WtE/ERF Refractory – with great strength comes’ great responsibility.

Even todays modern silicon carbide tiled WtE/ERF boilers will have areas of monolithic. These may be gunned, rammed, cast or hand applied ‘plastic’. In many cases sites use the same material as before, maybe even the same spec. from when the boiler was first built.

“Great Strength”

In the same way we manage our personnel and equipment, we should manage our refractory.

Improvements in mix dynamics, grain size & application technique have enabled monolithic materials to achieve greater physical properties, in some cases giving an additional 50% or even 100% strength over ‘traditional’ mixes used only 3-4 years ago.

These developments go underutilised unless engineers, manager and specifiers consider the merits and capabilities of these new materials compared to those traditional products currently installed.

For example, many sites use a traditional ≈70% silicon carbide gunning cement with data sheet figures for cold crushing strength = 40 MPa at 800°C.

Refrax® ProGun 80 has at least a 50% increase in strength in this same temperature region, giving 60 MPa. In these dynamic boilers, the advances in material characteristics can mean the difference between material staying in place, or needing replacement during your next outage.

“Great Responsibility”

Likewise installation, including water content for dry bagged materials, should be closely monitored.

Much work has been completed over the years optimizing refractory cements with formulations closely engineered to ensure optimum particle size distribution by use of specific additives and cement types. Material with excess water may give easy application, but can have undesired effects on the strength and durability of the finished product.

Indeed 5% too much water can lose as much as 15-20% of the strength expected from a given material. The advances in technology are there to be used. If WtE plants monitor and ensure the correct use of these advanced monolithic materials, the rewards in lifetime and reduced costs can be significant.

Installation technique also has relevance here. Installation can be a science in itself and have significant impact on the lining. While we cannot replicate laboratory conditions inside the boiler, we should acknowledge that these factors will influence the longevity of the lining and act appropriately. Review of the installation instructions and close supervision can & will have a dramatic effect.

Working in partnership with knowledgeable manufacturers like Saint-Gobain, gaining their support from product selection through application and beyond for the best materials in each area will ensure optimum results.

These long-term cost effective materials will prove beneficial not only in $/£ value, but also in unforeseen areas.

Material that lasts longer, replacing traditional products that have been used for many years, maybe 10% more p.tonne, but can give other benefits.

- It lasts longer - so needs less replacement year on year - actual tonnes used in say a 5 year period for the unit will be less.

- Lower disposal costs – less tonnes used overall means less waste lining to dispose of – saving money, more cost effective long term

- Also better ecologically - less used lining to dispose of - used refractory lining has to be disposed of, lets minimise what we throw away.

- Less tonnage and therefore less downtime = shorter outages and more burning time for the unit

At Saint-Gobain we have a full range of monolithic materials engineered for the WtE/ERF market. Let us talk to you about what we can offer.

The Saint-Gobain Industrial Ceramics manufacturing plant & offices in the UK are based in Rainford, St. Helens. To find out more about Saint-Gobain refractory systems visit www.refractories.saint-gobain.com

T: 0044 7753 969493    E: keith.mann@saint-gobain.com