Pages

June 11, 2011

Cooling water treatment without chemicals

I came across an article in which mentions the elimination of chemicals and their associated handling hazards in the treatment of cooling water. The article mentions the following:
"To resolve many of the issues associated with chemical treatment, technologies using non-chemical treatment have been evolving. Non-chemical devices (NCDs) use many different technologies to achieve biological and corrosion control. Over 30 suppliers are known to provide commercially available products that can be grouped into four basic classes or methodologies: magnetic devices; induced electric field devices; ultrasonic devices, and mechanical energy devices.
How CHC Works
The CHC unit consists of a pressure equalizing chamber and a cavitation chamber. Inside the cavitation chamber, two pairs of nozzles are positioned opposite each other at specific distances, lengths, and angles. Water is first pumped into the pressure equalizing chamber at a pump pressure of ~70 PSI. From the equalizing chamber, water is channeled into the cavitation chamber, where water is forced to rotate with high velocities. The rotation of water streams creates a high vacuum, typically greater than -30 inch Hg. This high vacuum condition causes micro-sized bubbles to form in the water streams. These bubbles are filled with a mixture of vapor and dissolved gases. The water streams in two nozzles rotate in opposite directions. Meanwhile, the water streams travel forward at accelerating speeds. Upon exiting from the nozzle, the opposite water streams collide at the mid-point of the cavitation chamber. At this point, pressure increases spontaneously, causing the sudden implosion of micro-sized bubbles. At the moment of collapse, hydrodynamic cavitation generates intensive shocking waves and produces extremely high temperatures. Under these conditions, chemical reactions such as conversion of dissolved calcium and bicarbonate ions into calcium carbonate (CaCO3) and oxidation of organic compounds can occur. In addition, the bacteria in the water are ruptured by mechanical, physical and chemical forces".

Read the article and see the images in this link.

No comments:

Post a Comment