CN1243880C - Method and process arrangement in the short circulation of a paper machine - Google Patents
Method and process arrangement in the short circulation of a paper machine Download PDFInfo
- Publication number
- CN1243880C CN1243880C CNB028086716A CN02808671A CN1243880C CN 1243880 C CN1243880 C CN 1243880C CN B028086716 A CNB028086716 A CN B028086716A CN 02808671 A CN02808671 A CN 02808671A CN 1243880 C CN1243880 C CN 1243880C
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- China
- Prior art keywords
- pipeline
- fan pump
- flow box
- slurry
- flow
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- Expired - Fee Related
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- 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
- D21F1/66—Pulp catching, de-watering, or recovering; Re-use of pulp-water
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- Paper (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
A process arrangement in the short circulation of a paper machine comprises devices (10-13) for dilution of thick stock, centrifugal cleaners (14), and a headbox fan pump (16), as well as a pipe system connecting these. There is a direct flow connection from the centrifugal cleaners (14) along a pipeline (30) to the headbox fan pump (16), through which pipeline (30) a centrifugally cleaned stock flow (F6) is passed direct to the headbox fan pump (16) without any deaeration or dilution stages in between. A secondary line (32) is connected to the pipeline (30) for passing through it part of the centrifugally cleaned stock flow as a return flow (F7) back to the thick stock dilution devices (10-13). By this arrangement it can be ensured that the pressure on the suction side of the fan pump (16) remains substantially constant.
Description
Technical field
The present invention relates to the process unit of the short circulation of a kind of paper machine, it comprises equipment, centrifugal pulp cleaner, the fan pump of flow box and the pipeline system that connects these equipment that is used to dilute underflow.
The invention still further relates to the method for the short circulation of a kind of paper machine, this method is used to keep the constant pressure of inlet side (suction side) of the fan pump of flow box, wherein slurry is diluted to flow box concentration, and is purified by centrifugal pulp cleaner, is pumped into the wet end of paper machine then by flow box.
Background technology
In the short circulation of paper machine, slurry will pass through with the next stage before entering flow box: underflow is diluted to flow box concentration in one or two stage, and in centrifugal slagging-off, degasification and/or screening stage are removed different types of residue.The free degree of the paper-making process of considering the stability of whole paper-making process and being produced by disturbance, importantly the pressure of the inlet side of the fan pump of flow box can keep constant.If this pressure is non-constant, the flow that is produced by fan pump can change, thereby the pressure that causes the online slurry stream of flow box changes, and this point is reflected in the quantitative variation of paper web.
Deaerating tank generally is furnished with overflow pipe or fluid level controller (control), and its effect in deaerating tank is not only for the air in the system of removing, and is even in order to ensure the pressure of the inlet side of the fan pump of flow box.In addition, there is not deaerating tank on the Trunk Line of some device.For example, in the short circulation of paper machine or board machine, comprise centrifugal slagging-off during the stage, it is desirable to omit deaerating tank that described device generally comprises dual dilution system from the Trunk Line of slurry.In this respect, at first underflow being diluted to required concentration of centrifugal slagging-off stage, only is just slurry to be diluted to flow box concentration at last after centrifugal pulp cleaner.Underflow added in the machine water stream can finish above-mentioned dilution, the pressure of machine water stream is constant back pressure.The pressure of inlet side that can guarantee the fan pump of flow box in this way simultaneously keeps constant.Yet, when when producing the paper kind that needs high flow box concentration, for example supercalendered paper, featherweight coated paper and newsprint can not use dual dilution.
Summary of the invention
The objective of the invention is to solve the problem of constant pressure of the inlet side of the fan pump that how to keep flow box with a kind of new method.For realizing this purpose, adopt the dual dilution of slurry traditionally and deaerating tank is set on Trunk Line, and target of the present invention is in order to find a kind of substituting process unit.
The feature of process unit of the present invention characteristic as claimed in claim 1 is described.Similarly, the feature of method of the present invention characteristic as claimed in claim 6 is described.
