KHOA HQC - CONG NGHE KET QUA NGHIEN CUU Bp PHAN CAT THAI Mm LIEN HOP VOfi MAY DAP LUA N H A M KHAI THAC HIEU QUA RUM SAU THU HDACH OT VIET NAM Nguyin Van Tam ', Li Minh Lu ^, Nguyin Xudn Thiit ^ TOM TAT Theo irdc tinh moi ndm cd mrac cho khodng 46.305 triiu tdn ram (ram vd rg), luang ram ndy din phdn nhieu vdn bi coi la phe phdm, bi dot hogc virt bd trin dong rugng Viec ndy ldm d nhiem mdi truang vd gdy lang phi rdt ldn nguon tdi nguyin Nghien cuu bg phdn cdt thdi ram liin hgp vai mdy dgp liia nhdm tgo thudn lgi cho cdc phuang dn xir ly ram da dugc Ihuc hien tgi khoa Ca - Biin, Hgc vien Nong nghiep Viet Nam Bdi bdo giai thi0u khdi qudt ve cdc kit qud nghien cicu vi ram tuai vd bd phgn cdi thdi ram lien hgp vdi mdy dgp lua nhu: dgc diim ca ly tinh cua ram tirai cho qud trinh cdt thdi bdng cgnh sdc dao: lua chgn nguyin ly cat cho bgphgn cdt thdi ram de ddng lien hgp vdi mdy dgp lua; xdy dung bien dgng cgnh sdc dao ddp ung cdc chi tieu ve cdt thdi tren ca sd ly thuyit cua qua trinh cdt thdi bdng cgnh sdc dao vd xdc dinh toi uu mgt so thong sd chinh ciia bg phdn cdt thdi rcmi lien hgp vdi mdy dgp lua Cdc kit qud nghiin ciru ndy da bo sung mgt dgng daa mdi vd mot nguyin ly cdt mdi cho bg phdn cdi thdi ram de ddng liin hgp vdi cdc mdy thu hogch IUa, dong thdi ldm ca sa cho cdc cdng trinh nghien ciru khac lien quan din ram tuai vd bgphgn cdt thdi cdc vdt lieu tucmg tyr Tir khod: Mdy thu hogch lua; mdy bdm thdi ram; bg phgn cdt thdi ram; dao cat; cgnh sdc dao RESULT OF A SCIENTIFIC STUDY ON THE STRAW CHOPPING PART COMBINED WITH THRESHING MACHINES FOR THE EFFICIENT EXPLOITATION OF STRAW AFTER RICE HARVEST IN VIETNAM Nguyen Van Tam ', Le Minh Lu ^, Nguyen Xuan Thiet ^ SUMMARY An estimated approximately 46.305 million tons of rice straw and stubble was produced nationwide every year that is considered as waste therefore it was burned or leave immediately in the field This causes the environmental pollution and leads to a massive waste of agricultural resources In order to facilitate the straw processing, a study in straw chopping part combined with threshing machineswas conductedat the Faculty of Engineering, Vietnam National University of Agriculture This paper presents an overview ofthe study results on fresh straw and the straw chopping part combined with threshing machines involved characteristics of fresh straw for cutting process by an edge; the selection of principles for the straw chopping part to combine easily with threshing machines; the establishment ofthe edge profile to meet the targets on chopping based on the theoretical basis of the cutting process by the edges and determining optimal parameters ofthe straw chopping part combined with threshing machines.The results of this study completed a new knife along with a new cutting principle for the straw chopping part to combine easily witli threshing machines; simultaneously, the resuh is also a basis for further study on fresh straw or similar materials Keywords: rice harvester; chopping machine; chopping part; cutting knife; edge L DAT VANDE Viec nghien cuu cdc bg