KHOA HOC-CdNGNGHg
Xac dinh khoi Irfcfng vat lieu van chuyen trong thung tron be tong xi mang hai true nam ngang
• ThS. NGUYEN VAN THUYEN
• PGS. TS. NGUYEN VAN ViNH
• PGS. TS. NGUYEN DANG Di|n/I Trudng Dgl hgc Giao thdng v$n tai
Tdm tat: Bdl bdo trinh bay tdm tdt cdch xac dinh khii lugng vdt ligu vdn chuyen trong thung trgn bi tdng xi mdng (BTXM) hai trgc nam ngang theo 3 phUdng, dd Id: Vdng theo vo thung trin, dge theo trgc trin vd ndng len cao de hda trgn vdi nhau.
Tii khoa: Mdy trgn be ting, khoi lUtfng vgt lidu, vo thung trdn, phUdng ngang, qua trinh trin.
Abstract: This article presents a summary of how to determine the quantity of movement material in concrete mixing drum which has two horizontal axes according to three methods, namely: The circles In the mixing drum, the horizontal following the mixing shaft and lifting materials up In order to mix together.
Keywords: Concrete mixer, quantity of material, mixing drum, horizontal, mixing process.
1. Ddt vin d l
Cdng suit din ddng bd may trdn BTXM hai tryc nim ngang, phg thudc vdo nhieu yeu td nhU:
Sd lupng cdnh trdn, gde nghieng cua bdn tay trdn, td'c dd quay cfla tryc trdn; ngodi ra nd edn phy thude vdo eip phdi trpn, khdi IQpng cfla tQng m l trdn... Cd nhilu cdch de xdc djnh edng suat efla ddng cd din ddng bd mdy trdn BTXM hai trge nam ngang, chdng hgn: Xde dinh cdng suit dga vao edng tidu hao d l van chuyen hdn hpp be tdng dpe tryc trdn (kieu vft tdi); xae djnh edng suit dpa vao lge edn cdt, lyc ma sat giQa ede canh trdn vdi vdt iidu trdn; xdc djnh edng suit dga vdo cdng tieu hao d l ndng vd vdn ehuyin vdt lieu trong thung trdn... Trong khudn khd eua bai bdo, nhdm tde gia trinh bdy cdch xde djnh khdi lupng efla vdt lieu van chuyin theo^cdc phUdng trong thung trdn.'tQ do ldm cd sd de xdy dyng cdng thQc xac dinh cdng suit tieu hao cfla ddng ed dan ddng bd mdy trdn BTXM hai tryc nim ngang do Viet Nam' che tao'.
2. Npi dung
2.1. Cau tgo vd nguydn /y Idm vigc eua bg mdy trgn nghidn ctfu
Bd mdy trpn nghidn cQu la bd mdy trdn BTXM hai tryc nam ngang, Idm vide kilu ehu ky. So do nguyen ly elu tgo cua nd dQpe trinh bay d Hinh 2.1
l-0dd,2- Tnjc tr0n: 3 - V6 thiing tr^n; 4 - Banh ting din ding.
5 - H0P giim iffc; 6 • Ofng ca di$n, 7 - CSp binh rSng in ktidp ngoJi, e - B^ truyin dai. 9 - Bin tay tr^n: 10 - Canh tay trdn; 11 - COa xi vii li^u
Hinh 2.1: Sd di nguyen If cau tgo eua bg mdy trgn BTXM hai trge nam ngang (dung ticli 1m^ do Vigt Nam chi tgo)
2.2. Md td qud trinh dl chuyen cua hgt v$t iigu trong qud trinh bi mdy trgn lam vl$c
Theo [4], trong qua trtnh bp mdy trdn Istfn viee, cdc hgt vdt lidu trong thung trdn se thyc hi|n cdc chuyen ddng ehfnh nhu sau: Vdt lieu chuyen dpng dpc theo trge trdn do edc bdn tay trdn diJi^c bd tri mdt gde nghidng a so vdi tryc trdn; vat ligu chuyen ddng vdng theo v6 thung trdn do cdc ban tay trdn mang di trong qud trinh quay trgc trpn; vSt lidu bj ndng len eao vd hda trdn vdi nhau^do cac bdn tay trdn d hai trgc tron bd trf rigupc ehieu nhau vd chuyin ddng quay ngUpe chilu nhau.
