PROCESS AND DEVICE FOR TRANSFERRING GAS IN A LIQUID APPLICABLE IN PARTICULAR TO WATER TREATMENT, BIOTECHNOLOGY AND THE CHEMICAL INDUSTRY

摘要

The flow passage for liq. is designed so that liq. pressure is reduced as the liq. approaches the gas injection zone. Here, gas is injected at a very high speed, e.g. several hundred metres per second. The injection of gas is cocurrent with the flow of liq. and at an angle of incidence which is very low, pref. below 10 deg., w.r.t. the axis of flow of the liq. The mixt. advances through an expansion zone of the passage to form a fine emulsion. The pressure in the liq. is then raised to a level which remains lower than the pressure at which liq. is admitted to the mixer. Pref. the mixer passage converges in cross-section as it approaches the injection zone. Immediately downstream of the injection zone the passage is non-convergent where a confluence of fluids takes place. The confluence zone is followed by a divergent length of passage leading to a chamber where undissolved gas is recovered and from which it can be recycled. The mixer can be used for a wide range of gas/liq. contacting applications, e.g. oxygenation of waste water, carbonating drinks, introducing chlorine and ozone for disinfection. Also in the pharmaceutical industry for injecting gas into biological reactions. Very short contacting time reduces energy requirements. Minimal wastage of undissolved gas.