US20020007927A1 - Method and equipment for regulation of the initial part of the dryer section in a paper machine - Google Patents
Method and equipment for regulation of the initial part of the dryer section in a paper machine Download PDFInfo
- Publication number
- US20020007927A1 US20020007927A1 US09/867,925 US86792501A US2002007927A1 US 20020007927 A1 US20020007927 A1 US 20020007927A1 US 86792501 A US86792501 A US 86792501A US 2002007927 A1 US2002007927 A1 US 2002007927A1
- Authority
- US
- United States
- Prior art keywords
- drying cylinders
- web
- drying
- cylinders
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
- D21F5/02—Drying on cylinders
- D21F5/04—Drying on cylinders on two or more drying cylinders
-
- 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
- D21F5/02—Drying on cylinders
- D21F5/06—Regulating temperature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S162/00—Paper making and fiber liberation
- Y10S162/09—Uses for paper making sludge
- Y10S162/10—Computer control of paper making variables
Definitions
- the invention concerns a method for regulation of the initial part of the dryer section in a paper machine, in which method moisture is removed from the paper web in the dryer section and in which method the paper web is dried in the dryer section, in which method the paper web to be dried is passed from the press section into the dryer section into the first group of drying cylinders, in which the paper web is dried against heated faces of drying cylinders.
- the invention concerns an equipment for regulation of the initial part of the dryer section in a paper machine, which equipment has been fitted in connection with the press section and with the dryer section in the paper machine.
- twin-wire draw and/or single-wire draw is/are employed.
- twin-wire draw the groups of drying cylinders comprise two wires, which press the web, one from above and the other one from below, against heated cylinder faces.
- twin-wire draw between the rows of drying cylinders, which are usually horizontal rows, the web has free and unsupported draws, which are susceptible of fluttering, which may cause web breaks, in particular in the stages of drying in which the web is still relatively moist and, therefore, of low strength.
- each group of drying cylinders comprises just one drying wire, on whose support the web runs through the whole group so that the drying wire presses the web on the drying cylinders against heated cylinder faces, and on the reversing cylinders or rolls placed between the drying cylinders the web remains at the side of the outside curve.
- the drying cylinders are placed outside the wire loop and the reversing cylinders or rolls inside the loop.
- steam is passed into their interior, and the temperature of the surface of a heated drying cylinder is regulated so that the pressure of the steam present in the interior of the cylinder is regulated.
- the first drying cylinders placed in the beginning of the dryer section are highly important. If the temperatures of the first drying cylinders are too high, the paper web has a tendency to follow the face of the cylinder, which causes problems of runnability and thereby restricts the running speed. Likewise, the brightness of the paper web becomes lower, the porosity increases, the roughness increases, formation of dust increases, and the bulk may become lower. On the other hand, if the temperatures of the first drying cylinders are too low, the drying cylinders in the initial part of the dryer section are inefficient.
- Important factors which affect the temperatures of the first cylinders in a dryer section include, among other things, the paper grade to be produced, the web moisture after the press section, and the temperature of the paper web. Usually, information on these factors in combination with the steam pressures in the first drying cylinders employed in cylinder drying has been obtained empirically only.
- the object of the present invention is to provide a solution for the problems described above.
- the method in accordance with the invention is mainly characterized in that, in the method, the surface temperatures of the first drying cylinders in the dryer section are measured, that, in the method, the dry solids content/moisture content of the paper web and the temperature of the paper web before said first drying cylinders are measured, and that, in the method, in view of producing the desired running situation, based on the measurement results obtained, the surface temperatures of said first drying cylinders and/or the dry solids content/moisture content and/or the temperature of the paper web before said first drying cylinders is/are regulated.
- the dryer section in accordance with the invention is mainly characterized in that the equipment comprises measurement devices fitted in connection with the first drying cylinders in the dryer section for measurement of the surface temperatures of said first drying cylinders, a measurement device for measurement of the dry solids content/moisture content of the paper web and of the temperature of the paper web before said first drying cylinders, and a control device for regulation of the surface temperatures of said first drying cylinders and/or of the dry solids content/moisture content and/or of the temperature of the paper web before said first drying cylinders, based on the measurement results obtained by means of the measurement devices, to produce the desired running situation.
- the surface temperatures of the first drying cylinders in the dryer section and the dry solids / moisture content of the paper web and the temperature of the web before the first drying cylinders are measured, and on the basis of the measurement results the surface temperatures of the first drying cylinders are regulated to the desired level so that a good running situation is achieved.
- the surface temperatures of the first drying cylinders can, of course, also be regulated by means of other known methods, for example by means of induction heating or by means of electrical resistors.
- the web temperature has two factors which act in opposite directions. On one hand, it has been noticed that, when the web is hotter, it does not adhere to the first hot faces equally well. On the other hand, the web strength becomes lower when the temperature becomes higher.
- the machine speed does not have a direct intensive effect on the adhering of the web to the first cylinder, but, on the other hand, it produces a vacuum in the opening web-cylinder gap, as a result of which vacuum the web tends to follow the cylinder face. This diverts the web from the face of the support wire and, thus, subjects the web to centrifugal forces which are increased in direct proportion to the second power of the speed.
- the web moisture has a great negative effect on the runnability of the initial part of the dryer section.
- a moist web has an intensive tendency to adhere to a cylinder face. In practice, this has caused, e.g., formation of dust and a so-called Tinting effect.
- the web strength becomes lower when the moisture content becomes higher.
- a solution is included in the scope of the present invention in which a regulation model has been formed by using at least some of the parameters mentioned above and by regulating the surface temperatures of the first drying cylinders so that the difference between the temperatures of the cylinders and the web is smaller than the maximal temperature given by said model.
- this model can have, for example, the following form:
- T0 is an empiric invariable or an invariable determined by computing
- K is an empiric invariable or an invariable determined by computing
- M is the moisture content of the web before the first cylinder.
- M is the moisture content of the web before the first cylinder as a percentage of the total weight of the web.
- T0 is an invariable dependent on web temperature Tr and on basis weight BW,
- k1 and k2 are invariable coefficients
- f(M) and f(v) are functions of web moisture M and on machine speed v.
- v is the machine speed (metres per second).
- the regulation model is, for each paper grade and paper quality to be produced, of the form:
- ⁇ T ⁇ T (Tr, v, M, BW)
- the control algorithm solutions described above are also affected by limitations arising from quality factors, so that the initial part of the dryer section is quite significant from the point of view of the paper quality.
- the web In the initial part of the dryer section the web may end up in such a range of temperature-moisture that the fibres are softened.
- the initial drying temperature becomes higher, among other things the following changes are noticed in the properties of the web: the coefficient of scattering of light becomes lower, the tensile strength and density become higher, the permeability to air is lowered, and the roughness of the surface is increased.
- the calendering quality of the paper is deteriorated. The magnitude of the effect depends on the yield of stock so that the effects are highest with mechanical pulps, but are reduced rapidly when the yield becomes lower.
- the surface temperatures of the drying cylinders can be measured by means of IR measurements, for example by means of an IR camera, or by using particular apparatuses developed for measurement of the surface temperature of a cylinder. Such an apparatus has been described, for example in the journal Paper Technology, June 1998, page 17. From the prior art, various temperature detectors that reach contact with the face of a drying cylinder are also known.
- the steam pressures in the first cylinders are lowered from the level of a normal running situation.
- the surface temperatures of the first drying cylinders are regulated to a suitable level for the time of threading, and after threading the temperatures are raised, based on a pre-determined sequence or on measurement of the ultimate dry solids content, to the level corresponding to the normal running situation. If necessary, the moisture content and the temperature of the lead-in strip before the first drying cylinders can be measured.
- the steam pressures in the first cylinders are lowered in the usual way, and after this the evaporation load is equalized by moistening the wire.
- the web moisture and the web temperature preceding the first drying cylinders are measured after the web break in order that it should be possible to make the necessary corrections either by means of impingement drying, if there is an impingement drying unit in the initial part of the dryer section before the first drying cylinders, and/or by means of a steam box in the press section and/or by means of press loads. If the measurement also provides the cross-direction profiles of moisture and temperature, by means of said devices it is also possible to correct possible profile defects.
