PTC Element Improves Cartridge Heater Efficiency
New PTC ceramic heating elements improve the efficiency of typical resistive heating elements used in immersible applications where optimal heat transfer is required.
The PTC, Positive Temperature Coefficient, the heating element is built into exceptionally corrosive resistant stainless steel casing. Unlike the picture of a resistive element without protective casing.
The compact & robust circular provides 360° heat transfer. The PTC functionality is self-regulating and will not overheat.
Cartridge heaters are often confused with tubular heaters. A cartridge heater is designed to be inserted into a die or vessel wall by screw mount.
Tubular heaters can have more complex geometries and may be welded or permanently attached or clamped to a vessel requiring heating.
Both types of heaters usually contain electrical resistance heating elements insulated from the surface of the heater. PTC ceramic heating elements are self-limiting and voltage self-insulating, providing more efficient heat transfer.
In any heating application, some form of energy, electrical, gas, oil, or even hydropower is being converted into heat. The energy of one is converted to heat energy which in turn raises the temperature of the adjoining air or physical object to bring both into equilibrium.
A PTC element cartridge component converts electrical energy through the resistive element to heat which transfers very effectively to the aluminum housing. The circular stainless steel housing is designed to transfer heat directly to the surrounding surface or liquid.
Due to the compact size of these heating elements and power density, the energy transfer is more efficient than many other types of heating elements. The PTC elements draw more power initially due to lower resistance and heat faster but lower power as the element reaches equilibrium with the adjoining space.
PTC elements are valued because of the relationship between temperature and the resistance of the circuit. As the temperature increases the resistance of the circuit increases. This relationship is described as a Positive Temperature Coefficient.
More importantly, there is no risk of overheating due to the characteristics of the positive temperature coefficient PTC heaters. The fan heaters have a set power input and self-limiting temperature.
Applications for PTC Element Cartridge Heating
DBK’s EHS series of PTC cartridge heaters have temperature ranges up to 400° makes them effective for many industrial processes to maintain optimal process temperatures.
- Plastic molding
- Heating gases & liquids
- Hot stamping
- Packaging equipment
- Injection molding
- Hot melt adhesives
- Fluid heating
The small sizes from 10mm in diameter and 55mm long make them ideal for compact medical equipment maintaining the internal temperature of liquids or lab processes.
Benefits of PTC Cartridge Heating Devices
Self Regulation & Safety
PTC heating elements are temperature and current self-regulating. Each PTC ceramic element is manufactured to a specific temperature. Once the device reaches that temperature the inverse nature of the device increases resistance in the circuit to infinity effectively shutting down the circuit.
The temperature is relative to an ambient temperature such that at high ambient temperatures less current flows in the circuit to reach the set-temperature without external controls. The self-regulating nature protects the device from over-temperature and current.
Compact & Durable for Tough Applications
Traditional PTC cartridge heating elements utilizing electrical resistive heating elements and control circuitry often making them unsuitable for applications with limited space. PTC ceramic elements are embedded into tubular stainless steel casings. The extended life of the PTC ceramic elements compare to resistive wire and the casing make them ideal for corrosive environments. Longer life is fewer maintenance costs and downtime.
PTC Element Efficiency
The Positive Temperature Coefficient element controls the resistance of the circuit to a specifically designed point. The warmer the element the higher the resistance. The cooler the element the lower the resistance and more current will flow increasing the heat.
These characteristics save energy and prevent excessive heating losses.
Voltages, Power, and Dimensions of ESH Series Cartridge Heaters
Cartridge heaters with PTC ceramic heating elements support multiple voltages; 12V & 24V and 110V & 240V. Power ranges and temperatures are provided in the specification sheets.
High Power Density
These devices have a higher power density than resistive wire heaters. The small size of the PTC ceramic heating elements and the ability to be embedded directly into materials for efficient heat transfer results in concentrated power density.
How do you size a PTC immersion cartridge-type heater?
Some PTC heating devices are sized by reference temperature, the maximum temperature of the device before the resistance stops current flow. Some are sized by power output. Max inrush current is defined for each power rating for circuit design purposes.
This heater type is often dependent on the size of the vessel opening or diameter of the vessel.
DBK USA has experts standing by to answer your questions. Design engineers can utilize the handing power calculator on our website.
Feel free to call our thermal engineering specialists directly at 1-864-607-9047. Go to our resources page for more information on PTC convection heaters.