Airspeed—what is the meaning of this concept?

It is related to the residence time of the material in the catalyst.

Definition of space velocity: The ratio of the amount of feed material entering the reactor per hour to the volume of the reactor is called space velocity, abbreviated as SV. If both the feed rate and the inventory are expressed in weight units, it is called weight space velocity ； If both the feed rate and the inventory are expressed in volume units, it is called volumetric space velocity. Weight space velocity = Total feed rate (t/h) / Storage capacity (tons). Volume space velocity = Total feed rate (cubic meters/hour) / Storage capacity (cubic meters). When calculating volume space velocity, the volumetric flow rate of the feed is determined based on the liquid flow rate at 20°C. What he represents is the volume of fluid that passes through a unit of catalyst per unit of time. Numerically, the space velocity and contact time are inverses of each other. In a fixed-bed reactor, the reaction efficiency is closely related to the contact time. As we know, it is the active metal components in the catalyst that drive the reaction, and these active components are located on the surfaces of the catalyst’s pores. If the contact time is too short, the reactants pass by before they have the chance to come into contact with the active components in the deeper pores; in such cases, those active components are wasted, and it is inevitable that the desired reaction results cannot be achieved. On the other hand, if the air velocity is too low, meaning the reaction time is too long, it will lead to excessive reactions and increased carbon buildup, which is also not conducive to long-term operation. This post was last edited by yfq4308 on 2009-4-3 11:44]

Multiplying by something allows for estimating capacity.

It’s an interesting question; indeed, it’s a bit difficult to understand the meaning of space velocity from a mathematical perspective. However, it can be expressed more intuitively in this way: space velocity represents the intensity of use of the catalyst/reactor. A high space velocity implies a large amount of feedstock (since the catalyst/reactor volume remains constant), but it should be noted that there is no linear relationship between space velocity and reaction intensity – not all of the feedstock gets converted (see reaction conversion rate).

The space velocity not only reflects the issue of residence time but also the processing capacity of the unit; the higher the allowable space velocity, the greater the processing capacity of the unit

Airspeed is only a rough indication of the processing situation

It seems that the value of the air velocity is proportional to pressure to some extent; please give me your guidance