- the surface temperatures of the first cylinders are monitored.
- the temperature is used as an indirect indicator of the conduct of the web on the cylinder concerned.
- apparatuses based on a video camera and picture processing, or a laser rangefinder by whose means the conduct of the web in the opening wire-cylinder gap is monitored directly.
- Such a technology is, however, clearly more expensive and more complicated than measurement of temperature, and it is probable that even in such a case measurement of the surface temperature of the cylinder would be advantageous in view of regulation of the system.
- the measurements can also be carried out with a web of full width in order that information could be obtained on the profile parameters of the web and that necessary regulation could be performed in respect of the profile properties of the web.
- the running parameters of the initial part of the dryer section are chosen on the basis of the most unfavourable point measured from the cross-direction profile.
- FIG. 1 is a schematic illustration of an initial part of a dryer section in which the regulation in accordance with the invention is applied, comprising an impingement drying unit between the press section and the cylinder drying.
- FIG. 2 is a schematic illustration of a press section and of an initial part of a press section following after the press section, wherein the regulation in accordance with the invention is applied.
- FIG. 3 is a schematic illustration of the arrangement in accordance with the invention.
- FIG. 1 shows a preferred exemplifying embodiment of the invention, in which the paper web W is passed from the press section 10 of the paper machine on the bottom face of a transfer fabric 11 , while supported by a PressRunTM box 11 a , onto the top face of the drying wire or belt 12 over its guide roll 13 .
- the planar drying unit R 1 comprises a blow hood 15 , under which the web W to be dried runs on the horizontal run of the wire or belt 12 , which run is supported by rolls 14 . By means of the unit R 1 , an intensive impulse of drying energy is applied to the web W.
- the paper web runs on support of the upper run of the drying wire 12 along a linear path in the horizontal plane so that it has no great changes in the direction and, thus, the web is not subjected to high dynamic forces, which might produce a web break in the web, which is still relatively moist and, therefore, of low strength.
- Inside the blow hood 15 there is a nozzle arrangement, by whose means hot drying gases, such as air or steam, are blown onto the top face of the web. Additionally, or alternatively, it is possible to use infrared heaters.
- Said blow devices and/or radiation devices in the unit R 1 can be arranged so that their capacity can be regulated in the cross direction of the web W in order to achieve cross-direction profiling of the web W.
- the unit R 1 is followed by a first, so-called normal (not inverted) single-wire unit R 2 , onto whose drying wire 22 the web W is transferred as a closed draw in the area of the first reversing suction roll 21 .
- the single-wire unit R 2 and so also the following single-wire unit R 4 which is open towards the bottom, comprise steam-heated contact-drying cylinders 20 fitted in the upper row and reversing suction rolls 21 fitted in the lower row, for example Metso Paper, Inc.'s said VAC rollTM. Below the cylinders 20 , there are doctors and ventilation blow devices 25 .
- the paper web W to be dried enters into direct contact with the faces of the steam-heated drying cylinders 20 , and on the reversing suction rolls 21 the web W remains at the side of the outside curve on the drying wire 22 .
- blow boxes 27 for example the Metso Paper, Inc.'s UnoRunBlowBox blow boxes, have been fitted above the suction rolls 21 . In the place of said boxes, it is, of course, possible to use suction boxes.
- the group R 2 with single-wire draw is followed by a drying unit R 3 , which comprises two contact-drying cylinders 30 and a large-diameter D 1 impingement-drying/through-drying cylinder 31 with a perforated mantle, which cylinder will be called large cylinder in the following.
- a drying wire 32 has been fitted to run around the contact-drying cylinders 30 and around the large cylinder 31 , which drying wire 32 is guided by guide rolls 33 .
- the impingement-drying/through-drying hood module M 1 of the drying unit R 1 has been fitted in the basement space KT below the floor level K 1 of the paper machine hall on the floor plane K 2 of said space KT.
- the central axes of the contact-drying cylinders 30 in the unit R 3 are placed substantially in, or in the vicinity of, the floor level K 1 of the paper machine hall, most appropriately slightly above said level.
- the paper web W to be dried is passed from the single-wire unit R 2 as a closed draw onto the first drying cylinder 30 in the drying unit R 3 , after which the web W is passed on the wire 32 of the unit R 3 over the large cylinder 31 of the first module M 1 within a remarkably large sector on support of the drying wire 32 , and further onto the second drying cylinder 30 in the unit R 3 . From this drying cylinder 30 the web W is transferred as a closed draw into the following normal unit R 4 with single-wire draw, which unit is, for example, substantially similar to the unit R 2 described above. After this, there follow groups of drying cylinders and/or impingement-drying units.
- the drying units R 3 ,R 4 can also be, for example, substantially similar to the drying unit R 2 described above.
- the press section shown in FIG. 1 has a drive of its own, so also the transfer belt, the planar dryer and all of the dryer groups following after it.
- a fabric is most commonly driven by means of a driven roll or rolls.
- driven rolls have been denoted with a mark ⁇ circle over (x) ⁇ applied to the shaft.
- FIG. 2 shows a second preferred exemplifying embodiment of the invention.
- the web W is passed between the felts H 1 and H 2 when it enters into the press section 10 .
- the felt H 1 has been passed over felt guide rolls 61 1
- similarly the felt H 2 has been passed over felt guide rolls 61 2 .
- the web W is passed into the first press 71 in the press 10 . From the nip N 1 of the first press 71 the web is transferred further into the nip N 2 of the second press 72 , and further into the nip N 3 of the third press 73 in the press section 10 . After this the web W is transferred from the nip N 3 of the third press 73 through a free draw F 1 onto a transfer roll 65 .
- the web W is guided further from the roll 65 into connection with a press felt H 4 , and along with said felt into the nip N 4 of the fourth press 74 .
- the felt H 4 has been passed over the felt guide rolls 61 4 .
- the felt H 3 has been passed over the felt guide rolls 61 3 .
- the web is passed further from said second transfer roll 68 into the dryer section R into its first dryer group R 2 onto the first drying cylinder 20 in said group along with the bottom face of the wire 22 of the single-wire draw while the web is supported by a vacuum produced by a blow box 69 .
- FIGS. 1 and 2 in accordance with the invention, in connection with the first drying cylinders 20 in the initial part of the dryer section, devices 91 for measurement of the surface temperatures of said cylinders have been fitted. Besides this, before the first drying cylinders, measurement devices 92 have been fitted for measurement of the temperature and of the moisture/dry solids of the paper web W. From the prior art, for example, various infrared-based measurement apparatuses not contacting the web are known for this purpose. From these measurements, there is a connection through a control unit 93 to the press section 10 for regulation of the press loads and/or of the steam box/boxes 81 , 82 in the press section and/or for regulation of the impingement drying unit R 1 . In addition to this, based on the measurement results, the steam pressures in the first cylinders 20 are regulated so as to reach the desired surface temperatures by means of regulation 95 of the steam pressures.
- the surface temperatures of the first drying cylinders 20 in the dryer section R are measured by means of the measurement apparatuses 91 , and the temperature and the dry solids/moisture of the paper web are measured by means of the measurement apparatus 92 before the first drying cylinders 20 , and based on the measurement results, by means of the control unit 93 , the surface temperatures of the first drying cylinders 20 are regulated to the desired level by means of regulation 95 of steam pressure. Further, it is possible to regulate the blow parameters of the impingement drying unit (FIG.
- the measurement apparatuses can be, for example, apparatuses in themselves known based on IR measurements or corresponding suitable measurement apparatuses.
- the steam pressures in the first cylinders 20 are lowered in the first dryer group R 2 , and the temperature of the impingement drying hood R 1 (FIG. 1) is also lowered.
- the surface temperatures of the first drying cylinders 20 are regulated to a suitable level by means of regulation 95 of steam pressures by means of the control unit 93 , and likewise, in the exemplifying embodiment shown in FIG. 1, the blow parameters of the impingement drying hood R 1 are regulated based on the results obtained from the measurements of the surface temperatures of the drying cylinders 20 by means of the measurement apparatus 91 .
