Technical handbook for the paddy rice postharvest industry in ...

77 CONVEYINGMost spouting is straight steel pipe with flanged or unflanged ends, depending oninstallation requirements. Spouting 15 cm in diameter is usually available in 14 or 12ga; 20 cm is available in 10, 12, or 14 ga. Standard 22.5°, 45°, and 60° elbows areavailable. Adjustable elbows that make installation much easier are also available.For capacities of 1,500 bu/hour (30 t/hour) or less, 15-cm spouting and valves areadequate. For capacities from 1,500 to 3,000 bu/hour (60 t), 20-cm spouting is used.From 3,000 bu to 4,500 bu/hour (90 t), 25-cm spouting is used.The impact of falling paddy is extremely abrasive and rapidly wears out spoutingand elbows. A grain trap such as that shown in Figure 3.50 is used where fallingpaddy would cause excessive wear on the elbow. The abrasive action of the paddy isabsorbed by the trapped grain and saves wear on the elbow.3.50. Grain trap used toreduce wear on elbows.3.51. Two-way valve withbucket-type gate.