HEO CHE BAiVG IMAIXIG LLTOIXIG IVIAT T R O I
D6 Van Chuang' T O M T A T
Hien nay co nhieu phuong phap de heo che. Sir dung nang luong mat troi de heo che dugc cho la phuong phap tiet Idem va hieu qua kinh te. Xac dinh cac thong sd nhiet do, do am tuong ddi ciia khong khi va do doi cua anh sang mat troi bien thien trong ngay, trong thang va trong nam de lam co so cho viec nghien cuu heo che true tiep bang nang lugng mat troi. Viec xac dinh anh huong ciia thoi gian phoi den chat lugng la 'i.^'>"'' che, khi cho anh sang mat troi co do doi khac nhau chieu tmc tiep vao la che da xac lap dugc mdi quan he giua do dgi cua anh sang mat troi va thai gian phoi toi do chay tap ciia la che, tir do xac dinh dugc phuang trinh hoi qui thuc nghiem vi mdi quan he giua do doi cua anh sang mat tnVi va thoi g'an phoi den do chay tap cua la che. Qua dd thi co dang hypecbol, xac dinh dugc 3 viing anh sang: vimg anh sang co dp doi thap E < 40.000 lux, viing anh sang co dp doi triing binh 40.000 lux < E < 80.000 lux, viing anh sang co dp do!
.•: cao E > 80.000 lux. Thuc nghiem da cho thay a viing anh sang co dp doi thap co the heo che den dp am dat yeu cau, thai gian heo tii' 120- 210 phut, dao m 30 phut/Ian, ty le che heo dung dat 80- 85%. O viing anh sang CO dp dpi tmng binh chi nen heo 30- 75 phiit, dao m 10 phiit/lan, sau do ket hpp vol heo mang 6- 8 gio, thuy phan con lai 63- 64%. Viing anh sang c6 dp doi cao, khong nen heo che.
Tir khoa: Heo che, nang luang mat troi
I. DAT VAN DE
Trong san xuat che den, heo che la giai doan dau tien nhung quyet dinh den nhtrng giai doan tiep theo va tir dd quyet dinh nen chat lugng san pham. D l heo che ngudi ta co the ap diing phuong phap heo tu nhien va phuong phap heo nhdn tao. Phuong phap heo tu nhien hien nay ma tren t h i gidi hay sir dung dd la che dugc rai ra nong, phen, bat va d l trong nha thoang khi de heo. Viec sir dung true tiep nang lugng ciia anh sang mat trdi d l heo che mdi chi dp dung cho san xuat che 6 long nhu'Dai Loan, Trung Qudc.
O Viet Nam chua cd cong trinh nao nghien cim v l viec sir dung true tiip nang lugng mat troi de heo che, cung nhu d nudc ngoai viec sir dung nang lupng mat trdi d l heo c h i mdi chi dugc dp dung cho san xuat che 6 long.
Nam trong viing nhiet ddi cd nhiiu gid va ndng, hang nam dat nudc ta tiip nhdn mot ngudn nang lupng mat trdi rat ldn, dac biet tir thang 3 d i n thang 12 (vu c h i cua Viet Nam cung tir thang 3 d i n thang 12). Trong cong nghe c h i bien che den, nhiet nang diing cho giai doan heo c h i rat ldn, thudng chilm tir 40- 45% toan bp nhiet nang dimg cho tat ca qua trinh san xuat [3]. Cdu hdi dat ra la ngudn nang lupng gan nhu v6 tan nay cd t h i sir dung 1dm heo che hay khong? N i u cd thi sir dung nhu t h i nao? Hien nay nhiiu doanh nghiep dang phoi heo che mot cdeh tuy
tien, chinh vi vay chat lupng che heo rat kem, tir d(
lam cho chfit lupng san pham khong cao. Dl tai
"Nghien ciiu su dung true tiep nang luong mat troi trong qua trinh lam heo la che " da giup cho cac doanh nghiep van dung vdo viec phoi heo che mot each hpp ly nhdm dn dinh va ndng cao chat lugng che san pham, tilt kiem nang lugng vd giam thieu 6 n h i l m moi truong, phii hpp voi nhiing qui mo san xuat vira va nhd va phii hpp vdi nen kinh t l thi trudng ciia dat nude ta hien nay.
