Problems with combustion in melting furnaces
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The blower of our plant’s melting furnace (regenerative combustion melting furnace) is equipped with an inverter. Recently, an abnormal phenomenon was observed: measurements of the flue gas composition showed that when burner No. 1 was in use, the CO content in the flue gas was very high (over 10,000 ppm), and black smoke appeared, indicating incomplete combustion； However, when burner #2 is in operation, there is no CO, and the oxygen content is relatively high (around 8%), making the combustion flame appear to burn well! Question 1: With the same blower and the same opening degree, the frequency of inverter 1# is higher (1#: 37 Hz, 2#: 32 Hz). Why is there insufficient combustion air when burner 1# is in use, while burner 2# has excessive combustion air? Note: The natural gas flow rate for the two burners is slightly higher for burner #2. Question 2: It was observed that when burner #1 was in operation, the current drawn by the blower was low; at a set frequency of 37 Hz, the current was only 15 A. In contrast, when burner #2 was operating, with a set frequency of 32 Hz, the current was 20 A. We suspect that either the auxiliary combustion butterfly valve for burner #2 or the exhaust butterfly valve for burner #1 is not fully closed, and thus has not returned to its proper position ； Secondly, the blockage of the regenerative material in #1 results in insufficient air flow and a decrease in current. Ask which of the two judgments is reasonable or if there are other reasons?
Although I don’t know much about this, the question is quite detailed, the description is thorough, and it’s also very professional. I hope that when asking questions, people will try to describe the problem in as much detail as possible, as this will help others analyze it.
Your smoke composition? Smoke exhaust issue? Temperature inside the furnace? Mechanical problems are less likely. The problem with the heat storage material might be more serious. The CO content in the flue gas is very high (over 10,000 ppm); actually, it’s not that high! A relatively high oxygen content (around 8%) is the main factor that leads to increased energy consumption! The potential is indeed huge! Feel free to ask! 13601145688@139.com
The melting furnaces in our factory use natural gas; the CO content in the exhaust gases is very high (over 10,000 ppm). The exact value is unknown, but it exceeds the measurement range of the instruments. Under normal conditions, the CO content according to the theory of complete combustion should be 0; the presence of CO in the flue gases indicates that the fuel has not burned completely, and slight black smoke in the flue gases also proves that the fuel has not burned fully. My question is: With the same blower and the same opening degree, the current is lower at higher burner frequencies, which indicates that the load on the blower decreases when another burner is burning. What causes this?