ISIJ International, Vol. 57 (2017), No. 7
© 2017 ISIJ1173
ISIJ International, Vol. 57 (2017), No. 7, pp. 1173–1180
*
Corresponding author: E-mail: chengsusen@metall.ustb.edu.cn
DOI: http://dx.doi.org/10.2355/isijinternational.ISIJINT-2017-003
1. Introduction
Recently, low reducing agent operation of the blast fur-
nace has attracted much attention in the ironmaking process
owing to the phenomenon of global warming. With the
decrease of the coke ratio, the stable operation of the blast
furnace becomes very important. The blast furnace is a
countercurrent reactor involving the complex heat transfer,
mass transfer, momentum transfer, and chemical reactions
between ascending gas and descending solid particles. It is
one of the most important factors for stable operation of the
blast furnace to optimize the burden distribution. Because
the eciency of smelting is dominated by the gas distribu-
tion. Then the gas distribution is signicantly aected by
the burden distribution in the blast furnace. However, the
burden distribution in the blast furnace is determined by
the burden distribution in the hopper, the structure of the
hopper and the charging matrix. Therefore, investigation of
the burden distribution of the hopper and stock surface is
signicant.
Owing to the exibility and convenience of the bell-less
top system, the bell-less top system with two parallel hop-
pers and that with serial hoppers are widely applied to the
Effect of the Main Feeding Belt Position on Burden Distribution
during the Charging Process of Bell-less Top Blast Furnace with
Two Parallel Hoppers
Wenxuan XU, Shusen CHENG,
*
Qun NIU and Guolei ZHAO
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian
District, Beijing, 100083 P. R. China.
(Received on January 12, 2017; accepted on April 4, 2017; J-STAGE Advance published date: May 29,
2017)
Based on an actual 4 070 m
3
bell-less top blast furnace with two parallel hoppers in China, a full model
of bell-less top mainly consisting of a bunker, a main feeding belt, a switch chute, two parallel hoppers, a
central throat tube, a rotating chute and a throat of blast furnace was established in this study. Specifically,
the angle between the centerline of the main feeding belt and the symmetry plane of two parallel hoppers
is 22 degrees. Then the processes of coke charging into and discharging from the left hopper and right
hopper were calculated by the discrete element method (DEM) model, respectively. The calculation results
show that the burden distribution of the left hopper and right hopper was not symmetric, which caused
the asymmetric and uneven distribution of coke in the radial and circumferential direction of stock surface,
respectively. In the case of coke was discharged from the left hopper, the total volume of coke in the radial
region 1 to 9 was smaller than that in the radial region 12 to 20 of stock surface. And the total volume of
coke in the circumferential region 1 to 4 was larger than that in the circumferential region 5 to 8 of stock
surface. However, the burden distribution of stock surface was contrary when coke was discharged from
the right hopper.
KEY WORDS: main feeding belt; bell-less top; blast furnace; two parallel hoppers; DEM.
blast furnace. In addition, some blast furnaces are equipped
with the bell-less top system with three parallel hoppers
internationally. With the extensive use of the bell-less top
system in the blast furnace, many researchers studied the
particle movement and size distribution in the charging
process of the blast furnace. Some researchers established
the single particle mathematical model to predict the burden
falling point on stock surface,
1–8)
which provided the theo-
retical guidance for blast furnace operators. Additionally,
some investigators studied the size distribution and falling
point of particles by small scale experiments.
9–17)
However,
the information obtained from experiments or single particle
mathematical model on size segregation and ow patterns
is still limited. Therefore, more detailed work is needed in
order to understand the burden distribution in the hopper and
throat. Recently, Discrete Element Method (DEM) has been
extensively applied to metallurgical engineering, chemical
engineering, mechanical engineering, and so on, which can
easily capture the motion behavior and size distribution of
particles. Yu et al. investigated the inuence of particle
shape on size segregation in hopper,
18)
and the study indi-
cated that the irregular shape of particles has little eect on
the simulation. Zhang et al. analyzed the ow and segrega-
tion of particles in the charging process of blast furnace,
19)
and the study showed that the ow pattern was “mass ow”
in the upper part of the hopper, whereas was “funnel ow”