II. VAT LIEU VA PHUUNG PHAP NGHIEN CUU 1. Vat lieu nghien cuu
- Nguyen lieu che tuoi gidng Trung du loai B theo TCVN 2843-79 [1] d huyen Thanh Ba, tinh Phii Thp.
2. Phuang phap nghien eiru
- Xdc dinh dp am che tuoi bdng phuong phap say nhanh [4].
- Xac dinh ty le che heo dung bdng phuong phap cam quan [2].
- Do nhiet dp khong khi bdng nhiet k l bach
phdn. . • . , . , - Do dp am tuong ddi cua khong khi bdng am
nhiet ke tdc.
- Do dp dpi ciia anh sang mat troi bdng thiet bi ISO-TECH ILM-350 cua Dai Loan.
' TS. Trung tam CNSH va VSANTTP
Truong Dai hpc Kinh te - Ky thuat Cong nghiep
K H O A HOC CONG NGHE
Ba thong sd la nhiet dp, dp am tuong ddi ciia khong khi va do dpi cua anh sang mat troi dugc do theo chu ky nhu sau: Trong mot ngdy dem thi cir 2 gid do mot ldn; mdi thdng do 3 ldn vao cac ngay 10, 20 va 30 hang thdng sau dd lay sd lieu trung binh;
trong nam thi do tir thang 3 - 12.
III. KET QUA VA THAO LUAN
1 Xac dinh cac thong sd khi tupng
Viec xac dinh cdc thong sd khi tupng chii yeu nhu nhiet dp, dp am tirong ddi ciia khong khi, dp dpi cua dnh sang mat troi trong ngay la co sd cho viec sii dung chimg de phoi heo che.
Bang 1. Mot sd thong sd khi tupng viing che 'ITianh Ba - Phu Tlig (Sd lieu 2008) rhang
3 4 5 6 7 8 9 10 11 12 Thang
3 4 5 6 7 8 9 10 11 12 Thang
3 4 5 6 7 8 9 10 11 12
2 h 0 0 E (lux)
- - - - - - - - -
T<J"C) 18 22 25,5 28 29 27 25 24 22 16
cp (%) 96 94 92 88 89 94 95 94 95 95 lOhOO
41,4 42 49,7 89,0 95,4 44,1 90,0 55,7 30,5 10,5
24 25 30 37 37 34 36 29 25 22
90 87 86 81 80 83 72 73 80 78 18h00
0,45 0,92 1,14 4,3 4,0 2,1 6,3 0,01
- -
20 30 29 34 35 31 33 27 24,5 20
90 85 83 80 80 85 80 85 87 84
4 h 0 0 E (lux)
- - - - - - - - -
Tk.k C'C) 17 21 24 28 28 26 25,5 24 23,5 16,5
(P (%) 97 93 94 90 90 95 94 93 94 94 12hOO
60,8 65,7 75,5 107 115 111 120 89,5 60,5 30,0
25,5 29 33 40 38,5 37 38,5 30 27 24
87 82 80 75 76 80 64 62 70 72 20h00
_ - - - - - - - - -
19,5 27 27 30 31 29 28 26 23,5 19
91 86 85 85 84 87 87 89 91 88
6 h 0 0 E (lux)
0,4 0,55 0,86 10,5 12,5 L7 1,0 0,03
- -
Tu< C'C) 19 22 25 28,5 28,5 27 26 24 24 18
cp (%) 95 92 90 89 89 90 88 89 92 90 14h00
65,7 75 102 108 110 110 104 45.3 50,0 25,6
27,5 33 35 41 40 39 37 32 26 23
85 78 72 65 66 70 70 61 75 76 22h00
- - - - - - -
• •• . .
