Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C11/00—Regeneration of pulp liquors or effluent waste waters
  • D21C11/12—Combustion of pulp liquors
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F5/00—Dryer section of machines for making continuous webs of paper
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
  • D21H25/04—Physical treatment, e.g. heating, irradiating
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21J—FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE
  • D21J1/00—Fibreboard

Definitions

• the invention relates to a device for guiding and / or deflecting and / or pressing and / or rolling up and / or finishing a process material in the production of paper, paperboard or cardboard or in a treatment whose properties change treatment.
• the invention also relates to a device for guiding and / or diverting and / or pressing and / or rolling up and / or finishing a process material in the production of paper, paperboard or cardboard or in the case of a property-altering treatment comprising one in contact with the process material coming roll.
• the invention relates to a process for the preparation or treatment of a process material in the manufacture or treatment of paper, cardboard or paperboard, preferably for operating a device according to the invention, wherein the process material with preferably non-thermal,etcflä ⁇ chigem plasma under atmospheric pressure brought into contact, the plasma generated in the immediate vicinity of the process material or in the process material or in its immediate environment a
• Gas discharge in particular a corona discharge, is generated under atmospheric pressure.
• the press area is followed by an area of finishing for the paper.
• the processing takes place either integrated into the papermaking plant or on a separate basis. guess facility.
• the finishing of paper often takes place in several successive process steps.
• the following quality properties are to be positively influenced by the treatment: - Optical properties such as smoothness, gloss, whiteness, Gleichmä ⁇ LIQUID and contrast of a printing result,
• a gentle drying of the paper such as infrared ⁇ drying and / or air drying.
• a treatment for improving the surface quality with non-thermal, "cold plasmas" is already known.
• the previous methods use this low-pressure plasma reactors, which are technically very complicated because of the necessary vacuum generation. Atmospheric printing processes, as they are needed in the paper industry to master the usual process speeds today, are not yet known.
• DE 19 836 669 A1 discloses a process for surface pretreatment on solid paper after completed sheet formation.
• the object of the invention is to provide an apparatus and a method for further increasing the paper quality in papermaking.
• the device-related object is achieved by at least two electrodes for generating a plasma in the process material or in its immediate vicinity, wherein the two electrodes are arranged on opposite sides of the process material.
• the object is achieved by the second device mentioned above in that the roller is prepared as a first electrode, wherein in the process material or in its immediate vicinity, a plasma can be generated.
• a second electrode is arranged relative to the roller such that the process material can be transported or guided between the roller, in particular the first electrode, and the second electrode.
• the paper or Pro ⁇ can advantageously zessgut between the roller which is directed as a first electrode Herge ⁇ , and the second electrode are treated with plasma.
• the roller is arranged such that it, preferably with the process material, preferably a sheet formed before ⁇ a gepress- th sheet, especially a paper web comes into contact.
• the process material preferably a sheet formed before ⁇ a gepress- th sheet, especially a paper web comes into contact.
• the roller in the device according to the invention as an electrode is arranged, the lau ⁇ about their Fende process material may be treated with plasma.
• Even existing older refining plants can be beneficial be upgraded by replacing the device according to the invention against the conventional transport rollers, and thus provide the paper with an increased quality.
• a second roller wherein the second Wal ⁇ ze is such arranged relative to the roller, that a GES flächi ⁇ process material, in particular the paper web on both sides comes into contact with the rollers. If the paper is guided quasi slalom-like by means of various transport rollers through a finishing machine, it is advantageous in the sense of an effective treatment to arrange the rolls designed as electrodes one behind the other in such a way that the paper can be effectively treated successively with plasma from both sides.
• roller is prepared with a gas pressläs ⁇ sigen surface.
• the roll is adapted to radially supply a gas stream.
• a gas stream preferably finely divided air bubbles or oxygen or oxygen are mixed with a carrier gas, e.g. Argon, which has flowed into the roller, which in turn can penetrate through the gas-permeable surface into the paper.
• a carrier gas e.g. Argon
• the device can be configured with a means for flowing the process material with a gas stream.
• Gas flow is directed by utilizing the advantages already mentioned directly into the treatment room, ie passed between the two electrodes.
• the electrodes or said rollers generate the plasma in a particularly advantageous manner by a high voltage pulse generator ⁇ communicating with the or the electrode is connected.
