KHOA HOC CdNG N G H t
IXIGHIEIV C U U AIVH HUOIXIG C U A L U U LUOAIG KHOIVG K H i T d i CHAT LUQIVG SAIXI P H A M CHE DEIXI
O R T H O D O X (OTD) K H I LEIXI MEIXI TREIXI T H I E T B l LEIXI MEIXI LIEIXI T U C
Nguyen Duy IhjnhS Nguygn Vi^t Tin T6MTAT
San xudt che den OTD d Vidt Nam vdn ap dung phuong phip l^n men gian doan bdng khay nhua nen chat lupng san pham thirdng lliap va khdng dn dmh. Bai vi^t poi thieu kdt qua nghidn ciiu sif anh hudng cua luu lu^ng khong khi d^n chat luong san pham ch6 den Orthodox (OTD) khi Idn men trdn thi^t bi ldn men lien tiic. Ket qua nghifin ciiu da khSng dinh lim lupng khdng khi cd anh hudng rat 16n d^n thdi gian Idn men, thanh phan hoa hgc, chdt lupng cam quan va ndng sudt ciia thiet bi voi lini lupng 6.000 m^/h, Ifin men 150 phiit, thi him lupng tanin: 13,996, chat tan: 34,2%, chdt lupng: 11,0 diem, nang suat thiet bi: 10,2 tan che tuoi/ngay. Vdi Iuu lupng 10.000 mVh, len men 120 phiit. dli ham luong tanin: 13,2%, chdt tan: 34.6%. cMt luong: 11.3 diem, nang suat thiet bi: 12.7 tan che tuoi/ngay. Voi luu luong 12.000 mVh, len men 90 phiit, thi ham luong tanin: 15,4%, chat tan: 35.5%, chdt lugng: 11,4 di^m, nang sudt thi^t bj: 16,9 tdn chfi tuoi/ng^y.
Tikhda; San xudt chi den OTD, cong nghSva thidt bilSn men, thidt bi iSn men ken tuc, lin men gian doan.
anh hadng cua luu lugng khong khi
?i
1 . BAT VAN BE
Trong day ehuyen san xudt ehd den OTD, sau khi vd (qua trinh pha vo t^ bdo vd dinh hinh), la ehe dupc dua dl len men. Dliy la mdt giai doan edng nghd rat quan trong ed vai Ird hoan thidn chdt luong eho chd den vd cde ehi tidu mui, vi vd mau sde cua san phdm [1, 2]. De thuc hidn qua trinh ldn men, du an
"Hoan thiin cdng nghi va thidt bi lin men hin tuc chi den OTD cdng suat 16 tdn chi bup tuoi/ngif da thiet ke va che tao thanh edng thiet hi ldn men lidn tuc va da dua vao san xudt thii nghiem dl thay the qud hinh len men gian doan tren khay dang dupc su dung phd bien hidn nay. Trong qua trinh ldn men ehe, vide eung cap day dii oxy dupe eoi la ydu td quan trpng nhat dd dam bdo ehdt lupng che san phdm [1, 3, 5]. Giai phdp hdn tuc thdi khdng khi am xuydn qua ldp che dupc rai deu trdn bang tdi ludi da dupc thue hien ddi vdi thiet bi ldn men. Thue chat day la qud trinh cung cdp oxy tir khdng khi de ehuyen hda cde ehdt trong la ehe nham hinh thdnh cdc tinh chat dae trung cho che den. Ddng khdng khi dm mat thdi qua ldp che cdn ed vai trd lam giam nhidt dd, ddng thdi giu nhidt do vd dp am cua khdi ehe dn dinh trong sudt qua hinh len men [3, 4, 5].
Viec eung cap oxy la ydu td rat quan trong anh
Trucmg Dai hgc Bdch khoa Ha Ngi
hudng den chat lupng cua ehe san pham, vi di^ da tien hdnh "Nghiin ciiu anh huong cua luu lu^g khong khi tdi chat lugng sin pham che den Orthodox (OTD) khi lin men tiin tiiidt bi lin mea hin tuc". Ket qua nghidn cuu se Id co so- khoa hoc de tiep tuc hodn thidn thiet ke vd chl tao thiet bi len men lidn tue ehd den OTD, ttr dd cd the dua thi^tbj vdo ling dung mdt cdch hidu qua hon trdn cdc d^
chuyen san xudt ehd den OTD eua Vidt Nam.
2 . BM TUOK VA PHUONG PHAP (INHflBy CUu 2.1. Ddi tugng nghidn cihi
- That bi tiling dd nghiin cuu. Thilt bi ldn men Hdn tuc ehd den OTD - san pham cua Du dn san xuat thu nghiem cdp Nha nudc: "Hodn thidn cdng nghdva thilt bi lidn men Uen tuc che den OTD cdng suat 16 tdn che bup tuoi/ngdy". Thiet hi da dupe thiet kl va che tao thu nghidm hodn chmh va Mp dat tai xudng vd vd len men cua Cdng ty Cd phdn Che Sdng Lo Tuydn Quang.
- Nguyin hiu nghiin cuu. Su dung nguydn lieu ehe hroi hien dang cd d Cdng ty C6 phdn Che Song Ld. Tuy nhidn, trong qua trinh nghidn eiju, da lua chpn nguyen lieu theo tidu chi: ehe tuoi khdng bj oi ngdt, hu hdng. Ty Id la gia banh te khdng ldn hon 50% theo khdi lupng (xdp xi loai D theo TCVN). Khoi luong chd tuoi diing trong mdi ldn thi nghiem tir 800
62
1 ^
NONG NGHllP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011KHOA HOC C 6 N G NGHfi
den 1000 kg de phu hop vdi nang sudt ciia thilt bi len men.
