Physical Properties of Grains
5Julian Nicole Ann I. Garcia February 14, 20172013-68103 February 21, 2017Exercise No. 3Physical Properties of Grain CropsINTRODUCTIONIn the Philippines, grains are considered as staple food most especially the rice. It is important to determine the physical properties of grain varieties because the classification of grain types and varieties can be used as a basis for designing storage structures. It can also serve as a guide for milling machinery adjustments to obtain appropriate operational efficiencies. In this exercise, the different physical properties were determined. The first one is bulk density which is basically the ratio of the mass of the grains to a given volume, manipulating this formula, we can get the quantity of grain stored in a given volume, if the bulk density is known. Bulk density is measured in terms of standard weight divided by its volume. It also indicates the quality of the grain. The next physical property is angle of friction. This refers to the maximum angle at which the grain remains in equilibrium on an inclined plane or angle at which most of the grains slide against a flat material (such as plywood and aluminum sheet). There is also another angular property which is the angle of repose. This is formed when grain is poured on a flat horizontal surface, the slope of the sides of the mass of grain that was poured was measured.
The last physical property is the paddy grain dimension. This deals with the surface area of the grains. It includes length, width, and thickness in millimeters (mm) and diameter in case of round and physical grains. This property can also be used to identify the variety of grains and the type of storage applicable for the crop. So in agricultural engineering, this is important in designing rubber rolls and milling machines. In the case of corn, the size of the variety matters for the determination of starch it can produce. OBJECTIVESAfter the laboratory experiment, the student should be able to:Know and explain some common physical properties of rice and corn and,Understand the use of these properties in crop processing. MATERIALS and EQUIPMENT List of MaterialsEquipment and InstrumentsBates AspiratorBulk Density ScaleTriple Beam BalanceWooden PlateSteel PlateVernier ProtractorDial CaliperWorking Sample1000 grams paddy1000 grams yellow cornMethodsBulk DensityThis is measured using a bulk density tester. The weight of the grain in a container is divided by its volume. The first step made was to make sure that the sample was clean and free from foreign matter. Bates Aspirator was used to remove all impurities. The grain samples were then loaded into the hopper of the bulk density tester with the discharged bottom closed, after doing this, the grains were released by opening the discharge lever and the grains to fill the container under it. The excess grains on the top of the container were removed by scraping it using a wood, so that the amount of grains will just be leveled with the top of the container. The container was then weighed using the attached scale. This procedure was done three times for both samples, rice and corn and data were recorded.