KHOA HOC VACONG NGHE M d
NGHIEN CUU AP DUNG DONG CHAY BA PHA V A O P H U ' O N G P H A P B 0 M A I R L I F T DE VAN CHUYEN CHAT RAN N A M SAU DUKTI NUIDTC
TS. VU N A M NGAN Trudng Dai hgc Md-Dja chat
N
gUdi ta da ap dung nhieu phUdng phap khac nhau de van chuyen chat ran nhU: sir dung he thdng may bdm ly tam d cac md va cac nha may tuyen than, tuyen quang; he thdng van chuyen xi mang bang khi nen d cac nha may xi mang....Tuy nhien, phUdng phap bdm Airlift cung dang dUdc sir dung de khai thae va van chuyen khoang san d day bien, khai thae cat, sdi dudi nUdc, nao vet Idng moong d cac md...
PhUdng phap nay cho hieu qua cao va gia thanh re hdn so vdi cac phUdng phap khac. Dae diem ciia he thdng bdm Airiift la van chuyen ddng hdn hdp 3 pha: khi-ran-ldng.
Van de can dat ra la xac djnh ty le cac thanh phan trong hdn hgp nay phai hdp ly de cho phUdng phap dat hieu qua cao.
Bai bao nay gidi thieu phUdng phap tinh toan ty le chat khi (he sd cap khi) ciia ddng hdn hdp 3 pha sao eho phii hdp vdi lUdng hat ran eiing dUde van chuyen trong ddng hon hdp 3 pha.
Ngoai ra phUdng phap nay cung cho ta tinh dUdc dudng kinh tdi Uu ciia dng dan va hieu suat cao nhat ciia he thdng bdm Airlift.
1. Xac dinh luu lu'dng k h i h d p ly va hieu suat cua thiet bj b d m A i r l i f t
Viee tinh toan dUdc xuat phat tif sU can bang cdng suat ciia ddng chay d phan tren va dudi dng, ddng thdi ehii y tdi anh hudng ciia ma sat va tac dung trUdt giifa cac hat ran vdi chat Idng de xac djnh lUdng khi yeu d u eho viec bdm chat ran di len (hinh H.I).
De ddn gian trong qua trinh nghien ciru va tinh toan, cd the bd qua:
•:• Ton that ap suat do si/c can d mieng vao phia dudi va cho udn cong phan tren khi ddng chay ra khdi dng dan;
CONG NGHIEP MO SO 2 - 2 0 1 0
•:• Ddng nang eiia ddng ehay d mieng vao ong dan phia di/di;
•:• Phan ddng nang cua khi d cira ra tren ong dan;
<' Ton that do anh hudng trUdt va ma sat ciia rieng chat khi;
•:• Trong pham vi chieu cao h (hinh H.I), bd qua s U t h a m gia eiia chat khi.
Vi vay, ndng do the tich hat ran d tren dng (C^u) va dudi dng C^ o) la nhU nhau, nghia la:
Ch,U ~ Ch,C
(1)
Ky hieu chi s d " U " eho tren dng va chi sd "0"
cho dudi dng.
Khi xac djnh ty s d ap sua't p^/pg bd qua ma sat, theo [1] ta viet dUdc:
1
PnQH TEP, H (2)
Trong dd: p^, Pa - Gia tri ap suat eiia ddng hon hdp 3 pha trong budng trgn va ap suat khi quyen; p^ - Khdi lu'dng rieng eiia nUde; g - Gia td'c trgng trUdng;
H - Chieu sau doan dng ngap dUdi nUdc; Tg - Do ngap sau ciia budng tron (hinh H.I).
Tir hinh H . I , phUdng trinh can bang cdng suat ciia ddng hdn hdp d phia tren va di/dj dng la:
( N U + N T ) = N O (3)
Trong dd: N j , Ny va N Q - TUdng ifng la cdng suat d i n g nhiet, cdng suat d dudj dng va tren dng.
