January 28, 2022

Classification of water mist nozzles

1. Hedging type water mist nozzle: atomization is carried out by two high-speed liquid jets colliding with each other or a high-speed jet colliding with a metal plate.​

2. Vibrating water mist nozzle: through the action of sound waves and ultrasonic waves, the liquid is vibrated and destabilized, and the nozzle types that are split and atomized and broken into small droplets are collectively referred to as vibrating atomizing nozzles. There are low-frequency mechanical vibration atomizing nozzles, ultrasonic vibration atomizing nozzles, etc. Due to the complexity of the device, it is usually only used in the laboratory and terrestrial industry.​

3. Bubble atomizing nozzle: By setting an air flow pipe before the outlet of the nozzle, the head of the pipe has a certain number of small holes, the gas enters the liquid field at a very low speed under very low pressure, and the gas-hydraulic pressure difference is only So that the liquid does not flow back into the trachea, when the liquid flows through the nozzle, it is squeezed into a film or small fragments by the bubbles, and the small bubbles burst out of the nozzle. droplets.

4. Electrostatic atomization nozzle: by applying high-voltage static electricity to the liquid, the droplets are charged in the electric field. The repulsion between the charges expands the surface area of ​​the liquid film, and the surface tension of the liquid tends to reduce the surface area. When the inter-repulsion force is greater than the surface tension, the liquid film is broken into small droplets. The advantage of electrostatic atomization nozzle is that the atomization effect is very good, but its flow rate is very small, so it is only suitable for spraying and printing.

5. Pressure water mist nozzle: by converting pressure into fluid kinetic energy to form a high-speed moving liquid column jet or liquid film jet, which meets the surrounding low-speed gas medium, the liquid column or liquid film is in the crushing force and anti-breaking force. Broken under the action, and finally complete the atomization. Pressure water mist nozzles mainly include single centrifugal nozzles and direct current nozzles.​​

There are two types of typical centrifugal sprinklers. One is a centrifugal nozzle with a vortexer. The liquid enters the spiral groove and moves downwards in a spiral line while rotating. After leaving the nozzle, the liquid micelle is no longer constrained by the inner wall, so it moves along the axis and tangential direction to form a vortex. A tapered membrane. The other is a centrifugal nozzle with a tangential inlet. The liquid enters the centrifugal chamber through a tangential hole on the nozzle housing, and is then ejected from the orifice.​​

Under the action of the pressure difference of the direct-flow nozzle, the spray liquid is ejected through the nozzle and atomized under the action of hydrodynamic force and surface tension. The diameter of the nozzle of the DC nozzle is generally 2-4mm. If the diameter is too small, it is easy to block; when the diameter is too large, the atomization effect is very poor.​

6. Pneumatic water mist nozzle: Pneumatic type is also called medium type, which atomizes the sprayed liquid by using air or steam as the atomizing medium. The working principle of the pneumatic water mist nozzle is to use the kinetic energy of the flowing gas to blow away the liquid column or liquid film and break it into droplets.​

7. Rotary water mist nozzle: The rotary type is also called the rotary cup type. By injecting the liquid on the surface of a high-speed rotating cup or circular plate, the liquid is evenly thrown out by the centrifugal force generated by the high-speed rotation of the rotary cup. The film is broken and the atomization process is completed. The rotary water mist nozzle has the characteristics of low price and simple structure.