Title:
Former and headbox for said former
Kind Code:
A1


Abstract:
A former for a machine for the production of a fibrous web, particularly a paper or cardboard web including a headbox equipped with at least one stock suspension feed, one turbulence block equipped with several channels and/or a tube generator equipped with several channels, and a headbox nozzle whose suspension jet strikes an exposed or open surface of a dewatering belt, specifically a wire. Turbulence generating elements are allocated to at least a section of the channels and/or the headbox nozzle, in order to create turbulent flows in the suspension substreams in the channels, or in the headbox nozzle. The side of the suspension stream facing away from the dewatering belt is covered at least partially by a wall. A danger of the suspension stream bursting open is reduced to a minimum. In addition, swirling motions of considerably higher intensity than occur on conventional Fourdrinier wire formers are now permissible.



Inventors:
Bubik, Alfred (Ravensburg, DE)
Henssler, Joachim (Ravensburg, DE)
Resch, Petra (Polten, AT)
Wassermann, Alexander (Ulm, DE)
Ruf, Wolfang (Herbrechtingen, DE)
Application Number:
10/466354
Publication Date:
03/10/2005
Filing Date:
01/17/2002
Assignee:
BUBIK ALFRED
HENSSLER JOACHIM
RESCH PETRA
WASSERMANN ALEXANDER
RUF WOLFANG
Primary Class:
International Classes:
D21F1/02; D21F1/04; D21F9/00; (IPC1-7): D21F11/00; D21H11/00
View Patent Images:
Related US Applications:



Primary Examiner:
HALPERN, MARK
Attorney, Agent or Firm:
Todd T Taylor (Avilla, IN, US)
Claims:
1. -53. (Canceled)

54. A former for a machine for the production of a fibrous web, comprising: a headbox having: at least one stock suspension feed; at least one turbulence block connected to said at least one stock suspension feed, at least one said turbulence block having at least one of a plurality of channels and a tube generator having said plurality of channels, said plurality of channels having a plurality of suspension sub-streams running in said channels, said plurality of channels having at least one section; a headbox nozzle connected to at least one said turbulence block, said headbox nozzle producing a suspension stream; and turbulence generating elements allocated to at least one of said at least one section of said channels and said headbox nozzle, said turbulence generating elements creating a plurality of turbulent flows in one of said plurality of suspension sub-streams and said headbox nozzle; a dewatering belt having an open surface, said suspension stream incident on said open surface; and a wall at least partially covering a side of said suspension stream facing away from said dewatering belt.

55. The former of claim 54, wherein said former is a suction former.

56. The former of claim 54, wherein said dewatering belt is a wire.

57. The former of claim 54, wherein said wall is a stationary wall.

58. The former of claim 57, wherein said stationary wall is installed on said headbox.

59. 59.The former of claim 58, wherein said stationary wall is adjustably installed on said headbox.

60. The former of claim 54, wherein said wall is in motion.

61. The former of claim 54, wherein said wall is permeable to water.

62. The former of claim 54, wherein said wall is impermeable to water.

63. The former of claim 54, wherein said wall is formed by a second dewatering belt.

64. The former of claim 63, wherein said second dewatering belt is a revolving wire.

65. The former of claim 54, wherein said wall includes a coverage area, said coverage area includes an at least partially curved progression.

66. The former of claim 54, wherein said wall includes a coverage area, said coverage area includes an at least partially straight progression.

67. The former of claim 54, wherein said wall includes both an upper wall with an upper wall length and a lower wall with a lower wall length, said lower wall length is not greater than 90% of said upper wall length.

68. The former of claim 67, wherein said lower wall length is not greater than 60% of said upper wall length.

69. The former of claim 67, wherein said lower wall length is not greater than 30% of said upper wall length.

70. The former of claim 54, wherein at least one said section of said channels includes at least one turbulence causing insert.

71. A former for a machine for the production of a fibrous web, comprising: a headbox having: at least one stock suspension feed; at least one turbulence block connected to said at least one stock suspension feed, at least one said turbulence block having at least one of a plurality of channels and a tube generator having said plurality of channels, said plurality of channels having a plurality of suspension sub-streams running in said channels, said plurality of channels having at least one section; a headbox nozzle connected to at least one said turbulence block; and turbulence generating elements allocated to at least one said section of said channels, said turbulence generating elements creating a plurality of turbulent flows in said plurality of suspension sub-streams, each said turbulent flow rotating in a similar direction in said plurality of suspension sub-streams.

