CA1055290A - Machine and process for the production of paper - Google Patents
Machine and process for the production of paperInfo
- Publication number
- CA1055290A CA1055290A CA261,944A CA261944A CA1055290A CA 1055290 A CA1055290 A CA 1055290A CA 261944 A CA261944 A CA 261944A CA 1055290 A CA1055290 A CA 1055290A
- Authority
- CA
- Canada
- Prior art keywords
- suspension
- stock
- gas
- duct
- ducts
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
- D21F1/022—Means for injecting material into flow within the headbox
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
- D21F1/024—Details of the feed chamber
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
- D21F1/026—Details of the turbulence section
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
- D21F1/028—Details of the nozzle section
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F11/00—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines
- D21F11/002—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines by using a foamed suspension
Landscapes
- Paper (AREA)
Abstract
A MACHINE AND PROCESS FOR THE PRODUCTION OF PAPER
Abstract of the Disclosure Gas in the form of fine bubbles is passed into the stock suspension in a mixing zone within the turbulence zone of the breast box before the suspension is passed through the breast box outlet. This prevents the gas bubbles from separating out of the suspension. The gas ducts are arranged at the smallest cross-section or at the entrance to a step-like widening of a suspension duct in the breast box. The gas may be pumped in or drawn in under the suction force of the suspension flow.
Abstract of the Disclosure Gas in the form of fine bubbles is passed into the stock suspension in a mixing zone within the turbulence zone of the breast box before the suspension is passed through the breast box outlet. This prevents the gas bubbles from separating out of the suspension. The gas ducts are arranged at the smallest cross-section or at the entrance to a step-like widening of a suspension duct in the breast box. The gas may be pumped in or drawn in under the suction force of the suspension flow.
Description
lOSSZ90 This invention relates to a machine and process for the production of a material in web form, particularly paper, from a suspension of fibers in water.
As is known, various types of paper making machines 5. and processes have employed a breast box which receives a stock suspension via a feed line and which delivers the stock suspension onto a water permeable element in layered fashion.
Further, in some cases, as described in British Patent Spec-ifications 1,129,757 and 1,329,409, it has been known to 10. feed air or gas into the stock suspension to form a foam con-taining finely distributed air bubbles. On the one hand, this improves the quality of the resulting paper while, on the other hand, there is a considerable energy saving, since smaller quantities of water are circulated in the paper ma-15. chine. In order to form such foams, special mixing deviceshave been provided in the feed line at a relatively consider-able distance from the breast box. However, since there is a risk of the air bubbles separating out in the feed line and in the breast box, special stabilizers and emulsifiers have 20. to be added to the water used for forming the stock suspen-sion. These agents render the process expensive and are undesirable in the finished paper or web material. For this reason, these gas injecting processes have not been accepted on a widespread scale.
25. Accordingly, it is an object of the invention to provide a process and a machine by means of which it is possi-ble to form a water and gas mixture in a stock suspension without the use of stabilizers and emulsifiers.
It is another object of the invention to prevent 30. separation out of gas bubbles mixed into a stock suspension.
As is known, various types of paper making machines 5. and processes have employed a breast box which receives a stock suspension via a feed line and which delivers the stock suspension onto a water permeable element in layered fashion.
Further, in some cases, as described in British Patent Spec-ifications 1,129,757 and 1,329,409, it has been known to 10. feed air or gas into the stock suspension to form a foam con-taining finely distributed air bubbles. On the one hand, this improves the quality of the resulting paper while, on the other hand, there is a considerable energy saving, since smaller quantities of water are circulated in the paper ma-15. chine. In order to form such foams, special mixing deviceshave been provided in the feed line at a relatively consider-able distance from the breast box. However, since there is a risk of the air bubbles separating out in the feed line and in the breast box, special stabilizers and emulsifiers have 20. to be added to the water used for forming the stock suspen-sion. These agents render the process expensive and are undesirable in the finished paper or web material. For this reason, these gas injecting processes have not been accepted on a widespread scale.
25. Accordingly, it is an object of the invention to provide a process and a machine by means of which it is possi-ble to form a water and gas mixture in a stock suspension without the use of stabilizers and emulsifiers.
It is another object of the invention to prevent 30. separation out of gas bubbles mixed into a stock suspension.
