Crystallization Reactor

The Challenge

A specialty chemicals manufacturer in Europe needed a crystallization reactor for producing potassium salt crystals with specific particle size distribution. The process required precise cooling rate control — too fast and you get fine crystals that are hard to filter; too slow and yield suffers.

The customer's main pain point was inconsistent crystal size in their existing batch reactor. They needed better temperature control precision and a way to add seed crystals at the right moment.

Our Solution

We designed an 8,000L crystallization reactor with features optimized for crystal growth control:

Technical Specifications

Key Design Features

• ✓ Multi-zone jacket for uniform cooling — no hot spots
• ✓ Precision temperature control system (±0.5°C)
• ✓ Seed crystal addition port with sanitary connection
• ✓ Low-shear pitched blade impeller — suspends crystals without breaking them
• ✓ Supersaturation monitoring via density probe
• ✓ Crystal growth observation port with lighting
• ✓ Bottom discharge with knife gate valve

Why Crystallization Is Different

Crystallization reactors have unique requirements compared to standard reactors:

• ✓ Temperature precision: Crystal size distribution depends on cooling rate — ±1°C can mean the difference between marketable product and waste
• ✓ Gentle agitation: Too aggressive and you break crystals; too gentle and they settle and grow unevenly
• ✓ Seed crystal addition: Timing and quantity affect nucleation — need controlled addition system
• ✓ Supersaturation control: Need real-time monitoring to prevent unwanted nucleation

The Result

Crystal size distribution narrowed by 40%. Filter cycle time reduced by 30% (larger, uniform crystals). Yield improved from 85% to 92%. Batch-to-batch consistency much improved.