KHOA HOC - CONG NGHE NGHIEN CIJU, THIET KE VA CHE TAO MAY SAY HAT TUAN HOAN CO GIAI OOAN U TRUNG GIAN Chu Vm Thiin' TOMTAT Bui buo giai thieu kel quu nghiC'ii cuu thiel ke va che lao thiet hi say thap tuan hoan co giai ctoaii ii tmng gian di sdy thoc, ngo vu tirang Mot mdy say ihdp vdi kel cdu Ihdp Iru ludn hodn ngoai, Ihdo lieu h^ dong hoc da duac linh todn ibih ke vu chi luo gdm cue bo phdn: Hailo dot song song cd dien tich ghi lu 0.14 mV 16: Ihi lich buong ddi 0.25 m^ Thiel bi sdy gdm thdp sdy idm viec song song: Dudng kinhx chiiucao moi thdp Id 1.9 m x 5.4m: Budng phdn phdi itdy Ihdp cd dm'mg kinh x chieu cuo Id 1.9 x 1.2m: Khoi luang thdc chda cue dui mot Ihdp Id 5200kg Qua_ ihu nghidm sdy lltdc ngo vd tuang thay rdng: Co the xa todn bo nguyen lieu khoi mdy sdy khdng cdn phdi [ao dong thu cdng vu khdng he bj dai vdo thdnh mdy: Vdi nguyen li?u co dd dm ban ddu dudi 18% cd the sdy hat co ddo hode khdng cdn ddo mu dd dm cua hat lai cdc vi tri cua thdp vdn tirang ddi deu Vdi hat co dm > 22% cjud trinh sdy bdt buoc phdi CO ddo: Qud Irinh sdy cd giai doan ii ldm gidm chi phi sdy dong thdi tdng dong deu dm cuu sdn phdm Bieu ndy cd the gidi thich Id nhd cd giai dogn it khdng cdp nhi^t nhung qud trinh di chuyen dm tit ldm hat van dien kel thdc giai doan u qud trinh sdy se dat hieu qud cao han: Chi phi ndng luang di turn bay mgi K^ hai nude sdy hai co dg dm ban ddu tim han 20% nhd han 1.3 kWh/KgHlO Id thdp so vdi cdc mdy sdy hien cd Tir khoa: Sdy dgng to dot than dd dg dm ddo hat RESEARCH, DESIGN AND MANUFACTURE A RE-CIRCULATING GRAIN DRYER WITH TEMPERING Cliu Van Thien' SUMMARY The paper shows the research results with design and manufacturing of a vertical re-circulating grain dryer for drying of paddy, maize and soybean Dryer has a re-circulation component and a pneumatic grain discharging system Heat supplying source is a two-burning chamber coal furnace with a grate area of 0.14 m and burning chamber volume of 0.25 m' each There are vertical drying bins with dimension of outer diameter x height of 1.9 x 5.4m each can contain a paddy amount of 5200 kg Drying air distribution chamber is in the bottom with diameter x height of 1.9 x 1.2m Drying tests with paddy, maize and soybean indicated that material is discharged easily without manual labour, and grain is not stuck into drying wall After drying of grain with initial moisture content of less than 18%, grain moisture contents at different positions were relatively even regardless of turning grain upside down or not Grain with initial moisture content of > 22% there must have some turnings of grain Tempering during drying helps to reduce drying cost and also increase the grain moisture uniform This can be explained that during tempering without heat supplying, moisture continue to move from internal to the outer surface of grain, so moisture is easily evaporated in the next drying step Energy consumption for evaporation of one kilogram of moisture