Truong Thj Thu Huang Tgp chi KHOA HQC & CONG NGH$ 112(12)/2:69-72
NGHIEN Cinj ANH HlTdNG CUA CAU T^O DIA NGHIEN DEN C H A T LU*gfNG NGHIEN B Q T GIAY
Truo-ngThjThu Hinrng Trudng Dai hoc K^ thugt Cong nghi?p • DH Thdi Nguyen TOMTAT
DTa nghien Id chi tilt chinh ciia miy nghien. Tuy nhifin, vSn dl lya chpn kit cdu dTa nghiin phii hgp vdi mpt qui trinh nghiin cy thi vSn Id kh6 khan Idn cho ngdnh chl tao mdy trong nude. Bii viet trinh bdy sy dnh hudng ciia mOt si thong so c^u tgo dTa nghiin den chdt lugng bpt giay. Day Id CO sd cho vi§c thiet kl, che tao dTa nghien cho cdc co sd sdn xudt giay.
Tir khod: Nghiin. bpt gidy, dia nghiin, cdu l^o, chdl luting bdt gidy.
DAT VAN DE
Nghien bgt gidy Id mdt giai dogn quan trgng trong qud trinh sdn xudt gidy. Nghien quylt djnh tinh chat, ddc diem cdu tao ciia gidy.
Nghien lam cho xo sgi deo dai, mem mgi, dugc chdi hda, truong nd, lien kit vdi nhau bin chdc giup qud trinh tgo hinh td gidy dugc ddng deu va dan ket chat che. Trong qua trinh nghien, tinh nang ky thudt cua mdy, ddc diem cdu tao cua dTa nghiin Id yeu td quyet djnh chat lugng nghien [1,2,4,6],
CAC THONG SO CAU TAO DIA NGHIEN Be mat Idm viec cua dTa nghien dugc dac trung bdi so lugng, kich thudc cdc rang nghien, ranh nghien vd sy phdn bd ciia ranh tren be mat dTa [1,2,7].
Hinh I md td cdc thdng sd hinh hgc ca ban cua dTa nghien, gdm chieu rgng rang (a), chieu rgng ranh (b), chieu cao rdng (c), gdc qugt rang (6) va gdc nghieng rang (gdc nghiin) (a).
Hinh 1. Cdc thdng sd cua dia nghien
Tel-0902064199. Emad. huongk8@yahoc
ANH HudNG CUA THONG SO CAU TAO DIA NGHIEN DEN KET QUA NGHIEN Ky hieu s vd r idn lugt la chi so bieu thj dTa cd djnh va dTa quay. Dl thdy, so cdc dao nghien tren dTa nghien cd bdn kinh r dugc xdc dinh la:
. . 2;r.r n{r) = .cosa
a + b (1) Mat khde, theo [4], chieu ddi nghien phu thugc thdng sd thiet ke dTa va dugc xdc djnh:
L = j«^(r)./7^(r)6;£/7- (2) Trong dd:
+ L: Chieu ddi nghien;
+ n^r), n[(r): Sd lugng rang nghien tren dTa cd djnh vd dTa quay;
+ ri, T2: Bdn kinh ngodi vd ban kinh trong ciia dTa nghien.
Bieu thirc (I) vd (2) cho thdy, cdc thdng sd chieu rgng rang, rdng ranh, chieu cao rang, gdc nghieng rang deu quan he chat che tdi ket qud qua trinh nghien Chieu rpng rdng (a) la yeu td lien quan mat thiet vdi so lupng dao vd so lan cat qua giii'a hai rang nghien ddi dien.
Neu chieu rdng rdng nhd thi sd lugng rang vd sd lan cdt qua giu'a hai rang nghien ddi dien se tdng vd do dd se tang lugng xa sgi dugc nghien. Chieu rgng ranh nghien anh hudng den ddng bdt gidy chdy trong viing nghien.
Chieu rdng vd chieu sdu ciia ranh gidm se giiip cho xo sgi de dang dugc tiep xuc vdi
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Truang Thj Thu Huong Tgp chl KHOA HQC & C 6 N G N G H $ |2(12)/2: 69-72 mep rdng nghiin, thiic day qua trinh nghiin
nhung lam gidm kha ndng chira huyIn phii va toe dg ddng huyen phii bgt giay. Ngugc Igi, nlu chiiu sau rdnh Idn sg ldm cho ddng huyIn phii di qua may nghiin md khdng dugc nghiin. Gdc dao (a) anh hudng din so lugng rdng va chiiu dai rdng nghien cung nhu qud trinh vgn chuyen bgt giita cac dTa nghiin, Gdc nghieng rdng tdng sc Idm tdng chicu ddi nghien do dd sc tang cudng qud trinh nghien
\ a tdng lugng xo sgi dugc nghien.
