developments at Drexel Universitys Mechanical Engineering Department,
Philadelphia, Pennsylvania, have resulted in a new technology that both
prevents and eliminates scales in heat transfer surfaces.
Seven years of research with scientists in heat transfer and fluid
dynamics have improved the understanding of non-chemical water treatment,
specifically, electronic treatment. A
theory of operation has been developed based on well-founded laws of physics and
chemistry and validated through both lab testing and field-testing.
been numerous articles in well-respected scientific journals in
this field. The electronic
descaling technology can be found in the International Journal of Heat and
Mass Transfer, Compact Heat
Exchangers for the Process Industry and the 32nd National Heat
the last few years has resulted in a number of new patents being awarded in both
heat transfer and other sciences using the basic principles of electronic
descaling technology. This research
is the foundation for a better understanding of this technology and how it can
be successfully applied to solving mineral precipitation fouling that has
electronic descaling technology is based on the Controlled Precipitation
of scale forming mineral crystals. The
fouling problem begins with supersaturated water that contains excessive amounts
of mineral ions such as calcium and magnesium.
exchanger surfaces are negatively charged, pulling positively charged mineral
ions toward them. Precipitation
occurs when the water makes contact with the metal surfaces at high
temperatures. The solubility on the
ions decreases with increase temperature. These
ions stick to metal surfaces as a result of electrostatic attraction.
This is termed Uncontrolled Precipitation and is how scaling
The technology uses a square wave pulsing current, which creates an induced electric field within the feed pipe to the heat exchanger. This is known as Faradays Law. This induced oscillating electric field provides the necessary molecular agitation to charged ions and causes the excess mineral ions to undergo a precipitation. This precipitation is deliberately initiated by the molecular agitation away from the heat exchanger surface and is called Controlled Precipitation. A snowball effect begins resulting in larger insoluble crystals being formed.
As a result,
when supersaturated water is treated by the electronic descaling technology,
dissolved mineral ions are converted to insoluble mineral crystals and are
suspended in water and remain in the water without sticking to the heat
exchanger surface. Controlled
Precipitation reduces the number of dissolved mineral ions in the water and
subsequently eliminates fouling.
one problem that continues to frustrate industrial and commercial users and costs
industry millions of dollars in chemical clean up, downtime, process duplication
and reduced capacity each year. Proven
solutions will certainly change the face of the heat transfer industry today.