is less than 1.3 kWh when drying grain with initial moisture content of above 20% with tempering This energy consumption is lower than that of existing dryers Keywords: Dr> ing, pneumatic, coal furnace, moisture content, grain turning I TONG QUAN Hien nay, cac may sjy hat (lua ngo, dau dS) a nuac ta chtl yeu la tnay say tinh vi ngang Uu dtem caa may say tinh vi ngang la gia va pham khac nhau, it bi dao tron nen cac hat it hi giy vo, gia nguyen d u a c phoi sau siy Song, nhugc dilm co ban la su phan b6 tac chl phi say thap, co the say duoc nhieu loai san nhan siy khong d6ng dSu tren dien tich san siy, 'TS Vien Co dien nong nghifpva Cong nghp STH '^"^ '^^° ^^ *° L, ^ho khong dong dSu Phai daO TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 KHOA HOC - CONG N G H E nhieu lan va thdi gian say dai, viec vao san pham thucmg phai thuc hien thu cdng, khd ca giai hoa Trong cac nuac phat trien, chu yeu su dung may say hat tuan hoan Hen tuc nang suat rat ldn May say hat tuan hoan cd cau tao chung bao gdm budng say hinh tru hay hinh lang tru dung dugc gpi la (thap) Vat lieu dd vao thap phia tren Khi ndng thdi vao tu phia dudi hoac thdi cat ngang chieu chuyen ddng cua vat lieu Trao ddi nhiet giira tac nhan say va vat lieu say phan ldn la ddi luu cuong bite, lam viec lien tuc hoac chu ky Tuy theo dang vat lieu-sSy va trang thai am cua nd ma cd the sir dung cac phuang phap di chuyen vat lieu khac thap Hien nay, tren the gidi su dung phd bien cac phuang phap di chuyen vat lieu nhu sau: Vat lieu rai tu thap; Vat lieu roi thap va dugc khdng che bang cac vat can; Vat lieu dd day thap va dugc khdng che tdc di chuyen bang lugng vat lieu lay dinh ky hay lien tuc; va vat lieu di chuyen thap nhd cac ca cau co dac biet tir tren xudng, tdc dp di chuydn dugc khdng che bdng lugng vat lieu idy Khdng ndng dugc dua vao qua nhumg "mang cap" dat thap xuyen qua ldp vat lieu day khoang 90 -^ 100 mm va di vao "mang xa" ngoai Tdc dp qua lap hat thudng tir 0,2 -^ 0,6 m/s va cd thd Ian han Tuy vay neu tdc dp ldn qua se lam bay hat Vi vay, tdc dp khdi mang xa thudng khdng qua m/s va tiiy thudc vao loai hat dem say Phuang phap dau tien diing de say cac vat lieu ma chu ydu la thoat am tu nhu mudi quang sit , thai gian say rat ngan ; Phuong phap thu va thu sir dung nhidu dd say cac vat lieu hat nhu: Thdc, ngd, my hat ca phe ; Phuang phap cudi ciing thudfng dung cho cac loai vat lieu nhu: Banh da thai, my dng, my sgi, dira n^o Trir phuang phap dau tien, cac phuong phap sau vat lieu say di chuyen cham, thdi gian sdy dai (cd the ddn hang chuc gid) May sdy tudn hoan lam viec theo chu ky vat lieu van chuydn nhanh han d may sa\ lien tuc, nhung nhd dugc luu chuyen tuan hoan nen thdi gian sdy cd thd keo dai phu thudc vao dp am va tinh chdt nguyen lieu ban dau Hien tren the gicri thudfng su dung mdt sd kieu may s.h tuan hoan nhu sau [1,2,4,6,8] 1.2 May say thap tru tuan hoan May say thap tru tuan hoan the hien tren hinh d may say tuan hoan dang