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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 do tirang. Mot mdy say ihdp vdi kel cdu Ihdp Iru ludn hodn ngoai, Ihdo lieu h^

khi 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 2 thdp sdy idm viec song song: Dudng kinhx

chiiucao moi thdp Id 1.9 m x 5.4m: Budng phdn phdi khi itdy Ihdp cd dm'mg kinh x chieu cuo Id 1.9 x 1.2m:

Khoi luang thdc chda cue dui trong mot Ihdp Id 5200kg. Qua_ ihu nghidm sdy lltdc. ngo vd do tuang thay

rdng: Co the xa todn bo nguyen lieu ra 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 do 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 do dong deu do 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 ra. khi 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 khi 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. khi 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 2 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) pham khac nhau, do it bi dao tron nen cac hat it

a nuac ta chtl yeu la tnay say tinh vi ngang. Uu hi giy vo, gia nguyen duac phoi sau khi siy.

dtem caa may say tinh vi ngang la gia thanh va 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. '^"^ '^^° ^^ ^ho khong dong dSu. Phai daO

*° L, TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014