FSN 204 Lecture Notes - Lecture 5: Unit Operation, Extrusion
11 Feb 2018
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Document Summary
A mass balance, also called a material balance, is basically: what goes in must come out. Matter can not be created or destroyed: mass of all the ingredients that go into a unit operation must be accounted for by what comes out plus what may hang up inside what is doing the operation. The mass balance helps see how the system is operating so waste can be minimized. Allows calculation of system efficiencies and can help identify possible areas of improvement. All mass carries energy so this will be critical when moving on to energy balances. Ingredients x lbs (12% moisture: w lbs of water. Output: product 2,500 lbs (22% moisture) Total mass balance: x lbs + w lbs = 2,500 lbs. Solids balance: (1-0. 12)x + (0)w = (1-0. 22)(2,500lbs: 0. 88x = 0. 78(2,500lbs. , 0. 88x = 1,950lbs, x = 2,216lbs of ingredients, w = 2,500 2,216 = 284lbs water (or 34 gallons)
