JP2018523087A - Nozzle box for drying continuous paper sheets - Google Patents

Abstract

Nozzle box that blows out hot gas into the convection drying area of the equipment for continuous drying of paper sheets transported by airflow, at least one direct impingement that jets a hot gas jet perpendicular to the average plane of the paper sheet to be dried A nozzle is provided. The nozzle box includes a plurality of inclined injection nozzles that eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried. At least two inclined injection nozzles are provided in which the plane containing the vector representation of the injection direction of the at least two inclined injection nozzles does not include a vector that directly represents the injection direction of the collision nozzle.

Description

  The present invention relates to the technical field of nozzle boxes for continuous airflow (or floating) paper sheet drying equipment. The invention further relates to a facility for continuous airflow drying of paper or paperboard sheets comprising such a nozzle box and a method of operating such a facility.

  Airflow conveyance or (floating) paper or paperboard sheet drying by convection drying or by a combination of radiation drying and convection drying is known. Paper sheets, such as coated paper sheets, are carried or suspended by hot air used for drying, without the side edges of the paper sheet being mechanically held in the drying chamber. Such a drying system must provide efficient drying and accurate floating by airflow conveyance of the paper sheet conveyed through the drying system.

  U.S. Pat. No. 3,823,488 discloses a flotation dryer. An apparatus for guiding an expanded material web in a floating state by means of a fluid cushion includes a plurality of nozzle boxes located adjacent to each other in a direction parallel to a plane in which the material web is disposed. In the nozzle box, respective injection nozzles inclined in the transverse direction with respect to the traveling direction of the web are formed. The return flow path is provided to remove the fluid blown to the web from the injection nozzle. The return flow path is alternately arranged with the nozzle box in the web traveling direction. The return channel is an open gap defined by each adjacent nozzle box. The inclined spray nozzles are arranged on both sides of each return flow path. The inclined nozzle can be a slot nozzle or a hole nozzle. In addition to the inclined jet, the drying performance can be further improved if the jet is also directed perpendicular to the material web and / or the opposing nozzle box.

  U.S. Pat. No. 6,598,315 B1 discloses a nozzle arrangement in an airflow web drying apparatus for drying coated paper webs and the like. The nozzle array includes at least one overpressure nozzle that is disposed so as to blow dry air in both the traveling direction of the web and the direction opposite to the traveling direction of the web. The nozzle arrangement further comprises a direct impingement nozzle coupled to the outlet side and / or the inlet side of the overpressure nozzle. The direct impingement nozzle is formed with a plurality of nozzle slots or nozzle holes to blow dry air vertically toward the web. The vertical distance from the nozzle surface of the direct impingement nozzle to the web is greater than the vertical distance from the support surface of the overpressure nozzle. A discharge passage is provided between the nozzle arrays continuous in the traveling direction of the paper web in order to discharge wet air. A series of nozzle arrangements between the discharge passages are provided both above and below the paper web being conveyed. The generated air flow causes the paper web to undulate in the paper web conveyance direction.

  It is an object of the present invention to disclose a nozzle box for use in continuous paper sheet or paperboard drying equipment that provides more efficient paper drying. It is an object of the present invention to disclose a convection drying facility comprising such one or more nozzle boxes that provides more efficient paper drying.

  A first aspect of the present invention is a nozzle box that blows out a high-temperature gas into a convection drying region of a facility for continuous drying of a paper sheet that is conveyed by air flow, for example, a continuous drying of a coated paper sheet that is conveyed by air flow. . In the context of the present invention, the term “paper sheet” should be understood as including paperboard. Preferably, the nozzle box is provided so as to be installed across the width of the continuous drying facility. The nozzle box comprises at least one direct impingement nozzle that ejects a jet of hot gas perpendicular to the average plane of the paper sheet to be dried. The nozzle box includes a plurality of inclined injection nozzles that eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried. Multiple means at least two. The nozzle box comprises at least two inclined injection nozzles in which the plane containing the vector indication of the injection direction of the at least two inclined injection nozzles does not contain the vector that directly represents the injection direction of the collision nozzle. In this document, the vector indicates the direction in the three-dimensional space of the average jet of hot gas ejected by the nozzle. When relevant, the strength of the vector is equal to the jet impact of the nozzle when the nozzle is in use. A vector should be considered independent of its origin in the sense that the vector can be placed at another origin while maintaining the direction of the vector in three-dimensional space. Evaluate whether or not three vectors (a vector representing the injection direction of the collision nozzle and two vectors each representing the injection direction of one of the two inclined injection nozzles) are in one plane. Therefore, the three vectors are placed at the same starting point, and it is observed whether the three vectors when located at the same starting point are located in one plane in the three-dimensional space. Preferably, the nozzle box comprises a plurality of direct impingement nozzles that eject a jet of hot gas perpendicular to the average plane of the paper sheet to be dried.

  The nozzle box of the present invention has been shown to provide more efficient drying when used in a convection drying area within a dryer for continuous drying of paper sheets being air-flowed compared to prior art nozzle boxes. ing. The nozzle box is not dried or held by the mechanical system such as a chain system or pin system, and the edge of the paper sheet is efficiently dried and the paper sheet is accurately produced by the hot gas ejected from the nozzle of the nozzle box. Provide the required combination with the floating. The nozzle box provides a high convective force density. Although the good results with the nozzle box of the present invention are not fully understood, the presence of turbulence in several directions is believed to increase drying efficiency. Furthermore, more uniform drying of the paper sheet conveyed by airflow can be obtained.