2. ~,4 Briefly, the invention provides a machine and a process for the production of paper in which gas bubbles can be mixed into a stock suspension and maintained therein prior to formation of a paper web.
5. The machine comprises a feed line for delivering a flow of stock suspension from a suitable source, a water per-meable element for receiving the stock suspension in layered form, a breast box and a mixing means for forming fine gas bubbles in the stock suspension. The breast box is connected 10. to the feed line for receiving the stock suspension and for delivering the suspension onto the water permeable element.
The breast box also has a turbulence means for agitating the stock suspension. This turbulence means includes a plurality of parallel suspension ducts each of which has at least one 15. step-like widening. The mixing means ,~ncludes at least one gas duct which leads into each of the suspension ducts for supplying gas into the stock suspension in the suspension ducts.
The process includes the steps of generating a 20. stock suspension of fibers in water, passing the suspension into a turbulence zone within a breast box to agitate the suspension, adding gas in the form of fine bubbles to the suspension at a mixing station within the turbulence zone and then passing the gas-impregnated suspension through an 25. outlet of the breast box adjacent the mixing station to a water permeable element. The mixing in of the air bubbles near the outlet precludes separation of the gas bubbles from the suspension before reaching the outlet and ensures that the stock suspension leaves the breast box with the required content 30. of gas bubbles without any need to use stabilizers and emulsifiers.
It has been found that a turbulence means construc-ted in the above manner is particularly suitable for the pres-ent purpose because, one the one hand, intensive turbulence and uniform distribution of the gas in the form of small 5. bubbles in the stock liquid are ensured while, on the other hand, a uniform distribution of the fibers in the suspension flow is obtained.
Suspension ducts of the kind having step-like widen-ings are known per se, for example, from German Auslegeschrift 10. 1,220,247 and U.S. Patent 3,725,197. In both cases, these suspension ducts are intended for intensive turbulence and hence to render the stock flow in the breast box uniform and to give a uniform distribution of the fibers for paper pro-duction in the entire flow.
15. The gas duct may be connected to that section of the suspension duct which has the smallest cross-section.
This ensures a certain distribution of the gas in the stock liquid flow before the flow reaches the first step-like widening. In addition, the negative pressure formed by the 20. flow of stock liquid in the suspension duct can be used to supply the gas.
The gas duct may alternatively lead into the sus-pension duct at the entrance end of a step-like widening.
In some cases, it may be advantageous to introdu~ the gas 25. directly into the turbulent zone where mixing takes place.
Finally, it is possible to connect at least two gas ducts to the suspension duct which are situated diametric-ally opposite one another in one line. The air flows which are then directed in opposition to one another can improve 30. the mixing of the air with the stock liquid.
These and other objects and advantages of the in-vention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:
5. Fig. 1 illustrates a partial sectional view of a paper machine according to the invention showing a breast box and part of a water-permeable element taken on line I-I in Fig. 2;
Fig. 2 illustrates a plan view of Fig. l;
10. Fig~ 3 illustrates a control diagram of the paper machine with the parts shown in Figs. 1 and 2;
Fig. 4 illustrates a partial sectional view of a detail of Fig. 1 and showing another embodiment of the breast box with the mixing device; and 15. Fig. 5 illustrates a view taken on line V-V in Fig. 4.
Referring to Figs. 1 and 2, a breast box 1 of a paper machine not shown in detail is used to form a paper fleece on a water permeable element such as a machine wire 2 20, extending over a cylinder 3. The wire 3 may extend in known manner along various dewatering devices to a point where the web of paper formed from the fleece is lifted off and passed onto subsequent processing.
The breast box 1 is connected via a stock or feed 25. line 4 to a device for generating and storing a stock suspen-sion, which contains fibers finely and uniformly distributed in water. The stock suspension may in kno~n manner also con-tain other materials, e.g. fillers, dyes and so on.
The stock suspension flows from the stock line 4 30, in the breast box and is delivered to a vertical distributor duct 5 from which the suspension passes to individual stock suspension ducts 6 of a turbulence means 7. The stock ducts 6 contain a plurality of sections 8, 9, 10 between which there are step-like widenings 11, 12. The downstreammost 5. duct 10 terminates just before an outlet 13 of the breast box 1, the outlet width being adjustable by means of a slide 14.
