English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In order to acquire the coupling mechanism of the paddy flow, hot air and far-infrared radiation, an experiment bench based on the screw conveyor and grain collecting tank of combine harvester was set up, and then the orthogonal experiment with six factors and five levels was conducted using the dehydration rate (DR), increased crack percentage (ICP) and specific energy consumption (SEC) as indexes. The optimal combination of factors for each index was acquired and the experiment results show: the drying combination could achieve rapid drying with good drying quality and low energy consumption; the initial water content of paddies is the dominant factor for the DR, ICP and SEC; the hot air has more effect on the drying performances compared with the IR radiation. 摘要: 为了获取谷物流、热风和远红外场的耦合机理,以联合收割机的搅龙和收粮箱为基础,搭建了远红外热风联合 干燥实验平台,以干燥速率、爆腰增率以及单位能耗为目标,进行了六因素五水平正交实验,获取了各实验目 标最优的因素组合,实验结果表明:该嵌入联合收割机中的组合干燥系统能够实现快速、高质以及低能耗干燥; 水稻的初始含水率是影响干燥速率、爆腰增率以及单位能耗的主要因素;相比于红外辐射,热风对干燥性能具 有更大的影响。 INTRODUCTION The widely using paddy combine harvester significantly reduces the harvest time of paddy; moreover, the paddy should have high moisture when it is harvested in order to decrease the loss of it. Harvesting the high moisture paddy rapidly makes the grain-sunning ground not big enough for farmers to dry paddy efficiently, and thus many farmers lay out the paddy on the road or highway which may seriously affect traffic in China. Meanwhile, farmers’ use of sun drying totally depends on the weather; they have to stack the wet paddy at home and if there is continuous rainy weather, mildew appears. Although the stationary drying machine has been used since 2004 in China, it is inconvenient for the hilly area because of the excess carriage expense and energy consumption. One solution to solve the problems above is to design a combine harvester with the function of grain drying simultaneously, and the drying system should be energy-saving and quick-drying to synchronize the harvest speed of combine harvester. Many works have been done to reduce the energy consumption of the drying system such as optimizing the drying process, taking the new heating device, recycling the exhaust heat and so on (Niu X.H., Cao C.W., 1999; Chen K.J., Chen Q.C., Zhang Y., 2005). Since the cooling water and exhaust gas takes away more than 60% of fuel energy of diesel engine equipped on the tractor and combine harvester, recovering the waste heat of diesel engine to dry grain has been the concern of many researchers. Bai et al. (Bai J.W., Luo S.Q. et al., 2008) equipped a semi-drying system on a tractor powered by the waste heat, and their drying system could decrease the grain water content by 3 to 6 percent. Fei et al. (Xiang F., Wang L., Yue X.F.,2011) developed a vehicle-mounted heat pump–assisted fluidization drying system driven by the waste heat recovered from the jacket water of diesel engine and flue gas of the drying system; their analysis results showed that the actual specific diesel consumption can reach 0.081 [(kg Vol. 59, No. 3 /2019 INMATEH –  134 diesel)/(kg water)]. The hot air drying is often used for the method of recycling the heat waste of agricultural machinery to dry grain, and it usually requires a long period of drying time and a large amount of thermal energy (Celma R.A., Rojas S., Lopez-Rodriguez F., 2008); hence, it is not suitable for drying grain directly on the combine harvester because of the high harvest speed. To overcome the drawbacks of the hot air drying, infrared radiation has been integrated with it. Far-infrared convection combination drying is widely used for foodstuffs such as corn (RahmanianKoushkaki H., Nourmohamadi-Moghadami A., Zare D. et al., 2017), rice (Sarobol M., Teeta S., Pharanat W. et al., 2018), potato (Onwude D.I., Hashim N., Abdan K. et al., 2019) and so on. In contrast to pure hot air drying, the combined technique was found to accelerate heat and mass transfer, leading to a shorter drying time and better drying quality (Liu C.S., Shang T., Yang S.Q., 2017; Zare D., Naderi H., Ranjbaran M., 2015). Noting far-infrared convection combination can not only use the waste heat of combine harvester but also dry grain quickly with less damage to its quality, the new drying system equipped with far-infrared and supplementary hot air could dry paddy directly in the drying chamber embedded on the screw conveyor and grain collecting tank of combine harvester was proposed. Then a test bench was setup to acquire the coupling mechanism of paddy flow, hot air and far-infrared using the orthogonal test. MATERIALS AND METHODS EXPERIMENT BENCH The experiment bench designed is shown in Fig.1. A hot air blower pushes the hot air into the screw conveyor and grain collecting tank of combine harvester, and the hot air from the hot air blower simulates the hot air heated by the waste heat of combine harvester. The air temperature and velocity can be regulated by the voltage regulator 1 and the throttle, the actual air temperature and velocity can be detected by the air temperature and velocity sensors. Infrared (IR) radiator 1 and IR radiator 2 are embedded in the walls of screw convey and grain collecting tank and their powers can be regulated by the voltage regulator 2 and 3. The paddy is put into the hopper, and the screw conveyor driven by the motor promotes the paddy into the grain collecting tank. The paddy is dried by the hot air and far IR radiators. Hot air tube Screw conveyor of combine harvester

EXPERIMENTS ON PADDY DRYING MECHANISM OF FAR-INFRARED CONVECTION COMBINATION IN COMBINE HARVESTER