Engineering reference scenario — not a project record. This page describes a typical application class and the expected outcome range from correctly specified refractory. It is not a record of a specific SAPL project delivery. Real customer case studies will be published separately as signed permissions are obtained. Contact our engineering team for project-specific specifications.

Glass · Reference Scenario · 5 min read

Glass Tank Sidewall Life: How AZS-36 Plus Tuned Cooling Air Extends Flux-Line by 30–40%

Application class: 350 TPD container glass tank, mid-size Indian plant

Recommended brand class: Calderys India

Expected outcome ranges (illustrative — not project results)

Campaign Life Before

4 years

Campaign Life After

5.5 years (projected)

Improvement Pct

+38%

Annual Saving

~₹7–9 crore NPV (USD 740–950k)

Payback

Capex deferral covers premium AZS upcharge

Typical Baseline

A typical 350 TPD container glass tank running flux line at 1485°C with ~14% Na₂O experiences sidewall erosion that forces re-line at 4 years rather than the design 6 years. Glass defects ("stones") from refractory exudation degrade container yield. Sodium attack is aggressive in this temperature/chemistry envelope, and standard AZS-32 typically does not deliver design life.

Diagnostic Pattern

  • Typical flux-line wear rate: 10–14 mm/year on AZS-32 (target: 6–8 mm/year)
  • Glass quality: typically 1.0–1.4 stones/100 kg attributable to refractory exudation
  • Baseline flux-line: AZS-32 (32% ZrO₂)
  • Atmosphere: oxidising with elevated SO₃ content from petcoke fuel switch

Recommended Specification

  • Flux-line course: AZS-36 (36% ZrO₂, 50% Al₂O₃, 14% SiO₂) — premium grade
  • Bottom paving: standard AZS-32 (cost-effective, low wear zone)
  • Throat: AZS-41 (highest premium, most aggressive zone)
  • Crown: silica refractory (no change)
  • Total fused cast: 145 tonnes for the flux-line and throat campaign

Installation Best-Practice

  1. Block dressing: each AZS-36 block hand-dressed for tight joint fit
  2. Joint material: AZS-36 mortar, joint width 1.5 mm maximum
  3. Cooling air ring: re-tuned to 22 m³/min on flux line (up from 18 m³/min)
  4. Heat-up: 50°C/day for first 8 days, 30°C/day to operating temperature
  5. Calderys + SAPL technical team on site for 3 weeks of heat-up

Expected Outcome Range

Illustrative — not project results. Actual outcomes vary with operating conditions and installation quality.

  • Expected flux-line life: 4 years → 5.5 years (~30–40% improvement typical)
  • Expected defect ("stone") reduction: 1.0–1.4/100 kg → 0.2–0.4/100 kg (~70–80% lower)
  • Expected container line yield improvement: +1.0 to +1.6 percentage points
  • Capex deferral value: ~₹50–60 crore (USD 5.3–6.4M) tank rebuild deferred 18 months
  • Energy: improved cooling-air efficiency typically saves 2–3% on tank fuel

Premium AZS-36 at the flux line — paired with re-tuned cooling air — typically delivers both longer life AND better glass quality in this application class. The two outcomes compound: less refractory exudation → fewer stones → higher yield → better margin.

Products Referenced in This Scenario

This page is an illustrative engineering reference scenario for a typical application class — not a record of a specific SAPL project delivery. Financial figures (₹ and USD) are typical industry ranges drawn from May 2026 market data and standard industry practice. USD equivalents calculated at ₹94.5 per USD (May 2026 rate). Your specific outcome will vary with operating conditions, fuel mix, alloy grade, market pricing and installation quality. Contact our engineering team for a project-specific specification and indicative pricing.

FACING A SIMILAR REFRACTORY PROBLEM?

Send us your furnace type, current campaign life, and failure mode. Our engineers will come back with a project-specific specification proposal and indicative pricing within 4 business hours.