催化剂支撑盘由支撑大梁（T型或I型）、格栅和上部V型丝筛网组成。大梁的两边搭在反应器器壁的凸台上，而格栅则放在大梁和凸台上。格栅上焊接V型丝筛网或者平铺两层粗细不锈钢丝网，格栅上部装填磁球和催化剂。催化剂支撑大梁和格栅要有足够的高温强度和刚度。不仅要求高温下弯曲变形很小，且具有一定的抗腐蚀性能。因此，大梁、格栅和丝网的材质一般均为不锈钢。在设计中考虑催化剂支撑盘上催化剂和磁球的重量、催化剂支撑盘本身的重量、床层压力降和操作液重等载荷，经过计算得出支撑大梁和格栅的结构尺寸。 The catalyst is chosen for its efficiency, its stability and selectivity. The required volume of catalyst is referred to as bed extending over a fixed height for a given reactor diameter.The catalyst loading diagram is the general scheme with the sequence of inert balls, and different types of catalyst, each one having its specific size and bulk density.The catalist layers can extend in one bed or several beds in a multi bed reactor, in such a way that several support grids have to be installed in the same reactor.Under axial flow operations, the support grid Assembly has to withstand vertical process loads. The grids have to be reinforced or supported by extra beams adding extra strength to the assembly.T or I shape beams can be used. T- beams generally are used for high design pressure allowing the possibility to immerge the important height of the web inside the bed above the grid. I- beams, on the contrary is more commonly used for lighter design pressure, allowing to position the beam below the grid.The support grid is installed on a ring integral to the pressure shell. It has to be built in sectors to enable its installation through the vessel manhole. Some processes require a locking system to secure the panels.A small gap is left with the inside of the vessel wall in order to allow differential thermal expansion and installation clearance and to handle manufacturing tolerances or out of roundness of the reactor itself.Rope packing for catalyst sealing.