Cd t h i md td cac hgt vdt lidu ehuyin dfing trdn mdt mat phing nim ngang nhu Hinh 2.2d[i6\
ddy. Ddi vdi nhQng ban tay trdn tren eung mot true trdn cd hudng nhu nhau, thi hgt vat lidu se thiic hidn 3 ehuyin ddng, dd Id: Chuyen ddng tQ ban tay trdn phfa trude den bdn tay trpn phfa sau tren cung mdt trgc (mui ten dpc tryc), ehuyen ddng sang hudng cfla trye tron ddi dien dd Id chuyen ddng vdng (mui tdn ngang) vd ehuyin ddng ndng vdt lieu len cao (mui tdn cheo).
Ddi vdi nhQng ban tay tron dupe lap theo hudng nggde Igi vdi nhQng ban tay trdn ndu tr§ri (bdn tay trdn 5), thi hgt vdt lieu se thue hien 2 ehuyen ddng: Mdt chuyin ddng se day hat v^:
lieu ngupc Igi vdi ehilu chuyin ddng do 4 bdn tay trpn trudc nd tgo ra; mdt chuyin dpng sang hQdng efla trge tron ddi didn.
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KHOA HOC - CONG N G H £
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® ® Hinh 2.2: Sa do md ta qui Mnh Minh 2.3: Stf tfd md chuySn d^ng cua cAc cinh tr0n ta v$t //#u dl chuyin trong budng trgn (khong kS cinh trong m$t ph&ng nim vit IhOng tr^n) ngang (khdng kS cinh
vit thung tr^n) Trong so dd tren thi: I, II Id thQ tu ede trye trdn;
1,2, 3,4, 5 IdthQtg cdc bdn tay trdn tren mdi trgc tr^n; (p Id gde quay cua trgc trdn.
- Khi trgc trdn quay dupe gde cp = 45" thi vdt lieu se ehuyin ddng nhu sau: l,->l ; l,->ll,; l,->L; l4->IL;
>i3; II->ll,; Il3->l3; Il3->i;; Ii;->|^? | | ^ - > | / -Khi tn^c trpn quay dUde gde tp = 90°thi vdt lieu se chuyin dong nhu sau: L->L; I->ll.; I->ll • l'->lt,;
i4->i3; i4->ii4: i4->"i3: i5->i4: K->K K->K if,->iia;
ll,->l*; Il,->l3; II ->fl,; Il3->l3; |13->I,. = = " '^ ^ - Khi trgc trdn quay dUpc gde 9 = 135° thi vat lieu se ehuyin ddng nhu sau: L->L; I->II,;1->IL; I->ll,;
L->l,; L->ll • L->ll,. IL->II • 11->L; II->|-ll->|| • ll,->l,; Il^->r3; Il3->il,; Il3->t3; Il3->l^; ll^->ll^: l|^->r^.
