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

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54 POSTHARVEST INDUSTRY HANDBOOKTable 3.4. Minimum plies for bucket projectionsGrain Minimum plies when bucket projection is Beltelevator 8 cm 10 cm 13 cm 15 cm 18 cm 20 cm fabricLow-speed 4 4 5 5 6 6High-speed – – – 5 6 628 oz or 32 oz32 ozTable 3.5. Maximum belt plies vs diameter pulleys.Head pulley Maximum Minimum footdiam (cm) plies pulley diam (cm)516171769156789107 10122 12384653566676913.13. Singlebox type elevatorleg.seven- and eight-ply.) This splice is not suitable for belts more than seven plies thickbecause it is too stiff to pass tightly over the pulleys.The butt-strap joint may be used on belts of eight or more plies. Place one bolt foreach 25 mm of belt width, 10 mm bolts for belts less than 10 plies, and 15 mm boltsfor those more than 10 plies.Belt widths should be the bucket width, plus 25 mm. The pulley width should bethe belt width, plus 25 mm or more.3.14. Splicing elevatorbelts.AccessoriesFor servicing the elevator head section, particularly the drive mechanism, a platformfor working is needed. Access to this platform is usually by ladder equipped with asafety cage. A typical elevator with platform is shown in Figure 3.15. In someinstallations, joint or common ladders are used for two or more elevators or othermachines.
55 CONVEYING3.15. Elevator with platform,ladder, and safetycage. (Courtesy of CardinalDivision, LMLCorp.)Power requirementsThe theoretical horsepower (hp) requirements for bucket elevators may be obtainedfrom the equation:where Q = capacity in kilograms per minute, H = lift in meters, and F = 1.5 forelevators loaded on the down side of the boot, 1.2 for elevators loaded on the up sideof the boot. Actual horsepower requirements are 10 to 15% higher than thistheoretical value because of friction, power transmission, and drive losses. Forexample, horsepower requirements for a bucket elevator with 1,600 bu/h of paddyand a lift of 10.7 m loaded on the up side would be: (1,600 bu/h = 545 kg/minute)Therefore the next larger standard size electric motor should be selected.
Page 1 and 2: Chapter 3CONVEYINGIn the paddy post
Page 3 and 4: 47 CONVEYINGTypesBucket elevators a
Page 5 and 6: 49 CONVEYING3.6. Elevator discharge
Page 7 and 8: 51 CONVEYING3.7. Elevator head show
Page 9: 53 CONVEYING8.11. Boot section desi
Page 13 and 14: 57 CONVEYINGments vary with segment
Page 15 and 16: 59 CONVEYINGHorsepower requirements
Page 17 and 18: 61 CONVEYING3.24. Standard hangerbe
Page 19 and 20: 63 CONVEYING3.28. Drive arrangement
Page 21 and 22: 65 CONVEYINGWhen the auger is opera
Page 23 and 24: 67 CONVEYINGExample: Determine belt
Page 25 and 26: 69 CONVEYINGeither side of the belt
Page 27 and 28: 71 CONVEYING3.40. Self-aligning cam
Page 29 and 30: 73 CONVEYING3.44. Wing-type pulley.
Page 31 and 32: 75 CONVEYING3.47. Cross section ofc
Page 33 and 34: 77 CONVEYINGMost spouting is straig
Page 35 and 36: 79 CONVEYING3.54. Five-way distribu

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

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