- the regulation it is possible to use the measurement results obtained from the apparatus 92 for measurement of the dry solids/moisture of the web. Based on the measurement results, if desired, it is also possible to regulate the press loads in the presses 71 , 72 , 73 , 74 in the press section 10 in order to obtain a correct moisture for the lead-in strip, and, further, in the regulation operations, it is possible to employ regulation of the steam boxes 81 , 82 in the press section 10 . Further, the measurement results can be used as an aid when the differences in speed 94 between the dryer groups in the dryer section are regulated.
- FIG. 3 is a schematic illustration of the arrangement in accordance with the invention. Said illustration shows the steam box 81 ; 82 in the press section 10 , the press nip N 1 ;N 2 ;N 3 ;N 4 , of which there can, of course, be several, apparatuses 92 for measurement of the moisture and the temperature of the paper before the first cylinder 20 , as well as a possible impingement drying unit 15 and the first drying cylinder 20 .
- the steam box 81 ; 82 of the press 10 can be controlled directly on the basis of the measured moisture and temperature data (dashed line), but in addition to this they can be regulated by using a control based on a computing model as an aid, in which control the parameters 96 include, among other things, machine speed, stock data, basis weight, etc.
- This program attempts to optimize the runnability of the dryer section R, while taking into account possible criteria of quality, if any, by means of said differences in moisture and temperature and by means of the surface temperature of the cylinder measured by means of the measurement apparatus 91 .
- the actuators that can be regulated are the surface temperature of the cylinder 20 , capacity of the impingement drying 15 , and the steam box 81 ; 82 of the press 10 and the press loads.
- the optimizing algorithm it is possible to use any prior-art method whatsoever provided that the effects of said parameters are known, for example, based on an empiric or computed model.
- a model-predictive multi-variable regulation and/or optimization is/are employed.
- the input parameters of the model are the capacity of the steam box, the press load and/or any other control parameter that affects the drying capacity, the heating capacity of the impingement drying unit (flow speed and/or temperature), and/or the heating capacity of the first cylinder (pressure or equivalent).
- the output parameters of the model are moisture and/or temperature of the web after the press and/or temperature of the first cylinder.
Abstract
Description
- This application is a continuation of PCT application No. PCT/F199/00990, filed Nov. 29, 1999, and claims priority on Finnish Application No. 982622, filed Dec. 4, 1998, the disclosures of both of which applications are incorporated by reference herein.
- Not applicable
- The invention concerns a method for regulation of the initial part of the dryer section in a paper machine, in which method moisture is removed from the paper web in the dryer section and in which method the paper web is dried in the dryer section, in which method the paper web to be dried is passed from the press section into the dryer section into the first group of drying cylinders, in which the paper web is dried against heated faces of drying cylinders.
- Further, the invention concerns an equipment for regulation of the initial part of the dryer section in a paper machine, which equipment has been fitted in connection with the press section and with the dryer section in the paper machine.
- As is known from the prior art, in multi-cylinder dryers in paper machines, twin-wire draw and/or single-wire draw is/are employed. In twin-wire draw the groups of drying cylinders comprise two wires, which press the web, one from above and the other one from below, against heated cylinder faces. In twin-wire draw, between the rows of drying cylinders, which are usually horizontal rows, the web has free and unsupported draws, which are susceptible of fluttering, which may cause web breaks, in particular in the stages of drying in which the web is still relatively moist and, therefore, of low strength. This is why, in the course of the last 15 years, ever increasing use has been made of the single-wire draw, in which each group of drying cylinders comprises just one drying wire, on whose support the web runs through the whole group so that the drying wire presses the web on the drying cylinders against heated cylinder faces, and on the reversing cylinders or rolls placed between the drying cylinders the web remains at the side of the outside curve. Thus, in single-wire draw, the drying cylinders are placed outside the wire loop and the reversing cylinders or rolls inside the loop. In order to heat the faces of the drying cylinders, steam is passed into their interior, and the temperature of the surface of a heated drying cylinder is regulated so that the pressure of the steam present in the interior of the cylinder is regulated.
- In view of the cylinder drying and in view of the runnability of the paper web and of the quality properties of the paper, the first drying cylinders placed in the beginning of the dryer section are highly important. If the temperatures of the first drying cylinders are too high, the paper web has a tendency to follow the face of the cylinder, which causes problems of runnability and thereby restricts the running speed. Likewise, the brightness of the paper web becomes lower, the porosity increases, the roughness increases, formation of dust increases, and the bulk may become lower. On the other hand, if the temperatures of the first drying cylinders are too low, the drying cylinders in the initial part of the dryer section are inefficient.
- During threading of the web, even though the steam pressure has normally been switched off for this time or the steam pressure has been lowered to a level lower than a normal running situation in respect of the cylinders in the initial part of the dryer section, most commonly by lowering the pressure in the principal steam group, the lead-in strip has adhered to the drying cylinders, because the faces of the first drying cylinders are hot since the energy-consuming paper web is not present on them, in which case, thus, the web does not consume the thermal energy of the drying cylinders. Adhering of the lead-in strip has caused threading problems and thereby lowered the efficiency of the paper machine.
- In the prior-art multi-cylinder dryers, in the initial part of the dryer section, it has been a further problem that it has not been possible to use a temperature sufficiently high in view of optimal drying, because, when the paper web is in direct contact with the hot faces of the drying cylinders, at temperatures higher than a certain level the web tends to adhere to the hot faces of the cylinders, which results in web breaks and standstills. It has also been noticed that excessively hot contact drying cylinders have detrimental effects on the quality properties of the paper. On the other hand, excessively low temperatures result in lowered drying efficiency.
- At the first drying cylinders, problems have also arisen from the fact that, when the paper web starts becoming warm, it stretches, and when it stretches, it loses some of its tension, in which connection the web tends to follow the drying cylinder, which may cause problems of runnability. Traditionally, these problems have been solved so that a difference in speed has been arranged between the press section and the dryer section in order to maintain the web tension. Further, differences in speed have been employed between the first dryer groups in order to produce an adequate tension. However, excessive differences of draw have negative effects on the properties of the final product, because, when the paper is pulled, in particular its strength properties both in the machine direction and in the cross direction change.
- One prior-art solution of the type described above is known from the publication EP 0,769,587. In said prior-art arrangement the draw applied to the web is increased constantly so that a number of short dryer groups are employed in the initial part of the dryer section, which is unfavourable in view of the costs, because, among other things, extra drives, wires and wire guides are needed.
- Important factors which affect the temperatures of the first cylinders in a dryer section include, among other things, the paper grade to be produced, the web moisture after the press section, and the temperature of the paper web. Usually, information on these factors in combination with the steam pressures in the first drying cylinders employed in cylinder drying has been obtained empirically only.
- The current development in paper manufacture is about to lead in a situation in which there is no open draw between the press section and the dryer section, but a closed draw is concerned, in which case no high differences in speed can be employed, for which reason the problems described above in relation to the stretch of the web are emphasized.
- The object of the present invention is to provide a solution for the problems described above.
- It is a further object of the invention to provide a drying method and a dryer section that makes use of said method in which adhering of the web to the cylinders in the initial end of the dryer section is prevented and in which, at the same time, improved quality of the paper and improved runnability of the paper machine are achieved.
- In view of achieving the objectives stated above and those that will come out later, the method in accordance with the invention is mainly characterized in that, in the method, the surface temperatures of the first drying cylinders in the dryer section are measured, that, in the method, the dry solids content/moisture content of the paper web and the temperature of the paper web before said first drying cylinders are measured, and that, in the method, in view of producing the desired running situation, based on the measurement results obtained, the surface temperatures of said first drying cylinders and/or the dry solids content/moisture content and/or the temperature of the paper web before said first drying cylinders is/are regulated.
- On the other hand, the dryer section in accordance with the invention is mainly characterized in that the equipment comprises measurement devices fitted in connection with the first drying cylinders in the dryer section for measurement of the surface temperatures of said first drying cylinders, a measurement device for measurement of the dry solids content/moisture content of the paper web and of the temperature of the paper web before said first drying cylinders, and a control device for regulation of the surface temperatures of said first drying cylinders and/or of the dry solids content/moisture content and/or of the temperature of the paper web before said first drying cylinders, based on the measurement results obtained by means of the measurement devices, to produce the desired running situation.