A mixing means for forming fine gas bubbles in the stock suspension is connected to the breast box 1 and includes a common air conduit 16 and a plurality of air ducts 15. Each 10. air duct 15 leads from the common air conduit 16 and is con-nected to a respective upstream section 8 of the stock ducts 6 at a mixing station within the turbulence zone of the breast box 1.
During operation, the stock suspension is fed to the 15. distributor duct 5 via the stock ~ine 4 and~flows in uniformly distributed form therefrom through the stock ducts 6 to the outlet gap 13 of the breast box 1 and from the box 1 onto the wire 2. At the same time, air is fed via the air conduit 16 and is intensively mixed with the stock liquid in the duct 20. sections 8, 9 and 10 and is uniformly distributed in the form of fine bubbles. Mixing is effected by the intensive turbu-lence in the zone of the step-like widenings 11, 12. Inten-sive eddies form in the flow after each widening 11, 12 and remain in the flow even at some distance from the step in 25. question.
The conditions in the breast box 1 are so selected that the turbulence at step 12 remains substantially undiminished as far as the outlet 13, so that in this turbulence zone the air bubbles are prevented from separating out of the water of 30. the stock suspension.
6.
~OS5290 As will be clear particularly from Fig. 1, the out-let 13 is disposed at a distance A from the step-like widen-ing 12, this distance being less than ten times the vertical dimension D of the duct section 10. This condition approxi-5. mately defines the critical zone where the turbulence in theflow is maintained substantially unweakened.
Referring to Fig. 3, wherein like reference charac-ters indicate like parts as above, the stock suspension is drawn from a chest or tank 20 having an overflow 21 and is fed 10. by a pump 22 to the feed line 4. The feed line 4 contains a pressure controller 23 with a`throttle device 24 so that the flow of suspension can be controlled relative to the pressure in the line 4. The stock suspension passes from the line 4, as already stated, to the distributor duct 5 of the breast 15. box 1. From duct 5, a return line 5' (see also Fig. 2) leads back to the chest 20~
Referring to Fig. 3, air is fed to the air conduit 16 by a blower 25, the delivery line 26 of which contains a : pressure controller 27 with a throttle device 28 for con-20. trolling the air flows relative to the pressure in the line 26.
A control system as shown in Fig. 3, with which the stock suspension and the air can be fed to the turbulence means 7 with accurately maintained pressures, ensures that con-stant relative proportions are maintained for the air and stock 25. suspension mixture.
It should be particularly noted that in theprocess according to the invention and the corresponding machine, it is possible, in some cases, to dispense with the supply of wire water otherwise necessary in paper machines and its ad-30. dition to the stock suspension taken from the chest 20, since lOS5290 the stock suspension can be fed to the turbulence means 7with the same density as in the chest 20. The uniform distri-bution of the fibers in the stock liquid, which was hitherto obtained by adding large quantities of wire water, can be ob-5. tained in this case by the addition of air. As a result, theenergy consumption is greatly reduced while dewatering of the fleece on the.permeable element 2 is facilitated. Given suitable stock suspension densities, it is even possible to dispense with the wire otherwise required for fleece forming, 10. and to place the fleece directly on a felt, e.g. of a felt press. The machine, e.g. a paper machine, can be greatly simplified in this way.
Referring to Figs. 4 and 5, the breast box can be provided with a distribution duct 5 which is followed by 15. two superposed rows of stock ducts 6 provided with step-like widenings 11 and 12. In addition, a common air conduit 40 is provided from which air ducts 41 lead to the individual ~ck ducts 6. Connecting ducts 42 branch from the air ducts 41 ar,d each discharges in the region of the step-like windings 11.
20. The ducts 42 are so constructed that each two are situated in one line and lead into the stock duct 6 at diametrically oppo-site places.
Of course, the machine illustrated can be modified in various ways. For example, a blower for feeding air to the 25. conduit 16 (Fig. 3) may be omitted since the suction effect of the flow of s*ock suspension may be sufficient to draw in the required air. Also, the turbulence means 7 may have a different number of steps and sections than the three sections 8, 9 and 10 shown. Further, more stock ducts 6 than those 30.shown may be superposed. A different number of air ducts may be provided to feed air to the stock ducts and, in some cases, an annular duct may be provided which surrounds a suitable sec-tion of the associated stock duct 6.