• the plasma or a pulsed corona discharge directly above and / or below the paper may be implemented using a very short high voltage pulses by little as 10 microseconds, insbeson ⁇ particular 1 s, and particularly advantageously significantly less than 1 s to voltages of a few kV to above 100 kV, be produced depending on the distance of the electrodes and the properties of the paper in an advantageous manner.
• It is of particular advantage that has or with a simultaneous or nearly simultaneous two-sided treatment of the process material with plasma or a gas- ⁇ charge which, among other things, a surface-altering We ⁇ kung turn engages in the molecular structure of the process material that the process material homogeneously is changed.
• the ⁇ be indicated that any possible inhomogeneities or stress conditions are avoided in the process material.
• a still unpressed and / or moist sheet or dry sheet is used in a paper or board production process as process material.
• high-voltage pulses with a duration of less than 10 ⁇ s are preferably generated.
• RF radio frequency
• Radicals are generated in gas discharges by high-energy electrons collide with molecules and thereby dissociate or excite them and thus lead to radical formation. In the dissociation, radicals are released immediately, while the excitation by subsequent radiant transitions UV light is generated, which in turn reacts with and preferably dissociates air and water molecules.
• Streamer are discharge channels that are under construction and form due to the applied high external field strengths. An assembly of such streamer takes place within less than 10 ns and then rapidly merges into a thermal breakdown channel.
• the pulse duration is significantly shorter than corresponds to a build-up time of a complete breakdown in the respective medium.
• the paper web or the process material located between the electrodes used for the streamer discharge this is particularly advantageous since the paper or the process material as ⁇ acts by partially as a dielectric barrier.
• the dielectric barrier makes it easier to control the transition from the streamer to the breakdown.
• FIG 1 shows a schematic representation of a Toiletherstel ⁇ treatment plant with a screening device, a press device according to the invention and a finishing and / or drying plant
• FIG 2 is a view (sectional) of an arrangement for generation of free radicals in corona plasmas in pulp or air: parallel plate
• FIG 3 shows a schematic representation of pulses for generating radicals in corona discharges in air or aqueous media when using short (typically less than 1 ⁇ s) high voltage pulses with high pulse repetition rate
• FIG. 11 shows a device according to the invention with a roller as a transport roller.
• the papermaking plant 1 shows a schematic representation of a paper production plant 1, as it is set in present-day paper mills turned ⁇ . Their construction and the combination of different aggregates are determined by the type of paper, board and paperboard types to be produced, as well as the raw materials used.
• the papermaking plant 1 has a spatial extent of about 10 m in width and about 120 m in length. It takes only a few seconds from the first impact of a fiber suspension or pulp 39 on a screening device 9 to the finished paper 27, which is finally rolled up in a reel 15. The entire papermaking process is essentially subdivided into the areas of stock preparation, paper machine, finishing and equipment.
• a headbox 7 of the papermaking plant 1 distributes the pulp suspension uniformly over the entire sieve ⁇ width.
• the paper web 27 still contains about 80% water.
• Another dewatering process is carried out by mechanical pressure in the press device 11.
• the paper web 27 is passed between rollers made of steel and thereby dewatered.
• the press device 11 is followed by a drying system 13.
• the remaining residual water is evaporated in the drying plant 13.
• Slalom-like, the paper web 27 passes through several steam-heated drying cylinders. In the end, the paper 27 has a residual moisture of a few percent.
• resulting water vapor ist ⁇ is sucked and guided in a non-illustrated zones assert forungsanla ⁇ ge.
• Paper web 27 a large-scale plasma can be generated under atmospheric pressure in the immediate vicinity of the paper web 27, the electrodes 47 and 48 are connected to a high voltage ⁇ pulse generator 46.
• a high-voltage pulse generator 46 By means of this high-voltage pulse generator 46, a large-volume plasma with a large cross section and with a high power density is generated between the electrodes 47 and 48.
• the large-volume plasma with high power density is produced by means of the arrangement OF INVENTION ⁇ to the invention in that a DC corona discharge intense, short duration high voltage pulses are superimposed with a high pulse repetition rate of 1 kHz. In this mode of operation, a highly homogeneous, large-volume plasma with a high power density is produced without the plasma constrictions that are known in DC corona discharges.
• the first electrode 47 in the press apparatus 11 is designed as a semicircular grid electrode. By schrun ⁇ de configuration of the electrode 47 can follow the paper web over the course of the sprocket 12th
• the second electrode 48 in the press apparatus 11 is configured as a plate electrode and arranged such that the transport roller 12 is guided between the electrodes 47 and 48.
