Overview
A pillow plate (also called a dimple or cavity heat-exchange plate) is made from two metal sheets—typically stainless steel—laser-welded and then inflated to create internal flow channels. When integrated into a crystallizer, these plates remove or add heat precisely to drive supersaturation and crystal growth with stable, controllable thermal gradients.
Notes: The page presents engineering principles and configuration options rather than any specific vendor’s proprietary data. Final duty, area, and hydraulics must be confirmed by project-specific design and testing.
Pillow Plate Section (Laser-Welded)
Laser-welded “pillow” channels increase turbulence and surface area, improving heat transfer while keeping construction compact and cleanable.
How It Works
Process Steps
- Feed prep: Filter and condition brine for target purity.
- Thermal control: Circulate heating/cooling media inside pillow plates to create controlled supersaturation (cooling or partial evaporation).
- Nucleation & growth: Maintain steady temperature and residence time to achieve desired crystal habit and size distribution.
- Solid–liquid separation: Separate crystals from mother liquor; wash and dry to specification.
Why Pillow Plates
- High heat-transfer area density
- Low fouling geometry with smooth channels
- Robust, fully welded construction
- Flexible shapes for tanks, walls, or immersion panels
Cooling Crystallizer — Industrial Example
Pillow plates can be used as jackets, immersion panels, or wall liners to drive controlled cooling in industrial crystallizers for salts and related products.
Applications
- Sea-salt and brine crystallization
- Industrial salt recovery and ZLD polishing
- Process brines (NaCl, mixed salts) with corrosion-resistant materials
- Pilot to full-scale continuous or batch crystallization
Engineering & Options
Materials typically include stainless steels (e.g., 304/316L) or higher-alloy/duplex grades for chloride-rich or harsh environments. Plate geometry (weld spacing, emboss height, flow path) is tailored to balance heat-transfer coefficient and pressure drop. Thermal duties, media selection (hot water, steam, thermal oil, chilled water), and clean-in-place strategies are engineered per feed chemistry and target crystal quality.
For detailed sizing (duty, area, ∆T, fouling allowance, hydraulics), we provide a project-specific design package after receiving feed assays, operating temperatures, utilities, and production targets.
Pillow Plate Jacketed Vessel
Jacketed tanks with pillow plates provide uniform heat flux for crystallizers and mother-liquor tanks, supporting stable growth and reproducible crystal size distribution.
Quality, Cleaning, and Operations
- Crystal quality: Controlled cooling/evaporation to tune habit and size; avoid occluded mother liquor.
- Cleanability: Smooth welded channels and removable/accessible panels support periodic cleaning against scaling.
- Automation: Temperature, residence time, and slurry density monitoring stabilize production and energy use.