thap tru tuan hoan trong, vat lieu say dugc chiia pheu d phdn tren ciia thap, dugc phan phdi sang hai ben va chay xudng phia dudi Khi ndng dugc quat gid thdi vao d phia dudi thap, chuyen dpng len phia tren va xuyen qua ldp vat lieu thoat ngoai Vat lieu chay xudng duoi dugc \ it tai van chuyen ngoai va dd vao pheu chiia vat lieu Nhu vay vat lieu Hen tuc chay theo mang dan lap di lap lai nhieu lan cho tdi dugc say khd May lam viec theo chu ky L l May say thap tuan hoan kieu mang Mas sdy thap tudn hoan kieu mang the hien tren hinh Ci may sdy tuan hoan kidu mang, vat lieu sdy dugc dd vao day thap va di chuyen Hinh Mdy sdy thdp ludn hodn kieu mdng Uu diem cua may say tren la: San pham sau say cd dp ddng deu dp am cao; Tdc dp giam am Idii va cd the dieu chinh dugc; Cd kha nang ca gidi hoa khau vao, va dao trpn nguyen lieu; Say dugc cac loai san pham dang hat; Trong qua trinh chuyen hat tu tren xudng dudi, hat dugc chuyen ddng dich ddc va tidp xiic vdi ddng kill d vi tri khac vdi nhiet dp khac TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 41 KHOA HOC - CONG N G H E nen chdt lugng hat dugc cai thien Song, nhugc didm: Viec nap, thao lieu va qua trinh sdy dugc dao lien tuc bang vit tai nen de gay vo hat; Khd lam sach may hoan toan nen de gay lan hat May cd the say dugc cac loai hat khac nhu lua, ngd, ca phe hat, lua mi Dp ddng dh\i vd dp dm cua san pham say cao Hat it bj vo, nut De kiem tra, de ve sinh, tranh hien tugng 1^ hat qua trinh say va de che tao, phii hgp vdi didu kien nude ta hien Nhd nhirng uu di8m cua may say thap tru tuan hoan ngoai ciia hang Kongskilde (Dan Mach) ma chiing tdi chpn mh may de nghien ciiu, thiet ke, che tao va thuc nghiem quy trinh say tuan hoan hat cd giai doan u trung gian de chuyen giao vao san xuat Hinh Mdy say thap tru tudn hodn 1.3 May say thap tru tuan hoan ngoai thao lieu bang dong May dugc che tao bdi hang Kongskilde (Dan Mach), thd hien tren hinh Nguyen lieu dugc gau tai dua vao khoang khdng gian giiJa dng tam va vd ngoai may say Khi ndng sau hda vdi khdng dugc quat day vao dng tam, tgi day dugc phan deu xung quanh, qua ldp hat dd lam khd, sau dd dugc thdi ngoai Trong qua trinh say, hat dugc say hoac u theo yeu cau cdng nghe Viec dao trpn nguyen lieu nhd gSu tai, cd the thuc hien lien tuc hoac theo chu ky Dac biet, bp phan thao lieu ket thuc me say d day cd cau tao kieu ranh phan khi, quat tac nhan say ddng thai la quat tao ddng de thao lieu ket thuc Nhd thao lieu kieu ddng ma vira thao dugc triet de, vira giam dugc dang kd chieu cao cua may Bdng I Mgt sd dgc tinh ky thugt chinh ciia mdy Lopi mfly Dung lich (m') Nang sual (Tan/me) Luu lupng (m'kk/m^h^l/h) 1332 1701 1194 1565 1069 1432 20/24 7.1 5.7 20/30 8.6 6.9 20/36 10.2 8.2 Tone cong suat nhi^t (kcal) 60 000 80 000 60 000 80 000 60 000 80.000 Thdi gian say (h) 4.6 3.4 5.5 4.1 6.6 4.9 Hinh Mdy sdy thdp tru tudn hodn ngodi Ihdo lieu bdng dgng II PHl/ONG PHAP NGHIEN CUU La mau may mcri, tien tien, d Viet Nam