How Blasch checks flow, heat and stress in the design, and tests the ceramic for thermal shock, abrasion, creep and corrosion.
A ceramic part that fails in the furnace is an expensive test.
So the testing happens before it is cast.
Refractory testing at Blasch checks the ceramic itself: thermal shock, abrasion to ASTM C704, acid resistance, creep, cup brick corrosion, strength, flame resistance and particle size, in the company's own lab. Modeling checks the design: CFD for gas flow, mixing and heat transfer, and FEA for stress and strain under the temperature profile the part will see. Together they answer two questions before a mold is made: will this material survive the duty, and will this shape do what the process needs?
Many Blasch parts exist to change a flow: tunnels that draw flue gas evenly, checkerwalls that mix gas, ferrules that guide it into boiler tubes.
In a published CFD comparison for a Claus reaction furnace, 22.5% of the flow did not reach the residence time needed for ammonia destruction above 1,250 °C with a choke ring. With a VectorWall mixing checkerwall, the whole flow from zone 1 did, and the pressure drop was about 900 Pa lower.
For StaBlox tunnels, the orifice size of every opening comes from a furnace model developed with BD Energy Systems.
Most ceramic parts in hot service do not fail from heat alone but from uneven heat, and that is something a model can see long before a crack can.
Finite element analysis shows where a shape will be stressed by its own weight, by the load above it and by temperature differences across it.
Thermal stress usually dominates. In a published FEA of a brick tunnel wall, the mortared wall reached stresses above the hot strength of the mortar, while the same wall built from individual dry set blocks stayed below 4.5 bar.
That is why Blasch designs large structures with expansion gaps and hollow sections, and why the shape is changed before the material is. Designing large and complex shapes
| Test | What it tells you |
|---|---|
| Thermal shock | How the ceramic survives fast heating and cooling |
| Abrasion, ASTM C704 | Volume lost under a standard particle blast |
| Acid testing | Resistance to acid gas and condensate |
| Creep resistance | Deformation under load at temperature |
| Cup brick corrosion | Attack by slag, melt or alkali |
| Strength | Modulus of rupture, cold and hot |
| Flame resistance | Behavior in direct flame |
| Particle analysis | Size distribution of raw materials |
Every production batch is also checked for strength, thermal shock behavior and dimensions.
Some tests are about geometry. In a laboratory test with air at room temperature, a ferrule with sharp edged inlet and outlet caused more than 35% more total pressure drop than one with a tapered inlet and chamfered outlet. That is why Blasch hex head ferrules carry a profiled inlet.
For the mullite bonded high alumina used in StaBlox, published creep tests show 1.11% deflection at 1,649 °C, against 7.86% for super duty firebrick tested at only 1,427 °C.
Measuring how a refractory or ceramic material behaves under the conditions it will see: heat, thermal shock, abrasion, chemical attack and load at temperature. Standard methods such as ASTM C704 make results comparable.
Ask your Blasch engineer. Comparative tests of an existing part or material against a proposed grade are part of many projects.
Blasch models the flow and stress around its components. Where a licensor or EPC holds the process model, Blasch works with them and their data.
SolidWorks for design, with flow modeling and finite element analysis for flow, heat transfer and stress.
Send the part, the conditions and a photo of the failure. A Blasch engineer looks at the heat, the flow and the material.