- In accordance with the invention, the surface temperatures of the first drying cylinders in the dryer section and the dry solids / moisture content of the paper web and the temperature of the web before the first drying cylinders are measured, and on the basis of the measurement results the surface temperatures of the first drying cylinders are regulated to the desired level so that a good running situation is achieved.
- Besides by means of the steam pressure/flow, the surface temperatures of the first drying cylinders can, of course, also be regulated by means of other known methods, for example by means of induction heating or by means of electrical resistors.
- The highest possible difference in temperature that provides good runnability depends on a number of different factors: paper grade and basis weight, stock that is used, web temperature, moisture content, fibre orientation, and machine speed. This is why it is often not possible to present a precise model for a correct maximal difference in temperature, but the regulation algorithms must be based on empiric information. It is known that the strength properties of different paper grades depend on the fibrous raw-material that is used and on the various properties of said material. The fibrous raw-material, its grinding degree, and possible additives and fillers affect the tendency with which the web, when moist, attempts to adhere to a hot cylinder face. In practice, these are, however, factors which cannot be changed for the sake of the runnability in the initial part of the dryer section alone, but the decisive factor is the paper quality. The same is true concerning the fibre orientation, even though it is known that a highly oriented web would be stronger in the machine direction.
- The web temperature has two factors which act in opposite directions. On one hand, it has been noticed that, when the web is hotter, it does not adhere to the first hot faces equally well. On the other hand, the web strength becomes lower when the temperature becomes higher. The machine speed does not have a direct intensive effect on the adhering of the web to the first cylinder, but, on the other hand, it produces a vacuum in the opening web-cylinder gap, as a result of which vacuum the web tends to follow the cylinder face. This diverts the web from the face of the support wire and, thus, subjects the web to centrifugal forces which are increased in direct proportion to the second power of the speed.
- The web moisture has a great negative effect on the runnability of the initial part of the dryer section. First, experience has shown that a moist web has an intensive tendency to adhere to a cylinder face. In practice, this has caused, e.g., formation of dust and a so-called Tinting effect. On the other hand, the web strength becomes lower when the moisture content becomes higher.
- A solution is included in the scope of the present invention in which a regulation model has been formed by using at least some of the parameters mentioned above and by regulating the surface temperatures of the first drying cylinders so that the difference between the temperatures of the cylinders and the web is smaller than the maximal temperature given by said model. In its simplest form, this model can have, for example, the following form:
- ΔY=T0−K * M, wherein
- T0 is an empiric invariable or an invariable determined by computing,
- K is an empiric invariable or an invariable determined by computing, and
- M is the moisture content of the web before the first cylinder.
- One such equation of regulation might be
- ΔT(°C)=48−5 * M, wherein
- M is the moisture content of the web before the first cylinder as a percentage of the total weight of the web.
- The equation is valid in the range 35%<M<60%.
- A form that is slightly more common is represented by
- ΔT=T0(Tr, BW)−k1* f(M)−k2* f(v), wherein
- T0 is an invariable dependent on web temperature Tr and on basis weight BW,
- k1 and k2 are invariable coefficients, and
- f(M) and f(v) are functions of web moisture M and on machine speed v.
- An example of such a regulation model is the equation:
- ΔT(°C.)=60−6*M−0.01* v, wherein
- v is the machine speed (metres per second).
- Of course, in its commonest form, the regulation model is, for each paper grade and paper quality to be produced, of the form:
- ΔT=ΔT (Tr, v, M, BW),
- but, as was stated earlier, this is often quite difficult to determine precisely.
- The control algorithm solutions described above are also affected by limitations arising from quality factors, so that the initial part of the dryer section is quite significant from the point of view of the paper quality. In the initial part of the dryer section the web may end up in such a range of temperature-moisture that the fibres are softened. When the initial drying temperature becomes higher, among other things the following changes are noticed in the properties of the web: the coefficient of scattering of light becomes lower, the tensile strength and density become higher, the permeability to air is lowered, and the roughness of the surface is increased. At the same time the calendering quality of the paper is deteriorated. The magnitude of the effect depends on the yield of stock so that the effects are highest with mechanical pulps, but are reduced rapidly when the yield becomes lower. One consequence of the softening of the fibres by the effect of the drying temperature is adhering of fibres to the faces of the cylinders in the initial part of the dryer section if the temperatures of the cylinders are excessively high in the beginning, which effect occurs with printing papers that contain mechanical pulp. When the fibres adhere to the cylinders, they rise upright when the web is separated from the cylinder. This causes dust formation in the paper during printing. A certain contribution to such adhesion is given by various additives of paper, such as stock sizes. In accordance with the present invention, these factors present in the initial part of the dryer section are taken into account when the surface temperatures of the drying cylinders are regulated in accordance with the invention so that a good running situation is achieved.
- The surface temperatures of the drying cylinders can be measured by means of IR measurements, for example by means of an IR camera, or by using particular apparatuses developed for measurement of the surface temperature of a cylinder. Such an apparatus has been described, for example in the journalPaper Technology, June 1998, page 17. From the prior art, various temperature detectors that reach contact with the face of a drying cylinder are also known.
- After a paper web break, the steam pressures in the first cylinders are lowered from the level of a normal running situation. Based on the results obtained from measurements of the surface temperatures of the first drying cylinders, the surface temperatures of the first drying cylinders are regulated to a suitable level for the time of threading, and after threading the temperatures are raised, based on a pre-determined sequence or on measurement of the ultimate dry solids content, to the level corresponding to the normal running situation. If necessary, the moisture content and the temperature of the lead-in strip before the first drying cylinders can be measured.
- Based on the moisture content of the lead-in strip, the possibilities of success of the following threading can be estimated, because the moisture value predicts the runnability. An excessively moist lead-in strip is of low strength, and it adheres readily to the first drying cylinders. It also stretches easily and makes successful threading of the web more difficult.
- Based on the measurement results, if necessary, it is also possible to regulate the press loads in the press section in order to obtain sufficient strength of the lead-in strip so as to provide a successful threading. In addition to this, based on the measurement results, it is possible to select suitable differences of draw between the press section and the dryer section and between the first groups in the dryer section as a function of the speed.
- In accordance with a favourable additional feature of the invention, in the event of a web break, the steam pressures in the first cylinders are lowered in the usual way, and after this the evaporation load is equalized by moistening the wire. The web moisture and the web temperature preceding the first drying cylinders are measured after the web break in order that it should be possible to make the necessary corrections either by means of impingement drying, if there is an impingement drying unit in the initial part of the dryer section before the first drying cylinders, and/or by means of a steam box in the press section and/or by means of press loads. If the measurement also provides the cross-direction profiles of moisture and temperature, by means of said devices it is also possible to correct possible profile defects.
- During normal running, based on the measurement results, it is possible to optimize the surface temperatures of the drying cylinders, the differences of draw in the initial part of the dryer section, and, if necessary, to change the press loads or to control the steam box of the press section so that an optimal running situation is achieved. Also, in a preferred embodiment of the present invention, based on the measurement results, it is possible to regulate the blow parameters of an impingement drying unit, which may have been fitted before the first drying cylinders, in compliance with the dry solids content and the temperature of the web.
- In accordance with the invention, the surface temperatures of the first cylinders are monitored. The temperature is used as an indirect indicator of the conduct of the web on the cylinder concerned. Of course, it would also be possible to use, for example, apparatuses based on a video camera and picture processing, or a laser rangefinder, by whose means the conduct of the web in the opening wire-cylinder gap is monitored directly. Such a technology is, however, clearly more expensive and more complicated than measurement of temperature, and it is probable that even in such a case measurement of the surface temperature of the cylinder would be advantageous in view of regulation of the system.
- In an additional embodiment of the invention, based on said measurements of the surface temperatures of the cylinders and/or on the measurements of the web moisture and/or web temperature, it is possible to regulate the vacuums at least in the first suction rolls and/or the capacities of the blow/suction boxes. With respect to the regulation of the vacuum, reference is made to U.S. Pat. No. 5,535,527. The applicant has noticed that, as a rule, when the web moisture and/or temperature become(s) higher, the web must be supported more efficiently in the initial part of the dryer section. The same is true regarding the surface temperature of a cylinder, but not to an equally great extent, in particular if the difference in temperature between the web and the cylinder is not excessively large.
