Abrasive Jet Processing System Based On Gas-liquid-solid Mixing And Experimental Study

Mechanical seal is an important method to solve the leakage problem of rotating mechanical dynamic seal.The service life and reliability of seal face directly affect its safety and stability.At present,one of the main development directions of mechanical seal is to find a way to solve the problem of friction and wear between the face of seal under the condition that the leakage quantity is up to standard,and finally to realize the goal of long service life.The sealing face of the ordinary mechanical seal is in direct contact with each other,and there are serious problems such as wear and heat dissipation,which limit its use and development.A large number of studies have found that the non-contact mechanical seals with array micro-pits and micro-grooves are machined on the end surfaces of mechanical seals,including the new technology of mechanical seal represented by gas film seal,liquid film seal and macrotexture of the end face,which can reduce friction.Easy to dissipate heat and store lubrication and so on.However,many mechanical sealing materials,including brittle materials such as cemented carbide and silicon carbide,are difficult to process using conventional methods.Based on the micro abrasive air jet machining technology,this paper presents an improved air jet processing technology,which allows various abrasive slurry to enter the mixing chamber to replace the usual air and dry abrasive.Gas-liquid-solid three-phase mixing micro-abrasive jet processing technology for mechanical seal end texture processing.1.In this paper,the method of micro-texture on the mating face of cemented carbide mechanical seal by multi-phase jet machining with micro-abrasive was put forward,and the abrasive circulation system of the original machining device and the clamping fixture for the whole ring were optimized.Finally,the precision micro-abrasive multi-phase jet machining device accelerates the abrasive solution to form a continuous and stable multi-phase jet through compressed air under the condition of low pressure and strong strength.The abrasive circulation system can realize the continuous use of abrasive.The processing cost is reduced;According to the structural characteristics of the seal ring,a set of clamps suitable for different diameter rings were designed,which is convenient for one-time clamping.2.Considering the high divergence of air-driven jet and the requirement of different texture size,the edges of the desired features were defined using masks of 304 stainless steel sheet via laser machining in the machining process.Then the basic parameters of this jet machining as well as maskgeometry effects on the frosted regions,the channel width and the channel depth are studied through experiments.The channels machined using wax spread between the mask and the workpiece are slightly eroded on the edges with frosted regions much narrower than those machined using clamped mask.3.The cemented carbide,which is the typical mechanical seal end material,was selected to process the microgroove on its surface.The influences of nozzle moving rate,feed,jet pressure,jet distance,and abrasive concentration on machining quality of micro-grooves were investigated experimentally.Furthermore,the erosion and crack formation mechanism of T-MAJM based on jet angle was presented.The result of the study show that it is feasible to use a relative low-pressure synthetic diamond slurry jet to machine crack-free micro-grooves without causing any subsurface damage in a small erosion angle.