# Welcome to Neutrium

Neutrium is a knowledge base of engineering topics, centred mainly around chemical engineering design challenges faced by engineers in their daily work. We created Neutrium to bridge the gap between theory and practice. Feel free to ask a question, leave feedback or take a look at one of our in-depth articles.

This article provides thermal conductivity data for a selection of common materials. Thermal conductivity measures a materials ability to allow heat to pass through it via conductance.

For some engineering calculations, particularly in hydrocarbon processing, it is necessary to estimate the viscosity of a mixture (blend) of two or more components. This article presents the Gambill and Refutas methods, which are commonly used in petroleum refining for predicting the viscosity of oil blends.

This article lists the standard effective orifice areas for the orifice designations found in API RP 526 5th edition. These orifice designations set the minimum effective orifice area which a relief valve must have to meet the API 526 requirements and must be used with the sizing equations in API RP 520 Part I.

Torque is an important parameter in ensuring motors are well suited to their intended service. This article demonstrates how to calculate torque for a given motor or drive, and provides a brief introduction to motors and torque.

The moment of inertia of a pump is its resistance to changes in angular velocity as it rotates about its shaft. Knowledge of the moment of inertia of a pump, motor and associated components is typically required for transient analysis of a pumped system. This article presents methods by which pump and motor moment of inertia may be estimated.

Reading values from a graph or plot with a logarithmic axis visually is difficult and will often result in inaccurate readings. This article presents formulae which may be used with measurements from a graph axis to obtain more accurate values.

Pump Specific Speed, NS is a method of characterising a pump duty by head, flow rate and rotational speed. Pump specific speed may be used to determine an appropriate pump design for a given application when choosing between axial, radial or multistage centrifugal designs or positive displacement pumps.

As fluid flows through a packed bed it experiences a pressure loss due to friction. This article describes the use of the Carman-Kozeny and Ergun equations for the calculation of pressure drop through a randomly packed bed of spheres.

Birmingham Wire Gauge (BWG), also known as Stubs Iron Wire Gauge is a system of measurements describing thickness. BWG has been historically used to describe the outside diameter of small tubes and wires, as well as the wall thickness of some large tubes (such as those used within a shell and tube heat exchanger). This article presents length conversions for BWG values into metric and imperial units.

There are many operations in which two phases must be separated. These separations may be gas-liquid, gas-solid, liquid-liquid or liquid-solid, with several factors such as relative densities, gravity, fluid velocities and the shape of particles and/or droplets influence the phase separability. In this article we present the fundamentals of these separations and provide the Stoke's, Intermediate and Newton's formulae for calculating the terminal velocities of settling particles to analyse separation systems.