- Sdlan lip lar. Thi nghiem dupc lap lai 3 ldn vdo 3 thdi dilm khde nhau: cudi thdng 5 (ddu vu ehd), eudi thdng 7 (giiia vu che) vd cudi thdng 9 (cudi vu che). Cac sd Ueu dupc trinh bay trong cac bang Id gid tri trung binh ciia cdc ldn thi nghidm.
Cde thi nghidm dupc tiln hdnh bat ddu vao liic 12 gid, vdo thdi dilm nay mdi trudng thirdng cd nhiet dd cao nhdt Vdo ddm hdm trudc vd sang hdm sau, cdc cdng doan heo va vd dirpc thuc hien de chudn hi sdn sang nguyen Ueu eho nghien cuu qua trinh len men vao liic 12 gid. Budi chilu, thuc hidn cdng doan say de thu dupc che khd ban thdnh phdm Id kdt qua nghidn cuu.
- Dia didm nghiin cihr. Dupc tiln hdnh t?i phan xudng vd - len men trong nhd may chd den OTD cua Cdng ty Cd phan Che Sdng Ld Tuyen Quang.
- Thdi gian nghiin cdu. Dupc thuc hidn vao vu che nam 2014 (tir thdng 5 ddn thang 10 nam 2014).
2.2. Phuong phdp nghidn cuu
2.2.1. Phuong phip tiiidt lip chd dd ky thuat trong qui trinh lin men che trin thidt bi lin men hin tuc
2.2.1.1. Tao radddm cua chd lin men Nguydn Udu che tuoi dupc lam heo din dp am 65% bdng cdch heo ehe trong thdi gian tu 6 ddn 8 gid [1, 5]. Quy trinh heo ehe dupc tien hanh hodn todn theo quy dinh eua Cdng ty Cd phdn Che Sdng Ld.
Khi che da heo dupc 6 gid, cb sau mdi 15 phiit, tien hanh phan tieh dp am cua nguydn Udu mpt ldn de
dimg qua dinh heo khi che dat dd am 65% nhu da du dmh.
2.2.1.2. Tao do am cua khdng khi
Thi nghidm d muc dd am khdng khi tir 95% den 97% [3,4]. De cd dp am ndy, can tidn hanh dieu chinh lupng nudc phun vdo may phun am, dimg mdy do dp am d l dilu ehinh luong nudc phun cho den khi dp am khdng khi dat trong miln tir 95% ddn 97% nhu mong mudn.
2.2.1.3. T$o nhiet do cua khong khi Nhidt dp cua khdng khi am thdi vdo thiet bi ldn men phu thude vdo nhidt dp cua mdi trudng trong nhiing ngay thi nghiem vd phu thude muc dp ldm am khdng khi bang each phun nudc nhd may phun am.
Trong trudng hpp nghidn cuu ve lim lupng khdng khi vdi dp am trong miln 95% - 97%, nhidt dp cua khdng khi chi edn phu thude vdo nhidt dp ciia mdi trudng. Trong qud trinh tiln hdnh thi nghidm do dp am cua khdng khi eimg liie do nhidt dd mdi trudng (dung eu do cd chiic nang do dtrpc ea 2 thdng sd nay).
2.2.1.4. Be day cua lap chi tiin bang tii lin men Bdng cdeh dieu ehinh gudng gat trdn bang tai tilp Udu de tao ra be ddy ldp che trdn bang tai ldn men. Cae thi nghiem deu dtroc thiic hien vdi b l day ldp ehe 15 em [1, 5], tuong ling vdi mat dp che trdn bang tdi Id 61,2 kg/m^. Vdi b l day nay, thiet bi ed the dat dupc nang sudt tuong iing Id 16.926 kg chd tuoi/ngay, phu hgp vdi nang sudt thiet ke 16 tan ehe tuoi/ngay.
Oph 30 pb
Ddu bang tai
O"
60 ph 90 ph j 120 ph 150 ph
••o....
Cudi being t ^Hinh 1. So d6vi trilby miu n g h i ^ cihi trgn bang tai 16n men theo thdi gian 2.2.1.5. Thoi gian len men
De xac dinh thoi gian, theo chieu doc cua bang tai ten men dinh ra 6 vi tri la A, B, C, D, E, G bang each dat ch^ do chuydn dpng cua bang tai o muc toi da la 150 phiit Cac thdi di^m 16n men 0 phiit (vi tri
A), 30 phiit (vi tri B), 60 phiit (vi tri C), 90 phiit (vi tri D), 120 phiit (vi tri E), 150 phut (vi tri G) (theo so do hinhl).
-Lay miu theo thai gian, xulyva bao quan miu nghien cmr. l i y mlu nghien ciiu theo theo thoi gian
KHOA HOC CONQ NOHj lln men 0, 30, 60, 90,120 vd 150 phiit, tuong img vdi
cac vi tri da dinh. Tai mdi vi tri ndu trdn, cdn Idy 3 mdu ban ddu theo chilu ngang cua bang tai ldn men vdi khdi lupng tdng edng 1500 gam, trdn dlu va lay 500 gam dua di sdy khd din dp dm 3% - 5%, bao qudn can than trong tail chdt deo, hiit ehdn khdng vd ban kin, de dua di phan tieh thdnh phdn hda hoc vd cam quan.
