If the system detects even trace amounts of hydrocarbons such as methane, the burner is immediately shut down to avoid the possibility of igniting the combustible vapor.
The combustible gas detection system for the Wacker Neuson HI 770XHD GD indirect-fired heater continuously samples the air surrounding the heater for the presence of hydrocarbons. If the system detects even trace amounts of hydrocarbons such as methane, the burner is immediately shut down to avoid the possibility of igniting the combustible vapor. This new option for the HI 770XHD GD heater increases operating safety when working in potentially volatile applications like oil and gas exploration, underground and above ground mining, and restoration.
The simple system consists of a gas sensor, gas detection system, engine air shutoff and strobe indicator. The ExP-rated gas detector continually monitors for and will pick up all types of hydrocarbons, including those resulting from nearby fuel spills, diesel vapors, etc.
Once hydrocarbons are detected, the two-stage shutdown system for the HI 770XHD GD heater advances safety by first reducing surface temperatures during shut down. When the level of hydrocarbons surrounding the heater reaches 10 percent of the lower explosive level (or LEL — the level at which sufficient concentration has been reached to cause an explosion if provided an ignition source) the detection system shuts off the burner. The blower continues to run to cool the heat exchanger until 20 percent LEL is reached, when a positive air shut down disables the generator to safely shut down the entire heater. If the hydrocarbon source does not reach 20 percent LEL, the burner restarts automatically once combustible gas levels drop below 10 percent LEL.
"Wacker Neuson realizes that safety is a top priority for our customers, especially those working in potentially volatile applications. We also understand each customer has unique needs, and this is why we offer both the HI770 with a gas detection system and our HIF Series Flameless heaters," said David Mencel, climate technology product manager of Wacker Neuson. "We worked with a third-party company to conduct a full review of the new gas detection system and perform live-fire tests with actual methane releases to ensure its reliability."
The third-party company confirmed that the gas sensor location has been optimized to detect hydrocarbon infiltration quickly, and that the heater shuts down safely. When an explosive mixture of methane was introduced to the test facility where the heater was operating, the heater shut down at prescribed detection levels with no detonation or ignition of the explosive gas.
The CSA-certified Wacker Neuson HI 770HXD GD indirect-fired heater is designed for continuous, 24/7 operation at extreme ambient temperatures reaching minus 60F (minus 51C). Featuring Recircul-Air technology to reduce fuel consumption and provide more uniform heating throughout the space, the HI 770XHD GD provides up to 770,000 BTU/hour (226 kW) heater input and 4,000 CFM airflow rating.