Main fan anti-surge valve

“I would like to ask how the anti-surge valves for the main fans in other refineries are designed. ”. First, you need to understand the principle of surge and the conditions under which it occurs. One should understand the principle of this self-protection system before deciding whether it is reasonable and whether changes are needed. For reference.

A secondary line can be added, with a chain valve or isolation valve installed on it.

We have indeed installed two anti-surge circuits here, one large and one small; the small one is used for fine adjustments, while the large one activates during interlocks.

If it cannot be opened, when the main air interlock is activated, the air supply valve to the regenerator will close; as a result, air cannot flow out and pressure will build up. It is recommended to carry out maintenance work to add an additional air supply line

1. Add a secondary valve; the selector valve can be used； 2. Conduct a static test before starting up to check whether the interlock valves function smoothly and properly ； 3. Periodically operate the interlock valve on a small scale.

What is the scale of your installation? My installation is equipped with 2 anti-surge valves

1 What is the OP worried about? What if it still can’t be opened even with 2 installed? In the worst case, there is no bottom to it. 2 Our fans are equipped with anti-surge valves, and it is essential to ensure their proper functioning through appropriate selection and maintenance. 3 One of the key points mentioned by a colleague on the 8th floor is as follows: 3.1. When the fan’s airflow volume is high, such as in steel mills where AV100 or higher model fans are used, with flow rates reaching tens of thousands per minute, a valve with a large diameter is required if full exhaust is to be achieved. 3.2. When the valve is large enough, mechanical issues arise regarding the speed at which it can be opened and the impact of the valve plates during opening; in other words, it depends on whether the user’s requirements can be met by the valve’s manufacturing capabilities. 3.3. Generally, anti-surge valves are butterfly valves, and there is a nonlinear relationship between the degree of valve opening and the flow rate. When the fan’s operating point is close to the anti-surge line and the valve needs to be partially opened, oscillations can occur unless the valve has very high sensitivity and precision. 4. It is unknown how steel mills implement anti-surge measures; the above is merely speculation. Our catalysts have not yet reached such a high airflow rate; using an AV90 is already considered quite high. It is possible that, taking into account the factors mentioned above or even more complex factors, a parallel dual-valve setup was adopted. In my opinion, among the reasons for adopting a dual-valve system, it is not likely that the inability to open a single valve is the primary factor.