  The nozzle may be a direct impingement nozzle or an inclined injection nozzle, for example, provided as a circular hole (or hole) in a plate material or cast metal, as a slot in a plate material or cast metal, or as a frustoconical injection nozzle. it can.

  Preferably, the angle of the injection direction of the inclined injection nozzle with respect to the injection direction of the one or more direct impingement nozzles is 20-75 °, for example 30 °.

  In a preferred embodiment, the inclined injection nozzle is provided as a through hole or a through slit on the inclined surface of the nozzle box, and the through hole or the through slit is perpendicular to the inclined surface.

  Preferably, the nozzle box includes a hot gas chamber. The hot gas chamber is provided for supplying hot gas to be ejected by the collision nozzle and by the inclined injection nozzle to at least one direct collision nozzle and the plurality of inclined injection nozzles.

  In a preferred embodiment, the inclined spray nozzle is provided in a nozzle head attached to a nozzle box. Preferably, the nozzle head is mechanically attached, for example by bolts or rivets in the nozzle box. More preferably, the nozzle head is mechanically replaceably attached to the nozzle box so that the nozzle head can be replaced in the nozzle box. The nozzle head can comprise, for example, a cast metal part, for example provided with a nozzle in the nozzle head by drilling or machining holes and / or slots.

  Preferably, there are at least 3 nozzle boxes (preferably at least 4, more preferably at least 5, more preferably at least 6, more preferably at least 7, more preferably at least 8, more preferably at least 9). Individual, more preferably at least 10, more preferably at least 11, more preferably at least 12, for example 12 inclined spray nozzles, with at least 3 (preferably at least 4, more preferably at least 5) More preferably at least 6, more preferably at least 7, more preferably at least 8, more preferably at least 9, more preferably at least 10, more preferably at least 11, more preferably at least 12, For example, 12) Each having a vector representing the injection direction of each inclined injection nozzle in use, preferably at least 3 (preferably at least 4, more preferably at least 5, more preferably at least 6, more preferably at least 7). Each, more preferably at least 8, more preferably at least 9, more preferably at least 10, more preferably at least 11, more preferably at least 12, eg 12) inclined nozzle vectors, Have different directions in the three-dimensional space.

  In a preferred embodiment, the inclined injection nozzle comprises or consists of a first set of inclined injection nozzles and a second set of inclined injection nozzles. The first set of inclined injection nozzles is provided so as to blow in the first direction, and the second set of inclined injection nozzles is provided so as to blow out in the second direction. The first direction is perpendicular to the second direction. Preferably, the first direction is the paper sheet conveyance direction when the nozzle box is installed in the convection drying region of the equipment for continuous drying of the paper sheet conveyed by airflow. Preferably, the second direction is a direction crossing the transport direction of the paper sheet to be dried when the nozzle box is installed in the convection drying area of the equipment for continuous drying of the paper sheet transported by airflow. is there. More preferably, the inclined injection nozzle includes a third set of inclined injection nozzles and a fourth set of inclined injection nozzles. The third set of inclined injection nozzles is provided so as to blow out in the third direction, and the fourth set of inclined injection nozzles is provided so as to blow out in the fourth direction. Preferably, the inclination angle between the first direction and the third direction is 180 °, and the inclination angle between the second direction and the fourth direction is 180 °.

  Preferably, the nozzle box is provided with a suction opening for gas discharge. The nozzle box can comprise, for example, a circular suction opening for gas discharge and / or a slit-shaped suction opening.

A preferred nozzle box comprises a plurality of nozzle units on the nozzle box. Each of the units
-At least one, preferably a plurality of direct impingement nozzles, jetting a jet of hot gas perpendicular to the average plane of the paper sheet to be dried;
A plurality of inclined injection nozzles, comprising inclined injection nozzles provided to eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried;
There are provided at least two inclined injection nozzles of the nozzle unit in which the plane containing the vector representation of the injection direction of the at least two inclined injection nozzles does not include the vector representing the injection direction of the direct impinging nozzle of the nozzle unit. Preferably, the nozzle unit is provided as a nozzle head attached to a nozzle box. Preferably, the nozzle head is mechanically attached to the nozzle box using, for example, bolts or rivets. Even more preferably, the nozzle head is attached to the nozzle box in a mechanically replaceable manner, for example by means of bolts. Preferably, the suction opening for gas discharge is provided between the nozzle units in the nozzle box. More preferably, the gas suction circular suction opening and / or the slit-shaped suction opening can be provided between the nozzle units in the nozzle box, and the nozzle unit can exist as a nozzle head.

  Preferably, when a nozzle unit and / or nozzle head is used, the nozzle unit or nozzle head comprises a hot gas chamber. The hot gas chamber is provided to supply the hot gas to be ejected by the direct collision nozzle and by the inclined injection nozzle to at least one direct collision nozzle and the plurality of inclined injection nozzles. Means such as tubes or pipes are provided in the nozzle box for supplying hot gas to the hot gas chamber. More preferably, the hot gas chamber in the nozzle box is arranged to provide hot gas to the hot gas chamber of each of the multiple nozzle units. The nozzle unit can exist as a nozzle head. The nozzle head can comprise, for example, a cast metal part in which the nozzle is provided in the nozzle head, for example by drilling or machining holes and / or slots.

  Preferably, the nozzle units of the nozzle box have the same nozzle configuration. The nozzle unit can exist as a nozzle head.

  In a preferred embodiment, sharp corners of the nozzle unit or nozzle head are avoided to prevent the risk of damaging the paper if an unexpected contact occurs.

