Issues with the control valve for returning catalytic cycle slurry to the tower.
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This post was last edited by lijianhuai on 2011-3-4 08:58. The circulating slurry returns to the distillation tower via two paths. However, during the design phase, the design team provided only one control valve for the flow returning to the tower, and the pipeline for the flow returning upward is thinner. Is this a viable solution? Could there be deviation in the flow or imperfect regulation? ?
Because as long as the total circulation volume of the slurry remains constant, adjusting the flow rate of the slurry returning to the tower – by increasing or decreasing it – will correspondingly affect the flow rate of the slurry going back up to the tower; after all, it’s one outlet with two streams
From a normal design perspective, adjustments and operations are no problem; however, under abnormal operating conditions, fluctuations are significant. In particular, issues with heat extraction in the slurry system lead to large fluctuations in the bottom temperature of the tower, which remains high.
I also think that it works fine when used normally, but with this design it’s not possible to reach the maximum flow rate; however, the maximum value is generally not needed either, so it’s hard to say.
Reply to 1# Chuan Nao Liao Kun: The circulating slurry returns to the distillation tower via two paths, and only one downflow control valve is provided for these two paths; this might work. But the pipeline returning to the tower is a bit thinner, and I’m worried about some issues – is the flow rate sufficient for returning to the tower? As the flow rate in the pipeline increases, so does wear; will the material of the pipeline be sufficient to meet the requirements? Two streams of oil slurry return to the tower, with emphasis placed on maintaining the volume of flow going upward into the tower, in order to ensure effective washing of the catalyst in the oil and gas. What if the amount of material returning to the tower is not enough? Especially when the pump cannot deliver enough flow, it can cause the catalyst to be carried up to the upper trays, with serious consequences.
Our unit’s design involves two control valves, and the amount of material returning to the upper tower is more than 2.5 times that returning to the lower tower~~~