- Khi tmc trpn quay dupc goc 9 = 180° thi vdt lieu se ehuyin ddng nhu sau: l,->l • li->ll,; V^IU U->ll,;
l3->l2: U->ll3; l3->IL; K->\^, L->IL; L->ir,. Tl->ll • ll,->l,; ll^->g I! ->ll3; |Q->I2: Il2->l3; tl^->ll,; Ilg->l
- Khi tn,ic trpn quay dUpc goe tp = 225° thi vdt lidu se ehuyin ddng nhU sau: L->IL; l,->ll,; l3->L; Ia->ll3;
1.->IL. IL->II • ll,->l •1l,->l • ll,->IL; IL->I • IL-
>^y \>K' K->^v "5->"4; i'5->'5-
-Khi tn,jc trpn quay dUpe goc tp = 270° thi vdt lidu se ehuyin dong nhu sau: 12->IU; l,->ll,; l3->l2; V^'U;
i3->ll • l,->l3; l,->ll,; r->tl3. II->ll • ir->l,; Fl,-
>l2; \->^^' K->^v "5->"4: "5->'r
-Khi tryc trpn quay dUpc goc tp = 315° thi vdt lieu se chuyin ddng nhg sau: lg->L; Ig->ll3; l3->ll2; l4">l3;
l^->ll • l,->ll3. II,->IL; IL->I • IV>r2; Il3->ll4; II3-
>i3; "3->i4; ii4->L; "4->is; "5->"4; ii5->is-
- Khi true trpn quay dupe gde tp = 360° (0°) thi vdt lieu se chuyen ddng nhu sau: l,->l2; l r > " i ; I3"
>i2; i3->!i3; L->ii2; i,->i3; i.->ii4: i4->"3; "5->"4; h'^K
\^->\\ \\^->\\;, \\^->\-, l l 3 - > \ ; l l , - > l , ; ll,->l5.
CQ sau mdt vong quay efla trge tron thi vdt li^u tgi mdt diem trong thflng trpn se dUpc quet qua 1 lin. Nlu eoi cdc cdnh trdn tren mot trye trdn dupe bd tri theo hinh xoln vft, thi sau mdt vdng quay cfla trye trpn vgt lieu se di chuyen bing mdt budc cfla hinh xoln vft. Sau mdt vdng quay efla trge trdn thi vdt lidu se djch chuyin dupe mot dogn bing mdt biide xoln vft S.
2.3. Xdc djnh lugng v$t ligu vgn ehuyin theo cdc f^tfdng trong qud trinh Idm viic cua bg mdy trdn
NhQ da phdn tfch d tren, cdc hgt vdt lidu se thgc hidn 3 ehuyen ddng, dd Id: Vdng theo v6 thflng trdn, ehuyin ddng dpe theo trgc trdn vd chuyin ddng ndng Idn cao.
So 4/2016 2.3.1. Xdc dinh khii lUtfng vgt lieu van chuyin vdng theo vd thtjng tron
Khi bdn tay trpn ehuyin ddng quay, se quet ede hgt vdt lieu thdnh mpt hinh vdnh khan theo phupng hiidng kfnh. Trong do, ban kfnh ngodi cfla hinh vdnh khdn ehfnh Id khodng each tQ tdm trgc trdn d i n diu mflt cfla bdn tay trdn r, khodng each nay xap xl bang bdn kfnh eua vo thung trpn; bdn kfnh trong efla hinh vanh khdn ehfnh Id khodng edeh tQ tdm trye trdn d i n mep trong cfla ban tay trdn a. Chilu day cfla hinh vdnh khdn se bing be rdng eua ban tay trdn theo phUOng vudng gde vdi ehieu ehuyen ddng b.cosa (Hinh 2.4).
^ ;>....
Hinh 2.4: Sd di tinh khii lUtfng vgt Uiu chuyen dgng theo phUdng vdng
Theo hinh ve, ta cd:
Dien tfch hinh vdnh khan do bdn tay trdn tgo ra khi chuyen ddng dupc xdc djnh nhu sau:
S, = 7t(r^-B').(m').
Trong dd: (1)
r - Khodng cdch tQ tdm tryc trdn den mep ngoai efla bdn tay trdn, (m);
a - Khodng edeh tQ tdm trgc trdn den mep trong cfla bdn tay trdn, (m).
The tfch hinh try do 1 bdn tay trpn cd be rdng b.cosa tgo ra Id:
V„=S,bcoso.(ni')- (2) Trong dd:
b - B l rong cfla ban tay trpn, (m); a - Gde nghieng cfla bdn tay tron so vdi trgc trpn, (dp).