  In a preferred embodiment, the nozzle unit is linearly aligned on the nozzle box, and as a result, when installed in the drying device, the nozzle unit is linearly aligned across the width of the drying facility. Provided.

  In a preferred embodiment, the nozzle units are provided in a staggered arrangement on the nozzle box, preferably so that when installed in the drying device, the nozzle units are arranged in a staggered manner across the width of the drying device. Is provided. In an exemplary embodiment, the first, third, and fifth nozzle units in the nozzle box are linearly aligned and the second nozzle unit includes the first nozzle unit and the third nozzle. The fourth nozzle unit is arranged in a staggered manner between the units, and the fourth nozzle unit is arranged in a staggered manner between the third nozzle unit and the fifth nozzle unit. The even-numbered nozzle units are aligned linearly. The odd-numbered nozzle units are aligned linearly, but are in a staggered position as compared with the even-numbered nozzle units. Preferably, at least a part of the nozzle unit includes an inclined injection nozzle whose injection direction is directed toward the space between the nozzle units. Preferably, in such an embodiment, the even-numbered nozzle unit includes an inclined injection nozzle that blows out in the direction of the space between the even-numbered nozzles. And preferably in this embodiment, an odd-numbered nozzle unit is equipped with the inclination injection nozzle which blows off in the direction of the space between odd-numbered nozzles.

  In a preferred embodiment, the number of nozzle units is at least 3 (preferably at least 4, more preferably at least 5, more preferably at least 6, more preferably at least 7, more preferably at least 8, more preferably At least 9, more preferably at least 10, more preferably at least 11, more preferably at least 12, for example 12 inclined spray nozzles, and at least 3 (preferably at least 4, more preferably at least 5, more preferably at least 6, more preferably at least 7, more preferably at least 8, more preferably at least 9, more preferably at least 10, more preferably at least 11, more preferably at least 12 For example 1 Each inclined injection nozzle has a vector representing the injection direction of each inclined injection nozzle in use and is at least 3 (preferably at least 4, more preferably at least 5, more preferably at least 6). , More preferably at least 7, more preferably at least 8, more preferably at least 9, more preferably at least 10, more preferably at least 11, more preferably at least 12, eg 12) Each of the nozzle vectors has a different direction in three-dimensional space.

  When the nozzle unit is present as a nozzle head, the nozzle head preferably comprises a hot gas chamber. The hot gas chamber is provided for supplying hot gas to be ejected by the collision nozzle and by the inclined injection nozzle to at least one direct collision nozzle and the plurality of inclined injection nozzles. Means such as tubes or pipes are provided in the nozzle box for supplying hot gas to the hot gas chamber of the nozzle head. More preferably, the nozzle head comprises a metal body, the metal body at least partially surrounding the hot gas chamber. Even more preferably, the nozzle head is all made of metal.

  When the nozzle unit is present as a nozzle head, preferably the nozzle head comprises a body made of cast metal. Preferably, the impingement nozzle and / or the inclined injection nozzle are provided in the body as perforated or machined holes and / or slots. Preferably, the body at least partially surrounds the hot gas chamber in the nozzle head.

  In a preferred nozzle box with a nozzle unit (possibly the nozzle unit is present as a nozzle head), at least one direct impingement nozzle is provided in the central part of the nozzle unit and the inclined injection nozzle surrounds at least one direct impingement nozzle. . In a preferred embodiment, at least a portion, more preferably all, of the inclined injection nozzles surrounding at least one direct impingement nozzle are provided to blow inward toward the at least one direct impingement nozzle. In a preferred embodiment, the first portion of the inclined injection nozzle surrounding the at least one direct impingement nozzle is provided to blow inward toward the at least one direct impingement nozzle. A second portion of the inclined injection nozzle surrounding the at least one direct collision nozzle is provided to blow away from the at least one direct collision nozzle.

  In a preferred embodiment, the inclined injection nozzles in the nozzle unit are arranged such that the hot gas jets of the inclined injection nozzles lie on a plane that is evenly distributed in the circumferential direction perpendicular to the nozzle box when the inclined injection nozzle is operated. Provided.

  In a preferred embodiment, the nozzle box includes a suction opening for gas discharge, and the nozzle box includes a plurality of nozzle units on the nozzle box. Preferably, the suction opening for gas discharge is provided between the nozzle units in the nozzle box.

  In a preferred embodiment, the nozzle units are provided in a staggered arrangement on the nozzle box, so that when installed in the drying device, the nozzle units are provided in a staggered manner across the width of the drying device. The suction openings or groups of suction openings are also arranged in a staggered manner on the nozzle box and are alternately arranged with the nozzle units.

  In a preferred embodiment, the nozzle box comprises a plurality of nozzle heads. Each nozzle head comprises a plurality (e.g. four) direct impingement nozzles that eject a jet of hot gas perpendicular to the average plane of the paper sheet to be dried. The direct impingement nozzle preferably has several lines in the direction of the nozzle box that coincide with the width direction of the paper sheet to be dried cross only one direct impingement nozzle of the nozzle head, while the paper sheet to be dried The other line in the nozzle box direction that coincides with the width direction crosses the two direct impingement nozzles of the same nozzle head, and the other line in the nozzle box direction that coincides with the width direction of the paper sheet to be dried is the same It is provided so as not to cross the direct impact nozzle of the nozzle head. Such a direct impingement nozzle arrangement has been shown to provide better uniformity of heat transfer to the paper sheet to be dried by the direct impingement nozzle. Preferably, each of the nozzle heads includes one or more inclined injection nozzle rows, and each of the inclined injection nozzle rows includes a number of inclined injection nozzles arranged in a straight line. More preferably, at least one inclined spray nozzle row, for example two inclined spray nozzle rows, is aligned on a line in the direction of the nozzle box that coincides with the width direction of the paper to be dried. In a more preferred embodiment, the two inclined spray nozzle rows are aligned on a line in the direction of the nozzle box that coincides with the width direction of the paper to be dried, and one of the two inclined spray nozzle rows The rows are provided to blow in the direction of movement of the paper sheet to be dried. The other inclined spray nozzle row is provided so as to blow out in the direction opposite to the moving direction of the paper sheet to be dried. More preferably, the nozzle head is additionally at least one row aligned on a line that forms an angle of, for example, 10 ° to 80 ° with the direction of the nozzle box that coincides with the width direction of the paper sheet to be dried. For example, two inclined spray nozzle rows are provided.

