hi'n SJ
KHOA HOC - CONG NGHE
MOT SO KET OUA NGHIEN ClKU XlT LY NHIET VO CA PHE LAM TANG NHIET TRj
Nguyen Dinh Tung' TOMTAT
Bdi bdo trinh bdy kii qud nghien ciru (hire nghiem vi xic iy nhiit vd cdphe ldm ldng nhiet tri ihdp cho vd cd phi sau khi xir ly trin thiit bi hogt dgng Hen tuc. Kit qud khdo sdt cho thdy^ vd cd phi sau khi xir ly co nhiel trf thdp ldng len ddng ke. hiiu sual lang len ciia nhiit irj dgt dugc loi da doi vdi md hinh nghien cieu ly thuyil vd nghien cim thirc nghiim ldn hrgt la 12,07% vd 13,22%. Han nira kel qud giiia md hinh ly thuyet va thuc nghiem khde nhau khong nhiiu, khodng 0,57% (doi vdi mdu thi nghiim 1), khodng 1,15% (ddi vai mdu thi nghiem 2).
Tir khod: Xir ly nhiet cd phe. nhiit tri thdp, vocdphe.
SOME STUDY RESULTS OF THERMAL TREATMENT OF COFFEE HUSK TO INCREASE LOW HEAT VALUE
Nguyen Dinh Tung' SUMMARY
The paper presents experimental study results of thermal treatment of coffee husk to increase its low heat value after being processed in a continuously operating machine. The results show that the low heat value ofthe treated coffee husk rises considerably; the increase efficiency of the heat value reaches a maximum in both theoretical and experimental study model with the percentage of 12.07% and 13.22%
respectively. Furthermore, the difference between theoretical and experimental results is insignificant, which is about 0.57% (for sample 1) and 1.15% (for sample 2).
Keywords: Thermal treatment of coffee husk, low heat value, coffee husk.
I. DAT VAN ©E
Doi voi Viet Nam hien nay, cix sau vu thu hoach cay trdng ndng nghiep, va hoac sau che bien cac phu pham ndng-, lam nghiep du thira chua dugc su dung con rat lon, trong do co k l den la vo ca phe [1,2], Ddi voi vo ca phe co dac diem kich thuac vo sau che bien khdng ddng deu, hon ntia phan tan rdng rai phu thudc vao cac CO sd che bien nen chi phi van chuyln va luu trir cao, dac biet khdi lupng rieng nhd bdi the "mat dp" nang lupng thap [1-3]. Vi v$y n l u CO nhu cau lara nhien lieu ddt true tilp se gap nhilu khd khan vi kho chay triet d l gay khoi bui, d nhiem mdi trudng. Chinh vi vay viec nghien ciru cdng nghe xir ly nhiet nhdm khde ' PGS. TS. Vi?n nghien ciiu thilt ki chg t^o may nong nghiep.
.v-
TAPphuc cac han che neu tren va nang cao duoc nhiet tri lihi lam nhien H$u d6t la rit cSn thilt. d day cong nghe xit ly nhiet la mpt qua trinh
"nhiet phan nhe", doi voi vo ca phe dugc th\rc hien a nhiet do vao khoang tu' 300°C dSn 400°C.
Nguyen lieu sau xir ly (char) co cac dac tinh mat d6 nang lugng va nhi$t tri cao hon nhiju so voi vo ca phe truoc khi xu ly.
II. VAT LIEU, PHirONG PHAP VA THIET BI NGHIEN ClTU
- Val lieu nghien cieu: Vat lieu nghien ciru trong bai bao nay la vo ca phe du thua sau che bien (hinh 1), co dac tinh la kich thuoc hat nguyen lieu khong d6u nhau, co nhiju "canh" to Ian nhieu bui nho min, khdi lugng rieng khoang 300-350 (kgW) [3].
CHl CONG NGHIEP NONG THON - SO 20 - 2015
KHOA HQC - CONG NGHE
Tren hinh 2, thiet bi hoat dpng theo nguyen ly lien tuc kieu trdng quay, nguyen lieu se dugc nap lien tuc tir dau phia vao sau do dugc dao ddu ben trong va hap thu nhiet tir ngudn nhiet cap vao, sau dd nguyen Heu dugc dua ra lien tuc phia dau ra cua trdng.
