Investigating and resolving low flow rate within a system

[JoeyX]

I'm a recent graduate working for a chemical facility and would appreciate some insight on this problem


I have a solvent being transferred from an IBC to a reactor (reactor 1). This transfer was found to be operating at a low flow rate of 1.5L/min. The designed flowrate is as 60L/min, how you would look at investigating and resolving the low flow issue?

Schematic -

https://i.imgur.com/AeR0WBx.png

Ideas for thought:
- the possibility that the solvent in IBC is not the correct fluid

- 1st thing I can suggest is its possible your pump isn't strong enough; this could be due to the design of the system (NPSHr > NPSHa which would cause excessive cavitation and degradation of pump performance. If this was the fault, the pump could be an element to be investigated.

- Potential fault in the compressed air line to the pump, reducing the performance in mass transfer. Can be identified by the pressure gauge.

- Assuming reactor 2 and 3 achieved the designed flow rates, it would seem there is an issue with the pipe following reactor 2. This could be investigated by inspecting the pipe for any leaks/damage. Likewise, perhaps there is an issue with one or both of the actuated valves after reactor 2.

Are there any other possible faults or points that I could expand on?

 

[3DDave]

I'd start with the design documentation and check that work.

 

[Compositepro]

I guess we all must start learning at some point, but this is really basic troubleshooting/problem solving. Your fourth point is logically jarring in that, if it is the case that reactor one is differing from 2 & 3, then all your other points are instantly eliminated as causes. So why did you waste our time with those?

Have you actually seen this problem or is this an abstract exercise given to you by your supervisor as a test? Do you know what an AODD pump is and how it works? If the outlet of the pump is restricted it will slow or stall. If the inlet is restricted it will stroke rapidly without pumping. You can easily see and hear these things.

 

[LittleInch]

Different pressures in the reactors?

First thing is to work out what should be happening and if it ever worked.

If it did then did anything change?

Does it flow to all three reactors at the same time?

Is there any flow control to the other two?

What is the flow rate from the pump?

"Assuming reactor 2..." Don't assume anything - check.

Blockages are more likely than leaks or damage

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JoeyX]

Thanks for the help guys

 

[JoeyX]

@Compositepro, why would the points be dismissed, is it not possible that the pipework concerning reactor 1 is at fault?

 

[Compositepro]

All the other points you mention would cause problems with all three reactors, not just one.

 

[JoeyX]

@Compositepro thank you for the insight, apologises I didn't make it clear that the 4th point would in fact be independent to the other points.