The Research Of Dry Gas Seal For Mixer

As a new seal, dry gas seals can achieve low power consumption, long life compared with other type seals. Now the dry gas seals have been successfully used in high speed turbo compressors, however, the application with dry gas seals on mixer and agitator has some difficulties such as hard to open and large amount of the shaft runout. Therefore it's very important to analysis the sealing performance in low speed and low pressure condition and optimizes the grooves in the seal face.The CFD software Fluent was used to simulate the gas flow between the seal faces. The pressure distribution was obtained and the results showed that the gas film pressure was decreased from outside diameter to inside diameter, but the pressure in the groove areas did not change a lot because of the effect of the spiral groove. The contours of pressure showed that the dry gas seal still has some dynamic effect in low speed and low pressure condition.The sealing performance in different operation conditions and different film thickness was calculated, the results showed that high speed and low pressure were conducive to the emergence of dynamic effect, changes in the thickness of the film had a great impact on the sealing performance, the film thinner, the better it is for dynamic effect produced. When the geometrical parameters of faces of dry gas seals are changed alone, the sealing performance of dry gas seal were analyzed, with which a general rule for the optimization of the geometrical parameters was presented. The orthogonal analysis method was introduced to analyze the sealing performance in the impact of multi-parameters.By the UDF, the slip boundary was introduced to the simulation of the dry gas seals. The sealing performance both in slip boundary and non-slip boundary was compared, the results showed that the slip boundary had a great effect in the leakage but much weaker on the open force.