I need to design and commission a system to feed ingredients to a mixer. The ingredients are selected surfactants in liquid form and water in amounts from 50 to 800 kg.

What do my fellow engineers think is the best method?
To usse intermediate containers, pumps and a balance with 1000 kg capacity; or a pump and a volume counter, transferring directly from storage containers to mixer?

Hi Fabio,
As far as mixing liquid surfactant in water is concerned, using a pump and volume counter is more convenient than measuring the mass.

So I think I will go the volume counter way. To be on the safe side I think I'll calibrate them against weight erogated tho.

That will be nice.

I wouldn't go cheep and assuming the batch system being discussed I would prefer the volumetric integrating flow meter (counter) for water and load cell (scale) for surfactant.

Volume counter for water; drum factory-filled by weight with 0.5% tolerance for one surfactant and scale for another surfactant. That seems tight enough.

Va bene.

Volumetric measurements may be more suitable if you are very concerned about error issues but you may opt for finding the density of your components in view of your measurements if you have components that readily change in state quite qucickly ,with the use of the relative density/specific gravity too you may still go the volumetric route, this is my guess, I stand to be corrected if I am wrong.

Mass flow meters are available with control system. Once you enter the density of the fluid being dealt, to the system, it will give you the exact amount of mass transferred and mass flow rate.

Mass flow meters are in general easier to work in day to day. Mass doesn't variate with temperature this may avoid problems with time.

Volumetric measurement varies with temperature. I recommend to use load cells to measure the amount of the ingredients. Either the batch tank or a common ingredient receiver (smaller, more accurate) can be equipped with such load cells.