Hydrorefining heating furnace

The excess air coefficient is too high; try adjusting the blower dampers and the dampers of each burner.

A 10% oxygen content corresponds to an excess air factor of around 1.2, which is indeed very high! ! ! !

A high excess air coefficient results in low thermal efficiency of the heating furnace; it is generally appropriate to keep it between 1.5% and 3%. To address this situation, first check the sealing condition of the furnace body, and then adjust the air supply volume based on the burning conditions of each burner.

1 Carefully check whether there is any air leakage in the three doors and one panel. Double-check the zirconia tip. 3 Check the composition of the fuel.

The air excess coefficient is high, resulting in significant air leakage; the chimney dampers are adjusted to control the negative pressure at 3–5 mmH2O, and the dampers of the fans or burners are adjusted as well.

First, determine whether zirconia is effective and reliable in use. If it is effective, then an oxygen content of 10% is too high. The main reasons for a high oxygen content in the flue gas are as follows: 1. The \"three doors and one plate\" mechanism isn’t adjusted properly； 2. Check whether there is any air leakage from the furnace body. Impact of high flue gas oxygen content on the heating furnace: More air enters the furnace chamber, taking away some heat. The main effects are a high air excess coefficient, increased flue gas losses, reduced furnace efficiency, and increased fuel consumption.

A high oxygen content can also lead to excessive oxidation of the furnace tubes; at an oxygen content of 10%, the excess air coefficient is approximately 1.8. Furnace negative pressure indicates the suction force within the furnace; if a positive pressure is indicated, it can lead to unstable combustion, gas leakage, and damage to the external structural components. By maintaining an appropriate level of negative pressure in the furnace during operation, heat can be concentrated inside. However, if the negative pressure is too high, excessive air will leak out, resulting in the waste you mentioned. This post was last edited by rqm200507 on 2008-4-28 18:48.]

The O2 content reaches 10%, which is very, very high. 1. The O2 level in the gas used for heating the hydrogenation refining furnace should be controlled at 2–4%, while that in the oil used should be controlled at 2–5% ； 2. Regularly inspect the zirconia; it is installed on the top of the radiation chamber and requires periodic inspection ； 3. Manual sampling for O2 analysis, compared with zirconia analysis ； 4. Properly control the \"three doors and one panel\" to maintain a negative pressure of 10~20 Pa in the roof of the radiation chamber ； 5. Regularly check the combustion condition of the burner to determine its performance.

Excess air factor = (100 – yCO2 – yO2) / (100 – yCO2 – 4.76yO2), where yCO2 and yO2 represent the volume percentages in the flue gas. The desired range for this value varies depending on the type of furnace; for cylindrical furnaces, it should be maintained between 1.15 and 1.20

What kind of refractory material is used in this furnace?

I know that in most hydrogenation refining reactors, the oxygen content is on the high side; it’s common for it to be above 10%. I’ve heard that Qi Lu Petrochemical has managed to reduce the oxygen content in its reactors recently, but I haven’t had the chance to see it for myself. Could any of you tell me how to lower the oxygen content?

Excess air factor: The amount of air required to burn 1 kilogram of fuel is calculated using the following formula: Theoretical air volume = 100/23.2 * (2.67C + 8H + S)/100. In practice, to ensure complete and proper combustion of the fuel, the amount of air supplied to the furnace must be greater than the theoretical amount. This is because the mixing of air and fuel cannot be made completely perfect. The ratio of the actual air volume entering the furnace to the theoretical air volume is the excess air coefficient a = L/L0, where L and L0 represent the actual air volume and the theoretical air volume, respectively, in kg/kg of fuel. The excess air coefficient is an important operational parameter for heating furnaces; it has a significant impact on the overall thermal efficiency of the furnace, and is directly related to the fuel consumption and economic efficiency of the heating furnace. When the excess air coefficient is low, insufficient air is supplied, resulting in incomplete combustion of the fuel; in severe cases, black smoke is emitted, which leads to fuel waste and a decrease in the furnace’s thermal efficiency ； When the excess coefficient is too high, a large amount of cold air enters the furnace, leading to many adverse consequences: (1) The flame temperature drops, reducing radiant heat transfer. (2) An increase in flue gas volume leads to more heat being carried away by the flue gas, resulting in a decrease in the overall thermal efficiency of the furnace, increased fuel consumption, and higher operating costs. (3) An increase in the oxygen content in the flue gas exacerbates oxidation on the surface of the furnace tubes. (4) The increased amount of SO3 generated by the decomposition of fuel gas with high sulfur content exacerbates tube corrosion and ash deposition. Therefore, while ensuring complete combustion of the fuel, the excess air coefficient should be reduced as much as possible. Factors affecting the excess air coefficient include: fuel properties, burner performance, furnace sealing, and measurement and control capabilities ； Operational level.

It’s too high; generally, 1.5–3% is more appropriate. Too high a temperature can cause corrosion to the furnace, and the flue gases carry away a large amount of heat, which is not conducive to extracting heat from the material

The simplest method for calculating the excess air coefficient is: 21/(21-O2). Here, 21 represents the oxygen content of 21% in the air entering the furnace; O2 is the value measured by a zirconia oxygen analyzer, which indicates the remaining oxygen content after combustion, while 21-O2 represents the actual amount of oxygen required. The excess air coefficient is the theoretical oxygen demand divided by the actual oxygen demand. 21/21-10=1.9