- In accordance with the present invention, the measurements can also be carried out with a web of full width in order that information could be obtained on the profile parameters of the web and that necessary regulation could be performed in respect of the profile properties of the web. In a preferred embodiment of the invention, the running parameters of the initial part of the dryer section are chosen on the basis of the most unfavourable point measured from the cross-direction profile.
- In the following, the invention will be described with reference to the figures in the accompanying drawing, the invention being, however, not supposed to be strictly confined to the details of said illustrations.
- FIG. 1 is a schematic illustration of an initial part of a dryer section in which the regulation in accordance with the invention is applied, comprising an impingement drying unit between the press section and the cylinder drying.
- FIG. 2 is a schematic illustration of a press section and of an initial part of a press section following after the press section, wherein the regulation in accordance with the invention is applied.
- FIG. 3 is a schematic illustration of the arrangement in accordance with the invention.
- FIG. 1 shows a preferred exemplifying embodiment of the invention, in which the paper web W is passed from the
press section 10 of the paper machine on the bottom face of atransfer fabric 11, while supported by aPressRun™ box 11 a, onto the top face of the drying wire orbelt 12 over itsguide roll 13. The planar drying unit R1, comprises ablow hood 15, under which the web W to be dried runs on the horizontal run of the wire orbelt 12, which run is supported byrolls 14. By means of the unit R1, an intensive impulse of drying energy is applied to the web W. In the unit R1 the paper web runs on support of the upper run of thedrying wire 12 along a linear path in the horizontal plane so that it has no great changes in the direction and, thus, the web is not subjected to high dynamic forces, which might produce a web break in the web, which is still relatively moist and, therefore, of low strength. Inside theblow hood 15, there is a nozzle arrangement, by whose means hot drying gases, such as air or steam, are blown onto the top face of the web. Additionally, or alternatively, it is possible to use infrared heaters. Said blow devices and/or radiation devices in the unit R1 can be arranged so that their capacity can be regulated in the cross direction of the web W in order to achieve cross-direction profiling of the web W. - In FIG. 1, the unit R1 is followed by a first, so-called normal (not inverted) single-wire unit R2, onto whose
drying wire 22 the web W is transferred as a closed draw in the area of the first reversingsuction roll 21. The single-wire unit R2, and so also the following single-wire unit R4 which is open towards the bottom, comprise steam-heated contact-dryingcylinders 20 fitted in the upper row and reversing suction rolls 21 fitted in the lower row, for example Metso Paper, Inc.'s said VAC roll™. Below thecylinders 20, there are doctors andventilation blow devices 25. The paper web W to be dried enters into direct contact with the faces of the steam-heated drying cylinders 20, and on the reversing suction rolls 21 the web W remains at the side of the outside curve on thedrying wire 22. In order to improve the runnability, blowboxes 27, for example the Metso Paper, Inc.'s UnoRunBlowBox blow boxes, have been fitted above the suction rolls 21. In the place of said boxes, it is, of course, possible to use suction boxes. - In FIG. 1, the group R2 with single-wire draw is followed by a drying unit R3, which comprises two contact-drying
cylinders 30 and a large-diameter D1 impingement-drying/through-dryingcylinder 31 with a perforated mantle, which cylinder will be called large cylinder in the following. A drying wire 32 has been fitted to run around the contact-dryingcylinders 30 and around thelarge cylinder 31, which drying wire 32 is guided by guide rolls 33. The impingement-drying/through-drying hood module M1 of the drying unit R1 has been fitted in the basement space KT below the floor level K1 of the paper machine hall on the floor plane K2 of said space KT. The central axes of the contact-dryingcylinders 30 in the unit R3 are placed substantially in, or in the vicinity of, the floor level K1 of the paper machine hall, most appropriately slightly above said level. The paper web W to be dried is passed from the single-wire unit R2 as a closed draw onto thefirst drying cylinder 30 in the drying unit R3, after which the web W is passed on the wire 32 of the unit R3 over thelarge cylinder 31 of the first module M1 within a remarkably large sector on support of the drying wire 32, and further onto thesecond drying cylinder 30 in the unit R3. From this dryingcylinder 30 the web W is transferred as a closed draw into the following normal unit R4 with single-wire draw, which unit is, for example, substantially similar to the unit R2 described above. After this, there follow groups of drying cylinders and/or impingement-drying units. The drying units R3,R4 can also be, for example, substantially similar to the drying unit R2 described above. - The press section shown in FIG. 1 has a drive of its own, so also the transfer belt, the planar dryer and all of the dryer groups following after it. A fabric is most commonly driven by means of a driven roll or rolls. In FIG. 1, and likewise in FIG. 2, driven rolls have been denoted with a mark {circle over (x)} applied to the shaft.
- FIG. 2 shows a second preferred exemplifying embodiment of the invention. The web W is passed between the felts H1 and H2 when it enters into the
press section 10. The felt H1 has been passed over felt guide rolls 61 1, and similarly the felt H2 has been passed over felt guide rolls 61 2. The web W is passed into thefirst press 71 in thepress 10. From the nip N1 of thefirst press 71 the web is transferred further into the nip N2 of thesecond press 72, and further into the nip N3 of thethird press 73 in thepress section 10. After this the web W is transferred from the nip N3 of thethird press 73 through a free draw F1 onto atransfer roll 65. The web W is guided further from theroll 65 into connection with a press felt H4, and along with said felt into the nip N4 of thefourth press 74. The felt H4 has been passed over the felt guide rolls 61 4. Similarly, the felt H3 has been passed over the felt guide rolls 61 3. - From the
fourth press 74 the web W is guided further through a free draw F2 onto atransfer roll 68 and further into the dryer section. - The web is passed further from said
second transfer roll 68 into the dryer section R into its first dryer group R2 onto thefirst drying cylinder 20 in said group along with the bottom face of thewire 22 of the single-wire draw while the web is supported by a vacuum produced by ablow box 69. - In FIGS. 1 and 2, in accordance with the invention, in connection with the
first drying cylinders 20 in the initial part of the dryer section,devices 91 for measurement of the surface temperatures of said cylinders have been fitted. Besides this, before the first drying cylinders,measurement devices 92 have been fitted for measurement of the temperature and of the moisture/dry solids of the paper web W. From the prior art, for example, various infrared-based measurement apparatuses not contacting the web are known for this purpose. From these measurements, there is a connection through acontrol unit 93 to thepress section 10 for regulation of the press loads and/or of the steam box/boxes first cylinders 20 are regulated so as to reach the desired surface temperatures by means ofregulation 95 of the steam pressures. - As is shown in FIGS. 1 and 2, the surface temperatures of the
first drying cylinders 20 in the dryer section R are measured by means of themeasurement apparatuses 91, and the temperature and the dry solids/moisture of the paper web are measured by means of themeasurement apparatus 92 before thefirst drying cylinders 20, and based on the measurement results, by means of thecontrol unit 93, the surface temperatures of thefirst drying cylinders 20 are regulated to the desired level by means ofregulation 95 of steam pressure. Further, it is possible to regulate the blow parameters of the impingement drying unit (FIG. 1) and/or the press loads in thepresses steam boxes speed 94 between the dryer groups. The measurement apparatuses can be, for example, apparatuses in themselves known based on IR measurements or corresponding suitable measurement apparatuses. - In a situation in which there has been a web break in the paper web and threading is carried out, the steam pressures in the
first cylinders 20 are lowered in the first dryer group R2, and the temperature of the impingement drying hood R1 (FIG. 1) is also lowered. After this, the surface temperatures of thefirst drying cylinders 20 are regulated to a suitable level by means ofregulation 95 of steam pressures by means of thecontrol unit 93, and likewise, in the exemplifying embodiment shown in FIG. 1, the blow parameters of the impingement drying hood R1 are regulated based on the results obtained from the measurements of the surface temperatures of the dryingcylinders 20 by means of themeasurement apparatus 91. In the regulation, it is possible to use the measurement results obtained from theapparatus 92 for measurement of the dry solids/moisture of the web. Based on the measurement results, if desired, it is also possible to regulate the press loads in thepresses press section 10 in order to obtain a correct moisture for the lead-in strip, and, further, in the regulation operations, it is possible to employ regulation of thesteam boxes press section 10. Further, the measurement results can be used as an aid when the differences inspeed 94 between the dryer groups in the dryer section are regulated. - FIG. 3 is a schematic illustration of the arrangement in accordance with the invention. Said illustration shows the
steam box 81;82 in thepress section 10, the press nip N1;N2;N3;N4, of which there can, of course, be several,apparatuses 92 for measurement of the moisture and the temperature of the paper before thefirst cylinder 20, as well as a possibleimpingement drying unit 15 and thefirst drying cylinder 20. Of course, thesteam box 81;82 of thepress 10 can be controlled directly on the basis of the measured moisture and temperature data (dashed line), but in addition to this they can be regulated by using a control based on a computing model as an aid, in which control theparameters 96 include, among other things, machine speed, stock data, basis weight, etc. This program attempts to optimize the runnability of the dryer section R, while taking into account possible criteria of quality, if any, by means of said differences in moisture and temperature and by means of the surface temperature of the cylinder measured by means of themeasurement apparatus 91. In the case shown in the figure, the actuators that can be regulated are the surface temperature of thecylinder 20, capacity of the impingement drying 15, and thesteam box 81;82 of thepress 10 and the press loads. As the optimizing algorithm it is possible to use any prior-art method whatsoever provided that the effects of said parameters are known, for example, based on an empiric or computed model. - According to a preferred embodiment of the invention, a model-predictive multi-variable regulation and/or optimization is/are employed. The input parameters of the model are the capacity of the steam box, the press load and/or any other control parameter that affects the drying capacity, the heating capacity of the impingement drying unit (flow speed and/or temperature), and/or the heating capacity of the first cylinder (pressure or equivalent). The output parameters of the model are moisture and/or temperature of the web after the press and/or temperature of the first cylinder.
