FI129217B - Method and system for screening coating mix in a fiber web machine - Google Patents

Method and system for screening coating mix in a fiber web machine Download PDF

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Publication number
FI129217B
FI129217B FI20195521A FI20195521A FI129217B FI 129217 B FI129217 B FI 129217B FI 20195521 A FI20195521 A FI 20195521A FI 20195521 A FI20195521 A FI 20195521A FI 129217 B FI129217 B FI 129217B
Authority
FI
Finland
Prior art keywords
screening
coating mix
applicator
screened
fiber web
Prior art date
Application number
FI20195521A
Other languages
Finnish (fi)
Swedish (sv)
Other versions
FI20195521A1 (en
Inventor
Ilkka Naatti
Teemu Nieminen
Christian Prinz
Original Assignee
Valmet Technologies Oy
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Valmet Technologies Oy filed Critical Valmet Technologies Oy
Priority to FI20195521A priority Critical patent/FI129217B/en
Priority to DE102020114450.4A priority patent/DE102020114450A1/en
Priority to ATA50476/2020A priority patent/AT522849B1/en
Priority to CN202010498391.XA priority patent/CN112080961B/en
Publication of FI20195521A1 publication Critical patent/FI20195521A1/en
Application granted granted Critical
Publication of FI129217B publication Critical patent/FI129217B/en

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22—Addition to the formed paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22—Addition to the formed paper
    • D21H23/24—Addition to the formed paper during paper manufacture
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
    • B01D35/02—Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D37/00—Processes of filtration
    • B01D37/04—Controlling the filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C11/00—Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00
    • B05C11/10—Storage, supply or control of liquid or other fluent material; Recovery of excess liquid or other fluent material
    • 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
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22—Addition to the formed paper
    • D21H23/32—Addition to the formed paper by contacting paper with an excess of material, e.g. from a reservoir or in a manner necessitating removal of applied excess material from the paper

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Coating Apparatus (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Treatment Of Fiber Materials (AREA)

Abstract

The invention relates to a method for screening coating mix in a fiber web machine. In the method, coating mix is pumped from a machine tank (10) to an applicator (12) with a feed pump (15). Coating mix is screened before said applicator (12). The whole flow of coating mix from the machine tank (10) is screened more than once before said applicator (12). The invention also relates to a system for screening coating mix in a fiber web machine.

