When designing nozzles, what should be the exit velocity of the gas at the nozzle outlet? What is the purpose of the openings around the nozzle cone section?
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I have a question: when designing nozzles, what is the typical exit velocity of gas at the nozzle outlet? One more question: I saw a nozzle diagram where the diameter of the inlet pipe is DN150, and the inner diameter at the outlet of the nozzle cone is approximately 30. There are also several openings around the cone; what is the function of these openings? According to Bernoulli’s equation, as the flow velocity increases in the conical section and the pressure decreases, gas should not be ejected from these small holes; instead, air from the outside will enter. Is it this effect?
Personally, I think what the original poster said isn’t quite accurate; the small hole in the cone is likely used for spraying coal gas outward, as the end of a cone is usually closed. As for the flow rate, it is calculated based on the type of gas, its properties, etc ； For example, phenomena such as fire separation and tempering must not occur. The principle behind this is to ensure that the gas is mixed as evenly as possible with air