Jl) Hinh 1. Vdt lieu thi nghiem (vo cdphe)
truoc khi xu ly
- Phuffng phdp nghien cd'u: Trong bai bao nay da sir dung phuang phap nghien cuu ly thuyet va phuang phap thuc nghiem.
- Thiit bi do diing trong nghien cii-u: Trong nghien cuu nay cac thiet bi do dugc sir dung gdm:
a- Can de xac dinh khdi lugng nguyen lieu truoc va sau xir ly;
b- Thilt bj do nhiet dp cim tay kieu sijng bin (Ebro - CHLB Dire);
c- May do liru lugng va van tdc gio (Testo - CHLB Dire);
d- May do dp Am vat lieu trudc va sau khi xu ly nhiet;
e- Cac sensor cam bien nhiet dp de xac dinh nhiet do ben trong trdng xir ly nhiet [2,3].
- Thiit bj nghien ciiu: Thilt bi nghien cim dugc dl cap trong bai bao nay c6 nguyen ly hoat dpng va kit cku nhu tren hlnh 2 va hinh 3.
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(5 L d — i
•
o
1
oj
At)
01
^ . . (
Hinh 2. Nguyen ly hogl dgng vd kel cdu cua thiit bi thi nghiem [3]
Hinh 3. Nguyen ly cdu tgo vd hogt dgng cua sdngphdn logi [3]
1- ChSn de de tao rung dong; 2-. DTa rung co so;
3- Cac that sang; 4- Gong sang; 5- Khay sang;
6- Sang sau phan loai tren; 7- NSp
Tren hinh 3 la nguyen ly cau tao va trinh tu bd tri sang tren may phan loai nham phan loai ra cac hat vd ca phe co kich thuoc khac nhau.
III. KET QUA VA THAO LUAN
Khi nghien cuu ve xir ly nhiet nguyen li?u vd ca phe mgt trong nhimg yeu cau "bat budc"
dd la phai lya chgn nguyen lieu c6 chung mgt hinh dang (form) dac biet la cd kich thudc nam trong mdt viing nhat dinh. Bdi vay ngudi ta sir dung phuang phap phan loai hat theo kich thudc. Trong bai bao nay tac gia da sir dung phuang phap phan loai hat theo sang phan loai cd nguyen ly nhu tren hinh 3 de lira chpn dugc viing kich thuoc hat cho vat lieu thi nghiem. Co sd khoa hpc viec phan loai lua chgn viing kich thudc hat nguyen lieu hgp li duoc xac dinh bdi cac phucmg trlnh sau.
- Cac ldp sau phan loai [3,6]:
TAP CHI CONG NGHIEP NONG THON - SO 20 - 2015 29
KHOA HQC - CONG NGHE
<!J(A) =
J/-Arf,
Trong do vai; (1)
(2) Do dd chia ra lam hai thanh phan ty le nhu sau:
Ham phan bd mat dp:
_ Phankhoiluong(d^,„ ...d) Tongkhoiluong{d^^^...d^^^.^) Ham phan bd tich lily:
f) (j\_ Phankhoiluong{d^^^...d) (3)
Tongkhoiluong{d^^^^ •••'^max) (4) Qua phuang trinh (1) din (4) cho thSy trinh tu sap xep sang trong qua trinh phan loai va quy lu|t cua ham phan bd mat do khi phan loai kich thudc (kiem tra mau) nhu tren hinh 4.
1.9
_ _i_9a . . -..Vs
A9
ThCi tv K^p s^ng/b d , = 3 0 | . m "^
ds = 25 (im d . = 20 fim d j = 15 [im d ; = 10 nm d , = 5 nm
J [ l i m ' ]
*
#
f ^
•> 111 -v u ! S i n 5 5
ml
iu66 ^ b i m ]
Hinh 4. Trinh tu sdp xip sdng trong qud trinh phdn logi vd bieu do hdm mat do phdn bS
kich thuac hgt [3]
Thi>V"*P*Sngrt)iiuil4 (l[|,mj
Hinh 5. Trinh tic sdp xep sdng trong qua trinh phdn logi vd bieu dd hdm phdn bd tich Wy
kich thudc hgt [3]
Tuong tu ddi vdi ham phan bd tich liiy se dugc the hien nhu tren hinh 5.
Qua phan tich nhu tren cho Xhiy, kit qua nghien cuu thuc nghiem ddi vdi vd ca phe khi phan loai kich thudc dugc trlnh bay nhu tren hinh 6 va 7.
