(meth)acrylate, comprising a reactor for droplet polymerization having an apparatus for dropletization of a monomer solution for the preparation of the poly(meth)acrylate having holes through which the monomer solution is introduced, an addition point for a gas above the apparatus for dropletization, at least one gas withdrawal point on the circumference of the reactor, a fluidized bed and an apparatus for product discharge from the fluidized bed. The apparatus for product discharge comprises a discharge apparatus, with a backup segment (39) disposed above the discharge apparatus.

Abstract: A production process for production of water-absorbing polymer particles including drying an aqueous polymer gel in a belt drier with a conveyor belt. The belt drier is formed with a drier setup substantially comprising the conveyor belt and an air recycling conduit downstream of the drier setup for air recycling, where recycled air is withdrawn from the drier setup and fed back to the drier setup via the air recycling conduit.

Abstract: A production process for production of water absorbing polymer particles, including drying an aqueous polymer gel in a belt drier with a conveyor belt having a drier setup in the interior, in which drying air in the interior of the drier setup is conducted in countercurrent counter to the conveying direction and the interior of the drier setup is kept substantially at a reduced pressure relative to the ambient pressure outside the drier setup, and the interior has and/or forms a pressure zone, and is especially divided into a number of pressure zones.

Abstract: A process for producing superabsorbents, comprising polymerization, drying, crushing, pneumatic conveying, comminuting and classifying, wherein the gas temperature at the end of the pneumatic conveying is from 50 to 95° C.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising the steps of: •—processing an aqueous polymer gel from polymerization of a monomer solution or suspension, •—drying the aqueous polymer gel in a conveyer dryer, in particular in a forced air conveyer dryer, wherein •—the conveyer dryer has a circulating conveyer belt and the aqueous polymer gel is conveyed on the circulating conveyer belt, and wherein •—the circulating conveyer belt is formed as a circulating plate conveyer belt, comprising a number of belt plates separated by a hinge line of a hinge assembly and each belt plate having a surface for receiving the aqueous polymer gel, wherein said hinge assembly comprises a knuckle joint (301) with the hinge line in form of a straight hinge line.

Abstract: The invention relates to an apparatus for producing pulverulent poly(meth)acrylate, comprising a reactor for droplet polymerization having an apparatus for dropletization of a monomer solution for the preparation of the poly(meth)acrylate having holes through which the monomer solution is introduced, an addition point for a gas above the apparatus for dropletization, at least one gas withdrawal point on the circumference of the reactor, a fluidized bed and an apparatus for product discharge from the fluidized bed. The apparatus for product discharge comprises a discharge apparatus, with a backup segment (39) disposed above the discharge apparatus.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising the steps of: •—processing an aqueous polymer gel from polymerization of a monomer solution or suspension, •—drying the aqueous polymer gel in a conveyer dryer, in particular in a forced air conveyer dryer, wherein •—the conveyer dryer has a circulating conveyer belt and the aqueous polymer gel is conveyed on the circulating conveyer belt, and wherein •—the circulating conveyer belt is formed as a circulating plate conveyer belt, comprising a number of belt plates separated by a hinge line of a hinge assembly and each belt plate having a surface for receiving the aqueous polymer gel, wherein said hinge assembly comprises a knuckle joint (301) with the hinge line in form of a straight hinge line.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising the steps of: •—processing an aqueous polymer gel from polymerization of a monomer solution or suspension, •—drying the aqueous polymer gel in a conveyer dryer, in particular in a forced air conveyer dryer, wherein •—the conveyer dryer has a circulating conveyer belt and the aqueous polymer gel is conveyed on the circulating conveyer belt, and wherein •—the circulating conveyer belt is formed as a circulating plate conveyer belt, comprising a number of belt plates separated by a hinge line of a hinge assembly and each belt plate having a surface for receiving the aqueous polymer gel, wherein said hinge assembly comprises a knuckle joint (301) with the hinge line in form of a straight hinge line.

Abstract: A production process for production of water-absorbing polymer particles including drying an aqueous polymer gel in a belt drier with a conveyor belt. The belt drier is formed with a drier setup substantially comprising the conveyor belt and an air recycling conduit downstream of the drier setup for air recycling, where recycled air is withdrawn from the drier setup and fed back to the drier setup via the air recycling conduit.

Abstract: A production process for production of water absorbing polymer particles, including drying an aqueous polymer gel in a belt drier with a conveyor belt having a drier setup in the interior, in which drying air in the interior of the drier setup is conducted in countercurrent counter to the conveying direction and the interior of the drier setup is kept substantially at a reduced pressure relative to the ambient pressure outside the drier setup, and the interior has and/or forms a pressure zone, and is especially divided into a number of pressure zones.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising the steps of: —processing an aqueous polymer gel from polymerization of a monomer solution or suspension, —drying the aqueous polymer gel in a conveyer dryer, in particular in a forced air conveyer dryer, wherein —the conveyer dryer has a circulating conveyer belt and the aqueous polymer gel is conveyed on the circulating conveyer belt, and wherein —the circulating conveyer belt is formed as a circulating plate conveyer belt, comprising a number of belt plates separated by a hinge line of a hinge assembly and each belt plate having a surface for receiving the aqueous polymer gel, wherein said hinge assembly comprises a knuckle joint (301) with the hinge line in form of a straight hinge line.

Abstract: A process for thermal surface postcrosslinking of water-absorbing polymer particles, wherein the polymer particles are coated with an aqueous solution, the coated polymer particles are deagglomerated and the deagglomerated polymer particles are thermally surface postcrosslinked by means of a drum heat exchanger with an inverse screw helix.