2.2.2. Phuang phap tiii nghiim ddi chung: lin men giin doan tiin khay
Thi nghidm len men gian doan trdn khay dupc tiln hanh song song vdi muc dieh so sanh giCta ldn men truyin thdng gidn doan trdn khay vdi len men Udn tuc trdn thiet hi ciia du an.
Sau khi vd va lam toi, che dupc dua vao ldn men trdn thilt bi Hen tuc va ciing lay ngay chd nay eho vdo 6 khay nhua dl len men gidn doan. Khdi lupng che ldn men trong 1 khay Id 10 kg vdi b l ddy ldp chl trong khay khoang 10 cm [1, 2, 3, 4, 5]. Vdi lupng che trong mdi khay nhu da neu, dupc coi la each len men tdt nhat khi ling dung len men gian doan trdn khay a cac nha may san xuat che den OTD hidn nay.
Ca 6 khay dupe dat trdn 1 gid bdng thep vd dat trong khoang khdng gian trong phdng vd - ldn men.
Khdng khi trong phdng cd do am tii 95% ddn 97%.
Cae khay dupc ma sd theo A, B, C, D, E, G tuong ling vdi cdc thdi dilm len men 0 phiit (khay A), 30 phiit (khay B), 60 phiit (khay C), 90 phut (khay D),
120 phiit (khay E) va 150 phut Odiay G). Mdi khaylj 1 dilm Idy mlu nghidn ciiu theo thdi gian ldn men.
Khi hit thdi gian da dinh, lay todn bd khdi che Irotig khay, trdn deu vd lay mdu che vdi khdi lupng 500 gam, dua di sdy khd va bao quan gidng nhu da Idm vdi mdu che lay tren bang tai ldn men.
2.2.3. Phuang phap tao luu lugng khdng kbi khac nhau tiong qui trinh lin men
Khi xoay vi tri tdm ehdn d^t trdn dng trung tam, luu lupng khdng khi frong dng hung tam se thay ddi Bang cdch ndy, tao ra 4 luu lupng tuong ung: 6.000, 8.000,10.000 va 12.000 mVh.
2.2.3.1. Tinh toin luu lugng dong khi Su dung phuong phap do tdc dp trung binh tai tiet didn ciia dng trung tam d l xac dmh luu lupng khdng khi [5]. Tir tdc dd trung binh, tinh luu lupng khdng khi theo edng thiie (1):
I Q ^ 3600.V.F (mVh)| (1)
Trong dd: Q: The tieh khdng khi di qua tilt difin cua dng hung tam (mVh). 3600: Ddi tdc dd khdng khi ra m/h. v: Tdc do trung binh cua khdng khi di qua tilt didn (m/s). F: Dien tich tilt dien ciia di^
tmng tam khdng khi di qua (m^.
2.2.3.2. Dung cu do tdc do dong khi Su dung mdy do tdc dd va nhiet dp cam tay hien sd dl do tdc dp ddng khi.
D ^ tinh k;^ &uat ctia may do tdc dO vd nhidt dd Ky hieu mdy:
Nudc san xudt:
Chiie nang:
8A-15TVotec Cdng hda Lien bang Diie Do tde dd vd nhidt dd ddng khi Do tdc do chuyin ddng ciia ddng khi
- Pham vi do tdc do:
- Vaeh ehia tde dd:
1-30 m/s 0,01 m / s Do nhidt dd ciia khdng khi
- Pham vi do nhidt dd:
- Vach ehia nhiet do:
Kieh thude mdy (khdng ke phan dau do):
Khdi luong:
Ngudn dien:
-loocdln + ao^c
0,1"C 130 X 40 X 25 mm
100 g 9VIEC6LK61
Cich do: Keo thdng can ndi sensor vd dua ddu ^'^^ ^ ^ ^ t^'^ "^d va nhidt dd cda khdng khi. Ghi cdm biln din vi tri can do. Bam cac phim tren than ''^^ ^ ^^•
may d l do va doe cae tri sd edn do. Trdn man hinh 2.2.3.3. Tiin hanh do luu luvng khong khi '
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1 /20U
KHOA HOC CdNG NGHl Do luu lupng khdng khi iing vdi b l day ldp che
len men trdn bang tai Id 15 cm. Khi do luu lupng, cac tdm ehdn d$t trdn 2 dng din nhdnh vd trdn 6 dng phdn phdt khi vdo timg modul dlu dupc md tdi da d l gidm din miic thdp nhdt trd luc trdn dudng dng. Tien hdnh do luu lupng ngay tai vi tri ndi giua quat ly tam vd dng trung tam.
2.2.3.4. Phuong phip do luu liwng khong khi tiin dng trung tam
Ong dan trung tam cd tilt didn hinh chii nh^it, vl thd luu lupng khdng khi di qua dng ddn dirpc tinh theo cdng thiic 2:
Vi trf 1 vd 2 TdcddN tdm dng j
I Q = 36Q0.v.a.bmVh | (2) Trong dd: Q: Luu lupng khdng khi di qua dng (m^/h). 3600 sd ddi tde dp khdng khi tu m/s thanh m/h. Tri sd tdc dd trung binh ciia ddng khi di qua dng (m/s). a vd b: kich thude bdn trong cua tilt didn dng (m) (a.fa = F trong cdng thiie 1).
Ddng khi ehuyen dpng qua dng cd tdc dp khdng ddng nhat Tax tam dng, tde dd ldn nhdt va tai cgnh dng, tdc dd gan nhu bang khdng (xem hinh 1).