72. The former of claim 71, wherein said former is one of a suction former and a twin wire former.

73. The former of claim 71, further including helix spirals installed in at least one said section of said channels for a production of said turbulent flows that rotate in said similar direction.

74. The former of claim 71, wherein said headbox includes a tube generator with nozzles for a feeding of a stock suspension into a respective said channel, each said channel has a corresponding center plane progressing in a longitudinal direction through said channel, said feeding occurs asymmetrically relative to each said center plane.

75. The former of claim 74, wherein each said channel has a respective channel wall, in each said channel said feeding occurs approximately tangentially to said respective channel wall.

76. The former of claim 74, further including a plurality of jets in fluid communication with said stock suspension and corresponding said channels, said stock suspension being fed through each said jet to said corresponding channel on only one side of said corresponding center plane.

77. The former of claim 76, wherein said stock suspension is fed through each said jet to said corresponding channel on the same side of said corresponding center plane for each said channel.

78. The former of claim 71, wherein said headbox includes at least one inlet for a supply of at least one of dilution water, air and chemicals.

79. The former of claim 78, wherein said supply of at least one of dilution water, air and chemicals occurs essentially in an axial direction of a respective channel.

80. The former of claim 71, further including both a forming roll having a second radius of curvature and a wall being located in an area opposite said forming roll, said wall being both at least partially curved and having a first radius of curvature, said first radius of curvature equal to or greater than said second radius of curvature.

81. The former of claim 80, wherein said wall is stationary.

82. The former of claim 80, wherein said wall covers a circumferential length of said forming roll, said circumferential length approximately between 100 to 400 mm.

83. The former of claim 81, wherein said wall is one of rigid, deflection resistant and flexible.

84. The former of claim 80, wherein said wall is both movable and is formed by an additional dewatering belt, said wall covers a circumferential length of said forming roll, said circumferential length approximately between 100 to 1500 mm, said circumferential length approximately between 100 to 400 mm corresponds with a circumferential angle of said forming roll approximately between 25° to 120°.

85. The former of claim 84, wherein said additional dewatering belt is a revolving wire.

86. The former of claim 84, wherein said dewatering belt is routed around a breast roll prior to said circumferential length when viewed in a direction of belt travel, said breast roll has a third radius of curvature, said first radius of curvature in an area covering said forming roll is greater than said third radius of curvature.

87. The former of claim 71, further including at least one lamellar plate sectioning said headbox nozzle.

88. The former of claim 87, wherein said headbox nozzle includes at least one nozzle wall, at least one of said at least one lamellar plate and said at least one nozzle wall has a whirl producing contour.

89. The former of claim 88, wherein said whirl producing contour is a washboard countour.

90. The former of claim 88, wherein at least one of said at least one lamellar plate and said at least one nozzle wall include contours which generate turbulence.

91. The former of claim 90, wherein at least one of said at least one lamellar plate and said at least one nozzle wall include at least one interference body.

92. The former of claim 91, wherein said at least one interference body of said at least one nozzle wall is a discontinuous tapering of a cross section of said at least one nozzle wall.

93. The former of claim 87, wherein said headbox nozzle has a headbox nozzle length, said at least one lamellar plate has a lamellar plate length not exceeding 70% of said headbox nozzle length.

94. The former of claim 71, wherein said headbox nozzle has a headbox nozzle length less than approximately 400 mm.

95. The former of claim 71, further including an outlet cross section of said channels being essentially round.

96. A headbox for a machine for the production of a fibrous web, comprising: at least one stock suspension feed; at least one turbulence block connected to said at least one stock suspension feed, at least one said turbulence block having at least one of a plurality of channels and a tube generator having said plurality of channels, said plurality of channels having a plurality of suspension sub-streams running in said channels, said plurality of channels having at least one section; a headbox nozzle connected to at least one said turbulence block; and turbulence generating elements allocated to at least one said section of said channels, said turbulence generating elements creating a plurality of same direction turbulent flows in said plurality of suspension sub-streams.

97. The headbox of claim 96, wherein said headbox is for a former.

98. The headbox of claim 96, further including both a stationary wall connected to said headbox nozzle and a suspension stream emerging from said headbox nozzle, said stationary wall covering said suspension stream.

