• 专利附录
  • 专利说明
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  • 类似技术
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    • 专利摘要:
    A cellulose pulp drying box for drying a web (18) of cellulose pulp comprises a lower blow box (26) for blowing gas upwards towards the web (18) via blow openings, for drying the pulp in accordance with the airborne web principle. The lower blow box (26) comprises a central zone (58) comprising blow openings (70, 72) forming a first type of perforation, and a first lateral zone (52) comprising blow openings (70, 80) forming a second type of perforation, the second type of perforation being different from the first type of perforation. The blow openings (72) of the central zone (58) forma first degree of perforation, and the blow openings (80) of the first lateral zone (52) form a second degree of perforation which is larger than the first degree of perforation. As alternative to or in combination therewith the first lateral zone (252; 352)comprises blow openings (70; 370) arranged to form an air cushion above the lateral zone (252; 352) to lift the web (18) adjacent to a lateral edge (82) thereof.
    公开号:SE1151199A1
    申请号:SE1151199
    申请日:2011-12-15
    公开日:2013-06-16
    发明作者:Christer Olsson；Roland Kampris；Rolf Petersson；Per Holmberg
    申请人:Andritz Tech & Asset Man Gmbh；
    IPC主号:
    专利说明:

    AWAPATENT ABAndritz Technology and Asset Management GmbH Office / HandlerApplication numberWe reference Vaxjo / Erik Simonsson / ESN1151199-SE-21052078 comprises blowing ladders which are adapted to blow air towards the web of cellulosic pulp for drying pulp in accordance with the principle of airborne web.
    The present invention further relates to a process for drying a web of cellulosic pulp.
    Background of the Invention Cellulose pulp is often dried in a convective type dryer operating in accordance with the principle of airborne web. An example of such a dryer is described in WO 2009/154549. Hot air is biased towards a web of cellulose mass with the help of byre blisters and lower blisters. The air which is biased through the blowing barns opposite the heat to the web for drying it and also hails the web floating above the lower blowing barns. Hot air is supplied to the blowers with the help of an air circulation system including fans and angradiators that warn the drying air. A complete cellulose dryer is shown in WO 99/36615.
    With increasing demands on increased pulp production in pulp mills follows a desire to increase the drying capacity of a pulp dryer without increasing its size or only increasing its size.
    SUMMARY OF THE INVENTION A further object of the present invention is to provide a drying pad for drying a web of cellulosic pulp, which drying pad is more effective for drying the web than prior art drying pads.
    This breathable needle is obtained by means of a drying pad for drying a web of cellulosic pulp, the drying pad comprising lower blowing lads which are arranged to blow gas upwards towards the web of cellulose pulp via blowing tips, 2 for drying the web according to the principle of airborne web. The wiper comprises at least one lower bladder comprising, seen in a horizontal direction perpendicular to a direction in which the web is to move over the lower bladder, a central zone comprising bladder openings of a first perforation type, and at least one first side zone comprising bladder openings of a second perforation type , the second type of perforation differing from the first type of perforation.
    An advantage of this drying barn is that it supports a side edge of the web more efficiently, which meant that the web moves more horizontally across its width, which results in more efficient drying. Furthermore, problems such as hammering dust generated by the side edge of the web touching a lower bladder can be reduced.
    According to one embodiment, the lower blister surface further comprises a second side zone comprising blister openings of a third perforation type which differ from the first perforation type of the central zone, the central zone being arranged between the first side zone and the second side zone. An advantage of this embodiment is that the web can be dried more efficiently, and with better support, at its two side edges.
    According to one embodiment, the bladder openings of the central zone of the lower bladder have a first degree of perforation, and the bladder openings of the lower bladder at least one first side zone have a second degree of perforation, the second degree of perforation being greater than the first degree of perforation, preferably a factor of 1.1-2. 0 greater than the first degree of perforation. An advantage of this embodiment is that the lifting force will be in the side zone. According to a preferred embodiment, the second degree of perforation is a factor of 1.1-2.0, preferably 1.1-1.7, greater than the first degree of perforation.
    According to one embodiment, the drying barn further comprises at least one upper blowing barn which comprises, seen in a horizontal direction perpendicular to a direction in which the web is to move below the upper blowing barn, central zone comprising blowing openings having a fourth degree of perforation, at least a first side zone having a fifth degree of perforation, the fifth degree of perforation being less than the fourth degree of perforation. An advantage of this embodiment is that the drying action of the upper drying tray at the side edge of the web 3 tends to compensate, at least in part, for an increased drying effect of the first side zone of the lower blowing tray.
    According to one embodiment, the upper bladder barn further comprises a second side zone having a sixth degree of perforation which is less than the fourth degree of perforation of the central zone, the central zone of the upper bladder barn being arranged between the first side zone and the second side zone. An advantage of this embodiment is that over-drying of the web at the side edges of the web can be avoided, or at least reduced.
    According to one embodiment, the first side zone of the lower bladder tray comprises bladder openings arranged to form an air cushion above the side zone for lifting the web of cellulosic pulp adjacent to its side edge. An advantage of this embodiment is that the side edge of the web has an effective support.
    According to one embodiment, the first side zone further comprises two rows of bladder openings of angled type arranged to blow the air flows towards each other. An advantage of this embodiment is that "collision" of the air river. Two opposite bladder openings of angled type create a lifting force which supports the side edge of the web of cellulosic pulp.
    According to one embodiment, the first side zone of the lower bladder bar has a width, seen in the horizontal direction which is perpendicular to a direction in which the web is to move over the lower bladder bar, of 100 to 950 mm. An advantage of this embodiment is that a suitable ski of the side edge of the web is obtained.
    According to one embodiment, the first side zone of the lower bladder is arranged to extend below the web a distance of approximately 50 to 600 mm from a side edge of the web. A first side zone that extends less than 50 mm below the track cannot provide sufficient ski for the side edge. A first side zone extending more than 600 mm below the web can provide unnecessary drying of the web without causing any improvement in the way the web moves through the dryer.
    According to one embodiment, the drying barn comprises a first drying zone comprising a first type of lower blowing barns, and a subsequent second drying zone comprising a second type of lower blowing barns. An advantage of this embodiment is that the drying zones of the drying tray can adapt to the different properties of the web, such as basis weight, strength, etc. at different positions along the dryer. According to one embodiment, at least some of the bladder openings of the first side zone have a different size than the bladder openings of the central zone. An advantage of this embodiment is that the degrees of perforation of the first side zone and the central zone, respectively, can be arranged in an efficient manner, optionally by allowing the openings to be placed according to the same sample but of different sizes.
    According to one embodiment, the first side zone has a different number of bladder openings per m2 of bladder surface than the central zone. An advantage of this embodiment is that the degree of perforation of the first side zone and the central zone, respectively, can be arranged in an efficient manner, optionally by allowing the openings to have the same size but to be placed according to different patterns.
    According to one embodiment, at least one of the lower bladder bar comprises a mixture of bladder openings of angled type and bladder openings of non-angled type. An advantage of this embodiment is that the web is supported and advanced at a selected height above the lower bladder bar, which reduces the mechanical effort on the web.
    According to one embodiment, at least one of the lower bladder bar comprises only bladder openings of non-angled type. An advantage of this embodiment is that a high drying effect is achieved.
    According to one embodiment, the drying barn comprises at least one drying deck on which at least 90% of the total number of lower blowing barns of that drying deck comprises the central zone and the first side zone. An advantage of this embodiment is that efficient drying and the legal risk that the web will touch the lower blasting barn is achieved throughout the drying deck.
    A further object of the present invention is to provide a process for drying a web of cellulosic pulp in a more efficient manner than the prior art processes.
