Blending includes the prevention of stratification in blended products, elimination of solidification and crusting at the product surface, heat transfer for uniform product temperature and blending of two miscible fluids.
All of these applications require basically the same approach with respect to fluid flow patterns and mixer horsepower ratings. It is generally accepted that the most desirable flow pattern in blending operations is a slight horizontal "swirl" combined with considerable vertical turnover.
To accomplish this, the mixer is installed at a slight angle with respect to the tank center line. This angle will vary from 10 in large tanks to 7 in small tanks. In most cases it is desirable to locate the mixer close to and clockwise from the fill line.
Operating procedure is one of the most important factors affecting blending applications. When writing specifications. When writing specifications, engineers should give special attention to this as required horsepower in identical tanks may vary greatly due to different procedures. |
