Catalogs >
NOV Inc. >
HE-3

HE-3
2Pages

Catalog excerpts

Chemineer™ HE-3 High Efficiency Impeller The Chemineer high efficiency (HE-3) impeller provides all of the benefits of more efficient agitation with very few design limitations. Improved agitation efficiency and greater process flexibility are now available with a practical, fabricated impeller. What is high efficiency agitation? In an engineering sense, high efficiency agitation means that the same process results are achieved with reduced mechanical or energy requirements. On the business side, high efficiency agitation means reduced capital and operating costs. The Chemineer high efficiency impeller is a result of extensive testing, and is supported by new technology for proper process application. The HE-3 impeller has three specially designed blades, mounted at a shallow angle, to provide a high degree of axial flow with minimal power requirements. Thus, the HE-3 impeller is able to create more liquid motion with less energy. An extremely efficient turbulent flow impeller for blending, heat transfer and solids suspension developed to minimize the creation of trailing vortices and incorporating the otherwise wasted energy into macro-flow. Process Efficiency Any successful agitator design must provide some required level of process performance. Although process performance has many meanings in the chemical process industries, agitator design has been quantified for most typical applications. Our ChemScale™ design procedure is one of the best methods for relating agitation intensity to process performance. The development of a high efficiency impeller does not change the concept of ChemScale; only the size of agitator required for a given process result changes. Although bulk fluid velocity, as defined in ChemScale, is a convenient means of characterizing agitation intensity, it is just an indirect measure of process performance. Both the magnitude and the direction of fluid velocities are important in agitation, and must be correctly related to process performance. Thus in addition to basic hydrodynamic measurements, extensive experience and testing with a variety of blending and solids suspension problems are behind each application of an HE-3 impeller. The effects of flow patterns are also important in determining impeller efficiency. The HE-3 impeller creates axial flow with less radial and rotational flow than a standard pitched blade (P-4) turbine. The discharge from the high efficiency impeller spreads less rapidly, thus allowing the impeller to be successfully placed farther from the bottom of the tank. Consequently, tank geometry is less of a factor in designs using an HE-3 impeller because the strong axial flow will control a wider range of liquid levels. Different agitator horsepower and speed combinations are capable of providing similar process performance with any one type of impeller in most applications. When different types of impellers are considered, even more equipment combinations will produce similar results. The agitator selections for two different process situations are shown in the tables on the reverse side. Four different agitators, capable of similar process performance using standard P-4 impellers, are compared with four agitators using HE-3 impellers for each situation. A smaller Chemineer HT agitator drive size is required for the same process results. Similar or lower horsepower motors can be used with the larger diameter HE-3 impellers. The benefits of a more efficient impeller delivering equivalent process performance are available for both new and existing applications. Many agitators can be updated by replacing standard P-4 impellers with HE-3 impellers to improve blending, heat transfer, or solids suspension.

Open the catalog to page 1

45° Pitch Bladed Impeller High Efficiency Impeller HE-3 Process Situation Results For each of two different process situations, eight equivalent ChemScale selections are shown. Each situation shows that several alternative horsepower and speed combinations are capable of similar results, but the efficient performance of the HE-3 impeller consistently reduces the drive size. Impeller Technology In some ways the axial flow produced by an agitator impeller is related to the thrust created by a marine or aircraft propeller. To create either axial flow or thrust, an impeller must impart momentum...

Open the catalog to page 2