Hinh 1. Sff dd phdn bd ddng khi trong tilt didn dng ddn vd vi tri do tdc do trdn tilt di|n Vide xdc dinh tr? sd tdc dd trung binh tren tilt
didn theo mat cong parabol la rat khd khan, 6.i don gian phdp do, cdn tiln hanh do tai 5 vi tri (1, 2, 3, 4, 5) theo dudng chdo cua tilt dien. Dl lam dupc dilu ndy, phdi tao mdt eiia nhd hinh vudng ed nap tren thdnh dng &% dua ddu do vdo bin trong dng. Vi tri dat ddu do dupc xac dinh bdng cdch dilu chinh edn do cua may do. Tdc dd ciia ddng khi tgi tilt didn Id
trung binh cdng cua 5 gia tri do dupc d 5 vi tri vd tinh theo cdng thiic (3):
EZ^
'l+p2+r3+r4+i;5 (3) Bdng each tinh todn, da tinh dupe 4 luu lupng khdng khi tirong iing vdi 4 toe dd trung binh cua ddng khi trong dng trung tam nhu sau:Luu luong kh6ng khi (mVh) Toe do trung binh ciia kh6ng khi (m/s)
6.000 8,3
8.000 11,1
10.000 13,8
12.000 16,7 Dilu chinh luu lugng cua khdng khi thdi xuydn
qua ldp che bdng edch xoay vi tri tam ehdn trdn dng trung tam din khi dat dupc tdc dp trung binh tren tilt didn tuong iing vdi bang sd dr trdn. Ddnh dau cde vi tri ciia tay quay dilu chinh Iuu lupng tuong iing vdi tde dp de eho nhiing thi nghiem ldn sau.
2.24. Phuong phap phan tich hda hgc 2.2.4.1. Cic chi sd hda hgc cin xac dinh Dp am; hdm lupng tanin; ham lupng ehat hda tan.
2.2.4.2. Phuong phap phin tich
Cac phan tich hda hpe dupc tien hdnh tai phdng thi nghidm ciia Vidn Kilm nghidm An todn Vd sinh
Thuc pham Qude gia, Bd Y t l va Phdng Kiem tra Chdt luong San pham QCCS) eua Cdng ty Cd phdn Che Sdng Ld.
TT 1 2 3
T«n chiaeu Do am ciia che Ham luong chat hoa tan
Ham luong tanin
Phuong phap xac dinh TCVN 5613-1991 TCVN 5610-2007 TCVN 9745-2013 Cdc phep phan tich duoc lap lai it nhat 3 Idn va tinh tri sd trung bmh cdng. Nhung kit qua phSn tich vupt qud 0,2% gid tri trung binh se hi loai [1].
2.2.5. Phuong phap phin tich cam quan De ddnh gia chat lupng cua san pham che, dp dung phuong phdp cam quan theo TCVN 3218-1993.
KHOA HOC CdNG NGHi
Phan lich duoc thuc hien tai phong Ky thuat va Chat De thay ro anh huong ciia lini lu<?ng khong khi, luong San phSm cua Tong Cong ty Che Vi4t Nam. da tinh toan ii dua v4 cich tinh theo chi phi the ticli S KFT flIU VA HUD LUJiN khong khi am cho 1 don vi khoi luong che Ifin men
trong 1 don vi thin gian. Dai lirong nay cho bi^t ra 3.1. Anh huong cila luu lupng khang khi iin m ^ ^ j ^ ^ ^ ^ ^^^^ y^. ^ ^^ ^^^ ^lj„ ^ ^ ,^^ ^^
b i & ddi ham lupng tanin v4 chit hda tan trong ch« ^^^ ^ ^^ j „ ^ ( ^ ^ ^^^ ^ bang 1!
theo thdi gian len men tr6n thi^t hi
Bang 1. Thd tich kh6ng khi Im chi phi cho 1 don vi khdi lupng c h i l«n men
Be day (cm)
15 Thm gian len
men (phiit)
60 90 120 150
Nang suat thiet hi tinh theo che len men
(kg/h)
1300,5 867,0 650,3 520,2
Che blip tuoi a/ngay)
25,4 ' " " l 6 ^ '
12,7 10,2
Chi phi khong khi am cho 1 kg che len men trong 1 giir m= KK/kg che/h
tTng voi luu luong 6.000 mVh
4,61 6,92 9,22 11,53
Ung voi luuluong 8.000 mVh
6,15 9,23 12,3 15,38
Ung voi luu lirpng laOOOmVh
7,69 11,53 15,38 19,22
Ung voi luu lupng 12.000 m ' A
9,23 13,84 4 18,45 23,07 Nh§n xdt Tu sd lidu d bang 1 thdy rdng: iing vdi
b l ddy ldp chd ldn men trdn bang tdi Id 15 cm, khi thdi gian ldn men tang ldn, nang sudt eua thiet bi gidm di. Vdi thdi gian ldn men 60 phut, nang sudt thiet bi la 1300 kg che len men/h, tuong duong 25,4 tan chd tuoi/ngay: khi thdi gian ldn men Id 150 phiit, nang suat chi cdn 520 kg chd ldn men/h, iing vdi 10,2 tan ehe tuoi/ngay. B6 dam bao nang sudt theo yen cau thiet ke (16 tdn ehe tuoi/ngdy), thdi gian ldn men sd phai la 90 phiit Ung vdi thdi gian ldn men 90 Bdng 2. Sg tiiay ddi hdm luong tanin trong chd phil
phiit, khi luu luong khdng khi thay dli, chi i khdng khi am cho 1 kg che ldn men trong 1 gid thay ddi tir 6,92 m^ den 13,84 m^
Cdc thi nghiem nghidn ciiu dnh hudng ciia luu lupng khdng khi din su bidn ddi hdm lupng tanin vi chat hda tan trong che theo thdi gian ldn men duoc thue hidn nhilu lan vd sd hdu thu dupc Id gia fri trung binh cua cde ldn thi nghiem. Cde kit qua phan tich dupc trinh bay b ede bang 2 va 3.
