Chemical dosing slugs

[Fence12]

Hi,
I am having a problem with slugs when starting a chemical dosing pump. Once flow is established
the system behaves normally which normally occurs after about 5 to 6 strokes. The issue is that
an unacceptable level of chemical is introduced for a short period of time.

The dosing pump is about 400m away from the injection point where it is mixed with carrier water
before injecting into the mains.The system also has a degassing line which activates each time the pump
starts. Have tried initial lower and higher dosing rates but no change. Any suggestions would be appreciated.

 

[Latexman]

A P&ID with elevation correctness may be helpful.

Good luck,
Latexman

Need help writing a question or understanding a reply? forum1529

 

[Compositepro]

A system with a metering pump 400 meters from the injection point is rarely likely to work well. There are many sources of variation and you've told us almost nothing. One of the biggest factors is how accurate do you want to be? Others are: Thermal expansion of the pipe and liquid inside, air bubbles trapped at high spots, and system pressure variation.

 

[bimr]

As Compositepro suggests, it is not practical to pump 400 meters with a low flow chemical feed pump and small diameter piping system. That is the reason that carrier water systems are used.

Pipe the carrier water system to within 2 meters of the chemical feed pump and you will solve your chemical pumping issues.

 

[Tipp2239]

Inject mire ewater for a short time at the start then reduce back, You may need two water pumps?