KHOA HOC VA CONG NGIfl MO G K O I
CNM
CO SO LY LUAN VA THIET LAP SIT PHU THUOC
DAC TRUNG CUA QUA TRJNH LAN TRUYEN SONG KICH NO
TRONG DAY PHI DIEN
TS. HOANG CONG DjNH, TS. DAM TRONG T H A N G Vien Ky thuat Cong binh
H
e thdng kich nd vi sai phi dien duge Cdng ty Nitrd Ndbel eua Thuy Dien tim ra vao nSm 1970 va ngay sau dd nd da duoc ap dung rdng rai b cac nUde phat trien. He thdng nay cd ten goi qud'c te la "He thdng kfch nd vi sai Nonel" va duoc xem nhu mot edng nghe nd tien tien nhat b the ky XX. Tai nUde ta mai de'n n§m 1991 san pham nay mdi bat dau duoc Tap doan Orica Uc va Tap doan EDL cua An Dd gidi thieu va ufng dung 6 Viet Nam [1,2, 4].^Phuong tien nd vi sai phi dien duoc ap dung hieu qua khi thi cdng nd pha da hay pha dd edng trinh cu trong eac ITnh vUc khai khoang, qud'c phdng, xay dung,... MSc du vai nSm trd lai day nha may qud'c phdng Z121 ed dau tu mua day chuyen cdng nghe eua Trung Qude de san xua't cae phuong tien vi sai phi dien, tuy nhien co sd ly thuyet cua cdng nghe nay van la mot bf quyet eua nha san xua't. Vi vay de ed the dUa ra duoc eae edng nghe hop ly cho qua trinh san xua't, cung nhuviee nang cao hieu qua ap dung phuong tien nd vi sai phi dien trong thuc te thi can thie't phai nghien CLfu, giai thfch ban chat cua qua trinh kich nd trong day phi dien va thie't lap md'i quan he giua cac thdng so trong sdng kfch nd vdi thdng ky thuat cua day phi dien.
DSc tfnh CO ban cua he thd'ng kfch nd vi sai phi dien la mot he thd'ng sCf dung nguon n§ng luong nd tha'p de kfch nd kfp nd. Ngudn nSng \ugng nay dudi dang sdng nd ye'u duoc tao ra, duy tri va lan truyen trong mot d'ng day mem ben rong du'dc phu mot Idp chat nd d§c biet ben trong [1, 6, 7]. Cac thdng sd cua phuong tien phi dien hien dang san xua't theo day chuyen eua Trung Qud'c b Viet Nam la: day cd du'dng kfnh trong la 1,2 mm va dUdng kinh ngoai la 3 mm, ben trong cd trang mot Idp mdng chat nd heexdgel d§e biet vdi cd hat sieu min (1-^3 ^m) vdi khd'i luong thud'c nd la my=i2 mg/m (nhd hon so vdi mat do thud'c trong day nd thdng thudng khoang 1000 lan). Day dan tin hieu cd mot dau bjt kfn, cdn dau kia gan vao kfp, khi phfa dau day dan tfn hieu
bj kfch thfch bang dung cu khdi nd hay bang nd kfp nd khac, thi lan sdng nd dupc tao ra trong day dan va lan truyen trong day dan vdi td'c do khoang 2000 m/s vdi ap ILTC dau sdng du nho de khdng pha hong vd day va dij nSng lu'png de lam nd kfp phi dien.
1. Phan tich qua trinh hinh thanh song kich no trong lirong no dai va day phi dien
Trong thue te dang bie'n ddi quan trpng nha't cua chat nd chfnh la sU kfeh nd, ma dSc trUng cua nd la sU truyen phan ufng nd dpc theo khd'i thudc vdi mpt td'c dp sieu am gpi la sdng kfch nd. Sdng kfeh nd la tdng hoa eua sdng xung kfch va vung phan d'ng nd chuyen dpng tie'p sau m§t sdng lan truyen trong khd'i chat nd. Vdi lupng nd dai (nhu day nd) be mSt sdng kfeh nd chuyen ddng vudng gdc vdi true cua lupng nd, chieu day eua m§t sdng kfch nd bang tdng chieu day cCia mSt sdng xung kfch va chieu day vung phan ufng hoa hpe. Chieu day nay rat nho trong dieu kien ly tudng cd the xem chieu day sdng kfch nd la bang khdng.
