Are there any special features in the smoke pipe before the catalytic smoke inlet?
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Given that the flue gas extractor has high requirements regarding solid particles in the flue gas, are there any special measures in the flue gas pipes before it enters the catalytic reactor to prevent such particles from falling out? Also, the smoke exhaust outlets of the extractors I saw before were all directed downward, but the extractors used by our company now have exhaust outlets that point upward. . Is there any difference? This post was last edited by chengkang on 2009-4-14 21:48]
The smoke pipes in front of the smoke extractor, including those with three swirl outlets, are unlined. The extractor operates at a speed of 6400 revolutions per minute; it’s unimaginable what would happen if the lining came off and fell into the extractor. The exhaust outlet of the flue fan must be of the cantilever type; the flue fan in my catalytic device is a single-stage cantilever type, with smoke entering axially and exiting radially
Most of the exhaust ducts for smoke extractors lead upward, with a small portion leading downward.
The smoke pipes from the triple rotor outlet to the smoke extractor are unlined. To prevent the lining from falling off and ending up inside the smoke extractor, thereby damaging the blades and causing accidents. As for smoke extractors, most of them have upper exhaust, but there are also those designed with lower exhaust; the difference between the two is not significant. Generally, it is believed that exhaust fans have their outlets directed downward, resulting in a uniform distribution of the exhaust gas and good flow patterns; however, such fans require more space for their foundations. There is no definitive conclusion as to which exhaust method is better at present. Upper and lower exhausts have nothing to do with whether it is a cantilever design; the statement regarding the 2nd floor is incorrect.
The flue gas inlet pipelines are all hot-wall pipes without lining； However, due to the high temperature, the amount of thermal expansion is significant; therefore, it is necessary to consider using expansion joints to absorb this expansion during design. The expansion joints must be pre-stretched during installation, and proper marking systems should be in place during startup and shutdown processes to monitor whether the expansion and absorption are proceeding normally. Otherwise, the chimney may be damaged.
The flue gas extractor for the catalytic unit in our facility is also a single-stage cantilever type manufactured by Lanlian; the flue gas enters axially and exits radially. The inlet and outlet areas have no lining, and to date there has been no instance of the lining falling off and causing damage to the extractor
The exhaust method at the outlet of the smoke extractor has little to do with whether the inlet pipeline is lined or not! Whether exhaust occurs from above or below is a matter of choice when selecting the extractor; regardless of the type, the inlet pipeline must be installed as mentioned on floor 5, and expansion measurements must be taken during startup and shutdown!
The installation requirements for the exhaust fan’s inlet pipeline are very strict, and they largely determine the future operating performance of the exhaust fan; therefore, strict attention must be paid during the installation process! ! ! ! It must! ! ! The dimensions of pipeline pre-stretching, the selection and use of hinge-type expansion joints, and even the quality of pipeline insulation—all of these need to be carefully considered!
The main devices in the flue gas extractor inlet pipeline are gate valves and butterfly valves. The pipeline does not have a lining; to protect the flue gas extractor, the amount of catalyst dust in the recycled flue gas must be strictly controlled. If the level of dust in the flue gas is too high, the butterfly valve should be closed to make adjustments to the reaction process. In severe cases, it is necessary to shut down the flue gas extractor. The valve channel should have purge air to remove the catalyst. As for the smoke extractor, there is axial air intake and radial air outlet at the top and bottom, I guess; this is related to the layout of the device
It is essential to choose high-quality expansion joints for the inlet pipelines of the flue gas engines, and the amount of expansion must be calculated carefully during installation. Since the commissioning of our facility, we have used two such flue gas engines (including those that have been modified); the design of their outlet pipelines, with an upward orientation following the principle of \"round above and square below,\" has proven to be effective.
The inlet pipeline of the smoke extractor is not lined; in the design phase, to reduce losses of kinetic and thermal energy, the length of the inlet pipeline is kept as short as possible. Therefore, multiple expansion joints are installed at the inlet of the smoke extractor to maintain the tension in the pipeline. It also serves to protect the vibration of the smoke extractor. As for the material, it should be selected after verification and calculation by the design institute.