    This object is achieved in a method of drying a web of cellulosic pulp by means of lower blowing lads arranged to blow gas upwards towards the web of cellulosic pulp via blowing openings, in order to dry the pulp in accordance with the principle of airborne web, the method comprising: using at least one lower blowing barn comprising, seen in a horizontal direction perpendicular to a direction in which the web is to move over the lower blowing barn, a central zone comprising blowing openings, and at least a first side zone comprising blowing openings, blowing a first relative gas flow in a first river sample through the web through blowing openings of the central zone, and blowing a second relative gas flow in a second river sample, which differs than the first river sample, towards the path through the blowing openings of the first side zone.
    An advantage of this method is that the web is dried efficiently with lawful generation of dust particles.
    According to one embodiment, the method comprises using in the lower bladder bar a second side zone comprising bladder openings, the central zone being arranged between the first side zone and the second side zone, and blowing a third relative gas flow in a third flow pattern, which differs from the first river pattern. towards the web through the blister openings of the other side zone. An advantage of this embodiment is that the [Dada side edges of the web] are supported on an efficient sail.
    According to one embodiment, the second relative gas flow is larger than the first relative gas flow, the second relative gas flow preferably being a factor of 1.1-2.0 larger than the first relative gas flow. An advantage of this embodiment is that the side edge of the web is prevented, at least in part, from touching the lower bladder.
    According to one embodiment, the method comprises blowing the second relative gas stream in a second river sample towards the web to form an air cushion for lifting a side edge of the web of cellulosic pulp. An advantage of this embodiment is that the side edge of the web becomes less inclined to touch the lower bladder.
    Additional features and features of the present invention will become apparent from the description and claims.
    BRIEF DESCRIPTION OF THE DRAWINGS The invention is described below in more detail with reference to the accompanying drawings, in which: Fig. 1 is a schematic side view illustrating a drying tray for drying a web of cellulosic pulp.
    Fig. 2 is a schematic side view illustrating the area II in Fig. 1.
    Fig. 3 is a front view of a first drying deck seen in the direction of the arrow III in Fig. 2.
    Fig. 4 is a top view of a first lower bladder.
    Fig. 5 is a top view of a first upper bladder barn.
    Fig. 6 is a top view of a second lower bladder barn.
    Fig. 7a is a top view of a third lower bladder.
    Fig. 7b is an enlarged view of a side zone of the third lower bladder.
    Fig. 7c is a cross-section of the side zone of Fig. 7b.
    Fig. 7d is an enlarged view of an alternative side zone.
    Fig. 7e is a cross-section of the side zone of Fig. 7d.
    Description of Preferred Embodiments Fig. 1 shows a drying pad 1 for drying cellulosic pulp according to a first embodiment of the present invention. The drying tray 1 comprises a housing 2. Inside the housing 2 a first drying zone 4, a second drying zone 6 and a possible cooling zone 8 can be arranged in a typical embodiment, the first drying zone 4 being arranged in the upper area of the housing 2, the cooling zone 8 being arranged in the lower part of the housing 2 and the second drying zone 6 is arranged between the first drying zone 4 and the cooling zone 8.
    At a first end 10 of the housing 2 a first pillar with water rollers 12 is arranged, and at a second end 14 of the housing 2 a second pillar with water rollers 16 is arranged. A wet pulp web 18 is fed into the drying tray 1 via an inlet 20 formed in the housing 2. In the embodiment in Fig. 1, the inlet 20 is formed in the upper part of the housing 2, but in an alternative embodiment the inlet may be formed in the lower the lot of the house. The web 18 is conveyed as shown in Fig. 1 horizontally at Niger in the drying barn 1 until the web 18 reaches a water roller. In the drying tray 1 shown in Fig. 1, the web 18 will first reach a water roller 16 on the second pillar with water rollers. The web 18 travels around the water roll 16 and is then moved as shown in Fig. 1 horizontally to the left in the drying tray 1 until the web 18 reaches a water roll 12 on the first pillar 7 with water rollers, at which the web 18 travels again. In this way, the web 18 moves in a zigzag shape from the top to the bottom of the drying tray 1, as illustrated by the arrows P. The web 18 leaves the drying tray 1 after being dried in the first and second drying zones 4, 6 and after cooling in the cooling zone 8 via an outlet 22, which is formed in the housing 2. In the embodiment in Fig. 1, the outlet 22 is formed in the lower part of the housing 2, but the outlet can in an alternative embodiment be formed in the upper part of the housing.
    Typically, air with a temperature of 80 to 250 ° C is used for the drying process. The web 18 of cellulosic pulp fed into the drying pad 1 tan up a web forming station upstream, which is not shown in Fig. 1, typically has a dry content of 40-60% by weight, and the web 18 of cellulosic pulp leaving the drying pad 1 has a dry content of typically 85 -95 weight-`10. The web 18 of cellulosic pulp leaving the drying pad 1 typically has a basis weight of 800 to 1500 g / m2, matt at a moisture content of 0.11 kg of water per kg of dry matter, and a thickness of 0.8 to 3 mm.
    The first drying zone 4 comprises at least one first drying deck 24 and typically 3-15 first drying decks 24. In the embodiment in Fig. 1, the first drying zone 4 comprises eight first drying decks 24. Each such first drying deck 24 comprises a number of blowers, which will be described in more detail. detailed below, and is for drying the web 18 while the web 18 moves horizontally. are arranged to blow hot drying gas towards the cellulosic pulp web 18. Typically, each first drying deck 24 comprises 20-300 first lower blowing barns 26 and the same number of first upper blowing barns 28, although only a fatal blowing barn is shown in Fig. 1 for clarity. The first lower bladders 26 have the function of keeping the web 18 in a "floating" and fixed condition, so that the web 18 is airborne at a distance from the first lower bladders 26 during the drying process, which will be described in more detail below.
    The second drying zone 6 comprises at least a second drying deck 30 and typically 5-40 second drying decks 30. In the embodiment in Fig. 1, the second drying zone 6 comprises eleven second drying decks 30. Each such second drying deck 30 comprises a number of blowing barns, which will be described in more detail. detailed below, and is 8 for drying the web 18 below the web 18 moves horizontally from a water roll 12, 16 to the next water roll 16, 12. Each second drying deck 30 includes a plurality of second lower blast lids 32 and a plurality of second upper blast lids 34, which are arranged to blow hot drying gas against the cellulosic pulp web 18. Typically, each second drying deck 30 comprises 20-300 second lower blowing barns 32 and the same number of second upper blowing barns 34, although only a fatal blowing barns are shown in Fig. 1 for clarity. The second lower bladders 32 have the function of holding the web 18 in a "floating" state, so that the web 18 is airborne at a distance from the other lower blades 32 during the drying process, which will be described in more detail below.
    The first drying decks 24 in the first drying zone 4 have a different mechanical construction than the second drying decks 30 in the second drying zone 6, which will be described in more detail below. Often, the first lower blowing barns 26 in the first drying roofs 24 will have a different mechanical construction than the second lower blowing barns 32 in the second drying roofs 30, which will be illustrated by means of an example below.
    The cooling zone 8 comprises at least one cooling deck 36, Fig. 2 showing two such cooling decks 36, each such clack 36 comprising a number of third lower blowing ladders 38 and third upper blowing ladders 40, which are arranged to blow a cooling gas against the cellulosic pulp web 18. The cooling zone 8 comprises the lower blowing blades 38 are arranged to keep the web 18 in a "liquid" state, so that the web 18 becomes airborne during the cooling process. The third lower bladders 38 may, for example, have a construction similar to the construction of the first or second bladders 26, 32, which will be described in more detail below. Typically, air with a temperature of 15 to 40 ° C is used as the cooling gas for cooling. An insulated cradle 42 separates the second drying zone 6 from the cooling zone 8.