phan cdt thai cho cac vat lieu nao do, trudc hdt can nghien cuu vd cdc ddc didm Uen quan vd co ly tinh cua vdt lieu cdt dua tren co sd qua trinh cat thai bang canh sac dao O day nghien cinx vdi vat Hdu cat dgng thd sgi la rom tuoi, vdy vide xac dinh mdt sd ddc diem ca lytinh cua ram tuai la can thiet Ddi vdi mdi bp phgn cat thai, dieu kien lam 'Truimg Cao ding CO gi*i Ninh Binh ^•^ Hoc vien nong nghiep Viet Nam T"^ ==6 ^ huomg dSn viec lira chon nguyen ly cat phu hop cho muc dich nghidn CUU Nhu da TAP CHi CONG NGHIEP NONG THON - SO 19 - 2015 15 KHOA HQC - C N G N G H | : bidt, d cac co sd san xudt ndm; lam phdn vi sinh; lam go cdng nghidp thi ram dupc tap trung vd mdt dja didm cu thd vd thudng dugc cdt vdi cac nguyen ly cdt dang truydn thdng nhu dao chuydn ddng tdm kd cd dinh (nguyen ly cdt dang dao dSa hogc dao dgng trdng), vdi nguyen ly thi rom dugc giii cd dinh trdn bd mat tam kd va da dupc nen ep trudc dugc cat Song, vdi bg phdn cdt thai ram Hen hpp vdi may dap lua thi cd didu kidn lam viec nguge lgi vdi khdi rom dugc cdt theo cac nguyen ly truyen thdng la rom ludn d trang thai ddng, khdi ram dupc tung tiJr cua cua may dap lua vao bp phgn cat, do can lira chpn nguyen ly cat cho bd phdn cat thai ram phii hop lidn hpp vdi mdy dap lua Khi lien hop vdi may dap lua, bd phdn cdt thai rom cdn dam bdo cdc chi tidu thidt ke dua tren co sd ly thuydt ciia qua trinh cat thdi cdc vdt lieu thd sgi bang canh sac dao [8,9], De dam bao cac chi tidu thidt ke, kha nang lam vide cua bg phdn cat thai rom phu thudc vao nhieu thdng sd, dd bdn thdng sd vdo dnh hudng chinh dupc lira chgn la: van tdc cat v(m/s); lupng cung cap q(kg/s); gdc kep x(do) va khe hd giua dao va tdm kd (canh ggt) 6(mm), hai thdng sd la: chat lupng cat Cx(%) va chi phi nang lugng rieng Ne(kW.s/kg) Do vdy, de ndng cao kha nang lam vide lien hgp bd phdn cdt thdi vdi may ddp lua, ngoai cac chi tieu thidt kd thi can xdc dinh cdc gia tri tdi uu cho cac thdng sd dnh hudng chinh (thdng sd chinh) dugc nghien cuu II PHU'ONG PHAP NGHIEN ClTU 2.2 Phuwng phSp nghien cuu there nghiem Bd phgn cdt thdi CTR-1 dupc nghidn cuu thuc nghiem vdi thdng sd vao va thdng sd gpi la hai ham chi tidu chdt lugng cdt Cx va chi phi nang lupng ridng Ne dugc xac dinh theo cdng thiic sau: Cx = 100-^,%;A^^, =^,kW.slkg Trong do: - mcd la khdi lupng ciia khdi ram cdt dat c6 chidu dai cac cpng ram < 10 cm; - mmr la tdng khdi luong cua khdi ram ldy mdu tir khdi rom sau qua bd phdn cdt; - N|b la cdng sudt trung binh tren true trdng cdt vd q la lupng cung cap ram vao bg phdn cdt Phuong phap nghidn ciiu thuc nghidm dua tren: phuong phap quy hoach thuc nghiem don ydu td; phuang phdp quy hoach thuc nghidm da ydu td va phuong phap tdi uu hda tdng quat [2] De nhdn kdt qua nghien ciiu thuc nghidm cdn co cac dung cu va cdc thidt bi Dd va ghi nhgn ket qua vd mdt sd dac didm CO ly tinh cua ram tuoi, cac thidt hi va dung cu: Cdn didn tii METTLER TOLEDO, Cdn ddng hd Nhon Hda 5kg, Tu sdy FN 500P, Dung cu dp Iuc nen Dung cu luc cat, Thidt hi ma sat GUNT, Dung cu ap lire nen dat tren mdy keo nen van nang AUTOGRAPH-AGS-20KNG, Dung