6 TPH Sodium Chloride MVR Evaporator Crystallizer: How CONQINPHI Cut Energy Costs by 72% for a Chemical Plant

Chemical plants handling brine streams face a persistent dilemma: how to recover sodium chloride efficiently without the crippling steam bills associated with traditional multi-effect evaporation. For a chlor-alkali derivative facility in the Middle East, the decision to switch to MVR evaporator crystallizer technology proved transformative. The project centered on a sodium chloride MVR evaporator rated for 6 tons per hour of crystalline salt production—a capacity point where mechanical vapor recompression delivers its strongest economic advantage over thermal alternatives.

The client’s existing four-effect forced-circulation system consumed 2.8 tons of live steam per ton of evaporated water. At current natural gas prices, that translated to over $340,000 in annual fuel costs alone. Maintenance was another headache: the thermal compressor required quarterly overhauls, and scaling in the final effect demanded monthly acid washes. Management issued a clear mandate: find a sodium chloride MVR evaporator crystallizer that would slash operating costs, reduce downtime, and fit within the existing building footprint. CONQINPHI’s proposal for a single-effect MVR evaporator crystallizer with integrated forced-circulation crystallization won the tender based on projected energy savings and compact layout.

System Design: Engineering Around NaCl Crystallization Behavior

H2: Thermal Process Configuration

Sodium chloride exhibits flat solubility curves with temperature, making it ideal for MVR evaporator crystallizer applications where operating temperature is driven by compressor discharge pressure rather than steam availability. CONQINPHI designed the system around these parameters:

• Evaporation rate: 6,000 kg/h water removal

• Crystallizer operating temperature: 78°C (optimized for NaCl supersaturation control and compressor efficiency)

• Compressor type: Single-stage centrifugal blower, 850 kW motor, titanium impeller

• Heat exchanger: Falling-film pre-concentrator + forced-circulation crystallizer body

The sodium chloride MVR evaporator uses the vapor generated in the crystallizer as its own heat source. After mechanical compression from 45 kPa to 105 kPa absolute, the superheated vapor enters the shell side of the main calandria. Condensate is flashed through multiple stages to preheat incoming feed, recovering every available kilojoule.

H2: Crystallizer and Solid-Liquid Separation

NaCl crystal growth demands precise control of magma density and circulation velocity. The sodium chloride evaporator crystallizer features a draft-tube baffle (DTB) design with an external circulation loop. Key specifications:

• Magma density: Maintained at 28–32% solids by volume through automated purge control

• Circulation rate: 4,200 m³/h via axial-flow pump, ensuring uniform temperature distribution and minimal wall scaling

• Crystal retention time: 4.5 hours, producing cubic NaCl crystals with mean size of 0.6–0.9 mm

Product slurry discharges continuously to a pusher centrifuge, then to a rotary dryer. Mother liquor returns to the crystallizer body, with a small bleed stream controlled by conductivity to prevent impurity buildup.

Commissioning Results: Performance Validation

H2: Energy and Throughput Metrics

After 90 days of continuous operation, third-party performance testing confirmed the sodium chloride MVR evaporator crystallizer exceeded design guarantees:

Compared to the previous four-effect thermal system, the sodium chloride MVR evaporator reduced equivalent energy costs by 72%. At local electricity rates of $0.07/kWh, annual operating savings exceeded $240,000—delivering full project payback in 26 months.

H2: Reliability and Maintenance

The centrifugal compressor has operated for 8,200 hours without major service. Vibration monitoring and oil analysis are performed monthly; no bearing wear trends have been detected. The MVR evaporator crystallizer heat exchanger requires cleaning every 60 days—double the interval of the old thermal system—thanks to lower operating temperatures and optimized circulation patterns.

CONQINPHI: Manufacturing Scale and Global Reach

H2: Dual-Base Production Capacity

CONQINPHI operates integrated manufacturing at Xinyang, Henan and Jiaozhou, Qingdao—two of China’s most capable centers for pressure equipment fabrication.

• Xinyang facility: 100,000 m² plant specializing in large-diameter vessels, titanium and duplex stainless cladding, and heavy structural skids. Houses CNC plasma cutting, automatic submerged arc welding, and full heat treatment ovens up to 12 meters in length.

• Jiaozhou facility: 80,000 m² precision workshop focused on compressor skids, crystallizer internals, automated valve stations, and electrical/control panel assembly.

This dual-base structure means a sodium chloride MVR evaporator crystallizer project can be fabricated in parallel streams:  Jiaozhou builds the pressure vessels and heat exchangers while Xinyang assembles the compressor package and control system. Typical delivery schedules are 30% shorter than single-facility competitors.

H2: OEM, ODM and Custom Engineering

CONQINPHI provides full OEM and ODM services for evaporation and crystallization equipment. Our process engineering group develops client-specific heat-and-mass balances, 3D piping layouts, and control narratives before fabrication begins.

H2: Export Experience Across Global Markets

With equipment operating in Southeast Asia, the Middle East, Africa, and Latin America, CONQINPHI understands the logistics of international sodium chloride evaporator crystallizer delivery. Our export team handles:

• Oversized vessel shipping and port coordination

• Customs clearance for pressure equipment

• On-site installation supervision and commissioning

• Remote technical support via secure VPN diagnostics

We do not serve the EU market, allowing us to focus engineering and service resources on the regions where our clients operate.

Request a Feasibility Study for Your Brine Recovery Project

If your facility processes sodium chloride solutions and rising steam costs are eroding margins, an MVR evaporator crystallizer may be the most impactful capital investment available. CONQINPHI offers no-obligation feasibility studies that include:

• Preliminary energy balance comparing MVR vs. thermal alternatives

• Estimated equipment footprint and utility requirements

• Budget-level pricing with performance guarantees

Submit your feed specifications—concentration, flow rate, impurity profile, and local utility costs. Our process engineers will deliver a technical proposal within 72 hours.