Thermal insulation and passivation.

The coal grinding plant including inlet and outlet pipes on top lose heat. Tata Steel Ijmuiden, requires an insulation material with high insulation value, scalable, easy to apply and with a very long service life.

Additionally, there is condensation accumulation within the filter housings situated atop the plant. This occurrence results from a thermal bridge extending from the exterior to the interior, combined with the presence of moisture within the filter housings. A comparable solution is being sought for this concern, mirroring the approach taken for the coal grinding mills themselves.

After several conversations, measurements and visits at installations, nC arrives at the following system structure for optimal installation insulation:

• Layer A: nC Corrosion Passivator – Primer Zinc C5
• Layer B: nC ProTherm – CUI-X
• Low C:nC Corrosion Passivator – Heavy Duty

Prior to the order, we completed a successful test on a number of process lines (here in standby), where the process lines regularly heat up to 125 degrees Celsius. The test showed good results. Here, nC ProTherm – CUI-X was applied with a dry film thickness of 5 mm.

• Thermal insulating coating λ W/(m-K) 0.022
• Prevents condensation, stops cold bridges
• Fire class B-S0-d0
• Breathable, does not form a damp screen
• Adheres chemically to the metal surface
• Does not contain solvents and metals
• Low consumption
• Paintable
• Life cycle up to 25 years

Detailed description of proposed solution

A detailed description on the proposed system construction for the coal mill and filter houses:

Layer A: nC Corrosion Passivator – Primer Zinc C5
For establishing a good and evenly adhesive primer, which at the same time provides all metal parts with long-term protection against corrosion: nC Corrosion Passivator – Primer Zinc C5, layer thickness layer A 70 mµ.

nC Corrosion Passivator – Primer Zinc C5 is a metal treatment fluid incorporated into a sprayable or roller/brushable carrier. Forms an active galvanic anti-corrosion layer in the metal. The metallic zinc powder acts as a sacrificial anode. Corrosive influences slowly change the layer into an impenetrable zinc oxide layer. This layer remains effective even if the paint is scratched. The combination of high purity binder and zinc ensures high mechanical resilience of the paint film while providing lasting active corrosion protection when the paint surface is damaged. This coating has been made suitable for overcoating with all nC ProTherm variants.

Layer B: nC ProTherm – CUI-X
To create a thermal insulating layer B on the entire mill (max. 150⁰C) which can withstand temperatures up to 150⁰C: nC ProTherm – CUI-X. Layer B is finished completely smooth. Layer thickness D 9mm on the hot parts of the mill, 13mm on the hot parts of the mill.

nC ProTherm – CUI-X is a sprayable thermal insulating coating for new or corroded metal surfaces up to 150⁰C. In addition, it prevents condensation in the interior. nC ProTherm – CUI-X adheres chemically to the metal surface via a sol-gel process. It is free of solvents. nC ProTherm – CUI-X can be applied in one layer in 3 mm to 12 mm WFT. Life cycle on function up to 25 years, depending on heat exposure.

Layer C (final coat): nC Corrosion Passivator – Heavy Duty
For finishing with an extremely abrasion and point load resistant coat that is easy to keep clean, even with water. Resistant to temperatures up to 120⁰C: nC Corrosion Passivator – Heavy Duty. Layer C is completely smooth. Layer C thickness is 300 microns over the entire mill, 13mm on the hot parts of the mill.

nC Corrosion Passivator – Heavy Duty (HD) is a combination of a corrosion passivating metal treatment fluid coated with an extremely tough carbon fiber epoxy technology that provides superior resistance to impact from falling rock, abrasive dry loading and external chemical influences. Transparent 2 component coating.