Research On Working Stablity Of Dry Gas Seal

For the purpose of higher stability, face opening at dry gas seal starting and stopping; groove shape reform and proper monitoring system set up are investigated. Several methods are proposed from different point of view to enhance dry gas seal working stability.Firstly, touch status at seal starting and stopping is analyzed through detailed study on face opening force at seal startup. Because too low rotate speed at seal starting and stopping, there's no enough opening force to open seal's face, so the two faces of the seal will directly touched, Result in badly friction and wear, it's too disadvantage to seal. Face opening concept is proposed to avoid face directly touch. Three possible projects of face opening are researched based on the type of B823d, their advantage and disadvantage is analyzed contrastively.Secondly, Numerical calculating use FLUENT is carried out, emphases on hydrodynamic pressure's forming, distributing, and carrying capacity. Characteristic of fluid field pressure distributing is: at the intersection of groove and stage, there's clear change of film pressure, at the place gas flow into, pressure will depressed, negative pressure (relatively) zone formed; at the place gas flow out, pressure will increased, hydrodynamic pressure is formed. The two type of pressure distributing zone will displace and reformed with different screw-angle and different press difference of import and export.After sufficiency study of seal face fluid field, reforming groove shape is proposed to gain higher hydrodynamic domino offect. Through optimize the parameters of dry gas seal used by compress machine, and then the optimized seal groove shape and primary groove shape seal is analyzed contrastively, emphases on film stiffness and opening force, result shows: gas film stiffness and opening force will improve by optimizing groove shape, higher stability is gained.Thirdly, the new method by use CCD measure face clearance is proposed through sufficiency study of traditional measurement methods. The key of the new method is how to improve common CCD's measurement precision, base theoretical...