- Above, the invention has been described with reference to some preferred exemplifying embodiments of same only, the invention being, however, not supposed to be in any way strictly confined to the details of said embodiments. Many variations and modifications are possible within the scope of the inventive idea defined in the following patent claims.
Claims (21)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI982622 | 1998-12-04 | ||
FI982622A FI104988B (en) | 1998-12-04 | 1998-12-04 | Method and plant for regulating the beginning of the drying portion of a paper machine |
PCT/FI1999/000990 WO2000034574A1 (en) | 1998-12-04 | 1999-11-29 | Method and equipment for regulation of the initial part of the dryer section in a paper machine |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FI1999/000990 Continuation WO2000034574A1 (en) | 1998-12-04 | 1999-11-29 | Method and equipment for regulation of the initial part of the dryer section in a paper machine |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020007927A1 true US20020007927A1 (en) | 2002-01-24 |
US6423184B2 US6423184B2 (en) | 2002-07-23 |
Family
ID=8553040
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/867,925 Expired - Fee Related US6423184B2 (en) | 1998-12-04 | 2001-05-30 | Method and equipment for regulation of the initial part of the dryer section in a paper machine |
Country Status (8)
Country | Link |
---|---|
US (1) | US6423184B2 (en) |
EP (1) | EP1155188B1 (en) |
AT (1) | ATE262077T1 (en) |
AU (1) | AU1660600A (en) |
CA (1) | CA2353389C (en) |
DE (1) | DE69915701T2 (en) |
FI (1) | FI104988B (en) |
WO (1) | WO2000034574A1 (en) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020112827A1 (en) * | 2000-10-17 | 2002-08-22 | Merkley Donald J. | Method and apparatus for reducing impurities in cellulose fibers for manufacture of fiber reinforced cement composite materials |
US20020170468A1 (en) * | 2001-03-09 | 2002-11-21 | Caidian Luo | Fiber reinforced cement composite materials using chemically treated fibers with improved dispersibility |
US20030205172A1 (en) * | 2000-03-14 | 2003-11-06 | Gleeson James A. | Fiber cement building materials with low density additives |
US20030222219A1 (en) * | 2000-12-22 | 2003-12-04 | Metso Automation Oy | Method and apparatus for controlling moisture profile of moving paper web |
US20040139891A1 (en) * | 2000-10-04 | 2004-07-22 | Merkley Donald J. | Fiber cement composite materials using cellulose fibers loaded with inorganic and/or organic substances |
US20040145078A1 (en) * | 2000-10-04 | 2004-07-29 | Merkley Donald J. | Fiber cement composite materials using sized cellulose fibers |
US20040168615A1 (en) * | 2003-01-09 | 2004-09-02 | Caidian Luo | Fiber cement composite materials using bleached cellulose fibers |
US20050016423A1 (en) * | 2000-10-17 | 2005-01-27 | Merkley Donald J. | Fiber cement composite material using biocide treated durable cellulose fibers |
WO2006070063A1 (en) * | 2004-12-31 | 2006-07-06 | Metso Paper, Inc. | Method of improving runnability of a drying section of a paper machine, use of a rotating drying cylinder, drying section of a paper machine and method of selecting a drying strategy |
US20060288909A1 (en) * | 2002-10-07 | 2006-12-28 | James Hardie International Finance B.V. | Durable medium-density fibre cement composite |
US20070283827A1 (en) * | 2006-06-09 | 2007-12-13 | Heidelberger Druckmaschinen Ag | Method for determining operating parameters of a printing press |
US20090151283A1 (en) * | 2005-02-15 | 2009-06-18 | James Hardie International Finance B.V. | Flooring sheet and modular flooring system |
US20090162602A1 (en) * | 2007-12-20 | 2009-06-25 | James Hardie International Finance B.V. | Structural fiber cement building materials |
US20090218720A1 (en) * | 1999-12-15 | 2009-09-03 | Hong Chen | Method and Apparatus for Extruding Cementitious Articles |
US7998571B2 (en) | 2004-07-09 | 2011-08-16 | James Hardie Technology Limited | Composite cement article incorporating a powder coating and methods of making same |
US8993462B2 (en) | 2006-04-12 | 2015-03-31 | James Hardie Technology Limited | Surface sealed reinforced building element |
WO2016061607A1 (en) * | 2014-10-24 | 2016-04-28 | Berndorf Band Gmbh | Process optimisation for a strip casting system |
Families Citing this family (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10042243A1 (en) * | 2000-08-28 | 2002-03-14 | Voith Paper Patent Gmbh | Web break monitoring method |
FI115081B (en) * | 2001-10-19 | 2005-02-28 | Metso Automation Oy | Method and apparatus for controlling the operation of a pulp department of a paper machine |
DE10305598A1 (en) * | 2003-02-11 | 2004-08-19 | Voith Paper Patent Gmbh | Material web moisture content determination method, e.g. a paper or card web, whereby an infrared moisture sensor is used that is mounted on a beam so that it can be moved over the whole web width |
CN101035455A (en) * | 2005-07-26 | 2007-09-12 | 三菱电机株式会社 | Hand dryer |
DE102007049777B4 (en) * | 2007-10-17 | 2009-11-12 | Siemens Ag | Control device and method for moisture control of a paper web and dryer section |
DE102007062454A1 (en) * | 2007-12-22 | 2009-07-02 | Robert Bosch Gmbh | Method for regulating a web tension and / or a register |
US8968517B2 (en) | 2012-08-03 | 2015-03-03 | First Quality Tissue, Llc | Soft through air dried tissue |
EP3142625A4 (en) | 2014-05-16 | 2017-12-20 | First Quality Tissue, LLC | Flushable wipe and method of forming the same |
WO2016077594A1 (en) | 2014-11-12 | 2016-05-19 | First Quality Tissue, Llc | Cannabis fiber, absorbent cellulosic structures containing cannabis fiber and methods of making the same |
WO2016086019A1 (en) | 2014-11-24 | 2016-06-02 | First Quality Tissue, Llc | Soft tissue produced using a structured fabric and energy efficient pressing |
US10099425B2 (en) | 2014-12-05 | 2018-10-16 | Structured I, Llc | Manufacturing process for papermaking belts using 3D printing technology |
US10544547B2 (en) | 2015-10-13 | 2020-01-28 | First Quality Tissue, Llc | Disposable towel produced with large volume surface depressions |
US10538882B2 (en) | 2015-10-13 | 2020-01-21 | Structured I, Llc | Disposable towel produced with large volume surface depressions |
CN109328166A (en) | 2015-10-14 | 2019-02-12 | 上品纸制品有限责任公司 | The system and method for being bundled product and forming bundle product |
WO2017139786A1 (en) | 2016-02-11 | 2017-08-17 | Structured I, Llc | Belt or fabric including polymeric layer for papermaking machine |
US20170314206A1 (en) | 2016-04-27 | 2017-11-02 | First Quality Tissue, Llc | Soft, low lint, through air dried tissue and method of forming the same |
MX2019002123A (en) | 2016-08-26 | 2019-08-16 | Method of producing absorbent structures with high wet strength, absorbency, and softness. | |
WO2018049390A1 (en) | 2016-09-12 | 2018-03-15 | Structured I, Llc | Former of water laid asset that utilizes a structured fabric as the outer wire |
US11583489B2 (en) | 2016-11-18 | 2023-02-21 | First Quality Tissue, Llc | Flushable wipe and method of forming the same |
