Which one is better in sheet steel production or other sheet metal production? - A series of many small compressed air-operated flat nozzles, or one or more long compressed air-operated air knives? In reality, both have been used. Flat nozzles are smaller and typically provide greater blowing force. However, an air knife can increase its force by increasing its air gap, which usually provides enough force for the same application and has indeed been shown to do so. For this application, it usually means adding one or more spacers to increase the clearance.
The factors to consider are as follows:
Installation cost: The cost of using and installing multiple flat nozzles is usually higher than that of one or several long air knives.
Noise: A "good" air knife may be slightly less noisy and even have multiple spacers, making for a larger gap. But it depends on the number of gaskets used on the air knife and the flat nozzle.
Air consumption: The overall air consumption can be less depending on the set gap used by the air knife. This is very easy to calculate and determine.
Risk of damage: If the air knife is damaged, the cost of replacement will exceed the cost of replacing a single or even several flat nozzles. If the risk of damage and replacement is high, then the decision to flatten the nozzle will be affected. If the risk is lower, then an air knife will be a better option.
Weighing the importance of these factors in any given situation will lead to the best choice for a particular location.