99. The headbox of claim 98, wherein said stationary wall is adjustable.

100. The headbox of claim 98, wherein said stationary wall is permeable to water.

101. The former of claim 98, wherein said stationary wall is impermeable to water.

102. The former of claim 98, wherein said stationary wall includes both an upper wall with an upper wall length and a lower wall with a lower wall length, said lower wall length is not greater than 90% of said upper wall length.

103. The former of claim 102, wherein said lower wall length is not greater than 60% of said upper wall length.

104. The former of claim 102, wherein said lower wall length is not greater than 30% of said upper wall length.

105. The former of claim 96, wherein said at least one section of said channels includes at least one turbulence generating insert.

106. A headbox for a machine for the production of a fibrous web, comprising: at least one stock suspension feed; at least one turbulence block connected to said at least one stock suspension feed, at least one said turbulence block having at least one of a plurality of channels and a tube generator having said plurality of channels, said plurality of channels having a plurality of suspension sub-streams running in said channels, said plurality of channels having at least one section; a headbox nozzle connected to at least one said turbulence block; and turbulence generating elements allocated to at least one said section of said channels, said turbulence generating elements creating a plurality of turbulent flows in said plurality of suspension sub-streams, each said turbulent flow rotating in a similar direction in said plurality of suspension sub-streams.

107. The headbox of claim 106, wherein said headbox is for a former.

108. The headbox of claim 106, further including helix spirals installed in at least one said section of said channels for a production of said turbulent flows that rotate in said similar direction.

109. The headbox of claim 106, wherein said headbox includes a tube generator with nozzles for a feeding of a stock suspension into a respective said channel, each said channel has a corresponding center plane progressing in a longitudinal direction through said channel, said feeding occurs asymmetrically relative to each said center plane.

110. The headbox of claim 109, wherein each said channel has a respective channel wall, in each said channel said feeding occurs approximately tangentially to said respective channel wall.

111. The headbox of claim 109, further including a plurality of jets in fluid communication with said stock suspension and corresponding said channels, said stock suspension being fed through each said jet to said corresponding channel on only one side of said corresponding center plane.

112. The headbox of claim 111, wherein said stock suspension is fed through each said jet to said corresponding channel on a same side of said corresponding center plane for each said channel.

113. The headbox of claim 106, wherein said headbox includes at least one inlet for a supply of at least one of dilution water, air and chemicals.

114. The headbox of claim 113, wherein said supply of at least one of dilution water, air and chemicals occurs essentially in an axial direction of a respective channel.

115. The headbox of claim 106, further including at least one lamellar plate sectioning said headbox nozzle.

116. The headbox of claim 115, wherein said headbox nozzle includes at least one nozzle wall, at least one of said at least one lamellar plate and said at least one nozzle wall has a whirl producing contour.

117. The headbox of claim 116, wherein said whirl producing contour is a washboard countour.

118. The headbox of claim 116, wherein at least one of said at least one lamellar plate and said at least one nozzle wall include contours which generate turbulence.

119. The headbox of claim 118, wherein at least one of said at least one lamellar plate and said at least one nozzle wall include at least one interference body.

120. The headbox of claim 119, wherein said at least one interference body of said at least one nozzle wall is a discontinuous tapering of a cross section of said at least one nozzle wall.

121. The headbox of claim 115, wherein said headbox nozzle has a headbox nozzle length, said at least one lamellar plate has a lamellar plate length not exceeding 70% of said headbox nozzle length.

122. The headbox of claim 106, wherein said headbox nozzle has a headbox nozzle length less than approximately 400 mm.

123. The headbox of claim 106, further including an outlet cross section of said channels which is essentially round.

Description:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a machine a machine for the production of a fibrous web, and, more particularly, to a former and former headbox.

2. Description of the Related Art

With suction formers, a longitudinal orientation of the fibers occurs at an appropriate increase in the operating speed of the paper machine in question. This may limit the scope of application of such suction formers to low operational speeds.

A relatively strong transverse orientation of the fibers, as well as a low longitudinal/transverse ratio can be achieved (see for example U.S. Pat. No. 5,876,364) through transverse movements that are indicated through various swirl-producing bodies in the turbulence block. However, a consequence of these transverse motions is the inherent danger of the suspension stream that is delivered by the headbox of the respective former bursting open when encountering an open surface, for example on the Fourdrinier wire.