cu luc cat dat trdn may keo nen van nang AUTOGRAPH-AG S-20KNG Dd xac dinh chi phi nang lugng cdt cdn he thdng thidt bi md men va cdng sudt: Cam Phuong phap nghien cuu dupc lua chpn: ket bidn quang OMRON E3F-DS10C4; ddu hpp giiia nghidn cihi ly thuydt va nghien cuu momen KSM SDIOOOQA va bp thu thdp xu 1^ thuc nghiem sdliduDEWE-3010 2.1 Phirong phap nghidn cmi ly thuyet in KET QUA NGHIEN ClTU Phuang phap nghidn cuu ly thuydt dupc 3.1 Nguyen ly cdt thai cho b$ phan cat nghien ciiu dua trdn; co sd ly thuydt cua qua thai rom trinh cdt thai bdng canh sdc dao [7,8,9]; toan hpc Vdy dd tan dung va khai thac rom, dupc gidi tich; mpt s6 phuong phdp toan hpc co triet de hon, cdn nghien ciiu bd phan cat thai hpc ndng nghiep [l] va phuang phap md hinh rom cd nguyen ly phii hgp Hen hpp vdi may dap Ilia Vdi cac bo phdn cat thai sii dung cac hda md phdng he thdng ky thugt [d] nguydn ly cdt truydn thdng dao chuydn dpng 16 TAP CHl CONG NGHIEP NONG THON - SO 19 - 2015 KHOA HOC - CONG NGHE tdm kd cd dinh nhu: nguydn ly cat kidu dao dgng trdng va nguyen ly cdt kidu dao dgng dia [?] thi cau tao ddi hdi phai cd cgp 16 cudn va ep khdi rom trudc khdi rom dupc dua vao hgng thai, lam cho kdt cdu truydn dgng va kdt cdu chung cua bg phgn cat rat phiic tgp lidn hgp bd phgn cat voi may dap Iua, trdn ca sd kdt hpp vdi trang thdi khdi ram dugc tung true tidp vao bp phgn cdt thai, nhdm tac gid da iua chpn dugc nguyen ly cdt phii hgp lidn hgp bd phan cdt thai dugc trinh bay trdn hinh Ciia rOm B6 phan cit thdi rcfm MO hinh lifin hdp b6 phan cat rom vdi m^y dap lua Hinh Bo phgn cdt thdi ram vd mo hinh lien hap vai mdy ddp lua 1-Trdng cit; 2-Canh gat (tim ke); 3-Than dao c6 dinh; - Tam lien ket; -Thanh ldp dao De thdng nhat tdn gpi, tac gia ky hidu tdn sac dang cong dugc thiet kd cho qua trinh gpi cho bp phdn cdt thai rom cd nguyen ly nhu cdt cd trugt, cac dao cd djnh dugc lap vdi cac tren hinh Id "bp phdn cdt thai CTR-1" la cgnh sac cua dao song song vdi va khodng "nguyen ly cat kidu nhieu dao cd dinh" each giiia hai mat bdn cua hai dao kd Id bd Bd phdn cdt thai CTR-1 gdm cd: Trdng cat nhd dan dang hinh tru cd chidu ddi la Lt, ban kinh mat Nguyen ly hogt ddng: Khi rom dugc tung ngoai la rt, tren trdng cat lap ba hang canh gat tir ciia ciia may dap liia, lugng ram dupc each ddu nhd Hen ket giiia ma Hen kdt tung true tiep vao cira vao ram ciia bd phgn cdt cua hang canh gat va mat tru cua trdng cat bang thai, nhd canh ggt khdi rom dugc dua vao bu long Hang canh ggt dupc cau tgo bdi cac viing cat va dupc ep trdn canh sdc cua luai dao canh gat ldp song song, ddng phdng va each vdi mdt dp luc cat can thidt, khdi rom sau ddu trdn tam lien ket 4, cdnh ggt la thep dugc cat nhd cdnh gat tung khdi ram da dupc tdm ddy 0,004 m, rpng la beg, dai la Leg va dupc cdt ngoai qua cira cua bd phan cat thai rom Idp nghidng mgt gdc a so vdi phuang hudng Uu diem cua bd phan cdt thai CTR-I:, kinh tgi chdn cdnh ggt Dao cd dinh cd cgnh + Thuc hidn nguyen ly cat cd trupt, de dang TAP CHI CONG NGHIEP NONG THON - SO 19 - 2015 17 KHOA HQC - CONG NGH|: cdt cac vat lieu thd, sgi vd