• the crimping process compresses the paper structure, the strength is further increased and the surface quality is influenced DEND ⁇ decisive. Furthermore, the treatment of the pressed paper 27 with cold plasma, in particular with generated radicals, further changes the molecular structure of the paper surface. In addition to increasing the strength of the paper 27, a later printability is improved.
• a streamer is a special form of a linearly moving plasma cloud or a developing discharge channel that forms due to the excited high external field strength. An assembly of such streamer takes place within less than 10 ns and merges very quickly into a thermal breakdown channel.
• Aforesaid Anord ⁇ voltage of the electrode system, wherein the paper web's 27 Zvi ⁇ the electrodes used for the streamer discharge located, is particularly advantageous since the paper 27 thereby partially acts as a dielectric barrier, thus the transition can be suppressed from the streamer to the punch ,
• By direct treatment of the paper web 27 with the cold plasma of the paper web are in the immediate area 27 is preferably the radical O 3, H 2, O 2, OH, HO 2 and HO 2 generates "In addition to an increase in strength, these radicals solve a.
• the high clamping ⁇ voltage pulse generator 46 is operated such that it microseconds generates voltage pulses with a duration of typically 1 between the electrodes 47 and 48. a for the generation of free radicals and ozone in the paper web and in the immediate vicinity of the paper web The high voltage pulses are superimposed on the DC voltage to form a total amplitude of a few 100 kV.
• FIG. 2 shows, as a further exemplary embodiment, a sectional representation of an arrangement for generating radicals.
• a high voltage electrode 50 is arranged ⁇ .
• the outer jacket of the arrangement is prepared as a counter ⁇ electrode 51.
• ei ⁇ ne to be screened pulp fiber suspension 39.
• a streamer 53 shown between the electrodes 50 and 51. Radicals are generated in streamers by being high-energy
• the applied voltage waveform of the high tensioning ⁇ shown voltage pulses.
• the abscissa shows the time in milliseconds and the ordinate the voltage in kV. The units are chosen arbitrarily.
• One Level of typically about 100 kV DC voltage coincides with the illustrated abscissa.
• the illustrated pulse voltage is thus superimposed on the DC voltage.
• the pulses 66 and 67 have a pulse width 62 of less than 1 microseconds, wherein the individual pulses 66, 67 have a steeply rising edge with a rise time 64 and a less steeply sloping edge.
• the pulse repetition time is typically between 10 ⁇ s and 100 ms.
• the individual pulses 66, 67 have such a total ⁇ amplitude, which is above the predetermined DC voltage ei ⁇ ne predetermined energy density is achieved.
• the pulse rise time 64 while short compared to Pulsab ⁇ falling time. Through such kind of pulses is achieved that electric breakdowns to spatial and the zeitli ⁇ chen interference would result in the homogeneous plasma density distribution, are avoided.
• FIGS. 4 to 9 show examples of electrode systems for generating corona discharges in preferably aqueous media.
• FIG. 4 shows a plate-and-plate arrangement of a first plate 70a as an electrode and a second plate 70b as an electrode.
• the first plate 70a and the two ⁇ te plate 70b are arranged parallel to each other.
• the first plate 70a forms the high voltage electrode and is connected to the high voltage pulse generator 46 via a high voltage cable.
• the second plate 70b forms the counter electrode, and is available as a ground electrode to the high voltage pulse generator 46 in ⁇ compound.
• FIG. 5 A corresponding arrangement with specially flat plate ⁇ electrodes is shown in FIG 5. Again there are two solid plate electrodes 70a and 70c at a fixed distance with a high voltage electrode 71 in the middle.
• the high voltage electrode 71 is made as a solid wire and connected to the high voltage output of the high voltage pulse generator 46 connected.
• the grounded plates 70a, 70c are also in communication with the high voltage pulse generator.
• FIG. 6 shows a wire-tube arrangement as an electrode system.
• a cylindrical electrode 72 projects centrally a high ⁇ voltage electrode 71 inside.
• bias electrode 71 constructed as a solid wire and connected to the high voltage pulse generator 46 in Fig. 5
• the cylindrical electrode 72 which preferably is a wire mesh as designed is grounded and is connected to the high tension voltage pulse generator 46 in ⁇ compound.
• FIG. 7 shows a tip-plate arrangement as Elektrodensys ⁇ tem.
• Three tips 73 are connected to the high voltage pulse generator 46 via a high voltage line.