Thay (1) vdo (2), ta thu dupe:
V^ =3i.(r'-a').b.cosa.(ni'). ,gj Moi mdt vdng quay cua trge trdn, se ed z bdn tay trdn quet qua, nen t h i tfch efla eae hinh try dupe tao ra sau mpt vdng quay se la:
= z.ji.(r^ -a').b.cosa,(iii^/vi
(4) Trong dd: z - Sd ban tay trdn trdn hai tryc trdn, (chile).
Thi tfch vat lieu vdn ehuyin vdng theo vd thung trpn do z bdn tay trpn quet qua trong mot phut dupc tfnh nhu sau:
Vfc = 2.ILE jr.(r^ -a^).b.cosa.(m^/phut).
(5) Trong do:
n - Tde do quay efla trge trpn trong mpt phut, (vdng/phut); E - He s d dien day eua thung tron, e
= 0,5.
Khdi lupng vat lieu do ede ban tay trdn quet dUdc trong 1 phflt dUdc xae dinh nhQ sau:
m,b = V^.p, (kg/phut). (6)
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KHOA HOC - CONG N G H i Trong dd:
p - Khdi IQpng rieng eua vdt lidu, (kg/m^).
Thay (5) vao (6), ta dQpe:
m.^ =zjiipn.Cr' - a ' ) b cosa,(k8/phui). (^) Vdi edeh tfnh tQdng ty ddi vdi ednh tay trdn, ta thu dupc:
= zji.e43.jL(a'-1;") b,, (kg / phut).
(8) Trong dd:
r, - Bdn kfnh eua trgc trdn, (m); b, - C h i l u day cua cdnh tay trdn, (m).
T d n g IQdng vdt lieu v d n c h u y i n theo phUdng vdng trong 1 phut dupc xde djnh nhQ sau:
m , = m,. + m,^, (kg/phut). (9) Thay (7) va (8) vao (9), ta thu dUpc:
m, =z.nip7t[(r--a^).b.cosa+(a^-r|').b|],(kg/phut). , J Q . 2.3.2. Xae dinh khii lugng vdt lieu vdn chuyen dgc theo tnjc trdn
Neu coi eae eanh trdn tgo thdnh mdt trge vft, cdn v6 thung trpn Id mdng vft. Theo [2], nang s u i t vdn c h u y i n vat lieu trong mdt phut eo the dupc xdc dinh nhu sau:
m2 = 60.F.v.p.£ (kg/phut). , (11) Trong do: F - Dien tfch mdt cat ngang efla ddng vdt lidu, (m^); v - Vdn tde vdn c h u y i n efla dong vdt lieu, (mjtaidy); p - Khdi liipn^ ridng efla vdt lidu vdn chuyen, (kg/m^); e - Hd so day mdng vft, e = 0,5.
- Xdc djnh dien tfch mdt c i t ngang efla ddng vdt lidu.
Do edc cdnh trpn khdng tham gia vdo qud trtnh vdn c h u y i n vdt lidu theo phuong dpe trge, ma chl CO cac ban tay trdn ddt nghidng mpt gde a mdi tgo ra c h u y i n ddng dpc tryc efla vdt lidu.
VI vdy, ta ed the eoi e h i l u ddi efla cde cdnh trdn ehfnh Id bdn kfnh cua "tryc v f f , trdn "trgc vft" do ed g i n ede eanh vft la edc bdn tay trdn. Do d d , dign tfch mat cat ngang cfla ddng vgt lieu trong mdng vft ehfnh b i n g didn tfch hinh vanh khdn do bdn tay tron va cdnh tay trpn tgo ra vd dupe xdc djnh nhu sau:
F = 7t(r^-a^)T,(m=) / 1 2 J Trong dd: r - Khodng cdch tQ tdm cfla tryc trdn (tryc vft) d i n d i u mflt cfla bdn tay trdn, (m);
a - Chieu ddi cfla cdnh tay trdn (bdn kfnh cfla trge vft), (m); T - S d true vft trong budng trpn, T = 2 .
