Jiangsu Shuoyun Petrochemical Equipment Co., Ltd.

Products

Natural circulation evaporator

Product Features:

Natural circulation evaporator is one type of evaporation equipment. The circulation of solution inside the equipment originates from the density difference of solution in different zones under heating, together with liquid entrainment by moving vapor. It includes coil evaporator, standard (central tube) evaporator and external heating evaporator, etc.

The circulation velocity of solution in natural circulation evaporator is relatively low, generally less than 1 m/s. To prevent scaling and crystallization, heating tubes shall be operated under fully submerged condition. This evaporator is suitable for concentration of solutions with mild scaling tendency and low corrosivity. Its advantages are simple structure, easy fabrication and low power consumption. The disadvantages are low solution circulation speed, so it is not applicable for high-viscosity materials or feeds with abundant crystals. It cannot be cleaned in-place. Materials have long heat exposure time, hence not suitable for heat-sensitive materials.

Working Principle:

In natural external circulation evaporator, solution circulates driven by density difference of feed liquid. Liquid is heated inside tubes of the heating chamber, its temperature rises and density decreases. The density difference against cold solution in circulation pipes triggers circulating flow: liquid flows upward in heating tubes and downward in circulation pipes. The heated solution enters the evaporation chamber with sensible heat for flash evaporation and cooling, then flows down into circulation pipes for repeated heating and evaporation.