    Fig. 2 is an enlarged side view of the area II in Fig. 1 and shows a first drying deck 24 of the first drying zone shown in Fig. 1. and the first upper bladders 28, which are arranged over the web 18. The first lower bladders 26 blow hot drying air towards the web 18, both vertically upwards towards the web 18, as shown by the arrows VU in Fig. 2, and in an angled manner. at an angle of typically 5 to 600 to the horizontal plane, as shown by arrows IU in Fig. 2. Blowing dry air at an angle to the horizontal plane through the first lower blower blades 26 provides both forces forcing the web 18 upwardly away from the blower blades 26 and forces that force the web 18 neatly towards the bladders 26. The latter effect is sometimes called the Coanda effect. This results in bladder wires 26 exerting a fixing force against the web 18, which holds the web at a comparatively selected defined distance from the bladder wires 26. Typically, the average distance, or height Hi, is between the underside of the web 18 and the upper surface of the first lower bladder wires 26. when operating the wiper blade 1 1-6 mm. If the web 18 tends to frame upwards, the fixing forces of the blower blades 26 pull the web 18 neatly, and if the web 18 tends to move downwards, the air biased from the blower cables 26 forces the web 18 upwards. Consequently, the web 18 is transported horizontally along the first drying deck 24 in a relatively fixed manner, with little movement in the vertical direction, which meant that the web 18 was subjected to limited stretching forces. The first type of upper blowing blades 28 blows hot drying air towards the web 18 vertically neat in the direction of the web 18, as illustrated by arrows VD in Fig. 2. Typically, the average distance, or height H2, is between the upper side of the web 18 and the lower surface of the first upper bladders 28 10 to 80 mm. The hot drying air which is biased from the blowing barns 26, 28 is evacuated via gaps S formed between horizontally adjacent blowing barns 26, 28.
    Fig. 3 is a front view of the first drying deck 24 seen in the direction of the arrow III in Fig. 2. Drying air is supplied from a float, which is not shown for clarity, and enters the interior 44 of the first lower blower 26 at a first end 46 of the lower bladder bar 26, as illustrated by an arrow DA1. The air supplied to the inner 44 of the blower 26 is biased towards the web 18 in the form of the air flow VU and IU via openings, which will be described below with reference to Fig. 4. To return to Fig. 3, drying air is also supplied by the Than flap, not shown and enters the inner 48 of the first upper bladder dance 28 at the first end 50 of the upper bladder shaft 28, which is indicated by an arrow DA2. The air DA2 is supplied with the inner 48 of the blower dance 28 biased towards the web 18 in the form of the air flow VD via openings, which will be described below with reference to Fig. 5.
    In order to achieve efficient drying and internal operating problems, the vertical distances between the web 18 and the lower and upper blowing blades 26, 28, respectively, should preferably be substantially constant at the heights H1 and H2, shown in Fig. 2, across the width WW of the web. It has been realized that the web in previous kanda dries in some cases can, especially at its side winds, deviate Than the desired heights H1, H2, which is shown in Fig. 3 with broken lines denoted PA. Such a deviation meant that the web 18 was not dried in an optimal way.
    The first lower blast barn 26 has a total width WB which can typically be 2-16% larger than the width 18 of the web 18. The width WW of the track 18 can typically be 1-15 meters, more typically 2-12 meters. The first lower bladder bar 26 is divided into zones along its width WB, i.e. along a horizontal direction perpendicular to the direction P in which the web 18 moves over the bladder bar 26. The first lower bladder bar 26 has a first side zone 52 aligned adjacent to the first bladder bar 26. 46, a second side zone 54 disposed adjacent to the second end 56 of the blower, 26, and a central zone 58 disposed between the first and second side zones 52, 54.
    The first upper bladder bar 28 has a first side zone 60 disposed adjacent to the first end 50 of the bladder bar 28, a second side zone 62 disposed adjacent the second duct 64 of the bladder bar 28, and a central zone 66 disposed between the first and second side zones 60, 62.
    As will be described below with reference to Fig. 4 and Fig. 5, below the side zones 52, 54, and the side zones 60, 62, the web 18 is advanced almost horizontally over the entire width WW of the web 18, as shown by a solid line in Figs. Consequently, the large deviations in the prior art from the desired heights H1, H2, which are shown by broken lines PA, can be avoided or at least substantially reduced. It is also acceptable for the web to move at a slightly higher height H1 above the lower bladder bar 26 at the side zones 52, 54, than at the central zone 58 as it does not tend to adversely affect the drying process.
    Fig. 4 is a top view of the first lower bladder bar 26 seen in the direction of the arrows IV-IV in Fig. 3. The first lower bladder bar 26 has an upper surface 68 which is directed towards the web 18 and which is, as described above with Referring to Fig. 3, divided into the first side zone 52 aligned adjacent to the first first spirit 46, the second side zone 54 aligned adjacent the second end 56 of the bladder 26, and the central zone 58 aligned between the first side zone 52 and the second side zone 54. Consequently the first and second side zones 52, 54 are aligned on opposite sides of the central zone 58.
    The central zone 58 is provided with centrally located first kind of air bladder openings 70, which are of the "angled type" which may, for example, be of a type sometimes referred to as "eyelid openings" and which are arranged in the upper surface 68. With openings of the "angled type" means that at least 25 ° A of the air blown than these openings 70 are biased at an angle less than 600 to the horizontal plane. The eyelid openings 70, which may have a construction similar to the openings called "eyelid perforations 6" in WO 97/16594, and which are described with reference to Fig. 2 and Fig. 3 in WO 97/16594, thereby cause the hot drying air to be biased by a slope resulting in the air flow IU shown in Fig. 2 of the present patent application. At least 30 ° A, often at least 40 ° A, of the total air flow supplied through the first lower bladder barrel is biased via eyelid openings 70.
    To continue with the description of Fig. 4 of the present patent application, the central zone 58 is provided with a second type of bladder opening 72 which is arranged near the blades 26 sides 74, 76. The second type of bladder openings 72 is of the "non-angled type". distributed over the upper surface 68 within the central zone 58. By "non-angled type" is meant that at least 80 ° A of the air biased through these openings 72 is biased at an angle to the horizontal plane which is at least 70 °. The second type of aperture 72 may be, for example, round, square, or triangular slides. The second type of aperture 72, if round round, may typically have a diameter of 1 to 10 mm. In one example, the second type of aperture is 72 round slides with a diameter of 2.5 mm. The second type of aperture 72 blows hot air upward to form the air flow VU shown in Fig. 2.
    To return to Fig. 4, a first degree of perforation having the central zone can be calculated by dividing the total area of the openings 70, 72 having a representative portion of the central zone 58 with the horizontally projected surface 78 having the representative portion of the upper surface 68 within 12 the central zone 58. By "representative portion" is meant a portion of the upper surface 66 which is representative with respect to blowing air toward the web 18, i.e., omitting, for example, the inlet air of the blower barn. The degree of perforation of the central zone 58 is typically 0.5-3.0%. In one example, the perforation rate of the central zone 58 is 1.5%. The degree of perforation can be varied to suit the weight, dry content, etc. of the web 18 to be dried. The second type of aperture 82 which is a non-angled type of aperture may typically occupy at least 20% of the total degree of perforation of the first lower bladders 26, and typically 30-70% of the total degree of perforation of the first lower bladders 26. The first the type of apertures 70 which are of the angled type of apertures may typically occupy at least 30% of the total degree of perforation of the first lower bladders 26, and typically 40-80% of the total degree of perforation of the first lower bladders 26.
