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Pressure especially dynamic pressure on the silo wall is crucial for the silo design, and it is difficult and intractable to study and discuss the pressures on the silo wall during discharging. In order to study the static pressure in the state of grain storage and the dynamic pressure under the state of central discharging, the model silo with a diameter of 400 mm and height of 700 mm which based on a reinforced concrete silo was made by aluminum. Taking the wheat as the storage material, the pressure tests of static storage and central discharging were carried out under the conditions of 100%, 80% and 50% volume of silo respectively, and the measured results of pressure were compared with the calculation results of relevant standards of China, Europe and the United States The experiments results of the static side pressure showed that the deviations rate between the measured value of the static side pressure of the model silo with the calculated value of China stangards were the smallest, while it was biggest compared with the United States standard. The three measured values of the static side pressure were more than the calculated values of China’s standard, that was 600 mm away from the top surface of the storage under 100% of silo volume, 160 mm away from the top surface of the storage under 80% of silo volume and 250 mm away from the top surface of the storage under 50% of silo volume, but the measured values were less than the calculated values after security correction. The measured values of static side pressure of the model silo were all less than those of European and the United States standards, the European and the United States standards were more security than China’s, the China's standard safety margin should to be adjusted. The test results of the dynamic side pressure of the silo wall showed that the dynamic side pressure of the same measuring points were different when the top of storage was in the whole flow state for the different initial silo volume when the storage was discharged to the same height, The dynamic side pressure of C1 (100 cm from the lower edge of sido wall) was 3.376 kPa when the 100% silo volume was discharged to 50% silo volume, and it was 1.528 kPa when the 80% silo volume was discharged to 50% silo volume. The phenomenon of overpressure occurred in the process of wheat from mass flow to tubular flow. The maximum overpressure coefficients of the 100%, 80% and 50% silo volume were 2.76, 2.90 and 2.68. The positions of occurring tubular flow gradually decreased at 100%, 80% and 50% silo volumes, it indicated that the location of tubular flow was related to the initial storage volume, the smaller the initial storage volume, the lower the location of tubular flow occurred on the top surface of storage. When discharging at the same port, the slope of the curve of grain height with time was about 16.1, i.e. the rate of grain unloading was the same, and the peak time of dynamic side pressure at the lower measuring points was later than that of the upper measuring points The study could provide a basis for the compilation and revision of silo standard and a reference for the design of grain silo. [ABSTRACT FROM AUTHOR]

Untreated agricultural waste results in significant environmental pollution and reduces economic efficiency in The Three Gorges Reservoir Region. Ensiling is a method used to improve biowaste-to-resource systems and enhance the efficiency of resource recycling. Nutrient-rich citrus waste are suitable raw material for ensiling in China, but unsuitable for large-scale ensiling. In this study, citrus waste and other agricultural by-products were used to ensile as livestock feed in a family-scale silo. Spatial variation in microbiome composition and silage quality was analyzed in the bunker silo. From the top to the bottom of the silo, the crude protein, crude fiber, and pectin contents all increased, while the loss rate of dry matter decreased, indicating that the silage quality was better in the lower section of the silo. Spatial variation in temperature, pH, and moisture significantly influenced silage quality by influencing the composition of the microbiome. Undesirable Enterobacteriaceae and Trichocomaceae were replaced by Lactobacillus , Saccharomycetaceae , Sphingobium , and Pediococcus during ensiling. Proteolysis was mainly due to the decomposition of crude protein and further hydrolysis of soluble protein by Sphingobium , Brevundimonas , and fungi. Crude fiber and pectin were primarily degraded by unclassified_o_Saccharomycetales and norank_o_Eurotiales. The pH of the silage decreased from the top to the bottom of the silo as well from the outside to the center, which is attributed to the presence of Lactobacillus and Pediococcus. More homofermentative lactic acid bacteria should be added to raw materials that are positioned higher in the bunker silo to improve silage quality. The reuse of agricultural waste as silage in Changshou Agricultural Park of the Three Gorges Reservoir Region could result in increase in annual profits of $8,282.50 USD; however, the waste handling expenses totaled $8,416.00 USD. The application of this BTR method will reduce the shortage of fermented feed and result in significant economic benefits. Image 1 • Ensiling of agricultural waste is an effective way to reuse waste as resource in China. • A family-scale silo was better suited for citrus waste ensiling. • The quality of silage decreased from the top to the bottom of the silo. • Temperature, pH, and moisture affect silage quality by influencing the composition of the microbiome. • Lactobacillus and unclassified_o_Saccharomycetales are the main microorganisms present after ensiling. [ABSTRACT FROM AUTHOR]