- -
19 26 2,65 2,95 30 2,85 27 25 23 17
93 90 87 87 86 90 91 92 94 92
8 h 0 0 E (lux)
17,2 20,2 34,7 82,0 95,0 18,0 76,8 28,7 10,2 4,2
T a C'C) 21,5
23 27 33 34 28 32 26 24,5 19
cp (%) 93 90 88 85 84 87 80 81 90 89 IShOO
34,6 40,2 44,6 64,0 62,2 55,6 44,0 30,8 15,6 3,2
27 32 34 39 39,5 37,5 36 31 25,5 21
86 80 79 75 74 78 73 72 76 78 24h00
- - - - - - - -
- •
1,85 24 26 29 29,5 28 26 24,5 22,5 16
95 92 90 86 87 92 94 93 94 94 Trong do 7/, /,.' Nhiet dp trung binh ciia khong khi fC), (p: Do am tuong ddi ciia khong khi (%), E: Do doi ciia anh Scing mat troi (1000 liLx).
Qua bang 1 ta thay, dp dpi cua anh sang mat trdi vd nhiet dd khong khi la hai dai lugng quan he ddng bien. Klii dp dpi tang thi nhiet dp khong khi cung tang. Diln biin dd dpi anh sdng mat trdi va nhiet dp khong khi trong ngay nhu sau:
- Thap nhat tir 6h 00 - 8h 00 va 16h 00 - 18h 00 - Trung binh tir 8h 00 - lOh 00 vd 14h 00 - 16h 00 - Cao nhat tir lOh 00 - 14h 00, dac biet tir 12h 00 - 14h 00.
Bang 2. He sd
Nhiet dp va dp am tuong ddi cua khdng khi co quan he nghich bien, khi nhiet dd tang thi dp am tuong ddi ciia khong khi giam. Diln biin dd am khong khi trong ngay va dem nhu sau:
- Cao nhat tir 20h 00 - 6h 00. Trung binh tir 6h 00 - lOh 00 vd 16h 00 - 20h 00. Thap nhat tir lOh 00 - 16h 00 va dac biet tir 12h 00 - 14h 00. Mdi quan he nay the hien qua he sd tuong quan (Bang 2).
tuang quan R, va R2 Thang
Rl
-R,
3 0,899 0,932
4 0,673 0,936
5 0,813 0,932
6 0,763 0,908
7 0,649 0,908
8 0,875 0,924
9 0,744 0,967
10 0,630 0,905
11 0,841 0,937
12 0,887 0,956 R,: La he sd tuong quan giua Tj.^. va E. R^: La he sd tuong quan giira T^.j,. va cp
Qua sd lieu bang 2 ta thay mdi quan he giiia dp dpi cua anh sang mat trdi va nhiet dp khong khi biin thien trong ngdy theo cac thang tuong ddi chat, dugc the hien qua he sd tuong quan Rj = 0,630 - 0,899, nguyen do vao dau budi sang khi dp dgi cua anh sang mat trdi tang nhanh nhung nhiet dp khong khi tang cham, con vdo cudi budi ehilu khi do dgi dnh sang mat troi giam manh nhung nhiet do khong khi chi giam tir tir. Dp dpi va nhiet dp khong khi diln biin theo thdng trong nam ciing khdc nhau, dat tri sd cao nhat tir thang 6 - 9.
Mdi quan he giira nhiet dp vd dp am tuong ddi cua khong khi rat chat, the hien qua he sd tuong quan R2 = -(0,905-0,967).
2. Xac dinh anh hudng ciia thdi gian phoi den chat lugng la che khi cho anh sang mat trdi cd dp dpi khac nhau chieu true tiep vao la che
Khi cho dnh sang mat trdi chiiu true tiep vao la chi niu anh sang cd dp dpi nhd, thi sau mdt khoang thdi gian nhat dinh nudc trong la che thodt di, la che mat luc truong, nhung dpt che vdn giii dugc mau xanh va do mIm deo tang len. Neu anh sang cd do dpi ldn ngoai viec la che bi mat nude cdn cd hien tupng pha va cau tmc te bdo la; tai nhiing diem nay nudc bi mat di nhanh chong va chuyen mau, dupc gpi la che bi tap hoac chay tap. Kit qua cua sir chay tap nay phu thuoc vao thcxi gian tiip xiic true tiep giiia la che voi anh sang mat trdi va dp dpi cua no.
