Diameter, economic flow velocity, and operational flexibility
Thread Content
According to the economic flow rate range recommended in the process design manual, for example, 2~2.5 meters/second； I wonder if everyone takes the following factors into consideration when determining the pipe diameter? ? When designing for 100% load, the lower value within the aforementioned optimal flow velocity range is used, such as 2.1 m/s. This allows for a larger pipe diameter, so that the flow rate remains at 2.1 m/s during 100% production capacity and at 2.5 m/s during 120% capacity; in this way, the operation stays within the optimal flow velocity range regardless of whether the load is high or low ? ? I wonder if such consideration is appropriate? ?
I don’t think there’s a high chance of it running at 120%. The pressure must be high at 120%. Either the safety valve opens, or there is a flow control device. When I design, I calculate the pipe diameter based on the upper limit of flow velocity. In fact, the calculated pipe diameter is also rounded off. You can recalculate it using the rounded pipe diameter. If the pipe diameter increases, that means higher investment costs~ especially for large pipes or special materials. .
Not necessarily? It should be handled separately based on the specific process conditions and the equipment’s capacity
When calculating the pipe diameter, the maximum flow rate should be used, and the flow velocity should be set at a slightly lower value
Based on 120% of the production capacity, the pipe diameter is calculated using the middle value of the flow velocity range; after rounding, the flow velocity is checked again.
There are also specific considerations regarding flow rate. In one project, I found that the pressure drop across the control valve used by the person in charge was a bit low, so I simply reduced the diameter of the entire pipeline by one size level, haha. Fortunately, the owner hasn’t raised the issue of low sensitivity of the control valve at the moment, haha. My understanding is that the economic flow rate is just a reference; it’s still most important to analyze each situation individually. Sometimes a lower pressure drop is required, while other times it isn’t, you know?:)
I think the original poster’s consideration is quite appropriate; that’s how it can be economical.
The original poster’s idea is good, but safety and investment in actual operation need to be taken into consideration