chua cd Vi vay, de rut ngan qua trinh nghien Cliu, chiing tdi da lira chpn phuang phap nghien Cliu ly thuyet tir cac ngudn thdng tin cap nh$t dugc va qua cac tai lieu tham khao, ddng thdi ket hgp chuyen giao cdng nghe cua cua hang Kongskilde (Dan Mach), la hSng ndi tieng nhat chuyen ve thiet ke va che tao cac thiet hi HI KET QUA VA THAO LUAN He thdng thidt bi sdy dugc thidt ke the hien tren hinh Bao gdm Id ddt than, ndng sau hda vdi khdng ngoai trdi dat nhiet dp yeu cau dugc quat (3) thdi vao budng say Nguyen lieu dugc dua vao may say nhd gau tai (9) De giam vd hat, giai doan ddu can dd hat qua CO cau giam chieu cao dang dich dac Khi hat da dugc dd tren 1/3 chidu cao thap, nguyen lieu dugc dd vao tam thap va phan phdi deu thap say Khi ndng sau qua dng tam, qua ldp hat dd lam khd hat sau dd dugc day ngoai Trong qua trinh sdy, hat dugc sdy hoac u TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 KHOA H O C - CONG N G H E theo yeu cau cdng nghe Viec dao trdn nguyen lieu nhd gau tai (9) May sdy cd the say dugc khdi lugng san phdm vdi chidu cao Idp hat khac nhd nut gid (6) Hinh Sa mdy sdy thdp tru ludn hoan ngodi thdo lieu bdng dong l.L6d6t;2 Bu6ngh6akhi:3.Quat;4 Ong khoi; 5, 6ngd5n tac nhan sa\; Nut gio; 7.8 Ong dan; Gau tai; 10 Sito chira 3.1 Ket qua tinh toan va lu'a chpn mot so thdng so chinh ciia may [3,5,7,9, 10] Vat lieu say: Thdc cd khdi lugng rieng Pv = 550 kg/m^ - Tdc dp giam am trung binh: N = 0,75-l%/h - Tac nhan say (TNS): Hdn hgp khdng voi khdi Id - Nhien lieu ddt: Than kip Ie - Tdc dp gid qua ldp hat: v = 0,24 m/s - Nhiet dp cua TNS trudc vao vimg say: tl = 40-42"C - Dp am ban dau cua VLS: o)| < 24% - Dp am sau say cua VLS: 0)2 "= 12% Sau tinh toan theo cac buac ciia [1.2,3], xac dinh dugc cac thdng sd ca ban cua may say nhu sau: + Lo dot song song co dien tich ghi la 0,14 mV Id; thd tich budng ddt 0,25 m^ + Thiet bi say gdm: thap say lam viec song song; Duomg kinh x chieu cao: 1,9 m x 5,4m; Budng phan phdi day thap: duang kinh X cao: 1,9 x 1,2m; Khdi lugng thdc chua cue dai thap: 5200kg; Quat tac nhan sdy: 16000 m^/h, 160 mmHzO, ddng co 15 kW, Tdc dp: 1450 vdng/ph; Thung chiia: gdm thung dung tich chiia 7,5 tdn/thung + Thidt hi van chuyen dang gdu tai: Nang suat: tdn/ h; Cdng sudt ddng co dien: 1,1 kW, 1450 v/p 3.2 Ket qua nghien ciru thvc nghiem 3.2.1 Cdc chi tieu cdn xdc dinh a) Dieu kien mdi trudng: Tslhiet dp khdng dugc bang nhiet ke thuy ngan va nhiet ke dien tir; am khdng dugc bang am dp Testo 635 b) Dac diem nguyen lieu: Dp sach cua nguyen lieu (%), khdi lugng 1000 hat dugc xac dinh theo TCVN.1700-86; Do dm (%), dp ddng deu dp am (%), ty le hat trdc va, ty le hat ran nut (%), ty le mam dugc xac dinh theo TCVN 6616-2000 c) Chat lugng san pham: Dugc danh gia qua cac chi tieu nhu phan (b) d) Danh gia tinh nang cua may: Nang suat may (tan/h) dugc tinh toan theo thdi gian Iam viec thuc te; Tieu thu nang lugng cho mdt dan vi san pham (KJ/kgH20) dugc tinh toan thdng qua bang tieu