Municipal Waste to Energy

1) Municipal Waste to Energy (or Energy from Waste)

In modern Waste-to-Energy plants, the high plastic content of the trash combined with glass and scrap metals creates process conditions requiring special silicon carbide refractory materials. Our specially formulated SiC products can tolerate long exposure to fluctuating heat load, hot acids and oxidizing gases as well as abrasion in the grate area, while minimizing slag adherence.

Saint-Gobain Ceramic Materials provides full-furnace refractory capabilities that can help you to achieve the local environmental directives and your goals of cost effective energy production.

Tube blocks, grate line blocks and their related attachment systems are designed using state-of-the art CAD and Finite Element Modelling technologies to accomodate thermal expansion , steelwork movement and vibration.
Therefore, refractory shapes can be removed at any time for routine inspection and maintenance of the water tubes - which is difficult or impossible with monolithic linings.

According to the local heat load and oxidizing conditions we recommend either Carbofrax®M a silicate bonded SiC  or nitride bonded alternatives : Refrax®20 a silicon nitride bonded material or Cryston®CN790 and Refrax® 30, two oxynitride bonded SiC materials.

Our two major tile designs:

The so-called "45° Design" that is characterized by a blind hole at an angle of 45°. The blind holes fully protect the metallic anchors from corrosion and a thin wall thickness ensures a high heat transfer and thus avoids ash built-up. The system is usable only on vertical or sloped walls. The small gap between the tiles and the water wall is filled with a specially designed heat conductive SiC mortar. This design has been used successfully for more than 20 years.

T-Clip Design

The T-Clip design fully protects anchors and is usable regardless of the  the water wall slope, including ceilings. This tile design has been manufactured for more than 20 years. The T-Clip design can be used in 3 different configurations: with an air gap between tile and water wall; with a heat conductive  SiC mortar  filling the gap; with the tile back filled with our SG-SiC-60 SF or CC1225 self-flowing castable

Single boiler tubes protection :

Saint-Gobain Ceramic Materials has several years of experience in protecting single boiler tubes against erosion and corrosion in the superheater area, where the flue gas temperature is approximately 600 - 800°C. We developed ceramic tube shields designed for an easy and quick installation. The standard length is 250 mm and the available wall thickness is 8-10 mm. The material - Cryston® CN 550 CD - is a high thermal conductive and wear resistant nitride bonded SiC. A SiC based, high strength, air setting cement is used for the assembly

In less severe corrosion zones, the use of gunnable SiC monolithics with a SiC content ranging from 55 to 90%, applied on studded water wall panels may reduce initial costs. Where gunning is not applicable, trowelling mixes -SG SiC 80 T and SG SiC 90 T are available.
For the grate wall that is exposed to severe abrasion, we recommend SG SiC 80 G or GC904 gunnable monolithic.

2) Municipal waste gasification

Saint-Gobain has 50 years of experience in designing and manufacturing refractory linings for gasifiers.The growing interest in the use of gasification as an integral part of the disposal of municipal waste streams is served by our expertise in chromium oxide bearing specialty refractory shapes and monolithics. Gasification units are lined with high purity alumina bricks (AL 100, Alundum® AH199B) or chromium oxide based bricks (Zirchrom®60). For the vitrification units, we recommend Zirchrom® 60 shapes and our alumina-chrome low cement castable Chromcor®.