In short circulation of the present invention, in the good slurry side of centrifugal slagging-off level, pipeline directly leads to without any degasification and/or dilution level between the fan pump of fan pump one degasification of flow box and/or good slurry side that the dilution level is usually located at centrifugal slagging-off level and flow box.Second pipeline is connected on this root pipeline between centrifugal pulp cleaner and the described fan pump, to carry back the diluent facilities of underflow as refluxing from the part slurry stream that centrifugal pulp cleaner is very starched side by second pipeline, thereby make described backflow concentrated area and be parallel to the inlet side that diluent stream enters mixing pump.Why selecting the backflow position like this is for fear of disturbance.The purpose of second pipeline is the variation for the mobile and pressure of the good slurry side that reduces centrifugal pulp cleaner.If want to improve the pressure of inlet side of the fan pump of flow box, a valve can be set on second pipeline.But this valve is not to want.
Process unit of the present invention is simple, and the number of groove and equipment will be less than traditional device.This device has also reduced the precipitation of calcium compound in flow box is surfed the Net pipeline system (approachpipe system) in the neutral technology, this result is due to the fact that partial CO 2 contained in the carbonate is released when the calcium carbonate as filler is transported in the deaerator.When air was removed from machine water, longer to the distance of online pipeline system, the filler that flows through deaerator still less.
Description of drawings
With reference to each width of cloth accompanying drawing the present invention is described below, but purpose not on the details that limits the invention to accompanying drawing.
Fig. 1 is the schematic diagram of the traditional short cyclic part of paper machine.
Fig. 2 is the schematic diagram of process unit of the present invention.
Fig. 3 is the modification of the process unit of Fig. 2.
The specific embodiment
Fig. 1 has briefly explained the short cyclic part of paper machine, especially traditional flow box connecting internet system (approach system).Fresh underflow material M is transported to the Mixed Zone 11 of wite pit 10, at this it is diluted to the required concentration of centrifugal slagging-off with plain boiled water, this concentration in the case with the concentration of waiting to be delivered to the slurry in the flow box much at one.Slurry stream F after the dilution
1To centrifugal pulp cleaner 14, in centrifugal pulp cleaner, from slurry, remove heavy seeds such as sand by mixing pump 12.Slurry stream F after the purification
2Be transported to deaerating tank 15, there is an air gap that is negative pressure the top of the Free Surface of slurry in the deaerating tank 15.Slurry stream F
3Be transported to the inlet side of flow box fan pump 16 by bottom, be transported to machine screen 18 then from deaerating tank 15.Slurry stream F
4Be transported to flow box 20 from the good slurry side (accept side) of machine screen 18, flow box 20 is fed to slurry the wet end of paper machine (not shown).Recovery is from the machine water F of wet end
10Be transported to wite pit 10, be used to dilute underflow M.
Liquid level in the deaerating tank 15 can keep constant by means of overflow pipe 15a, and by overflow pipe 15a, slurry is as backflow F
5Be transported to wite pit 10 and link to each other, be used to dilute underflow M.Wite pit 10 also comprises overflow pipe 10a.The wite pit 10 that has fluid level controller 10a keeps the constant pressure of the inlet side of mixing pump 12, and similarly, the deaerating tank 15 that has fluid level controller 15a keeps the constant pressure of the inlet side of fan pump 16.
Fig. 2 has provided the short circulation of paper machine of the present invention, and this weak point circulation has centrifugal slagging-off and single dilution, and does not comprise any deaerating tank on the Trunk Line.Underflow M is diluted in the bottom of wite pit 10, the slurry stream F after the dilution
1Mixed stock pump 12 is pumped into centrifugal pulp cleaner 14.The large quantities of good slurry that comes from the first order of centrifugal pulp cleaner 14 flows F as slurry
6Directly be delivered to flow box fan pump 16 along pipeline 30, fan pump 16 further is pumped to it machine screen 18.The good slurry stream F that comes from the first order of machine screen 18 afterwards
4Be transported to flow box 20, further be delivered to the wet end of paper machine then.
Second pipeline 32 device is in pipeline 30, and to fan pump 16, second pipeline part by good slurry is as backflow F from the good slurry side of centrifugal pulp cleaner 14 for pipeline 30
7Be transported to wite pit 10 and link to each other, be used to dilute underflow M.Because free bypass circuit, the pressure in the pipeline 30 of the inlet side of fan pump 16 keeps constant.Also can input flow rate in second pipeline 32 less than other process flow (not shown) of Trunk Line fluid.