thu nhien lieu va cdng suat say theo TCVN 6616-2000; Chi phi lao ddng true tiep cho I dan vi san pham (ngudi.h/tdn), tdc dp thoat am (%/h) dugc thuc hien bang quan sat bam gid.; Lugng thdc (ngd) mac tren budng say (g/lan say), lugng hat ton du (g/ ldn say) dugc thu nhan va can e) Ndng dp bui (g/m"*) dugc danh gia theo TCVN 5740-1993 Dp dn cua may (dB) dugc xac dinh theo TCVN 3150-79 3.2.2 Quy trinh cong nghe sdy hat So dd quy trinh cdng nghe the hien tren hinh Cac buoc cua quy trinh cdng nghe say hat cd giai doan u trung gian dugc tien hanh nhu sau: ] Chudn bl nguyen lieu: Can dugc say so bp den dp am khoang 22 - 24% sau dd dugc iam sach sa bd; ddi vdi ngd bap sau say ddn dp am 18 - 22% dugc dua vao te bdp, lam sach sabd TAP CHI CONG NGHIEP NONG THON - SO 12 - 2014 43 KHOA HOC - CONG N G H E Sdy giai dogn ihirc hien dm hat tic IS den dmri 13%: Nhiet dp tac nhan sdy ddi vdi thdc: 42"C; ddi vcri ngd: 42"C; ddi vdi tucmg: 40"C Giai doan kdt thuc dp dm hat dat dp am bao quan (13%) Thdo lieu md cira xd thdc vdo mieng gau tdi de chuyen vdo silo: Viec thao lieu cd thk thirc hien quat tac nhan say hoat ddng hoac tat, song cudi qua trinh xa lieu cdn cho quat chay de xa het lieu khdi may Viec tao ndng dugc thuc hien nhu sau: Than dirge dua vao Id ddt, ndng dugc hiit qua budng hoa khi, tai day ndng dupe hoa vdi trdi dam bao nhiet dp ciia tac nhan sdy Viec dieu chinh nhiet ciia tac nhan sdy cd th^ thuc hien bang each md van gid didu chinh lugng lanh hoa vao hoac dugc didu khi^n tir ddng qua he thdng ddng md quat Id Ngp lieu: Nguyen lieu dugc dd vao mieng gdu tai qua dng dan vao may say Trong giai doan dau nguyen lieu dugc dd vao dng giam tai Khi nguyen lieu dd day 1/3 thiing say, gat van nap lieu de nguyen lieu dd vao may say Qua trinh nap lieu tu ddng dimg lai thdc ddn rale bao miic ciia thiet bi say Sdy giai dogn I thuc hien dm ciia hat tir 24% den 18% : Nhiet dp tac nhan say: ddi vdi thdc: 40°C; ddi vdi ngd: 40"C; ddi vdi dd tucmg: 38''C Tdc dp giam am ciia giai doan khoang 0,6^ 1,0%/gid Giai doan I ket thuc dp dm hat dat 18% •I Ddo Iron vd u: Viec dao trdn va ii cd the thuc hien theo each sau: Md cua cho nguyen lieu chay vao gau tai, nguyen lieu dugc dd trd lai d tam may hoac nguyen lieu dugc dua vao gau tai va chuyen sang sild chua Sau li 4h nguyen lieu dugc xa trd lai may say Than — • Ddt than ^ Khi Id 1» Khdng Hoa + Quat Id Ng lieu Gau tai • • Sdy GDI Nap vao may i Sild chira ' Buong chua de dao tron vau * Hinh Sa dd quy trinh cdng nghe sdy hat co giai doan it trung gian Dgt 3: say 450 t i i nguyen lieu co 5ni tir 21,5 + 22%, sky xudng dp am 13% KSt qua trinh bay tren bang b) Say ngo: Loai ngo PACIFIC va LVNIO; Nhiet dp moi truong 28 * 34 °C; Am dp moi truong: 75 + 78%; c) Say dau fu-ong: Loai dau tuong VX93; Nhiet dp moi tru6mg:28+34 °C; Am moi truong: 72 -i- 79%; Ket qua trinh bay tren bang 3.2.3 Kel qud Ihirc nghiem a) Say thoc: Loai thoc: Khang dan; Nhiet moi truong: 28 -H ° C ; Am moi truong: 78 + 