6 replies to this topic

[roshimessi]

dears 

does any one have information about chemical injection quill pressure drop'

in some design practice isee that the chemical injection pressure drop is 7 barg

what is the quill ?why they considered 7bar ?

is it use for all chemical injection system or not?

 

thanks

[vishwanath]

chemcial Injection into a pipe shall be acompanied by means of injection quills located at the pipe centre line in a location of turbulent mixing.Pressure drop across the quill is normally provided by the vendor,However during feed we take prelimnary estimate of 7 Bar and design the chemical injection pump discharge presure.This 7 bar is only prelimnary estimate.Quilll is used for injecting all flowing stream.

 

Regards

Vishwanath

[ist10]

Dear all,

 

does this pressure drop of 7 bar also apply to chemical injection (sulphuric acid) into cooling tower? There is a current project in which sulphuric acid is diluted with cooling water utilizing a static mixer before being sent to cooling tower basin. The sulphuric acid line is said to have injection quills upstream of the static filter however I doubt the sulphuric acid pumps are designed with the adequate discharge pressure if this is the case with DP of injection quills.

 

Many thanks in advance

[shan]

7 bar is not minimum pressure differential for chemical injection.  You are still able to inject chemicals into the process line with 0.5 bar, 1 bar, or 2 bar pressure differential with designate injection quills to get the desired injection rates.

[ist10]

Shan,

thanks for the feedback. However, if the normal pressure drop taken for injection quills is around 7 bar as per normal design of these items, I don't think it would be possible to reach the same injection rate with 05.-1 bar pressure drop otherwise it will be senseless to specify 7 bar DP.

Regards

[shan]

If 7 bar pressure differential is specified in the injection quill data sheet for the injection rate you want, you have to have 7 bar pressure differential for the injection rate.  If 7 bar pressure differential is based on the injection line pressure minus the process line pressure, you may obtain the desired injection rate at lower pressure differential per the quill rate vs. pressure differential chart. 

[ahmadikh]

 Injection quill is used to protect the nozzle and the wall in the vicinity from corrosion.. The intention is not to contaminate the nozzle vicinity and keep the current material spec...