Читать книгу Agitator Design for Gas-Liquid Fermenters and Bioreactors - Gregory T. Benz - Страница 20

It is possible to invest the same power at different shaft speeds by using different impeller sizes. In essence, high shaft speeds use smaller impellers and low shaft speeds use larger impellers. There are process, mechanical, and cost implications to this decision, as described in Chapters 6 and 17 and Ref. [2]. So, when we choose an initial speed, we may have to go back and choose another, as in the decision diamonds in Figure 2.1.

Though not all gear drives match the American Gear Manufacturer’s Association (AGMA) standard speeds, they are a good place to start, prior to engaging in detailed mechanical design. The speeds relevant for agitator design, in rpm, are 30, 45, 56, 68, 84, 100, 125, 155, 190, 230, 280, and 350 rpm. Laboratory units may have considerably higher speeds than this range.