    For example, a surface of the representative portion 78 of 4000 mm 2, and with a degree of perforation of 1.5%, the total area of the openings 70, 72 becomes 60 mm 2. If the first type of aperture 70 occupied 50% of the degree of perforation, it would correspond to 30 mm2. This meant that the second type of aperture would have a total aperture area corresponding to the remaining 30 mm2, which, with apertures 72 with a diameter of 2.5 mm, would correspond to approximately six apertures 72, each having an aperture area of approximately 4 mm2. , 9 mm2.
    The first side zone 52 is provided with centrally aligned first type of air bubble openings 70, of the ogonlock type, and of a similar construction to the first type of openings 70 of the central zone 58. Furthermore, the first side zone 52 comprises a third type of air bubble openings 80 which are provided The third type of openings 80 are of the "non-angled type" and are distributed over the upper surface 68 within the first side zone 52. The third type of air bubble openings 80 may be round, square or triangular slides. , and can, if they are round slippery, typically have a diameter of 1 to 10 mm. In one example, the third type of apertures 80 is 3.1 mm in diameter round blowing hot air upward to form the air flow VU shown in Fig. 2. Accordingly, the third type of apertures 80 of the first side zone has a different size from the second type 13 of bladder openings 72 of the central zone 58. Therefore, the openings 70, 72 of the central zone 58 form a first type of perforation, which differs from a second type of perforation formed by the openings 70, 80 of the side zone 52. The third type of bladder openings 80 of the first side zone 52 are arranged in a sample similar to the sample of the second type of bladder openings 72 of the central zone 58.
    It is possible to calculate a second degree of perforation for the first side zone in a manner similar to that described above with reference to the central zone 58. The degree of perforation of the first side zone 52 is typically 0.8-3.5%. In one example, with the third type of openings 80 having a diameter of 3.1 mm, the degree of perforation of the first side zone becomes 1.9%. Consequently, the degree of perforation of the first side zone 52 is greater than the degree of perforation of the central zone 58. In one embodiment, the degree of perforation of the first side zone 52 is a factor of 1.1-2.0, preferably 1.1-1.7, greater than the degree of perforation. consequently, if, for example, the degree of perforation of the central zone 58 is 1.5%, then the degree of perforation of the first side zone 52 is in the range of 1.65 to 3.0. The second side zone 54 may have a construction similar to that of first side zone 52. Accordingly, the second side zone 54 includes, in an example, first type openings 70 of the ogonlock type, and third type of openings 80 which are round and have a diameter of 3.1 mm, resulting in a third degree of perforation of the second side zone 54 of 1.9%. Consequently, the degree of perforation of the second side zone 54 is greater than the degree of perforation of the central zone 58.
    During operation of the drying tray 1, drying air DA1 is supplied to the first lower blowing tray 26. Since the openings 70, 72 of the central zone 58 form a first type of perforation, which differs from a second type of perforation formed by the openings 70, 80 of the side zone 52. air will be blown from the openings 70, 72 of the central zone 58 in a first river sample which differs from a second river sample in which air is blown from the openings 70, 80 of the side zone 52. Furthermore, air from the openings 70, 80 of the second side zone 54 will be blown in a third flow pattern which differs from the first flow pattern in 14 which air is biased towards the openings 70, 72 of the central zone 58. for example, the unit m3 of air per hour and mm2 of area upper surface 68, i.e. m3 / (h, mm2), which is biased towards the web 18 through the openings 70, 72 of the central zone 58 to be less than a second relative air flow, in m3 area per hour and mm2 of area upper surface 68, which is biased towards the web 18 through openings 70, 80 of the first side zone 52. Similarly, a third relative air flow, in m3 air per hour, and mm2 of area upper surface 68, i.e. m3 / (h, mm2), which is biased towards the web 18 through the openings 70,80 of the second side zone 54 to be larger than the first relative air flow of the central zone 58. This results in an improved lifting force on the web 18 at the side zones 52, 54, i.e. an improved lifting force adjacent the side edges 82, 84 of the web 18 so that the web "floats" in the desired manner, as shown in Fig. 3, above the first lower blowing barn 26. Furthermore, the drying effect will 6 at the side edges 82, 84 due to the greater flow of air at the side zones 62, 54 relative to the central zone 58. According to one embodiment, the second and third relative air flows are biased by the first and second side zones 52, respectively. 54 a factor of 1.12.0, preferred 1.1-1.7, greater than the first relative airflow biased by the central zone 58.
    The first side zone 52 may typically extend a distance DZ1 of approximately 50 to 600 mm below the web 18 tan side edge 82. Similarly, the second side zone 54 may extend a distance DZ2 of approximately 50 to 600 mm into below the web 18 tan side edge. 84. Blasladan 26 has, as described above, a width WB which is greater than the width WW of the web 18. The first side zone 52 preferably has a total width LZ1, seen Man the first duct 46, of 100 to 950 mm, and the second side zone 54 has a total width LZ2, seen -Iran the second duct 56, of 100 to 950 mm. The central zone 58 is preferably at least as wide as each of the side zones 52, 54. Consequently, if the side zones 52, 54, for example, have the widths LZ1 and LZ2, respectively, of 400 mm, then the central zone is at least 400 mm wide.
    In one example, the bladder bar 26 has a width WB of 5000 mm, the web 18 has a width WW of 4600 mm, each of the first and second side zones 52, 54 has a width LZ1 and LZ2 of 500 mm, respectively, and the central zone 58 has a width LC of 4000 mm, which means that the first side zone 52 extends below the web 18 a distance DZ1 of approximately 300 mm from the side edge 82, and the second side zone 54 extends below the web 18 a distance DZ2 of approximately 300 mm from side edge 84.
    Fig. 5 is a top view of the first upper bladder bar 28 seen in the direction of the arrows VV in Fig. 3. The first upper bladder bar 28 has a lower surface 86 which is directed towards the web 18 and which is, as described above with reference to Fig. 3, divided into the first side zone 60 aligned adjacent to the first spirit 50, the second side zone 62 aligned adjacent the second end 64 of the blower, 28, and the central zone 66 aligned between the first side zone 60 and the second side zone 62.
    The central zone 66 is provided with a fourth type of air bladder openings 88 distributed over the lower surface 88 of the bladder bar 28 within the central zone 66. The fourth type of openings 88 is of the "non-angled type" and may be round, square or triangular. slippery, and can, if round slippery, typically have a diameter of 1 to 10 mm. In one example, the fourth type of aperture 88 is a round hall with a diameter of 5 mm which blows hot air neat to form the air rivers VD shown in Fig. 2.
    In a manner similar to that described above with reference to the central zone 58, it is possible to calculate a fourth degree of perforation for the central zone 66. The degree of perforation of the central zone 66 is typically 0.5-3.0%. In one example, with the fourth type of aperture 88 having a diameter of 5 mm, the fourth degree of perforation of the central zone 66 is 1.5%.
    The first upper zone 60 of the first upper blow dance 28 has no openings ails. A fifth degree of perforation of the first side zone 60 is therefore 0%. Consequently, the fifth degree of perforation having the first side zone is less than the fourth degree of perforation of the central zone 66. Similarly, the second side zone 62 of the first upper blast layer 28 has no openings ails. Accordingly, a sixth degree of perforation of the second side zone 62 is less than the fourth degree of perforation of the central zone 66. In accordance with an alternative embodiment, the first and / or the second side zone 60, 62 may be provided with apertures, for example round apertures of such size and to such an extent that the first and / or the second side zone 60, 62 still have a lower degree of perforation than the central zone 66.
