Abstract: A belt drier arrangement for drying an aqueous polymer gel and for comminuting the dried polymer gel to give dried polymer particles, having: a belt drier having a drier setup and a conveyor belt for receiving and for drying the aqueous polymer gel to give a dry cake or fragments on a receiving surface of the conveyor belt, and a comminution arrangement, disposed downstream of the drier setup in product flow direction, for comminution of the dried polymer gel of the dry cake or fragments to give dried comminuted polymer particles. The comminution arrangement has a comminutor in the form of a milling drum which is disposed with an upper working line of a working edge of the milling drum at the level of or above a receiving surface of a conveyor belt, for mill processing of the dry cake or of the fragments, where the milling drum is designed to eject comminuted dried polymer particles of the dry cake or of the fragments in the downward direction.

Abstract: A belt drier arrangement for drying an aqueous polymer gel and for comminuting the dried polymer gel to give dried polymer particles, having: a belt drier having a drier setup and a conveyor belt for receiving and for drying the aqueous polymer gel to give a dry cake or fragments on a receiving surface of the conveyor belt, and a comminution arrangement, disposed downstream of the drier setup in product flow direction, for comminution of the dried polymer gel of the dry cake or fragments to give dried comminuted polymer particles. The comminution arrangement has a comminutor in the form of a milling drum which is disposed with an upper working line of a working edge of the milling drum at the level of or above a receiving surface of a conveyor belt, for mill processing of the dry cake or of the fragments, where the milling drum is designed to eject comminuted dried polymer particles of the dry cake or of the fragments in the downward direction.

Abstract: Superabsorbents are produced by polymerisation in a kneader equipped with at least two parallel shafts that also comprises elements on at least one shaft that transport the kneader's content parallel to the shafts from a feed section to a discharge section, the process comprising the addition of an inorganic powder to the kneader's contents prior to or during polymerisation and the addition of at least one other additive to the kneader's contents during polymerisation, wherein the inorganic powder is added no later than half the average residence time of the kneader's contents and the other additive is added no earlier than half this residence time.

Abstract: What is described is a process for producing water-absorbing resins, in which a) acrylic acid is prepared at an acrylic acid production site, b) the acrylic acid prepared is dissolved in water at the acrylic acid production site to obtain an aqueous acrylic acid solution, c) the aqueous acrylic acid solution is fed into a pipeline at the acrylic acid production site and passed through the pipeline to an acrylic acid processing site and d) the aqueous acrylic acid solution is subjected to a free-radical polymerization at the acrylic acid processing site. The process ensures safe transport of the highly reactive acrylic acid. Endangerment as a result of premature polymerization, as in the case of glacial acrylic acid, is ruled out, since the acrylic acid is “diluted” by the aqueous solvent and the specific heat capacity and the evaporation enthalpy of the water limit the maximum temperature rise.

Abstract: The invention relates to a method for the transportation of a monomer composition in which a composition comprising an aqueous solution of partially or entirely neutralized acrylic acid or overneutralized acrylic acid is placed in a transport means or sent through a pipe. The method according to the invention is characterized in that it has an increased level of safety during the transportation of acrylic acid monomers, an improved quality of the resulting product, and a high degree of efficiency. The method ensures safe transport of the highly reactive acrylic acid. The amount of polymerization inhibitors added to said acrylic acid may be reduced. An additional advantage is the minimization of the formation of dimeric acrylic acid. Tempering of containers, pipes, and pipelines may be omitted.