Problems with burner cooling water
Thread Content
The burner cooling water coil is a cooling coil that surrounds the end of the burner; it is used primarily to lower the temperature at that end of the burner and prevent it from being damaged by high-temperature gases. However, based on actual data, the temperature difference between the water entering and leaving the burner is very small. In our factory, the inlet water temperature is 42 degrees, while the outlet water temperature is around 50 degrees. Moreover, the flow rate isn’t very high either, approximately 20 cubic meters per unit time! Based on these data, the amount of heat carried away by the burner cooling water is quite limited. The temperature of the process gas at the burner located at the top of the furnace is very high; it’s probably around 800 to 900 degrees at least. I’ve checked that hydrogen has a higher heat capacity than water. How does the burner cooling water manage to protect the burner? Is it because the area of contact between the burner and the process gas is very small? I hope everyone can offer some guidance; it would be great if a heat balance calculation could be provided
First: The material exiting the burner is at a cold state, and the temperature at the burner tip is not as high as that in the reaction zone. Second: The purpose of the burner cooling water is mainly to prevent heat from building up and to carry away that heat.
It has cooling water, just like yours. However, the inlet water temperature is 40, and the outlet water temperature is around 45
There is a dark area at the burner, so the temperature at the head of the burner isn’t that high. Moreover, the design developed by the design institute is based on thorough calculations, with a margin for safety; as long as the cooling water and the burner are functioning properly, even a temperature of 1400 degrees won’t damage the nozzle
Reply to 4# hongtao915: Judging from the current usage of the burners, that is indeed the case. However, I don’t quite understand how it is possible for the limited heat carried away by the burner’s cooling water to still provide effective protection for the burner. Is it because the heat level at the end of the burner inside the furnace itself isn’t high, or is it due to a low heat transfer coefficient between the process gas inside the furnace and the cooling water coils? Some people also say it is because the oxygen and water-coal slurry entering the burner are at room temperature; after being preheated by the process gas inside the burner, they enter further. Thus, it is the water-coal slurry and oxygen that carry heat into the furnace. I wonder if this explanation is valid? I personally believe that the increase in temperature of water-coal slurry after injection is limited; this view seems inappropriate. I hope everyone can offer some guidance
What the original poster is describing is quite normal; there’s nothing difficult to understand about it! The heat loss in the gasifier must not be too high; the insulation material placed behind the refractory materials serves to prevent heat from escaping. Heat transfer is isotropic; the fire-facing surface of the nozzle occupies a very small portion of the inner surface of the vaporization furnace, so it is impossible for it to transfer much heat. Don’t waste too much effort on this!
Cooling water is used to protect the burner head. In fact, 48° is already a relatively high value; generally, the temperature at the outlet is around 45°, with a variation of 2°. Jinan Tongzhi Innovation Technology specializes in manufacturing burners, and you can consult them for more details
The burner has only a small surface area, so whether it’s heat conduction, radiation heat transfer, or some other mechanism, the amount of heat accumulated in this area is not large. As long as cooling water is used to continuously remove that heat, the temperature will not rise above safe levels.
In our case as well, there is basically no temperature difference between the feedwater and return water – around 30 degrees. With a single nozzle and 90 cubic meters of slurry per unit time, there should be a mixing zone, and the temperature in that mixing zone must also be quite high! I hope some expert can answer and provide guidance
In our case as well, there is basically no temperature difference between the feedwater and return water – around 30 degrees. With a single nozzle and 90 cubic meters of slurry per unit time, there should be a mixing zone, and the temperature in that mixing zone must also be quite high! Looking forward to your guidance