What are Refrex® heatshields?
Refrex® heatshields are high temperature flexible heatshields for surface protection of furnace internals (eg. process tubes, riser tubes, hangers and manifolds)
Refrex® heatshield fabrics come in two different temperature grades:-
Refrex 1400 fabric (maximum 1370 °C)
Refrex 1200 fabric (maximum 1200 °C)
Refrex® fabrics are woven with threads made with different rovings. The rovings are assembled on a specified number of Refrex® filaments with a fibre diameter of 10-12 micron.
Properties of Refrex® 1200 and 1400 filaments and textiles:
- Non oxidizing
- Non hygroscopic
- Chemically inert
- Low conductivity
- Good abrasion resistance
Key Advantages :
- Custom made (Designed to meet mostl customer requirements)
- Prevents ageing acceleration of tube skin surface and welds of furnace internals
- Decreases coke-forming in radiant coils and tubes
- Shields sections of process tubes susceptible to hotspots
- 60% reflection rate of radiant heat
- Shorter lead time
- Easy to install and engineered to last
- Easily removed and fully re-useable without damaging the heatshield
Moreover, the heatshields, tie-cords and sewing yarn are made out of 100% Refrex® material, which can withstand up to 1200 °C (for Refrex® 1200) and 1370 °C (for Refrex® 1400) flue gas temperatures.
All other materials used in the heatshields such as ceramic buttons and insulation materials are also able to withstand these high flue gas temperatures.
Condition of Refrex Heatshields Before and After 4 years of installation on a furnace U-bend and Y-joint
Condition of Refrax® heatshields on U-bend and Y-Joint before firing
Condition of Refrex® heatshields on U-bend and Y-Joint after 4years of firing
Refrex® heatshields application:
- Process Tubes
- Riser Tubes
Installation of Refrex heatshields using a 180° half tube shield design protecting tubes from direct radiant heat
Pre-fabricated Refrex heatshields for riser tubes
As can be seen in the pictures above the Refrex® heatshields are attached with tie-cords, sleevings and ceramic buttons / buttonholes.This makes the heatshields easier to install, removable and reusable.