Technical & Practical
Tray Column Design
Here, we present criteria needed for the intelligent, effective specification of trays for a distillation or stripping column. Among the key parameters and accessories during specification are column diameter, tray spacing, number of trays, number of passes, type of downcomers,…
CSTRs: Bound for Maximum Conversion
Here, a design approach for continuous stirred-tank reactors is outlined for both reversible and irreversible second-order reactions Multiple CSTRs (continuous stirred-tank reactors) are advantageous in situations where the reaction is slow; two immiscible liquids are present and require higher agitation…
Controlling Emissions With Ceramic Filters
Ceramic filters are well suited for high-temperature processes that are subject to strict emissions limits, including those for dioxins About Incineration Incineration processes are being widely used more and more to deal with the disposal of waste materials. In many…
Active Management of Pipespool Fabricators
In today’s fast track schedules for constructing new capital facilities, the process of designing, delivering and erecting piping often falls in the project’s critical path. This is particularly true for facilities constructed in emerging economies, where the facility generally resides…
Mechanical Carbon In Chemical Processing Equipment
Frequently, in chemical processing equipment it is possible to place the shaft support bearings in the chemical that is being processed. In some cases, this precludes the use of oil- or grease-lubricated bearings because the operating conditions are not conducive…
Cover Story Part 1: Heat Flux And Film Temperature In Fired, Thermal-Fluid Heaters
In a fired thermal fluid heater, a thermal fluid is heated by the metal surfaces of a fired heater or fluegas heat-recovery exchanger. Generally, the heat input rate is controlled to achieve some desired bulk-fluid temperature exiting the heater. However,…
Heat Transfer Fluids: Maintaining the System
Organic-based thermal fluids provide relatively trouble-free service for significant periods of time. However, there comes a time when any fluid (either aromatic- or aliphatic-based) needs to be replaced. Since aromatic-based fluids generally cost more and are complicated to dispose of,…
Bearing Housing Protector Seals for Gearboxes
Lubricant contamination in gearbox bearing housings can substantially reduce gear life. In critical applications, dual-face, magnetic bearing-protector seals will keep contamination out (Figure 1). Dual-face, magnetic bearing protectors are preferred in many difficult applications, such as wet cooling tower gearboxes,…
Engineering Practice: Functions for Easier Curve Fitting
Engineers often need to fit experimental data to an empirical relationship for extrapolation or modeling without resorting to a full mathematical treatment based on physical principles or theory. The most widely used platform in science for doing this is MS…
Engineering Practice: Estimating Thermal Conductivity of Hydrocarbons
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…