Helical Double-Pipe Heat Exchanger to Suppress Scale Precipitation

The patent applies local quality by forming irregularities (concave portions) at specific locations within the first pipe rather than uniformly throughout. The irregularities are concentrated in regions where water flow tends to stagnate, creating localized turbulence zones that prevent scale precipitation without compromising overall heat exchange performance. This selective placement allows the pipe to maintain good thermal transfer characteristics while addressing scale issues only where needed.

The patent converts the harmful effect of water stagnation into a beneficial effect by intentionally creating controlled irregularities that induce turbulence. The stagnation zones that would normally cause scale precipitation are transformed into regions with enhanced flow mixing, where the irregularities generate local eddies and turbulence that keep scale particles suspended and prevent their deposition on the pipe inner surface.

The patent employs mechanical vibration in the form of flow-induced turbulence generated by the irregularities on the pipe inner surface. The concave portions act as flow disruptors that create localized vortexes and turbulent eddies, mechanically agitating the water flow. This turbulence increases the kinetic energy of water molecules in the boundary layer, enhancing convective heat transfer coefficients and preventing the formation of stagnant thermal layers that would reduce heat exchange efficiency.

The patent utilizes hydraulic principles by designing the irregularities to exploit the fluid dynamics of water flow. The concave portions are positioned and dimensioned to create specific flow patterns, including recirculation zones and enhanced mixing, that leverage the natural properties of water as a fluid. This hydraulic design approach optimizes the interaction between the flowing water and the pipe surface geometry to maintain adequate flow velocity and prevent stagnation.