Mdt khde, gid sir. xet Irudng hgp hai dao nghiin tiep xiic vol nhau khi dao roto trugt vd nen len dao stato nhu hinh 2.
Hinh 2. Tiep xiic giira hai rdng nghien Tgi vj tri tiep xiic, van tdc nghien v de thyc hien qud trinh nghien dugc phan tich thdnh hai thanh phdn Vi vd v„. Trong dd, v,, la van tdc theo phuang song song vdi dao cd djnh.
Ddy Id thanh phan chinh tao nen sy eg xdt vd nen so xgi, mdt phdn tao nen qud trinh cdt xo sai (ggi tat Id van tdc phan to sgi). Thdnh phan V, la van tdc theo phuang tilp tuyen chu yeu tao nen sy trugt ciia dao roto tren dao stato vd mdt phan lao nen qud trinh nen xa sgi trong qua trinh nghien (ggi tdt la van tdc cat sgi) [5],
Gia su, xet trudng hgp khi rang dTa nghiin quay cat qua rdng dTa nghien cd djnh khi chuyen ddng tir vi tri A den vi tri B trong khodng thdi gian tii' t den t +dt. OA la cung trdn bdn kinh p, OB Id cung trdn bdn kinh p+dp, vdi dp dugc xdc dinh bdi doan AC Doan AB va AD dugc xdc dmh bdi cdc gdc cpr vdcps(Hinh 3).
70
Hinh 3. Sii dich chuyin ciia rdng quay tren rdng cd djnh khi nghiin
Xet cac tam giac vudng ACB va ACD, bdng each biln doi lugng giac ta dl ddng xdc djah dugc van toe cdt sgi va phan to sgi khi nghi^
nhu sau:
yyfp
(op cosl a„ - arcsin
;(''"*0) (3).
Po sin a "I , , p J , |
' sin a „ . f^y, Trong dd: a^ la gdc giao nhau giira rdng dia quay vd dTa cd djnh.
Nhgn \et:
Tir hai bieu thirc (3) vd (4), cd the nhdn th^, dTa nghien quay vd dTa nghien cd dinh khong the bd tri cd phuong trimg khit len nhau.
Mat khac, trong giai doan nghien thu nhat can uu tien qud trinh cdt ngan xo sgi hon qua trinh phan to chdi hda, vi vay can tang giitn van tdc v, vd ngugc lai trong giai doan nghi&i thir hai can uu tien qud trinh phan ta chdi h6»
xo sgi hon qua trinh cat ngan xa sgi, vi vaj cdn tang gid trj van tdc v^.
Xet d giai doan nghiin thu hai, de tang v„ti can xem xet den thdnh phdn gdc nghieng rang nghien {^) vd gdc giao nhau giiJa rang (ft quay va rang dTa co dinh {^'^). B^ \„ tangta can giam sina va gidm sina,, (tuc gidm (k nhung vdi a^j^O, Mat khde, theo phuong trinh (3) tinh so cdc dao nghien L; i nhau tai mo!
diem dich chuyen dgc theo , co djnh trong khoang thdi gian bgt c troi ^ay nghiin ci
Truong Thi Thu Huong Tgp chi KHOA HOC & CONG NGHE ll2(12)/2:69-72 tren thi sd rang nghien tiep xiic nhau tdng khi
a nhd. Tuy nhien, khi a qua nhd thi Igi lam cho qud trinh dich chuyen cua ddng bgt trong dia nghien khd khan, va lam giam chiiu ddi ludi cdt do vay Idm giam ndng suat nghien [4]. Vi vgy, cdc thdng sd a,b,c vd gdc ^ c a n dugc lya chgn can than cho mgt qud trinh nghien cy thi. Bdi bao nay se tim hiiu dnh hudng ciia thdng so chieu rgng rdng (a) vd chieu rgng ranh (b) cua dTa nghien den qud trinh nghien bgt giay.
THUC NGHIEM
Mdy nghien thi nghipm la may nghiin dgng dTa gdm mgt dTa quay vd mgt dTa cd djnh.
Dudng kinh dTa 240mm. Tdc dg may nghien c6 the dieu chinh dugc tir 600 - 1500 v/ph).
Nguyen lieu nghien Id bdt gd thdng tay trang.
Ndng do hot nghien Id 3.5%.
Hinh 4. Mdy nghiin dia Cdc bg dTa nghien thi nghiem cd cdc thdng sd cdu tao nhu sau:
.Bang I. Cdc thdng sd cdu lao cua dia thi nghiem
Sit 1 2 , 3
4 5
Dirong k f n h D ( m i i i ) d.™.,
80 80 80 80 80
d-Bri.
