Product Introduction

　 　Forced-circulation evaporator It is a highly efficient evaporation and crystallization device that uses external force to forcibly drive the circulation of the feed liquid. At its core, it employs “forced turbulence + in-tube evaporation” technology. A circulating pump ensures that the feed liquid flows through the heating tubes at a high velocity (2–5 m/s), thereby preventing fouling and crystal deposition on the tube walls and enabling stable, continuous evaporation. The equipment’s key advantages—strong anti-fouling performance, stable and reliable operation, and compatibility with challenging feedstocks—make it widely applicable in concentration and crystallization processes for high-salt, high-viscosity, easily crystallizing, and suspended-solid-containing solutions in industries such as chemical processing, metallurgy, environmental protection, and pharmaceuticals. It serves as a core piece of equipment for the evaporation and treatment of complex feedstocks and can be custom-designed according to users’ specific material characteristics, production capacity requirements, and process objectives.

Product Category

　　According to the circulation method, heating structure, and application scenarios, forced-circulation evaporators are mainly classified into the following categories:

　 　1. Classified by cyclic power

　 　▪ Pump-forced circulation evaporator: Powered by a centrifugal circulation pump, this system features a controllable liquid flow rate and is suitable for most industrial applications, making it the mainstream type.

　 　▪ Jet-induced forced-circulation evaporator: A steam ejector is used to generate negative pressure suction, driving the fluid circulation without the need for an additional circulating pump. This system is energy-efficient and well-suited for high-temperature and high-pressure applications.

　　2. Classified by heating structure

　 　▪ Vertical shell-and-tube forced-circulation evaporator: The heating chamber features a vertical shell-and-tube structure, which occupies a small footprint yet offers a large heat transfer area, making it suitable for large-scale continuous production.

　　 ▪ Horizontal shell-and-tube forced-circulation evaporator: The heating chamber is horizontally arranged, making inspection and maintenance convenient, and it is well-suited for handling materials containing large amounts of suspended solids that are prone to clogging.

　　 3. Combine and classify according to the process.

　 　▪ Single-effect forced-circulation evaporator: Simple structure and low investment cost, suitable for intermittent processing of small-scale, high-difficulty materials.

　 　▪ Multi-effect forced-circulation evaporator (2-4 effects): Energy savings are achieved through cascade utilization of steam, reducing energy consumption by 40% to 70% compared to single-effect equipment, making it suitable for large-scale, continuous production.

　 　▪ MVR forced-circulation evaporator: Combined with mechanical vapor recompression technology, energy consumption is reduced by 60% to 85% compared to conventional multi-effect equipment, offering significant environmental and energy-saving benefits. It is particularly well-suited for applications with high energy consumption and stringent environmental requirements.

Performance Features

　　 1. Strong anti-scaling capability: The feed liquid flows in turbulent mode at a high velocity (2–5 m/s), significantly reducing the residence time of the material on the pipe walls and effectively inhibiting scaling and crystal deposition. The system can handle solutions containing suspended solids (up to 5%), easily crystallizing substances (such as sodium sulfate and ammonium chloride), and solutions with high hardness (high calcium and magnesium ion content). The equipment boasts a long operational lifespan—continuous operation for 3–6 months without the need for disassembly or cleaning.

　 　2. Stable and reliable operation: The forced-circulation design ensures uniform flow of the material liquid and stable heat transfer, preventing dry-wall formation and localized overheating. Even when processing high-viscosity materials (up to 1000 mPa·s) and high-concentration materials (20%–60%), continuous and stable operation can be maintained.

　 　3. High heat transfer efficiency: In turbulent flow conditions, the boundary layer thickness of the feed liquid is thin, and the heat transfer coefficient is high (1500–4500 W/(m²·℃)). The evaporation intensity is superior to that of conventional natural-circulation evaporators, and the evaporation capacity of a single unit can range from 1 ton/hour to over 200 tons/hour.

　 　4. Extremely wide compatibility: Capable of handling various complex materials, including high-salinity wastewater (with salinity ranging from 5% to 25%), high-viscosity materials, materials containing particulate suspensions, and corrosive materials (by selecting corrosion-resistant materials such as titanium and Hastelloy).

　 　5. Flexible operation: It can operate under both atmospheric and reduced-pressure (vacuum) conditions, with a wide operating temperature range (40–150℃). By adjusting the flow rate of the circulation pump and the temperature of the heating medium, the evaporation rate can be precisely controlled.

　 　6. Easy maintenance: The heating tube features a straight-tube design that is resistant to clogging. The equipment boasts a modular structure, allowing for quick disassembly and replacement of components during maintenance, thereby reducing maintenance costs.

Application scenarios

　　Thanks to their core advantages of strong anti-scaling capability and high stability, forced-circulation evaporators are widely used in the following industries:

　　 1. Chemical industry: Crystallization of salt chemicals (sodium chloride, sodium sulfate, potassium chloride); concentration of chemical wastewater (dye wastewater, pesticide intermediate wastewater); concentration of organic salt solutions (sodium acetate, calcium formate).

　 　2. Metallurgical Industry: Concentration of rare earth element extraction solutions, treatment of wastewater from non-ferrous metal smelting (including wastewater containing heavy metals such as copper, nickel, and zinc), and recovery of electroplating solutions (concentrating and reusing spent chromium-plating and zinc-plating solutions).

　　 3. Environmental Protection Industry: High High-salt COD wastewater treatment (comprehensive wastewater from chemical industrial parks, coal-to-chemical wastewater); concentration of leachate from landfills (subsequent concentration and volume reduction after DTRO/DCMD); zero-discharge treatment of desulfurization wastewater.

　 　4. Pharmaceutical Industry: Antibiotic crystallization (penicillin, cephalosporins), concentration of traditional Chinese medicine extracts (concentrated extracts containing large amounts of suspended solids), and concentration of pharmaceutical intermediates (high-viscosity materials that are prone to decomposition);

　 　5. Other fields: Food additive production (citric acid, lactic acid crystallization), lithium battery material production (concentration of lithium salt solutions, treatment of cathode material waste liquids), and black liquor concentration in the paper industry (high-viscosity waste liquid containing lignin and suspended solids).