Devices for spraying liquids

Various types of sprayers and pneumatic nozzles which allow us to produce finely dispersed gas-liquid jets and aerosols with drops 500-10 pm in diameter are used to create coatings. Two ways of producing finely dispersed jets are known  

Aerosols and mists are formed when liquids are sprayed using compressed gas However this increases the proportion of waste liquid. In order to eliminate waste, a porous diaphragm resembling a cut-off cone is used. Its smaller base borders the face between the nozzle for the liquid and holes for the gas the larger base is connected to the spraying head and forms chambers connected via holes to create a peripheral enclosing air stream. 4 

The spraying device works in the following way. The prepared liquid mixture of reactive components flows to channel 3 through pipeline 4, and is distributed in a circular direction by the rotation of core 2. This movement simultaneously reduces the apparent viscosity of the liquid. Then the liquid goes to the ring nozzle 5. Porous rings 6 and 7 are placed on the external and internal surfaces of nozzle 5 at a distance of (1 - 20)h from the exit (where h is the distance between the 

A sharp decrease in wall friction in the flow of visco-elastic liquids (including chemically reactive liquids) leads to the formation of low pressure zones. The gas flows into these zones, which leads to disruption of the liquid stream in nozzle 5. Additional gas blown into the disrupted liquid stream through the ring gaps by pipelines 11 and 15 causes separation of the liquid into smaller droplets, thus improving spray dispersion. 

The porous rings are positioned at a distance of (1 - 20)h from any exit, because if they are positioned any closer, stream rupture inside the channel cannot be guaranteed. If they were placed at a further distance, the disrupted stream reforms into a compact stream further along the channel, which would prevent proper dispersion of the spray jet. 

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