What is drift current? ? How to avoid it?
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What is drift current? ? ? What is its performance like? ? How to avoid the occurrence of bias current?
Unbalanced flow generally refers to the uneven distribution of flow rate among the parallel branches, which has adverse effects. In heating furnaces, the branch with a lower flow rate is prone to coking; in air coolers, the one with a lower flow rate is likely to freeze. It is necessary to strengthen monitoring and adjustment to maintain consistent flow rates across all branches. In terms of design, the various branches should be arranged as symmetrically as possible.
This phenomenon occurs not only at the feed to the furnace, but also whenever the flow is divided into two or more streams; flow deviation can happen in such cases. For example: riser feed. The material enters multiple heat exchangers. Shunting. Stable two-way water injection, etc. The best approach is to decide whether to add a flow meter based on its importance.
Bias flow is very common in production; it can be caused by fluctuations in flow rate, pressure, operating conditions, and catalyst loading. The main focus is still on the stability and continuity of production
Problems with pipeline installation, low flow rates of the medium, high viscosity, and other factors can also lead to deviation in flow direction
The original poster’s question is too vague. The causes of bias currents vary depending on the situation. As far as I know, when the flow rates in the parallel branches are uneven, flow deviation occurs, as mentioned on the 2nd and 3rd floors. Additionally, flow bias can also occur in the reactor; this is manifested by a large radial temperature difference within the bed layer, resulting in substandard product. The reasons for the uneven distribution of materials inside the reactor include uneven catalyst packing and improper installation of the distribution plate.
I’ve encountered situations where, in a system with a stable operation, there was a deviation in the flow of liquefied gas, resulting in different temperatures at the two outlets; in such cases, I would shut down the outlet with the lower temperature.