There are many kinds of atomizing nozzles, so how many kinds can they be classified according to the atomization method?
(1) Mechanical atomization
Mechanical atomization mainly depends on the high-speed jet generated by the liquid under the action of pressure difference to atomize itself. Therefore, it can be divided into direct nozzle, centrifugal nozzle and rotary nozzle.
Direct atomization and centrifugal atomization can be collectively referred to as pressure atomization. The direct spray nozzle mainly relies on the spray of water to achieve the purpose of atomization. The requirement of water pressure is relatively high, and the larger the diameter of the spray hole is, the coarser the atomization is. Therefore, the diameter of the spray hole cannot be too large and the flow regulation range is relatively small. Centrifugal nozzle uses the centrifugal force generated by high-pressure water through the cyclone device to produce liquid film, which is broken by air and atomized. The effect of centrifugal atomization is better than that of direct atomization, but it also needs higher water supply pressure, so the application conditions are limited.
Rotary nozzles are generally divided into rotary type and rotary nozzle type. The rotary type is divided into rotary cup type and rotary disc type. The rotary cup atomization is to spray water into the front end of the conical rotor, and to turn the water into a thin film by means of a high-speed rotating cup, and atomizing the liquid by the combined action of "centrifugal spray" and "velocity spray". Similarly, disc atomization relies on the high-speed rotating disc to atomize the liquid.
(2) Medium atomization
According to different atomization methods, it can be divided into pneumatic atomization and bubble atomization. Pneumatic atomization nozzle is widely used.
The pneumatic atomizer relies on a certain pressure of gas (compressed air or steam) to form a high-speed air flow, so that a high relative speed is formed between air and water to achieve the purpose of atomization. Its advantage is that it can obtain good atomization effect under low water pressure, and the working condition can be adjusted in a large range. However, the power source is not single and the system composition is complex.
(3) Special nozzle atomization
Special nozzles generally adopt the principles of ultrasonic, electromagnetic field and electrostatic action for atomization. Although this kind of nozzle has good effect in some other industrial applications, it is rarely used due to the bad underground environment of coal mine.
