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W A T L O W

Application Guide

Reference Data

Step 2: Heating of Water During the Operating Cycle

Examples of Applications

The following is the energy needed to heat the treatment water during actualoperation. Even though the customer has specified a given value, it is advis- able to check that rate with the given process parameters. From Equation 1,(Page16).Q Continued
• C
p • ∆ T3.412=(2000 lbs)
B =w
• (1.0 Btu/lb
• °F)
• (80°F)3.412 Btu/Wh= 46,890 Whwhere:w= weight of water per hour= volume
Reference Data • density =1 ft (4 gpm)
• (60 min)
• = 2000 lbs/hrC

Application Guide catalog - 7347 (

3

)

• 62.3 lbs1 ft 7.48 gal
3

)(

p = specific heat of water = 1.0 Btu/lb
• ° F ∆ T = 150°- 70°= 80°F Step 3: Heat Required to Melt or Vaporize Materials During Initial Heating Not required since the water does not change phase.Q
C = 0 Step 4: Heat Required to Melt or Vaporize Materials During Operating Cycle Not required since the water does not change phase.Q
D = 0 Step 5: Determine Thermal System Heat Losses Because polypropylene is a poor thermal conductor, we will assume it acts as an insulator, and use one inch of insulation as an equivalent value.From Equation 3D, (Page18).Q
L4 = A
• F
SL • t
e = (10,520 in
2 )
• (0.05 W/in
2 )
• (12 hrs)Q
L = 6312 Whwhere:A= exposed surface area

[]

• 2 = (36 in.
• Ï€
• 84 in.) + Ï€ (36 in.) 4 = 10,520 in
2 F
SL = surface loss factor for 1 inch insulation at ∆ T = 80°F= 0.05 W/in
2 t
e = exposure time = 12 hrs 179