Scaling problem on smoke extractor blades

Yes, there’s nothing we can do about this phenomenon either; we mainly clean the dirt once a week

It is mainly to control the catalyst fine powder content by managing the regenerator effluent. Controlling the regeneration temperature, analyzing heavy metals in the raw materials, increasing the amount of passivator added, and stabilizing the pressure in the two reactors.

Clear weekly? Cut the smoke extractor once a week?

For units equipped with smoke extractors, extra care must be taken in terms of technical and production management. If the blades of the smoke extractor get damaged, the cost of replacing them is roughly equal to the amount of electricity that could have been saved. . . . :lol

How could it be this serious? It’s necessary to thoroughly investigate the reasons and conduct an analysis.

Could you explain the method and steps for cleaning it weekly?

I’ve heard of online methods for removing scale; abroad, it seems that crushed walnut shells are used to scour away scale, and large rotating discs are also employed to cool the steam. I don’t know which one is used on the 2nd floor?

Please provide a detailed explanation upstairs; it will be very informative. The amount of cooling steam that can be supplied by the large wheel is limited, and the effect is mediocre. Last edited by chengkang on 2009-3-28 at 12:53.]

Given the continued deterioration of the vibration trends and the leakage at the butterfly valve at the flue gas extractor inlet, the flue gas extractor was taken out of the system on November 14. The high-temperature gate valve was closed to cut off the flue gas, after which the steam flow rate was increased to accelerate the change in temperature difference. Although the steam flow rate remained within the range of 0–3.6 T/H, the temperature difference increased to nearly 100°C. As can be seen from Table 3, after the flue gas supply was cut off, there was a significant change in the load on the smoke extractor; the scale on the rotor fell off unevenly, and the amplitude of the vibrations of the smoke extractor changed abruptly. The vibration levels surged to 93.3 μm within a few minutes before dropping again. At this point, the steam flow rate had reached its maximum value of 3.6 t/H. Due to the change in temperature differences, and as a result of the cooling steam acting on the rotor disc, large areas of scale on the rotor fell off, and the situation began to stabilize. The high-temperature gate valve was closed at 10:20, and by 10:57 the vibration of the smoke extractor had dropped below 10 μm, reaching the level observed at the beginning of operation after the overhaul of the flue gas turbine. Moreover, over the following 48 hours no fluctuations in vibration were detected, with the value remaining stable below 10 μm. It can be seen that the unbalanced mass on the turbine rotor caused by catalyst fouling has been essentially eliminated, and the deposits have fallen off.

It is mainly caused by an excessively high dust content in the flue gas and large dust particles. It is necessary to operate the pressure steadily to avoid pressure fluctuations, which can increase catalyst wear. The main air volume and various steam volumes should remain stable, without significant fluctuations. Select appropriate bed linear velocity and catalyst inventory to reduce the concentration at the inlet of the cyclone separator.

What type of smoke extractor do you have? First, identify the cause of scaling from a technical perspective, and then modify the equipment!

It is currently believed that the main reason is that the flue gas extractor deviates too far from its normal operating curve; for some reason, the butterfly valve of the flue gas extractor cannot be opened and remains below 20%, which leads to scaling and wear of the extractor’s blades. Details to follow

What catalyst is the original poster using? In many cases, it’s due to problems with the catalyst. 1. The catalyst lacks sufficient strength and is prone to breaking. 2. The regenerator pressure control is unstable. 3. High content of heavy metals in the raw materials (is it heavy oil catalytic cracking?). 4. How does the regenerator burn out, under oxygen deficiency or excess? In low-oxygen conditions, the flue gas temperature is low. 5. Catalyst type: Domestic olefin-reducing catalysts have a high content of rare earth elements, strong adhesion, and tend to form agglomerated scale. I hope the original poster can provide more information.

I believe this article should be useful to you. :) Abstract: To address the issue of abnormal vibration in the catalytic cracking flue gas turbine, condition monitoring techniques were employed to analyze the operating conditions of the unit and carry out fault diagnosis. It was found that the abnormal vibration of the turbine shaft bearings was caused by deteriorating operating conditions of the turbine, as well as by the sudden detachment of catalyst deposits that had accumulated uniformly on the turbine’s flow channels and blades due to scaling. At the same time, online descaling technology was applied to perform descaling on the steam turbine without shutting it down, ensuring its safe operation over extended periods of time. Keywords: catalytic cracking ； Flue gas turbine ； Condition monitoring ； Fault analysis ； Measures http://bbs.hcbbs.com/viewthread.php?tid=221314