Bookmark and Share


Equilibrium Temperature Calculator

Equilibrium Temperature Calculator
For Pneumatically Conveyed Product

Enter value(s), click Calculate.
Units of Measure
  Flow Specific Heat
  SCFM lb/hr
Conveying Air    0.241 
Conveyed Product    
Equilibrium Temperature    

Here are web sites with specific heat of some foods, and general solids.
If you don't find your product there, try a google search for "specific heat <your-product>".  The metric conversion is easy: 1 cal/g-°C = 1 kcal/kg-°C = 1 BTU/lb-°F! 

The equilibrium temperature is a thermodynamic limit, it's simple arithmetic.  Predicting how close a particular system will come to equilibrium is a more complicated question of heat transfer.  The heat transfer consists of two parts: conduction, which depends upon the thermal conductivity and size of the conveyed product particles and convection, which depends on the turbulence and the difference between air & product velocity. 

Systems that convey moist product with warm air are influenced by evaporative cooling.  When moist product (such as flour) is heated, it's equilibrium moisture content is lowered.  When some of the product's moisture content evaporates, it absorbs a whopping 1000 BTU per lb that to flour's 0.38 specific heat!  For this reason, systems that convey moist product with warm air have much lower equilibrium temperatures than those conveying dry product.

In general, these factors will cause a system to get closer to equilibrium: