How to Select Proper Refractories for Regenerator of Glass Furnaces

• Published on April 24, 2019

Michael Mann

Michael Mann

Key Account Manager & Shareholder

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Regenerator Checker Packs

Fuel-fired furnaces in the glass industry typically utilize checker blocks to improve efficiency by taking advantage of the excellent heat exchange properties inherent in ceramic materials.

As the furnace exhausts through the check pack,the blocks are preheated by the waste gases,providing a source of energy to preheat the combustion air when the cycle is reversed.

Regenerator efficiency can be affected by a variety of factors, from pack design to regenerator size.The refractory materials utilized in regenerators must be able to withstand many different forms of attack, including corrosion by alkalis, silica and sulfates,as well as thermal shock and creep,

The selection of refractory materials is critical to the operation and life cycle of the regenerator.

Top Checkers:

This zone has an atmosphere laden with alkali vapors and solid batch carryover(CaO,SiO2).High temperature cycling and oxidizing/reducing effects are also considered.

• AZS Checker blocks
• Magnesia Checker blocks 98%
• Magnesia Zircon blocks
• Corundum Checker blocks

Middle Checkers:

This zone has temperature fluctuations that are considered relatively mild.Solid carryover is low and less reactive due to low temperature.The atmosphere is rich in alkali vapors and some deposition can occur.

• Magnesia Checker blocks 95%
• Magnesia Chrome Blocks

Condensate Zone

This zone had low temperatures but ranges may be wide where cold incoming air enters the checker setting. A large amount of condensation of volatile constituents is present from the exhaust gas.Plugging may occur from the entrapment of solid dust and fragments from higher up in the setting.Reducing conditions can also affect refractory selection.

• Magnesia Checker blocks 96%
• Magnesia Chrome blocks(Direct bonded)
• Magnesia Zircon blocks

Lower Checkers,Rider Tile and Secondaries

This zone had temperature cycling and sulphate condensate that can be an issue.In addition,creep resistance is critical in this application due to the increased load on the refractory.

• Low porosity Fireclay Checker blocks
• Magnesia Checker blocks 92%
• Magnesia Checker blocks 95% 
• Sillimanite brick 

Regerator Crown/Upper Wall and Upper Division Walls

This section of the regenerator must resist solid carryover attack and is typically subjected to higher temperatures.Careful consideration of insulation being used on crowns must be taken regarding hot-face temperature and expected mean temperature of the hot face refractory.

• Magnesia Bricks 95/97/98or silica brick 96A(Crown
• Alumina brick
• Magnesia Chrome brick(Direct Bonded)
• Sillimanite brick
• Mullite brick
• Magnesia Brick 

Target Walls 

Target walls experience extreme conditions from batch carryover.Issues are most severe in end-port furnaces and the first two or three ports in side-port furnaces.

• Fused Mullite brick
• Sintered AZS block
• Sillimanite brick
• Mullite brick
• Magnesia Zircon brick
• Magnesia brick 96

Middle Walls 

This part of the regenerator is exposed to lower temperatures with relatively minor thermal cycling.The most important requirement for the refectory selection is good resistance to creep.

• Magnesia brick 96
• Sillimanite brick
• Mullite brick

Lower Walls 

Like the lower checkers, this section is exposed to temperature cycling and sulphate condensate that can be an issue.In addition,creep resistance is critical in this application due to increased load on the refractory.

• Sillimanite brick
• Fireclay brick

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