Countercurrent exchange

About: Countercurrent exchange is a research topic. Over the lifetime, 2255 publications have been published within this topic receiving 28687 citations. The topic is also known as: Countercurrent exchange.

Countercurrent reactor with interstage stripping of nh3 and h2s in gas/liquid contacting zones

Abstract: A reactor for reacting liquid petroleum or chemical streams wherein the liquid stream flows countercurrent to the flow of a treat gas, such as a hydrogen-containing gas. The reactor is comprised of at least one vertically disposed reaction zone, each containing a bed of catalyst, wherein each reactionzone may contain vapor bypass means, and wherein each reaction zone is immediately preceded by a non-reaction zone, and wherein each non-reaction zone contains a gas/liquid contacting zone for stripping gaseous by-products, such as NH3 and H2S, from the liquid stream.

Frictional pressure drop for turbulent gas streams in wetted-wall columns with cocurrent and countercurrent gas-liquid flow

Abstract: The flow behavior of the laminar liquid film and the turbulent gas stream flowing cocurrently or countercurrently in a wetted-wall column was studied theoretically and experimentally. Analytical solutions were obtained for the velocity profiles of gas and liquid and the frictional pressure drop for the gas stream. Frictional pressure drops for the gas stream were measured for the air-water system and the air-glycerol solution system. Experimental results were in good agreement with the theoretical predictions.

Stripping medium requirement in continuous countercurrent deodorization

Abstract: A mathematical formula was derived that allows the stripping steam requirement of the countercurrent deodorization process to be calculated as a function of system pressure, vapor pressure of the pure volatile compound, initial and final volatiles contents, and the number of transfer units (an equipment parameter) of the countercurrent deodorizer. Just as in batch or cross-flow deodorization systems, the steam requirement in countercurrent systems is proportional to the system pressure and inversely proportional to the vapor pressure of the pure volatile compound. Increasing the number of transfer units (for instance, by increasing column height) to more than two makes the countercurrent system require less steam than cross-flow systems with a vaporization efficiency of 0.6. In addition, the short residence time in a countercurrent deodorization column minimizes side reactions and allows the deodorization temperature to be raised without generating unwanted by-products such as trans-isomers and/or oligomers of unsaturated fatty acids. The increased deodorization temperature increases the vapor pressure of the pure volatiles and leads to further savings in stripping medium and motive steam. Countercurrent deodorization systems therefore require less energy than cross-flow deodorization systems and/or produce oil with fewer unwanted by-products.