The thermal conductivity of hydrocarbons is an essential parameter that needs to be known when designing heat transfer equipment. Presented here is a simple-to-use correlation that was developed for predicting thermal conductivities of liquid paraffin hydrocarbons, petroleum fractions and atmospheric…
Laminar Pipe Flow For steady flow in a pipe (whether laminar or turbulent), a momentum balance on the fluid gives the shear stress at any distance from the pipe centerline. In Equation (1), Φ = P + ρ gz. The…
Biodiesel can be produced from vegetable oils by three types of reactions: base catalyzed transesterification of the oil; direct acid-catalyzed transesterification of the oil; and conversion of the oil to its fatty acids, and then to biodiesel. Biodiesel is typically…
Process modeling has progressed from the "molecule accounting" of steady-state flowsheeting packages to become a central platform for capturing and deploying chemical process industries’ (CPI) intellectual property (IP). Systematic modeling has moved center stage to help companies differentiate themselves from…
Pressure relief systems are vital in the chemical process industries (CPI) for handling a wide variety of situations. They are used to prevent pressurization above a system’s design pressure; for venting during an unusual or emergency situation; and for…
Management is a process of managing risk; maintenance management is a process of managing risk for operational reliability. Since it is hard to manage what cannot be measured, effective maintenance management demands good data on machine health — a comprehensive…
A very common heat exchanger in the chemical process industries (CPI) is the vertical thermosiphon reboiler (VTR; Figure 1). Due to size and fluid-flow restrictions, however, its heat transfer rate is often quite low. The subcooled region formed at the…
Pumps Centrifugal pumps with cast or forged steel casings are typically appropriate for systems with large flowrates Positive displacement pumps frequently can handle smaller flowrates of less than 100 gal/min Sealless pumps (canned motor or magnetic drive) avoid the installation…
The perfect valve to control your process has been selected. The valve will pass your maximum flow. Everything is great, right? In some cases digging a little deeper might help. The control valve usually should not be the most…
The role of valves in a process is far from insignificant. These components enable engineers to control the vitals of a process: temperature, pressure, concentration, and flow. In some cases, the failure of a valve could be catastrophic and in…