WHB Hopper Brick Damage

Waste Heat Boiler · Hopper

Problem Details

Background

The ash hopper of a waste-heat boiler collects ash settling from flue gas. Its brick lining long-term bears dust-laden gas scouring, ash abrasion and temperature changes, plus mechanical action from cleaning operations. Lining damage is a common WHB issue.

Failure Mechanism

Dust-laden gas scouring: gas turns and slows in the hopper zone; ash particles abrade the lining. Ash accumulation abrasion: accumulated ash moves and abrades the lining. Temperature changes: boiler start/stop and load swings cause temperature changes, shocking the lining. Mechanical action: cleaning (rapping, blowing) impacts the lining.

Consequences

After damage, hopper walls thin and overheat with ash-leak risk; fallen bricks may plug discharge equipment or damage devices, forcing shutdown for repair.

Solution

Material Selection and Parameters

Select the hopper for "high wear resistance + temperature-change resistance":

Material system: high-alumina brick (Al₂O₃≥55%) or low-porosity fireclay brick (Al₂O₃≥45%, porosity ≤15%). High-alumina resists wear; low-porosity fireclay is dense and penetration-resistant at good value for medium-low temperature hoppers;
Structural design: size hopper lining thickness by abrasion allowance; optimize wall angle for ash flow;
Joint materials: lay with matching mortar and tight joints.

Installation Essentials

Masonry control: lay with staggered joints, full mortar and joints ≤2mm. Anchoring: anchor the brick lining to the hopper wall reliably. Bake-out: follow the curve to avoid residual moisture in mortar.

Maintenance

Deslag promptly to reduce ash abrasion on the lining; inspect hopper bricks regularly and patch damage promptly. At maintenance, measure residual thickness and replace thinned zones; record abrasion data to optimize grade and structure.

Recommended Products

Featured

High-Alumina Brick LZ-55

High-alumina brick LZ-55 (Al₂O₃≥55%) with refractoriness ≥1770℃ offers dense structure, wear resistance against gas scouring and combined cold/hot strength—one of the most widely used shaped refractories.

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Low-Porosity Fireclay Brick

Low-porosity fireclay brick with Al₂O₃≥45%, apparent porosity ≤15% and RUL ≥1400℃. High density resists penetration by glass melt and furnace gases.