  The second aspect of the present invention is a facility for continuous airflow drying of paper sheets, for example coated paper sheets, for example paperboard, for example coated paperboard. The facility includes a nozzle box as shown in the first aspect of the present invention. The nozzle box extends over the width available in the facility for transporting the paper sheet. Preferably, the nozzle unit is provided in the nozzle box over the width available in the equipment for transporting the paper sheet, so that the nozzle in the nozzle unit of the nozzle box, for example the nozzle in the nozzle head, is to be dried. Can accommodate the full width. Preferably, the facility comprises two or more nozzle boxes as shown in the first aspect of the invention. Preferably, the first set of nozzle boxes as shown in the first aspect of the present invention is provided above a plane that can be used for transporting paper sheets, and the second according to the first aspect of the present invention. This set of nozzle boxes is provided below a plane that can be used for transporting paper sheets.

  Preferred equipment comprises an infrared emitter, for example a premixed gas fired infrared emitter row, and a nozzle box as shown in the first aspect of the invention between the row or combination of infrared emitters.

  A preferred facility comprises one or more nozzle boxes. Means are provided for hot gas suction through nozzle openings (e.g. between nozzle units or nozzle heads) and / or between nozzle boxes, e.g. circular suction openings or slit-like suction openings. . Means are provided for collecting the sucked gas into the piping. Preferably, a pipe for discharging a part of the sucked gas from the facility is provided. Means are provided for supplying fresh air into the facility where freshly supplied air is mixed with the inhaled gas. Together with freshly supplied air, at least a part of the sucked-in gas is fed into one nozzle box or several, so as to be sprayed onto the paper sheet to be dried by the nozzle box direct impingement nozzle and by the inclined jet nozzle A pipe for recirculation is provided so as to return to the nozzle box. Means are provided for heating the mixture of inhaled gas and freshly supplied air before supplying it to the nozzle box. Such means can be, for example, a heat exchanger or a gas burner. Such a gas burner can be provided such that the combustion gas of the gas burner is added to the mixture of the sucked-in gas and newly supplied air. Means (for example, a damper) for controlling the gas flow are provided in the pipe.

  In a preferred embodiment, the installation comprises a suction opening for gas discharge. In a preferred embodiment, the installation comprises a number of nozzle boxes in the direction of paper sheet movement and a gas-fired infrared emitter between the nozzle boxes. The suction opening is preferably positioned between the nozzle box and the gas fired infrared emitter.

  In a preferred installation, the one or more nozzle boxes are in the direction opposite to the direction of transport of the paper sheet through the drying facility, the vector sum representing the injection direction and having the injection impact of the inclined injection nozzle of the nozzle box as an intensity. It is provided to point to.

  A preferred facility comprises a number of nozzle boxes as shown in the first aspect of the invention. The at least two consecutive nozzle boxes are staggered by comparing the position of the nozzle unit in the first nozzle box of the two consecutive nozzle boxes with the position of the nozzle unit in the second nozzle box of the two consecutive nozzle boxes. The nozzle unit is arranged in a shape. A series of infrared emitters, more preferably gas fired infrared emitters, are positioned between two successive nozzle boxes. Even more preferably, a suction opening is provided between the nozzle box and the series of infrared emitters for gas discharge.

  A third aspect of the present invention is a method for continuous drying of paper sheets (eg, coated paper sheets, eg, paperboard), and equipment for continuous drying is used as shown in the second aspect of the present invention. The method includes the step of transporting a paper sheet, eg, a coated paper sheet, through the equipment to dry the paper sheet within the equipment for continuous drying, the paper sheet having mechanical means on the side edges of the paper sheet. The paper sheet undulates in the conveying direction of the paper sheet passing through the drying facility, and the paper sheet is perpendicular to the conveying direction of the paper sheet passing through the drying facility. Preferably, the speed of the paper sheet conveyed through the drying equipment is at least 50 m / min, more preferably at least 150 m / min, more preferably at least 300 m / min, preferably 00m / a minute greater. The preferred range is 300～2500M / min, more preferably in the range of 500 to 1500 / min.

  In a preferred method, the vector sum of the vectors representing the jetting direction and having the jetting impact of the inclined jet nozzles of the nozzle box as an intensity refers to the direction opposite to the paper sheet transport direction through the drying facility.

  Preferably, the mass per unit time of the hot gas ejected by the inclined jet nozzle of the flow box in the direction opposite to the movement of the paper sheet is equal to the mass of the hot gas ejected by the inclined jet nozzle of the flow box in the direction of movement of the paper sheet. More than 10%, more preferably more than 20%, more preferably more than 50%, more preferably more than 75% and even more preferably more than 100% of the mass per unit time. Preferably, the mass per unit time of the hot gas ejected by the inclined jet nozzle of the nozzle box in the direction opposite to the movement of the paper sheet is the unit time of the hot gas ejected by the inclined jet nozzle of the nozzle box in the direction of movement of the paper sheet. Less than 150% greater than the hit weight.