80% Qua trinh say dugc thuc hien: Bqi I: say 30 tan nguyen Heu co 4m tir 17,5% say xuong am 12.5 %; Dgt 2: say 40 tan nguyen lieu co Sm tu % , say xuong 5m 13%; 44 TAP CHf CONG NGHIEP NONG THON - SO 12 - 2014 KHOA HOC - CONG NGHE Bang Ket cjiid ihirc nghiem sdy thoc Thong so Loai nguyen lieu Trong lirpng say Nhiet dp say Do am hat: - Ban ddu - Sau say Thdi gian say Dao va il d dd am (ii gid) Dp gia tang ty 1? trdc vd Dp tang ty le lu'rt ne Chi phi nang lu"ang rieng Tdc dp gio qua ldp hat Ty Ie trdc vd va ran ntit gia tang cua gau tai Nang suat thiet bj tlieo SP khd (tinh quy ve dd giam am tir 20 -H 13%) )* Nong dp bui d vj tri lam viec tliudim xuyen Do on Don vi Kg "c % % h % % % Kwh/ksH20 m/s Khang Dan lOOlO 42"C 17.5 12.5 5,01 15 0.35 0,45 1.36 0,25 % Loai thoc Khang Dan 9870 40-42"C 22 13 9.1 18 0,37 0,55 1,29 0,245 Khang Dan 10600 40+42"C 25 13 12,5 18 0,38 0,55 1,22 0,24 0,44 0,45 0,5 tan/h 1,357 1400 1378 mg/m' 0.205 0,205 0,265 85 85 85 dB Bang Ket c]ud thuc nghiem sdy ngd vd tucmg Thong so Don vi Loai ngo vii tuong Loai nguyen lieu Ngo Pacipic Ngo LVnlO Do tirong VX93 Trong luffiifi say 10050 5020* 4900* Kg 38"C Nhiet TN say "C 42't 42"C 19 % 18.2 18 Dp am hat; - Ban dau 12.5 % 13.0 13 - Sau say h 6,2 Thdi gian say 15 15 16 Dao va u d am (u gid) % 0,26 m/s 0,26 0,265 Toe dp gid qua ldp hat 0,35 0,45 0.4 Dd tang ty le nut ne % 3,7 3.6 Kg/h 6,1 Tieu thy than da 64 114 78 kWh/rae Tieu thu dien 1.32 1,29 1,31 Nhiet luong lam bay 1kg hoi nude KWh/KgH,0 Ty 1? trdc vd va r^n nut gia tang 0,29 0,3 0.3 % cua gau tai 1,141 1123 1378 tan/h Nang suat thiet bi theo SP klio (tinh quy ve t^iam am tir 20 - 13%) )* Nong dp bui d vj tri lain viec thudng 0,205 0,12 0.265 mg/m xuyen 78 78 78 dB Dodn 3.2.4 Xdc djnh dnh hudng ciia qua trinh dcio Ilia den ddng deu dc) dm - Da tidn hanh say cd dao va khdng cd dao, dp dm hat cudi qua trinh say tai sat dng tam ( k> hieu W) va sat ngoai may say ( Wn) Do dugc tidn hanh tCr khoang (sat day may) den khoang (gan dinh may), mdi khoang i tri, tai mdi vi tri diem W va Wn Tien hanh say voi dp am ban dau khac nhau: 18% 22% va 30% Kdt qua dugc thd hien bdng dd thi tren hinh TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 45 jr2 KHOA H O C - C O N G NGHE Hinli Anh hudng ciia qua trinh ddo den dd ddng deu dm sdn phdm 20%, nhd hom 1,3 kWh/KgH20 la thap so vdi cac may say ma chiing tdi da timg nghien cuu, IV KET LUAN Da lira chpn dugc nguyen ly may say hat dua tren mau may say cua hang Kongskilde (E)an mach) vdi kdt cau thap hii tudn hoan ngoai, thao lieu bdng ddng hpc la phuong p h ^ thao lieu dam bao nang suat cao, khdng anh hudng ddn dp niit ne hat nhu phuong phap sii dung vi't tai hien cac may say dang sir dung Tinh toan, thiet ke, che tao va thux: nghiem vdi quy trinh say dao cd giai doan u trung gian Qua thuc nghiem da xac dinh dugc nang sudt thuc td cua may 1,14 -^ 1,4 tan/h tiiy thudc vao dp dm ban dau cua h^t, dp am can thidt phai dao tren 22%, dioi gian dao thich