DIRECT VISCOSITY MEASUREMENT AT HIGH TEMPERATURES

摘要

The request of a Fluor Daniel Corporation client to measure the process viscosity of a hydrocarbon liquid,such as stripper bottoms, at a base temperature of 210 °F, has influenced the design of a new sampletemperature conditioning system. The intent of the new design is to measure the process viscosity directlyand continuously at constant base temperature of 210 °F. The system response time is specified such as tobe suitable for closed loop control.Fluor Daniel Control System Engineering and Solartrons' experience in the field of viscosity measurementwere utilized to develop the new sample temperature conditioning system for measuring the processviscosity at controlled constant temperature (selected base temperature). The Viscometer was installed in aslip stream where the sample flow rate is flow controlled providing the following:1. Turbulent mixing to provide a homogeneous uniform composition, temperature, and viscosity.and, as a fall back condition:2.As fall back condition, the viscosity measurement of the process stream at the flowing temperature canbe used to calculate the base viscosity (at base temperature) using the "Indirect" referral method, in theevent of temperature control failure. The indirect or referral method is based on ASTM D341-93equations through which the viscometer is configured with in-situ calibration.Following acceptance of the final system design the client, The new sample temperature conditioningsystem was built and tested successfully. The system has passed its Factory Acceptance Tests in 1999.TheFAT ( factory acceptance test ) results of the final design of the sample temperature conditioning systemhave demonstrated the system capability to measure the viscosity of the process stream directly andcontinuously at the selected base temperature 210 °F with accuracy +1 °F, and viscosity accuracy + 1% FS(Full Scale).The system has been installed, commissioned and has passed its Site Acceptance Tests. Thesystem will be fully operational in April 2000.