Dd'i vdi day phi dien vdi thude nd phu mSt ben trong cua d'ng, cung gidng nhu lufpng thude nd dang dng, khi phan ufng nd xay ra se hinh thanh mpt sdng xung kfeh manh cue bp ed dang hinh xuyen tai vung mat eat xay ra sU nd chuyen ddng tC/ thanh d'ng ve phfa tam d'ng, vi dudng kfnh trong cua day tfn hieu nhd, chung se giao thoa va hoa ddng vao nhau de tao thanh mdt be m§t sdng phing mdi chuyen ddng trong d'ng theo hudng kfch nd. Tfnh chat nay tuong tu nhu hieu ufng nd trong lupng nd dai hinh d'ng. MSe du chieu day cua Idp thud'c nho hon gia tn dudng kfnh tdi han cua nd khi nd ngoai khdng khf, nhiTng theo ly thuyet nd, khi qua trinh nd xay ra dd'i vdi lupng thud'c hinh d'ng se tao sU tap tmng n§ng lupng nd tap taing cao nha't chuyen dpng theo tmc cua d'ng [3, 5]. Tren hinh 2 md ta sU hinh thanh va lan tmyen sdng kfch nd trong day phi dien. Tai moi mSt cat ngang ludn xay ra hai hieu ufhg, hieu ijfng thuf nha't la sU lan tmyen m§t sdng nd cue bp hinh xuyen chuyen dpng tCr thanh d'ng
S 0 0 A I " G vi _
IJf.U'
CONG NGHIEP MO SO 3 - 2009
CNM
KHQ^IOC VA CONG NGHE MOday ve tmc eua day tfn hieu phi dien, chung giao thoa va hoa ddng vdi nhau de tao thanh m§t sdng nd mdi.
Tie'p theo m§t sdng nay tie'p tuc chuyen ddng lan tmyen trong day theo hudng kich nd gpi la hieu ung hai. Khi lan tmyen sang vi tri mdi be m§t sdng kfch nd nay gay kfch thfch phan ufng nd tren thanh d'ng va tie'p tuc hinh thanh m§t sdng cue bp hinh xuyen... Su lan tmyen m§t sdng nd nay gpi la sdng kfch nd trong day phi dien. Nhu vay qua trinh hinh thanh va lan tmyen sdng kfch nd trong day tfn hieu phi dien la mpt qua trinh xay ra lien tie'p dan xen hai hieu ung neu tren.
H.1. Suhinh thanh va lan truyen sdng kich no trong day phi dien: 1 - Be mat sdng no cue bd hinh xuyen chuyen ddng td thanh d'ng day ve true cda day phi dien, tai diem A; 2 - Be mat sdng kich no trong day phi dien tai diem B sau khoang thdi gian (t2-ti); 3 - dng day phi dien.
Phan tfch tren chi ra rang qua trinh kfch nd trong day phi dien ve co che tuTong tuf nhu qua trinh kfch nd lupng nd dai cd mat dp thud'c nho. Vi vay de ed the don gian md phong qua trinh lan truyen sdng nd trong d'ng day d i n tfn hieu, ed the coi d'ng day phi dien ehCra chat nd vdi mat dp bang mat dp thud'c nd tfnh binh quan tren toan bp the tfch ben trong eua dng day du'pc xae djnh theo cong thufc sau:
Po m^
V,
4m ^
(1)
' y "-^t
Trong dd: my - Khd'i lupng thudc no phu tren mpt don vj chieu dai cua day phi dien; Vy - The tfch tru rdng ben trong day cua mpt don vj chieu dai tLfong ufng; d, - Dudng kfnh trong eua day.
De cd the khai thac SLf dung va dieu chinh dupc chat iLfpng, thdng so ky thuat cua san pham trong qua trinh ehe tao thi can thiet phai thie't lap du'pc md'i quan he giua thdng so trong sdng kfeh nd vdi cae thdng sd ky thuat eua day d i n tfn hieu.