The device of Fig. 3 is similar substantially to the device of Fig. 2, because the slurry after the dilution flows F in Fig. 3
1Be pumped to fan pump 16 through centrifugal pulp cleaner 14, fan pump 16 flows F with slurry
6Further be pumped into flow box 20 through machine screen 18, the part slurry after the centrifugal clarification is as backflow F
7Be transferred through second pipeline 32, be used for diluted slurry.This device is different from the device among Fig. 2, because underflow M is not in wite pit but diluted in the mixer 13 of a sealing that is called as the pipeline diluter.Underflow M, machine water F
10Backflow F with slurry after the centrifugal clarification
7Be transported to parallel flow (parallel flows) in the mixer 13 of inlet side of fan pump 12, like this backflow F of the slurry of the underflow of input stream M after diluted
7Surround machine water stream F
10Be positioned at outermost.Use the pipeline diluter further to reduce the required groove of short circulation and the flowing space.
Rely on the device shown in Fig. 2 and 3, can guarantee that the pressure of inlet side of fan pump 16 is even, thereby improve the stability of system and exempt and disturbing.Can be used for the common Pressure control of the fan pump 16 of mixing pump 12 and flow box simultaneously by device, promptly FEEDFORWARD CONTROL is come control operation speed, thereby improves the Pressure control of flow box 20.Wherein, two parts of technology are controlled simultaneously and along same direction, therefore can expect that situation will become better than in the past.
Process unit of the present invention is particularly suited for following paper machine and board machine: need centrifugal slagging-off but because high flow box concentration and can not use dual dilution and because technology and economic cause and do not need to use the slurry degasification.This method is applicable to that also multi-layer web is shaped, and the pulp suspension that wherein will form different pulp layers is processed separately before forming multi-layer web.
Process unit of the present invention is compared very simple with device well known in the prior art, because on its Trunk Line without any need for deaerating tank, also without any need for the dilution of dual slurry, and the pressure of the inlet side of these former fan pumps in order to ensure flow box evenly all is necessary.
Claims (6)
1. the process unit during a paper machine weak point circulates, comprise the equipment (10-13), centrifugal pulp cleaner (14), the fan pump (16) of flow box and the pipeline system that connects these equipment that are used to dilute underflow, wherein, there is a direct current to connect from the fan pump (16) of centrifugal pulp cleaner (14), the slurry stream (F after the centrifugal clarification along pipeline (30) to flow box
6) be delivered directly to the fan pump (16) of flow box through described pipeline (30), between the fan pump (16) of centrifugal pulp cleaner (14) and flow box without any degasification or dilution level, it is characterized in that, second pipeline (32) is connected on the described pipeline (30), and the slurry stream after the part centrifugal clarification is as (the F that refluxes
7) be transferred back underflow diluent facilities (10-13) by second pipeline (32), can guarantee that by this device the pressure on fan pump (16) inlet side keeps substantially constant.
2. process unit as claimed in claim 1 is characterized in that, described underflow diluent facilities comprises mixing pump (12), the inlet flow of underflow (M), machine water stream (F
10) and centrifugal clarification after the backflow (F of slurry
7) be transported to the Mixed Zone (11,13) that is positioned at the mixing pump inlet side.
3. process unit as claimed in claim 2 is characterized in that, described backflow (F
7) from the center and be parallel to machine water stream (F
10) and be transported to the inlet side of mixing pump (12).
4. as any described process unit in the above-mentioned claim, it is characterized in that for control operation speed, the fan pump (16) of described mixing pump (12) and flow box has common Pressure control, i.e. FEEDFORWARD CONTROL.
5. process unit as claimed in claim 1 is characterized in that, flow is connected to second pipeline (32) less than other process flow of the flow in the Trunk Line.
