The size of the safety factor is dependent on the accuracy of the wattage calculation.
Cartridge heater watt calculation.
Thus for a 1 2 x 12 heater rated 1000 watts the watt density calculation would be as follows.
Standard air is 70 degf 14 psi scfm stands for standard cubic feet per minute and delta t exit temperature minus inlet temperature in degrees fahrenheit.
Heat calculations watt density for cartridge heaters other heater applications.
Kw w x c x t w weight of material in lbs.
For example a 1 2 x 12 cir heater rated 1000 watts has a watt density of 55 w in2.
So the formula for calculating heat loss due to radiation is.
How to calculate required wattage.
Watt density w p x d x hl.
For calcualation purposes stock cartridge heaters have a 1 4 unheated length at each end.
20 additional wattage is more common.
Heaters should always be sized for a higher value than the calculated figure.
A factor of 10 is adequate for small systems that are closely calculated.
Cartridge heaters electric insertion heaters immersion heaters square metric imperial cartridge heaters technology for industry toll free.
The first thing to know is how many pounds of air need to be heated.
Suppose you wanted to calculate the radiation loss.
For calculation purposes cir stock cartridge heaters have 1 4 unheated length at each end.
In order to determine whether a particular heater will perform well in your application you must compare its wattage with your requirements.
Manual calculation of total heat requirements for insertion heaters applications.
L radiation radiation loss w in 2 x area x emissivity x 1 hr for example assume the tin block has a radiation loss of 1 1 w in 2 and an emissivity of 0 04.
Kw wt x cp x δ t 3412 x h where.
Kw scfm x delta t 3000 x 1 2 this formula can be used for standard air.
Watt density w π x d x hl.
You can use the following formula to determine your required wattage.
It is the number of watts per square inch of heated surface area.
Follow the formula in this video given by chet omega engineer to understand exactly the type of surfac.
Kw your kilowatt requirement.
Thus for a 1 2 x 12 heater rated 1 000 watts the watt density calculation would be as follows.
