Reasons for the high outlet temperature of the waste heat boiler
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In the production of methanol from coke oven gas, what are the possible reasons for the excessively high temperature at the outlet of the waste heat boiler? Could it be that the waste heat boiler is leaking?
Reasons for excessively high outlet temperature: 1. Excessively high temperature of the inlet air. 2. The level of waste boiler liquid is low. I think a leaking boiler won’t cause the temperature to rise too high.
Reply to 2# Ding Wei5411: It seems you’re referring to the steam from the drum!
If there is a leak in the waste heat boiler, the steam pressure will fluctuate; one can take a sample of the steam and analyze it to find out. It is possible to consider setting the liquid level in the waste heat boiler higher, or reducing the steam pressure; this also depends on the process gas coming in.
If the outlet temperature of the waste heat boiler is too high, the reasons could be: 1. A high temperature at the outlet of the synthesis tower, which leads to high pressure and temperature in the waste heat boiler; 2. A high temperature in the catalyst bed inside the synthesis tower; 3. An appropriate temperature at the inlet of the synthesis tower, along with high catalyst activity. The waste heat boiler should not leak water. If the waste boiler is leaking, it is sufficient to take a sample and analyze whether there is process gas present.
The high outlet temperature of the waste heat boiler is caused by scaling on the tube wall on the process gas side.
The waste boiler you mentioned is the one from conversion, right? In synthesis, the Ruchita method is generally used as it does not require a waste pot. If the outlet temperature of the gas produced from converting waste boilers is high, please check whether the steam pressure is too high Is the outlet temperature of the second-stage furnace still too high? Leaking from the waste boiler can only be due to a low temperature of the conversion gas.
Reply to 5# xnfh_wpzg: Hello, I’ve mentioned a few points; could you please tell me how to address the issue of overheating in the waste boiler?
1. High pressure in the waste boiler: Solution – Open the waste boiler bypass line to reduce the pressure.
2. High temperature at the outlet of the synthesis tower: Methods to lower the outlet temperature: 1. Reduce the amount of fresh gas; 2. Increase the amount of recycled gas; 3. Imbalance in the hydrogen-to-carbon ratio; 4. Increase the amount of wastewater discharged from the drum; 5. Increase the content of inert gas
2. High temperature at the outlet of the synthesis tower: Methods to lower the outlet temperature: 1. Reduce the amount of fresh gas; 2. Increase the amount of recycled gas; 3. Imbalance in the hydrogen-to-carbon ratio; 4. Increase the amount of wastewater discharged from the drum; 5. Increase the content of inert gas
I feel that the waste boiler is leaking, and the temperature at the outlet of the converted gas also rises; water has a higher specific heat, and the flow rate increases as well.
The reasons are as follows: 1. High exit temperature of the converter; 2. High steam pressure control; 3. Excessive amount of conversion gas; 4. Poor water quality, leading to scaling and poor heat exchange efficiency