Effective Emergency Relief System (ERS) design helps companies meet risk-management goals, compliance requirements, and sound business practices. ioMosaic provides a total ERS solution with our comprehensive ERS design services, from reactivity testing for design basis determination to calculations for Z-axis deflection from dynamic loads.
Our team has decades of experience performing PRFS analysis and design.
Our risk-based approach helps mitigate near-unventable scenarios to a tolerable level of risk.
Better evaluate hazards in your facility with an accurate process simulation.
Delivering properly designed pressure relief systems that save both money and time.
Read this white paper to understand how and who determines the maximum allowable working pressure (MAWP), the relationship between MAWP and Design Pressure, and finally how high-pressure vessel is designed.
Two-phase flow is often considered in system hydraulics as well as the evaluation and design of pressure relief and effluent handling systems. A variety of scenarios can lead to two-phase flow under relief conditions.
In general, two-phase flow during relief can occur because of flow hydrodynamics and poor vapor/ liquid disengagement where (a) the liquid swells due to generation of vapor bubbles in the liquid 1, (b) fluid expansion occurs due to heating, and/or (c) the superficial vapor velocity is high enough through the pressure relief device. Oversized relief devices can induce two-phase flow because a large relief flow area yields a higher superficial vapor velocity. Runaway chemical reactions and/or chemical systems that are viscous and/or foamy almost always lead to homogeneous two-phase flow.
Two-phase flow can also occur by entrainment, for example, where gas is sparged at a high enough rate in the liquid. In some systems, condensation leading to two-phase flow in the discharge piping can also occur due to expansion cooling caused by pressure reduction through a control valve or a pressure relief device.
Numerous two-phase flow models have appeared in the literature. These models represent broad ranges of theory. Some are based on single-phase critical flow, others on homogeneous equilibrium flow, frozen flow, separated flow, slip flow, and/or non-equilibrium flow.
Homogeneous equilibrium flow models assume equal vapor and liquid velocities and calculate the change of quality with pressure using an isenthalpic or isentropic thermodynamic path. Homogeneous frozen models assume equal vapor and liquid flow velocities and that the quality is frozen along the flow path, i.e., no change with respect to pressure or temperature. The separated flow models assume different vapor and liquid flow velocities and account for mass, momentum and heat transfer between the separate phases.
Process Safety Enterprise Emergency Relief System Design Workflow performs efficient tracking of process safety related data and analysis. The customized workflow allows for a specific operating unit or the entire facility to be studied and evaluated to maintain compliance and ensures your facility remains protected.
The client was storing reactive materials in vessels that could be subject to fire exposure. They wanted to be sure that the relief protection on the vessels was correctly sized, or if not, what changes were necessary for an effective relief system.
Apr 30, 2021
Apr 20, 2021
Apr 1, 2021