How the three StaBlox tunnel tiers differ in material, lids and side ports, and which reformer each one suits.
One block geometry, three material and lid combinations.
Chosen by how hard your reformer runs.
StaBlox flue gas tunnels share one mortar-free, interlocking geometry, but come in three tiers that differ in material, lid construction and side port design. Standard uses fireclay with extruded lids for stable, base-load reformers. Advanced moves to high alumina and cast interlocking lids for higher capacity or frequent cycling, and Premium uses mullite bonded high alumina with ports sized from a flow model where even tube temperatures are the main goal.
| Standard | Advanced | Premium | |
|---|---|---|---|
| Material | Fireclay | High alumina | Mullite bonded high alumina |
| Tunnel lids | Extruded | Cast interlocking | Cast interlocking |
| Side ports | Open or closed | Adjustable | Sized from a CFD model, 50 and more opening sizes |
| Typical unit | Stable base-load operation | Higher capacity, frequent thermal cycling | High flue gas velocity, tube temperature uniformity as the main target |
All three use interlocking side blocks, engineered expansion gaps and no mortar.
The Standard tier is for reformers that run steadily and need their brick tunnels replaced with a faster mortar-free system. Its fireclay has good thermal shock resistance. The lids are extruded under high pressure, which gives a dense part with a consistent grain along its length, suited to standard spans where thermal growth is the main load.
The Advanced tier changes to a dense alumina body with a higher modulus of rupture and better creep resistance. It suits units with higher bridge wall temperatures or frequent thermal cycles, where lid stability and adjustable ports matter.
In most reformer tunnels the first part to fail is the lid, so the choice between tiers is largely a choice of how the lid is made.
Extrusion makes a uniform slab, which works where the span is standard and the lid mainly has to follow thermal growth.
Casting allows a shape extrusion cannot make: a tongue and groove fit that locks the lid on all four sides. That keeps lids and blocks from walking during the vibration of a reformer startup, and it holds its tolerances even with the many port sizes of the Premium tier.
Lids deserve this attention. A published finite element analysis of a reformer tunnel lid shows that a temperature difference of 10 °F between its faces creates far more stress than its own weight. Why reformer tunnels fail covers that analysis.
The Premium tier combines mullite bonded high alumina with ports sized for each position from a flow model. In published data, mullite bonded alumina deflects 1.11% under creep load at 1,649 °C, where super duty brick deflects 7.86% at 1,427 °C, and it reaches a hot modulus of rupture of 1,700 psi against less than 600 psi for super duty brick.
Here the tunnel moves from structure to process: when every port draws its share, the hottest tubes come closer to the average and the furnace can run nearer its design temperature with less methane slip. In one ammonia reformer, the spread between coolest and hottest tube fell from 222 °F to 116 °F after the tunnels were replaced, as reported in a new kind of tunnel vision.
Start from the way your unit fails and runs, not from the price list. Steady operation with brick that simply wears out points to Standard. Lid failures and frequent trips point to Advanced. A reformer limited by a few hot tubes points to Premium. A Blasch engineer can map your furnace data to a tier, and the StaBlox flue gas tunnel system page describes the parts in detail.
Yes. The geometry is the same in every tier, with interlocking blocks, engineered expansion gaps and no mortar.
In published tests it creeps far less than super duty brick at higher temperature and keeps about three times the hot strength, which protects the sized ports and the lids over a campaign.
Premium, because its ports are sized for each position from a flow model of the furnace.
A precast lid with a tongue and groove fit on all four sides, which holds it in place against vibration at startup.
Send your operating data and how your current tunnels fail. A Blasch engineer will recommend a tier and explain why.
