2 replies to this topic

[Sbyrne1984]

Hi All,

 

We have recently installed flow sensors into our cleaning system which uses a mix of two chemicals , one with a specific gravity of 1.51 the other is 0.83.

 

The heavier solvent has a lower boiling point and when heated mixes through the lighter liquid creating a churning mix. This is then pumped through a filter constantly for cleaning.

 

The heavier liquid also evaporates over time so the mix constantly changes.

 

We have noticed that as the heavier liquid evaporates the flow rate through the filter increases. 

 

My question is what is causing this?

 

Is it ;

1. Due to the reducing density of the Mix (as the heavier liquid evaporates) the relative head of liquid increases and flow increases as a result? 

Or

      2. The lighter liquid is easier to pump and hence flow increases?

 

Not sure if either of these is the case??

 

 

[latexman]

Viscosity differences?  Are you measuring mass or volumetric flow?  Is the pump centrifugal or PD?

[Sbyrne1984]

kinematic viscosity of Heavier fluid is 0.77 cst, lighter fluid is 2.65.

 

Volumetric flow rate through a centrifugal pump,