Introduction:

    The central circulation tube evaporator is composed of vertical tube bundles with a thicker diameter tube in the center of the tube bundles. The heating surface of the unit volume of the solution in the thin tube is larger than that of the thick tube, that is, the former is heated well, and the solution vaporizes more. Therefore, the density of the vapor-liquid mixture in the thin tube is smaller than that in the thick tube. The continuous regular natural circulation movement of the tube ascending. The thick tube is called the downcomer or central circulation tube, and the thin tube is called the boiling tube or heating tube.

    Its heating chamber is composed of a vertical tube bundle with a tube diameter of 25mm-75mm and a length of 1m-2m (the ratio of length to diameter is about 20-40), and a thicker tube is installed in the center of the tube bundle. During operation, the heating area per unit volume of the solution in the tube bundle is larger than that in the thick tube, that is, the former is heated well and the solution vaporizes more, so the solution in the thin tube contains a lot of vapor, resulting in a density smaller than that of the solution in the thick tube. Prompt the solution to make a cyclic movement of falling along the thick tube and rising along the thin tube. Therefore, the thick tube is called the downcomer tube in addition to the central circulation tube, and the thin tube is called the heating tube or the boiling tube. In order to promote a good circulation of the solution, the cross-sectional area of the central circulation tube is 40%-100% of the total cross-sectional area of the heating tube bundle in the design.

Advantage：

    The central circulation tube evaporator is developed from the horizontal heating chamber and the coil heating chamber evaporator. Compared with these old-fashioned evaporators, it has the advantages of good solution circulation and fast heat transfer rate. At the same time, it is called "standard evaporator" because of its compact structure, convenient manufacturing, and wide application.

Application：

    The central circulation tube evaporator is suitable for evaporating solutions that are not serious and have a small amount of crystallization and less corrosiveness. The heat transfer area of this evaporator can be as high as hundreds of square meters, and the heat transfer coefficient is about 600w/(m.℃)-3000w/(m.℃).