Product Introduction

　 　Falling film evaporator It is a highly efficient and energy-saving evaporation-crystallization device that employs “thin-film evaporation” technology. In this process, the feed liquid is evenly distributed along the inner wall of the heating tubes to form a thin-film flow, enabling rapid heat transfer and evaporation through the shell-side heating medium (such as steam or thermal oil). The device’s core advantages—low energy consumption, high evaporation intensity, and gentle treatment of materials—make it widely applicable in solution concentration, crystal separation, and wastewater treatment scenarios across industries including chemical, food, pharmaceutical, and environmental protection. It is a key piece of equipment in evaporation-crystallization processes and can be custom-designed according to users’ production capacity, material characteristics, and specific process requirements.

Product Category

　　According to their structural form, material flow direction, and application scenarios, falling-film evaporators are mainly categorized as follows:

　　 1. Classified by structural form

　　 ▪ Vertical falling-film evaporator: The main component is a vertical heating tube bundle. The feed liquid flows downward along the inner wall of the tubes, forming a film. This design features a small footprint and high evaporation efficiency, making it suitable for large-scale continuous production.

　　 ▪ Horizontal falling-film evaporator: Adopting a horizontal layout, it is suitable for high-viscosity and easily crystallizing materials. It offers convenient inspection and maintenance, making it ideal for small to medium production capacities and intermittent production processes.

　 　2. Classified by heating medium

　　 ▪ Steam-heated falling-film evaporator: Using saturated steam as the heat source, with a high heat transfer coefficient and low operating costs, it is the mainstream choice in the industrial sector.

　 　▪ Heat-transfer oil-heated falling-film evaporator: Suitable for high-temperature evaporation applications (with heating temperatures reaching over 300℃), ideal for materials that are low in thermal sensitivity and require high-temperature concentration.

　 　3. Combine and classify according to the process.

　 　▪ Single-effect falling-film evaporator: Simple structure and low investment cost, suitable for small-scale concentration and processing of low-boiling-point materials.

　 　▪ Multi-effect falling-film evaporator (2-5 effects): Energy savings are achieved through the secondary utilization of steam, with energy consumption reduced to only 1/2 to 1/5 of that of single-effect equipment, making it suitable for large-scale, continuous production.

　　 ▪ MVR Falling Film Evaporator: Combined with mechanical vapor recompression technology, energy consumption is reduced by 60% to 80% compared to conventional multi-effect equipment, offering significant environmental and energy-saving benefits and making it well-suited for scenarios with high energy demands.

Performance Features

　 　1. High efficiency and energy saving: The liquid film is thin (typically 0.1–1.0 mm), with a high heat transfer coefficient (2,000–6,000 W/(m²·℃)), and its evaporation intensity is 2–5 times that of conventional immersion evaporators. The multi-effect/MVR combination significantly reduces energy consumption; MVR systems are more than 80% more energy-efficient than single-effect units.

　 　2. Gentle handling: The feed liquid stays in the equipment for a short period (only a few to dozens of seconds) and is heated uniformly, effectively preventing the decomposition and deterioration of heat-sensitive materials (such as food and pharmaceutical intermediates).

　 　3. Stable operation: The liquid applicator is precisely designed to ensure an even liquid film covers the tube wall, thereby preventing dry-wall phenomena. The equipment can operate under vacuum conditions (operating temperature: 40–80℃), further protecting heat-sensitive materials while reducing energy consumption.

　 　4. Wide compatibility: It can handle various solutions with concentrations ranging from 5% to 40%. It is compatible with materials having low viscosity (<50 mPa·s) to medium-to-high viscosity (<500 mPa·s). By customizing the liquid distribution device and material selection, it can be adapted to corrosive media (such as acidic or alkaline solutions), materials prone to crystallization, and those containing small amounts of suspended solids.

　 　5. Compact structure: The vertical structure occupies a small footprint, and the evaporation capacity of a single unit can range from 0.5 t/h to over 100 t/h. Its modular design facilitates easy expansion and subsequent maintenance.

　 　6. Environmental compliance: Closed-loop operation reduces solvent volatilization and pollution, while the condensation and recovery of secondary steam enable the recycling of water resources and solvents, thereby meeting environmental emission requirements.

Application scenarios

　　Thanks to its core advantages of high efficiency and gentle operation, falling-film evaporators are widely used in the following industries:

　　 1. Chemical industry: Concentration of salt solutions (such as sodium chloride, potassium chloride); recovery of organic solvents (such as ethanol, methanol, acetone); concentration of chemical intermediates (such as dye and coating intermediates).

　 　2. Food industry: Fruit juice concentrates (orange juice, apple juice), dairy product concentrates (milk, yogurt), sucrose/maltose syrup concentrates, and plant extract concentrates (tea polyphenols, flavonoids);

　 　3. Pharmaceutical Industry: Concentration of Chinese medicinal extracts, concentration of antibiotic solutions, concentration and purification of vitamins, and treatment of pharmaceutical wastewater;

　 　4. Environmental Protection Industry: Treatment of high-salinity wastewater (chemical industry wastewater, electroplating wastewater, dyeing and printing wastewater); concentration and volume reduction of organic wastewater (to lower subsequent treatment costs).

　 　5. Other fields: Desalination of seawater, concentration of black liquor from papermaking, recovery of electroplating solutions, and production of lithium battery materials (concentration of lithium salt solutions).