    During operation of the drying barn 1, the first upper blowing barn 28 is supplied with drying air DA2. Since the degree of perforation of the first and second side zones 60, 62 is lower than the degree of perforation of the central zone 66, a fourth relative air flow is biased, in the unit: m3 of air per hour and mm2 of area lower surface 86, toward the web 18 through the openings 88 of the central zone 66 to be higher than a fifth relative air flow of the side zones 60, 62. This results in a reduced drying action of the side zones 60, 62 at the edges 82, 84 of the web 18, which at least partially compensates for the increased drying action caused by the first lower blow dance 26. side zones 52, 54, as described above. Such compensation, with reduced drying action at the side zones 60, 62 of the upper blast layer 28, 62 reduces the risk of the web 18 being over-dried near its side edges 82, 84 which can give quality problems. Furthermore, the forces pushing the web 18 downward toward the first lower bladder bar 26 decrease slightly at the edges 82, 84 because no airflow is biased away from the side zones 60, 62, further improving the "floating" travel of the web 18.
    The side zones 60, 62 may typically extend below the web 18 a distance DZ1 and DZ2 of approximately 50 to 600 mm from the respective side edges 82, 84, respectively. 100 to 950 mm. The central zone 66 has a width LC which depends on the width WB of the blower bar 28 and on the width of the side zones 60, 62 between which the central zone is located.
    According to an alternative embodiment, a first upper blowing barn may be arranged to have a single zone of openings through which drying air is biased towards the web 18. Such an alternative first upper blowing barn would not involve flake compensation for the 6th drying effect of the lower blowing barn 26 side zones 52. , 54.
    The second upper blowing barn 34 of the second drying deck 30 of the second drying zone 6 shown in Fig. 1 may have a similar construction as the first upper blowing barn 28 shown in Fig. 5. Fig. 6 is a top view of the second lower blowing barn 32. seen in a similar perspective to the first lower bladder bar 26 in Fig. 4. The second lower bladder bar 32 has an upper surface 168 which is arranged to be water towards the web 18 and is divided into a first side zone 152 arranged adjacent to a first spirit 146 of blister 32, a second side zone 154 disposed adjacent to a second spirit 156 of blister 32, and a central zone 158 disposed between the first and second side zones 152, 154. Accordingly, the first and second side zones 152, 154 are disposed on opposite sides of the bladder. the central zone 158.
    The central zone 158 is provided with a fourth type of air bubble openings 172 distributed over the upper surface 168 of the blow mold 32 within the central zone 158. The fourth type of openings 172 is of the "non-angled type" and may, for example, be round, square or triangular hall. The fourth type of Openings 172, if they are round slippery, can typically have a diameter of 1 to 10 mm. In one example, the fourth type of aperture is 172 round slides with a diameter of 2.5 mm.
    The degree of perforation of the central zone 158 is typically 0.5-3.0%. In one example, the perforation rate of the central zone 158 is 1.5%. For example, for an area of 4000 mm 2 of a representative portion 178 of the upper surface 168 within the central zone 158, and with a degree of perforation of 1.5%, the total area of the openings 172 becomes 60 mm 2. A total area of 60 mm2 and a diameter of each opening 172 of 2.5 mm would correspond to approximately twelve openings 172, each having an opening area of approximately 4.9 mm2.
    The first side zone 152 is provided with a fourth type of air bladder openings 172 distributed over the upper surface 168 of the lower bladder shaft 32 within the first side zone 152. The fourth type of openings 172 of the first side zone 152 may be of similar size and shape to the first side zone 152. the openings 172 of the central zone 158 Consequently, the fourth type of openings 172 having the first side zone 152 may, for example, be round slides with a diameter of 2.5 mm.
    The degree of perforation of the first side zone 152 can typically be 0.83.5%. In one example, the degree of perforation has the first side zone 152 is 2.0%. Consequently, the degree of perforation of the first side zone 152 is greater than the degree of perforation of the central zone 158. In one embodiment, the degree of perforation of the first side zone 152 is a factor of 1.1-2.0, preferably 1.1-1.7. the degree of perforation of the central zone 158. For example, for an area of 4000 mm2 of representative portion 179 of the upper surface 168 within the first side zone 152, and with a degree of perforation of 2.0%, the total area of the openings 172 becomes 80 mm2. A total area of 80 mm2 and a diameter of each aperture 172 of 2.5 mm would correspond to about sixteen apertures 172, each having an aperture area of about 4.9 mm 2. Accordingly, the first side zone 152 has a different number of bladder openings 172 per m2 of upper surface 168 blown than the central zone 158. In this embodiment, the first side zone 152 has more bladder openings 172 per m2 of upper surface 168 blown than the central zone 158. The first side zone 152 bladder openings 172 are aligned with a sample that differs from the pattern that the central zone 158 bladder openings 172 are aligned with. the side zone 152 openings 172.
    The second side zone 154 may have a construction similar to the first side zone 152. Accordingly, the second side zone 154 includes, in an example, fourth type openings 172 which are round and have a diameter of 2.5 mm, resulting in a degree of perforation of the fourth side zone 154. other side zone 154 of 2.0%. Consequently, the degree of perforation of the second side zone 154 is greater than the degree of perforation of the central zone 158.
    The openings 172 in the second lower bladder bar 32 have the same size and shape in all zones, but the concentration of openings 172, i.e. the number of openings per surface 168, is higher in the side zones 152, 154 than in the central zone 158, which means that the side zones 152, 154 has a higher degree of perforation.
    During operation of wiper blade 1, wiper air DA3 is supplied to the second lower blower blade 32. The average distance, or height H1, between the underside of the web 18 and the upper surface 168 of the second lower blower blade 32 is typically 2-8 mm in operation. Since the openings 172 of the central zone 158 form a first type of perforation, which differs from a second type of perforation formed by the openings 172 of the side zone 152, air may be blown from the openings 172 of the central zone 158 in a first river pattern which differs. Than a second river sample in which air is carried Than side zone 152 openings 172. Because the degree of perforation of the first and second side zones 152, 154 is greater than the degree of perforation of the central zone 158, there is a first relative air flow, in the unit: m3 air per hour and mm2 of area owe surface 168 which is biased towards the web 18 through the openings 172, the central zone 158 has to be smaller than a second relative air flow, in m3 area per hour and mm2 of area upper surface 168, which is biased towards the web 18 through openings 172 has it first and second side zones 152, 154, which results in an improved lifting force on the web 18 at the side zones 152, 154, i.e. an improved lifting force adjacent the side edges 82, 84 of the web 18 so that the path "floats" in the desired way.
    Each side zone 152, 154 may typically extend a distance DZ3 and DZ4, respectively, of approximately 50 to 600 mm below the web 18 from the side edge 82, 84, respectively. The first and second side zones 152, 154 preferably have a respective total width LZ3, LZ4, seen from the respective spirit 146, 156 of 100 to 950 mm.
    The distance DZ3 and DZ4, respectively, of the second lower bladder bar 32 may be the same or different than the distance DZ1 and DZ2 of the first lower bladder barrel 26, respectively.
    Fig. 7a is a top view of an alternative second blowing barn 232 seen in a similar perspective to the second lower blowing barn 32 in Fig. 6. The alternative second lower blowing barn 232 has an upper surface 268 which is arranged to be water towards the web 18 and is divided into a first side zone 252 disposed adjacent a first portion 246 of the bladder bar 232, a second side zone 254 disposed adjacent a second portion 256 of the bladder bar 232, and a central zone 258 disposed between the first and second side zones 252, 254.
    The central zone 158 is provided with a fourth type of air bubble openings 172 distributed over the upper surface 268 of the blow ring 232 within the central zone 258. The fourth type of openings 172 are of the "non-angled type" and may, for example, be round, square or triangular hall. In one example, the fourth type of Openings is 172 round slides with a diameter of 3.0 mm.
