Seeking help with catalytic device

Is it because your actual processing volume is lower than your designed capacity, resulting in too few openings and closings of the flap valve?

Is there coking inside the material leg? This post was last edited by chengkang on 2009-4-18 at 12:41.]

The raw material is not being atomized properly; replace the nozzle, adjust the feed temperature or the atomization steam or the pre-lift steam. This post was last edited by chengkang on 2009-4-18 12:44]

1) The low catalyst circulation rate results in an excessive residence time in the material leg. 2) The initial centrifugation effect is poor, leading to inadequate separation of oil and gas. Suggested solutions: 1) Increase the linear speed of centrifugation; 2) Increase the steam injection into the reaction system; 3) Raise the catalyst circulation rate

A poor atomization effect of the feed material is likely the main reason. Additionally, it is important to check whether the installation angle of the flap valve and the verticality of the cyclone separator meet the specified requirements; an excessive installation angle of the flap valve, or an increase in its angle under operating conditions due to deviations in the cyclone’s verticality, can lead to an extended opening and closing cycle of the valve, thereby causing coking. It is also important to ensure that the wing valve is cleaned thoroughly before starting operation. This post was last edited by chengkang on 2009-4-18 21:54]

The areas where coking occurs in catalytic units are generally the riser, settler, centrifugal leg, flap valve, oil and gas pipelines, etc； If coking occurs only in the wing valve, several factors generally need to be considered: 1. Whether the actual operating linear speed deviates significantly from the design value. 2. The installation angle issue of the flap valve. Today, many devices have accumulated a great deal of experience in preventing coking, thereby achieving long-term operation. Generally, it is considered from the following aspects: 1. Improving the feed nozzle. (Mainly to improve atomization effect) 2. Increase the steam injection volume. (Increase the partial pressure of oil and gas) 3. Control a reasonable line speed. (Key! ! ! ! ! When working with catalysis, it is essential to pay attention to the linear velocity; one must know how to calculate it and cannot rely on guesswork! ）

Be careful when using anti-scorching steam, and the raw materials used for processing should not be too heavy

　　It is likely that the catalyst load entering the secondary centrifuge is extremely low, resulting in a reduced scouring force on the wall surface; moreover, the catalyst mass flow rate in the feed leg is very small and the residence time is long. As a result, coking easily occurs on the outer wall of the secondary exhaust pipe of the two-stage centrifuge, as well as at the bottom of the ash hopper, the inlet to the feed leg, and the flap valves. As the content of high-boiling-point components in the feed increases, or due to low-temperature operation caused by fluctuations that leads to an increased degree of \"wetting\" on the surface of the catalyst particles, the tendency to coking increases. 　　Currently, a quick separator at the outlet of the riser is often used in conjunction with, or directly connected to, a single-stage top swirl separator, in order to increase the catalyst mass flow rate in the top swirl section. **It reduced the residence time of the catalyst in the leg. At the same time, select high-efficiency centrifuges and arrange them appropriately to ensure installation quality. Additionally, operations should be carried out smoothly during production to minimize fluctuations ； During maintenance, the coke must be removed thoroughly to avoid the presence of \"coke cores,\" which increases the tendency to coking.

The flap valves become clogged, resulting in inflexible operation; this is a very likely occurrence and can happen at any time for that catalytic unit. . . The key technical measure to reduce coking is as follows: 1. Select catalyst materials appropriately and control the residue carbon value; it is better to ensure stable operation of the plant over a long period rather than pursuing short-term gains by blindly and unscientifically choosing raw materials with high residue carbon levels that are difficult to crack. . . 2. Reasonably determine the reaction temperature, reprocessing ratio, and circulation volume to reduce the coking rate of the feedstock and maintain a low level of heavy oil inside the settler and lift pipe. . . So the likelihood of coking is reduced. . . :lol

Reasons: 1. Low centrifugal separation speed; 2. Poor reaction and poor atomization; 3. Incorrect angle of the flap valve; 4. Large variations in raw materials

What is the reason why only the gas collection chamber, the outer wall of the top rising gas pipe, and the material legs in the settler experience coking, while the flap valve does not?