Retrofit of a Rubotherm ISOSORP® 2000 for PVT-x and sorption measurements at cryogenic temperatures

Abstract

Type V composite storage tanks have significantly increased the working pressures of cryogenic systems for aerospace applications. However, the current operating pressures often exceed the range of available mixture property models and measurements. The majority of cryogenic mixture property measurements are historical, having not been reviewed in over 40 years, which represents a growing problem. This paper describes the retrofit of an established Rubotherm ISOSORP® 2000 dual-sinker densimeter for cryogenic service. Design of a cryostat with vibration-isolation bellows to minimize vibration from the pulse-tube cryocooler is presented. Parasitic heat load calculations are provided to estimate the minimum operating temperature. The system is capable of achieving pressure up to 30 MPa. The design and anticipated capabilities of the experimental system are described.