Influence of the apex angle of coned shaped tubes on particulate fouling of heat exchangers

A 2D cone shape has been added to the normal circular tubes of heat exchangers to minimize the area of stagnation and to stream line the air flow around the heat exchanger tubes. An experimental setup has been developed to study the influence of the apex angle of the cone shaped tubes on particulate fouling of heat exchangers. Fouling experiments have been performed in which calcium carbonate particles are injected during the experiments and the depositions of particles on the tubes of the heat exchanger is monitored. Four sets of experiments have been performed, in which normal cylindrical tubes and coned tubes with an apex angle of 60, 90 and 120 dgrs are examined. It was found that particulate fouling ceased if the apex angle of the cone shaped tubes is smaller than 90 dgrs. The attached cones enhance the flow around the tubes of the heat exchanger, i.e. by minimizing the stagnation area and keeping the flow attached to the tubes starting from the tip of the attached cone until separation, such that particles which deposit on the top of the tubes of the heat exchanger can be removed by the air flow