To satisfy the basic principle of the invention, 5. all that is required is a turbulence means which may be dis-posed in the breast box just before the outlet.
As already stated, the wire 2 shown in Fig. 1 may be replaced by another water permeable element, e.g. a felt.
The machine may be a double wire machine in which a fiber 10. fleece is placed between two wires or permeable elements running together.
Finally, in the arrangement shown in Fig. 3, wire water may be added in known manner to the]ine 5 upstream or downstream of pump 22 for the purpose of diluting the stock 15. fed from the chest 20.
The throttle device 24 provided to control the stock supply need not be disposed- in the stock line 4 as shown, but may be provided in a bypass conduit extending parallel to the pump 22. Finally, the pump 22 may be pro-20. vided with a speed control, by means of which the stocksupply to the breast box 1 can be controlled.
25.
30.
9.
5. The machine comprises a feed line for delivering a flow of stock suspension from a suitable source, a water per-meable element for receiving the stock suspension in layered form, a breast box and a mixing means for forming fine gas bubbles in the stock suspension. The breast box is connected 10. to the feed line for receiving the stock suspension and for delivering the suspension onto the water permeable element.
The breast box also has a turbulence means for agitating the stock suspension. This turbulence means includes a plurality of parallel suspension ducts each of which has at least one 15. step-like widening. The mixing means ,~ncludes at least one gas duct which leads into each of the suspension ducts for supplying gas into the stock suspension in the suspension ducts.
The process includes the steps of generating a 20. stock suspension of fibers in water, passing the suspension into a turbulence zone within a breast box to agitate the suspension, adding gas in the form of fine bubbles to the suspension at a mixing station within the turbulence zone and then passing the gas-impregnated suspension through an 25. outlet of the breast box adjacent the mixing station to a water permeable element. The mixing in of the air bubbles near the outlet precludes separation of the gas bubbles from the suspension before reaching the outlet and ensures that the stock suspension leaves the breast box with the required content 30. of gas bubbles without any need to use stabilizers and emulsifiers.
It has been found that a turbulence means construc-ted in the above manner is particularly suitable for the pres-ent purpose because, one the one hand, intensive turbulence and uniform distribution of the gas in the form of small 5. bubbles in the stock liquid are ensured while, on the other hand, a uniform distribution of the fibers in the suspension flow is obtained.
Suspension ducts of the kind having step-like widen-ings are known per se, for example, from German Auslegeschrift 10. 1,220,247 and U.S. Patent 3,725,197. In both cases, these suspension ducts are intended for intensive turbulence and hence to render the stock flow in the breast box uniform and to give a uniform distribution of the fibers for paper pro-duction in the entire flow.
15. The gas duct may be connected to that section of the suspension duct which has the smallest cross-section.
This ensures a certain distribution of the gas in the stock liquid flow before the flow reaches the first step-like widening. In addition, the negative pressure formed by the 20. flow of stock liquid in the suspension duct can be used to supply the gas.
The gas duct may alternatively lead into the sus-pension duct at the entrance end of a step-like widening.
In some cases, it may be advantageous to introdu~ the gas 25. directly into the turbulent zone where mixing takes place.
Finally, it is possible to connect at least two gas ducts to the suspension duct which are situated diametric-ally opposite one another in one line. The air flows which are then directed in opposition to one another can improve 30. the mixing of the air with the stock liquid.
These and other objects and advantages of the in-vention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:
5. Fig. 1 illustrates a partial sectional view of a paper machine according to the invention showing a breast box and part of a water-permeable element taken on line I-I in Fig. 2;
Fig. 2 illustrates a plan view of Fig. l;
10. Fig~ 3 illustrates a control diagram of the paper machine with the parts shown in Figs. 1 and 2;
Fig. 4 illustrates a partial sectional view of a detail of Fig. 1 and showing another embodiment of the breast box with the mixing device; and 15. Fig. 5 illustrates a view taken on line V-V in Fig. 4.