Description

METHOD AND SYSTEM FOR SCREENING COATING MIX IN A FIBER WEB
MACHINE The present invention relates to a method for screening coat- ing mix in a fiber web machine, in which method coating mix is pumped from a machine tank to an applicator, and coating mix is screened before said applicator. The invention also relates to a system for screening coating mix in a fiber web machine.
The known fiber web machines include different kinds of coat- ing stations like sizers and coaters. The coating station has a machine circulation where coating mix is screened and pumped to an applicator and the excess coating mix is re- turned from the coating station to a machine tank. The screening device removes foreign material from the coat- ing mix circulating in the machine circulation. Coating mix, like sizing agent such as starch or coating color is applied to the fiber web by means of the applicator. Foreign material is impurities and fibers coming into the circulating coating mix from the fiber web. Especially recycled pulp contains many impurities, like sand and ink. Coating mix is screened after pumping. Actually, the screen- N ing device is positioned near to the coating station while a N feed pump is right to the machine tank. Then screening influ- S ences to the flow of coating mix and the screening result is S weak. In practice, while the screening device gets clogged, E 30 the flow in the feed line decreases. Similarly, the coating = station must be stopped during the cleaning of the screening 2 device. Some machine circulations has an extra screening de- = vice, but they have limited screening capacity. At the same time, extra components result extra costs. EP0916765A1 dis- closes a method and an assembly according to the preambles of the independent claims 1 and 7 respectively.
The object of the invention is to provide a novel method for screening coating mix in a fiber web machine, the method be- ing more efficient and reliable than before without produc- tion breaks.
Another object is to provide a novel system for screening coating mix in a fiber web machine, the system be- ing more efficient than before but more simply and less ex- pensive to manufacture and use.
The characteristic features of the method according to the invention are stated in the accompanying Claim 1 and the system in Claim 7. The method and system are easy to implement into a fiber web machine.
The first time installation is simply, but the system can be also retrofitted with no problems.
By the method, the screen- ing result gets better, while common components can be uti- lized.
The invention is described below in detail by referring to the enclosed drawings, which illustrate some of the embodi- ments of the invention, in which
Figure 1 shows the system according to the invention, Figure 2 shows a variant of the system of Figure 1, Figure 3 shows another variant of the system of Figure 1, o Figure 4 shows a partial enlarging of the system according > 25 to the invention.
O Figure 5 shows still another variant of the system of Figure = 1. i In Figure 1, a system for screening coating mix in a fiber 3 30 web machine according to the invention is shown.
Here only 2 the main components of the system is included.
For coating N mix there is a machine tank 10, which is usually located at the basement of the fiber web machine, i.e. under the machine level 11. Here only one applicator 12 is shown.
There can be one or two applicators in one coating station.
For example, one applicator for each side of the fiber web.
With the ap- plicator, coating mix is applied on a fiber web.
In addition, the fiber web machine may have one or more coating station.
Each coating station has own machine circulation with a ma- chine tank.
The applicator is a part of a coating station like a curtain coating station, a blade coating station with roll application or a sizing section with film coating.
Other application methods in blade coating heads are jet applicator and short dwell applicator.
The excess coating mix is re- turned back to the machine tank 10 via return line 13. There might be a separate return tank where excess coating mix is first led and then pumped to the machine tank via return screening (not shown). The return screening is guite often vibrating screen or pressure screening without separate col-
lecting tank and pump.
The system also includes a screening equipment 14 for screen- ing coating mix.
In addition, there is a feed line 25 from the machine tank 10 to the applicator 12. Then there is a feed pump 15 arranged on the feed line 25 for pumping coating mix from the machine tank 10 to the applicator 12. In other words, coating mix is pumped from a machine tank 10 to an ap- o plicator 12 with a feed pump 15. As the machine tank 10, the > 25 feed pump is located at the basement near to the machine tank O 10. According to the invention, the screening eguipment 14 is + arranged to the feedline 25 as a bypass and the screening I equipment 14 has a flow factor bigger than 1 to screen the + whole flow of coating mix from the machine tank 10 before a 30 said applicator 12 more than once.
