1 reply to this topic

[asmsyn]

HI...

I have been given a assignment for designing a scrubber(Packed ,random packing) for scruubing vent gases coming from scrubber.

Thr are dedicated storage facilities for Aq. wastes and organic wastes.
All organic wastes are under N2 pressure padding(30 mbarg) setting.

Now to decide on the load..1) for organic i have considered displacement volume of air(eq) during pumping- in of liquids.
2) similarly for Aq. storage tanks also. now Aq. storages are of RCC construction(Rectangular) and definate chances of air leaks.

So i wanted to know how to calculate the load(flow rate) due to air leak in the system, if scrubber pull to be adjusted at -10to -15 mbarg.

Thanks

[proinwv]

If I am to understand you correctly you are saying that your tank is/will leak. The amount of leakage is a function of the pressure differential, and the "leakage orifice" which is probably of undetermined size and shape.

First, unless this is a very small vessel, I do not believe that the actual leakage rate can be measured.

Second, our goal is to have a tight tank. One should always work to seal off a tank for such service. Dependent upon the size of the tank and location, and taking into account the safety of the technicians, there are means to check a tank. One being using a leak detector and lightly pressurizing the tank. However, the leakage out, might be different than the leakage in. But that is another subject. For some tanks the configuration itself would make it dangerous to measure the leakage.

I started to write of methods to take a wild guess at leakage rates and then deleted that. I cannot recommend such guessing methods to the operation of a supposedly sealed tank.

This is a continuing issue with tanks. Operators do not know the tank ratings and do not keep the tanks leak free. This is not acceptable practice for a tank that is to be sealed. You should know that rectangular tanks are poor candidates for pressure/vacuum service and present their own design challenges.