lam cho chi phi ndng lupng cdt cd gia tri nho + Canh gat ldp nghidng mpt gdc a cho phep vira keo (va) ram vao vimg cat, nen ep va gat khdi rom trupt trdn canh sdc dao, ddng thdi tung nhiing phdn rom da dupc cdt ngoai + Nhd su lien hop vdi bp phan dap liia da tan dung ngudn ddng ndng ciia khdi ram tir cira cua bd phdn dap Iiia dugc tung thang vao bd phdn cdt thai CTR-1, qua dd da lam giam chi phi nhdn cdng cho qud trinh cap lieu cat rom Ddng thdi rom dugc cat sau bd phdn dap la rom tuoi, ndn chi phi nang lupng cat giam dang kd so vdi cat khdi rom khd tgi co sd san xudt + Cd the thay ddi chidu dai doan cat bang each thay ddi bd rdng idp dao va cdc hang cdnh gat Nhugc diem cua bd phdn cat thai CTR-1: Khdng cat dupc nhiing cpng rom cd phucmg song song vdi cgnh sdc dao, song thuc td rdt it nhiing cpng rom ma toan bd chidu dai than cgng ram ddu song song vdi cgnh sdc dao Be khde phuc nhupc didm nay, theo yeu cdu chidu ddi dogn cat ma chpn khoang each giiia hai dao kd bd cho phu hgp 3.2 Ket qua ve mot so d^c didm co' ly tinh cua rom tirffi voi giong lua BC15 Lua sau ggt de xdp ddng khdng qua mpt ngdy, ddc tinh co ly ciia rom bao gdm: dp am; khdi lugng rieng; he sd ma sat giira rom vd thep; quan hd gifta ap luc nen qn(N/cm^) va ty sd nen ep e; quan he giira gdc trugc T va dp Iuc cdt thai ridng qci(N/cm) hoac cdng cdt thai ridng vd quan he giOa ap luc nen ben q^b (N/cm^) vdi khe hd khdi ram da dupc cat chen vao khe hd tgo bdi mat ben cua dao va mat ben canh ggt Cac ket qua nghien ciru da dupc trinh bay cu thd theo tdi lieu lidn quan [4], dd mdt sd kdt qud nghidn ciiu ndi bat nhu sau: - Quan he giiia ty s6 ep tuang ddi Sn va dp lire ep qn ddi vdi rom tuoi: Gpi ap luc nen ram Id q„'y N/cm^ hr la chidu cao ban ddu cua khdi ram d trang thdi tu nhien; hn dogn giam chidu cao khdi rom nen, dd ty sd nen tuang ddi dupc dinh nghia theo cdng thirc: s„=-^ Kdt qud thi nghidm quan he giua ap lire nen qn (N/cm^) va ty sd nen tucmg ddi En the hidn tren dd thi hinh Ob thj quan hee -q„ q^jtN/ar^^) Hinh Dd thi ihirc nghiim vd dd thi hdm hdi quy md td quan hi E„ - g„ TCr sd lidu thi nghiem qua phan tich hdi quy, ham hdi quy md ta quan he giiia ty sd nen tuong ddi En va dp Iuc nen qn vdi he sd tuong quan R^ - 0,9693 nhu sau: En-0,1644.ln(qn)-0,1335; (1) - Quan he giiia gdc trupc x va dp lire cat thai ridng qct hay cdng cdt ridng Ar dupc trinh bay trdn dd thi hmh hodc cdc cdng thitc (2) vd (3) Do t h j quan he qct - T : -0 8045*; - Tidfl} i D&th|quan h ^ A r - T = lE-05x' • OOllx^ + 0-0287»i + 1.4493 R^ =0,9717 M y^gS-^V-aj // l^rmin+6%Armir) - ' ^ \ ^ j Armin — " -^Jg^ i ,T{fl6) Hlnh S\(phu Ihudc cua qa va A, voir 18 TAP CHi CONG NGHIEP NONG THON • SO 19 - 2015 KHOA HOC - CONG N G H £ £Jcf= 87,65-0,8045 T;jV/cm fl= = 0,9245; (2) i^=10-5.T3-0,0011.T^0,0287.T-1-1,4493; i?2 = 0,9717; (3) Tir kdt qua trdn va phuang trinh (3) cd the thiet kd dao thai cho qua trinh cdt cd cdng rieng nhd nhdt hoac tuong ddi nhd, theo [7] gia tri gdc trupt T dupc ldy cho cdng cdt thdi ridng Acr nam khoang tir Acrmm ddn Acr = Acrmin+ % A c ^ n = 1,45J/cm^ voi A „ = 1,45 