Accordingly in the method, 2 coating mix is screened before said applicator 12. In other N words, the whole flow of coating mix from the machine tank 10 is screened more than once before said applicator 12. Then coating mix is surely cleaned, advantageously already before the feed pump. In addition, the flow of coating mix from the feed pump to the applicator stays constant. The screening equipment 14 is arranged onto the feed line 25.
So all of the flow is screened. Coating mix is screened more than once, preferably before the feed pump 15. In this way, coating mix is surely cleaned and the bypass circulation is short. In practice, the screening equipment 14 has an inlet line 16 and an accept line 17 which are together with a part 18 of the feed line 25 formed as a circulation circuit 19 forming. This bypass circulation can then easily be fitted on the feed line 25 with basic components like T-joints. See the partial enlarging of the system according to the invention in Figure 4. By this way, the system is easy to install and also retrofit. Simultaneously the screening equipment can be easi- ly locate in vicinity the machine tank 10. Usually at the basement there is more space than near to the applicator. Al- so the circulation circuit is as short as possible.
In addition to the position of the screening equipment, the capacity of the screening eguipment is new and surprising. As mentioned earlier, coating mix is screened more than once be- fore the feed pump. In other words, the circulation circuit 19 has a flow capacity, which is bigger than flow capacity of = 25 the feed line 25. In this way, coating mix is screened con- > stantly and more than once. Actually coating mix is screened = several times before pumping to the applicator. According to > the invention, the flow capacity of the circulation circuit S 19 is 1,1 - 6, preferably 2 - 4 times the flow capacity of N 30 the feed line 25. Coating mix will constantly circuit and be 3 screened and the necessary flow 1s pumped to the applicator. N The excess coating mix is returned to the circulation circuit 19 via the part 18 of the feed line 25.
Figure 1 shows a basic system according to the invention. Here the screening equipment 14 includes a single screening device 20 located near to the machine tank 10. In other words, coating mix is screened with a single screening device 5 20. In addition, the circulation circuit 19 is equipped with a circulation pump 21. Then coating mix is forced to circu- late via the screening equipment and that way coating mix is screened several times before pumping to the applicator. If the screening device is clogged, coating mix will flow anyway to the applicator via the feed line. Figure 2 shows another embodiment where the screening eguip- ment 14 includes two parallel screening devices 20 and 207. Then coating mix is screened with two screening devices 20 and 207 arranged parallel. There can be more than two screen- ing devices arranged parallel. In this way, the screening ef- fect stays constant and the clogging of the screening devices is slower. And more, said parallel screening devices 20 and 20’ can be used alternately. Then, when one screening device in under cleaning, the other screening device is on duty. In this way coating may be continuous. The screening device to be cleaned is easy to bypass by closing the inlet valves 22 or 22’ and outlet valves 23 or 23’ correspondingly. Advanta- o geously the screening eguipment 14 includes one or more pres- > 25 sure screens, which have high capacity and are easy to clean.
S = In Figure 3, the system includes also a screening unit 24 ar- I ranged on the feed line 25 between the feed pump 15 and the = applicator 12. This situation may happen when the system ac- io 30 cording to the invention is retrofitted. The screening unit 2 24 already in use is remained, but the feed line 25 is N equipped with a screening equipment 14 preferably before the feed pump 15.
The feed pump 15, the screening devices 20 and 20’, the cir- culation pump 21 and the screening unit 24 has their own mo- tor, which are shown with a letter M.
In Figure 5, the screening equipment 14 is also at the base- ment near to the machine tank 10, but now arranged after the feed pump 15. In the system according to the invention coating mix is led from the screening device back to the feed line and coating mix is screened more than once.
When coating mix is screened before the feed pump, the flow stays constant and undisturbed from the feed pump to the applicator.
Then coating mix spread evenly on the fiber web.
Also the whole flow of coating mix is securely screened.
In Figures are shown only the feed line 25 and the return line 13 without valves and sensors.
Also, the ventilation and cleaning lines of the screening devices are not shown.
Thus, here the screen includes an inlet, an accept and a reject.
By the system, the best possible cleaning result is achieved for supply flow of the feed pump.
There is no need to modify o machine circulations, which keeps investments low.
In addi- > 25 tion, the machine circulation keeps running as previous with- O out changes to the valves or machine control.
By the method + and system, it is possible to have two passes or more through = the screening equipment before coating mix is used at the ap- = plicator.
Also, at the basement, there are room for screening io 30 equipment and the installation of the system is easier than 2 near to the applicator.
Actually, the system can be installed N even the fiber web machine is running.

