The Key Component of New Carbide Drill Bits—Carbide Nozzles

The nozzle is the key component of the new carbide drill bit, and its performance directly determines the rock-breaking efficiency of the drill bit. Because the nozzle is installed inside the new cemented carbide drill bit and its length and outside diameter are limited, the existing industrial nozzle design standards are only suitable for conditions that are not limited, so the nozzle must be designed to produce the best punching effect of the jet. Under the special engineering background of limited nozzle size, nozzle design is required to meet the following requirements:

① The greater the impact force of the jet is required, the better, so that the hard rock can be broken. At the same time, it is also required that the jet stream be as dense as possible, which can effectively avoid the interference of the leading drill bit on the jet stream. The density of the jet means that after the jet leaves the nozzle, the convergence is better and the diffusion angle of the jet is smaller. But at the same time, it is also required that the aperture of the jet erosion is large enough, so that the rock can be pre-broken for the leading bit, and the force of the tool can be reduced to a greater extent.

The basic shape of the jet after it leaves the nozzle: it mainly includes the initial section and the basic section, and there is a dissipation section after the basic section, but the jet in this section has broken into water droplets. There is a conical iso-kinetic flow core region in the initial section, which still maintains the initial injection velocity. Each section has different functions in practical engineering applications, the initial section is suitable for material cutting and crushing, the basic section is suitable for surface processing, cleaning, rust removal, etc., and the dissipation section is mainly used for cooling and dust removal. In this study, the core segment of the jet is mainly used to break rocks. Therefore, the nozzle design should make the core segment of the jet as long as possible, which can make the jet have stronger erosion ability at a longer distance. The longer iso-velocity core enables the abrasive to continue to accelerate after leaving the nozzle, thus improving the speed of abrasive particles. The density of the jet is mainly related to the contraction angle of the nozzle, and the appropriate nozzle contraction angle should be selected in the design of the nozzle.

②To ensure that the life of the nozzle can meet the engineering requirements. Through reasonable structural design and material selection, the service life of the nozzle is matched with the life of the drill, and at the same time, the economy is considered, and the materials that meet the requirements are selected based on reasonable prices.

② The nozzle is a liquid solid two-phase high-speed flow, the nozzle wears quickly, so the material of the nozzle has higher requirements, the nozzle should have mechanical strength and good wear resistance and corrosion resistance. At present, tungsten carbide, diamond, and artificial gemstone materials are commonly used. The hardness of the cemented carbide nozzle can reach HRC93, the compressive strength can reach 6000MPa, and it has strong wear resistance. Tungsten carbide nozzles are made by powder metallurgy method, and the nozzles are molded by steel die.

③ Diamond hardness is very high, Mohs hardness of 10, and anti-cavitation damage ability, life is longer than tungsten carbide, but because of the hard texture, polishing accuracy is low, the quality of the jet is similar to the tungsten carbide nozzle, the price is much more expensive, considering the economy can give up this material. There are many kinds of artificial gems, such as sapphires, rubies, and so on. High hardness, and strong resistance to water jet abrasion, but it is a brittle material, easy to break. Combining the quality of jet nozzles, processing difficulty, price, and cost, our company uses tungsten carbide material to manufacture nozzles.

ZZBETTER produces various kinds of carbide nozzles, which can meet the requirements of our customers who are from different industries and fields. We can also manufacture non-standard ones as well as other tungsten carbide products. Welcome to visit our website if you are interested：www.zzbetter.com. And this is my email：[email protected]