Flow through Packed and Fluidized Beds
Chemical engineering operations commonly involve the use of packed and fluidized beds. These are devices in which a large surface area for contact between a liquid and a gas (absorption, distillation) or a solid and a gas or liquid (adsorption, catalysis) is obtained for achieving rapid mass and heat transfer, and particularly in the case of fluidized beds, catalytic chemical reactions. You will find a good deal of information about flow through packed and fluidized beds in the book by McCabe, Smith, and Harriott (1) and Perry’s Handbook (2). Here, only a brief summary is given. First, let us consider flow through a packed bed.
Packed Column With Wet Scrubber For Boiler Exhaust Purification
Diesel and Heavy Fuel Oil (HFO) emit Sulphur and Nitrogen Oxides when combusted in boilers. Industrial boilers burn large amounts of fuel for steam generation. It has become essential to control these gas emissions from boilers due to sensitivity to the environment. Packed column is a technology used for Gas absorption process and distillation process in industrial applications. This research mainly targets on utilizing packed column gas absorption for purification of Exhaust gas in HFO Boiler exhaust. Industrially available economical packing materials cannot withstand high temperature flue gas exiting a boiler. The discussed solution used a combination of a packed column and a wet scrubber to achieve the optimum performance and cost of packed column absorber. Cooling effect created by the scrubber made it possible to use an economical packing material where the packed bed operated at $90^{\circ}\mathrm{C}$ temperature.
The role of dissolved oxygen in supercritical water in the oxidation of ferritic–martensitic steel
Abstract To assess the role of dissolved oxygen in supercritical water on the growth processes of oxide scales, a marker experiment of ferritic–martensitic steel was performed by exposing to supercritical water (H 2 16 O) containing marked 18 O 2 at 600 °C under 25 MPa. The oxide scale was analysed by using Secondary Ion Mass Spectrometry (SIMS). The oxygen isotope profile shows that dissolved oxygen and supercritical water react with metals simultaneously. Dissolved oxygen changes the oxidation/reduction potential of supercritical water leading to an increase in the oxidation rate. The oxidation rate increases with increase in dissolved oxygen content in supercritical water. The mechanism of the effect of dissolved oxygen on oxidation is discussed.