Explosion-proof heaters are potentially life-saving equipment for industrial settings threatened by fire hazards. But for these heaters to function as required, they need heating elements that provide sufficient power without overheating. Enter tubular heating elements. These components can service explosion-proof heaters in this regard, and this post will examine how they can do so.
Explosion-proof heaters provide high-temperature heating in facilities where flammable substances are present. Environments of this sort are known as hazardous locations, which fall under one of three classifications. These environments include the likes of aircraft hangers, oil drilling rigs, sewage treatment plants, petrochemical plants, and more.
Flammable substances in these environments may include gases, dust, or fibres that can spark and ignite if exposed to high temperatures. Herein lies a problem. These applications often require high temperatures, some as high as 650C (1200F), to produce viable end-products.
This is well beyond the ignition point for many flammable substances. Traditional open coil elements increase fire risks because they are directly exposed to flammable substances.
Tubular and finned tubular heating elements offer a middle ground between performance and safety. Here at Wattco, our tubular and finned heating elements produce high temperatures reaching an upper limit of 700C (1292F) using a relatively low watt density. That makes them suitable for almost all hazardous locations.
They come wrapped in a sheath that protects coils from physical stress and sparks that could ignite a fire. If necessary, we encase these elements in a NEMA 7 box so the terminal doesn’t come in contact with flammable substances.
A heating element’s temperature is just one factor of consideration when buying explosion-proof heaters. Safety takes precedence with these heaters, and that’s why tubular elements come with additional features to prevent ignitions.
Proximity is a two-fold issue when it comes to safety. First, a spark can occur if the element is too close to the terminal, which would invariably ignite certain substances (assuming the temperature is high enough). That’s why it’s vital to put a distancing section between the terminal and the element, known as the “cold section.” Generally speaking, the higher the applied temperature, the longer the cold section will be, although there are exceptions to this “rule.”
Proximity also matters when attaching a thermocouple to a tubular heating element. The role of the thermocouple is to sense the temperature generated by the heating element, which then provides a temperature reading. Excessive distance may delay temperature readings, leading to overheating and potential fire if operators don’t know to shut the system down.
Fortunately, our tubular heaters are built to maximize safety. The strength of their safety protocols comes from how we design your application’s elements. We consider your application’s requirements— the required temperature ranges, hazardous substances that may be present, and the necessary dimensions of your heater.
That helps us determine the needed diameter and shape of your tubular elements, along with the type of materials needed for the sheath. For example, we will alter the shapes to limit excess bending, as this could also lead to equipment failure. Additionally, we place the cold section of your heater elements at an appropriate distance from the terminals and your thermocouples in the best position for your element. Our calculations and design will ensure your explosion-proof heater excels at safety and performance.
Operators in hazardous locations can reduce the risk of explosions using various approaches. That may include ramping up containment and ventilation or maintaining process equipment under negative pressure. An explosion-proof heater is just one measure to keep explosion risks low, but these containment methods can be used alongside an explosion-proof heater. We will cover these methods in a subsequent post.
Of course, if you need an explosion-proof heater, we will build a unit to match your unique requirements. Here at Wattco, we provide customizable explosion-proof heaters equipped with tubular heating elements that can meet your industrial requirements. Whether you’re working with highly reactive gasses or flammable fibers, we will construct a unit that keeps your staff safe.
Get a quote for your explosion-proof and tubular heating elements today. Our representatives will help you find the exact setup needed for your industrial needs.