US10619309B2 (en) | 2017-08-23 | 2020-04-14 | Structured I, Llc | Tissue product made using laser engraved structuring belt |
DE102018114748A1 (en) | 2018-06-20 | 2019-12-24 | Voith Patent Gmbh | Laminated paper machine clothing |
US11697538B2 (en) | 2018-06-21 | 2023-07-11 | First Quality Tissue, Llc | Bundled product and system and method for forming the same |
US11738927B2 (en) | 2018-06-21 | 2023-08-29 | First Quality Tissue, Llc | Bundled product and system and method for forming the same |
DE102021121870A1 (en) | 2021-08-24 | 2023-03-02 | Voith Patent Gmbh | MACHINE FOR MAKING OR TREATMENT OF A FIBROUS WEB |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3619359A (en) * | 1969-03-10 | 1971-11-09 | Beloit Corp | Gross machine moisture control system for the net end of a paper machine |
US3666621A (en) * | 1968-02-16 | 1972-05-30 | Industrial Nucleonics Corp | Process and apparatus for moisture and fiber content control in a papermaking machine |
US3748224A (en) * | 1970-11-24 | 1973-07-24 | Westinghouse Electric Corp | Control system for the pre dryer section of a paper machine |
US3864842A (en) * | 1973-04-09 | 1975-02-11 | Gorham Int Inc | Method and apparatus for drying continuous sheets |
US4314878A (en) * | 1978-01-26 | 1982-02-09 | Westvaco Corporation | Method of operating a papermachine drying line |
US4701857A (en) * | 1984-01-25 | 1987-10-20 | Robinson John W | Method and apparatus for controlling dryers for wood products, fabrics, paper and pulp |
US5377428A (en) * | 1993-09-14 | 1995-01-03 | James River Corporation Of Virginia | Temperature sensing dryer profile control |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2659987A (en) | 1952-12-13 | 1953-11-24 | Mason Neilan Regulator Company | Sheet moisture drying machine control mechanism |
US3016622A (en) * | 1957-07-10 | 1962-01-16 | Kimberly Clark Co | Control system for paper machine driers |
FR1229781A (en) | 1959-02-17 | 1960-09-09 | Advanced device allowing automatic regulation of the dryness of the paper during its manufacture | |
US5535527A (en) | 1995-06-07 | 1996-07-16 | Valmet Corporation | Method and arrangement in a multi-cylinder dryer of a paper machine |
DE19611054A1 (en) | 1996-03-20 | 1997-09-25 | Bosch Siemens Hausgeraete | dishwasher |
WO1997042032A1 (en) | 1996-05-02 | 1997-11-13 | Baldwin-Japan Ltd. | Roller temperature control system |
US6104987A (en) | 1997-10-03 | 2000-08-15 | The Nash Engineering Company | System for monitoring dryer drum temperatures |
-
1998
- 1998-12-04 FI FI982622A patent/FI104988B/en active
-
1999
- 1999-11-29 AT AT99959437T patent/ATE262077T1/en not_active IP Right Cessation
- 1999-11-29 DE DE69915701T patent/DE69915701T2/en not_active Expired - Fee Related
- 1999-11-29 EP EP99959437A patent/EP1155188B1/en not_active Expired - Lifetime
- 1999-11-29 WO PCT/FI1999/000990 patent/WO2000034574A1/en active IP Right Grant
- 1999-11-29 AU AU16606/00A patent/AU1660600A/en not_active Abandoned
- 1999-11-29 CA CA002353389A patent/CA2353389C/en not_active Expired - Fee Related
-
2001
- 2001-05-30 US US09/867,925 patent/US6423184B2/en not_active Expired - Fee Related
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3666621A (en) * | 1968-02-16 | 1972-05-30 | Industrial Nucleonics Corp | Process and apparatus for moisture and fiber content control in a papermaking machine |
US3619359A (en) * | 1969-03-10 | 1971-11-09 | Beloit Corp | Gross machine moisture control system for the net end of a paper machine |
US3748224A (en) * | 1970-11-24 | 1973-07-24 | Westinghouse Electric Corp | Control system for the pre dryer section of a paper machine |
US3864842A (en) * | 1973-04-09 | 1975-02-11 | Gorham Int Inc | Method and apparatus for drying continuous sheets |
US4314878A (en) * | 1978-01-26 | 1982-02-09 | Westvaco Corporation | Method of operating a papermachine drying line |
US4701857A (en) * | 1984-01-25 | 1987-10-20 | Robinson John W | Method and apparatus for controlling dryers for wood products, fabrics, paper and pulp |
US5377428A (en) * | 1993-09-14 | 1995-01-03 | James River Corporation Of Virginia | Temperature sensing dryer profile control |
Cited By (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090218720A1 (en) * | 1999-12-15 | 2009-09-03 | Hong Chen | Method and Apparatus for Extruding Cementitious Articles |
US20080203365A1 (en) * | 2000-03-14 | 2008-08-28 | Gleeson James A | Fiber Cement Building Materials With Low Density Additives |
US8603239B2 (en) | 2000-03-14 | 2013-12-10 | James Hardie Technology Limited | Fiber cement building materials with low density additives |
US20030205172A1 (en) * | 2000-03-14 | 2003-11-06 | Gleeson James A. | Fiber cement building materials with low density additives |
US8182606B2 (en) | 2000-03-14 | 2012-05-22 | James Hardie Technology Limited | Fiber cement building materials with low density additives |
US20100242802A1 (en) * | 2000-03-14 | 2010-09-30 | Gleeson James A | Fiber cement building materials with low density additives |
US7727329B2 (en) | 2000-03-14 | 2010-06-01 | James Hardie Technology Limited | Fiber cement building materials with low density additives |
US7658794B2 (en) | 2000-03-14 | 2010-02-09 | James Hardie Technology Limited | Fiber cement building materials with low density additives |
US20050235883A1 (en) * | 2000-10-04 | 2005-10-27 | Merkley Donald J | Fiber cement composite materials using cellulose fibers loaded with inorganic and/or organic substances |
US20040145078A1 (en) * | 2000-10-04 | 2004-07-29 | Merkley Donald J. | Fiber cement composite materials using sized cellulose fibers |
US6872246B2 (en) | 2000-10-04 | 2005-03-29 | James Hardie Research Pty Limited | Fiber cement composite materials using cellulose fibers loaded with inorganic and/or organic substances |
US7815841B2 (en) | 2000-10-04 | 2010-10-19 | James Hardie Technology Limited | Fiber cement composite materials using sized cellulose fibers |
US20040139891A1 (en) * | 2000-10-04 | 2004-07-22 | Merkley Donald J. | Fiber cement composite materials using cellulose fibers loaded with inorganic and/or organic substances |
US8133352B2 (en) | 2000-10-17 | 2012-03-13 | James Hardie Technology Limited | Method and apparatus for reducing impurities in cellulose fibers for manufacture of fiber reinforced cement composite materials |
US20050016423A1 (en) * | 2000-10-17 | 2005-01-27 | Merkley Donald J. | Fiber cement composite material using biocide treated durable cellulose fibers |
US8268119B2 (en) | 2000-10-17 | 2012-09-18 | James Hardie Technology Limited | Method and apparatus for reducing impurities in cellulose fibers for manufacture of fiber reinforced cement composite materials |
US20020112827A1 (en) * | 2000-10-17 | 2002-08-22 | Merkley Donald J. | Method and apparatus for reducing impurities in cellulose fibers for manufacture of fiber reinforced cement composite materials |
US20030222219A1 (en) * | 2000-12-22 | 2003-12-04 | Metso Automation Oy | Method and apparatus for controlling moisture profile of moving paper web |
