A fluidized bed heat exchanger can solve fouling problems in shell and tube heat exchangers. Fouling can really be a burden for plant operators. It reduces heat transfer and can even lead to reduced production capacity. The effect of fouling can be illustrated by an application where quench water had to be cooled: The heat transfer coefficient dropped in a conventional heat exchanger to 50% in a period of only 20 days.
By applying a fluidized bed heat exchanger, the heat exchanger surface can be kept clean over time. For the same quench water case the cleaning frequency dropped from 12 times per year to 0.
Klaren International, a partner company to R.C. Costello Assoc. Inc., provides fluidized bed heat exchangers for various markets ranging from the chemical industry, mining, geothermal energy and refineries.
In a fluidized bed heat exchanger particles made of glass, ceramic or stainless steel and with a typical size between 2-4 mm are added to the process fluid. In the vertically oriented heat exchanger tubes the particles are fluidized. The fluidized particles have a chaotic movement and thereby impact with the tube wall giving a light scouring action preventing a layer to develop but without eroding the tube.
Besides keeping the surface clean, the particles also have a second positive effect: they improve heat transfer. Heat transfer is improved because the fluidized particles in their chaotic movement break up the boundary layer. Even with the low fluid velocities of between 0.5 and 0.8 m/s, as applied in the fluidized bed heat exchangers, the heat transfer coefficient of the fluid stream with the fluidized bed is 10-20% better than for regular shell and tube heat exchanger operating between 1.5 and 2 m/s.
A fluidized bed heat exchanger can also provide a solution for your fouling problem. The solution can be to replace the current heat exchanger or to revamp an existing shell-and-tube heat exchanger re-using the tube bundle, the in- and outlets and the existing pump. Let the engineers of R.C. Costello Assoc. Inc. and Klaren International assess your situation and come with a proposal to keep your heat exchanger clean.