Protecting food grade systems from contamination

[JohnRobinsonOz]

Hi Folks,

I have a design where I'm taking liquid CO2 from a food grade tank (used for export) and installing a new tie in to a 45MPa definitely-non-food grade reactor via a high pressure cryogenic piston pump at around 36kg/min.

I'm concerned about potential reverse flows contaminating the tank. I have little confidence in standard non-return valves in this pulsating high pressure service.

Can anyone point me to a good technique for ensuring no reverse flow in a very high pressure cold (-24C) line?

Thanks for any comments in advance.
John

 

[rbcoulter]

If check valves are not appropriate, then maybe a control system that monitors feed pressure and actuates block valves when the pressure falls below certain predefined limits. Charging to the reactor would only be allowed by the control system when the pump discharge pressure exists the reactor pressure by a predefined amount. I would consider TWO block valves for added safety.