FIG. 1 shows an example of a nozzle box as shown in the first aspect of the present invention. FIG. 2 shows a front view of a nozzle head that can be used in the present invention. FIG. 3 shows a rear view of a nozzle head that can be used in the present invention. FIG. 4 shows an example of a nozzle box as shown in the first aspect of the present invention. FIG. 5 shows still another example of the nozzle box as shown in the first aspect of the present invention. FIG. 6 shows a cross-sectional view in the paper transport direction. FIG. 7 shows a cross-sectional view of an example of equipment for continuous airflow conveying drying of a paper sheet comprising a nozzle box as shown in the first aspect of the present invention. FIG. 8 shows a vector representing the jet of one inclined injection nozzle of the inclined injection nozzles of the nozzle box of the installation of FIGS. 6 and 7. FIG. 9 shows another example of a nozzle box as shown in the first aspect of the present invention. FIG. 10 shows an embodiment of an equipment for continuous airflow drying of paper sheets according to the second aspect of the present invention. FIG. 11 shows an embodiment of a nozzle box as shown in the first aspect of the invention. FIG. 12 shows an air drying facility according to the second aspect of the present invention.

  FIG. 1 shows an example of a nozzle box 100 as shown in the first aspect of the present invention. The nozzle box 100 is provided so as to blow high-temperature gas into a convection drying region of equipment for continuous drying of paper sheets (including paperboard) that is air-flowed, for example, continuous drying of coated paper sheets that are air-flowed. And provided to be installed across the width of the continuous drying facility. The nozzle box 100 includes a plurality of nozzle units 105 on the nozzle box. In the example, the nozzle unit 105 is a nozzle head 105 that is removably mounted on the nozzle box 100 by bolts 107 and nuts. It is also possible for the nozzle unit to be formed integrally with the material of the nozzle box. In this example, although not necessarily essential to the present invention, all the nozzle heads of the nozzle box have the same nozzle configuration. The nozzle heads 105 are provided in a staggered manner on the nozzle box. As a result, when installed in the drying device, the nozzle units are provided in a staggered manner across the width of the drying device. In the example, the first, third, and fifth nozzle units in the nozzle box are linearly aligned and the second nozzle unit is between the first nozzle unit and the third nozzle unit. The fourth nozzle units are arranged in a staggered manner between the third nozzle unit and the fifth nozzle unit. The even-numbered nozzle units are aligned linearly. The odd-numbered nozzle units are aligned linearly, but are in a staggered position as compared with the even-numbered nozzle units. The nozzle unit includes an inclined injection nozzle whose injection direction is directed toward the space between the nozzle units. The even-numbered nozzle unit includes an inclined injection port that blows out in the direction of the space between the even-numbered nozzles. The odd-numbered nozzle unit includes an inclined injection port that blows out in the direction of the space between the odd-numbered nozzles. However, other arrangements of nozzle units or nozzle heads in the nozzle box are possible, for example, the nozzle units or nozzle heads can be linearly aligned on the nozzle box, for example, as a result in the drying device. When installed, the nozzle unit is provided in linear alignment over the width of the drying device.

  2 and 3 show a front view (FIG. 2) and a rear view (FIG. 3), respectively, of the nozzle head 105 used in the exemplary nozzle box 100 of FIG. The nozzle head 105 comprises a perforated hole 103 that allows the nozzle head to be replaceably attached to the nozzle box with bolts and nuts. The nozzle head 105 comprises four direct impingement nozzles 108 that eject a jet of hot gas perpendicular to the average plane of the paper sheet to be dried. The nozzle head 105 includes twelve inclined injection nozzles 109, 110, 111, and 112 that are provided so as to eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried. There are provided inclined injection nozzles 109 and 111 in which the plane including the vector display of the injection directions of the inclined injection nozzles 109 and 111 does not include the vector representing the injection direction of the direct collision nozzle 108 of the nozzle unit. On the other hand, the plane formed by the vector display of the injection direction of the inclined injection nozzles 111 and 112 includes a vector representing the injection direction of the direct collision nozzle 108 of the nozzle unit. In the nozzle box head 105, although not essential to the present invention, the direct collision nozzle 108 is provided at the center of the nozzle head 105. The inclined injection nozzles 109, 110, 111 and 112 directly surround the collision nozzle 108. The inclined spray nozzles 109 and 110 are provided so as to blow out directly toward the collision nozzle 108. The inclined injection nozzles 109, 110, 111 and 112 directly surround the collision nozzle 108. The inclined injection nozzles 111 and 112 are provided so as to blow out in a direction away from the collision nozzle 108 directly.

  A hot gas chamber 122 is provided inside the nozzle head 105 (see FIG. 3). The hot gas chamber is provided for supplying hot gas to be ejected by the collision nozzle and by the inclined injection nozzle to at least one direct collision nozzle and the plurality of inclined injection nozzles. The hot gas chamber in the nozzle box is arranged to provide hot gas to the air chamber of each of the multiple nozzle heads.

  Optionally, a gas exhaust suction opening 125 may be provided between the nozzle heads 105 in the nozzle box 100 (see FIG. 1).

