A broad range of materials used in various industrial processes, including tar, resins, grease and varnish, must be stored at specific temperatures in order to maintain their viscosity. Otherwise, these materials may harden and even turn solid when temperatures in their immediate environment fall outside of recommended storage temperature ranges.
Drum heaters ensure that these materials remain within recommended temperatures during storage. When using drum heaters, it's important to do additional reading and keep the following best practices in mind to reduce the likelihood of serious injury and/or heater failure.
Heating Plastic Drums
Plastic drums are often used alongside or as an alternative to traditional 55-gallon metal drums. Given the malleability of plastics at high temperatures, it's always important to keep an eye on the drums heater's thermostat settings. Maximum temperatures for plastic drums typically vary depending on the types of plastics used in their construction.
Most drum heaters, especially those specifically designed to work with plastic drums, utilize thermostats that are preprogrammed to shut off the drum heater if maximum safe temperatures are reached. This prevents the drum heater from overheating and potentially damaging the plastic drum.
If you're using drum heaters without a built-in thermostat or ones that does not have an automatic shut-off feature, then you must be careful to never allow temperatures to exceed the drum's stated maximum temperature.
Beware of Dusty Environments
In the right concentration and under certain conditions, materials such as flour, grain, wood and certain metals can easily prove combustible and dust form. For this reason, it's never recommended to use drum heaters in any environment where large amounts of dust is constantly prevalent. These environments include areas near grain silos and grain elevators, hay storage areas and areas where potentially explosive and flammable materials are being reduced or processed.
If you have drums whose contents need to be heated, you should remove these drums from dusty environments before using any drum heater.
Taking Care with Electrical Wiring
While many drum heaters come pre-wired with standard electrical plugs, some models must be directly wired into an available electrical source prior to being used. Not only is it advised for a trained electrician to handle the wiring process, but said wiring should follow the NFPA 70 National Electric Code standards for safe electrical design.
For drum heaters using standard electrical plugs, it's crucial that the grounded plug is not tampered with in any way. It's not uncommon for workers to remove the ground prong in order to make the plug fit an ungrounded socket. Not only is it bad practice, but it also raises the risk of electrocution and drum heater failure.
Regardless of how the drum heater is wired, steps must be taken to avoid moisture-related shock hazards. Drum heaters must not be operated under high-humidity conditions or in moisture-laden environments. Care must also be taken to avoid accidental spills on the drum heater and its associated electrical wiring.
Other Safety Basics to Consider
In addition to the above best practices, there are other safety measures that must be followed when using drum heaters:
- When using silicon or metal band-style drum heaters, always position the bands below the level of the material within the drum. This allows the material to remain warm without overheating the actual drum.
- To relieve pressure that could build up as the drum's contents warm up, leave the drum vent open while using the drum heater. Ventilation considerations should be made for materials that emit noxious fumes when heated.
- Most drum heaters are rated for indoor use only, so they should never be operated outdoors.
Following the above best practices for operating drum heaters will help prevent serious injuries from occurring.