Khoang Kith t h w c ( p i |
Hinh 6. Bieu do kit qud phdn logi kich thuac hat vo cdphe
Qua bieu dd 6 cho thay viing kich thudc dugc lya chgn de lam nguyen lieu cho nghien ciru thuc nghiem nim trong khoang d250 - d315mm, chiem khoang 80% khdi lugng, quy luSt nay tuan theo dung quy tuat ciia co sd ly thuyet nhu hinh 4.
Kich thifoc hft il(|iin|
Hinh 7. Bieu do ket qud phdn loqi kich thudc hgt vd cd phe theo hdm Q^
Qua bieu dd 7 cho thSy quy lu^t phan bo theo ty le % khdi lugng ciia dai kich thudc hat tuan theo diing quy luat ly thuylt nhu tren hinh 5.
30
KHOA HQC - CONG NGHE Tir ket qua phan loai hat nhu neu tren, vd ca
phe cd kich thudc nkm trong khoang (200-300
|am) sau dd dugc tien hanh thi nghiem xu ly nhiet tren thiet bi cd nguyen ly ket cau nhu tren hinh 2. Thi nghiem dugc tien hanh vdi vat lieu cd do am dau vao khoang 11,56% dugc tiln hanh tren thiet bi xu ly co nguyen ly rang trong quay vdi sd vdng quay lam viec khoang 4-5v/ph (ling vdi chi sd bien tan la 20-25 Hz), sd vdng quay cua trdng cd the dieu chinh dugc thdng qua bien tan. Thi nghiem trong dieu kien nhiet
dp do dugc tai 3 vi tri VTI, VT2 va VT3 ddi vdi 3 mau vat lieu Vd ca phe 1, Vd ca phe 2, Vd ca phe 3. Thiet bi xu ly cd nguyen ly hoat dpng lien tuc nen nguyen lieu dau vao vdi 11,56%
3m, san pham ra sau khi xii ly cd dp am khoang 0,43 din 0,54%. Vdi dp im nay nhiet tri cua nguyen lieu trudc va sau xu ly cd gia tri tuang irng la 17,4 kJ/kg va 19,5kJ/kg. Chi tilt han vl kdt qua cho timg mau thi nghiem dugc trinh bay nhu tren bang 1.
Bdng 1. Ket qua thi nghiem xir ly vo Cd phe (khoi luang rieng VL trudc xic ly (kg/m^): 23 7)
TT
01 02 03
Loai ng.Iieu
Vd ca phe 1 Vd ca phe 2 Vd ca phe 3
Do am
(%)
vao 11,56 11,56 11,56
ra 0,54 0,46 0,43
Nhiet dp trong thifa bi xir ly ("C) VTI
420 416 412
VT2 380 378 372
VT3 268 265 263
Chi so bien tan (hz)
25 20 20
v/p 5 4 4
Thai gian xirly (ph)
12
Nhiet tri Hu (kJ/kg) vao 17,4 17,4 17,4
ra 19,6 19,7 19,3
Kit qua vl san pham sau khi xu ly d cac che dp thi nghiem khac nhau cho ta mau sac cung khac nhau, danh gia cam quan thdng qua mau sic san pham nhu tren hinh 8.
Hinh 8. Hinh anh mau sac cac mau thi nghiem vo cd phe de ddnh gid lheo cdm quan Tren hinh 8 cho thay cd mau san pham tuong ling vol 3 mau khac nhau, do la: mau sang, mau tdi sSm, va mau nau, voi 3 mau sac
khac nhau nhu vay chac chan nhiet tri thap cua ba mau nay cung se khac nhau. Cu the v& gia tri nang lugng theo nhiet tri thap cua san pham da dugc phan tich trong phong thi nghiem Hda dau tgi trudng Dai hgc Bach khoa Ha Ndi, ket qua chi tilt dugc dien ta tren dd thi nhu hinh 9.
Ngoai ra, tren hinh 9 ciing cho ta thay ket qua so sanh ve dp lan ciia nhiet tri sau nghien cuu bang thuc nghiem tren thiet hi xti ly nhi?t (hinh 2) da phan tich trong phong thi nghi?m Hda D§u trudng DHBK Ha Ndi va dupc so sanh vdi ket qua tinh toan theo md hlnh ly thuyet tren may tinh l4y sd lieu tir thuc nghiem lam thong sd dau vao de tinh toan.
