BLOOR ENGINEERING -- Refractory Dry-Out Schedule
Bloor Engineering Ltd | Unit 10, Donk Hill Farm, Catton, Swadlincote, DE12 8LW | 01283 210987
Refractory Dry-Out Schedule Generator
Generate safe heat-up schedules for furnace builds, relines, and refractory repairs. Prevents spalling, cracking, and steam explosions from trapped moisture. All parameters are editable; the chart updates instantly.
1
Refractory Configuration
Thicker linings require longer holds and slower ramps
Minimum 1 day for castables; affects initial hold duration
Used to estimate total moisture content
2
Schedule Parameters
| Stage | From (°C) | To (°C) | Ramp (°C/hr) | Ramp Time | Hold (hrs) | Cumulative | Notes |
|---|
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Visual Schedule Chart
4
Printable Schedule
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5
Critical Temperatures Reference
| Temperature | Event | Risk if Rate Exceeded |
|---|---|---|
| 100 -- 120°C | Free water evaporation | Steam pressure builds inside lining, causing explosive spalling |
| 200 -- 350°C | Chemically bound water release | Cracking, delamination of lining layers |
| 573°C | Quartz inversion (α → β) | 0.45% volume change causes cracking in silica-containing refractories |
| 700 -- 900°C | Ceramic bond formation | Structural weakness if ramped too quickly through bonding range |
| 1000°C+ | Sintering begins | Shrinkage stress causes cracking at joints and anchors |
| Refractory Type | Max Ramp (first fire) | Max Ramp (subsequent) | Min Hold at 110°C |
|---|---|---|---|
| Dense castable | 25°C/hr | 50°C/hr | 24 hrs |
| Insulating castable | 15°C/hr | 30°C/hr | 24 hrs |
| Ceramic fibre | 50°C/hr | 100°C/hr | 4 hrs |
| Fire brick | 30°C/hr | 60°C/hr | 12 hrs |
| Rammed / gunned | 20°C/hr | 40°C/hr | 24 hrs |
| Plastic refractory | 15°C/hr | 30°C/hr | 24 hrs |
| Monolithic (vibration cast) | 20°C/hr | 40°C/hr | 24 hrs |
- Starting too fast -- Always slow through 100-120°C. Free water must escape as steam before the core temperature rises above boiling point.
- Insufficient hold at 110°C -- Moisture must fully escape from the core, not just the surface. Thicker linings (>150mm) need 24+ hour holds.
- Ignoring quartz inversion at 573°C -- Slow to 15°C/hr through the 550-600°C band. The α to β quartz phase change causes a 0.45% volume change.
- Skipping intermediate holds -- Thermal gradients between hot face and cold face cause differential expansion, leading to cracking and delamination.
- Poor ventilation -- Ensure furnace vents, dampers, or doors are open during moisture release stages (below 300°C). Trapped steam has nowhere to go.