J/cm^ thay vao phuong trinh (3) dupc hai gia tri gdc trugt imin = 43'^ va Xmax = 67° Trdn dd thi hinh khoang tir x^m "^ tmax la vung gia tri gdc trupt hgp ly cho cdng cat ridng cd gid tri tuong ddi nhd Vdy thidt kd bp phdn cdt thai theo nguyen ly cat kidu nhidu dao cd dinh gdc trucrt hpp ly duoc thidt kd khodng T = 43''^67^ - Quan he giira dp luc nen bdn qnb va khe hd dupc nghidn ciiu thi nghiem vdi muc khe hd khac cho ket qud trinh bay bdng dd thi hinh va cdng thiic (4) q^b = -18,915.6 + 146,38; (N/cm^) ; (4) vdi 5< mm; dd: khe hd cd don vi; mm qnbCN'cm') Dd thi quan he Qnt - Hinh Anh hudng cita khe din q„h Nhgn xet: Vdi cac kdt qud nghidn cuu tren, da xdc dinh dugc mpt sd dac didm lien quan vd CO tinh ciia rom dnh hudng ddn qua trinh cdt ram: quan he giua gdc trupt vdi ap lire cdt thai rieng va cdng cat ridng; quan he giiia khe hd ciia dao va tara ke vdi luc ma sat cua khdi ram da dugc cat tac dung Idn thdnh bdn ciia dao Kdt qua nghien ciiu cho thdy, vdi nguydn ly cdt kidu nhidu dao cd dinh, canh gat chuydn ddng ggt va nen khdi rom trupt trdn canh sac dao, gdc tru'pt T = 43 -^ 67 la vimg gdc trugt hop ly cho cdng cat ridng Acr tuang ddi nhd Do dnh hudng ciia lire ma sat vao bdn ciia dao, chd tgo bd phan cdt thai rom theo nguyen ly khdng nen chpn khe hd 6< mm, khe hd cd thd chgn ^ a nghidn cim viing = -f mm 3.3 IVlQt so ket qua nghien cihi ly thuyet - Kdt qud xdy dung bidn dgng canh sdc dao: Vdi mdi nguydn ly cat nhdt dinh, bidn dgng canh sac dao cd anh hudng ldn ddn chdt Iupng cat va chi phi ndng Iugng ciia bd phdn cdt: Mdi mdt bien dang cgnh sac dao dugc thiet kd che tao, xet vd mat khoa hgc khdng chi dam bdo didu kien cat tdt, md cdn ddi hdi phdi cd radt ban thuydt minh vd co sd tinh toan ndng Iugng cho bd phan cat thai Vdi cdc dao Iam vide d cac nguydn ly cdt truydn thdng dang dao trdng va dgng dao dia dd dao chuydn ddng thi rad hinh khao sdt tinh toan ndng lugng cho bd phdn cdt da dugc rapt sd tac gid [7] trinh bay cu thd Ddi vdi bg phdn cat thai rom CTR-1 lidn hgp vdi may dap lua cd nguyen ly cdt trinh bay tren hinh thi canh sac dao cd dang cong, canh sdc hudng vd phia Idm, cdnh gat nghieng mdt gdc a so vdi phuang hudng kinh ciia trdng cdt, qua trinh cat se tao hai loai gdc la gdc quay trdng cdt (p va gdc cue (hinh 5) Hmh Mo hinh xdc dinh hdm vec to bdn kinh cue R(6) lheo goc quay rp Viec khao sat xac dinh chi phi nang Iugng bd phdn cdt thai dugc thudn Igi klii ban kinli cue TAP CHi CONG NGHIEP NONG THON - SO 19 • 2015 19 KHOA HQC - CONG N G H $ R(e) dugc xac dinh Voi nguyen ly cat nliieu dao CO dinh neu su dung biSn dang c£inh sic dao co dang cung tron lecll tam tlii viec xac dinh R(G) theo goc quay cat rat phurc tao va gan nhu idiong xac dinh dugc, ben canh diSu Icien trugt g cuoi dai d o ^ cat khong dugc thuan lgi tlic la goc trugt x ty IS thuan vol chieu dai ban kinh cue R(0)[5] De khac phuc mgt so van de tren, bien dang canh sac dao cho bg ph^n cat thai CTR-1 da dugc xay d\mg theo bien dang duong xoan 6c logarit co dac di§m g6c trugt x khong d6i qud trinh cat dugc trinh bay tren cong thiic (5) RC((.)= R„,r'-"«=