Development of water jet technology

It is worth noting that in the 1960s, it was in the initial stage dominated by low-pressure water jet mining. At the same time, the development of high-pressure intensifier pump and high-pressure pipe fittings (collectively referred to as high-pressure equipment) with the main purpose of static pressure test and chemical process achieved many commercialized achievements (their medium is mainly not water), which laid the foundation for the arrival of high-pressure water jet technology;

In fact, the industrial test of water jet was mainly carried out for shearers and cleaners in the 1970s. It is worth noting that the main direction of this period is to improve the pressure and reliability of high-pressure dynamic equipment with water as the medium, and develop various forms of jet. In fact, the history of water jet cutter began especially in 1972. During this period, it belongs to the international water jet technology conference hosted by British fluid machinery research group. The biennial major American water jet technology conference hosted by the American Water Jet Technology Association (wjta) since 1981 and the Biennial International Water Jet Technology Conference in the Asia Pacific region hosted by the international water jet Association (iswjt) and the Japanese water jet Association (jswjt) since 1990 have greatly promoted the exchanges and development of the global water jet community.

By the 1980s, this stage was a period of rapid development of high-pressure water jet technology. It is worth noting that the field of water jet in this period is prominently reflected in the trend of high-pressure and ultra-high pressure, large-scale and integrated manufacturing power, more specialization and new and special-shaped water jet forms have become more products, large-scale and commercialized, especially the more reliable application of cleaning, derusting and cutting, Security has also been provided and rapidly extended to various industrial sectors. Since the 1980s, the expansion of the application fields of abrasive water jet, cavitating jet and air-water jet, including the further development and extension of rotating jet, has pushed the high-pressure and ultra-high-pressure water jet technology to a new stage and height.

In the 1990s, some difficult research, such as multi-dimensional water jet cutting of robots, underwater cutting operation, well nozzle cutting, and dry ice cutting, also included the theme of international conferences, which basically focused on water jet cutting. Enriching and improving the research and application of water cutting has become the focus and hotspot of the international water jet industry, It is worth noting that standards and technical monographs in this field also appear from time to time.

In recent years, it can be seen from various innovative achievements on water jet, in a new era that can freely control the characteristics of various types of high-pressure water jet technology according to actual needs and benefit mankind, water jet technology has become a special comprehensive new discipline.

Water jet is a beam of high-speed water jet emitted from a small diameter hole, which acts on the material and can clean, peel and cut the material with sufficient energy. This performance of liquid encourages researchers from various countries to explore a new way of "water operation" and turn the kinetic energy of water jet into mechanical energy to remove materials.

Water jet is a high-speed flow beam with different shapes formed by the outflow of the nozzle. The flow rate of the jet depends on the pressure drop before and after the nozzle outlet section.

Water jet is the simplest form of energy transformation and application. Usually, the power driven pump completes a process of suction and discharge of water, and sends a certain amount of water pump to the high-pressure pipeline to make it reach the nozzle with a certain energy. The aperture of the nozzle is required to be much smaller than the diameter of the high-pressure pipeline. Therefore, if a certain amount of water reaching the nozzle wants to flow out of the nozzle aperture, it must be accelerated. In fact, the water accelerated and condensed through the nozzle hole forms a jet. When the ejected jet hits the surface of the target (workpiece), it is called jet operation.

Once the jet leaves the nozzle, its condensation section will not be too long. In this regard, the velocity of jet is particularly important. The water is pumped to obtain pressure, which first drives the water from the pump to the nozzle and then makes it pass through the nozzle at a given speed. During this period, the friction between the water flow and the pipe wall forms the main pressure loss. At the same time, the water also forms the pressure loss with its turbulence because it passes through different shape flow channels.