Cdng suat dudi dng du'dc tinh nhu sau [2]:
(Ph-Qh+Pn-Qn)
Pn g^E
APR,U
Pn ) Pn
(4)
Tai day, ma sat eiia phan di/dJ dng se la:
KHOA HOC VACONG NGHE MO
Pn
gH 1- TE H
8A„
TT^gD^^
Q .
R V
,Nm/kg. (5)
Ap gH
s,u Pn
Cdn ma sat trUdt d phan dudi dng dan se du'dc xac djnh bang bieu thirc sau day:
1 - i
H Pn T T D ^ C ^
4 Q h D R J
, Nm/kg. (6)
Cdng s u i t dang nhiet Nj, bang:
NT=P3.QKin^,W.
Pa
(7) Trong cac cdng thirc tren: Q^, 0^, - LUu lUdng ciia pha ran va pha nUde; p^ - Khdi lUdng rieng ciia hat ran; App y; Aps u - TUdng irng la ton that ap suat eiia ddng hon hdp d phan dudi dng va do sU trUdt; X„ - He sd ma sat ciia dng dan; Dp - Dudng kinh ciia
dng dan; C^ - Ndng do hat ran trong ddng hon hdp;
dh - Dudng kinh trung binh eiia hat ran; Cw- He sd sire can ciia hat; f - He s d hinh dang ciia hat; QK - Luu lUdng ciia chat khi tren dng dan.
Ne'u bd qua ton that ma sat d dng d i n khi nen tir may nen khi de'n ndi nap khi (budng hdn hdp - hinh 1), thi cdng sua't d phan dng dan phia tren NQ se dUdc tinh theo cdng thirc sau [2, 3]:
N„ = ( p , . Q , + p „ . Q j
P^ ' t b . O + g ( T E + h ) - Ap R.O Ap s.o PnW.
Cdn ma sat d phan dng dan nay se la:
AR,.(
gH H H
8A.
Pn - V H H^Ti^gD va ma sat trUdt bang:
' P t i _ - I ,Pn
, Nm/kg
(8)
(9)
^Ps,i
gH H > '
1 4 0 , 1
V D R ;
Nm/kg. (10)
Pn
1 fdn Tai eae cdng thirc tren: v,5o - Van tdc trung binh ciia ddng hdn hdp d phan tren dng; Appo; Apso - Ton that ap sua't ciia ddng hdn hdp d phan tren dng
PngH Pa
va do sU trUdt. Thay cac phUdng trinh tir (4) de'n (10) vao phUdng trinh (3) va bien ddi, ta se nhan dUde he sd ty le (he s d cap) khi la:
(11)
De cd the khao sat so sanh giOfa eae thiet bj Airiif khac nhau, can sir dung them ty s d v l do cao ciia he thdng dng dan, dUde bieu thj qua he sd a:
khac nhau. Hang s d Froude-Zahl ciia thiet bj Airiift dUdc viet:
Fr V ^ b a = - TE Tg/H
(TE + h) T^/H + h/H (12)
Day la mgt dai lUdng rat quan trgng (eung nhU he sd ddng dang) de so sanh cac thiet bi Airiift
g(TE+hy
Cdn hang s d Ole dUde bleu thj nhU sau:
Ap ^ PibgTg ^ gTg
, 2 •
EU:
PtbV tb PtbVfb
(13)
(14)
^
CONG NGHIEP MO SO 2 - 2 0 1 0
KHOA HOC VACONG NGHE MO
Tir day ta nhan dUdc tich s d eiia hai hang s d tren:
gTg v^b _ TE Eu.Fr
g(TE+h) (TE + h)
= a. (15)
%
1 - 01 + 1 ^ - 1 1 0 .
