The activated sludge process (ASP) is designed to speed up the rate of decomposition of waste material in water. First developed in 1914, it remains an important means of treating both municipal and industrial wastewaters. This one-page reference provides information…
Corrosion is an obvious factor to consider when selecting materials of construction for process equipment. However, the chemical environment of the process is only the starting point in selecting an acceptable material. A set of other factors can complicate corrosion-resistance…
All chemical process industries (CPI) operations involving combustion need to be concerned with the emission of combustion products, due to their potential environmental and health impacts. This one-page reference provides information about several of the most common combustion byproducts from…
Process industry plants install sophisticated air-pollution control systems, but they can be ineffective if the flowmeters on which they rely deliver inaccurate or unreliable data. This one-page reference provides information on measuring the flow of gaseous combustion products in large…
High-shear, high-speed mixing equipment supplies the mechanical energy necessary to reduce the size of solid particles and liquid droplets in emulsions and dispersions. Emulsions are mixtures of two normally immiscible liquids in which tiny particles of one liquid are suspended…
Agglomeration and granulation are used to achieve a wide range of objectives in solids-handling processes, including to ensure a desired particle-size distribution, minimize segregation, and improve solids flow, as well as to control de-aeration and compaction behavior and attrition resistance…
Cake filtration is a common operation across many sectors of the chemical process industries (CPI). In cake filtration, the solid being filtered acts as a screen so that particles of the suspension are retained by the medium, resulting in the…
The components of air (Table 1), especially nitrogen (N2) and oxygen (O2), are critical for many modern industrial processes. Primary metals production, chemical manufacturing, gasification processes, clay, glass and concrete production, welding and other processes depend on O2 from air,…
Heat-transfer fluid selection can be intimidating when considering the long-term impact on costs and operability. The right fluid will provide optimal performance and lifecycle costs, while freeing engineers for other assignments. Most engineers do not routinely consider fluid selection, so…
Blending is a fundamental chemical unit operation, and there are a handful of common ways to implement it. Blending applications can be either manual or automated, and can be carried out either as a batch or continuous process. There are…