Size Selection And Function of Inert Ceramic Balls

The size selection of inert ceramic balls should be based on the size of the catalyst. Generally, the 2X rule (or gradation) is followed, that is, the diameter of the ceramic ball should be twice the diameter of its adjacent catalyst, so that the material distribution must be uniform and the pressure The smaller the drop, the more the reactor needs to be optimized.

In a fixed bed reactor, a certain height of inert ceramic balls or fillers are usually added above and below the catalyst. The function of the upper ceramic ball is easier to understand and improves the feed distribution. What does the lower porcelain ball do? Is it just catalyst support? Is it possible not to use it?

In addition, there are rigid regulations on the filling height of inert ceramic balls. What is the basis for this prescribed height?

Usually two layers are laid, with 1-3mm porcelain balls on the layer close to the catalyst, 4-6mm porcelain balls on the outer layer, and a wire mesh on the outside. The wire mesh mainly plays a role in gas distribution, filtering small particle catalysts entrained by the gas or filtering impurities entering the bed. It also prevents the bed from falling and supports the bed. Generally, porcelain balls of each specification are laid 100mm thick. I didn't notice that there was a stipulation in that standard. Even very fine catalyst particles cannot be filtered by this method, and other methods need to be used to filter the catalyst that may be brought out.