Crystallizer
Evaporation
1. Product Overview
Crystallizers create controlled supersaturation so that dissolved solutes precipitate as crystals. Common types include DTB (draft tube baffle), vacuum, and cooling crystallizers, widely used in the chemical, food, pharmaceutical, and environmental sectors for high-purity crystal production.
2. Working Principle
Inside the crystallizer, supersaturation is reached through evaporation, cooling, or vacuum flash evaporation. Nucleation occurs and crystals grow under controlled conditions, kept in suspension by agitation or circulation. Once the target size is reached, crystals are discharged from the bottom while mother liquor is recycled or purged.
3. System Classification
Table
| Type | Features | Application |
|---|---|---|
| DTB crystallizer | Internal draft tube and baffle, high circulation efficiency | Continuous operation, large capacity, strict size control |
| Vacuum crystallizer | Reduced-pressure evaporation, low temperature | Heat-sensitive materials, e.g., sugar, certain salts |
| Cooling crystallizer | Heat removal via jacket or internal coils | Systems with strong temperature-dependent solubility |
| Evaporative crystallizer | Solvent evaporation creates supersaturation | Systems with weak temperature-dependent solubility |
4. Detailed Technical Parameters
4.1 Common Materials
Table
| Material | Application | Remarks |
|---|---|---|
| SS304 / SS316L | Product-contact parts | Food, pharma, general chemical |
| Carbon steel | Shell, supports | Non-contact, rubber-lined or coated |
| Hastelloy / Titanium | Highly corrosive mother liquor | Strong acids, high chloride |
4.2 Typical Specifications (DTB crystallizer, subject to design)
Table
| Parameter | Range |
|---|---|
| Throughput | 30,000 ~ 60,000 L/h (scalable) |
| Tank diameter | 1 ~ 5 m |
| Tank height | 3 ~ 10 m |
| Operating temperature | 0 ~ 50 °C (extendable) |
| Target crystal size | 0.3 ~ 0.8 mm (adjustable) |
| Residence time | 30 ~ 90 minutes |
4.3 Design Conditions & Performance
Table
| Parameter | Specification |
|---|---|
| Product purity | > 99% (process-dependent) |
| Crystal uniformity | Controllable particle size distribution |
| Agitator speed | 10 ~ 60 rpm (DTB type, size-dependent) |
| Circulation flow | Matched to tank volume to ensure suspension |
5. Electrical Parameters
(same as the MVR evaporator table)
6. Key Component Selection
Table
| Component | Common Brand / Material | Features |
|---|---|---|
| Crystallizer vessel | SS304 / SS316L / CS lined | With jacket or internal coils, insulation |
| Draft tube (DTB) | SS304 / SS316L | Controls internal circulation, eliminates dead zones |
| Baffle | Same as vessel | Stabilizes flow, prevents short-circuiting |
| Agitator / circulation pump | Custom | Low-speed, high-flow, crystal-friendly |
| Discharge valve | Pneumatic or electric | For crystal slurry, anti-plugging |
7. Typical Applications
Chemical: Sodium sulfate, ammonium chloride, citric acid, benzoic acid crystallization
Food: Sucrose, salt, glucose crystallization
Pharmaceutical: API crystallization, vitamin purification
Environmental: ZLD salt recovery, struvite recovery
New energy: Battery material precursor crystallization
8. Design Standards & Certifications
Table
| Standard | Description |
|---|---|
| ASME Section VIII Div.1 | Pressure vessel design and fabrication |
| PED 2014/68/EU | EU Pressure Equipment Directive |
| ATEX 2014/34/EU | Explosion protection directive (if applicable) |
| GMP / FDA | Pharmaceutical and food-grade requirements |
| DGRL 2014/68/EU | EU Pressure Equipment Directive (common in German-speaking regions) |
| ISO 9001:2015 | Quality management system |
9. Optional Custom Configurations
Table
| Option | Details |
|---|---|
| Operation mode | Continuous (MSMPR/DTB) / Batch |
| Temperature control | Jacket, internal coils, external heat exchanger |
| Seeding system | Precise control of seed quantity and size |
| Automatic control | PLC/DCS with online particle size, density, level monitoring |
| CIP/SIP | Clean-in-place / steam-in-place |
10. Warranty Terms
(same as the MVR evaporator)
11. Packaging and Delivery
Table
| Item | Packaging |
|---|---|
| Crystallizer vessel | Tarpaulin wrap, naked or wooden skid |
| Agitator / circulation pump | Wooden cases, shaft rust-proofing |
| Electrical / instruments / valves | Waterproof sealed packaging in wooden cases |
| Container estimate | Diameter ≤2 m: approx. 1~2×40'HC; larger by break bulk |
12. Information Required for Inquiry
12. Information Required for Quotation: material name and solubility curve, target crystal size and distribution, throughput (kg/h or t/d), feed concentration and temperature, target purity, heat sensitivity, preferred crystallization mode (cooling/evaporation/vacuum), material requirements, power supply, delivery terms, and destination port.