SUMMARY OF THE INVENTION

The present invention provides an improved former and former headbox whereby the cited problems are eliminated.

The present invention provides a former, particularly a suction former of a machine for the production of a fibrous web, particularly a paper or cardboard web comprising a headbox equipped with at least one stock suspension feed, one turbulence block equipped with several channels and/or a tube generator equipped with several channels, and a headbox nozzle whose suspension jet strikes an exposed or open surface of a dewatering belt, specifically a wire. Turbulence generating elements are allocated to at least a section of the channels and/or the headbox nozzle, in order to create turbulent flows in the suspension substreams in the channels, or in the headbox nozzle. The side of the suspension stream facing away from the dewatering belt is covered at least partially by a wall. Based on this configuration, the danger of the suspension stream bursting open is reduced to a minimum. In addition, swirling motions of considerably higher intensity than occur on conventional Fourdrinier wire formers are now permissible.

The wall can be stationary or in motion. A stationary wall can, for example, be allocated to the headbox on which it can be installed adjustably. The wall can in addition, be permeable to water or impermeable to water. A movable wall or a wall in motion can be in the embodiment of an additional dewatering belt, that can specifically be in the form of a revolving wire.

In the coverage area the wall can possess an at least partially curved progression and/or an at least partially straight progression. Moreover, in a practical embodiment the lower wall has a maximum length of 90%, preferably of 60%, especially of 30% of the length of the upper wall. In a preferred practical embodiment of the former in accordance with the present invention, at least some of the channels are equipped with the turbulence generating inserts. Such turbulence generating inserts can basically be provided in the channels of a respective turbulence block and/or in the channels of a respective tube generator.

In hitherto conventional suction formers or in twin wire formers eddies occur in pairs in opposite rotational directions, that can lead to stripes. These are known as the so-called “Taylor-Görtler-Eddies” in Central Europe. The stripes occur especially in curved dewatering surfaces.

The present invention provides an improved former, particularly a suction former or twin wire former for a machine for the production of a fibrous web, specifically a paper or cardboard web, in which the previously cited problems are eliminated.

In accordance with an additional aspect of the present invention a former, specifically a suction former or twin wire former of a machine for the production of a fibrous web, specifically a paper or cardboard web is provided or this purpose; comprising a headbox that is equipped with at least one stock suspension feed, one turbulence block equipped with several channels and/or a tube generator equipped with several channels and a headbox nozzle. Turbulence generating elements are allocated to at least a section of the channels in order to create turbulent flows that rotate in the same direction in the suspension substreams in the channels. Same directional turbulence movement suppresses the undesirable stripes.

In a functional practical embodiment of the present invention helix type spirals are installed in at least a section of the channels in order to create turbulent flows that rotate in the same direction. Such helix type spirals can, for example, be installed in the channels of a turbulence block and/or in the channels of tube generator. The creation of turbulences through the means of helix type spirals can for example occur as described in U.S. Pat. No. 5,876,464.

Alternatively, or in addition, turbulent flows that are rotating in the same direction can be created particularly by the fact that, in a headbox comprising a tube generator, the supply of stock suspension through nozzles into a respective tube channel occurs asymmetrically and preferably at least essentially tangentially to the tube wall, relative to a center plane progressing in longitudinal direction through the tube channel. Advantageously, the stock suspension is fed through nozzles only on one side of the center plane respectively. Preferably, suspension supplied to the relevant pipe channels is fed into the various pipe channels through nozzles always on the same side of the respective center planes.

In contrast to Fourdrinier wires, the previously discussed, deliberately produced turbulences are kept very small in the sheet formation zone in other types of formers, particularly in suction and twin wire formers, since the surface of the suspension is “covered”, resulting in improved sheet formation, even at an increased stock consistency. In addition the headbox can be equipped with at least one feed for dilution water, air, chemicals and/or similar substances. The supply of dilution water, air, chemicals and/or similar substances may essentially occur in axial direction of a respective channel.

In accordance with an advantageous embodiment of the present invention, the wall can be located in an area opposite the forming roll and can be at least partially curved according to a radius of curvature that is preferably larger than or equal to the radius of the forming roll. Basically however, a smaller radius is also feasible, at least in sections. The wall can for example be stationary. Thereby it would preferably cover the circumferential surface of the forming roll, that is in a range of approximately 100 to approximately 400 mm. The stationary wall can particularly be rigid, deflection resistant or not deflection resistant.