    The degree of perforation of the central zone 258 is typically 0.5-3.0%. In one example, the perforation rate of the central zone 258 is 1.5%.
    The first side zone 252 is provided with a first type of air bubble openings 70, which are of the "angled type" which may, for example, be of a type sometimes referred to as "eyelid openings" and which are arranged in the upper surface 268. The eyelid openings 70 , which may have a construction similar to the openings called "eyelid perforations 6" in WO 97/16594, and which are described with reference to Fig. 2 and Fig. 3 in WO 97/16594, in that the hot drying air is thereby biased by a slope .
    The degree of perforation of the first side zone 252 is typically 0.5-3.0%. In one example, the degree of perforation of the first side zone 252 is 1.5%. Accordingly, the degree of perforation having the first side zone 252 is the same as the degree of perforation of the central zone 258.
    For example, for a surface of the representative portion 278 of 4000 mm 2 of the upper surface 268 within the central zone 258, and a surface of the representative portion 279 of 4000 mm 2 of the upper surface 268 within the first side zone 252, and having a degree of perforation of 1.5%, the total area of the openings 170 and 70, 60 mm2, respectively, in each representative portion becomes 278, 279.
    In alternative embodiments, the degree of perforation of the first side zone 252 may be either greater or less than the degree of perforation of the central zone 258.
    The second side zone 254 may have a construction similar to the first side zone 252. In the alternative second lower bladder bar 232, the side zones 252, 254 have the same degree of perforation as the central zone 258, but different perforation patterns, with apertures 172 of the non-angled type in the central zone 258 and angles 70 of angled type in the side zones 252, 254.
    Each side zone 252, 254 may typically extend the distances DZ3 and DZ4, respectively, which are within the same range as the distance DZ3, DZ4 described above with reference to the bladder bar 32, into below the web 18. Similarly, the first and second side zones 252, 254 may have total widths LZ3 and LZ4, respectively, which lie within similar ranges as the total widths LZ3, LZ4 described above with reference to the blast barn 32. During operation, drying air DA4 is supplied to the second lower blast barn 232. Since the openings 172 of the central zone 258 form a first type of perforation, which differs from a second type of perforation formed by the openings 702 of the side zone 252, air will be blown from the openings 172 of the central zone 258 in a first river sample different from a second river sample in which air is bias Than side zone 252 openings 70. Air cushions which provide improved lifting forces on the web 18 at the side zones 252, 254, i.e. an improved lifting force acting on the web 18 adjacent thereto side edges 82, 84 so that the web "floats" in the intended manner, is formed due to the arrangement with the openings 702, 254 of the side zones 252, 254.
    Fig. 7b and Fig. 7c show the arrangement of Fig. 7a with the openings 702 of the first side zone 252 in more detail, where Fig. 7b is an enlarged view from above, and Fig. 7c shows a cross section along the line VlIc-VIIc in Fig. 7b. The second side zone 254 may have a similar construction as the first side zone 252. As shown in Fig. 7b, the openings 70 are of the angled type, for example of the above-mentioned open lid type openings, and aligned in a first row 273 adjacent a first side 274 of blasladan 232, and in a second row 275 adjacent a second side 276 of blasladan 232. through the side zone 252 the openings 70 are aligned so that the habit opening 70 in the first row 273 is opposite a 6 opening 70 in the second row 275. Consequently "collides" air which is inclined obliquely to the openings 703 of the first row 273, as shown by the arrows IUI, with air which is inclined obliquely than opposite openings 70 in the second row 275, which is indicated by the arrows IU2. Such a collision between the air rivers IUI and IU2 above the center of the upper surface 268 of the bladder bar 232 produces a static pressure Pstat which lifts the web 18 in Fig. 7a at the side zones 252, 254, so that the web 18 "floats" in the desired manner, as shown bast of Fig. 7c.
    Fig. 7d and Fig. 7e show an alternative first side zone 352 and a portion of a central zone 358 of a further alternative lower bladder bar 332, where Fig. 7d is an enlarged view from above and Fig. 7e is a cross section along the line Vile-Vile in Fig. 7d. It will be appreciated that the lower bladder bar 332 may be provided with two side zones arranged on opposite sides of the central zone 358, although this is not shown in the drawings. The further alternative bladder barrel 332 comprises a central ridge 377 arranged in an upper surface 368 of the bladder barrel 332. The ratchet 377 is provided with a first side cradle 373 and a second side cradle 375. Bladder openings 370 of angled type are arranged in the side cradles 373, 375 of the groove 377. In the central zone 358, the openings 370 are arranged in the first and second side cradles 373, 375 in an alternating manner. In addition, the central zone 358 is provided with apertures 372 of the non-angled type arranged in a horizontal portion of the upper surface 368. The side zone 352 has no such apertures of the non-angled type. Apertures 370 aligned with the first side cradle 373 of the ridge 377 in the side zone 352 are aligned with apertures 370 of the second side cradle 375 of the spar 377. Air biased obliquely, as shown by arrows IUI, to "collide" with air which is biased in an angular manner, which is indicated by arrows IU2, from the opposite openings 370 in the second side cradle 375. 352 which acts as an air cushion to lift the web 18 at the side zones 352 so that the web 18 "floats" in the intended manner.
    The degree of perforation of the central zone 358 is typically 0.5-3.0%. In one example, the degree of perforation of the central zone 358 is 1.5%. The degree of perforation of the side zone 352 is typically 0.4-2.7%. Since the side zone 352 in this embodiment is not provided with any openings 372 of the angled type, the degree of perforation of the side zone 352 is lower than the degree of perforation of the central zone 358. In one example, the degree of perforation of the central zone 358 is 1.5 `) / 0 and the degree of perforation of the side zone is 1.3%. Has the alternative second lower bladder bar 332, the side zone 352 has a lower perforation margin than the central zone 358, and another perforation pattern. Consequently, a first relative flow biased by the apertures 370, 372 of the central zone 358 is greater than a second relative flow biased by the apertures 370 of the side zone 352.
    It will be appreciated that many variants of the embodiments described above are possible within the scope of the appended claims.
    It has been described above that the drying barrel 1 comprises a first drying zone 4 and a second drying zone 6 which comprises different kinds of lower blowing barrels 26 23 and 32, respectively. following drying zones where everyone can have the same or different types of drying pads. Furthermore, a drying rack can also be constructed with a single drying zone which comprises a kind of drying pads. According to such an alternative embodiment, a drying hut may be constructed with a single drying zone and comprise only lower blowing ladders 26 of the type described above with reference to Fig. 4. According to a further such alternative embodiment, a drying hut may be constructed with a single drying zone and comprise only lower blades 32 of the type described above with reference to Fig. 6.
    It has been described above that the upper blow blades 28 of the soft as described above with reference to Fig. 5 can be used in both the first and the second drying zone 4, 6. It is understood that also other types of upper blow blades 28 can be used in one or more of these drying zones 4, 6. Furthermore, it is also possible to use as an upper blowing barn in one or more of the drying zones an upper blowing barn which is not zoned along its length. With such a non-zoned upper bladder, flake compensation for the higher drying action in the side zones 52, 54, 152, 154 of the lower bladders 26, 32 will not be achieved, but it may be acceptable in some cases.
    It has been described above that the first drying zone 4 comprises only lower blowing barns 26 of the type described with reference to Fig. 4, and upper blowing barns 28 of the kind described with reference to Fig. 5, it is true that the second drying zone 6 only comprises lower bladders 32 of the type described with reference to Fig. 6, and upper bladders 34 similar to the upper bladders 28 described with reference to Fig. 5. It will be appreciated that other combinations are also possible, for example to use a combination of first lower blowers 26 and other lower blowers 32 in one and the same drying deck of a drying zone. For example, a drying deck may be arranged so that every second lower blowing barn is a first lower blowing barn 26 and every other lower blowing barn is a second lower blowing barn 32.