Referring to Figs. 1 and 2, a breast box 1 of a paper machine not shown in detail is used to form a paper fleece on a water permeable element such as a machine wire 2 20, extending over a cylinder 3. The wire 3 may extend in known manner along various dewatering devices to a point where the web of paper formed from the fleece is lifted off and passed onto subsequent processing.
The breast box 1 is connected via a stock or feed 25. line 4 to a device for generating and storing a stock suspen-sion, which contains fibers finely and uniformly distributed in water. The stock suspension may in kno~n manner also con-tain other materials, e.g. fillers, dyes and so on.
The stock suspension flows from the stock line 4 30, in the breast box and is delivered to a vertical distributor duct 5 from which the suspension passes to individual stock suspension ducts 6 of a turbulence means 7. The stock ducts 6 contain a plurality of sections 8, 9, 10 between which there are step-like widenings 11, 12. The downstreammost 5. duct 10 terminates just before an outlet 13 of the breast box 1, the outlet width being adjustable by means of a slide 14.
A mixing means for forming fine gas bubbles in the stock suspension is connected to the breast box 1 and includes a common air conduit 16 and a plurality of air ducts 15. Each 10. air duct 15 leads from the common air conduit 16 and is con-nected to a respective upstream section 8 of the stock ducts 6 at a mixing station within the turbulence zone of the breast box 1.
During operation, the stock suspension is fed to the 15. distributor duct 5 via the stock ~ine 4 and~flows in uniformly distributed form therefrom through the stock ducts 6 to the outlet gap 13 of the breast box 1 and from the box 1 onto the wire 2. At the same time, air is fed via the air conduit 16 and is intensively mixed with the stock liquid in the duct 20. sections 8, 9 and 10 and is uniformly distributed in the form of fine bubbles. Mixing is effected by the intensive turbu-lence in the zone of the step-like widenings 11, 12. Inten-sive eddies form in the flow after each widening 11, 12 and remain in the flow even at some distance from the step in 25. question.
The conditions in the breast box 1 are so selected that the turbulence at step 12 remains substantially undiminished as far as the outlet 13, so that in this turbulence zone the air bubbles are prevented from separating out of the water of 30. the stock suspension.
6.
~OS5290 As will be clear particularly from Fig. 1, the out-let 13 is disposed at a distance A from the step-like widen-ing 12, this distance being less than ten times the vertical dimension D of the duct section 10. This condition approxi-5. mately defines the critical zone where the turbulence in theflow is maintained substantially unweakened.
Referring to Fig. 3, wherein like reference charac-ters indicate like parts as above, the stock suspension is drawn from a chest or tank 20 having an overflow 21 and is fed 10. by a pump 22 to the feed line 4. The feed line 4 contains a pressure controller 23 with a`throttle device 24 so that the flow of suspension can be controlled relative to the pressure in the line 4. The stock suspension passes from the line 4, as already stated, to the distributor duct 5 of the breast 15. box 1. From duct 5, a return line 5' (see also Fig. 2) leads back to the chest 20~
Referring to Fig. 3, air is fed to the air conduit 16 by a blower 25, the delivery line 26 of which contains a : pressure controller 27 with a throttle device 28 for con-20. trolling the air flows relative to the pressure in the line 26.
A control system as shown in Fig. 3, with which the stock suspension and the air can be fed to the turbulence means 7 with accurately maintained pressures, ensures that con-stant relative proportions are maintained for the air and stock 25. suspension mixture.
It should be particularly noted that in theprocess according to the invention and the corresponding machine, it is possible, in some cases, to dispense with the supply of wire water otherwise necessary in paper machines and its ad-30. dition to the stock suspension taken from the chest 20, since lOS5290 the stock suspension can be fed to the turbulence means 7with the same density as in the chest 20. The uniform distri-bution of the fibers in the stock liquid, which was hitherto obtained by adding large quantities of wire water, can be ob-5. tained in this case by the addition of air. As a result, theenergy consumption is greatly reduced while dewatering of the fleece on the.permeable element 2 is facilitated. Given suitable stock suspension densities, it is even possible to dispense with the wire otherwise required for fleece forming, 10. and to place the fleece directly on a felt, e.g. of a felt press. The machine, e.g. a paper machine, can be greatly simplified in this way.