In accordance with an additional advantageous design of the present invention whereby the wall is again provided in an area opposite the forming roll and is curved, at least partially, according to a curvature radius that is preferably larger than or equal to the radius of the forming roll, the wall can be movable or in motion and can be formed by an additional dewatering belt, particularly a revolving wire. In this instance, the wall preferably covers a circumferential area of this forming roll that is in the range of approximately 100 mm to approximately 1500 mm and/or corresponds with a circumferential angle of the forming roll of approximately 25° to approximately 120°.

The additional dewatering belt that forms the wall can be routed around a breast roll, prior to the area covering the forming roll, when viewed in the direction of belt travel. The curvature radius of the wall in the area covering the forming roll is preferably larger than the radius of the breast roll, or respectively the corresponding curvature radius of the wall in the area of this breast roll.

The headbox nozzle can be sectioned by at least one lamellar plate. A configuration without lamellar plates is also feasible. In a functional advantageous design at least one lamellar plate and/or at least one nozzle wall exhibit contours, especially swirl-producing washboard contours.

Alternatively, or in addition, at least one lamellar plate and/or at least one nozzle wall can have contours that serve to generate turbulent motion. At least one lamellar plate and/or at least one nozzle wall can for example be equipped with at least one interference body. Preferably the at least one interference body of the at least one nozzle wall is in the form of preferably a discontinuous tapering of the cross section. This formation provides a fluidic ideal turbulence chamber. In addition, at least one lamellar plate has a length not exceeding 70% of the length of the headbox nozzle.

In order to attain a sufficient effect, the headbox nozzle should be as short as possible. The headbox nozzle should preferably be shorter than approximately 400 mm. It is also advantageous if the outlet cross section of the channels or pipes is at least essentially round, since a square outlet cross section would dampen the effect.

In accordance with the present invention a headox is furthermore disclosed especially for a former of the relevant type previously described. Such a headbox includes at least one stock suspension feed, one turbulence block equipped with several channels and/or a tube generator equipped with several channels and a headbox nozzle. Turbulence generating elements are allocated to at least a section of the channels in order to create turbulent flows that rotate in the same direction in the suspension sub-streams in the channels.

In accordance with an additional aspect of the present invention a headbox, particularly for a former of the type previously described is provided, including at least one stock suspension feed, one turbulence block equipped with several channels and/or a tube generator equipped with several channels and a headbox nozzle. Turbulence generating elements are allocated to at least a section of the channels in order to create turbulent flows, rotating in the same direction, in the suspension sub-streams in the channels.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a partially schematic side view of an embodiment of a suction former of the present invention whose headbox includes a turbulence block that is equipped with turbulence generating inserts, and that is equipped with a stationary preferably adjustable wall, that covers the suspension stream, at least partially, on one side;

FIGS. 2-2d are cross-sectional views of various designs of the turbulence generating inserts of the present invention, viewed in the direction of arrow V in FIG. 1;

FIG. 3 is a schematic cross-sectional view of a headbox equipped with tube generator, as viewed along line I-I in FIG. 4, whereby the feeding of the stock suspension through nozzles into a respective tube channel occurs asymmetric and at least essentially tangential to the tube wall;

FIG. 4 is a schematic longitudinal section of an embodiment of the headbox of the present invention;

FIG. 5 is a schematic longitudinal section of an embodiment of headbox of the present invention including a turbulence block or tube generator into whose channels, at least into sections, helix type spirals or helix are installed;

FIG. 6 is a schematic side view of an embodiment of a former of the present invention with a movable wall, or a wall in motion that is formed by an additional dewatering belt and is located in an area opposite the forming roll and that covers a certain circumferential length of this forming roll;

FIG. 7 is a schematic longitudinal sectional view of an embodiment of a headbox nozzle, of the present invention that is sectioned by at least one lamellar plate, whereby at least one lamellar plate is equipped with at least one interference body;

FIG. 8 is a schematic perspective view of an embodiment of a headbox nozzle of the present invention that is sectioned by at least one lamellar plate, whereby at least one lamellar plate has a washboard contour; and

FIG. 9 is a schematic side view of an embodiment of a headbox of the present invention sectioned by at least one lamellar plate, whereby the upper and lower nozzle wall respectively are contoured.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIG. 1, there is shown a schematic side view of a former 10, which in this example is a suction former of a machine for the production of a fibrous web that may specifically be a paper or cardboard web.

