DTB Evaporator — High-Efficiency Crystal-Controlled Evaporation & Crystallization System 

Product Overview 

The DTB (Draft Tube Baffle) Evaporator is a high-efficiency evaporation and crystallization system integrating evaporation, crystallization, and crystal classification. It is especially suitable for processes requiring precise control over crystal size distribution, scale prevention, and production of high-purity crystalline products. With a draft tube and baffle structure, it enables selective crystal circulation and fine crystal removal, significantly improving crystallization quality and system stability. It is widely used in chemical, pharmaceutical, and inorganic salt industries. 

Working Principl

The feed liquid is heated and evaporated in the heating chamber, generating supersaturation. A circulation pump delivers the slurry to the bottom of the draft tube, where it rises to the evaporation surface.By controlling the circulation rate, evaporation temperature, and removal of fine crystals, this system can produce high-purity crystals with uniform particle size distribution. 

Core Components 

Draft Tube & Baffle: Key internals. The draft tube directs flow; the baffle creates a classification zone for coarse and fine crystal separation. 

Heating Chamber: Typically shell-and-tube type, providing heat for evaporation using steam or thermal oil. 

Separation Chamber: Provides sufficient space for vapor-liquid separation, equipped with demisters to minimize entrainment losses. 

Circulation Pump: Low-shear axial flow pump ensuring uniform slurry circulation without crystal damage. 

Fine Crystal Elimination System: Removes excessive fine crystals via heating or dilution to control crystal size distribution. 

Discharge System: Continuously or intermittently discharges crystal slurry at set concentration for downstream separation and drying. 

Product Features 

Precise Crystal Control: The draft tube and baffle structure combined with fine crystal removal mechanism enables accurate control over crystal size distribution, producing uniform, high-purity crystals. 

Scale & Fouling Resistance: Optimized flow paths and low-shear circulation significantly reduce scaling risks in heating tubes, extending continuous operation periods. 

Wide Concentration Range: Suitable for low to medium concentration feeds, especially for easily crystallizing, scaling, or heat-sensitive materials. 

Flexible Operation: Supports continuous, semi-continuous, or batch modes, compatible with evaporation, cooling, or vacuum crystallization methods. 

Compact Integrated Design: Minimizes intermediate tanks and piping, facilitating automatic control and easy cleaning. 

Typical Technical Specifications 

Parameter	Specification Range / Description
Processing Capacity	1–30 t/h (customizable)
Evaporation Temperature	45–80 ℃ (vacuum adjustable)
Crystal Size Range	0.1–1.5 mm (controllable)
Solid Content Range	5%–40% (vol.)
Material of Construction	316L, 2205, Hastelloy, Titanium, etc.
Control Mode	PLC/DCS automatic control, optional online particle size      monitoring
Crystallization Mode	Evaporative / Vacuum flash crystallization