Vertical One Pass (VOP) heat exchangers are many times applied in urea plants. As the residence time in these heat exchangers is small, unwanted side reactions like biuret formation and hydrolysis of urea are limited. Liquid enters the tubes of the heat exchanger at the bottom side via a control valve. Due to the pressure drop over this control valve some flashing will occur. Furthermore the heat input from the shell side also will result in gas formation. The gas causes a turbulent environment at the tube side increasing the heat exchange co-efficient.
UreaKnowHow.com offers a very reliable and maintenance friendly solution to improve the performance of VOP Heat Exchangers. This solution have been proven for more than five years and increases the performance and reduces the fouling tendency in medium and low pressure recirculation heaters and evaporation heaters. The restriction orifices are very easy and quick to install and remove during a shut down