IMPORTANCE OF PERMANENT LINEAR VARIATION IN NOT SHAPED.

TEIDE REFRACTORY SOLUTIONS, S.L. and his customers know that, the firing of Unshaped Refractories is perfomed at first start up of the facilities until reaching the operating temperature.

In this first phase, the refractory (Concretes, Ramming Masses, Plastics Masses, etc.), undoubtedly suffer variations in its dimensions; these variations, that remain after cooling, depend on several FACTORS:

• Temperature reached in furnaces.
• Physical and Chemical origin of the refractory ingredients.
• Mixing Liquids (water, phosphates, silicates…).
• Compaction right and effective.
• Drying and Setting up correctly.

TEIDE REFRACTORY SOLUTIONS, S..L., develops in his laboratories, several tests (following the norm E.N. 1402-6), in order to determination of dimentions variations that refractory materials suffer at different temperatures.

This type of tests is done in Programmable Ovens suitable for:

• Temperatures until 1650 ºC
• Increasing and Permanence programs to several temperatures in the same cycle.

Test’s oven

Verification of the material’s contraction.

The obtained results are very important to:

• Design lhe dimensions of construction parts.
• Draw up and adequate dilatation and contraction joints.
• Compatibilize REVERSIBLE LINEAR EXPANSION with the PERMANENT one.
• Help engineers to design correctly refractory installations.

Following there are shown some results of Teide’s studies regarding the behaviour of refractory concretes.

• Permanent linear varation of refractory concretes measurements after drying and firts firing-cooling.

A) Hormigones Trixotrópicos

According to E.N. 1402-1:2003, classification temperature for all types concrete is the one to which the total linear variation, determined agreed on EN 1402-6 norm, it is less than 1,5% of the contraction.

B) Gunning Concretes PYROSHOT

According to norm EN 1402-1:2003, classification temperature for gunning refractories is the one to which the total linear variation, determined agreed on EN 1402-6 norm, it is less than 1,5% of the contraction.