Inert ceramic balls are solid ceramic spheres made from raw materials such as kaolin, alumina, quartz, etc., through molding and high-temperature sintering. They are chemically inert and do not participate in reactions. They have high strength, high temperature resistance, resistance to acid and alkali corrosion, low wear, and low soluble iron/sulfur/chlorine content. They are the most commonly used bed support packing materials for fixed bed reactors and adsorption towers. They are classified as follows:
1. Ordinary low-aluminum ceramic balls (with Al₂O₃ ranging from 17 to 19%)
2. Medium-aluminum ceramic balls (with Al₂O₃ ranging from 30 to 45%)
3. High-aluminum ceramic balls (with Al₂O₃ ≥ 70%, 90%, 99% corundum ceramic balls)
In addition, there are grinding ceramic balls used for ball milling to crush materials, which have completely different uses from the supporting ceramic balls for reactors.
Main functions:
1. Supporting and bearing weight (large-grained ceramic balls at the bottom)
Support the upper catalyst/molecular sieve, distribute the weight of the catalyst to the bottom grid of the reactor, prevent fine catalyst particles from leaking into the grid and blocking the outlet. Generally, a “graded filling” method is adopted: from large balls to small balls transition.
2. Uniform fluid distribution (core process function)
The gas and liquid fluids pass through the gaps between the ceramic balls, constantly分流 and mix， eliminating bias flow and channel flow， allowing the material in the entire cross-section to uniformly contact the catalyst， improving the overall conversion rate of the reactor， and reducing local overheating and rapid catalyst deactivation.
3. Buffering impact and protecting catalyst
A ceramic ball layer at the top is laid to buffer the impact force of the feed gas/liquid flow， avoiding direct scouring， abrasion， and crushing of catalyst particles by high-speed fluids， reducing catalyst powdering.
4. Blocking catalyst fines and preventing downstream blockage
The bottom ceramic ball layer intercepts the dust produced by catalyst wear， preventing fine dust from being carried into the downstream pipelines and heat exchangers， and preventing rapid increase in pressure drop.
5. Protecting catalyst from poisoning
The raw materials are strictly controlled to exclude soluble iron， sulfur， chlorine， boron and other toxic substances，so no impurities will be produced and pollute the catalyst.