Referring to Figs. 4 and 5, the breast box can be provided with a distribution duct 5 which is followed by 15. two superposed rows of stock ducts 6 provided with step-like widenings 11 and 12. In addition, a common air conduit 40 is provided from which air ducts 41 lead to the individual ~ck ducts 6. Connecting ducts 42 branch from the air ducts 41 ar,d each discharges in the region of the step-like windings 11.
20. The ducts 42 are so constructed that each two are situated in one line and lead into the stock duct 6 at diametrically oppo-site places.
Of course, the machine illustrated can be modified in various ways. For example, a blower for feeding air to the 25. conduit 16 (Fig. 3) may be omitted since the suction effect of the flow of s*ock suspension may be sufficient to draw in the required air. Also, the turbulence means 7 may have a different number of steps and sections than the three sections 8, 9 and 10 shown. Further, more stock ducts 6 than those 30.shown may be superposed. A different number of air ducts may be provided to feed air to the stock ducts and, in some cases, an annular duct may be provided which surrounds a suitable sec-tion of the associated stock duct 6.
To satisfy the basic principle of the invention, 5. all that is required is a turbulence means which may be dis-posed in the breast box just before the outlet.
As already stated, the wire 2 shown in Fig. 1 may be replaced by another water permeable element, e.g. a felt.
The machine may be a double wire machine in which a fiber 10. fleece is placed between two wires or permeable elements running together.
Finally, in the arrangement shown in Fig. 3, wire water may be added in known manner to the]ine 5 upstream or downstream of pump 22 for the purpose of diluting the stock 15. fed from the chest 20.
The throttle device 24 provided to control the stock supply need not be disposed- in the stock line 4 as shown, but may be provided in a bypass conduit extending parallel to the pump 22. Finally, the pump 22 may be pro-20. vided with a speed control, by means of which the stocksupply to the breast box 1 can be controlled.
25.
30.
9.
Claims (6)
1. A machine for the production of paper comprising a feed line for delivering a flow of a stock sus-pension;
a water permeable element for receiving the stock suspension in layered form;
a breast box connected to said feed line for re-ceiving the stock suspension and for delivering the stock sus-pension onto said water permeable element, said breast box having a turbulence means therein for agitating the stock sus-pension, said turbulence means including a plurality of para-llel suspension ducts, each said duct having at least one step-like widening; and a mixing means for forming fine gas bubbles in the stock suspension, said mixing means including at least one gas duct leading into each of said parallel suspension ducts for supplying gas into the stock suspension in said suspension ducts.
a water permeable element for receiving the stock suspension in layered form;
a breast box connected to said feed line for re-ceiving the stock suspension and for delivering the stock sus-pension onto said water permeable element, said breast box having a turbulence means therein for agitating the stock sus-pension, said turbulence means including a plurality of para-llel suspension ducts, each said duct having at least one step-like widening; and a mixing means for forming fine gas bubbles in the stock suspension, said mixing means including at least one gas duct leading into each of said parallel suspension ducts for supplying gas into the stock suspension in said suspension ducts.
2. A machine as set forth in claim 1 wherein each gas duct is connected to a respective suspension duct at the smallest cross-section of said suspension duct.
3. A machine as set forth in claim 2 wherein a pair of said gas ducts are connected to a respective suspension duct in opposition to each other.
4. A machine as set forth in claim 1 wherein each gas duct is connected to a respective suspension duct at the en-trance end of a step-like widening.
5. A machine as set forth in claim 4 wherein a pair of said gas ducts are connected to a respective suspension duct in opposition to each other.
6. A process for the production of paper comprising the steps of generating a stock suspension of fibers in water;
passing the stock suspension into a turbulence zone within a breast box to agitate the suspension;
adding gas in the form of fine bubbles to the suspension at a mixing station within said turbulence zone; and then passing the gas-impregnated suspension through an outlet of the breast box adjacent the mixing station to a water permeable element whereby the gas bubbles in the sus-pension are prevented from separating out of the suspension be-fore reaching the breast box outlet.
