SME facilitators -Damon McCrory, Harbison-Walker Refractories Co & Barry Robinson, Middough
- One of the most important steps in a refractory installation
- Proper curing & dry-out are required for monolithics to achieve maximum properties for best reliability
- Monolithics have multiple dehydration points to get rid of free and chemically combined water
- High pressure builds during dry-out and increases with steam which can overcome material strength
- Dry-outs must be done in a controlled process following prescribed ramp rates and hold points to further allow proper development of designed properties
Best Practices
- Assure proper air cure times and temperatures (60*F to 90*F)
- Assure proper air exchange during Dry-out for circulation and venting of gasses and steam
- Use weep holes when possible
- The conservative approach is always the best approach
Example
- Discuss Dry-Out of Phos Bonded Plastic Burner Throats of Furnace. It was done electrically without proper air exchange.
Installation
- Select the appropriate material for the job. Consider installation technique and orientation of the equipment
- Ensure material is within shelf life
- Store materials properly
- Maintain temperatures between 60*F and 90*F
- Keep it DRY
Make sure proper equipment is used and it is in proper working order
When forming, make sure forms are water tight and sturdy enough to support the load of the material being installed
Assure proper accommodations for ambient temperatures. Remember that Monolithics have to go through a chemical reaction which is exothermic and that reaction is affected by ambient conditions.
Get refractory contractor involved in T/A planning early, up to 1 year in advance
Owner – Operators: make sure refractory installers have clean potable water sources for compressed air, welding machines, and plot space in unit for material storage, mixing equipment, gumming rigs, etc.
Having a refractory coordinator to interface with installer works best
Inspect linings as a team, and color code markups so refractory marks are distinguishable from mechanical.
Refractory installers prefer to be responsible for anchor installations as well as for material installations.
