Fluidized bed scrubber: operating principle and applications
There is an opinion that modern fluidized bed scrubbers replace venturi/packed scrubber systems because they allow solving fouling problems, increasing capacity, adding particulate removal capability, and controlling environmental conditions. The thing is that fluidized bed scrubber systems demonstrate efficient removal of PM10 and PM2.5 particulate resulting in high-efficiency gas absorption.
The principle of bed scrubber operation is based on the entering of gas with particulate pollutants to gas inlet, then flowing upward. “Scrubbing liquid is introduced through fully open non-clog pipe distributors onto the surface of the induced fluidizing grid”. Fluidized bed scrubber may include single or multiple grid stages depending on the number of transfer units in order to provide the required particulate removal efficiency.
Additionally, the gas of high speed in the fluidized bed scrubber system moves in an angular upward path and fluidizes the liquid on the large open area grid surface. Compared to traditional scrubbers, fluidized bed scrubber uses swirl inducing vanes to considerably increase mass transfer and particulate pollutant collection. Modern fluidized bed scrubber systems include beds of low-density spheres.
“Liquid is introduced by way of spray headers at the top of the unit and travels downward while the gas to be reacted travels upward, countercurrent to the liquid flow. Gas velocities and liquid flow rates are maintained so that the sphere bed fluidizes (elevates, agitates, rotates) in the gas stream. This fluidization permits high flow rates of gas and liquid through the vessel. ”
Moreover, such fluidized bed scrubbers can operate at gas velocities varying from 50o to 1300 FPM, with liquid flow rates up to 75 gpm/sq.ft. without flooding. These bed scrubbers offer the following advantages:
- high soluble gas absorption because of exceptional transfer parameters of the fluidized bed scrubber systems;
- efficient collection of such particulates as dust, tars, oils, and suspended particles without plugging or channeling;
- high level of gas and liquid throughputs;
- low-pressure drop operation of the bed scrubber;
- wide range of fluidized bed operation.
Thus, fluidized bed scrubbers provide gaseous and particulate pollutant removal in the chemical, pharmaceutical, pulp & paper, semiconductor, fertilizer, minerals, petroleum, and food industries. Also, the applications of bed scrubber systems include acid gas collection from thermal oxidizers, chlorine dioxide and sulfur dioxide removal in pulp and paper bleach industries, acid and alkali fume air treatment from pickling, galvanizing, and cleaning lines including HCL regeneration plants in the metals industry, etc.
If you would like to make your contribution to improving air quality in order to provide air pollution control, you should choose a new type of wet scrubbers that is Multi-Vortex scrubber. Multi-Vortex wet air scrubber could apply water contaminated with dust, sand, and even small rocks to capture particulate matter, different types of dust and some gases from the air.