by Rebekah Fuller, Editor for IQS
We rely on electric heaters to warm our homes, offices, water and food, and manufacturers depend on electric heating for numerous industrial processes, such as plastic and rubber injection molding, packaging heat sealing and die casting. All electric heater appliances contain some form of heating element that acts as a resistor to convert the energy of an electrical current into heat. The heater can be as simple as the resistor welded or brazed into a metal flange or plug that contains an electrical terminal, or a number of resistors could be bundled together inside a larger unit.
Due to the obvious hazards of bodily burns and fire damage, proper precautions need to be taken when using any kind of electric heater. A story on the news in my hometown just this winter told of a family – a single mom scraping by with two little children, all living with the grandparents, I believe – whose electricity was shut off because they couldn’t pay. The mom had purchased an electric space heater for the children’s room that ended up causing a fire killing both the little girl and boy. Combustible material – clothes, drapes, or a blanket maybe – got too close to the heater.
This tragedy is not at all uncommon. The National Fire Protection Agency reports that the No. 1 cause of home fires December through February is heating equipment, such as portable space heaters, and it’s the No. 2 cause annually. Improper use is definitely a factor, but malfunctions could happen too. You just have to Google “electric heater recall” to get page after page of results, such as overheating and melting of its plastic components.
Proper manufacturer product testing and user respect needs to go along with the use of heat energy. This energy can be transferred to the substance or area to be warmed either through the air with fans and possibly duct work, or through direct or near-direct contact. Tubular heaters, strip heaters, ceramic heaters, cartridge heaters and immersion heaters all come in close proximity to what they are heating. Sometimes they are actually attached to it or within it, as with immersion. In these instances, it is crucial for manufacturers to utilize the appropriate sheath material to cover the heating element. Otherwise, they could very well end up shocking their consumers, and not in a good way.
This year at the beginning of March reports came out about a recall of the Ritchie Immersion Heaters manufactured by Springfield Wire which were intended to keep cattle trough water from freezing; however, the heater element covering is likely to crack, based on 44 reported incidents, and cause a shock hazard.
Besides eliminating safety hazards, manufacturers who want to remain competitive must continuously develop the most efficient and effective heaters for various applications, utilizing the most appropriate materials and configurations for each use. Strip heaters are about an inch wide and very thin; they are a sheet of coated steel folded around a resistance element that is wound around and sandwiched in between an insulating element such as mica. They are mounted directly to the heat receivers, frequently metal parts, such as dies and platens.
Tubular heaters are usually used in immersion applications within a tank, pressure vessel, or pipe to heat water, oils, solvents and process solutions as well as air and gases. Due to potential hazards, if the sheath material fails, heating element protection is a must. Copper is used for drinking water; steel is good for hydraulic oils; stainless steel is ideal for mild acids; and Incoloy is great for alkaline solutions and high temperature air and gases. Plus, the immersion heaters’ electrical terminals need proper NEMA electronic enclosures, whether conditions call for heaters to be general purpose, moisture resistant or explosion proof.
Cartridge heaters are compact and cylindrically shaped to fit in bores of machines, process equipment and systems that rely on heat energy, such as copiers, the plates of injection molding presses, die casting machines, heat sealers, and certain medical equipment and food processing machinery. Choose a manufacturer that offers anti-seize cartridge heaters so they don’t adhere to the bores, reducing the risk of expensive downtime and damages.
Whether you are a manufacturer looking for the most effective and efficient heater to improve the quality and output of your machines, systems or processes, or you’re a consumer looking for affordable, reliable domestic heating, make an informed choice by considering all the factors of your application and match those to the appropriate, properly tested and approved electric heater. And as always, exercise safety precautions and conservation by not exceeding the necessary heat level, and by turning the heater off promptly when done. Also, look into solar or wind powered electricity for your heaters.