tailieunhanh - Industrial Machinery Repair Part Episode 2 Part 6

Tham khảo tài liệu 'industrial machinery repair part episode 2 part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Mixers and Agitators 359 is acceptable for each application. The recommended range should include adjustments for temperature flow rates mixing speeds and other factors that directly or indirectly affect viscosity. Troubleshooting Table identifies common failure modes and their causes for mixers and agitators. Most of the problems that affect performance and reliability are caused by improper installation or variations in the product s physical properties. Table Common failure modes of mixers and agitators THE CAUSES THE PROBLEM Surface vortex visible Incomplete mixing of product Excessive vibration Excessive wear o 1 0 0 ế Excessive power demand Excessive bearing failures Abrasives in product Mixer agitator setting too close to side or corner Mixer agitator setting too high Mixer agitator setting too low Mixer agitator shaft too long Product temperature too low Rotating element imbalanced or damaged Speed too high Speed too low Viscosity specific gravity too high Wrong direction of rotation 360 Mixers and Agitators Proper installation of mixers and agitators is critical. The physical location of the vanes or propellers within the vessel is the dominant factor to consider. If the vanes are set too close to the side corner or bottom of the vessel a stagnant zone will develop that causes both loss of mixing quality and premature damage to the equipment. If the vanes are set too close to the liquid level vortexing can develop. This will also cause a loss of efficiency and accelerated component wear. Variations in the product s physical properties such as viscosity also will cause loss of mixing efficiency and premature wear of mixer components. Although the initial selection of the mixer or agitator may have addressed the full range of physical properties that will be encountered applications sometimes change. Such a change may result in the use of improper equipment for a particular application. 19 Packing and Seals All machines such as pumps and .