Kit qua dugc the hien d' bang 3.
Bang 3. Mdi quan he giua do dgi ciia anh sang mat trdi va thdi gian phoi tdi do chay tap ciia la che X- D p dpi
(1000 lux) 35-44 45-54 55-64 65-74 75-84 85-94 95-104 105-115
132 105 55 55 30 21 17 11
167 112 70 40 25 24 15 8
Y (Thai gian 152
97 55 35 24 16 13 9
158 124 78 64 20 18 15 6
phoi lam chay tap la che, phiit) 174 136 147 162 126 85 106 125 79 70 65 85 52 51 47 56 20 27 19 31 17 20 18 16 16 14 17 18 10 10 9 8
168 88 65 40 26 20 12 7
176 96 73 35 25 17 19 9 Dl thay ro mdi quan he nay, theo Hd Duyen
Tu [5], da lap bang tuong quan. Ddi vdi dai lugng X, img vdi 8 khoang dp dpi (35 - 44, 45 - 54,..., 105-115), da lay 8 gia tri trung vj tuong iing la: 40, 50, 60, 70, 80, 90,100,110.
Ddi vdi dai lugng Y, dau tien can chia khoang thdi gian, mdi khoang hon kem nhau 10 phut, theo
thii tu tir ngdn den dai, cdc khoang dd la: (3-15, 16-25, ... , 176-185; tuong iing vdi cac khoang nay da cd cac gia tri trung vi la: 10, 20 180. Ghi sd lupng cac gia trj X-Y tuong img trong timg khoang, da cd bang 4 tuong quan:
Bang 4 cho thay, iing vdi mdi gia tri ciia X co mot gid tri X, tuong iing.
KHOA HOC CONG NGHE
Khoang thai gian (phiit) 176-185 166-175 156-165 146-155 136-145 126-135 116-125 106-115 96-105
86-95 76-85 66-75 56-65 46-55 36-45 26-35 16-25 6-15
X Y
180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 Y
B a n g 4. B a n g tuong quan ] 40
1 3 2 2 1 1
158 50
1 2 2 3 1 1
106 60
3 3 2 2
67
70
2 4 2 2
46 SC-Y
80
4 6
24
90
10
20
100
5 5 15
110
10 10 Ung vdi mdi gia tri ciia Y cd mot gia tri Y^j
I k I k Trong dd Y^j = Z mij Y, = — S m„ Y
m. 10
nghiem Cr2), phai can cii vao dudng hdi qui ky vpng thuc nghiem (Tl). Tren dd thi dudng hdi qui ky vpng du bdo dudng hdi qui thuc nghiem co dang Hypecbol vuong.
Gia tri m,j gpi la tan suat hay sd lan xuat hien su tap la che.
Qua sd lieu bang 4 ta thay niu anh sang cd dd dpi cao, thi thdi gian gay chay tap la che giam xudng khi cho la che tiip xiic true tiip vdi anh sang mat trdi. Dac biet luc dp dpi ciia anh sang mat trdi rat cao (110.000 lux), thi thdi gian gay chay tap chi co 10 phiit. Sd di nhu vay la vi khi dp dpi cua anh sang mat trdi tang len, ddn den cudng dp ciia cac chiim tia tii ngoai, hdng ngoai diu tang. Tia tir ngoai nhanh chdng pha va cau tnic tl bdo la, tia hdng ngoai sinh nang lupng lam giam dp am tuong ddi cua khong khi xudng tir dd lam tang qua trinh thoat am ciia la che, dac biet la nhiing phan la cd tl bao bi pha vo-, tir dd ddn den su chdy tdp cua la che. Bilu diln mdi quan he ndy dugc thi hien tren dd thi 1 thong qua sd lieu bang tuong quan X- Y (Bang 4).
