Abstract:
The existing studies of threshing process of combin
e harvesters adopt the assumption of
constant mass, which is contradictory to the phenom
enon of separation of grains and
short stalks in actual threshing process. Therefore
, the characteristics of threshing and
separation are not accurately described. Aiming at
this problem, this study established
the tangential-longitudinal threshing and separatio
n test-bed with tangential-flow device,
auxiliary feed beater, and longitudinal-flow device
of tangential-longitudinal-flow
combine harvester and conducted experiments and ana
lysis of rice threshing with feed
rates of 5, 6, and 7 kg s
-1
. The results showed that the changes in rates of m
aterial flow
along the arc-length of concave in tangential-flow
device and longitudinal-flow device
were equal to the changes in rates of material dens
ity with time. In the process of
variable-mass and constant-mass rice threshing, whe
n the feeding rates were 5, 6, and 7
kg s
-1
in the test-bed, the flow rates from the tangentia
l-flow device were 4.07, 5.01, and
5.95 kg s
-1
, respectively. The average power consumption of th
e tangential-flow drum in
variable mass threshing process was higher than tha
t in the constant mass threshing
process by 2.16, 2.73, and 3.09kW
, respectively. The flow rate at the outlet of the
longitudinal-flow device was 3.34, 4.04, and 4.72 k
g s
-1
, respectively. The average power
consumption rate of the longitudinal-flow drum in v
ariable mass threshing process was
lower than that in the constant mass threshing proc
ess by 7.32, 10.44, and 12.17kW,
respectively. The results of material flow rate and
power consumption would offer the
basis for the design of longitudinal-tangential flo
w threshing and separation device.
Keywords:
Harvesting rice, Material flow rate, Power consump
tion, Tangential-longitudinal
threshing drum, Threshing and separation process, T
ooth structure.
