Introduction The nozzle is part of the pre-painting equipment and is the heart of the spray system. The spray treatment method is one of the common methods used in the pre-coating process. The process is to spray the bath liquid onto the surface of the workpiece with a water pump, and accelerate the chemical action by mechanical scouring to complete the degreasing, derusting, surface conditioning and phosphating. And passivation and other processes, the degreasing effect is better, the phosphate film is more uniform, the processing time is shorter, and the production efficiency is higher. For different workpieces, when selecting the nozzle type, there are many factors that need to be considered comprehensively. The correct selection can give full play to the performance of the pre-painting agent and its own characteristics, and obtain high-quality pretreatment effect. 2 Nozzle characteristics Since the nozzle is designed to work under a variety of different spray conditions, the nozzles that are suitable for the application are selected to achieve the desired spray performance in use. The characteristics of the nozzle are mainly reflected in the type of spray of the nozzle, that is, the shape formed when the liquid leaves the nozzle opening and its running performance. The name of the nozzle is divided into a fan shape, a cone shape, a liquid column flow (ie, a jet), an air atomization, and a flat nozzle. The cone nozzle is divided into two types: a hollow cone and a solid cone; The nozzles (ie, mixing nozzles), the strong (hot) tuyere blowing nozzles, and the special nozzles (such as garden nozzles, cylinder washing nozzles, tube cleaning nozzles, etc.) are named after the nozzle performance. 3 There are many types of nozzles for selecting nozzles, and the range of options is large. Generally speaking, nozzles for degreasing and water washing processes can be selected with jet nozzles with strong impact force: taking "V" type fan nozzle as an example. The spray angle is preferably 60, which has a large impact force; and the nozzle of the phosphating process can use a centrifugal nozzle with good atomization, fine and uniform water particles and weak impact force: the "Z" type cone For example, the nozzle is preferably a distance of 40 cm to 50 cm from the workpiece, and has a spray effect of dispersing and atomizing the liquid. The arrangement of the nozzles on the nozzle can be in the form of parallel and cross, and the channel type adopts vertical cross arrangement, and the spraying effect is better. The factors that select the nozzle are flow, pressure, spray angle, coverage, impact force, temperature, material, application, etc., and these factors are often intertwined and mutually constrained. Flow and pressure, spray angle and coverage are proportional. The purpose of any nozzle injection is to maintain continuous contact of the bath with the workpiece. This factor 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, as well as the choice of material. The material of the nozzle should also be determined according to the chemical characteristics of the bath. For non-corrosive baths, bronze casting or plastic die casting can be used according to the difficulty of processing. In order to prevent corrosion, non-metallic materials may be used; for strong etching baths such as sulfuric acid and hydrochloric acid, nylon plastic may be used; nozzle materials for phosphating baths are generally made of acid-resistant stainless steel, and nozzles for preventing corrosion may also be directly selected from stainless steel or Made of nylon material. Nozzles with a certain impact force should use small-angle nozzles, which are better for liquid column flow (ie jet); fan nozzles are suitable for cleaning, degreasing, cooling, etc. Conical nozzles are suitable for drifting, surface layer, phosphating, humidifying In the aspect of dust removal, etc.; the venturi mixing nozzle should be installed in the paint storage tank and the tank body. Take the "H" type stirring nozzle (also known as the venturi nozzle) as an example. The bath liquid is sucked through a certain pressure and the approach channel. The liquid is mixed and sprayed together at a flow rate of 1:4, and the effect of the solute without air mixing is achieved, thereby preventing precipitation, because the agitation ensures uniform mixing of the chemical solution. 4 nozzles are arranged in a certain arrangement according to the outer dimensions of the workpiece to install a number of nozzles, surrounded by the workpiece, so that when the workpiece passes through the spray zone, all surfaces can be sprayed by the bath, the entire spray The nozzles should be evenly arranged to ensure the process time and effect of the spray washing. The distance between the nozzle and the workpiece should be within the range of the jet diffusion, so the nozzle and nozzle arrangement should be reasonable. The distance between the nozzle and the nozzle is 250mm to 300mm. When the cross is arranged, the distance between the nozzle and the workpiece is not less than 250mm. The immersion pre-treatment agitator consists of a pump to the pipe to the agitation nozzle to form a complete tank injection system. The stirring nozzle uses the venturi principle, the bath liquid enters the pipeline under the action of a certain pressure, forms a high-speed jet through the nozzle hole of the stirring nozzle, and generates a low-pressure zone at the approach port around the nozzle to form a siphon phenomenon, and the bath liquid under the action of the pressure difference It is sucked into the stirring nozzle so that a large amount of liquid can be circulated. The distance between the stirring nozzle and the bottom of the groove is 25mm to 75mm, and the distance from the workpiece is 200mm to 380mm. The angle of the nozzle should be determined according to the size of the workpiece. When the width of the workpiece is small, the nozzle hole can be designed to be vertically upward. When the workpiece is large, the nozzle hole can be designed to be 35 to 45 with the vertical surface; when the workpiece width is large, the nozzle hole can be designed to vertically downward when the workpiece width is large. However, this condition will stir up the sediment and therefore only apply to the agitation of the sediment-free bath. 5 nozzle quality inspection and common causes of damage Nozzles need to be repaired, regularly inspected, cleaned or even replaced to ensure the quality of the final product and to maintain the economic benefits of the production process. The manner and frequency of maintenance procedures depends on the application. Maintenance plans can be arranged based on usage, liquid and nozzle material. There are seven common causes of nozzle spray problems: a) Corrosion and wear: The material on the nozzle nozzle and the surface of the inner flow passage gradually becomes larger or deformed, which in turn affects flow, pressure and spray shape. b) Corrosion: The chemical action of the spray liquid or the environment causes corrosion to damage the nozzle material. c) Blockage: Dirt or other impurities in the liquid block the nozzle mouth, thus limiting the flow of the nozzle and disturbing the spray shape and its uniformity. d) Bonding: Splash, mist or chemical build-up on the inside or outside material of the edge of the nozzle by evaporation of the liquid, leaving a dry solidified layer, blocking the nozzle opening or internal flow path. e) Temperature damage: Overheating can have a certain detrimental effect on nozzle materials designed for non-high temperature applications. f) Improper installation: A washer that deviates from the shaft, excessive tightening or other problems that change position can have an adverse effect. g) Accidental damage: In the installation and cleaning, the nozzle may be accidentally damaged due to the use of incorrect tools. 6 nozzle application areas 1, all kinds of cleaning machines in the automotive industry, spray cleaning in the coating line, atomization spray, tank mixing and other equipment. 2. Various types of washing machines and painting lines in motorcycles, bicycles, refrigerators, washing machines, etc. 3. Various cleaning equipment in the mechanical processing industry. 4. Humidification devices in the light industry textile industry. 5. The nozzles of the washing machine manufacturer and the painting equipment manufacturer. 6. Nozzles for agricultural sprinkler irrigation and urban greening. 7 Conclusion Whether it is engaged in project design selection nozzles or user procurement nozzles, we hope to find a professional manufacturer with complete specifications, stable product quality and timely delivery. Our company is a professional manufacturer specializing in the production of industrial nozzles, powder filters and air filters. Welcome customers.