OPERATING RESULTS AND AEROSOL DEPOSITION OF A VENTURI SCRUBBER IN SELF-PRIMING OPERATION

This study deals with behaviour and washing efficiency of a venturi sc rubber in self-priming operation. Usually the washing liquid is inject ed into the throat by means of a pump, in such a way that the amount o f liquid added per cubic metre of gas is adjustable independent from t he gas flow rate. In contrast to this kind of design, the venturi scru bber used works via a self-priming operation, i.e. the washing liquid is injected by means of a pressure difference between the inside and o utside of the venturi throat as a result of the hydrostatic pressure o f the liquid and the static pressure of the flowing gas. As is well kn own from the literature, the cleaning efficiency of a venturi scrubber improves with the amount of liquid added per volume of gas and with i ncreasing gas velocity in the throat. However, high gas velocities and high charges of washing liquid cause a large pressure drop. Hence, th e separation efficiency and energy consumption of the scrubber have to be optimized. It is shown that the separation efficiency could be imp roved by a multistage injection of the washing liquid. Due to the self -priming operation, the separation efficiency remains at a high level even if the gas velocity decreases, and thus requires no regulation fr om the outside. Liquid separation after the venturi scrubber is realiz ed by an immersion tube in combination with swirl promoters in the dif fuser section of the scrubber which increase the rotation of the gas-l iquid flow. Thereby, droplets are pushed aside to the diffuser walls a nd are deposited.