Since the nozzle is designed to work under a variety of different spray conditions, the nozzle that suits the needs is selected to achieve the best spray performance in use. The characteristics of the nozzle are mainly reflected in the spray type of the nozzle, that is, the shape of the liquid when it leaves the nozzle and its running performance. The name of the nozzle is that the spray shape is divided into fan, cone, liquid column flow (ie jet), air atomization, and flat nozzle. The cone nozzle is divided into two categories: hollow cone and solid cone;
The factors for selecting nozzles include flow rate, pressure, spray angle, coverage, impact force, temperature, material, application, etc., and these factors are often interrelated and restrict each other. Flow rate and pressure, spray angle and coverage are all proportional to the relationship. The purpose of any nozzle spray is to maintain continuous contact between the bath liquid and the workpiece, and the factor of flow rate is more important than pressure. The temperature of the liquid does not affect the spray performance of the nozzle, but it affects the viscosity and specific gravity, and also affects the choice of materials.
Selection of nozzle material
The material of the nozzle should also be determined according to the chemical characteristics of the bath:
1. For non-corrosive baths, bronze casting or plastic die casting can be used according to the difficulty of processing;
2. To prevent corrosion, non-metallic materials can be used;
3. Nylon plastic can be used for strong corrosive baths such as sulfuric acid and hydrochloric acid;
4. The nozzle material used for the phosphating bath is generally acid-resistant stainless steel;
5. The nozzle to prevent corrosion can also be directly made of stainless steel or nylon.
Nozzle selection method
For nozzles with a certain impact force, small-angle nozzles should be selected, and liquid column flow (ie jet flow) is the best;
Fan-shaped nozzles are suitable for cleaning, degreasing, cooling, etc., cone-shaped nozzles are suitable for rinsing, surface layer, phosphating, humidification, dust removal, etc.;
For the nozzles of degreasing and washing processes, the jet nozzle with stronger impact force can be selected: Take the “V” type or fan nozzle as an example, the spray angle is 60° as the best, which has a larger impact force;
For the nozzle of the phosphating process, a centrifugal nozzle with good atomization, fine and uniform water particles, and weak impact force can be selected: Take the “Z” type or cone nozzle as an example, the best distance between the nozzle and the workpiece is 40cm-50cm, It has the spray effect of dispersing and atomizing the liquid.