Dudng ndi cac diem Xj - Y^, ggi la dudng hdi qui ky vpng thuc nghiem. Trong dd: Tl la dudng hdi qui ky vpng thuc nghiem. T2 la dudng hdi qui thuc nghiem. De xac dinh dang cua dudng hdi qui thuc
180 160 140 120 100 80 60 40 20
0 -L.-1. !.^
- ^ T 1 -•-T2
50 100
l)t> (loi iinh Sdng mHl Iriii IIOOO l.u\) 150
Do thi 1. Mdi quan he giiia dp dgi ciia anh sang mat trdi va thdi gian phoi tdi dp chay tap cua la che
Xet mo hinh y = — -i- b (1) .
De tuyln tinh hod can ddi biin va dat t = 1 Do vay phuong trinh (1) cd dang: y = a.t -i- b (2) Sau khi thuc hien cac budc tinh todn dl xdc dinh phuong trinh hdi qui vl mdi quan he giira dp dpi cua anh sang mat trdi vdi thdi gian den dp chay tap cua la
KHOA HOC CONG NGHE
I
che va ddi bien, se xac dinh duoc dang ciia phuong trinh hoi qui (2) la:
9380
y = 82,6 (3)
.V
Voi he sd tuong quan giua dp dpi va thoi gian la R = 0,976, ta thay chirng co tuong quan rat chat. Klii kiem tra tinh tuong thich ciia phuong trinh (3), ta thay d muc y nghla a= 5% phmmg trinh hdi qui (3) la phu hpp voi thuc nghiem vdi dieu kien ta xet la 40< x
< 110. Qua duong bieu diln Tl, T2 ciia dd thi 1 ta cd the chia ra 3 viing anh sang: Vung dnh sang mat troi cd dp dpi thap: E < 40.000 lux. Viing anh sdng mat trdi CO dp dpi trung binh: 40.000 lux < E < 80.000 lux.
Viing anh sang mat troi co do dpi cao: E > 80.000 lux.
3. Nghien eiru sir dung true tiep nang lugng mat trdi de heo che
a. Vimg anh sang mat troi co dp dpi thap
O vimg CO dp dpi thap, qua thuc t l khao sat thi nhiet dp khong khi dugc chia 1dm 2 khoang nhu sau:
Khoing CO nhiet dp khong khi20-29'C
Ung-vdi khoang nay, nd thudng d thoi diem tir 6h00 - lOhOO va 16h00 - 18h00 cua thdng 3, 4, 5 va thang 10, 11, 12. O diiu Iden nay do dp dpi ciia anh sang mat trdi yeu, nhiet dp khong khi thap, do vay de tang cuong qua trinh thoat am ciia Id che, ta nen phoi heo che d dp ddy 1 - 3 cm, sau 30 phut dao ru mot ldn. Cac chi dp ky thuat dugc the hien dbang 5.
Bang 5. Phoi heo che b 20 - 29°C trong 'viing anh sang cd do dpi thap
ndy do nhiet do khong khi tuong ddi cao, de qua trinh dao ru thao tac dugc d l dang, dam bao hieu qua kinh tl va san pham co chat lugng tdt, ta phoi heo che d dp day 4 - 6 cm, sau 30 phut lai dao ni mot ldn. Cac che dp Iw thuat dupc the hien dbang 6.
Bang 6. Phoi heo che d- 29 - 38°C trong viing anh
sang cd dp dpi thap
k
Nhiet dp phoi heo
C'C) 29 - 32 32-35 35-38
Thoi gian (phut) 180-210 150-180 120-1150
Dp am con lai (%) 65-66 65-66 65-66
Ty le che heo diing
(%) 83-85 83-85 80-85
Nhan xet trang thai la che Mau xanh,
m4m Mail xanh,
ni^m Mau xanh,
mem
Nhiet do phoi heo CO
20-23 23-26 26-29
Thoi gian phoi (phiiO 270 - 300 240-270 210-240
Do am con lai (%) 65-66 65-66 65-66
Ty le che heo diing
(%) 82-85 82-85 83-85
Nhan xet trang thai la
che Mau xanh,
mem Mau xanh,
mem Mau xanh,
m^m
Q diiu kien khi tupng nay, ta cd the phoi heo che din trang thai dpt che mIm deo, tuc la dp heo vat ly dat yeu cdu ma la che khong bi chay tap. Thdi gian phoi heo 210 - 300 phiit, dp am cua che heo cdn lai 65 - 66%, kit thiic qua trinh phoi hlo mau sdc la che van xanh, mIm mai, ty le chi heo diing 82 - 85%.
