固定床移动床的特点（Characteristics of fixed bed moving bed）.docVIP

固定床移动床的特点（Characteristics of fixed bed moving bed） Fixed bed: A fixed bed reactor, also known as a packed bed reactor, is a reactor filled with solid catalysts or solid reactants for the purpose of achieving a heterogeneous reaction process. Solids are usually granular, with sizes ranging from about 2 to 15mm and piled up into beds of a certain height (or thickness). The bed is stationary and the fluid reacts through the bed. It differs from the fluidized bed reactor and the moving bed reactor in that the solid particles are in a quiescent state. Fixed bed reactors are mainly used for gas solid phase catalytic reactions, such as ammonia synthesis tower, sulfur dioxide contact oxidizer, hydrocarbon steam reformer, etc.. The bed is filled with solid reactants when it is used for non catalytic reactions in gas-solid or liquid solid phases. The trickle bed reactor can also be attached to a fixed bed reactor, and the gas and liquid phase flows down through the bed to form gas liquid solid phase contact. 1, classification The fixed bed reactor has three basic forms: axial adiabatic fixed bed reactor. The fluid flows through the bed layer from top to bottom along the axial direction, and the bed layer has no heat exchange with the outside. Radial adiabatic fixed bed reactor. The fluid flows through the bed along the radial direction, which can be centrifugal or centripetal, and the bed has no heat exchange with the outside. Compared with axial reactor, radial flow reactor has shorter distance, larger cross section area and less pressure drop of fluid. However, the structure of the radial reactor is more complicated than that of the axial reactor. The above two forms are adiabatic reactors, which are suitable for occasions where the reaction heat effect is not very good, or the reaction system can withstand the temperature change caused by the reaction heat effect under the adiabatic condition. The tubular fixed bed reactor. The utility model is composed of a plurality of r