thupc vdo Imi lupng khdng Mii vd thdi gian ldn men
TT
1 2 3 4
Luu lupng khdng khi (mVh)
6.000 8.000 10.000 12.000
Diem A Ophut 30,6 30,6 30,6 30.6
Thtri gian len DiemB 30 phiit 25,8 25,1 24,4 23,8
men (phiit) va DiemC 60 phiit 19,2 18,5 17,2 17,2
ham luong tanin (% chat kho) BiimD
90 phiit
• 17,4 16,8 16,1 . • a S A - ^ i
DiemE 120 phiit 14,5 13,8 13,2 12,5
D i t o G 150 phiit
13,9 13,2 12,6 11,9 Nhan xdt:
Tu cdc sd lidu trong bang 2 ed thi di den nhan xet nhu sau: trong qua trinh ldn men vdi luu lupng khdng khi khae nhau, ham lupng tanm dlu lien tuc giam di theo thdi gian ldn men. Luu lupng khdng khi cang thap thi miic dp gidm tanin cang eham. Dilu nay cd thi duoc giai thich nhu sau: khi luu luong
khdng khi tang len thi lupng oxy cung cap eho qua trinh oxy hda tanm trong ehe de hinh thdnh cac cMt dac tnmg cho ehe den tang Idn, lam cho ham luong tanin trong che giam di. Thi du: khi thdi gian l&i men 90 phiit vdi luu lupng 6.000 m^/h, ham lupng tanin trong ehe cdn lai 17,4%, nhung khi luu lirpng cr mucl2.000 mVh thi ham luong tanin la 15,4%.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1 /2016
TT 1 2 3 4
KHOA HOC CONG N SHE
Bdng 3. Si^ thay ddi hdm lucmg chdt hda tan trong chd phu thuOc vdo Imi luoroff khdng khi vd thdi gian lln men Lim lupng
khdng khi (m^/h)
6.000 8.000 10.000 12.000
Thdi gian len men (phiit) va ham lupng chat tan (% ehdt khd) Diem A
0 phiit 40,2 40,2 40,2 40,2
DilmB 30 phiit 39,7 39,5 39,2 39,1
DilmC 60 phiit 38,8 38,3 37,9 37,3
DilmD 90 phiit 37,8 37,4 36,9
1 '• . 3 & ^ _; •'.'
DiemE 120 phiit 35,4 35,0 34,6 34,2
DilmG 150 phut 34,2 33,8 33,4 33,1 Nhin x^tTii cdc sd heu trong bang 3 thdy rang
trong qud trinh ldn men vdi luu luong khdng khi tang len, theo thdi gian len men, ham lirpng chat hda tan Hdn tuc gidm nhimg miic giam khdng nhilu. O ea 4 trudng hpp, lupng chat tan trong che chi giam tir 6%
den 7%. Luu lupng khdng khi cao thi miic dp gidm ehat hda tan ed phan ldn hon. Dieu nay ed thd dupc giai thich nhu sau: khi luu luong khdng khi tang len, lupng oxy cung cdp eho qua trinh oxy hda tanin trong che tang ldn lam giam ham lupng tanin keo theo su giam chat hda tan.
3.2. Anh huong cua luu lugng khdng kia. din su biln ddi chdt lupng cam quan ciia chd theo thdi gian ldn men trdn thilt hi
Che dupe len men hdn tuc trdn thilt bi vdi dilu kidn ky thuat: khdng khi dupc lam dm din dd dm trong khoang 95 - 97%, nhiet dp khong khi biln ddi trong mien tir 27 den 30,7°C (day la miln nhidt dp thieh hpp), thdi gian ldn men tir 0 phiit den 150 phiit vdi be day eiia ldp ehd tren bang tai len men 15 em.
Thi nghidm dupc tien hanh nhilu lan va lay mdu de thu nem danh gid chdt lupng cam quan cua che ve miii, vi va trang thai cua nudc chd theo thdi gian ldn men. Sd heu thu duoc la tri sd dilm trung binh cua cde lan thu nem vd dupc trinh bay d bang 4.
Nh$n xdt Tir sd hdu trong bang 4 thdy rang:
chat lupng eua chd tang dan theo thdi gian len men nhung vdi mdi luu lugng khdng khi khdc nhau, su
- Vdi luu luong 6.000 mVh vd 8.000 mVh, ehdt luong cam quan tang lidn tue eho den tan thdi diem 150 phiit, chat lupng gan nhu dat gia tn ldn nhdt nhung ehua khang dinh da dat tri sd cue dai hay khdng vi thdi gian ldn men 150 phiit la qua ddi vd nang sudt thiet hi chi d miic rdt thap (10,2 tan ehd tuoi/ngdy), trong khi diem danh gid ehat lugng eung ehi a miic 11,0 dilm vd 11,2 dilm.
- Vdi luu lupng 10.000 m^/h chat lupng che tang dan vd dat tri sd cue dai 11,3 dilm a thdi dilm 120 phiit ldn men, sau do chat lupng san phdm cd xu hudng gidm, nang sudt thilt bi d miic 12,7 tan che tuoi/ngdy.
