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 a heat exchanger for heating gas to a temperature in the range from 150 to 400° C., wherein the gas is heated by indirect heat transfer and all the surfaces of the walls of the heat exchanger which come into contact with the gas have been hot dip galvanized and the surfaces which come into contact with the gas, after the hot dip galvanization, have been heat treated at a temperature in the range from 400 to 750° C. The invention further relates to the use of the heat exchanger.

Abstract: The invention relates to a fluidizing plate, comprising a supporting structure and plate segments, the plate segments respectively having openings through which gas flows during operation. The plate segments are respectively releasably connected to the supporting structure and two neighboring plate segments respectively overlap and are releasably connected to one another in the region of the overlap. The invention also relates to an apparatus with such a fluidizing plate.

Abstract: A method for the classification of superabsorber particles is disclosed, in which the superabsorber particles are put onto a top screen deck of a screening machine having at least two screen decks with a different hole size, the superabsorber particles which are smaller than the holes of the respective screen deck respectively falling through the holes and the superabsorber particles remaining on the screen deck being removed via an extraction point. Balls are positioned on each perforated plate, which balls are propelled upward by the movement of the perforated plate and strike from below the screen deck respectively lying above, wherein the balls have a stiffness in the range from 40 to 100 N/mm and a damping in the range from 1 to 4%. A machine for carrying out the method also is disclosed.

Abstract: The invention relates to a device (14) and to a method for the contactless detection of a torque of a shaft (10) and/or torsional natural frequencies and/or torsional oscillations. The shaft (10) contains a ferromagnetic material. A measurement head (16) facing toward a shaft wall (12) comprises an excitation coil (22) which couples a magnetic field into the shaft (10). The measurement head (16) furthermore contains a number of measurement coils (24, 26, 28, 30), which measure the magnetic field emerging from the shaft (10).

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 method for connecting functional elements (14) to a shaft (10, having the following steps: (a) forming elevations (12) for receiving the functional elements (14), said elevations (12) being machined out of the shaft (10) by removing material, and (b) welding the functional elements (14) to the elevations (12) on the shaft (10).

Abstract: The invention relates to a fluidizing plate, comprising a supporting structure and plate segments, the plate segments respectively having openings through which gas flows during operation. The plate segments are respectively releasably connected to the supporting structure and two neighboring plate segments respectively overlap and are releasably connected to one another in the region of the overlap. The invention also relates to an apparatus with such a fluidizing plate.

Abstract: A method for connecting functional elements (14) to a shaft (10, having the following steps: (a) forming elevations (12) for receiving the functional elements (14), said elevations (12) being machined out of the shaft (10) by removing material, and (b) welding the functional elements (14) to the elevations (12) on the shaft (10).

Abstract: A method for detecting damage to a hollow shaft is disclosed. A sensor for transmitting and receiving a signal is positioned at an end face of the hollow shaft, a signal is transmitted and an echo of the signal is received, the signal propagation time from the time of transmitting the signal until receiving the echo is determined, and the signal propagation time is compared to a predetermined intended value, and with a warning being emitted in the case of a deviation.

Abstract: The invention relates to a heat exchanger for heating gas to a temperature in the range from 150 to 400° C., wherein the gas is heated by indirect heat transfer and all the surfaces of the walls of the heat exchanger which come into contact with the gas have been hot dip galvanized and the surfaces which come into contact with the gas, after the hot dip galvanization, have been heat treated at a temperature in the range from 400 to 750° C. The invention further relates to the use of the heat exchanger.

Abstract: The invention relates to a device (14) and to a method for the contactless detection of a torque of a shaft (10) and/or torsional natural frequencies and/or torsional oscillations. The shaft (10) contains a ferromagnetic material. A measurement head (16) facing toward a shaft wall (12) comprises an excitation coil (22) which couples a magnetic field into the shaft (10). The measurement head (16) furthermore contains a number of measurement coils (24, 26, 28, 30), which measure the magnetic field emerging from the shaft (10).

Abstract: A method for the classification of superabsorber particles is disclosed, in which the superabsorber particles are put onto a top screen deck of a screening machine having at least two screen decks with a different hole size, the superabsorber particles which are smaller than the holes of the respective screen deck respectively falling through the holes and the superabsorber particles remaining on the screen deck being removed via an extraction point. Balls are positioned on each perforated plate, which balls are propelled upward by the movement of the perforated plate and strike from below the screen deck respectively lying above, wherein the balls have a stiffness in the range from 40 to 100 N/mm and a damping in the range from 1 to 4%. A machine for carrying out the method also is disclosed.

Abstract: A method is described for operating machines (10) having moving parts and arranged jointly on a support (32), said parts being moved periodically with substantially the same frequency, and wherein the phase of an oscillation of one machine (10) in relation to the phase of an oscillation of a further machine (10) is controlled by shifting the phases with respect to one another such that the amplitude of an oscillation of a structural part, for example of the support (32), remains below a predefined maximum value.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising polymerization, drying the resulting polymer gel on a through circulation belt dryer, crushing the dried polymer gel, pre-grinding, separating of incompletely dried particles with a perforated plate, grinding and classifying the resulting polymer particles.

Abstract: A method for operating an apparatus with at least one rotating shaft, the at least one rotating shaft comprising functional elements which act on material to be processed in the apparatus, the apparatus comprising a filling orifice and an outlet orifice with an adjustable lower edge, and material being conveyed continuously through the apparatus from the filling orifice to the outlet orifice, said method comprising the following steps: a) measuring load data for the at least one rotating shaft in order to determine shaft load, b) lowering the lower edge of the outlet orifice and/or reducing the quantity of material supplied if the shaft load exceeds a specified maximum load, or displacing the lower edge of the outlet orifice upwards and/or increasing the quantity of material supplied if the shaft load is less than a specified shaft load.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising polymerization and drying the resulting polymer gel on a through-circulation belt dryer having at the end of the belt in transport direction a means for guiding the dried polymer gel down towards a means for crushing the dried polymer gel.

Abstract: A method is described for operating machines (10) having moving parts and arranged jointly on a support (32), said parts being moved periodically with substantially the same frequency, and wherein the phase of an oscillation of one machine (10) in relation to the phase of an oscillation of a further machine (10) is controlled by shifting the phases with respect to one another such that the amplitude of an oscillation of a structural part, for example of the support (32), remains below a predefined maximum value.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising polymerization and drying the resulting polymer gel on a through-circulation belt dryer having at the end of the belt in transport direction a means for guiding the dried polymer gel down towards a means for crushing the dried polymer gel.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising thermal postcrosslinking in a contact dryer having external heated outer surfaces.