A headbox 12 that is allocated to this former 10 includes a stock suspension feed 14, at least one turbulence block 18 that is equipped with several channels 16 and a headbox nozzle 20 whose suspension stream 22 strikes an exposed, that is an open surface 24′ of dewatering belt 24, which in this example is a wire.

Turbulence generating elements 26, in this example turbulence generating inserts, are allocated to at least one section of channels 16, in order to create turbulent flows 28 in the suspension substreams that are guided through the channels (also see FIG. 2). These turbulent flows 28 are illustrated schematically in FIGS. 2-2d, which show front views of various designs of the turbulence generating inserts, in the direction of arrow V in FIG. 1.

The side of suspension stream 22 facing away from the dewatering belt 24 is covered at least partially by wall 30. In the present example wall 30 is stationary, installed preferably adjustably on headbox 12. As can be seen in FIG. 1, wall 30 can, for example, be connected via link 32 with headbox nozzle 20. Wall 30 that is mounted on headbox nozzle 20 in this manner can be adjusted through pivoting by adjustment elements 34. Headbox nozzle 20 can, for example, be sectioned by at least one lamellar plate 36.

As can be seen in FIG. 1, wall 30 is curved at least slightly in the area of coverage. Wall 30 can, for example, be located in an area opposite forming roll 38. In the present example wall 30 is curved in accordance with a radius of curvature R1, that is larger than the radius R2 of the forming roll 38.

Wall 30 can include an upper wall shown at 30 and lower wall 30′. Lower wall 30′ has a lower wall length not greater than 90%, preferably 60%, especially 30% of an upper wall length.

Stationary wall 30 can for example cover a circumferential length L of forming roll 38, that is in a range of approximately 100 to approximately 400 mm. In FIG. 1 the circumferential angle of forming roll 38 resulting from a respective circumferential length L is indicated as “α”. The stationary wall may be rigid, deflection resistant or not deflection resistant. Curvature radius R1 of wall 30 can, if necessary, be larger than or equal to radius R2 of forming roll 38. In certain instances a smaller curvature radius R1 is also feasible.

In the example illustrated in FIG. 1 an additional dewatering belt 40, especially a wire is provided that is brought together with dewatering belt 24 at a location A. Furthermore, at least one disturbance body 60 of at least one nozzle wall 30 is designed as preferably a discontinuous tapering of cross section 64 (shown as broken lines). The tapering of the cross section may however also occur continuously and/or randomly.

In the present example wall 30 is impermeable to water. As can be seen especially from the following design examples, this type of wall may basically also be water permeable, especially if a movable wall or a wall in motion is provided in the embodiment of a dewatering belt, such as especially a wire.

FIGS. 3 and 4 are schematic illustrations of headbox 12 including tube generator 42 that is equipped with several channels 16 whereby turbulence generating elements are allocated to at least a section of channels 16, in order to create turbulent flows 28 that rotate in the same directions in the suspension sub-streams in the relating channels 16. The turbulence generating elements in the present example include nozzles 44 through which the supply of stock suspension into a respective tube channel 16 occurs asymmetrically and at least essentially tangentially to tube wall 46. Supply of the stock suspension through the nozzles occurs asymmetrically, relative to center plane E progressing in longitudinal direction through tube channel 16. In the present example this is always only on one side of this center plane E. As can be seen in FIG. 3, feeding into the various tube channels 16 through the nozzles always occurs on the same side of the center plane E, for example the right side in FIG. 3, resulting in same directional rotation of the various turbulent flows 28.

As can be seen in FIGS. 3 and 4, in addition to stock suspension feed 14, headbox 12 can additionally be equipped with at least one inlet 48 for dilution water, air, chemicals and/or other substances. As seen in FIG. 4 the supply of dilution water, air, chemicals and/or similar substances can essentially occur in an axial direction of a respective channel. Again, headbox nozzle 20 can be provided with or without lamellar plates. A turbulence block 18 can also be provided alternatively or in addition to the tube generator 42.

