Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/14/2011 5:00 PM
Probably there is a practical limit that will depend on the apparatus used. I'd expect that cavitation at the pump will cause some nasty impeller damage. I'd expect also that you'd likely want to minimize splashing when filling an empty container. If the container is not empty then the heat of the chemical reaction that will happen will likely become the safe limiting factor. Without knowing anything about your chemical engineered system I can only suggest that you try to keep this below 341m/s.
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Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/17/2011 6:16 PM
It gets a bit complicated with carbon disulfide as it has to be transferred under a water blanket. So splashing as such isn't really the issue. I suppose turbulence would be.
I don't know how you would determine a maximum velocity, but I would be taking it very gently with carbon disulfide.
48% caustic soda is very viscous. You would need to take into account the temperature. But I suspect that the viscosity would be the controlling factor.
Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/17/2011 6:57 PM
My limited chemical experience is clearly showing. Thanks for the clarification Morrie.
Correct me again if I'm wrong but it sounds like these chemicals and concentrations are clearly into the hazardous, do not attempt this at home, industrial use only application.
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"Don't disturb my circles." translation of Archimedes last words
Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/19/2011 8:52 AM
"try to keep this below 341m/s."
OP is asking suggestions for velocity of liquid chemicals through pipes at pump suction & discharge. But it seem by oversight you gave impeller tip velocity (that to of a compressor, not pump). No problem, it will still be workable for referred application if 'hundreds digit' and 'tens digit' is removed from it.
Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/19/2011 10:31 AM
No, I did not give the impeller tip velocity. I gave a ludicrous velocity for any fluid because I felt there was clearly nowhere near enough information to make any valid answer on using these hazardous chemicals. 341 m/s is also known as Mach 1.
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"Don't disturb my circles." translation of Archimedes last words
Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/20/2011 6:34 AM
Dear sir,
CS2 is going to tank it is dip type. & the concern is flashing while transferring through line (L=350 m) as cs2 has high vapor pressure (0.6 bar @ 30Deg c).
please tell me about 341 m/sec velocity. How come this much vlocity for liquid at either pump suction or discharge.
thanks
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Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
09/21/2011 10:34 AM
About velocity I have answered at #5.
Flash loss is directly proportional to pressure differential between "liquid pressure in pipe before discharging to tank" and "tank pressure above liquid level". So, to reduce flash loss keep this differential pressure as low as possible. This can be done by selecting pump discharge pressure just high enough to transfer the required rate of liquid in to the tank. To reduce pump discharge pressure, bypassing the liquid from pump discharge to suction is not the solution because it will flash at suction. VFD may be the solution. Other possibility for low flashing is let the discharge pipe feed at tank lowest level instead of from top.
Velocity Criteria For Caustic Solution & Carbon Disulfide
Re: Velocity Criteria For Caustic Solution & Carbon Disulfide
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