Heater Specs for Heating Cylinder to 200°C - Dimensions, Wattage & Length

[abhipatel]

Need to heat a cylinder (hollow one) till 200 C...dimensions of cylinder are

OD = 5.9" ; ID = 2.54"; Height = 6.4"

"Rope heater" specs available are 120 V, 125/250/400 Watts and 3ft/6ft/9ft length; Linear Wattage = 4 Watts/in and dia. of heater = 5 mm (3/16").

brain is fused ;)...just cannot seem to get around and calculate:

1. Length & wattage required
2. what combination to use? I mean 250 W and 6 ft or take max @ 400 W & 9 ft...cannot seem to justify it manually?

Please guide me here

 

[Navin A S]

.To answer your questions, you need to calculate the total surface area of the cylinder and the total wattage needed to heat it to 200 C. The formula for the surface area of a hollow cylinder is: Surface Area = 2πr(h + R) where r is the inner radius and R is the outer radius of the cylinder. In this case, the inner radius is 1.27 inches (2.54/2) and the outer radius is 2.95 inches (5.9/2). The height of the cylinder is 6.4 inches. Plugging this into the formula above, we get:Surface Area = 2π(1.27)(6.4 + 2.95) = 57.72 in2 Now that we know the total surface area, we can calculate the total wattage needed to heat the cylinder to 200 C. Assuming an average temperature of 100 C, we can use the following formula to calculate the wattage: Wattage = Surface Area x (Temperature Difference / Insulation Thickness) Assuming a standard insulation thickness of 0.5 inches, we get: Wattage = 57.72 in2 x (100 C / 0.5 in) = 11,544 Watts To determine the length and wattage of rope heater needed to heat the cylinder, we must first determine how much wattage each foot of rope heater will generate. From the specs given, the linear wattage of the rope heater is 4 Watts per inch. Since there are 12 inches in a foot, this means that each foot of rope heater will generate 48 Watts (12 x 4). We can then calculate the total length of rope heater needed by dividing the total wattage required by the wattage of the rope heater: Total Length = 11,544 Watts / 48 Watts/foot = 240 feet Finally, we can calculate the wattage of the rope heater needed by multiplying the total length by the wattage per foot: Wattage = 240 feet x 48 Watts/foot = 11,520 Watts Therefore, you would need a rope heater with a watt