As illustrated in particular in FIG. 4, an intermediate chamber 50 can be provided, for example, following tube generator 42 which is equipped with rotation channels 16. In the available design example the rotational flow is produced by the asymmetric or tangential inflow of suspension.

FIG. 5 is a schematic longitudinal sectional view of another design form of a headbox 12, including tube generator 42. A turbulence block can again be provided alternatively or in addition. In the present example helix-type spiral or helix 52 are installed in at least a section of channels 16 of tube generator 42, or in the turbulence block, for the purpose of producing turbulent flows rotating in the same direction. As can be seen in FIG. 5, headbox 12 also includes stock suspension feed 14, a headbox nozzle 20 and a stationary, preferably adjustable wall 30. Headbox nozzle 20 can be sectioned by at least one lamellar plate 36, or can also be configured withouth lamellar plates. Helix-type spirals 52 can be configured and installed specifically so that same-directionally rotating turbulent flows again occur. Moreover, a respective rotational flow initiated by a relating helix-type spiral 52 can be produced, for example, as described in U.S. Pat. No. 5,876,564. In the design form illustrated in FIG. 5 an acceleration segment a of the headbox is followed by a section b that shows helix-type spirals 52. This is followed by a section c, for example constant deceleration or acceleration, further followed by an additional acceleration section d. A deceleration occurs in a subsequent section e.

FIG. 6 is a schematic partial illustration of former 10 that is equipped with a movable wall 30, or a wall in motion, that is formed by an additional dewatering belt 54 and that is located in area opposite forming roll 38 and that covers a certain circumferential length L of forming roll 38. Former 10 also includes dewatering belt 24 that is routed around forming roll 38 and is formed particularly by a wire, and has headbox 12 whose suspension stream 22 is directed into the area between forming roll 38 and breast roll 56, around which dewatering belt 54 that forms wall 30 is routed prior to the area that covers forming roll 38, viewed in direction of belt travel 1. Dewatering belt 54 can also specifically be a wire. After forming roll 38, two dewatering belts 24, 54 are run over an additional forming element 58.

In an area opposite forming roll 38 movable wall 30 that is formed by dewatering belt 54 is curved, at least partially according to a curvature radius R1 that is preferably larger than or equal to radius R2 of forming roll 38. Movable wall 30 can, for example, cover a circumferential length L of the forming roll 38 that is in a range of approximately 100 to approximately 1500 mm and/or corresponds with a circumferential angle a of forming roll 38 of approximately 25° to approximately 120°. As can be seen in FIG. 6, the additional dewatering belt 54 that forms wall 30 can be routed around breast roll 56, prior to the area covering forming roll 38, when viewed in direction of travel 1. Curvature radius R1 of wall 30 in the area covering forming roll 38 is preferably larger than radius R3 of the breast roll, or respectively the corresponding curvature radius R3 of wall 30 in the area of this breast roll 56.

FIG. 7 is a schematic longitudinal sectional view of headbox nozzle 20 that is sectioned by at least one lamellar plate 36, whereby at least one lamellar plate 36 is equipped with at least one interference body 60 in order to provide a turbulence generating profile. Moreover, at least one lamellar plate 36 has a length not exceeding 70% of the length of the headbox nozzle 20. At least one lamellar plate 36 and/or at least one nozzle wall 20′, 20″ can have contours that serve to generate turbulent motion.

FIG. 8 is a schematic, perspective partial view of headbox nozzle 20 that is sectioned by at least one lamellar plate 36, whereby at least one lamellar plate 36 has a swirl-producing contour, in this example a washboard contour. At least one lamellar plate 36 and/or at least one nozzle wall 20′, 20″ can possess this type of swirl-producing contour, for example in the form of a washboard contour.

FIG. 9 is a schematic longitudinal view of headbox 20, that is sectioned by at least one lamellar plate 36, where the upper and lower nozzle wall 20′ or 20″ respectively are contoured so that turbulence generating edges 62 are created in the flow area.

In order to achieve an appropriate effect a respective headbox nozzle 20 should be as short as possible, whereby headbox nozzle 20 is preferably shorter than approximately 400 mm. The outlet cross section of channels 16 or pipes is preferably at least essentially round, since a square cross section would dampen the effect.

Other desired combinations of the various former variations, as well as of the various headbox variations are feasible.

While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.