In addition to the pressure and speed of water jet, the nozzle diameter is also an important factor that can affect the speed of water jet. The manufacturer of water cutting machine can say that the influence of these three factors on the speed of water jet can not be ignored, they directly affect its work efficiency. Therefore, in order to make better use of high-performance water cutting tools, we come to know how much the influence of nozzle diameter is.
Although the cutting speed and depth increase with the decrease of the nozzle outlet diameter, when the nozzle diameter is reduced under a certain pressure, the jet will atomize near the nozzle due to the air entrainment, which makes it lose the cutting ability. However, with the increase of nozzle diameter (from 0.1 mm to 0.4 mm), the cutting depth decreases. The outlet diameter of nozzle for cutting is recommended to be within 0.1L ~ 0.3mm. In addition, with the increase of nozzle diameter, the cutting speed and cutting depth decrease, but the width of cutting seam increases, that is, the amount of material damage per unit time increases. Under the same pressure condition, the quality of material cutting seam processed with 0.1 mm and 0.4 mm diameter nozzles is compared. It is also found that with the increase of nozzle diameter, the cutting seam becomes wider, the chip particle size becomes larger, and the quality (roughness) of cutting seam becomes worse. It can be considered that the total energy relationship of material crushing increases with the increase of jet power does not change. Although the jet power increases with the increase of jet pressure and nozzle diameter, the effect is quite different. The former obviously increases the cutting speed and depth, while the latter only increases the amount of material breakage, but decreases the cutting speed and depth. However, with the increase of the nozzle diameter, the contact area of the jet on the processed material increases, which increases the crushing resistance of the material, resulting in the decrease of the cutting speed and depth. Therefore, when the jet is used in cutting operation, increasing the jet pressure is an effective way to improve the operation efficiency. However, in terms of jet cleaning, derusting and stripping operations, the cutting depth is almost not considered, and the more important factor is the jet area. Therefore, when the jet pressure meets the cleaning requirements, increasing the nozzle diameter is more effective to improve the operation speed.
