Working principle
Steam cycle utilization: Multiple evaporators are connected in series, with the secondary steam generated by the previous
evaporator serving as the heat source for the subsequent evaporator. Only supply steam to the first evaporator, and subsequent effects rely on the secondary steam generated by the previous effect for heating and evaporation, thereby achieving multiple cycles of steam utilization and saving heating steam.
Boiling point pressure relationship: Based on the principle that water has different boiling points at different pressures, in a multi effect evaporator, the pressure of each evaporator decreases sequentially, causing the solution to boil and evaporate at different pressures, thereby achieving waste heat reuse.
System Composition
Evaporator: It is the core component of a multi effect evaporator, usually consisting of a heating chamber and an evaporation chamber, used for heating and evaporating materials.
Separators: Used to separate the vapor-liquid mixture generated during the evaporation process, obtaining concentrated materials and secondary steam.
Circulating pump: used to force the material to circulate in the evaporator, improve heat transfer efficiency, enable the material to be uniformly heated, and also help handle high viscosity materials.
Condenser: located at the end of the system, used to condense the secondary steam generated by the final effect evaporator into water and discharge it from the system.
Vacuum pump: used to maintain the vacuum state inside the evaporator, reduce the boiling point of the solution, improve evaporation efficiency, and also facilitate the processing of heat sensitive materials.
Control Center: Implement automated control of the entire multi effect evaporator system, including control of feed rate, heating temperature, discharge concentration, and other parameters to ensure stable operation of the system.
Technological Process
Parallel flow: The flow direction of materials and steam is the same, both flowing from the first effect to the final effect in sequence. The solution automatically flows from the front effect with higher pressure and boiling point into the back effect with lower pressure and boiling point, and self evaporation occurs in the back effect, which can vaporize more water. However, as the solution flows from the front effect to the back effect, the temperature decreases and the concentration increases, which may increase the viscosity of the solution and decrease the heat transfer coefficient of the evaporator.
Reverse flow: The flow direction of materials and steam is opposite, with materials entering from the final effect and flowing sequentially towards the previous effect, while steam flows from the first effect to the final effect. As the concentration of the solution increases with the direction of flow, the temperature also rises, causing the viscosity of the solution to remain relatively constant and the heat transfer coefficients of each effect to be roughly the same. However, the flow of the solution between effects requires pumping, and the amount of secondary steam generated is relatively small.
Mixed flow: Combining the characteristics of forward and backward flow, the material adopts forward flow in certain efficiency intervals and backward flow in certain efficiency intervals, flexibly combining according to material characteristics and process requirements to achieve the best evaporation effect.
Advection: The material enters the evaporator of each effect in parallel, and the secondary steam generated by each effect also flows parallel to the condenser. The solution does not need to flow between effects and is suitable for handling materials that are prone to crystallization during evaporation.
Advantages and Characteristics
High energy efficiency: It can reuse heat in multiple evaporation processes, with an energy efficiency of over 60%, significantly reducing energy consumption.
Reduce operating costs: By improving energy efficiency and reducing raw material waste, production costs have been significantly reduced.
High concentration efficiency: capable of achieving high concentration in one device, improving production efficiency and output, suitable for large-scale industrial production.
Reduce water waste: Using a multi effect evaporator can achieve water recycling and reduce industrial water demand.
Environmental benefits: The use of multi effect evaporators can reduce the discharge of exhaust gas and wastewater, which meets the requirements of sustainable development.
Application Area
Chemical industry: used for evaporation concentration, crystallization and other processes of various chemical solutions, such as salt water concentration and purification of chemical raw materials.
Pharmaceutical industry: suitable for concentration and crystallization of drug solutions, as well as concentration of traditional Chinese medicine extracts, which can meet the requirements of temperature, purity, etc. in the pharmaceutical process.
Food and beverage industry: can be used for the concentration of fruit juice, milk, coffee, etc., which can better preserve the nutritional content and flavor of food during the concentration process.
Environmental protection industry: commonly used in
Sewage Treatment to separate harmful substances from wastewater through evaporation and concentration, achieving water resource recycling and pollutant reduction.
Jinkebotong Environmental Protection Technology (Jiangsu) Co., Ltd
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