yPn
1-C,
PngH TE P, ' H 1 + PngH Te
D, ' H 1 + '
1 - a
r i - T g / H ')
^E a + 1 H
V J 8A, Ti'gD^
fQb]
Cho cdng suat hut ( N H ) de bdm dUdc chat ran, ta nhan dUde:
NH =PngH.fPt^-lJ.Qh +Phgh.Q„ W. (17)
Tir day ta tinh dUdc hieu sua't thiiy khi (r|) eiia thiet bj Airiift irng vdi trudng hdp hieu suat cua may nen k h i d che'dg d i n g nhiet (TITK). bang:
N,
ftfl,h
hij 1 - C h p
C, p,gH p , ^ H -1 il^ln PE
Po
-HLK- (18)
Tir cac phUdng trinh tren ta se tinh dUdc lu'dng khi yeu d u 0 ^ (tfnh tir he s d VK) va hieu sua't ri eiia thiet bi bdm Airiift
77771 3 -
n
M
1 ^
Bpt khi 5
Q h - ^ n ^ K
i + p 7
•PE
Hat ran
.^
1- ^Qh<Jn
HA. So do he thong thiet bi bam Airlift khai thae quang dudi nudc: 1 - Dudng ong din dudi; 2 - Budng trdn hon hgp; 3- Dudng ong din khi nen;
4 - May nen khi; 5 - Dudng ong din tren
3. Ap d u n g de t i n h toan cho he t h o n g t h i e t bj bdm Airlift
Ta cd the tha'y he s d a cd anh hudng rat cd ban den cac thdng s d ciia thiet bj Airiift trong viec nghien ciru m d hinh nhd gia trj a nay. Tir phuong trinh (11) sau khi bien ddi, ta nhan dUdc:
(16)
De bdm quang mang gan d day bien, sir dung he thdng thiet bi bdm Airiift (hinh H.I), ta cd eae so lieu n h u sau:
•:• LUU lUdng hat ran: Qh=0,0446 m^/s;
•:• C h i l u sau dudi mUe nudc bien: H=5000 m;
•:• Khdi lu'dng rieng ciia nudc: Pn=1000 kg/m^;
•:• Khdi lu'dng rieng ciia hat ran: Ph=2600 kg/m^;
• He s d ma sat ciia dng d i n : A.p=0,02;
• He s d hinh dang ciia hat ran: f = 1 ;
• He s d sire can eiia hat ran: C=0,4;
•:• Ndng do van tai hat ran: 0^=5 %;
•:• Ap suat khi quyen: Pa=98100 Pa;
^K
150.
100-
50-
0 7}.%
^ ° \ ?7ra.
-25 \ /
-15 \ / -10 y
& V.^
^
\ ^ /
\ V^^
A "°'^
' nil
1 1 1 1 ' 200 4 |600 800
DR.t-U DR.nnm
1 ^ 1
? H.2. Do thi xac dinh cac thong so lam viec hgp ly cua he thong bam Airlift (0^46000 m^/gid) Tren hinh H.2 la cac k i t qua tinh eho cac gia trj khac nhau ciia dudng kinh dng d i n DR, edn hieu suat dUde tinh theo phUdng trinh (18). Nd chi ra gia trj hieu sua't cue dai nhan dUdc d gia trj dudng kinh dng d i n tdi uli DR,.^.
Phia trai ciia gia tri hieu suat CL/C dai (ri^gj thi hieu suat se giam dan do ma sat dng tang len vi dudng kinh dng dan nhd laJ. Phia ben phai ciia ri^ax. hieu suat cung giam di la do anh hudng ciia sir tri/dt ve td'c do, nghTa la do chenh lech td'c do gjira pha ran va chat Idng (nude) tang len. Ly do la cd sU tang len eiia lu'dng khi yeu d u QK (chinh la
CONG NGHIEP MO SO 2-2010
KHOA HOC VA CONG NGHE MO
he sd cap khi >|/K tren dd thi) cho thiet bi bdm Airiift.
NghTa la irng vdi diem cd hieu suat cUc dai se cd gia trj cUe tieu ciia he sd cap khi yeu cau vj/K^m.
TUdng irng vdi cac sd lieu da dUa vao tinh toan cho he thdng bdm Airiift nay, ta nhan dUde:
DR,.^=530mm, nmax=28,6%; v|;K,™n=15.