  FIG. 4 shows another example of the nozzle box 100 as shown in the first aspect of the present invention. The nozzle box 100 is provided so as to blow a high-temperature gas into a convection drying region of a facility for continuous drying of a paper sheet conveyed by air flow, for example, for continuous drying of a coated paper sheet conveyed by air flow, and continuous drying. It is provided to be installed across the width of the facility. The nozzle box 100 includes a plurality of nozzle units 105 on the nozzle box. In the example, the nozzle unit 106 is a nozzle head 106 that is removably mounted on the nozzle box 100 by bolts 107 and nuts. It is also possible for the nozzle unit to be formed integrally with the material of the nozzle box. In this example, although not necessarily essential to the present invention, all the nozzle heads of the nozzle box have the same nozzle configuration. The nozzle heads 106 are provided in a staggered manner on the nozzle box. As a result, when installed in the drying device, the nozzle units are provided in a staggered manner across the width of the drying device. However, other arrangements of nozzle units or nozzle heads in the nozzle box are possible, for example, the nozzle units or nozzle heads can be linearly aligned on the nozzle box, for example, as a result in the drying device. When installed, the nozzle unit is provided in linear alignment over the width of the drying device. The nozzle head 106 includes a direct impingement nozzle 108 that ejects a jet of hot gas perpendicular to the average plane of the paper sheet to be dried. Each nozzle head 106 includes twelve inclined injection nozzles 114 provided to eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried. In the nozzle box head 106, although not essential to the present invention, the direct collision nozzle 108 is provided at the center of the nozzle head 106. The inclined injection nozzle 114 directly surrounds the collision nozzle 108. The inclined injection nozzles 114 are provided so that the jets of the inclined injection nozzles 114 are present on a plane distributed at equal intervals in the circumferential direction perpendicular to the nozzle box 100 when the inclined injection nozzles 114 are operated. Each of the twelve inclined injection nozzles 114 has a vector representing the injection direction of each inclined injection nozzle in use, and each of the twelve inclined injection nozzles 114 has a different direction in the three-dimensional space. A hot gas chamber is provided inside the nozzle head 106. The hot gas chamber is provided for supplying hot gas to be ejected by the collision nozzle and by the inclined injection nozzle to at least one direct collision nozzle and the plurality of inclined injection nozzles. The hot gas chamber in the nozzle box is arranged to provide hot gas to the air chamber of each of the multiple nozzle heads. Optionally, a suction opening for gas discharge can be provided between the nozzle heads 106 in the nozzle box 100. Alternatively, the drying equipment can be fitted with a specific suction box aligned with one or more nozzle boxes.

  FIG. 5 shows still another example of the nozzle box 100 as shown in the first aspect of the present invention. The nozzle box 100 includes a nozzle unit 105 that is linearly aligned on the nozzle box, so that when installed in the dryer, the nozzle unit 105 is aligned linearly across the width of the dryer. Is provided. Optionally, the nozzle box is provided with a suction unit 125 between the nozzle units.

  FIG. 6 shows a cross-sectional view 600 in the paper transport direction, and FIG. 7 shows a plurality of nozzles as shown in the first aspect of the present invention (eg, as shown in the example of FIG. 1 or FIG. 4). A cross-sectional view 700 of an example of equipment for continuous airflow drying of paper sheets (eg, coated paper sheets) comprising boxes 670, 770 is shown. The nozzle box 670 extends over the width available in the facility for transporting the paper sheets 650, 750. The nozzle box 770 is attached to the support structure 772 in the short direction. In this example, the first set of nozzle boxes as shown in the first aspect of the present invention is provided above a plane that can be used for transporting a paper sheet, and the first set according to the first aspect of the present invention. The two sets of nozzle boxes are provided below a plane that can be used for conveying paper sheets. The coated paper sheet 650 passes through the facility in the direction indicated by the arrow 660. Although not required, the facility includes an array of infrared emitters 680, eg, premixed gas fired infrared emitters, between nozzle boxes 670. The paper sheets 650 and 750 are conveyed by airflow in the facility without the edges of the paper sheets being held by mechanical means. The paper sheets 650 and 750 undulate in the conveyance direction of the paper sheet passing through the drying facility. The paper sheets 650 and 750 undulate in a direction perpendicular to the conveyance direction of the paper sheet passing through the drying facility.

FIG. 8 shows a vector representing the jet flow of the inclined injection nozzle of one nozzle box of the nozzle boxes of the equipment of FIGS. 6 and 7. An arrow 860 indicates the conveyance direction of the paper sheet passing through the drying facility. Vector V ₁ was, represents the sum of a vector of the inclined injection nozzle of the nozzle box having a jet component in the conveying direction of the paper sheet through the equipment. Vector V ₂ represents the vector sum of the inclination injection nozzle of the same nozzle box having a jet component in the opposite direction to the transporting direction of the paper sheet through the equipment. The vector V _S is the sum of the vector V ₁ and the vector V ₂ and has a component in the direction opposite to the direction in which the paper sheet passes through the drying facility.

