Reynolds and Velocity_Clean Utilities in Pharmaceutical Industries

[Luisa89]

Dear all,
sorry for bothering you again. Please, could you help me about the value of clean utilities velocity in Pharmaceutical Industries, according to the normatives. Sorry, I don't know how specifical normative reports this value. It is necessary to ensure turbolent regime in order to avoid biofilm. Is it possibile the velocity could be 2,5 m/s?

Thank you so much for your help.
Best regards,
Luisa

 

[EdStainless]

Most CIP systems that I have seen aim for a flow that is 30-50% higher than the usual process.
I have seen CIP run as high as 3.5m/s.
The velocity itself will not really strip biofilms.
It will remove some if they are dead, but they use foaming cleaners if that is a real issue.

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P.E. Metallurgy, consulting work welcomed

 

[jari001]

Is this in reference to a water for injection system? 2.5 m/s is on the higher end of velocities used for such a water system, but it's not unreasonable. Keep in mind that it's recommended that the Reynolds number be well within the turbulent regime for the water system (at least >10000) and not just at or slightly above 4000.

 

[bimr]

Distribution System should have turbulent flow with nominal velocity in the range of 1 – 3 m/s.

Distribution systems shall be of the constantly circulating type, designed to minimize bacterial colonization. A minimum velocity corresponding with turbulence Reynolds Number (Re) of not less than 10,000 is required throughout the system under all conditions, including peak design demand. Stainless steel distribution systems shall provide a velocity of at least 2 FPS under normal conditions. Systems shall be capable of achieving elevated velocities for systems sanitization of 3 to 6 FPS for PVDF, PVC, and Polypropylene materials, and between 3 and 8 FPS for stainless steel piping. This may be readily accomplished with VFD pumps or design to the elevated criteria. Pumps shall be sized and calculations demonstrate that sufficient supply to demand ratio flow rate is provided that under all demand conditions velocity will not drop below the required minimum and the required minimum supply loop pressure will be maintained throughout the system, and to ensure that tanks are turned over completely not less than once in a 24 hour period. The A/E may, at their option provide for normal operation at system velocities of 3 to 5 FPS. Pumps shall be arranged to preclude dead zones and if not constant running, shall at least be operated daily.

 

[Luisa89]

Dear all,
thank you so much for the useful answers and for all you help. Now it is very clear.

Regards,
Luisa