[BikerBill]

I did a copy and paste from the powder coating book that is in the sticky notes..

It is a bit much to read, but look this over figure what you think your heaviest parts would be and go from there... I never bothered to check but I bet there would be a big differance over what the home heating calc says you need.

Again, I would love to see this in excell.. Im not good at it or I would make my own spread sheet, but is someone here is I would be glad to work any of the formulas out with them to make a copy avalable to put here.


Formula: Sq. Ft. of Oven Surface x Panel Loss Factor x Temp. Rise
Example:
Oven Size: 20’0” W x 50’0” L x 10’0” H
Operating Temperature: 300 °F
Oven Start-up Temperature: 70 °F
Panel Thickness: 4”
determine sq. ft of oven surface
sides: 10 x 50 = 500 x 2 sides = 1,000
ends: 10 x 20 = 200 x 2 ends = 400
top & bottom: 20 x 50 = 1,000 x 2 = 2,000
add all surfaces: 1,000 + 400 + 2,000 = 3,400 sq.ft
find panel loss factor from table 11-1
(.35)
determine temp. rise in degrees F
300 – 70 = 230
calculate panel loss factor
3,400 ft2 x .35 panel loss factor x 230 temp. rise = 273,700 Btu’s
Product Loading
To calculate the Btu’s required to maintain the set temperature in
production, multiply the total load, (parts, rack, conveyor chain and
trolleys), Table 11-2 x 0.12 (Btu’s required per lb.°F) x temperature
rise. The factor 0.12 is used for steel. Different materials will require a
different multiplier. Table 11-3 shows the specific heat value for different
metals.
Panel Thickness Loss Factor
3" .40
4" .35
5" .30
6" .25
8" .20
Table 11-1 – Panel Loss Factor
XI
Powder Coater’s Manual 1/98 XI /5
Chain Weight
Conveyor per Foot Trolley Weight
Enclosed Track 3.50 lbs. .5 lbs (H-Attach)
X348 2.14 lbs. 2.34 lbs.
X458 3.14 lbs. 5.18 lbs.
X678 6.39 lbs. 16.50 lbs.
Gas Use in Btu’s
Example:
Chain - X348
Trolley Centers 12”
Racks - 5 lbs. on 12” centers
Parts - 5 lbs. on 12” centers
Line Speed - 10 FPM
Oven Temp. - 300 °F
Oven Start-up Temp. –70 °F
determine chain lbs./ft.
2.14 + 2.34 = 4.48 lbs./ft.
determine part & rack load
5 + 5 = 10 lbs./ft.
determine total load
4.48 lbs. chain & trolleys + 10 lbs. part & racks = 14.48 lbs./ft.
Table 11-2 – Chain & Trolley Weights
Table 11-3 – Specific Heat of Different Metals
Metal Specific Heat
Steel 0.120
Aluminum 0.226
Iron 0.175
Zinc 0.0931
XI
XI /6 Powder Coater’s Manual 1/98
Gas Use in Btu’s
determine total product load/min.
14.48 lbs./ft x 10 feet per minute = 144.8 lbs. per min.
determine product load/hour
144.8 lbs. per min. x 60 mins. = 8,688 lbs./hour
determine temp. rise
300 – 70 = 230
calculate Btu’s
8,688 lbs./hr. x .12 Btu’s x 2300 temp. rise = 239,789 Btu’s
The parts that are processed may not be made of steel and
may require a different factor from the list on page XI/3.
Exhaust Loss
The exhaust loss is determined by multiplying the cubic feet per minute
of exhaust (CFM) x 60 minutes x 0.075 pounds per cubic foot x .24
Btu’s per pound °F x Temp. rise.
Formula: CFM x 60 x 0.075 x 0.24 x Temp. Rise
Example:
Exhaust Volume: 2,000 CFM
Set Temperature: 300 °F
Oven Start Temp.: 70 °F
determine temp. rise
300 – 70 = 230
calculate exhaust loss
2,000 x 60 x .075 x .24 x 230 = 496,800 Btu’s
• 0.075 is the density in lbs. of standard air
• 0.24 is the specific heat of air
To determine the total Btu’s consumed, add a, b and c. In the above
examples this total would be:
273,700 + 239,789 + 496,800 = 1,010,289 Btu’s