    It has been described above that the size of the openings in the central zone 58 and the side zones 52, 54 may be different, as described with reference to Fig. 4, or that the concentration of openings per m2 of area of the 24 central zone 158 and of the side zones 152, 154 may be different, as described with reference to Fig. 6. It will be appreciated that in a side zone it is also possible to use both a different size and concentration of apertures, in relation to the central zone. Furthermore, in a side zone it is also possible to use openings which have a different shape in relation to the openings in the central zone. For example, round apertures can be used in the central zone and square apertures can be used in the side zone.
    It has been described above that the upper and lower blowing blades 26, 28, 32, respectively, extend along the entire width WW of the web 18, so that drying air is supplied from a spirit 46, 50, 148 located near a first side edge 82 of the web 18. It will be appreciated that it would also be possible to arrange, as an alternative to a full-length blast barn, two blast barns where each has about half the width 18 of the web 18 and stack Than each of the two side edges 82, 84 of the web 18 and adjacent to each other at the web central part, with air supplied at the openings adjacent to each of the edges 82, 84. Each such half-length bladder would then have a central zone and a first side zone arranged below the respective edge 82, 84 of the web 18.
    It has been described above that the gas supplied to the blow racks 26, 28, 32 is air. It is understood that in some special cases the gas may be a different type of gas, for example air mixed with combustion gases.
    It has been described above that an airbag effect is achieved by the airflow awn biases through adjacent bladder openings 70, 370 in the bladder 232, 332 side zones 252, 352 "colliding" with each other so that a static pressure Pstat is provided. It will be appreciated that an air cushion effect can also be achieved with other arrangements of openings.
    It has been described above that a second relative air flow biased by the openings 70, 32 of the respective side zones 252, 352 is equal to or less than a second relative air flow biased by the respective central zone 258, 358 openings 170, 370, 372. It will be appreciated that it can often be possible to achieve the intended air cushion effect by also supplying a second relative air flow supplied by the side zones 252, 352, which is larger than the first relative air flow supplied by the central zone 258, 358.
    In summary, a drying tray for drying a web 18 of cellulosic pulp comprises a lower blowing barn 26 which is arranged to blow gas upwards towards the web 18 of cellulosic pulp via blowing openings, for drying the pulp according to the principle of airborne web. The lower bladder bar 26 includes a central zone 58 comprising bladder openings 70, 72 of a first perforation type, and at least one first side zone 52 comprising bladder openings 70, 80 of a second perforation type, the second perforation type being different from the first perforation type.
    权利要求:
    Claims (26)
    [1]
    A drying tray for drying a web (18) of cellulosic pulp, the drying tray (1) comprising lower blowing ladders (26; 32) which are adapted to blow gas upwards towards the web (18) of cellulosic pulp via bubble openings, for drying the pulp according to the principle with airborne web, it can be ascertained that the drying barrel (1) comprises at least one lower blowing barrel (26; 32) which comprises, seen in a horizontal direction perpendicular to a direction (P) in which the web (18) is to move over the lower blasladan (26; 32); i. a central zone (58) comprising bladder openings (72) of a first perforation type, and at least one first side zone (52) comprising bladder openings (80) of a second perforation type, the second perforation type differing than the first perforation type.
    [2]
    The dryer according to claim 1, wherein the lower bladder (26, 32) further comprises a second side zone (54) comprising bladder openings (80) of a third perforation type different from the first perforation type of the central zone (58), the central zone (58) is arranged between the first side zone (52) and the second side zone (54).
    [3]
    A dryer according to any one of the preceding claims, wherein the bladder openings (72) of the central zone (58) of the lower bladder (26; 32) have a first degree of perforation, and the bladder openings (80) of said lower side zone of the lower bladder (26; 32) (52) has a second degree of perforation, the second degree of perforation being greater than the first degree of perforation, preferably a factor of 1.1-2.0 greater than the degree of first perforation.
    [4]
    A drying tray according to any one of the preceding claims, wherein the drying tray further comprises at least one upper blowing tray (28) comprising, seen in a horizontal direction perpendicular to a direction (P) in which the web (18) is to move below the upper blowing tray (28). ): A central zone (66) comprising bladder openings (88) having a fourth degree of perforation, and 2. at least one first side zone (60) having a fifth degree of perforation, the fifth degree of perforation being less than the fourth degree of perforation.
    [5]
    The dryer according to claim 4, wherein said upper blast barn (28) further comprises a second side zone (62) having a sixth degree of perforation less than the fourth degree of perforation of the central zone (66), said central blast barn (28) central zone (28) 66) is arranged between the first side zone (60) and the second side zone (62).
    [6]
    A dryer according to any one of the preceding claims, wherein the first side zone (252; 352) of the lower bladder dance (232; 332) comprises bladder openings (70; 370) arranged to form an air cushion above the side zone (252; 352) for lifting the web (252; 352). 18) of cellulose pulp adjacent to its side edge (82).
    [7]
    The dryer according to claim 6, wherein the first side zone (252; 352) further comprises two rows (273; 275) with angled type bubble openings (70; 370) arranged to blow the air stream (IU1; IU2) towards each other.
    [8]
    A dryer according to any one of the preceding claims, wherein the first side zone (52; 152) of the lower blast layer (26; 32) has a width (LZ1, LZ3), seen in the horizontal direction which is perpendicular to a direction (P) in which the web 25 (18) should move over the lower bladder bar (26; 32), of 100 to 950 mm.
    [9]
    A dryer according to any one of the preceding claims, wherein the first side zone (52; 152) of the lower blast layer (26; 32) is arranged to extend below the web (18) a distance (DZ1; DZ3) of approximately 50 to 600 mm from a side edge (82) of the web (18).
    [10]
    A drying tray according to any one of the preceding claims, wherein the drying tray comprises a first drying zone (4) comprising a first type of lower blowing barrels 28 (26), and a zone following the following second drying zone (6) comprises a second type of lower blowing barrels ( 32).
    [11]
    Tried according to any one of the preceding claims, wherein at least some of the bladder openings (80) of the first side zone (52) have a different size than the bladder openings (72) of the central zone (58).
    [12]
    A dryer according to any one of the preceding claims, wherein the first side zone (52) has a different number of bladder openings (80) per m2 of bladder surface 10 (168) than the central zone (158).
    [13]
    A dryer according to any one of the preceding claims, wherein at least one of said at least one lower bladder (26; 232; 332) comprises a mixture of angled type blades (70; 370) and non-angled bladders (72; 172). ; 372).
    [14]
    A drying tray according to any one of the preceding claims, wherein at least one of said at least one lower bladder tray (32) comprises only bladder openings of non-angled type (172).
    [15]
    A drying tray according to any one of the preceding claims, wherein the drying tray comprises at least one drying deck (24; 30) in which at least 90% of the total number of lower blades (26; 32) of that drying deck comprises the central zone (58; 158) and the first side zone (52; 152).
    [16]
    A method of drying a web (18) of cellulosic pulp by means of lower blowing ladders (26; 32) arranged to blow gas upwards towards the web (18) of cellulosic pulp via blowing openings, in order to dry the pulp in accordance with the principle of airborne web cans. by using at least one lower bladder (26; 32) which comprises, seen in a horizontal direction perpendicular to a direction (P) in which the web (18) is to move over the lower bladder (26; 32), a central zone (58) 29 including bubble vents (70, 72), and at least one first side zone (52) comprising bubble vents (70, 80), blowing a first relative gas flow in a first river sample toward the web (18) through the central vents of the central zone (58). (70, 72), and blow a second relative gas flow in a second river sample, which differs from the first river sample, toward the path (18) through the bubble openings (70, 80) of the first side zone (52).