Klioang CO nhiet dp khong khi29 - 38'C
Klioang nhiet dp nay thudng b thdi diem tir 6h00 - 8h00 vd 16h00 - 18h00 cua thang 6 - 9. 6 diiu kien
Q khoang tuong ddi cao nay, thoi gian phoi heo phii hpp 120 - 210 pliut. Kit thiic qua trinh nay, do am ciia che heo 65 - 66%, ty le che heo dung 80 - 85%.
b. Vimg imh sang mat troi co dp dpi trung binh 0 viing nay dp dpi cua anh sdng mat trdi 1 40.000 lux < E < 80.000 lux, tuong iing voi viing cd dq dpi nay, nhiet dp khong khi thudng tir 32 - 38 "C Vi no thudng d thdi diem tir 8h00 - lOhOO va 14h00 - 16h00 ciia thang 6 - 9. (J vimg anh sang cd do dpi va nhiet dp nay, can cir vao dd thi 1 neu cho la che tiep xuc true tiep voi dnh sang mat trdi trong thoi gian ddi, thi se cd hien tupng tap la che, do tl bao la bi pha huy, hoac lugng am cua dpt che thoat ra ngoai cue bp, chii yiu thodt d nhung phdn la non hoac blip, trong khi do nuoc d cuong che chua thoat kip do can phai eo mot thoi gian dl dich chuyen vao 14
[2]. Tir do ddn din dpt che heo khong diu, cuong vdn tuoi nhung la lai kho tap dac biet la nhung phdn la non. D l dam bao chat lupng ta phoi heo chi d dp ddy 7-9 cm, qua trinh dao rii 10 phiit/ lan, cac che dp ky thuat dupc thi hien a bang 7.
Bang 7. Phoi heo che b 32 - 38°C trong viing anff sang cd dp dgi trung binh ^
Nhiet dp phoi heo
CQ
32-34 34-36 36-38
Thoi gian (PhiiO
60-75 45-60 30-45
Dp am con lai (%) 68-70 70-72 72-74
Nhan xet trang thai ia che
Mau xanh hoi vang, la mem, cuong tuoi Mau xanh hoi vang, la
mem, cuong tuoi Mau xanh hoi vang, la
mem, cuong tiroi
KHOA HOC CONG NGHE
Ung vdi khoang nhiet do nay, tuy theo nhiet dp cao hay thap ma ta phoi heo che, voi thai gian tir 30- 75 phiit. Kit thuc qud trinh phoi heo dp am cua che cdn lai 68-74%, la c h i cho sdc mau xanh hoi vdng, m I m mai. Che dugc chuyen ngay len mang heo voi dd day 12- 14 cm, diing quat thdi khong khi mat tir dudi len vdi thdi gian tir 6- 8 gid niia. Sau 2 gid che dugc ddo rii mot ldn, k i t thiic ciua trinh ndy dp am cua che heo cdn 63-64%, dot che m I m deo, d l udn, sdc la mdu xanh phii hpp cho qua trinh vd che.
c. Vimg anh sang mat troi co dp dpi cao
O vimg nay dp dpi cua anh sdng mat trdi la E >
80.000 lux, img vdi vimg ndy, nhiet dp ciia khong khi thuong > 38''C. Can cii vdo sd lieu bang 1, nd thudng d thdi dilm tir lOhOO - 14h00 cua thdng 6 - 9. Trong dieu kien nay do nhiet dp cua khong khi cao vd cudng dp chiiu sdng manh, d viing anh sang ndy thoi gian phoi che tir 24 - 35 phut da gay chay tap la che.
