Energy and Exergy Analyses of Rice Drying in a Novel Electric Stationary Bed Grain-Drying System with Internal Circulation of the Drying Medium

In our study, we developed a system to reduce both energy consumption and pollutant discharge during the drying process. We present a new technology, a stationary bed grain-drying test device based on the internal circulation of the drying medium (ICODM). A rice-drying experiment was carried out inside of it, and the influences of air temperature (AT) and air velocity (AV) on the energy and exergy efficiencies (EEE) as well as the improvement potential rate (IPR) and the sustainability index (SI) of the rice-drying process were studied. The following conclusions were obtained: when the rice was dried at a temperature of below 55 °C and an AV across the grain layer of 0.5 m/s, the average EEE during the drying process was 48.27–72.17% and 40.27–71.07%, respectively, demonstrating an increasing trend as the drying medium temperature increased. When the rice was dried using an AV across the grain layer in the range of 0.33–0.5 m/s and a temperature of 40 °C, the two values were 39.79–73.9% and 49.66–71.04%, respectively, demonstrating a decreasing trend as the drying medium flow velocity increased. IPR and SI were 4.1–8.5 J/s and 1.9–2.7, respectively, at a drying temperature of 30–55 °C and an AV of 0.33–0.5 m/s. These conclusions can provide helpful guidance for the optimization and control of the rice-drying process in terms of saving energy.

Reconstruction of Rice Drying Model and Analysis of Tempering Characteristics Based on Drying Accumulated Temperature

Previous research has shown that the accumulated temperature can describe drying processes as well as crop growth. To describe the mass and heat transfer processes in the rice drying process more accurately, a mathematical model of rice drying was proposed based on the drying accumulated temperature, and the optimal tempering ratio for conventional hot air drying was obtained through data comparison and analysis. First, it was proven that there was an exponential relationship between the moisture ratio and the drying accumulated temperature of rice. Second, by comparing and analyzing the fitting results of seven different drying mathematical models, the model with the highest fitting degree was selected and reconstructed to obtain the drying accumulated temperature–moisture ratio model. Finally, the new model was used to fit the results of two drying experiments without and with tempering, and the tempering characteristics of rice drying were proved by comparing and analyzing the coefficient difference between the two models. The results showed that the optimal tempering ratio was 3. This study thus provides a reference for rice drying process parameters.

Performance test of air input control system for paddy grain drying using in-store dryer

The control system is e series of a system that is very important in today’s technology. Wherewith control system can make the human job easy and get a good result. This study used a controlled In-Store Dryer to dry 100 kg of grain with an initial moisture content of 17,77% to reach 14%. The study results using a control system, the average ambient temperature of the three tests ranged from 32°C to 33°C, and the RH ranged from 64,8 % to 68,6%. At the same time, the average temperature was 36,7°C to 37,5°C, and the average RH was 49,9% up to 64,7%. The drying airflow speed at the fan input is 6,2 m/s and at the chimney 9,2 m/s. Moisture content during drying differs for each thickness depending on the location, with an average drying rate of 0,92%. During drying, the moisture content varied for each consistency depending on the site, with the drying rate at an average ISD of 0.92% w / hr. total electrical energy consumption of 32.57 kWh and energy in biomass combustion 1,416,600 kJ. The quality during rice drying starts from the initial moisture content of 17.78% to reach the final moisture content of 10.44%.

Proposal for improving of paddy rice drying process in dryers inclined pools

The operation of inclined type dryers for paddy rice is studied to improve their operation and efficiency, considering the variables of drying time, humidity distribution in the rice layer after drying and air velocities within the plenum. Simulating the distribution and velocities of the air flow before crossing the rice layer, the outlet ducts to the plenum are relocated and dampers are placed to distribute the flow evenly. On the other hand, it is proposed to replace the flat-type mesh with a zigzag-type mesh. To verify the proposed modifications, a scale model was built to determine the humidity and drying time variation inside the rice layer, obtaining more uniform moisture percentages within the rice layer and a decrease in drying time.

Rancang Bangun Rangka dan Pipa Pemanas Pada Mesin Pengering Padi

The climate change in Indonesia results in disruption of the rice drying process which only relies on sunlight for the drying process of rice grains so that during the rainy season farmers having problems on the process of drying rice grains. Thus, a new technology is needed in the process of drying rice grains. This technology is using a rice dryer. In the process of making a rice drying machine, there are several important components that must be designed properly, namely the frame and heating pipes which are the main components of a rice drying machine. The aim of this research was to design the frame and heating pipe for rice drying machines. From the design process, the testing phase is carried out, both machine testing and rice drying testing. The test results show that all machine components run well and the drying results show that the rice has decreased in weight after being put into the rice dryer with decrease is 5 kg to 4,9 kg or about 0,1%.