Claims (15)

1. Method for screening coating mix in a fiber web ma- chine, in which method coating mix is pumped from a machine tank (10) to an applicator (12) with a feed pump (15), and coating mix is screened before said applicator (12), charac- terized in that the whole flow of coating mix from the ma- chine tank (10) is bypassed and screened more than once be- fore said applicator (12).
2. Method according to claim 1, characterized in that coating mix is screened before the feed pump (15).
3. Method according to claim 1 or 2, characterized in that coating mix is screened with a single screening device (20).
4. Method according to claim 1 or 2, characterized in that coating mix is screened with two or more screening de- vices (20, 207) arranged parallel.
5. Method according to claim 4, characterized in that said parallel screening devices (20, 20’) are used alternate- o ly. S 25 ro 6. Method according to any of claims 3 - 5, character- + ized in that the single screening device (20) or parallel = screening devices (20, 207) are located in vicinity the ma- = chine tank (10). © 30
O 5 7. System for screening coating mix in a fiber web ma- N chine, which system includes - a machine tank (10) for coating mix,
- an applicator (12) for applying coating mix on a fiber web, - a screening equipment (14) for screening coating mix, - a feed line (25) from the machine tank (10) to the app- licator (12), and - a feed pump (15) arranged on the feed line (25) for pumping coating mix form from the machine tank (10) to the applicator (12), characterized in that the screening eguipment (14) is ar- ranged to the feedline (25) as a bypass and the screening eguipment (14) has a flow factor bigger than 1 to screen the whole flow of coating mix from the machine tank (10) before said applicator (12) more than once.
8. System according to claim 7, characterized in that the screening eguipment (14) is arranged onto the feed line (25).
9. System according to claim 8, characterized in that the screening equipment (14) has an inlet line (16) and an accept line (17) which are together with a part (18) of the feed line (25) formed as a circulation circuit (19). O
10. System according to claim 9, characterized in that O 25 the circulation circuit (19) is eguipped with a circulation 3 pump (21). 3 =
11. System according to claim 9 or 10, characterized in = that the circulation circuit (19) has a flow capacity which io 30 is bigger than capacity of the feed line (25).
12. System according to claim 11, characterized in that the flow capacity is 1,1 - 6, preferably 2 - 4 times the flow capacity of the feed line (25).
13. System according to any of claims 7 - 12, character- ized in that the screening equipment (14) includes one or more pressure screens.
14. System according to any of claims 7 - 13, character- ized in that the system includes a screening unit (24) ar- ranged on the feed line (25) between the feed pump (15) and the applicator (12).
15. System according to any of claims 7 - 14, character- ized in that the screening eguipment (14) is arranged before the feed pump (15).
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FI20195521A 2019-06-14 2019-06-14 Method and system for screening coating mix in a fiber web machine FI129217B (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
FI20195521A FI129217B (en) 2019-06-14 2019-06-14 Method and system for screening coating mix in a fiber web machine
DE102020114450.4A DE102020114450A1 (en) 2019-06-14 2020-05-29 Method and system for screening a coating mixture in a fiber web machine
ATA50476/2020A AT522849B1 (en) 2019-06-14 2020-06-02 METHOD AND SYSTEM FOR SCREENING A COATING MIXTURE IN A FIBER WEB MACHINE
CN202010498391.XA CN112080961B (en) 2019-06-14 2020-06-04 Method and system for screening coating mixtures in a fibrous web machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FI20195521A FI129217B (en) 2019-06-14 2019-06-14 Method and system for screening coating mix in a fiber web machine

Publications (2)

Publication Number Publication Date
FI20195521A1 FI20195521A1 (en) 2020-12-15
FI129217B true FI129217B (en) 2021-09-30

Family

ID=73546971

Family Applications (1)

Application Number Title Priority Date Filing Date
FI20195521A FI129217B (en) 2019-06-14 2019-06-14 Method and system for screening coating mix in a fiber web machine

Country Status (4)

Country Link
CN (1) CN112080961B (en)
AT (1) AT522849B1 (en)
DE (1) DE102020114450A1 (en)
FI (1) FI129217B (en)

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5401899A (en) * 1993-04-15 1995-03-28 Westvaco Corporation Paper machine coating system
FI103290B (en) * 1997-11-13 1999-05-31 Valmet Raisio Oy Method and apparatus for separating contaminants from machine circulation in a coating station
FI117059B (en) * 2004-09-21 2006-05-31 Metso Paper Inc Method and apparatus for separating contaminants from machine circulation in a coating station
ES2318441T3 (en) * 2005-03-10 2009-05-01 Sappi Alfeld Gmbh PROCEDURE FOR THE CLEANING AND RECYCLING OF STUCK PAINTINGS.
CN202766905U (en) * 2012-08-30 2013-03-06 东莞理文造纸厂有限公司 Papermaking fine sieving system
CN204973245U (en) * 2015-08-11 2016-01-20 东莞玖龙纸业有限公司 Purify device of backward flow coating
CN205741768U (en) * 2016-06-29 2016-11-30 玖龙纸业（太仓）有限公司 A kind of coating processing system
CN207401239U (en) * 2017-10-31 2018-05-25 玖龙纸业（太仓）有限公司 A kind of coating cleaning system
CN208533261U (en) * 2017-12-12 2019-02-22 玖龙纸业（东莞）有限公司 A kind of pair of reflux coating is screened and purified device
CN207828686U (en) * 2018-01-23 2018-09-07 台山市邦泰鞋材有限公司 A kind of paper pulp separating screen device

Also Published As

Publication number Publication date
AT522849A3 (en) 2022-08-15
FI20195521A1 (en) 2020-12-15
AT522849A2 (en) 2021-02-15
DE102020114450A1 (en) 2020-12-17
AT522849B1 (en) 2022-11-15
CN112080961B (en) 2023-02-28
CN112080961A (en) 2020-12-15

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