  FIG. 9 shows another example of a nozzle box 900 according to the first aspect of the present invention. The nozzle box 900 is provided so as to blow a high-temperature gas into the convection drying region of the equipment for continuous drying of the paper sheet that is conveyed by airflow, and the moving direction of the paper sheet relative to the nozzle box 900 is indicated by an arrow 960. The nozzle box 900 includes a plurality of nozzle units 905 on the nozzle box. The nozzle unit 905 is a nozzle head 905 that is detachably mounted on the nozzle box 900 by bolts 907 and nuts. The nozzle heads 905 are provided in a staggered manner on the nozzle box. As a result, when installed in the drying device, the nozzle units are provided in a staggered manner across the width of the drying device. Each nozzle head 905 includes two direct impingement nozzles 908 that eject hot gas perpendicular to the average plane of the paper sheet to be dried. The nozzle head 905 includes inclined injection nozzles 909, 911, and 912 that are provided so as to eject a jet of high-temperature gas at an inclination angle with respect to the average plane of the paper sheet to be dried. The inclined injection nozzle 909 is provided so as to eject a hot gas jet in a direction crossing the moving direction of the paper sheet. Vectors 995 and 997 indicate the jet direction of the jet flow from the inclined jet nozzle 909. The four inclined spray nozzles 911 are provided so as to eject a jet in the direction indicated by the arrow 991, which is the direction opposite to the paper moving direction. The two inclined spray nozzles 912 blow out in directions indicated by arrows 993 and 994, which form an acute angle with respect to the moving direction of the paper sheet, respectively. The two inclined spray nozzles 912 blow out in directions away from each other. It is shown that the provision of the inclined jet nozzle 912 in which the jet forms an acute angle with respect to the moving direction of the paper sheet and the two inclined jet nozzles 912 blow away from each other leads to an improved drying efficiency of the paper sheet. Yes.

  The inclined injection nozzle 912 is provided in the casting nozzle head 905 by drilling an oblique hole. All of the inclined spray nozzles in nozzle heat 905 are provided in the casting nozzle head by drilling holes of the same diameter. All of the inclined injection nozzles 909, 911, and 912 are supplied with hot gas from a hot gas chamber inside the nozzle heat 905. Therefore, the mass of the hot gas ejected per unit time is the same for each of the inclined spray nozzles 909, 911 and 912. As a result, the mass of the hot gas ejected per unit time in the direction opposite to the movement of the paper sheet is larger than the mass of the hot gas ejected per unit time in the direction of movement of the paper sheet. Such an arrangement has been shown to provide a more efficient drying facility.

  FIG. 10 shows an embodiment 1000 of equipment for continuous airflow drying of paper sheets according to the second aspect of the present invention. The facility 1000 includes a number of nozzle boxes 1070 and 1071 as shown in the first aspect of the present invention. Two successive nozzle boxes 1070, 1071 compare the position of the nozzle unit in the first nozzle box of two consecutive nozzle boxes with the position of the nozzle unit in the second nozzle box of two consecutive nozzle boxes. And nozzle units 1006 arranged in a staggered manner. A series of infrared emitters 1080, preferably gas fired infrared emitters, are positioned between two successive nozzle boxes 1070, 1071. A suction opening 1090 is provided between the nozzle box and the series of infrared emitters for gas discharge.

  FIG. 11 shows another example of the nozzle box as shown in the first aspect of the present invention. The nozzle box 1100 is provided so as to blow high-temperature gas into the convection drying region of the equipment for continuous drying of the paper sheet conveyed by airflow, and the moving direction of the paper sheet relative to the nozzle box 1100 is indicated by an arrow 1160. The nozzle box 1100 includes a plurality of nozzle units 1105 on the nozzle box. The nozzle unit 1105 is a nozzle head 1105 that is detachably mounted on the nozzle box 1100. The nozzle head 1105 does not have sharp corners to prevent the risk of damaging the paper if an unexpected contact between the paper to be dried and the nozzle head occurs. The nozzle heads 1105 are provided in a staggered manner on the nozzle box. As a result, when installed in the drying device, the nozzle units are provided in a staggered manner across the width of the drying device. Each of the nozzle heads comprises four direct impingement nozzles 1108 that each eject a jet of hot gas perpendicular to the average plane of the paper sheet to be dried. The direct impingement nozzle has several lines in the direction of the nozzle box that coincide with the width direction of the paper sheet to be dried, traversing only one direct impingement nozzle of the nozzle head, while the width direction of the paper sheet to be dried The other line in the direction of the nozzle box that crosses the two direct impingement nozzles of the same nozzle head, and the other line in the direction of the nozzle box that matches the width direction of the paper sheet to be dried is the same nozzle head. It is provided so as not to cross the direct impact nozzle. Such an arrangement of direct impingement nozzles has proven to provide better uniformity of heat transfer to the paper sheet to be dried by the direct impingement nozzle. Each of the nozzle heads includes four inclined spray nozzle arrays, and each of the inclined spray nozzle arrays includes a large number of inclined spray nozzles provided in a straight line. The two inclined spray nozzle rows 1110 are each aligned on a line in the direction of the nozzle box that coincides with the width direction of the paper to be dried, and one of the two inclined spray nozzle rows is the paper to be dried. It is provided so as to blow out in the moving direction of the sheet, and the other row is provided so as to blow out in the direction opposite to the moving direction of the paper sheet to be dried. The nozzle head additionally comprises two inclined spray nozzle rows 1111, 1112 that are each aligned on a line that forms an angle of, for example, 60 ° with the direction of the nozzle box that coincides with the width direction of the paper to be dried. . Each of the nozzles (direct impingement nozzle and inclined spray nozzle) is provided in the nozzle head as a perforated circular opening perpendicular to the surface of the nozzle head perforated with a circular opening. The nozzle box is provided with a suction opening 1125 for discharging gas between the nozzle heads. The nozzle box arrangement of FIG. 11 shows particularly beneficial results in terms of drying efficiency of the coated paper sheet due to the specific arrangement of direct impingement nozzles and inclined jet nozzles.

