Abstract: A machine for dewatering and drying a paper, cardboard or other fibrous web, to which machine a fibrous stock suspension is fed which is formed at least partially from waste paper. The machine includes at least two press nips which are formed in each case by two press rolls, wherein a fibrous web runs through first press nip with a water absorbing dewatering belt on both sides. The fibrous web then runs through a second press nip with at least one other dewatering belt and a smooth impermeable transfer belt on both sides. A transfer belt transfers the fibrous web after second press nip to a belt in a downstream machine unit, e.g. dryer group. The dryer group allows the fibrous web to be guided in a serpentine manner alternatively over heated dryer cylinders and vacuum equipped guide rolls.

Abstract: The invention relates to a press for a machine for producing a fibrous material web, including at least one press nip formed between a press roller and a counter press roller of the press for guiding through the fibrous material web in a dehydrating manner, and two band shaped covers, which are each guided by multiple guide rollers in continuous circulation, so as to run together through the press nip, so that the fibrous material web is guided through sandwiched between said covers, and then separated again at a separation point, in order to continue guiding the fibrous material web on the one cover and separate it from the other cover. One guide roller of the guide rollers arranged at the separation point is a suctioned guide roller of the one cover, to hold the fibrous material web on the one cover at the separation position.

Abstract: A machine for dewatering and drying a paper, cardboard or other fibrous web, to which machine a fibrous stock suspension is fed which is formed at least partially from waste paper. The machine includes at least two press nips which are formed in each case by two press rolls, wherein a fibrous web runs through first press nip with a water absorbing dewatering belt on both sides. The fibrous web then runs through a second press nip with at least one other dewatering belt and a smooth impermeable transfer belt on both sides. A transfer belt transfers the fibrous web after second press nip to a belt in a downstream machine unit, e.g. dryer group. The dryer group allows the fibrous web to be guided in a serpentine manner alternatively over heated dryer cylinders and vacuum equipped guide rolls.

Abstract: The invention relates to a press for a machine for producing a fibrous material web, including at least one press nip formed between a press roller and a counter press roller of the press for guiding through the fibrous material web in a dehydrating manner, and two band shaped covers, which are each guided by multiple guide rollers in continuous circulation, so as to run together through the press nip, so that the fibrous material web is guided through sandwiched between said covers, and then separated again at a separation point, in order to continue guiding the fibrous material web on the one cover and separate it from the other cover. One guide roller of the guide rollers arranged at the separation point is a suctioned guide roller of the one cover, to hold the fibrous material web on the one cover at the separation position.

Abstract: The present invention relates to compositions and methods for the synthesis of 18F labeled compounds. In particular, the present invention relates to a copper (I) mediated one pot method for 18F-trifluoromethylation of aromatic- or heteroaromatic halides with difluoro(iodo)methane (e.g., for use at PET imaging agents).

Abstract: A method for operating a sheet-forming unit of a papermaking machine. At least one fibrous material suspension is fed to a headbox and is conducted in a plurality of turbulence-generating channels to form sub-flows, and fed to a nozzle. From the nozzle, the at least one fibrous material suspension is in the form of a free jet into the forming unit to define an impingement line. In a final fluidization region of an individual turbulence-generating channel a pressure loss (?p) of ?50 mbar is generated within the fibrous material suspension before inlet thereof into the nozzle, and the fibrous material suspension is guided from the final fluidization region as far as the impingement line in such a way that the dwell time of the suspension in the region defined by the final fluidization region as far as the impingement line ranges from >30 ms to ?300 ms.

Abstract: The invention relates to a method for optimizing the energy balance of a forming section in a machine for producing fibrous webs, in which a fiber suspension, which is fed to the forming section by way of a material ramp after the immobility point is reached, is passed through at least two dewatering units within a compression zone and to a subsequent functional unit. The invention is characterized in that a setpoint value for a target dryness to be set is predefined based on the existing dewatering elements as a function of a theoretical maximum achievable dryness under plant conditions in the area of the transition zone, said setpoint being selected such that it is less than the theoretical maximum achievable dryness but is equal to or greater than a required minimum dryness in the area of the transition zone, and that the target dryness is controlled by lowering the inlet dryness at one of the last dewatering units disposed in the direction of passage of the fiber suspension within the compression zone.

Abstract: A forming section in a machine for producing a web of fibrous material includes a control and/or regulating system including a control and/or regulating device which is connected with at least one device for at least indirect acquisition of one value at least indirectly characterizing the dry content of the fibrous web in a transfer area from the forming section to a following function unit, with a device for input of a desired value for the target dry content, and with at least the control elements of an individual dewatering unit located prior to one of the last dewatering units, or the last dewatering unit inside the compression zone. The control and/or regulating device also includes a device for creating the control variables for controlling the individual dewatering units.

Abstract: A method for operating a sheet-forming unit of a papermaking machine. At least one fibrous material suspension is fed to a headbox and is conducted in a plurality of turbulence-generating channels to form sub-flows, and fed to a nozzle. From the nozzle, the at least one fibrous material suspension is in the form of a free jet into the forming unit to define an impingement line. In a final fluidization region of an individual turbulence-generating channel a pressure loss (?p) of ?50 mbar is generated within the fibrous material suspension before inlet thereof into the nozzle, and the fibrous material suspension is guided from the final fluidization region as far as the impingement line in such a way that the dwell time of the suspension in the region defined by the final fluidization region as far as the impingement line ranges from >30 ms to ?300 ms.