    [17]
    The method of claim 16, further comprising using in said lower bladder bar (26; 32) a second side zone (54) comprising bladder openings (70; 80), the central zone (58) being disposed between the first side zone (52) and the second side zone (54), and blow a third relative gas flow in a third river sample, which differs than the first flow pattern, toward the path (18) through the blow openings (70, 80) of the second side zone (54).
    [18]
    A method according to any one of claims 16-17, wherein the second relative gas flow is greater than the first relative gas flow, wherein the second relative gas flow is preferably a factor of 1.1-2.0 greater than the first relative gas flow.
    [19]
    A method according to any of claims 16-18, further comprising blowing the second relative gas stream in a second river sample towards the web to form an air cushion for lifting a side edge (82) of the web 25 (18) of cellulosic pulp.
    [20]
    A method according to any of claims 16-19, further comprising using at least one upper bladder (28) comprising, viewed in a horizontal direction perpendicular to a direction (P) in which the web (18) is to move below the upper blowing barn (28), a central zone (66) comprising blowing openings (88), and at least one first side zone (60), and blowing a fourth relative gas flow toward the web through the blowing openings (88) of the central zone (66), and blowing a fifth relative gas flow, which is below the fourth relative gas flow, toward the path through the first side zone (60).
    [21]
    A drying tray for drying a web (18) of cellulosic pulp, wherein the drying pad (1) comprises lower blowing ladders (26; 32) which are adapted to blow gas upwards towards the web (18) of cellulosic pulp via blowing openings (70, 72). , and at least one upper blowing barn (28) which is arranged to blow gas neatly against the web (18) of cellulosic pulp via blowing openings (88), for drying the pulp according to the principle of airborne web, characterized in that said at least one upper blowing barn (28 ) comprises, seen in a horizontal direction perpendicular to a direction (P) in which the web (18) is to move under the Upper blast barn (28); i. a central zone (66) comprising bladder openings (88) having a fourth degree of perforation, and ii. at least one first side zone (60) having a fifth degree of perforation, the fifth degree of perforation being less than the fourth degree of perforation, so that the drying action of the first side zone (60) is lower, the drying action of the central zone (66) of said at least one upper blaslada (28).
    [22]
    22. CI 0 0 0 0 0 0 0 0 0 OD CD (ICID CD CD CD OD CDCDCDflDflDCDCDCD CD flID CD ID CD thi CD CD CD CID CD OD CD OD CID II lB CD Ci.
    [23]
    23. ICD CD 11 CD CD CD CD CD CID CD CD CID D CD CID CD CID (ID CDII BID CD CD CD CID CD CID CD CD CD D CD OD OD CD OD (ID CD CD CD (1D Cli (11: 1 CD CD (ID CD OD CD D OD CD OD CID CD CD OD OD OD CD 013 CID CD OD CID OD OD CID P PP EP CD CD
    [24]
    24. 0. [.) CD UP UP CD OP CD (P.
    [25]
    25. UP !, CP. CP.
    [26]
    26. CD CD GD C CD POD OD CID CID CID CD OD CD CID CD CD CD CD CD CD CD CU CID CD 1010 CID CID CD CD 1D CID CD fID CD (103 CO CD OD OD OD CD CD ED ED CID CID OD CD CD CD CD CD 1003 100 CID OD CD CID OD OD CD CID CID CID OD OD (101 (I CD CD CD (1D CD OD OD CD (1)) CD CD CD CID CD CID OD OD Q .. ---- 24 28 28 28s 28 VDVD 18 IUIUIU IU 2626SIU 26S S 26
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    FI64397B|1983-07-29|TORKANORDNING FOER SKINN
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    同族专利:
    公开号 | 公开日
    BR112014014521A2|2017-06-13|
    DE112012005278T5|2014-10-23|
    FI128539B|2020-07-31|
    CL2014001538A1|2014-12-19|
    CN104114967A|2014-10-22|
    CA2859146C|2020-08-18|
    SE537252C2|2015-03-17|
    BR112014014521B1|2021-06-15|
    FI20145514A|2014-06-05|
    CN104114967B|2016-03-09|
    WO2013089629A1|2013-06-20|
    CA2859146A1|2013-06-20|
    引用文献:
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    US2848820A|1952-10-08|1958-08-26|Svenska Flaektfabriken Ab|Method and apparatus for supporting and conveying web-like material|
    SE393826B|1974-05-29|1977-05-23|Svenska Flaektfabriken Ab|ARRANGEMENTS THAT WHEN TRANSPORTING A BAN OR SHEET OF AIR-SUPPORTED MATERIAL, IN FRONT OF THE MATERIAL IN A FIXED STABLE FLOATING THROUGH ONE OR SEVERAL FLOORS OF A TREATMENT PLANT, ONE ...|
    US4021931A|1975-11-21|1977-05-10|Midland-Ross Corporation|Air circulating apparatus for floating material in web form|
    SE450644B|1985-01-16|1987-07-13|Flaekt Ab|DEVICE USED FOR A DRYING OF A MATERIAL INTENDED FOR PLANT|
    US5259124A|1988-06-15|1993-11-09|Poterala Robert J|Open top compact dryer oven for a web|
    US5471766A|1993-03-18|1995-12-05|Valmet Paper Machinery, Inc.|Method in contact-free air-drying of a material web as well as a nozzle-blow-box and a pulp dryer that make use of the method|
    SE505113E|1995-10-31|2000-03-08|Flaekt Ab|Blow box for use in a plant for drying a web of material|
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    EP2053663A1|2007-10-25|2009-04-29|Applied Materials, Inc.|Hover cushion transport for webs in a web coating process|
    CN201395742Y|2009-03-27|2010-02-03|谢放华|High-efficiency drying blow box for paper-making production|CN106012645B|2016-07-31|2019-04-23|山东泓联特种纸科技有限公司|Papermaking drying machine drying section|
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    KR102146530B1|2016-10-24|2020-08-20|주식회사 엘지화학|Dryer|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1151199A|SE537252C2|2011-12-15|2011-12-15|Drying box which has blow boxes for drying a web of cellulose pulp|SE1151199A| SE537252C2|2011-12-15|2011-12-15|Drying box which has blow boxes for drying a web of cellulose pulp|
    PCT/SE2012/051393| WO2013089629A1|2011-12-15|2012-12-14|A cellulose pulp drying box having blow boxes|
    CN201280069698.1A| CN104114967B|2011-12-15|2012-12-14|There is the cellulose pulp drying box of blow box|
    DE112012005278.1T| DE112012005278T5|2011-12-15|2012-12-14|Pulp drying box with blow boxes|
    CA2859146A| CA2859146C|2011-12-15|2012-12-14|A cellulose pulp drying box having blow boxes|
    FI20145514A| FI128539B|2011-12-15|2012-12-14|A cellulose pulp drying box having blow boxes and a method for drying a web of cellulose pulp|
    BR112014014521-0A| BR112014014521B1|2011-12-15|2012-12-14|PULP PULP DRYING BOX FOR DRYING A PULP PULP BLANKET, AND DRYING METHOD OF A PULP BLANKET|
    CL2014001538A| CL2014001538A1|2011-12-15|2014-06-11|A cellulose pulp drying box for drying a cellulose pulp web, comprises lower blow boxes comprising at least one lower blow box with a central area with blow holes forming a first type of perforation, at least one first lateral zone comprising blow holes forming a second type of perforation; and associated method.|
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