passing the stock suspension into a turbulence zone within a breast box to agitate the suspension;
adding gas in the form of fine bubbles to the suspension at a mixing station within said turbulence zone; and then passing the gas-impregnated suspension through an outlet of the breast box adjacent the mixing station to a water permeable element whereby the gas bubbles in the sus-pension are prevented from separating out of the suspension be-fore reaching the breast box outlet.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH1263675A CH598407A5 (en) | 1975-09-30 | 1975-09-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1055290A true CA1055290A (en) | 1979-05-29 |
Family
ID=4384953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA261,944A Expired CA1055290A (en) | 1975-09-30 | 1976-09-24 | Machine and process for the production of paper |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5242902A (en) |
| AT (1) | AT341877B (en) |
| CA (1) | CA1055290A (en) |
| CH (1) | CH598407A5 (en) |
| DE (1) | DE2548795C3 (en) |
| FI (1) | FI64203C (en) |
| FR (1) | FR2326539A1 (en) |
| GB (1) | GB1563891A (en) |
| SE (1) | SE420850B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108660842A (en) * | 2018-04-09 | 2018-10-16 | 华南理工大学 | A kind of dilution water adding set of head box |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH608532A5 (en) * | 1976-01-27 | 1979-01-15 | Escher Wyss Gmbh | |
| AT377026B (en) * | 1980-12-19 | 1985-01-25 | Escher Wyss Gmbh | FABRIC DRIVE FOR A PAPER MACHINE |
| DE3211906C1 (en) * | 1982-03-31 | 1988-12-01 | J.M. Voith Gmbh, 7920 Heidenheim | Flotation apparatus injector |
| DE3741603A1 (en) * | 1987-12-09 | 1989-06-22 | Voith Gmbh J M | FABRIC DRAIN FOR A PAPER MACHINE OR THE LIKE. |
| DE4320243C2 (en) * | 1993-06-18 | 1996-02-22 | Voith Sulzer Papiermasch Gmbh | Headbox for a paper machine |
| DE4408713A1 (en) * | 1994-03-15 | 1995-09-21 | Escher Wyss Gmbh | Method and device for guiding a material web |
| DE4409415C5 (en) * | 1994-03-18 | 2005-02-17 | Voith Sulzer Papiermaschinen Gmbh | Metering device for a headbox of a paper machine |
| CN103821023A (en) * | 2014-03-03 | 2014-05-28 | 广东石油化工学院 | Complementary headbox |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1941424C3 (en) * | 1969-08-14 | 1980-07-10 | Escher Wyss Gmbh, 7980 Ravensburg | Headbox for a paper machine |
| GB1431603A (en) * | 1973-11-26 | 1976-04-14 | Wiggins Teape Ltd | Forming non-woven fibrous material |
-
1975
- 1975-09-30 CH CH1263675A patent/CH598407A5/xx not_active IP Right Cessation
- 1975-10-02 AT AT753375A patent/AT341877B/en active
- 1975-10-31 DE DE2548795A patent/DE2548795C3/en not_active Expired
-
1976
- 1976-09-07 FI FI762568A patent/FI64203C/en not_active IP Right Cessation
- 1976-09-23 SE SE7610555A patent/SE420850B/en unknown
- 1976-09-24 CA CA261,944A patent/CA1055290A/en not_active Expired
- 1976-09-27 JP JP51115712A patent/JPS5242902A/en active Granted
- 1976-09-29 FR FR7629301A patent/FR2326539A1/en active Pending
- 1976-09-29 GB GB40428/76A patent/GB1563891A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108660842A (en) * | 2018-04-09 | 2018-10-16 | 华南理工大学 | A kind of dilution water adding set of head box |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2548795B2 (en) | 1980-05-29 |
| SE420850B (en) | 1981-11-02 |
| FI64203B (en) | 1983-06-30 |
| SE7610555L (en) | 1977-03-31 |
| AT341877B (en) | 1978-03-10 |
| FR2326539A1 (en) | 1977-04-29 |
| DE2548795C3 (en) | 1981-01-29 |
| FI64203C (en) | 1983-10-10 |
| GB1563891A (en) | 1980-04-02 |
| CH598407A5 (en) | 1978-04-28 |
| DE2548795A1 (en) | 1977-03-31 |
| JPS5532840B2 (en) | 1980-08-27 |
| JPS5242902A (en) | 1977-04-04 |
| FI762568A (en) | 1977-03-31 |
| ATA753375A (en) | 1977-06-15 |
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