Catalytic flue gas turbine
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The catalytic flue gas turbine stopped operating suddenly due to a fault; there was severe vibration at the site. Upon inspection, it was found that 2 of the rotor blades were broken, while the other blades were also severely worn, and the bearing shells were damaged. The cause remains unknown; I seek advice from experts
First of all, I would like to ask: when your smoke extractor stopped working, did the main fan shut down on its own? 1. Is it possible that the smoke and dust content in your system is too high, resulting in poor separation of particles and severe wear on the blades? 2. Check the pipes before and after the smoke extractor to see if there are any hard objects present, such as small metal pieces or screws, and also check whether there are any marks on the blades. 3. Is the temperature at the inlet of the smoke extractor often too high, leading to damage to the bearing shells? 4. Check whether the amount of steam used in your smoke extractor is either too high or too low
A photo would help with the analysis! In most cases, blade failure is caused by an external object (such as a broken temperature sleeve or similar) hitting the blade; check to see if there are any foreign objects present ； Leaf wear is definitely caused by catalyst wear! As for the damage to the bearing shells, it may be due to insufficient lubricating oil, increased vibration after blade breakage, which causes wear of the bearing shells! It would be best to have a photo to take a look at!
The burnout of the bearing shells is caused by blade damage, which leads to a disruption in dynamic balance. Could you specify exactly where the fracture occurred on the blade – at the root or at the tip? I’ve seen similar issues occur in smoke turbine units at several companies before. In my opinion, the possibility of foreign particles being the cause is low, but it cannot be ruled out entirely. I think it would be advisable to take samples from the fractured blades for analysis, to examine the distribution of grain size and inclusions, and to also compare their hardness and impact resistance, in order to determine the root cause of the fracture. Additionally, during this period, factors such as the operating time of the device, and the manufacturer’s heat treatment processes used during the spraying of the moving blades can all be checked
The bearing bush burned out, causing the rotor shaft center to drop. It seems that your self-protection measures were not taken in time; during the idle operation, the moving blades struck the casing, causing it to break. Another option: a solid impacts the moving blade, causing it to break. Alarm or interlock for shaft displacement and vibration. Insufficient return oil from the high-position fuel tank caused the bearing shells to burn out. Check whether the oil pressure regulating valve is set too low.
Where is the range hood made, and what is its power rating? Has there been a gradual increase in vibration? Or a sudden rise?
Blade fractures in smoke extractors were frequent a few years ago, but have occurred less in recent years. The main reasons are: 1. High content of catalyst dust with large particle sizes, which causes erosion of areas under high stress such as the blade roots, leading to fractures； 2. The material of the moving blades is of poor quality; GH864 contains excessive amounts of harmful impurities such as sulfur. After Sinopec purchased a batch of imported rod materials in bulk, the problem of blade breakage has been alleviated to some extent ； 3. Catalyst scaling at the tip of the moving blades and friction within these blades; the high temperatures resulting from friction cause damage to the blades and also accelerate scaling. The moving blades suffer from prolonged bending moments, which leads to their fracture ； 4. Does the smoke extractor overheat frequently, thereby reducing the lifespan of the blades? 5. There have also been cases in which the insulation covering around the temperature sensors in certain factories came off, causing damage to the blades. Bearing failures are mainly due to secondary damage resulting from the loss of dynamic balance after a blade breaks
1 Conduct a historical record analysis of flue gas vibration values to check for any early signs. 2 Generally, it is the fouling of the catalyst on the rotor disc that causes vibration in the smoke extractor, ultimately leading to machine damage. After disassembly, attention should be paid to the details of damage to the smoke extractor, as well as the condition of the rotor and blades (at their roots); if possible, samples of the catalyst fouling should be taken for analysis. This problem becomes prominent after the use of olefin reduction catalysts. With imported catalysts, no such situation occurred. 3. A company resolved the problem of catalyst scaling in flue gas turbines by diverting the flue gas away from the turbine, thereby allowing it to \"spin idle\" (without any flue gas flowing through it, which caused the turbine to cool down; since the scaling substances expanded at a different rate than the metal, they fell off naturally). In fact, this \"risky\" method can solve the problem, but it is very dangerous.
The break occurred at the base of the blade; it has been in use with the smoke extractor for just 10 days, so it’s unlikely to be caused by catalyst erosion, and there was no impact from any foreign objects as well
Was the rapid temperature rise when starting the cigarette lighter the cause of the breakage? It’s still caused by the leaves having been in use for too long!
What is the steam temperature? Should water be included? The required temperature for cooling the steam in the smoke extractor’s rotor is 220–250 degrees.