To design a circulation heater that can heat up a varying mixtures of nitrogen and hydrogen gas at varying temperatures. With the varying mixture of gases the ability to transfer heat effectively changes.
While Nitrogen is a very stable gas, hydrogen is a highly combustible gas with an auto ignition point of 997°F and must be treated carefully. Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks.
Certain design features were key in making this heater safe. Heatrex designed for a low watt density to keep the element’s sheath temperature below the auto ignition point of the gases. The heater was also constructed with an extra high limit thermocouple (mounted on the heaters flange) in addition to the standard high limit thermocouple (mounted on the element’s sheath). Heatrex also built in an additional safety to the system by recommending a terminal box standoff, creating an air gap between the heaters flange and the terminal box with the customer’s line wires.
- Low watt density for low sheath temperature and longer heater life
- High Limit protection from low flow (sheath mounted thermocouple)
- High Limit protection from outside heat (flange mounted thermocouple)
- Extended terminal box to provide lower temperature to the terminal box allowing the customer to have smaller gauge line wires.