2. Thiet lap moi quan he giiira cac tham so tren mat song kich no vdi cac thong so dac tinh ky thuat cd ban cua day phi dien
Nghien curu qua trinh hinh thanh va lan truyen sdng kfch nd cua lu'png nd dai nhdi trong mpt d'ng khdng bj pha hoai va sCf dung eac djnh luat eo ban la djnh luat bao toan khd'i lupng, djnh luat bao toan xung iLfpng, djnh luat bao toan n§ng lu'png va nguyen li thuf hai nhiet dpng hpe eho phep nhan duoc cac quan he giufa cae thdng sd trong sdng kfch nd [1, 3]:
• Gia tri ap sua't binh quan tren m3t sdng kfch nd:
X+1 •Po-D ;
• Mat dp tren mSt sdng kfch nd:
- (X+1)-Po . X+Po-b
(2)
(3)
• Td'c dp hat san pham chuyen dpng sau m§t sdng kfch nd:
X+1 .D. ,4,
• Td'c dp am lan truyen trong san pham nd ., _X + Pob
X + 1
-.D, (5)
Vi gia trj b thdng thudng nho hon 10"^ va gia trj mat dp thud'c nd binh quan trong d'ng tfn hieu phi dien la po=10,6 kg/m^, vi vay tfch po.b trong cac edng thure tren (2, 3, 4, 5) rat nhd so vdi 1 nen ed the bo qua, khi dd cae thdng sd sdng kfch nd trong day phi dien cd the md ta nhu sau:
Gia trj ap sua't binh quan trong sdng kich nd dupe xae djnh ti^ (2):
P. = 1
X+1 •Po-D^ 4m>,
't(x+1)d, -D . (2') Mat dp san pham nd trong sdng kfeh no dLfpc xac djnh tii (3):
X+1 4(x+1)m
P g = — P o - (3-)
X X-d,
Td'c do chuyen dpng cua san pham nd sau mSt sdng kfch nd dufpc xac djnh theo (4):
U g ~ D g . (4') x+1
Td'c dp am lan truyen trong san pham kfeh nd xac djnh theo (5):
X
x . ^ - (5')
Phan tfch md'i quan he giufa eae tham sd tren m§t sdng kfeh nd vdi cae thdng sd dSc tfnh ky thuat CO ban cua day phi dien chl ra rang: ap IUc nd binh quan trong sdng kfeh nd ty le thuan vdi binh phuong td'c dp kfch nd va mat dp thudc nd trang trong d'ng day tren mpt met dai, ty le nghieh vdi dudng kfnh trong cua d'ng va he sd % (he sd nay phu thudc vao
CONG NGHIEP MO SO 3 - 2009
KHOA HOC VA CONG HQU MO « «
CNM
dSe tfnh nd cua day phi dien, can xac djnh bang thye nghiem. Khi mat dp Idp thud'c phu khdng ddi, ne'u dudng kfnh trong eua day phi dien cang ldn, thi ap liic nd trong day giam, dieu nay dan den td'c do kich nd giam nhanh de'n mpt gidi han nao dd thi qua trinh kfch nd bi triet tieu. Oieu nay rat ed )/
nghTa trong thUe te SLf dung va bao quan tranh de day phi dien bj dap, thung hoSe nUde vao thi qua trinh truyen kich nd khdng thUe hien dupe.
3. Tinh toan ap dung doi vdi day phi dien hien san xua't d nu'o'c ta
Hien nay viec san xua't he thd'ng kich nd phi dien b ta dua tren ed sd eae edng nghe mua hoan toan tCr nude ngoai, nhieu sd lieu thupc ve bf quye't nen chung ta khdng cd, tham chf ehung eung khdng dupe cdng bd tren eae tai lieu nude ngoai, vi vay trong bai bao da sCf dung eae sd lieu ky thuat thuong pham de tinh toan thCr nhu td'c dp truyen nd Dg=2000 m/s, m§t dp thude tren met dai, dudng kfnh trong. Cae sd lieu khac tam sCr dung de tinh toan so bp nhu he sd x=^ ,26 vdi thudc nd mat dp thap, ap dung edng thu'c (1) va td (2') de'n (5') ta cd:
Mat dp mat dp binh thude nd tinh binh quan tren toan bp the tfch ben trong eua d'ng day: po=10,6 kg/m^; ap suat binh quan trong sdng kich nd Pg=163.10^ kG/m2=1630 kG/m^; mat dp san pham nd binh quan trong sdng kfch nd Pg=19 kg/m^; td'c dp chuyen dpng cua san pham no sau mSt sdng kich nd Ug=885 m/giay; td'c dp am lan truyen trong san pham kich nd ag=1500 m/giay.
