We know that 100 degrees is enough for water, and about 300 degrees is the limit for oil.
So how many degrees can a air heater element heat up to? This is not easy to determine the limit temperature, because its heating medium is air, and air specifically impedes heat conduction. So in the analysis of the heating degree for air heater element ,it is not determined by the limit temperature of heating medium, but is the tubular air heater"surface load", what is the surface load, and how to calculate the surface load,what is the relationship between the surface load and air heater element?
1.Surface load
Surface load refers to the equal distribution of power over heating tubes per square centimeter of area.
How to calculate the surface load: first calculate the size area of heating tube =3.14* tube diameter * length (in centimeters), and then the power/side area is the surface load.
Ex. :
The diameter of the cartridge heater is 12mm, the length of the tube is 500mm, the length of the heating zone is 450mm, and the power is 676W. How much is its surface load?
Lateral area = 3.14 * 1.2 * 45 material 169 cm2
Surface load = 676W /169cm2= 4W /cm2
So the surface load of this heating tube is 4W /cm2.
2. Temperature relationship between surface load and air heater element (surface temperature of electric heating element in non-vacuum state)
Surface load 1W/ C ㎡, surface temperature can reach 300 degrees;
Surface load 2W/ C ㎡, surface temperature can reach 400 degrees;
Surface load 3W/ C ㎡, surface temperature can reach 500 degrees;
Surface load 4W/ C ㎡, surface temperature can reach 580 degrees;
It should be noted that when the surface temperature of the heating tube reaches more than 400 degrees, the surface of tubular air heater will be red.
When the surface load of the air heater element is large enough, the surface temperature of the heater element can reach more than 1000 degrees. If there is no temperature control, the temperature of the heating element will continue to rise until the resistance wire and tube shell can not withstand such a high temperature and burn out.
So when someone asks how many degree can air heater element be heated to , it is necessary to see how much is the surface load.
