Process Safety
This semi-quantitative risk assessment tool evaluates the effectiveness of independent risk reduction measures between an initiating event and an unwanted consequence.
What is a LOPA (Layer of Protection Analysis)?
This type of non-Newtonian fluid behaves as a rigid body at low stresses but flows as a viscous liquid once a certain yield stress threshold is exceeded.
What is a Bingham plastic?
This fundamental mathematical model relates the chemical reaction rate constant $k$ to temperature using an exponential dependency on the activation energy.
What is the Arrhenius equation?
Total capital investment for a chemical processing plant is traditionally calculated as the direct sum of these two distinct types of capital.
What are fixed capital and working capital?
This mass transfer dimensionless parameter represents the direct ratio between the viscous diffusion rate and the molecular diffusion rate.
What is the Schmidt number?
This parameter describes the lowest concentration of a combustible dust suspended in air that is capable of propagating a deflagration.
What is the Minimum Explosible Concentration (MEC)?
This phenomenon occurs when rapid changes of pressure in a liquid lead to the formation of small vapor-filled cavities that violently collapse, damaging pump impellers
What is cavitation?
This reactor sizing parameter is defined as the time necessary to process exactly one reactor volume of fluid based on specified entrance conditions.
What is Space Time?
Created after the Tax Reform Act of 1986, this tax depreciation framework is the primary method currently utilized by U.S. industrial businesses for asset recovery.
What is MACRS (Modified Accelerated Cost Recovery System)?
This dimensionless number plays a key role in natural convection calculations and defines the ratio of buoyancy forces to viscous forces acting on a fluid.
What is the Grashof number?
This 1976 industrial accident in Italy involved the catastrophic release of a highly toxic dioxin cloud (TCDD), leading to a famous series of European safety directives.
What is the Seveso disaster?
This thin layer of fluid in the immediate vicinity of a bounding surface is characterized by prominent viscous forces and holds a velocity gradient ranging from zero to the free-stream velocity.
What is a boundary layer?
This semi-empirical relationship is widely utilized in chemical engineering to calculate the frictional pressure drop across a packed bed reactor.
What is the Ergun equation?
According to standard plant design estimation techniques, capacity, material of construction, and operating pressure represent the three main factors that dictate this parameter.
What is the capital cost of a specific piece of equipment?
Utilized heavily in transient heat conduction, this dimensionless group is calculated as the ratio of the heat conduction rate to the rate of thermal energy storage in a solid block.
What is the Fourier number?
This specific type of spring-loaded relief valve uses a mechanical barrier to protect the spring and guiding parts from the process fluid and minimizes the effect of backpressure.
What is a balanced bellows relief valve?
This type of mass transfer mechanism dominates inside porous catalyst particles when the mean free path of the gas molecules is significantly larger than the pore diameter.
What is Knudsen diffusion?
This standard kinetic equation is used to mathematically describe the rate of enzymatic reactions as a function of substrate concentration.
What is the Michaelis-Menten equation?
This economic parameter represents the net fixed capital investment of a plant asset minus the value of the land, evaluated specifically at the end of its projected useful life.
What is the salvage value?
Critical in open-channel hydraulics and wave behavior, this dimensionless number measures the exact ratio of inertial forces to gravitational forces.
What is the Froude number?
This deductive, top-down risk assessment method uses Boolean logic gates like "AND" and "OR" to identify the combinations of failures that lead to a specific hazardous event.
What is a Fault Tree Analysis (FTA)?
This physical dimension is reduced in a pipeline to cause an intentional increase in fluid velocity assuming a constant mass flow rate.
What is the inner pipe diameter?
In a packed bed reactor, the transition to a fluidized bed occurs exactly when the upward fluid drag forces become equal to this downward force.
What is the gravitational force (or weight of the particles)?
For a process with annual sales of $100,000, operating expenses of $20,000, depreciation of $10,000, and a 50% tax rate, this represents the total annual cash flow.
What is $45,000?
This geometric radiation heat transfer parameter represents the fraction of radiation leaving surface 1 that successfully strikes surface 2.
What is the view factor?