US Patent 6875988 Germicidal lamp and purification system having turbulent flow

A germicidal lamp having a non-uniform contour increasing turbulence. An ultraviolet fluorescent lamp used in a purification system having a helical groove increasing turbulence of the fluid flow. The non-uniform contour may be placed directly on the tubular envelope forming the lamp or may be formed on a separate envelope enclosing a conventional cylindrical tubular germicidal lamp. The germicidal lamp having a non-uniform contour when placed in a fluid flow, such as water or air, creates turbulence, which improves the efficiency of the germicidal action. Smaller, more efficient purification systems requiring less exposure time are obtained.