- Vol luu lirpng 12.000 m^/h, diem chat lupng ehe tang dan vd dat tri sd cue dai 11,4 d thdi dilm 90 phut ldn men, sau dd chat lupng sdn pham ed xu hudng giam ddn, nang suat thiet bi d miic 16,9 tan ehe tuoi/ngdy, d^t nang sudt thilt ke.
Tu nhiing nhan xdt trdn cd thi thdy rang:
+ Luu lupng khdng khi am thdi vdo dult bi ldn men ed anh hudng rat ldn din chat lugng dia che;
khi luu luong tang len, ehe cd chat lupng tdt hon.
+ Luu lupng khdng khi am thdi vdo thilt bi ldn men cdn ed anh hirdng tdi thdi gian len men. Lmi lugng cang ldn, thdi gian ldn men eang giam.
+ Thilt hi ldn men ldm vide tdt nhat vdi Iuu lupng khdng khi 12.000 m^/h iing vdi b l ddy ciia ldp ehd 15 cm vd thdi gian Ien men thieh hpp la 90 phiit thay ddi cd khac nhau:
Bang 4. Chdt lupng ciia chd biln ddng phu thuoc vdo Imi lupng khdng khi vd thdi gian ldn men TT
1 2 3 4
Luu luong khtogklii (mVh)
6000 8.000 10.000 12.000
Thoi gian len men (phiit) va diem thir nem DitoA
0 phiit 7,5 7,5 7,5 7,5
DiemB 30 phiit 9,2 9,5 9,8 10,1
DiemC 60 phiit 9,6 9,7 10,1 10,6
DiemD 90 phiit 10,2 10,3 10,8 11,4
(diem tdng hpp) DiemE 120 phut
10,8 10,9 11,3 11,2
DiemG 150 phiit 11,0 11,2 11,0 9,9
KHOA HQC CdNG NGHfi 3.3. Thi nghilm ddi chiiog: ldn men gidn dogn
t r d n k h ^
0 nhilu nhd may sdn xudt che den hidn nay vdn dung khay nhua dl len men che theo phuong phap gidn doan, vi thd nghien ciiu len men gidn doan che trdn khay dupc tiln hdnh song song vdi vide nghiin ciiu ldn men che tren thilt bi lien tuc de so sanh.
Phuong phdp ldm mlu nghien eiiu da duoc trinh bdy d muc 2.2.2.
Cac khay che dugc dat h-ong mdi tnrdng khdng khi ed dd dm 95% - 97% vdi nhiet dd tir 29''C din 31"C
vd dd dm ciia ehe Id 65%. Khdi lupng ehe trong 1 khay Id 10 kg, bd day ldp chd trdn khay khodng |3 cm.
3.3.1. Chat lugng cim quan cua che tiong qua tiinh lin men giin dom titn khay theo thai gian
Kit qua ddnh gid ehdt lupng cam quan cac mlu che san phdm duge ldn men gidn dogn tren khay Id tri sd dilm trung bmh cda eac lan thi nghiem dugc trinh bay d bang 5.
Bdne 5. Su b i ^ d6i c h ^ luong TT
1
Do am ban ddu ciia che (%)
65
cam quan d^E che khi len men gi4n doan tren khay theo thiM gian Thoi rian Ito men (ohlit) va &\im thir n^m (diim tong hpp) | Khay A
0 phiit 7,5
KhayB 30 phiit 8,0
KhayC 60 phut 8,7
KhayD 90 phiit 9,4
i*KhS."S"-*
120 phiit 9.6 . j ^
KhayG 150 phiit
8,5 1 Nh$n xet Khi ldn men trdn khay vdd dp am mdi
trudng 95% - 97% vd dd am ban ddu cua ehd Id 65% thi dilm ehdt lugng tdng hpp eao nhat 9,6 tai thdi dilm 120 phiit, thdi dilm dugc coi id kit thue qud trinh ldn men trdn khay.
3.3.2. Bidn ddi thinh phan hda hoc cua chd trong qua trinh lin men giin doan tiin khay theo thdi gian
Ket qua phan tieh thdnh phan hda bpc co ban cua che khi ldn men gian doan trdn khay theo thoi gian dupc trinh bay trong bang 6.
Nbin jTi^tTrong qua trinh ldn men gidn doan trdn khay, hdm lugng tanin vd chat hda tan dlu giam.
Tai thdi dilm 120 phut, qua trinh ldn men kit diiic, ham luong tanm cdn lai 12,1% vd hdm luong chdt hoa tan cdn lai 33,6%.
B ^ 6. Su biin ddi thfinh p h ^ h6a hpe ca ban TT
1 2
Thanh phdn Tanin Chat boa tan
cira che khi len men gidn doan trgn khay theo thin gian Thiri gian len men (phut) vk ham luong tanin va chdt tan (%) Khay A
0 phiit 30,6 40,2
KhayB 30 phiit 25,6 38,6
KhayC 60 phut 20,2 36,8
KhayD 90 phiit 14,5 35,1
• ' K h a y E " ^ KhayG 120 phiit 1 150 phiit
12,1 33,6 .J
11,2 32,7 3.4. So sdnh chdt lupng cdm quan ciia chd trong Dl thay rd hon uu diem eiia phuong p h ^ ldn men qud trinh ldn men gidn dogn trdn khay vd ldn men lien tue bang thilt hi va ldn men gidn doan bdng khay, lidn tuc trdn thilt hi cdn tiln hdnh so sdnh cdc mdu ehe thi nghiem cd chat
lugng tdt nhdt; kit qua dupc trinh bay d bang 7.
