Study On Slag Flowing Characteristics In Gasifier Slag Notch

On the background of the problem of slag basin blocking at long-period industrial run of Shell gasifier, a cold model of slag flow experimental platform was established in the laboratory and syrup was employed as medium. The slag flow characteristics in gas-slag countercurrent and gas-slag cocurrent were mainly studied in this paper.When it is gas-slag countercurrent flowing, slag isn't free falling from slag notch, but rotation happens induced by rotary flow field in Shell gasifier and finally liquid film broke up into liquid strips, the part of slag deposits on slag screen is inevitable. The main factors influencing slag adhesion in slag screen are experiment load, nozzle gas velocity, slag flow yield, and slag viscosity etc. A slag flowing mathematical model was built and calculated, the results show that:the thickness fo solid slag on screen is about several hundreds of mm in the range viscosity of gasifier liquid tapping. The solid slag thickness is so big that it is easy for big solid slag dropping into the slag basin, and large slag is formed which blocking the slag basin hole.Gas-slag cocurrent flows, slag velocity is constant at the gasifier notch, accelerated after leaving the notch, and forced into a closed liquid droppinginto the slag basin, while slag flow only by gravity. When there is gas flow in gasifier, slag flow form in the inner tuber under notch is influenced by experiment load, notch gas inlet velocity, slag flow yield etc. Fluid flow under the notch is confined inlet jet, the expanding angle of inlet jet, recirculation zone, velocity distribution, and pressure distribution are related to the diameter ratio of inner tuber and notch. When the ratio decreases, the adhension of slag depositing in inner tuber fall off slag notch will increase significantly. Comparing the adhension of slag depositing in inner tuber fall off slag notch, the style of gas-slag countercurrent is more serious than that of gas-slag cocurrent.