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Vessel offload - increase throughput/bph

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MidstreamEgr

Mechanical
Feb 6, 2012
23
I have a existing terminal with dock, currently offloading at ~1600bph thru a 8" line to existing tankage. I'm looking for a way to increase throughput to reduce demurrage and overall product throughput. My limitation is the ~100psig max at the vessel's connection, so flowrate is effectively limited by how much pressure drop is in the line from dock to tank.

Are there any ways to boost throughput on the line itself? Add a "booster pump" inline about 1/2 way along line to allow a greater overall pressure drop? Increasing line size is unlikely, given the restrictions (right of ways thru others property, long distance, etc). Same problem for adding a second "sister" line and running them in parallel.

Thanks
 
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Generally increasing velocity of flow at a shipping terminal would not be the ideal solution. The existing pipe is low pressure, mass flow rates are high, plus there are are too many temporary connections around to deal with waterhammer transient pressures in a high risk area.

Loop the line, piggy-back "8" style, with another 8" on top?

If it ain't broke, don't fix it. If it's not safe ... make it that way.
 
In order to increase flow, you would have to review/redesign the entire existing piping system for the pipe stress associated with your new process requirements. You will have also have to review the vessel's pumping system and venting system.

Bumping the pipe diameter up probably would make more sense. You can get 50% more capacity just going to a 10-Inch pipe.
 
Pressure drop thru' the pipeline is D1/D2^5 for the same flow rate however, reducing the head on the pump by changing pipe diameter may increase the flow rate but without having all datas available there is no way to predict what that flow rate could / might be.

As any change to the pipeline seems unlikely, and if all ready pumping at 100psi at the connection, a second pump at some point along the pipeline seems the only alternate. But as mentioned above, reducing the pump head on the first unit will change the flow rate and the head loss by an unknow amount - therefore a full study of the system using 2 pumps is required along with a cost benefit analysis before any major changes are considered.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
 
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