Bang 7. So sdnh chdt lugng ciia chd khi ldn men gidn dogn Irdn khay vd Idn men lidn tuc trdn thilt bj theo thdi gian
TT 1 2
Phuong phap len men Gian doan tren khay u e n tuc vol b i ddy 15 cm
Diem cam quan theo thin gian len men (phiit) 0
7,5 7,5
30 8,0
60 8,7
90 9,4 10,1 i 10,6 r 11,4
120 J 150 9,6 • 8,5 11,2 1 9,9 NhSn xit Til sd lieu b bang 7 co thi nhan xet * ^ ' ^^"^ •^""8 sang; vi chat nhat; c6 mui thom cd?
nhu sau: chi den nhimg 16 miu va vi chua.
- Khi len men gian doan b-en khay vol thiri gian " Khi ten men lien tuc trCn thiit hi voi b i ddy IS thich hpp la 120 phiit diim ting hpp chdt lupng cua '="'• * * ' 8 ™ 1 ^ " e n thich hop la 90 phiit, diim chS che dat tuong irng la 9,6. Niroc che co mau nau do ^1^ tong hpp cua che dat cao hon khi ten men gian 68 NONG NGHIEP VA PHAT TRIEN NONG T H 6 N - KY I - THANG l/20l|
KHOA HOC C 6 N G N G H |
doan trdn khay vd tuong iing la 11,4. Nudc che ed mdu dd nau, trong sdng; vi chdt dgm diu; miii thom chd den dae trung, dd chiu, khdng cd mui ehua.
- Theo tri sd dilm cam quan, phuong phap ldn men Udn tue trdn may tdt hem nhilu so vdi phuang phdp len men gidn doan tren khay, thdi gian de dat chat lugng tdt nhdt Id 90 phiit, nit ngdn dupe 30 phiit so vdi len men gidn doan trdn khay (120 phut).
3.5. So sdnh tihdnh phdn hda hgc ca bdn ciia chd trong qud trinh ldn men gidn dogn trdn khay vd ldn m « i lidn ti;c trfin thilt b}
Tiln hanh so sdnh thdnh phdn hda hoc ca ban (ham lupng tanin, ham lupng ehdt hda tan) eua cdc mdu ehe san pham dupc ldn men bdng hai phuong phap: ldn men gian doan trdn khay va ldn men lidn tuc trdn thiet hi vdi b l day ldp ehe trdn bang tai len men Id 15 em d* chl dd ky thuat dp dm ban ddu cua ehe khi ldn men deu Id 65%, dp dm eua khdng khi Id 95% - 97%, luu lupng khdng khi dm 12.000 m^/h. Kit qua phSn tich la sd lidu trung binh cua cdc Ian thi nghidm dugc trinh bdy trong bang 8.
Bdng 8. So sdnh st; biln thidn thdnh phdn hda hpe ciia chd khi ldn men gidn dogn trin khay vd ldn men ldn tuc trdn thilt bj theo tiidi gian
TT
1 2 3 4 5 6
Then gian lin men (phiit) 0 30 60 90 120 150
Ham lupng chdt tan (%
chdt kho) Trin khay 40,2 38,6 36,8 35,1 33,6 32,7
Tren thiit bi 40,2 39,1 37,3
'ii,5
34,2 33,1
Trin khay 30,6 25,6 20,2 14,5 12.1 ft 11,2
lupng (J6 chat
Tren thiit bi 30,6 23,8 17,2 l5,4 12,5 11,9 Nh^ xdt Tir kit qua b bang 8 ed the di den nhgn xet nhu sau:
- Trong qua trinh Idn men, ham lupng chat hda tan vd ham lugng tanin lien tye gidm theo thdi gian.
Khi ldn men Uen tue trdn may, miic dp giam chdm hon, trong khi dd nlu lln men gian doan tren khay thi miic dd giam nhanh hon.
- Khi kit thiic qud trinh Ien men, hdm lugng chdt hda tan va tanin trong che den OTD ldn men Udn tue cao hon nhilu so vdi khi Idn men gidn doan trdn khay, vi thi nudc chd cd vi dam diu hon. Khi ldn men trdn bang tdi, do duge cap oxy day dii nen tanin dugc
chuyen hda tdt hon vd tdn that chat hda tan it hon.
Dilu dd tao ra cdc chi tidu chat lugng cao hon, d$c biet ehd ldn men trdn thilt bi khdng h i cd miii la, chua thiu, thi hidn rd d* diem cam quan tdng hpp.
- Thdi gian len men gian doan tren khay thieh hop la 120 phut
- Vdi be ddy ldp ehe 15 em, thdi gian ldn men Udn tuc trdn thilt hi thich hgp la 90 phiit
- Chat lupng che den ldn men trdn may tdt hon len men trdn khay rat nhilu.
Sd Udu so sanh dupc trinh bay trong bang 9 chi rd hon tinh uu viet ciia qud trinh ldn men Udn tuc bdng thiet hi ciia du an.
Bdng 9, So sdnh thdnh phan hod hpe co bdn vd dilm chat lupng cua dik den ldn men frdn k h ^ vd
Phuong phap ten men
Tren may Trin khay Chenh lech:
Ham lirpng tanm (%chat
kho) 15,4 12,1 3,2
Ham Iirpng chat tan
(% chat khi) 36,5 33,6 2,9
Diem chat lupng ting hpp
11,4 9,6 1,9 Nhin xdt sd lidu d bang 9 da eho thdy ro tinh uu vidt eua thidt hi ldn men Udn tuc. Vdi thdi gian ldn men 90 phut va lim lugng khong khi thdi vdo thilt bi dat 12.000 m^/h (tuong iing vdi chi phi khdng khi dm Id 13,84 mVkg che/h), che den OTD dupc ldn men tren thiet bi hon hdn che len men gidn doan trdn khay ea ve tinh chdt hda hpe va tinh chat cdm quan eiia san pham.