• the tips 73 are arranged at right angles to a grounded plate electrode 74.
• the distance of the tip electrodes 73 to the plate electrode 74 is adjustable and thus can be adapted for different process conditions.
• FIG. 8 shows an electrode system arrangement comprising 3 plates 70a, 70d and 70e.
• the first plate 70a which is connected as a high-voltage electrode to the high-voltage pulse generator 46, is arranged centrally between two solid plates 70d and 70e.
• the plates 70a and 70b are connected via ei ⁇ nen plate connector 70f. Since the plate 70d as a grounded counter electrode is in communication with the high voltage pulse generator 46, the plate 70e above the plate connector 70f also functions as a grounded counter electrode.
• FIG. 9 shows an electrode system as a grid-grid arrangement.
• a first grid 75a and a second grid 75b are parallel here.
• the first grid 75a forms the high voltage electrode and is connected to the high voltage pulse generator 46.
• the second grid 75b forms the grounded counter electrode and communicates with the high voltage pulse generator 46.
• a hybrid discharge, wherein one electrode fully ⁇ constantly suspension fiber is 75a outside of a to be treated 39 and a second electrode 75b fully or partially in the fiber suspension is immersed 39 is a alter- tive arrangement in which the screen is designed as an electrode 75a.
• the screen is designed as a Gitterelekt ⁇ rode and forms the high voltage electrode, which communicates with the high voltage pulse generator 46 in connection.
• the grounded counter electrode 76 b is designed as a grid electrode and is connected to the Hochwoodsimpulsge ⁇ generator 46 in conjunction.
• a Hochwoodselekt ⁇ rode comprising a plurality of electrically interconnected rod electrodes is disposed in the near-surface gas space of the fiber suspension 39 or the paper such that their rods are parallel to the surface.
• a grounded counter electrode is designed as a solid plate and arranged in distributed over the entire surface equidistant distances from the high voltage electrode.
• FIG. 10 the schematic press device 11 known from FIG. 1 is enlarged and shown in greater detail.
• the Pa ⁇ pier 27 is passed over several rollers and rolls through the press device 11 while sert increasingly enticas ⁇ and compacted.
• the press device 11 is not discussed in more detail, since the skilled person a press device without the invention
• Electrode arrangement is known. Immediately after an entry area for the paper 27 into the press apparatus, the electrodes 47 and 48, which form a plasma reactor within the press apparatus 11, are arranged. The electrodes 47 and 48 are connected to the high voltage pulse generator 46. By means of the electrodes 47, 48 and the high-voltage pulse generator 46, a plasma is generated between the electrodes 47, 48 as already described above.
• the paper track 27 extends between the electrodes 47,48 and is treated on both sides with plasma.
• the Pa ⁇ forms pierbahn 27 a previously described dielectric barrier and can thus favor the Stream Erbil extension.
• the electrode 12a is configured as a Rollenelekt ⁇ rode, similar to the roller electrode in FIG 11.
• the paper 27 is guided by the roller electrode 12a.
• a plasma for the treatment of the paper 27 is generated by means of the high-voltage generator 46 connected to them.
• the transport roller 12, the grounded counter electrode 12a Force and form fit, the paper 27 is guided by the transport roller 12.
• a likewise grounded counter electrode 12c which follows the course of the semicircular feed roller 12 is, roll in a not shown way with the transport ⁇ 12, in particular with the roller electrode 12, elekt ⁇ driven connected.
• an electrode arrangement is formed with a constant spacing, in which the individual wires 12b to 12b n are arranged centrally.
• the grounded electrode 12a passes over the feed roller 12 to the bear ⁇ beitende paper 27, and thus each of the arranged between the two electrodes 12a and 12c wires 12b to 12b n with plasma and / or pressurized gas discharges.
• the arrangement is also referred to as a curved wire-plate arrangement which forms a plasma reactor.

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• 2005
  • 2005-10-24 DE DE102005050845A patent/DE102005050845A1/de not_active Withdrawn
• 2006
  • 2006-06-08 DE DE502006005412T patent/DE502006005412D1/de active Active
  • 2006-06-08 EP EP06763592A patent/EP1893809B1/fr not_active Not-in-force
  • 2006-06-08 WO PCT/EP2006/063021 patent/WO2006134067A2/fr not_active Application Discontinuation
  • 2006-06-08 AT AT06763592T patent/ATE449211T1/de active

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