US6780284B2 (en) * | 2000-12-22 | 2004-08-24 | Metso Automation Oy | Method and apparatus for controlling moisture profile of moving paper web |
US7857906B2 (en) | 2001-03-09 | 2010-12-28 | James Hardie Technology Limited | Fiber reinforced cement composite materials using chemically treated fibers with improved dispersibility |
US20020170468A1 (en) * | 2001-03-09 | 2002-11-21 | Caidian Luo | Fiber reinforced cement composite materials using chemically treated fibers with improved dispersibility |
US20080148999A1 (en) * | 2001-03-09 | 2008-06-26 | Caidian Luo | Fiber reinforced cement composite materials using chemically treated fibers with improved dispersibility |
US7344593B2 (en) | 2001-03-09 | 2008-03-18 | James Hardie International Finance B.V. | Fiber reinforced cement composite materials using chemically treated fibers with improved dispersibility |
US7993570B2 (en) | 2002-10-07 | 2011-08-09 | James Hardie Technology Limited | Durable medium-density fibre cement composite |
US20060288909A1 (en) * | 2002-10-07 | 2006-12-28 | James Hardie International Finance B.V. | Durable medium-density fibre cement composite |
US7942964B2 (en) | 2003-01-09 | 2011-05-17 | James Hardie Technology Limited | Fiber cement composite materials using bleached cellulose fibers |
US8333836B2 (en) | 2003-01-09 | 2012-12-18 | James Hardie Technology Limited | Fiber cement composite materials using bleached cellulose fibers |
US20040168615A1 (en) * | 2003-01-09 | 2004-09-02 | Caidian Luo | Fiber cement composite materials using bleached cellulose fibers |
US7998571B2 (en) | 2004-07-09 | 2011-08-16 | James Hardie Technology Limited | Composite cement article incorporating a powder coating and methods of making same |
US20080072449A1 (en) * | 2004-12-31 | 2008-03-27 | Metso Paper, Inc. | Method of Improving Runnability of a Drying Section of a Paper Machine, Use of a Rotating Drying Cylinder, Drying Section of a Paper Machine and Method of Selecting a Drying Strategy |
WO2006070063A1 (en) * | 2004-12-31 | 2006-07-06 | Metso Paper, Inc. | Method of improving runnability of a drying section of a paper machine, use of a rotating drying cylinder, drying section of a paper machine and method of selecting a drying strategy |
US20090151283A1 (en) * | 2005-02-15 | 2009-06-18 | James Hardie International Finance B.V. | Flooring sheet and modular flooring system |
US8993462B2 (en) | 2006-04-12 | 2015-03-31 | James Hardie Technology Limited | Surface sealed reinforced building element |
US20070283827A1 (en) * | 2006-06-09 | 2007-12-13 | Heidelberger Druckmaschinen Ag | Method for determining operating parameters of a printing press |
US7954431B2 (en) * | 2006-06-09 | 2011-06-07 | Heidelberger Druchmaschinen Ag | Method for determining operating parameters of a printing press |
US20090162602A1 (en) * | 2007-12-20 | 2009-06-25 | James Hardie International Finance B.V. | Structural fiber cement building materials |
US8209927B2 (en) | 2007-12-20 | 2012-07-03 | James Hardie Technology Limited | Structural fiber cement building materials |
WO2016061607A1 (en) * | 2014-10-24 | 2016-04-28 | Berndorf Band Gmbh | Process optimisation for a strip casting system |
KR20170075767A (en) * | 2014-10-24 | 2017-07-03 | 베른도르프 반트 게엠베하 | Process optimisation for a strip casting system |
KR102396724B1 (en) | 2014-10-24 | 2022-05-11 | 베른도르프 반트 게엠베하 | Process optimisation for a strip casting system |
Also Published As
Publication number | Publication date |
---|---|
FI982622A0 (en) | 1998-12-04 |
DE69915701D1 (en) | 2004-04-22 |
DE69915701T2 (en) | 2005-02-10 |
EP1155188B1 (en) | 2004-03-17 |
CA2353389A1 (en) | 2000-06-15 |
US6423184B2 (en) | 2002-07-23 |
CA2353389C (en) | 2007-04-03 |
AU1660600A (en) | 2000-06-26 |
ATE262077T1 (en) | 2004-04-15 |
WO2000034574A1 (en) | 2000-06-15 |
FI104988B (en) | 2000-05-15 |
EP1155188A1 (en) | 2001-11-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6423184B2 (en) | Method and equipment for regulation of the initial part of the dryer section in a paper machine | |
US5416980A (en) | Method and apparatus for reduction of curling of paper in the drying section of a paper machine | |
US5775001A (en) | Dryer sections of a paper machine | |
US6001421A (en) | Method for drying paper and a dry end of a paper machine | |
US5377428A (en) | Temperature sensing dryer profile control | |
EP0708859B1 (en) | Method for the control of the transverse profiles of a web | |
US6365004B1 (en) | Method and apparatus for drying a paper web | |
EP0943034B2 (en) | Method for drying of paper and dry end of a paper machine | |
EP1086271B1 (en) | Integrated paper machine | |
JP3271118B2 (en) | Papermaking machine dryer | |
US5884415A (en) | Paper making machine providing curl control | |
US6264792B1 (en) | Method for producing calendered paper | |
US20040050517A1 (en) | Method and device in a paper or board machine | |
US5542193A (en) | Dryer group for curl control | |
US5925407A (en) | Method for drying a surface-treated paper web in an after-dryer of a paper machine and after-dryer of a paper machine | |
US20060118257A1 (en) | Method for control of the curl of paper in the treatment of surface-sized paper, and finishing section of a paper machine | |
EP0567484B1 (en) | Method and device in the press section of a paper machine for detaching the web from the face of a press roll | |
US6280576B1 (en) | After-dryer in a paper machine | |
Poirier et al. | Papermaking | |
CA2398354C (en) | Device and method preventing evaporation of moisture and heat losses in calendering | |
EP1482089B1 (en) | Apparatus for applying air on a web | |
Pikulik | 1.1 Approach Flow System The forming process is preceded by an approach flow system that receives the aqueous fiber suspension, or stock, and prepares it for the forming process. Fibres are produced using kraft process or other pulping/bleaching processes (see Bleaching of wood pulps) and the proportions of fibers from different sources are blended here. Drained water from the forming process, known as whitewater, contains useful fibrous material and is continuously recycled back into the stock. Screens and centrifugal cleaners in the approach flow system remove oversize and heavy contaminants from the pulp. Additives such as minerals, pigments and dyes are introduced to make particular grades of paper and paper board. Air bubbles may be removed from the pulp suspension. The mass concentration, or consistency, of the suspension is kept low to prevent fibre flocculation prior to forming and is usually adjusted to a value in the range of 0.5 to 1.5%. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: METSO PAPER, INC., FINLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:VAHATALO, HARRI;KAIHOVIRTA, JUHA;LIPPONEN, JUHA;AND OTHERS;REEL/FRAME:012116/0569;SIGNING DATES FROM 20010801 TO 20010815 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20100723 |
|
AS | Assignment |
Owner name: VALMET TECHNOLOGIES, INC., FINLAND Free format text: CHANGE OF NAME;ASSIGNOR:METSO PAPER, INC.;REEL/FRAME:032551/0426 Effective date: 20131212 |