Many industrial operators face significant challenges when transferring liquid sulfur, particularly with equipment reliability. A common frustration is the rapid failure of gear pumps—often within just 30 hours of operation—due to sulfur solidification and pump corrosion. Let's explore why this happens and how BONVE's specialized rotary lobe pumps provide a superior solution.

The Problem: Why Gear Pumps Fail with Liquid Sulfur

Liquid sulfur presents unique handling challenges that expose critical limitations in standard gear pump designs:

1. Solidification Risks With a melting point of 115-120°C, liquid sulfur rapidly solidifies into hard lumps when cooled. Gear pumps' tiny operational clearances (0.05-0.2mm) get easily blocked by solidified sulfur, causing jamming or catastrophic damage during forced operation.

2. Corrosive & Abrasive Nature High-temperature liquid sulfur corrodes common steels, while impurities (unmelted sulfur, rust particles) act as abrasives—accelerating wear on gear surfaces and bearings.

3. Design Misalignment Gear pumps rely on precise clearances and media lubrication—both problematic for sulfur. Their seals often fail under high temperatures, allowing air ingress that further accelerates sulfur solidification.

4. Operational Vulnerabilities Inadequate insulation, improper shutdown procedures, or insufficient preheating exacerbate these issues, leading to premature failure.

BONVE's Engineered Solution: Rotary Lobe Pumps for Liquid Sulfur

Our rotary lobe pumps are specifically designed to address liquid sulfur's unique challenges, delivering extended service life through these critical features:

· Superior Material Construction Duplex 2205 stainless steel provides exceptional resistance to sulfur's corrosive effects and abrasive particles.

· High-Temperature Sealing FFKM O-rings withstand operating temperatures up to 200°C, maintaining integrity where standard rubber compounds fail.

· Reliable Shaft Sealing Single-face mechanical seal without flushing minimizes potential failure points while preventing sulfur leakage.

· Integral Temperature Control Heating jackets on both casing and cover maintain optimal sulfur temperature, preventing solidification.

· Operational Safeguards (End-user responsibility) Full preheating before restart ensures smooth operation and prevents damage from solidified sulfur.

Application Example

For a typical liquid sulfur transfer application (200°C, 10m³/Hr, 4 Bar), we recommend Rotary Lobe Pump model 80BV12-20 :

Why Choose BONVE for Liquid Sulfur Transfer?

Our rotary lobe pumps' robust design, larger operational clearances, and sulfur-specific materials overcome the limitations of gear pumps. By addressing the root causes of failure—solidification, corrosion, and design constraints—BONVE pumps deliver reliable performance for liquid sulfur applications.

Contact our technical team today to discuss your specific liquid sulfur transfer requirements and discover how BONVE's solutions can reduce downtime and maintenance costs.