- Xae djnh vdn tde vdn c h u y i n efla vdt lidu trong mdng vft, ta c d :
v = |2,(m/giay). ^^^^
Trong do: 8 - Budc vft, (m); n - Tde dd quay cua trgc vft trong mot phut, (vdng/phut).
Thay (12) vd (13) vdo (11), ta xde dinh dQdc khdi IQpng vat lieu van e h u y i n dpe theo tryc trdn trong 1 phut dd Id:
iiij=T.7iS.npe{r- -a^),(kg/phut). ^.j^s 2.3.3. Xdc dinh lu<?ng vdt lidu dtfpc ndng Idn cao trong qua trinh trdn
Hinh 2.5: Sd di xac dinh khoi itftfng v$t li^u trin mit ednh trgn ^
Mdt cdch g i n dung, ed the coi the tfch vdt li^u tren mdt ednh trdn ed dgng la mdt hinh chdp (Hinfi 2.5). Trong dd: p - Gde ehdn ndn efla vdt ll^u tr§n ban tay trdn, (do); H - Chieu cao efla hinh chdp, fm);
a - C l i i l u dai cfla ednh tay trdn, (m); r - Khodng edeh tQ tdm trge trdn den d i l m mQt cfla bdn tay tron, (m);
r, - Bdn kfnh efla trye trpn, (m); b - B l rflng bdn tay trdn, (m); a - Gde nghieng efla bdn tay trdn so vdi trye trpn, (dd).
T h i tfch cfla hinh chdp dupe xdc djnh nhu sau:
^HS,.(m^). (15)
Trong dd: S^ - Didn tfch tam gidc ddy efla hinh chdp, (m^).
Xde dinh didn tfch tam gidc ddy efla hinh chop $„:
(16) 1. x,(m').
S , = | ( r - r , ) . b .
Xdc djnh c h i l u cao cfla hinh chdp H:
H = ^ ^ ^ , ( m ) . (17) Thay (16), (17) v d o (15), ta dupe t h i tfch
vdt lieu dupe n d n g len b d i 1 c a n h trpn sau m^t v d n g quay:
^(r - a)(r - r,).b.tgp.cosa,(m' /v6ng) (18) Tdng the tfch vat lidu do z cdnh trdn ndng Ifln dupe sau mdt vong quay se Id:
-z.(r-a)(r-ri)i.tgpcosa,(m'/v6ngl. (19) Khdi IQpng vdt lidu dQpe ndng Idn sau 1 phOt cfla z cdnh trdn dQpe xdc djnh nhu sau:
m,=V„pn,(kg/phiit), (20) Trong d d : p - Khdi IQpng ridng efla v$t li^u,
(kg/m^); n - So vdng quay cfla trge trdn trong 1 phflt, (v6ng/phQt).
Thay (19) v d o (20) ta dQpe:
•nj =—z.pJib(r-a) (r-r,>.i#.cosa,(kg/phui) ^21) TQ (10), (14) vd (21), ta thu dUpc:
Tdng khdi lupng vat lieu van e h u y i n theoca 3 phuong trong 1 phut se Id:
m = (m, + m + m3), (kg/phut).
T i Id % khdi IQpng van c h u y i n cua v$t liflu theo tQng phUdng K, dupe tfnh nhu sau:
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K H O A H O C - C O N G N G H I
Trong dd: m^- Khdi IQdng vdt lieu vdn ehuyen theo phuong i (i = 1-f3), (kg).
De t h u ^ n Ipi trong qua trinh tfnh khdi lUpng vat lieu v d n c h u y i n theo ede phuong trong thung trdn, nhdm tde gid da x d y dgng ehgong trtnh tfnh todn dUa trdn p h i n m i m Visual Basle 6.0; sQ d y n g ehuong trinh d d x d y d u n g dUdc d l tfnh todn v d i bo mdy trdn B T X M hai t r y c ngang, dung tfch thflng trdn 1m^ do Viet Nam c h l tgo, trong qua trinh tfnh toan, tde gid da sQ d y n g edc thdng s d c u a cap phdi vdt lidu c h l t g o mde be tdng C30/38,5, phye vg thi edng t u y e n d u d n g s i t trdn cao ga Ha Ndi - Nhdn [3].
