Production using a four-stage charged furnace for transformation

What do you want to say? Find a way to get rid of the four-stage electric furnace. But judging from the transition temperature, it should work. The temperature at the four inlet sections is ensured by four outlet sections and two outlet sections. Therefore, the level of gas concentration is highly related to the conversion rates in the four stages. A temperature rise of 25 degrees over four stages results in only one rotation, so the total number of rotations is likely around 97. Suggestions: 1. Increase the inlet temperature of each section to see if it can improve the conversion rate. At the beginning of driving, it is necessary to make many adjustments, observe trend changes closely, and collect and analyze data extensively. 2. Check whether the heat exchanger has tubes passing through it and for any short circuits in the gas flow. Slightly increase the acid absorption temperature. 3. Increase the gas concentration to around 9%; I think there is still room for improvement in both negative and positive pressures, and monitor the changes in conversion rate after raising the gas concentration.

The temperatures at the three inlet and outlet points don’t seem to be correct. It is recommended that you first check the heat exchanger to see if it is blocked, and also verify whether the bypass valves are fully open.

Based on what you’ve described, the gas concentration and pressures in various areas are all within normal ranges. The temperatures in sections one, two, and three are also normal. As for section four, if there is no electric heater (you didn’t specify whether one is present at this temperature), then it is also basically normal. The problem is that the temperature at the inlet of the absorber is too high, at 230 degrees. This temperature is also the temperature in the outlet pipe after the first stage of conversion, which is usually between 160 and 190 degrees. Such a high temperature indicates that the heat generated during the first stage of conversion is not being effectively transferred to the system’s inlet temperature. Based on what you’ve described, secondary conversion requires 1–2 sets of electric furnaces, which indicates that the system has not reached thermal equilibrium. Given this situation, I believe you have already tried many different methods in terms of operation, so operational errors can be ruled out. In my opinion, it is very likely a problem with the design of the system’s heat exchanger. The first possible reason is that the heat exchange area of the exchanger is insufficient; the second reason could be that the shape of the heat exchanger is not appropriate, failing to meet the requirements for high gas flow speeds. The value of the heat transfer coefficient K is proportional to the gas flow speed – higher flow speeds result in a higher value for K, which in turn leads to better heat transfer. I suggest you check for the reasons from these two aspects. These are my personal opinions; please feel free to correct me.

It’s likely that the area for phase III exchange is insufficient; is it a scaled tube heat exchanger? Last edited by in the blink of an eye on 2009-3-8 10:37]

Is the inlet temperature at the three stages too high? How much was it designed for? It seems that the inlet temperatures at the three sections are a bit high; is the area for the second heat exchanger sufficient?

Thank you all! Our factory’s product is heat exchanger scaling tubes, manufactured by Zhanjiang Zhongming. It has been running for two years; I parked it last November, and it just started running again this year. It was working fine all along before that. The bypass valves and the II to IV switch were checked, and no issues were found. Yesterday, the electric furnace was turned off, and the inlet temperature at the four stages dropped to 388°C.

It is recommended to focus on checking the tube side of II during the next maintenance to see if there is any blockage. Also, what is the production capacity of the device? If it’s a small device, the issue with scaling tubes isn’t that serious.

Based on the description, the high inlet temperatures in section 3 and the low inlet temperatures in section 4 are likely due to problems with the heat exchangers and related bypass valves that are connected to the inlet temperatures of sections 3 and 4. As for the high inlet temperature of the absorption tower, it is likely related to the high outlet temperature of the third stage.

Judging from the inlet temperature of 230°C in the absorption tower, it seems to be high-temperature absorption; it’s just not clear what the temperature control is for the acid entering the tower If high-temperature absorption is not used, it should be a problem with the three exchanges. Zhanjiang Zhongming’s scaling tube? The results may not be very good; I once had 100 tubes break while using it.

It is recommended to conduct calculations for case 2 to check whether the heat transfer meets the requirements. For a gas concentration of 8.5, a temperature of 230 at the exit of the first stage should still be acceptable. The issue is that the secondary transformation has some problems. If switching to the second transducer reduces the temperature in section 3 by 20 degrees, then the temperature in section 4 should be able to increase by about 20 degrees. At the same time, optimize and adjust the inlet temperatures of stage 1 and stage 2; try to keep the inlet temperature of stage 1 around 430. This post was last edited by tangzhan on 2009-3-9 09:35.]

Thank you! Issue resolved: Prolonged parking (over two months) resulted in no thermal cleaning of the converter, which caused many rust particles from the upper part of the converter to clog the heat exchanger.

It’s the second time I’ve seen this situation you mentioned :)

The possibility of positive pressure blockage in the fan is low; it might be due to small areas for the third and second stage heat exchangers, or fouling that reduces the heat exchange efficiency

This is possible; during our annual overhauls, we always check the air chambers on the heat exchanger tubes coming from the converter to ensure that there are no rust deposits blocking those tubes.