3. Ket luan
•:• PhUdng phap tinh toan he thdng thiet bj bdm Airiift d tren cho phep lUa chgn dUde dudng kinh dng d i n van chuyen chat ran phii hdp de khai thae khoang san d sau dudi nude;
•:• Cdng thirc (16) va dd thi hinh 2 eho phep xac djnh lUdng cap khi yeu d u phii hdp vdi lUdng hat ran can phai van chuyen trong he thdng thiet bj bdm Airiift;
•:• Cdng thirc (18) va dd thi hinh 2 se xac djnh dUde hieu sua't can thiet va cUe dai ciia he thdng bdm Airiift diing de khai thae va van chuyen khoang san d dudi day bien hoac d dp sau dudi nude nao dd.D
TAI LIEU THAM KHAO
1. Nguyen Dire Sudng, Vu Nam Ngan. Giao
trinh May thiiy khi. Trudng Dai hoe Md-Dia chat. Ha Ndi 2001.
2. Gerd Grabow. Hydro-pneumatischer und hydrauliseher Festoffransport in vertikalen Rohrieitungen. Neue Bergbautechnik. 11 Jg. Heft 8. 1981.447-452.
3. Vergleicch hydropneumatischer und hydrauliseher Forderverfahren zur Gewinnung von Kies-sand-Gemisehen. Neue Bergbautechnik. 15 Jg. Heft 12. 1985.471-475.
4. Meerestechnik. Einsatz des Airiift-Verfahrens und der hydraulischen Forderung mit Kreiselpumpen auf der Grundlage von Ahnlichkeitszahlen. Seewirtschaft, Beriin 19, 1987.
Ngudi bien tap: Dao Dae Tao
SUMMARY
The paper introduces some study results using three phase streamline in the airlift pumping method to transport the solid materials in the deep under water.
BAI TOAN DIEU KHIEN
(Tiep theo trang 11) 3. Ket luan
Tren ca sd nghien ciru, tinh toan ly thuyet va xay dung md hinh thuc nghiem nhdm tae gia da thu duge kit qua tit, dugc kilm tra qua chay thuc t l tren md hinh thuc nghiem.
Dua tren phin mIm Protool V6.0 cua hang Siemens, mgt giao dien giam sat va van hanh cung da dugc xay dung (hinh H.3) giiip eho qua trinh thao tac van hanh dugc thuan tien.
Vdi cac kit qua dat dugc nay, nhdm tac gia tilp tuc phat triln d l eho phii hgp vdi mdi trudng san xuit cua nganh cdng nghiep gily, thay t h i cho cac bd dilu khiln khdng cdn chinh xac.O
TAI LIEU THAM KHAO
1. Hoang Minh San. Ca sd he thing dilu khiln qua trinh. Nha xuit ban Bach khoa. Ha Ndi. 2006.
2. Hoang Minh San. Mang truyin thdng cdng nghiep. Nha xuit ban Khoa hoe va Ky thuat. Ha Ngi. 2001.
3 Nguyen Doan Phudc. Ly thuylt dilu khiln tuyIn tinh. Nha xuit ban khoa hoe va ky thuat. Ha Ngi 2007.
Ngudi bien tap: Dao Dae Tao
SUMMARY
The article will present research results on theory in a problem on accurate position control. Therefore, the algorithm on position control and experimental models in the laboratory are develoiDed. The experimental model is developed based on Ijasic components of a control system which includes: a Human Machine Interface HMI (Protool V6.0), a PLC S7-200, and the bad drive system.
KHAI THAC DA XAY DUNG
(Tiep theo trang 31) Ngudi bien tap: Ho Sy Giao
SUMMARY
Binh Duong province locates In the important economy zone in the North part of Vietnam. This province has riche natural resources. Out put of the construction stone in the 2009 year is 14,020,000 m l The paper shows the state of the construction stone exploitation and some solutions for development of this national industry branch.
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