240 240 240 240 240
a ( m m )
2.5 3 3,5
4 4,5
b ( m m )
4 4 4 4 4
c ( m m )
5 5 5 5 5
(")
a 10 10 10 10 10p
(")
24 24 24 24 24
^inh 5 minh hga mdt mau dTa nghien thi i(ighiem.
1K.ET QUA VA T H A O LUAN
So lugng va chieu ddi rdng nghien cijng nhu
^oc nghieng rdng nghiin xdc dinh hieu qua
•;at sgi va chdi hod sgi.
\nh hudng cua chieu rdng rdng nghien dugc
^ninhhpadhinhe.
Hinh 5 Bdn vedia nghiin
Chi^u dai Dghieo (L) \» cbieu r9oe rang (a)
Hinh 6. Anh huang cua chiiu rgng rang din chieu ddi nghien Anh hudng ciia chieu rdng rang nghien dugc minh hoa dhinh 7.
l i n - « | E o n ( K . e n ( : i
Linear iNJng luDni
Hinh 7. Moi quan hi giira chieu rdng rang vd do nghiin. lieu thu ndng lirgng khi nghien Tir hinh 7 ta thay, cac dTa co rdng cdng rgng, thi tieu thu nang lugng it nhung hieu qua nghien thap hon nhiTng dTa co rang hep. Dieu nay cd the dugc gidi thich nhu sau: Nghien bgt giay bang may nghien dTa, cdc lye hirdng kinh tren be mat dTa song song vdi nhau. Khi chieu rgng cdc rang nghien Idn thi so rang nghien tren be dTa nghien it. Khi do rat it sgi dugc tiep xuc vdi be mat rang. Hay ndi cdch
Truong Thj Thu Huong Tgp chi KHOA HQC & C 6 N G NGHE ll2(l2)/2:69-7a khac, it sgi nhgn dugc ndng lugng nghien tir
rdng nghiin va dugc nghien. Ngugc Igi, neu rdng nghiin hpp hon, so lugng rdng nghien tren bl m§t dTa nhieu hon, nhiiu sgi nhgn dugc ndng lugng nghien va dugc nghien nhieu hon do dd hipu qud nghien cao han. Do dd, khi muon tdng dg nghien vd hgn che vipc cdt ngdn sgi thi rdng nghiin nen cd kich thudc nhd hon,
KET LUAN
Vipc lya chgn kich thudc hinh hgc cua cdc thdng sd cau tao dTa nghiin Id rat quan trgng.
Cdc thdng so nay can dugc xdc djnh theo myc dich ciia tirng giai dogn nghiin. Chieu rgng rdng, chicu rgng ranh nghien nen nhd khi muon thyc hien qua trinh chdi hoa sgi va Idn hon khi mudn cdt ngdn sgi. Cac thdng so cau tgo nay se dugc nghien cuu ket hgp vdi khe hd dTa nghien, tdc do nghien de xdc djnh dugc logi dia nghien phii hgp vdi mgt qua trinh nghien cu the.
T A I LIEU THAM KHAO [1]. Jens Oiaf Heymer, Measurement of heterogeneity in low consistency pulp refining by comminution modeling.
[2]. Joseph M. Genco, Department of Chemicd Engineering.
[3]. Kristian Goldszer (2009), Papermakir^
Course Montevideo. Part II - Paper Processes.
[4], Hannu Paulapuro, Papermarking Part I, Slock Preparation and Wet End.
[5]. High consistency refining of mechanical pulps during varying refining conditions. Master of science thesis, Sweden, 2008
[6]. Lars Ake Hammar (2005), Literature survey Measurement techniques suitable for the refining zone of disc and conical LC refiners.
[7]. Matech Europe, fillings for disc refiners.
SUMMARY
STUDYING EFFECT OF SOME STRUCTURE PARAMETERS O F REFINER DISK ON REFINING PULP'S QUANLITY
Truong Thi Thu Huong College of Technology - TNU Refine disk is a main part of refiners. However, choicing a kind of refiner disk which filed a specific refining process is still a difficult problem for machine manufacture in Vietnam. This paper will present effect of some structure parameters of refine disc on pulp's quanlity. It is a basic to design, manufacture refine disc for pulp factories.
Key words: Refine, pulp, refiner disk, siructrure. quanlity pulp.
Plum bien khoa hgc: TS. Dd Thi Tdm - Tnrdng Dai hgc Ky thudt Cong nghiep - DH Thdi Nguyen
Tel- 0902064199: Emad lmongk8'.dyahoo c 11