Vi dudi tac dung ciia tia tir ngoai, te bdo cua la che bi pha huy va mat nuac nhanh chdng vi vay d viing dnh sang nay khong nen phoi h l o che true tiip dudi dnh sdng mat trdi. N i u mudn thuc hien dugc qua trinh phoi heo che, phai dimg mai che nhdm giam bot dp dpi cua dnh sang mat trdi va nhiet dp khong khi.
IV. KET LUAni
Dp dpi cua dnh sang mat trdi va nhiet dd khong khi la hai dai lugng quan he ddng biin. Khi do dgi tang thi nhiet do khong khi cung tang. Thap nhat tir 6h 00 - 8h 00 vd 16h 00 - 18h 00. Trung binh tir 8h 00 - lOh 00 vd 14h 00 - 16h 00. Cao nhat tir lOh 00 - 14h 00, dac biet tir 12h 00 - 14h 00. Nhiet do va do am tuong ddi cua khong khi cd quan he nghich biin, khi
giam. Cao nhat tir 20h 00 - 6h 00. Trung binh tir 6h 00 - lOh 00 vd 16h 00 - 20h 00. Thap nhat tir lOh 00 - 16h 00 va dac biet tir 12h 00 - 14h 00. Nang lugng mat trdi trong nhiing diiu kien nhat dinh, hoan todn cd the dugc sir dung nhu bat ky mdt dang nang lugng nao khdc de heo che, cu the: O viing anh sang co do dgi thap E < 40.000 lux, khi nhiet dp khong khi 20- 29°C cdn phoi heo e h i vdi dp ddy 1- 3 cm, thdi gian 210- 300 phiit. cy 29- 38°C, phoi che 4- 6 cm, thdi gian 120- 210 phut, ddo ru 30 phut/ ldn. Ty le che h l o dung dat 80- 85%. O viing dnh sang cd dp dpi trung binh 40.000 lux < E < 80.000 lux, phoi che day 7- 9 cm, thai gian 30- 75 phiit, ddo ru 10 phiit/ ldn, k i t hap h l o mdng 6- 8 gid, do am cdn lai 63- 64%. O viing anh sang co dp dpi cao E > 80.000 lux, khong nen phoi heo che true tiip dudi anh sang mat trdi.
TAI LIEU THAM K H A O
1. Bp Nong nghiep va PTNT. Vu Khoa hpc Cong nghe vd Chat lupng thuc pham (2001). Tuyln tap tieu chuan Nong nghiep Viet Nam, Ha Npi 2001.
2. Dd Van Chuong (1999). Nghien ciin mot sd phuong phap heo la che trong san xuat che den vd cac yeu td anh hudng den chat lupng trong qua trinh heo. Luan an Tien si Ky thuat. Ha Ngi 1999.
3.1. A. Khotrolava (1985). Ky thuat che biin che.
NXB Nong nghiep. Ha Ngi 1985.
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WITHERING TEA BY USING SOLAR ENERGY Do Van Chuong Summary
There are many ways to wither tea leaves now. Using solar energy is one of the ways which is considered vei-y economical. In order to study direct-diying tea by solar, it is necessary to identify the temperature, relative humidity, illuminating power which change over the months and years. After using solar radiation with diferent illuminating power to wither tea, it is concluded that there is a relation between the duration of diying tea and the illuminating |)ower. Look at the hyperbola graph, 3 zones of radiation are identified: low illuminating power (E< 40,000 lux), medium illuminating power (40,000 lux < E < 80,000 lux), and high illuminating power (E > 80,000 lux). Experimentally, tea leaves can be dried at required rate if diying time is from 120 to 210 minutes, turning-over for each 30 minutes in low illuminating power zone. The proportion of tea that meet the requirement of diying is 80 - 85%. In medium one, diying time is just from 30-75 minutes, turning-over for each 10 minutes, and then further drying with withering trough for 6-8 hours, 63- 64% water content left. In high one, it is not recommended to diy.
Keywords: Withering tea, solar energy.
Ngudi phan bien: P G S . l ^ . Nguyin Hay
