Research On Magnetic Fluid Combined Seal For Food Machinery

The independent research and development ability of food machinery in China is insufficient.The relatively backward manufacturing process and integrated technology lead to the slow progress of food machinery research and development in China.Shijiazhuang Helper Food Machinery Co.,LTD.,is given priority to pasta machine production.The vacuum and flour machine is an important food processing machine,but the sealing problem of the shaft end of the equipment is difficult to solve.Severe wear and pressure failure of the sealing parts of the equipment lead to leakage,which requires frequent replacement of seals.In this paper,the combined seal structure is designed and manufactured for the sealing problem of the shaft end of the vacuum and surface mill.The purpose is to improve the pressure resistance and the applicable range of the speed of the seal,and solve the sealing failure caused by the pressure difference and the speed.It can improve the stability of the seal and prolong the sealing life,and prevent the occurrence of leakage.It is of great significance to solve the sealing problem of food machinery such as vacuum and noodle machines.Centered on this problem,this paper completed the following research:(1)A magnetic fluid combined seal scheme is proposed to solve the leakage problem of the shaft end of the vacuum and flour mill.The combined sealing scheme of magnetic fluid —spiral seal — brush seal is determined to solve a series of problems such as wear,insufficient pressure resistance,short service life,frequent replacement of seals,and so on;(2)Combined with the actual sealing conditions of the equipment,the structure design and material selection of magnetic fluid seal,screw seal and brush seal are carried out respectively;(3)The magnetic lubricating grease and magnetic lubricating oil for food machinery are developed,and the saturation magnetization is calculated by VSM test.The viscosity and temperature properties of magnetic greases and magnetic lubricants with different mass fractions and the magnetic viscosity properties under different magnetic field intensities are tested by using a rotary rheometer.The test has paved the way for the application of magnetic lubricating grease and magnetic lubricating oil for food machinery;(4)The magnetic field of the combined magnetic fluid seal is simulated by ANSYS finite element simulation software.The distribution diagram of magnetic force line,the vector diagram of the magnetic flux density,the distribution diagram of magnetic induction intensity,and the distribution diagram of magnetic induction intensity in the seal gap are solved.The rationality of the parameters related to the design of the magnetic fluid seal structure is verified.The minimum theoretical pressure resistance of the magnetic fluid combined seal structure is 0.158 MPa,which meets the pressure resistance requirement of 0.085 MPa by using the theoretical pressure resistance formula.65 figures,8 tables,58 references.