Thdi gian tac dpng cua tai trpng nd trong vung phan iing nd len day phi dien [1]:
T = -^ = M O l = i,5.io-6,S (6) w 2000
Trong dd: 5 - Chieu day Idp thudc phu trong day phi dien, 5=(1+3 i^m), td'i da la 3; w - Td'c dp di chuyen cua mat v§ng, trong trudng hpp nay ed the lay bang tdc dp lan truyen sdng nd, D.
Tri sd xung rieng cua nd tac dung len thanh d'ng la [1]:'
i = p.r=163.10^1,5.10"^ =
= 24,5kG.s/m2 =24,5.10-^kG.s/m2.
Ket qua tinh toan trj sd eua eac thdng sd sdng kich nd trong day phi dien, nhan tha'y m§c du gia trj ap sua't binh quan tren mSt sdng kfeh nd vudng gdc vdi day phi dien rat Idn, nhUng vi thdi gian va xung rieng tac dung len day rat nhd, nen day phi dien khdng bj pha huy sau khi truyen nd.
4. Ket luan
Qua trinh lan truyen kich nd trong day phi dien chi la mdt dang dSc biet cua day nd. Nd cd the hiiu
nhu mdt loai day nd cd mat dp thud'c nd rat tha'p, cung gid'ng nhu mdt d'ng ben rong chufa chat nd dang khi b trong. Tuy nhien day phi dien da ke't hpp hai hoa giufa cau tao eua day nd thdng thufdng vdi d'ng chufa khf nd d cho tao ra mdt mat dp thude nd tha'p nhd viee phan bd chat nd dSe biet tren thanh dng, SLf dung hieu Lfng "dudng dng" de tao phan dng hoa hpc va co hpc ve sii lan truyen kfch nd vdi td'c dp tha'p. Md'i quan he giua thdng so ky thuat eua day phi dien vdi eae thdng sd cua sdng kfeh nd lan truyen trong day phi dien ehi la mdt dang dSc biet eua lupng nd dai vdi mat dp phan bd thude rat nho, gid'ng nhu thude nd dang khi. Tren co sd eua cae mdi quan he thie't lap eho phep cd the thie't ke, dieu ehinh eac thdng sd ky thuat eua day phi dien phuc vu mue tieu ehe tao mdi phu hpp theo yeu cau cua thue tien.n
TAI LIEU THAM KHAO
1. Dam Trpng Thang, "Giao trinh Cdng tae nd tap I". Bp TUldnh Cdng binh. Ha Npi 2002.
2. Dam Trpng Thang, "Nd min vi sai bang he thd'ng kfch nd phi dien". Tap chf KHCN Cdng binh.
So 09, thang 01/2002.
3. ct), A BayM, K.fl CiaHiOKOBMH, B. H LUexrep.
0M3MKa Bspbiea. rocyflapcTBeHHoe naflaTenbCTBO cbM3MK0-MaTeiviaTH<HecK0M nmeparypbi, MocKaa 1975.
4. B. H. KyryaoB. PaspymeHne ropHbix nopofl
BSpblBOM - B s p b l B H b i e TeXHOnOrUM B npOMblUJneHHOCTVI.
M r r y , MocKaa, 1994.
5. r. M TIOKpoBCKuPi. BapbiB. Heflpa, MocKBa 1980.
6. Blasting guide. Orica explosives. Australia 1889.
7. Produce catalogue. Explosive consultation and application PTE LTD. Singapore. 1995.
Ngudi bien tap: Hd Sy Giao
fe SUMMARY
None! detonation system Is being large used in explosion works for military and civilian, however base the detprration theiory do not have In any documents. Analyse of exist and transmission of detonation wave In Nonel cord as like as detonation in the explosive pipe is investigate in this article.
Application of this theory base^allows to set up dependence basic parameters of
;detonation wave on the technic parameters o f Nonel cord.
CONG NGHIEP MO SO 3 - 2009