Hinh 2.6: Giao di$n eua ehUdng trinh tinh khii iugng v$t Ugu van ehuyen theo edc phtfdng trong buing trgn BTXM hai trgc ngang, dung tich thiing trin Inf do Vi$t Nam chi tgo
Bang 2.1. Ti 1$ % khii lugng vgt li$u vgn ehuyen theo 3 phtfdng
T T
1 2 3
Ky
•n, m.
m,
Khii luTDg vSt Iifu v|n cbayin tbto 3 phinrng Irong 1 phot (kg/phdl)
35967.2 20865,6 510.6
Khii luyne v#l litu v|n cbnyen (h» 3 phinniG (%)
62,72 36.39 0.89
So 4/2016
Tiep tge nghien cQu, khdo sat khdi IQdng vat lieu c h u y i n ddng trong thflng trdn B T X M hai trgc n a m ngang theo thdi gian trdn, bang each sdn m a u hat vdt l i ^ u , sdng phdn logi, edn dong chflng trong ede giai dogn trdn khdc nhau •
Tai ii$u tham khdo
[1]. Vu Liem Chfnh, Nguydn Kiem A n h , Nguyen Thi Thanh Mai, Dodn Tdi Ngp, Tran Vdn T u a n , Nguydn Thidu Xuan (2013), May vd thiit bi san xuat vdt Hdu vd cau kidn xdy dtfng, NXB. Xay d g n g .
[2]. Nguyen V a n Hpp, Phgm Thj NghTa, Ld Thidn Thdnh (2000), Mdy tri^e vdn chuyen, N X B . GTVT.
[3]. C d n g ty T N H H edng nghidp DAELIM (2014), Thiit ke cap phii bd tdng si 1, DU d n : T u y e n dudng sat do thj trdn eao, dogn G a H d Ndi - Nhdn.
[4]. ^nrp (2004), n^mw.m!ixir^m.mu.
^mn. xmm±^m'^>c, ^ ^ ^ # , ^m. (Tiing
Vidt Nam: VUdng V d Trung (2004), Nghien ctfu thtfc nghidm qua trinh Idm vide cOa mdy trdn hai true, Ludn vdn Thac sy ky thudt, TrUdng Dai hpc Trudng A n , Trung Qude).
N g a y n h $ n b a i : 25/02/2016 N g a y c h i p n h a n d a n g : 15/3/2016 NgUdi phdn bidn: TS. N g u y i n Dinh TQ
T S . Nguyen Lam Khanh
3. Ket lugn vd ki^n nghj
- Bdi bdo da trinh bdy tdm tat each xdc djnh ti 10 % khdi lupng vdt lieu v § n chuyen theo 3 phUdng trong thung trdn B T X M hai trye nam ngang; d d dp d y n g cdng thQc de tfnh toan ddi vdi bd m a y trdn BTXM hai trgc n a m ngang dung tfch thung trpn 1m^ do Vidt Nam c h l tgo. K i t qud tfnh toan eho t h i y , khdi iupng vat lidu vdn c h u y i n vdng theo vd thung trdn Id ldn n h i t (62,72 % ) , cdn khdi IUdng vdt lieu dUde ndng ldn cao la nhd n h i t (0,89 % ) ;
- Kien nghj dp dgng cdng thQc trdn, de tfnh tl 10 % khdi luting vat lidu v d n e h u y i n trong budng trdn B T X M hai trge nam ngang, tQ do Idm cd s6 d l xdy d g n g edng thQc xdc djnh edng s u i t tidu hao efla d d n g c d d i n ddng bd may trdn BTXM hai trgc n i m ngang do Vidt Nam c h l tgo;
79