Abstract: A forming section in a machine for producing a web of fibrous material includes a control and/or regulating system including a control and/or regulating device which is connected with at least one device for at least indirect acquisition of one value at least indirectly characterizing the dry content of the fibrous web in a transfer area from the forming section to a following function unit, with a device for input of a desired value for the target dry content, and with at least the control elements of an individual dewatering unit located prior to one of the last dewatering units, or the last dewatering unit inside the compression zone. The control and/or regulating device also includes a device for creating the control variables for controlling the individual dewatering units.

Abstract: The invention relates to a method for optimizing the energy balance of a forming section in a machine for producing fibrous webs, in which a fiber suspension, which is fed to the forming section by way of a material ramp after the immobility point is reached, is passed through at least two dewatering units within a compression zone and to a subsequent functional unit. The invention is characterized in that a setpoint value for a target dryness to be set is predefined based on the existing dewatering elements as a function of a theoretical maximum achievable dryness under plant conditions in the area of the transition zone, said setpoint being selected such that it is less than the theoretical maximum achievable dryness but is equal to or greater than a required minimum dryness in the area of the transition zone, and that the target dryness is controlled by lowering the inlet dryness at one of the last dewatering units disposed in the direction of passage of the fiber suspension within the compression zone.

Abstract: A reactor for testing catalyst systems which has a plurality of catalyst tubes (2) which are arranged parallel to one another in the interior space of the reactor and whose ends are welded into tube plates and also has caps (3) at each end of the reactor which each bound a cap space (4), with a fluid reaction medium (5) being fed via one cap space (4) into the catalyst tubes (2), flowing through the catalyst tubes (2) and being discharged via the other cap space (4), and is also provided with a heat exchange medium circuit in which the heat exchange medium (6) is fed in at one end of the reactor, flows through the intermediate space between the catalyst tubes (2) and flows out at the other end of the reactor, wherein the catalyst tubes (2) are arranged in two or more catalyst tube regions (7) which are thermally separate from one another, is proposed.

Abstract: The invention relates to a pump (1) having a pump guide tube (13) for the transport of a heat-exchange medium (6) for a reactor having a bundle of catalyst tubes (2), where the pump (1) has a casing (14) which surrounds the pump guide tube (13), having an aperture (15) in the lower part of the casing (14) via which the heat-exchange medium (6) discharged from the lower region of the reactor by means of the pump (1) flows into the casing (14), flows upward in the region between the inner wall of the casing (14) and the outer wall of the pump guide tube (13), if desired via a heat exchanger (18), flows into the interior of the pump guide tube (13) via an aperture (16) in the upper region of the pump guide tube (13), flows through the pump guide tube (13) from top to bottom and flows via an aperture (17) in the lower region of the pump guide tube (13) into the reactor, into the upper region of the interspace between the catalyst tubes (2).

Abstract: Process for conditioning a circulating felt belt of a machine, pipe suction apparatus and traversing pipe suction apparatus therefor, the process including performing a zonal conditioning of a plurality of zones across a width of the felt belt by measuring at least one of, fibrous material web cross direction profile; felt belt cross direction profile; and permeability of the felt belt across the width of at least one of the web and the belt. The felt belt is conditioned depending on measuring results obtained for a respective zone. The pipe suction apparatus includes a ceramic body extending at least essentially across the entire width of the felt belt, the ceramic body being provided with a slotted surface by way of which the felt belt is subjectable to vacuum, with a respective effective amount of slotted surface being zonally variably adjustable by way of movable tongues.

Abstract: Process for determining disturbances of a moisture cross profile of a fibrous material web in a paper making machine, a paper making machine, and a measuring arrangement for measuring the disturbances, the process including guiding the fibrous material web by way of at least one water-permeable belt and collecting and draining off water released from the belt. The water is collected by several sections separated from one another. The process further includes measuring per time unit, the amount of water in each section, wherein the sections extend at right angles to a web running direction over only a partial section of the fibrous material web. The paper making machine includes at least one water-permeable belt, the belt being wrapped around a roll. The measuring arrangement includes a water collection device having the form of one of a trough or channel.

Abstract: On-spec phthalic anhydride is prepared by distillative purification of crude phthalic anhydride by a process in which crude phthalic anhydride is fed to a distillation column which is operated at reduced pressure, the low boilers are removed at the top or in the vicinity of the top of the distillation column and the on-spec phthalic anhydride is removed from the column via a side take-off.

Abstract: A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.

Abstract: In a process for isolating &agr;-ethynyl carbinols from the liquid reaction mixture from the addition of acetylene onto &agr;,&bgr;-unsaturated carbonyl compounds by distillation, the distillation is carried out continuously, the feed stream is introduced into the middle section of a distillation column (K), the major part of the water is distilled off azeotropically together with the solvent at the top of the column, and the &agr;-ethynyl carbinol target product is taken off below the feed point to the column.

Abstract: A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.

Abstract: Copolymer comprising ethylene units and vinyl formate units, the content of free vinyl formate in the polymer preferably being not more than 5000 ppm, based on the weight of the copolymer, a process for its preparation, and its use as flow improver, especially in petroleum distillates, preferably fuel and propellant compositions, especially petroleum middle distillates, and also a fuel and propellant composition comprising a principal quantity of a fuel and propellant and that quantity of a copolymer as above which is effective in improving the flow properties.