hgp la gidf Vdi che dp say thich hgp se cho san phdm cd dp ddng deu cao vdi dp chenh lee dp am san pham sau sdy la 0.5- 0.6% chi phi nang lugng rieng 1,3 kWh/KgHiG la thap so vai cac may sdy thap hien cd d nude ta nha cd giai doan u trung gian TAI LIEU THAM KHAO - Khi say cd dao dp am hat tai gan dng tam va phia ngoai may say chenh lech nhd 0.5- 0,6% Qua qua trinh thuc nghiem say gan 600 tan hat (ehu yeu 1^ lua), cd mdt sd nhan xet nhu sau: Khi say khdng dao, dp am hat tai gan dng tam va phia ngoai may say chenh lech la 0,8-1,% vcfi dp am ban dau la 18%; say hat cd dp am ban dau 22%, dp chenh la 0,8-1,4% va sdy hat cd dp am hat ban ddu 25%, dp chenh la 1-1,8%, - May say lam viec dn djnh cd thd sdy mdt sd loai hat ndng san vdi chat lugng cao Nang [I] Teter N I'atldy drjing manual Pood and Agricultun; Organisation of the UnilL-d Nutions i'AO Ayicuilural suat may dat 1, 14 ^ 1,4 tdn/h Services Bulletin 70 Itomi; 1987 - Hat dugc say tucmg ddi ddng ddu tai mpi [2] Thuy N.X, Choudhary, M.A and lampton J Cl The vi tri cua may, dp sai lech dp dm hat nhd, hoan elTccts of high drying tempcraiure and tempering on develdpmtni ol" stress eraeks and germination of maize beed (Zea mays L) toan cd the chap nhan dugc - Nhi?t dp tac nhan say dugc didu chinh Seed Scienee and Technology 27 1999'507-515 [3] Brooker D.B Bakkcr-Arkema F W and Hall C.W chinh xac Dp sai lech \ e nhiet dp ciia tac nhan 1992 Drying and storage of grains and oilseeds Van Nostrand Reinhold New York USA sdy 22% qua liru mgi phan thai Kj \eu "Cw - diijn hoa nong nghidp trinh say bat bupe phai cd dao vai van de cong nghiep hoa hiyn dai hoa nong nghi?p vu nong - Qua trinh say cd giai doan ii lam giam chi Ihon" Nam 1998.1 la Noi Viet Nam [10] Phan Hieu Hien CJrain and seed drying survey in phi say, ddng thcri tang dp ddng ddu am cua san phdm Dieu cd thd giai thich la nhd cd northern provinces Vietnam Agricultural Sector Programme Support, Seed Component DANIDA 2001 giai doan u khdng cdp nhiet nhung qua trinh di chuyen am tir tam hat van dien ra, kdt thuc Ngay n h a n bai: 18/02/2014 giai doan ii qua trinh say se dat hieu qua cao hon Ngay p h a n bi?n: 10/3/2014 Nguoi p h a n bien: TS Doan Xuan Thin, Hpi ca - Chi phi nang lugng dd lam bay 1,0 kg hoi nong nghiep Viet Nam nude say hat cd dp dm ban ddu lan han ^^ TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 ... dao cd giai doan u trung gian Qua thuc nghiem da xac dinh dugc nang sudt thuc td cua may 1,14 -^ 1,4 tan/h tiiy thudc vao dp dm ban dau cua h^t, dp am can thidt phai dao tren 22%, dioi gian dao... dd quy trinh cdng nghe the hien tren hinh Cac buoc cua quy trinh cdng nghe say hat cd giai doan u trung gian dugc tien hanh nhu sau: ] Chudn bl nguyen lieu: Can dugc say so bp den dp am khoang... Sdy giai dogn I thuc hien dm ciia hat tir 24% den 18% : Nhiet dp tac nhan say: ddi vdi thdc: 40°C; ddi vdi ngd: 40"C; ddi vdi dd tucmg: 38''''C Tdc dp giam am ciia giai doan khoang 0,6^ 1,0%/gid Giai