Development and Research of New Media Jet Aeration Scheme in a Loop Bioreactor Producing Microbiological Products

Abstract

Jet aeration loop reactors are widely used in the chemical industry due to their high mixing intensity, possibility of significant saturation of medium with gases, and simplicity of scaling the processes when passing from laboratory equipment to industrial designs. However, to ensure the necessary amount of air in standard jet aeration schemes with ejectors, high pressure of the medium (up to 6 bars) is required in the reactor loop. This paper presents a newly developed scheme of jet aeration, based on mixing the pressure flows of medium and air supplied to the ejector by individual blowers. Experiment results of the new water aeration scheme showed that, for the formation of suspended matter in the ejector with an air content of 2–20 l per 1 l of water, a pressure of 0.3 bar in the reactor loop at an air pressure of 1 bar is sufficient. This allows usage of low-pressure pump and compressor, which form the basis for the energy consumption reduction and creates prerequisites for lowering the shear loads on a crop. The medium aeration rate during experiments was 0.220–0.266 vvm. It was found that, for each mode of joint operation of pump and compressor, it is possible to maintain a constant aeration rate, which is not significantly affected by the flowrate regulation of medium in loop.

Keywords

• pressure
• flow
• saturation
• mixing
• bioreactor
• ejector