  FIG. 12 shows a hot air drying 1200 installation according to the second aspect of the present invention. The hot air drying facility 1200 includes a housing 1201 and a plurality of nozzle boxes 1270 according to the first aspect of the present invention. Means are provided for hot gas suction through nozzle openings (e.g. between nozzle units or nozzle heads) and / or between nozzle boxes, e.g. circular suction openings or slit-like suction openings. . Means are provided for collecting the sucked gas into the pipe 1202. Preferably, a pipe 1204 is provided for exhausting a part of the sucked gas from the facility. Means are provided for supplying fresh air into the facility where freshly supplied air introduced via line 1216 is mixed with the inhaled gas. At least a part of the sucked-in gas together with freshly supplied air, for example by a fan 1218, to be blown onto the paper sheet to be dried by the direct impinging nozzle of the nozzle box and by the inclined jet nozzle. A pipe 1224 is provided for recirculation back to the box or to the plurality of nozzle boxes. Means 1220 are provided for heating the mixture of inhaled gas and freshly supplied air before supplying it to the nozzle box. Such means can be, for example, a heat exchanger or a gas burner. Such a gas burner can be provided such that the combustion gas of the gas burner is added to the mixture of the sucked-in gas and newly supplied air. Means for controlling the flow of gas in different pipes or pipes, not shown in FIG. 12, for example, dampers are provided in the pipes.

Claims (15)

A nozzle box that blows out high-temperature gas into the convection drying region of the facility for continuous drying of paper sheets that are conveyed by airflow,
At least one direct impingement nozzle ejecting a jet of hot gas perpendicular to the average plane of the paper sheet to be dried;
A plurality of inclined injection nozzles comprising the inclined injection nozzles provided to eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried;
A nozzle box provided with the at least two inclined injection nozzles, wherein the plane containing the vector representation of the injection direction of at least two inclined injection nozzles does not include the vector directly representing the injection direction of the impinging nozzle.   The nozzle box comprises at least three inclined spray nozzles, each of the at least three inclined spray nozzles having a vector representing a spray direction of each inclined spray nozzle in use, and the at least three inclined spray nozzles The nozzle box of claim 1, wherein each of the vectors has a different direction in a three-dimensional space.   The inclined injection nozzle comprises or consists of a first set of inclined injection nozzles and a second set of inclined injection nozzles, and the first set of inclined injection nozzles in the first direction. The second set of inclined spray nozzles is provided to blow out, and is provided to blow out in a second direction, and the first direction is perpendicular to the second direction. The nozzle box according to 1 or 2.   The nozzle box as described in any one of Claims 1-3 with which the said nozzle box is provided with the suction opening for gas discharge | emission. The nozzle box includes a plurality of nozzle units on the nozzle box, and each of the units includes:
At least one direct impingement nozzle ejecting a jet of hot gas perpendicular to the mean plane of the paper sheet to be dried;
A plurality of inclined injection nozzles comprising the inclined injection nozzles provided to eject a jet of hot gas at an inclination angle with respect to the average plane of the paper sheet to be dried;
The at least two inclined injection nozzles of the nozzle unit are provided in which the plane containing the vector representation of the injection direction of at least two inclined injection nozzles does not include the vector representing the injection direction of the direct impinging nozzle of the nozzle unit. The nozzle box as described in any one of Claims 1-4.   The nozzle box according to claim 5, wherein a suction opening for gas discharge is provided between the nozzle units in the nozzle box.   The nozzle box according to claim 5 or 6, wherein a nozzle unit is provided as a nozzle head attached to the nozzle box.   The nozzle according to any one of claims 5 to 7, wherein the at least one direct collision nozzle is provided in a central part of the nozzle unit, and the inclined injection nozzle surrounds the at least one direct collision nozzle. box.   A direction in which the first portion of the inclined nozzle is blown inward toward the at least one direct collision nozzle, and the second portion of the inclined nozzle is away from the at least one direct collision nozzle. The nozzle box according to claim 8, which is provided so as to blow out.   The inclined injection nozzles in the nozzle unit are provided so that the jets of the inclined injection nozzles are present on a plane distributed at equal intervals in the circumferential direction perpendicular to the nozzle box when the inclined injection nozzles are operated. The nozzle box according to any one of claims 5 to 9.   A continuous airflow conveying type drying of a paper sheet, comprising the nozzle box according to any one of claims 1 to 10, wherein the nozzle box extends over a width available in the facility for conveying the paper sheet. Equipment.   One or more nozzle boxes according to any one of claims 1 to 10, wherein the vector vector represents the injection direction and has the injection impact of the inclined injection nozzle of the nozzle box as an intensity. The facility according to claim 11, wherein a sum is provided to point in a direction opposite to the transport direction of the paper sheet through the drying facility.   The said equipment is provided with many nozzle boxes as described in any one of Claims 1-10, and at least 2 continuous nozzle boxes are nozzle units in the said 1st nozzle box of the said 2 continuous nozzle boxes. The equipment according to claim 11 or 12, comprising the nozzle units arranged in a staggered manner by comparing the positions of the nozzle units in the second nozzle box of the two consecutive nozzle boxes. A method for continuous drying of paper sheets,
Equipment for continuous drying is used as shown in any one of claims 11-13,
A paper sheet is conveyed through the facility to dry the paper sheet in the facility for continuous drying;
The paper sheet is air-flowed in the facility without the edge of the paper sheet being held by mechanical means,
The paper sheet undulates in the conveying direction of the paper sheet passing through the drying facility;
And the paper sheet undulates in the direction perpendicular to the transport direction of the paper sheet through the drying facility.   The vector sum of the vectors representing the ejection direction and having the ejection impact of the inclined ejection nozzle of the nozzle box as a magnitude refers to a direction opposite to the transport direction of the paper sheet passing through the drying facility. Item 15. The method according to Item 14.

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