A recorded DigitalRefining webinar on a CFD study of a top-fired reformer running with one tunnel missing.
Many reformers keep running after a tunnel collapses.
This webinar puts a number on what that costs.
The webinar, recorded with DigitalRefining, presents Blasch modeling of a top-fired steam methane reformer that keeps running after one flue gas tunnel has collapsed and been cleared. In the published CFD study behind it, hydrogen in the process gas dropped by up to 9.7% next to the missing tunnel and by 0.95% across the furnace, which for a 2,000 t/d ammonia plant limited by its reformer means a theoretical loss of about 19 t/d.
The webinar explains why tunnels matter for flue gas flow and what happens when a single tunnel is removed while the others stay. It walks through the flow field, temperature profiles, residence time distribution, areas of recirculation and the effect on conversion in the catalyst tubes.
| Item | Value |
|---|---|
| Furnace | theoretical, 13 x 16 x 16 m |
| Tunnels | 8, each 16 m long and 1.8 m high, 66 cm inside width |
| Burners and tubes | 96 burners, 336 catalyst tubes |
| Case | all 8 tunnels against 7, with the outer tunnel removed |
The authors state the limits themselves: the reaction inside the tubes was not modeled, temperatures are comparative, and the cost figure rests on several assumptions.
A collapsed tunnel looks like a repair that can wait for the next turnaround, but the furnace pays for it every day in hydrogen it no longer makes.
If your reformer runs with a damaged or missing tunnel, the webinar gives you a way to weigh the repair against the lost production. Use your own capacity, the share of tubes near the damaged tunnel and your product price, and treat the published numbers as a model, not a measurement.
One collapsed tunnel can be rebuilt on its own with stocked parts, as described for StaBlox tunnel replacement. The study is summarized as a document on the page for the collapsed tunnel white paper, and the background on reformers is on the hydrogen and ammonia page.
No. It comes from a CFD model of a theoretical furnace. The authors present it as a comparison between eight and seven tunnels.
Flue gas no longer leaves evenly. Temperatures fall near the gap, part of the gas recirculates and the tubes in that area get less heat.
Yes. A single StaBlox tunnel can be built between existing brick tunnels with blocks, lids and bases from stock.
Send the tunnel dimensions and the furnace layout. A Blasch engineer checks what a single tunnel replacement needs.
