Scraper evaporator design considerations

Selection of hot and cold fluid flow path for scraper evaporator

In tubular heat exchangers, the cold fluid and heat flow paths can be selected according to the following principles:

(1)Due to the easy cleaning inside the pipe, unclean and easy-to-scale liquid treatment should be carried out in the pipe.

(2)Corrosive fluids should be taken to avoid corrosion of the shell.

(3)In order to prevent the pressure on the casing, high pressure treatment should be carried out.

(4)Saturated steam should be taken from the shell side. Since the saturated steam is cleaner, the convective heat transfer coefficient is independent of the flow rate, and the condensed water is easily discharged.

(5)The coolant should be on the shell side to facilitate heat dissipation.

(6)If the temperature difference between the two fluids is large, for a rigid structure heat exchanger, it is recommended to reduce the thermal stress by transmitting a shell having a large convection heat transfer coefficient.

(7)Fluids with low flow and high viscosity should pass through the shell side.