A cartridge heater is a cylindrical tubular heating device that may be used to heat a wide range of materials, machinery, and equipment. A cartridge heater, unlike an immersion heater, is inserted into a hole in the item to be heated and produces internal radiant heat. They are commonly used to heat a metal block from the inside, and they may be customized to a certain watt density based on the application’s requirements.
Short History of Cartridge Heaters!
Cartridge heaters were initially made of a ceramic-supported heating wire put inside a spherical metal tube, giving them the appearance of cartridges (thus the name). They offer targeted heat to confined working areas that require precise temperature control. Their power density is less than 60 W/in2, and they produce temperatures of up to 1,200°F. They range in diameter from 1/8 to 2 inches and in length from less than an inch to more than four feet. Although they are often spherical, they can have square or rectangular cross sections. Standard heaters account for approximately 20% of all electric heaters manufactured.
Crushed heaters, created roughly 60 years ago, consist of inorganic powder finely crushed onto the heating wire. This raises their power density to approximately 500 W/in2, and their maximum temperatures reach 1,800°F. Compacted heaters cost 1.5 to 3 times as much as normal cartridges because they require higher-quality tubing and precision-fired crushable ceramics. They range in diameter from 1/8 to 1 in. and in length from 1 inch to more than 3 feet.
How are Cartridge Heaters Made?
Nickel/chromium heating coils are put into a ceramic tube within a metal housing or sheath in a typical cartridge heating device. Magnesium oxide filler is then vibrated into the hole to fill any gaps. This improves heat transmission to the metal exterior. An end cap is welded to the bottom, and insulated leads are placed on the other end. For swaged heaters, the nickel/chromium wire is coiled around a ceramic core, bringing it closer to the metal housing.
Magnesium oxide is vibrated in, and the heater is swaged to a precise size. This compresses the magnesium oxide, making it a stronger heat conductor while keeping its dielectric characteristics. This enhances heat transmission and allows for greater wattage density. Swaging also allows the heaters to function at greater temperatures and endure vibrations.
How do cartridge heaters work?
Cartridge heater manufacturers emphasize the simplicity of their heaters’ design and operations. A cartridge heating device is made out of a ceramic core wrapped with resistance wire. The core and resistance wire are wrapped in a dielectric metal sheath composed of steel or stainless steel.
Heat is delivered from the resistance wire to the sheath, then to the substance to be heated. It’s a rather straightforward technique. An alternating current heats the coil within the heater, which in turn heats the resistive wire. Conduction transports heat energy from the wire to the metal sheath and subsequently to the surrounding surroundings. Cartridge heaters are the most efficient way to transmit heat into a metal solid because the entire heat energy is transferred from the element to its surroundings.
How do you install a cartridge heater?
These heaters are offered in three wattage levels: low, medium, and high. They can withstand operating temperatures up to 1400 degrees Fahrenheit. The optimal operating temperature, however, will be decided by the application for which the heater is employed. Installing a cartridge heater incorrectly can cause several issues, including premature heating element failure.
So, take your time and ensure you get it right. It is vital to select the appropriate heater for the work and double-check that the hole you are drilling is the proper size for the heater. When using heat transfer lubricants, use caution and protect the leads as much as possible. Refer to the user manual that came with the product to get full directions for installing a cartridge heating device.
Installation Tips
Cartridge Heaters Should Not Enter The Holes
The heater can endure extremely high temperatures, but the lead wire and connection to the pin wire cannot. The lead wire on our regular heater is rated at 482°F or 842°F, depending on the power and voltage. If your leads will be exposed to temperatures above 500 degrees Fahrenheit, we recommend utilizing our configuration CB, which features ceramic beads over nickel pin wire for superior high-temperature protection.
Cartridge heaters should not extend outside of the holes.
These heaters often have greater watt densities than other types of heaters because they are installed in such a way that heat is rapidly evacuated from the heater’s surface. If your cartridge heating device extends out of the hole, only the surrounding air can remove the heat produced by the heater. Of course, metal conducts heat far better than air.
This might result in an early mortality for a cartridge heater. If you need a piece of your heater to extend beyond the border of the mounting hole, specify an unheated region at the end when ordering.
Advantages of Using Cartridge Heaters
One of the primary benefits of heaters is their quick heat-up time. Because the resistance wire has direct contact with the heated substance, it may quickly transfer heat to the surrounding environment. This makes cartridge heaters appropriate for applications that demand quick heating.
Another benefit of these heaters is their adaptability. They can heat liquids, gases, and solid objects and come in a variety of forms and sizes. This makes cartridge heating devices appropriate for a wide range of industries and applications.
Conclusion
Cartridge heaters with custom features and specifications are used for specific applications, such as heaters with crimped-on leads, swaged-in leads, stainless steel braid, stainless steel armoured cable, right-angle fiber glass leads, right-angle stainless steel braid, and right-angle stainless steel armour, among others. From composition to lead angle, every aspect of these heaters is configurable, making them very attractive in a variety of sectors.
Patel Heaters has decades of expertise in design and development, bringing a wealth of practical data and knowledge. They welcome your special needs and will develop and produce a product that matches your demanding specifications.