TAP CHI CONG NGHIEP NONG THON - SO 20 - 2015
KHOA HQC - CONG NGHE
D 6 thi bieu diln cac m6l quan ii4 giira ham iu^ng chit bfic va nhi^t tri vol d$ ^m cua nhian ll^u vo ci phe
111 Iir^i9 ChAt b
hinohllm CFO-CFZ
Hinh 9. So sdnh gid tri nhiet tri cua vo ca phe khi nghien cuu ihirc nghiem vd ly thuyet Vat lieu sau qua trinh thi nghiem ta thu
dugc cac mdu cd dp am thap hon nhieu lan so vdi dp im ddu vao, cac mau vat lieu nay da dugc dua di phan tich tai phdng thi nghiem Hda Dau trudng DHBK Ha Ngi de xac djnh ham lugng chit bde cdn tdn du trong nguyen Heu va nhiet tri cua ciia cac mau thi nghiem ddi vdi vd
Bdng 2. So sdnh ve hieu sua! cua nhiet
ca phe truoc khi thi nghiem, ket qua nhu tren hinh 9. Ngoai ra tren bang 2 trinh bay ket qua cudi ciing dugc so sanh de danh gia mtic dg nang cao dupc gia tri cua nhiet tri thap cho v6 ca phe tnroc va sau xii ly nham xac djnh ro hon hieu qua ciia qua trinh thong qua hieu suat nang cao dat dugc.
tri thdp dd dirac ndng len sau khi xie ly
M l u vat lieu nghien ciru (Vo ca ph6)
So sanh v<yj nghien ciru ly thuyet H u j
(KJ/kg NL) HU_TTLT (KJ/kg NL)
1 1%)
So sanh voi nghien cu'u thu'c nghiam Hu_o
(KJ/kg NL) Hu_rrLT (KJ/kg NL)
1 B- Vo ca phe
(%)
CF_1 CF 2
174 17,4
195 19.5
12.07 12.07
17.4 17.4
19,6 19.7
12.64 13.22
IV. KET LUAN
Ket qua cho thay vd ca phe sau khi xii ly nhiet tri thap tang len dang ke, hieu suat tdng len cua nhiet tri dat dupc tdi da ddi vai md hinh nghien ciiu thuc nghiem so vdi ly thuyet lan lugt la 13,22% va 12,07%. Hon nira kk qua giiia thuc nghiem va ly thuyet khac nhau khdng nhiSu, khoang 0,57% (ddi vdi mau thi nghiem 1), khoang 1,15% (ddi vdi mau thi nghiem 2).
Tai lieu tham khao
[1]. Nguyen, Dinh Tung (2009). Theoretische und experimentele Untersucliungen zur energietische Nutzung von landwirtschaftlichen AbfSllen aus Vietnam.
Dissertation Universitat Rostoclc, Deutscliland.
[2]. Nguyen Dinh Tiing v i cs. (2014): Nghien ciiu thiet kt, ch^ tao 16 Ichi hoa lien tyc phu phim nong nghiep 32
(vo trdu, loi ngo) quy mo cong nghi?p, De t^i nghien ciJai cap Nh4Nu6'c2014, BO Cfing Thuong.
[3]. Nguyin Dinh Tiing vk cs. (2012)' Nghien ciru cong ngh? xir ly nhi^t phy phS phSm nong nghiep de tao viSn nhiSn iieu (pellet) c6 nhi?t trj nang cao, De tai nghien ciju c a p BQ 2012, Bp Cfing Thuang.
[41. Martin Kaltschmitt, Hans Hartmann, Hermann Hofbauer. 2011. Energie aus Biomasse, 3 Auflage, Springer Beriin Veriag Springer Verlag.
[5]. UNDP. 2005, Biomas Energy for Heating and Hot Water Supply in Belarus. Best Practice Guidelines, Part A: Biomass Combustion.
[6]. TOMAS, J. (2015). Mechanische Verfahrenstechnik. Skript zur Voriesung. Universitat Magdeburg, Deutschland
N g i y n h a n b a i : 15/11/2015 NgSy p h a n bifn: 05/12/2015 N g u o i p h a n bign: PGS.TS. Bui HAi T r i k , HQC vien N o n g nghifp Viet Nam.
TAP CHI CONG NGHIEP NONG THON - SO 20 - 2015
