The evaporator, preheater, separator, condenser, condensate tank, etc. are made into a multi effect falling film evaporator. The evaporator is a tubular heat exchanger, with the tube side used for the inflow and outflow of liquid and the shell side used for heating steam. The liquid material enters from the top of the evaporator and is distributed through a distributor into the heating tubes, where the liquid flows downwards along the heating tubes/Idle second-hand three effect evaporator set

In the process of separation. The characteristic of a preheater is its horizontal tube type hot gas. The tube side is connected to liquid materials, while the shell side is connected to secondary steam. The so-called secondary steam refers to the steam generated during the evaporation process. The role of a preheater is mainly reflected in two aspects: firstly, preheating objects entering the evaporator; The second is to cool the secondary steam for easy recycling and utilization. The single-layer structure of the separator is its main feature. The secondary steam interface is the same as the condenser interface, and the lower interface is connected to the evaporator. The condenser is the same as the preheater, both are horizontal tube and tube heat exchangers, with cooling water flowing through the tube side and the shell side connected to the shell side of the preheater. The condensate tank, like the separator, is a single-layer structure tank with a relatively simple tank structure. The tank is equipped with a level switch that can control the liquid level, allowing for one-to-one control of the liquid level. Its main function is to achieve automatic discharge of condensate in the tank by connecting the pump (pump at the outlet).

The working principle of the multi effect falling film evaporator is that the material solution enters the suction port of the circulation pump from the material pump, and the pump increases the pressure at this time. The solution enters the feed chamber of the evaporator after preheating, and then enters the heating tube for evaporation. After evaporation, it enters the separation chamber to separate the steam from the liquid material. The solution then flows into the suction port of the pump for circulation and utilization. The evaporated steam is separated from the concentrated liquid, and the secondary steam is recovered and reused by the condenser. When performing reverse flow operation, the operation is roughly the same. The outlet of the concentrated solution should be calibrated because the calibration temperature is high, which will reduce the viscosity of the solution and facilitate the production of higher concentration concentrated solution.

Characteristics of Multi Effect Mode Evaporator

The structure is relatively compact, the layout is also reasonable, and the footprint is small, making it easy to install; The high production efficiency is the characteristic of the multi effect mode evaporator, which has a huge evaporation capacity; The energy-saving effect of the multi effect falling film evaporator is very significant, with energy consumption about one-third of that of a typical mode evaporator. QMA is less than or equal to 0.44, QB/Q is less than or equal to 7.99, where Q refers to the evaporation of clean water, QA refers to the consumption of steam, and QB refers to the consumption of cooling water.

From the perspective of energy conservation, multi effect mode evaporators are widely used by most manufacturers in Xinjiang. For example, a factory in Xinjiang utilizes the working principle of a multi effect reduction mode evaporator to provide heat energy to other systems that require heating using secondary steam. This not only reduces the consumption of steam in the boiler, but also reduces the amount of secondary steam that does not enter the condenser to a certain extent, thereby improving the utilization rate of positive gas and enhancing the efficiency of the enterprise. The steam used in the multi effect falling film evaporator generally does not exceed 180 degrees Celsius. When the temperature of the steam exceeds 180 degrees Celsius, the pressure will increase, which will cause losses in equipment operation and unnecessary cost losses. Therefore, the main purpose of the multi effect falling film evaporator is to save heating steam.Idle second-hand three effect evaporator set

In high-efficiency evaporation, the steam generated by the previous evaporation can provide the necessary heating steam for the subsequent evaporation. Therefore, multi efficiency evaporation can save a lot of steam consumption. Multi effect evaporation will decrease as the number of calibrations increases, and the required amount of steam generated will also decrease with the same total evaporation amount, resulting in lower operating costs. But when there are too many schools, the cost of equipment also increases, and the amount of steam generated gradually decreases. In theory, excessive evaporation calibration is difficult to operate. Relatively speaking, the heating temperature of the effective steam in multi effect evaporation is limited, and the operation of its condenser is also limited to some extent. The theory of multi effect evaporation is also limited. Under certain operating environments and conditions, as the number of calibrations increases, the temperature difference between them also increases in a proportional relationship. Therefore, the effective temperature difference gradually decreases, forming an inverse relationship. When there are too many calibrations, the effective temperature difference decreases, and the temperature allocated between each effect is insufficient to ensure normal boiling of the liquid, further increasing the difficulty of the evaporation operation. The number of calibrations depends on the properties or characteristics of the evaporating material, such as electrolyte solutions. Due to their fast boiling point increase rate, using two or three effects is sufficient. For non electrolyte solutions and other materials with slower boiling point increase, four to six effects are required.

The solution process in a multi effect falling film evaporator can exist in parallel flow, parallel flow, countercurrent flow, and cross flow, and it is not difficult to choose one method among them. The selection should be based on the properties of the materials, the operating method, and the related costs. The Xinjiang example discussed in this article belongs to the counterflow mode, where the solution and steam form a counterflow. Based on the application examples of the falling film evaporator, three key points have been summarized: firstly, both the falling film and rising film methods need to be selected according to the properties of the material; Secondly, multi effect evaporators should be selected reasonably for the reason of energy saving; The confirmation of the multi effect evaporator process should be based on the characteristics of the evaporating solution

Since the invention of concentrators, they have been widely used in various fields such as chemical industry, medical production and processing industry, ore processing industry, sewage treatment, etc. The mainstream concentrators used in production are spherical concentrators, single effect concentrators, and double effect concentrators. Single effect concentrator is suitable for industrial alcohol recovery such as dairy products, and can be used for vacuum concentration with low heat sensitivity for small batches and multiple varieties. The dual effect concentrator is suitable for the concentration of materials such as Chinese, Western, starch sugar, and dairy products, especially for low-temperature vacuum concentration of thermosensitive materials. The spherical concentration tank is mainly composed of four parts: the main body of the concentration tank, the condenser, the gas-liquid separator, and the liquid receiving tank. Due to the use of pressure reduction concentration, the concentration time is short and the effective components of thermosensitive materials will not be destroyed.