4. KET LUAN
- Lmi lugng khdng khi am dnh hudng din sir biln ddi thdnh phdn hda hpe vd chdt lupng cam quan ciia che den san phdm. Luu lupng cdng cao, su biln ddi eac chat cang sau sac de tao ra day dii nhung tinh chat dac trung cho ehe den va san pham ed chat lugng tdt hon.
- Luu lugng khdng khi dm anh hudng tdi ihdi gian ldn men. Luu lupng cdng thdp, thdi gian ldn men cdng ddi. Dieu nay anh hirdng tdi nang sudt lam vide
KHOA HOC CONG NGHfi cua thilt bl, vi thi trong mpi trudng hop, phdi giam
trd luc d l dam bao khdng khi dm thdi vdo thilt bi cd luu lupng ldn nhdt
Vdi luu lupng 6.000 m^/h, len men 150 phiit, hdm lupng tanin: 13,9%, chat tan: 34,2%, chdt lupng:
11,0 dilm, nang sudt thilt bi: 10,2 tdn ehe tuoi/ngay.
Vdi luu lupng 10.000 mVh, len men 120 phiit, ham lupng tanm: 13,2%, chdt tan: 34,6%, chat lupng: 11,3 dilm, nang sudt thiet bi: 12,7 tan che tuoi/ngay. Vdi luu lupng 12.000 m^/h, len men 90 phut, hdm lupng tanin: 15,4%, chdt tan: 35,5%, chdt luong: 11,4 dilm, nang sudt thilt bi: 16,9 tan che tuoi/ngay.
- Trong qud trinh ldn men, ham lupng ede chat nhu tanin vd chdt hda tan giam dan theo thdi gian, mac du ham lugng cua chung hi gidm di nhung khi ldn men bang thilt bi ldn men Udn tue vin cao hon che ldn men gidn doan tren khay rdt nhilu. Khi ldn men trdn thilt hi, ham lugng tanin 15,4%, chat tan 36,5%, dilm chdt lirpng 11,4, cdn lln men trin khay cd cac gid tri tuong ting dlu thdp hon (12,1%, 33,6%, va 9,6). Dieu dd da khdng dinh che den OTD dupc len men tren thiet bi, sdn pham cd chdt lugng tdt
hon, nudc pha ed mau dd nau, huong vi dam da, miii thom hon han che ldn men gian doan tren khay.
TAIUEUIHAMKlUO
1. Ngd Hiiu Hgp (1984). ^(aasiijAcAe. Dai hpe Bach khoa Ha Ndi.
2. I. A. Khotrolava (1985). Ky tiiuit chd bidn chi. NXB Ndng nghidp, Hd Ndi.
3. Martin Obanda, P. Okinda Owuor and Richard Mang'oka (2001). Changes in the chemical and sensory quality parameters of black tea due to variations of fermentation time and temperature.
Food Chemistry, Volume (75). Issue 4, Pages 395- 404.
4. Thomas Muthumam and R. S. Senthil Kmaar (Available onUne 7 March 2006). Influence oi fermentation time on the development of compounds responsible for quahty in black tea Food Chemistry.
In Press, Corrected Proof.
5. H. H. llounauiBHJiH H M. A. EoKyHaaa. Ximusi u mexHOJioeus IOH. MocKBa 1989.
RESEARCH THE INFLUENCE OF AIR FLOWTO THE QUALITY OF PRODUCTS OF ORTHODOX BLACK TEA (OTD) WHEN THE FERMENTATION ON CONTINUOUS
FERMENTATION EQUIPMENT
Thinh Nguyen Duy, Tan Nguyen Viet Summary
Production of OTD black tea in Vietnam is stiU apply the method of fermentation interrupted in plastic trays should the quality of products is usually low and is unstable. Articles introduction the research results the influence of the air flow on the quali^ of orthodox black tea products (OTD) when fermented in the fermenter continuously. Research results has confirmed the air flow has a great influence to the tune of fermentation, chemical composition, sensory quality and productivity of the equipment With a flow of 6,000 mVh, fermented 150 minutes, tanmn content: 13.9%, the solute: 34.2%, quahty: 11.0 points, equipment productivity: 10.2 tons of fresh tea /day. With a flow of 10,000 mVh, fermented 120 minutes, tanmn content 13.2%, the solute: 34.6%, quality: 11.3 points, eqmpment productivity: 12.7 tons of fresh tea / day. With a flow of 12,000 m^/h, fermented 90 minutes, tannin content 115.4%, the solute: 34.6%, quality: 11.4 points, equipment productivity: 16.9 tons of fresh tea/day.
Key words: Production of black tea OTD, technology and equipment for fermentation, equipment for continuous fermentarion, fermentation interrupted, intiuence of air Sow.
Ngudi phdn bidn: TS. N g i ^ n Nang Nhugng Ngdy nhdn bdi: 01/9/2015
Ngdy thdng qua phdn biln: 01/10/2015 Ngdy duy§t dang: 7/10/2015
NONG NGHIEP VA PHAT TRIEN NONG T H 6 N - KY 1 - THANG 1/2016
