A flexible heater is a device which can conform to the surface which requires heating. There are many varieties of flexible heaters which include silicone rubber heaters, Polyimide Film heaters, heating tapes, heating tapes with thermostats, rope heaters, wrap around tank heaters, gas cylinder heaters and custom sizes.
Silicone Flexible Heaters are rugged, reliable, accurate, and moisture and chemical-resistant. They can be easily bonded or adhered to other system parts. These heating elements have a wide range of industrial, commercial, and military applictions where reliability, cost of effectiveness, minimum cross section, resistance to deterioration and basic flexibility are critical.
Learn more about Flexible Heaters
Ohm's law shows the relationship between voltage, wattage, amperage, and resistance. It is important to know Ohm's law in order to calculate the load you will be switching with your thermostat or digital controller. For example if you select a flexible heater which is rated 200 Watts and apply 120 Vac, the current will be 1.6 Amps.
A is equal to W / V where: A = Amperes; W = Wattage; V = Voltage
Using our example above 200 Watts/120 Vac = 1.6 Amps
Some other variation of Ohm's Law:
Volts = Watts/Amperes
Volts = Amperes x OHMS
OHMS = Volts/Amperes
Amperes = Volts/OHMS
Watts = Volts x Amperes
To determine the kW required to be heat up a solid. The following formula is used.
kW = (WT x Cpx Δ T)/3412 x h
WT= Weight of Material, lbs
Cp=specific heat, BTU/lb-°F
Δ T = Temperature Rise, °F
3412= Conversion Factor, BTU/kWh
h = heat-up time, hrs
Frequently Asked Questions
Temperature Controllers and Sensors for Flexible Heaters
There are a variety of temperature controllers and sensors one can use depending on the application. One of the more popular sensor types for flexible heater applications are the surface mount temperature sensors. Thermocouple, RTD or Thermistors are available with an adhesive backing or the ability to be cemented to the surface being heated. There also bolt on and magnetic surface mount type temperature sensors available. Digital temperature controllers come in many different sizes with many output and input choices. Thermcouple and RTD inputs are the most popular with a mechanical relay or dc pulse output. DC pulse ouputs allow the user to go to a larger relay to switch the heater load. Thermostats are also available for the most basic applications.
Flexible heater selection
- How much wattage is required?
- What voltage will be used?
- If it is a flat surface, what size will be needed?
- How long do the heater leads need to be?
- Will you require a thermostat or a digital controller with sensor?
- What is maximum temperature?
- For flat surfaces will require wire wound or etch foil?
- What is the time required to reach your temperature?
- What is the ambient temperature?
- Is insulation being used?