6. the method during the weak point of a paper machine circulates, be used to keep the constant pressure of inlet side of the fan pump of flow box, in the method, slurry is diluted to flow box concentration, and purified by centrifugal pulp cleaner (14), be pumped into the wet end of paper machine then by flow box (20), wherein, slurry stream (F
6) be delivered directly to the fan pump (16) of flow box from the good slurry side of centrifugal pulp cleaner (14), between the fan pump (16) of centrifugal pulp cleaner (14) and flow box without any degasification or dilution level, it is characterized in that the part slurry that comes from centrifugal pulp cleaner (14) by handle is as (the F that refluxes
7) carry back the diluent facilities of underflow, the pressure in the pipeline (30) from centrifugal pulp cleaner (14) to fan pump (16) keeps substantially constant.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20010830A FI111391B (en) | 2001-04-23 | 2001-04-23 | Process and process arrangement in the short circulation of a paper machine |
| FI20010830 | 2001-04-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1503865A CN1503865A (en) | 2004-06-09 |
| CN1243880C true CN1243880C (en) | 2006-03-01 |
Family
ID=8561032
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB028086716A Expired - Fee Related CN1243880C (en) | 2001-04-23 | 2002-04-12 | Method and process arrangement in the short circulation of a paper machine |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US20040144513A1 (en) |
| EP (1) | EP1399621B1 (en) |
| CN (1) | CN1243880C (en) |
| AT (1) | ATE338845T1 (en) |
| DE (1) | DE60214546T2 (en) |
| FI (1) | FI111391B (en) |
| WO (1) | WO2002086233A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI113971B (en) * | 2003-02-11 | 2004-07-15 | Metso Paper Inc | Stock treatment apparatus for treatment of stock passed to headbox of paper machine, comprises accept line of hydrocyclone plant and connected with stock line of stock fed from second stock chest |
| FI115234B (en) * | 2003-09-24 | 2005-03-31 | Metso Paper Inc | A process for making a laminated paper or board web |
| DE102004054236B4 (en) * | 2004-11-10 | 2007-06-06 | Voith Patent Gmbh | Method for mixing suspensions of different compositions |
| FI123392B (en) * | 2008-02-22 | 2013-03-28 | Upm Kymmene Oyj | Method for Precipitation of Calcium Carbonate in a Fibrous Web Process and Fiber Machine Machine Approach |
| DE102010038694A1 (en) * | 2010-07-30 | 2012-02-02 | Voith Patent Gmbh | constant part |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI103676B (en) * | 1998-06-10 | 1999-08-13 | Metso Paper Inc | Short-circuiting process arrangement for a paper or board machine |
| FI103677B (en) * | 1998-06-10 | 1999-08-13 | Valmet Corp | Procedure for regulating the surface and texture of a dosing container for a partial mass |
| US6200417B1 (en) * | 1998-06-29 | 2001-03-13 | Voith Sulzer Papiertechnik Patent Gmbh | Process and device for mixing stock suspensions |
-
2001
- 2001-04-23 FI FI20010830A patent/FI111391B/en active
-
2002
- 2002-04-12 EP EP02714251A patent/EP1399621B1/en not_active Expired - Lifetime
- 2002-04-12 WO PCT/FI2002/000311 patent/WO2002086233A1/en active IP Right Grant
- 2002-04-12 DE DE60214546T patent/DE60214546T2/en not_active Expired - Fee Related
- 2002-04-12 AT AT02714251T patent/ATE338845T1/en not_active IP Right Cessation
- 2002-04-12 CN CNB028086716A patent/CN1243880C/en not_active Expired - Fee Related
- 2002-04-12 US US10/475,504 patent/US20040144513A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| CN1503865A (en) | 2004-06-09 |
| FI111391B (en) | 2003-07-15 |
| DE60214546T2 (en) | 2007-08-30 |
| WO2002086233A1 (en) | 2002-10-31 |
| DE60214546D1 (en) | 2006-10-19 |
| ATE338845T1 (en) | 2006-09-15 |
| FI20010830A0 (en) | 2001-04-23 |
| EP1399621A1 (en) | 2004-03-24 |
| FI20010830A (en) | 2002-10-24 |
| US20040144513A1 (en) | 2004-07-29 |
| EP1399621B1 (en) | 2006-09-06 |
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| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
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| CF01 | Termination of patent right due to non-payment of annual fee |