Silo is widely used in grain, logistics, electric power, metallurgy and other industries. Therefore, the reasonable design of silo structure is the key. China is a large country of grain production, with application of the modern granary environmental protection, energy saving, green and other concepts, the cylinder wall is higher, and larger diameter, occupies less land, saves resources of the silo and is more and more in line with the future development trend of granary, and with the trend of rapid development around the world. With the increasing height and diameter of silo, the problem of failure in silo discharging is becoming more prominent. The dynamic lateral pressure of grain silo during discharging is the major cause of silo failure. In this paper, based on the indoor grain silo discharging model test, the whole process of the silo center emptying was recorded with high-speed camera, the flow pattern of grain was analyzed with image processing technology, and the dynamic pressure generated during the discharge process was measured. Based on this test, the particle flow code (PFC3D) was used to carry out numerical simulation to track the movement of specific particles in the test. By comparing the results of the experiment and the numerical simulation, the mechanism of overpressure in the discharge of the silo was explored. Through this study, in the process of discharging in the center, there were two kinds of flow states, the mass flow and the tubular flow. At the beginning of the discharge, the stored material flowed as mass flow. After a period of time, the upper part of the material flowed as mass flow, the bottom of the storage was a tubular flow, and the mass flow was in the high diameter ratio close to 1 of the height position to convert to tubular flow. When the discharging height reached 1.1m, the stored material flowed in tubular flow until the discharge was completed. Both the dynamic lateral pressure and the static lateral pressure increased with the depth of the measuring point, and the dynamic lateral pressure was greater than the static lateral pressure. At the beginning of the discharge, the dynamic lateral pressure measured by the silo suddenly increased, and then the dynamic lateral pressure value decreased with the continuous reduction of the storage height. The overpressure coefficient measured by the three groups of sensors was larger in the height range of the high diameter ratio close to 1, and the overpressure phenomenon was obvious. In the process of silo discharging, the speed of tubular flow of the bottom stored material was greater than the speed of the mass flow of the middle and upper stored material. There was a pressure arch at the junction of the two flow states, and the existence of the pressurized arch hindered the normal flow of the upper stored material, which led to the self-weight of the stored material and the additional force caused by the change of momentum was almost entirely by the arch, resulting in the increase of the dynamic lateral pressure and a significant overpressure phenomenon. [ABSTRACT FROM AUTHOR]

Underground mine caving may induce collapse of the ground during ore caving, particularly when there is a loose material on top of the mine. In the present paper, a laboratory test is performed to model this mining problem which is followed by a particle flow simulation to simulate the interaction and movement between the two materials. For this nonhomogeneous problem, an interesting columniform channel for the loose material is formed during the drawing in both the experiment tests and the numerical modeling. The formation of this channel greatly affects the efficiency of ore drawing and the stability of the mine caving. The numerical modeling can be used for the optimization of ore drawing, ore drawing management and the prediction of ore loss and dilution indexes. The importance of the moisture content on ore drawing process and the efficiency of ore drawing are also investigated by both experimental and numerical tests, and useful results are found from the present study. [ABSTRACT FROM AUTHOR]

The scientific rationality of farmers' grain storage technology and equipment is crucial for the biosecurity of grain in the main grain-producing areas represented by Northeast China. In this paper, four farmer grain storage mock silos of different widths were used as a means to track an experimental cycle of grain storage. The absolute water potential of corn in all four silos at the beginning of the experiment was greater than the absolute water potential of air, prompting moisture migration from the grain interior to the air and down to about 14%. Moisture was influenced by wind direction, and moisture decreased faster with better ventilation on both sides of the grain silos. Therefore, grain silo width has a significant effect on the drying effect under naturally ventilated conditions of maize ears. This research focused on the determination and assessment of mycotoxin contamination under farmers' storage grain conditions and analyzed the effect of silo structure on the distribution of mycotoxin contamination. When the width was too large, areas of high mycotoxin infection existed in the middle of the grain silo, and ventilation and tipping could be used to reduce the risk of toxin production. This study proved that reasonable farmer grain storage techniques and devices in Northeast China can effectively protect grain from mycotoxin contamination. [ABSTRACT FROM AUTHOR]