| This dissertation first introduces status on the air pollution in China. Particles and SO2, emitted from the coal fired industrial boilers, still are main pollutions which have an effect on the urban air quality. At present, because wet flue gas desulphurization (WFGD) techniques were direct imported from abroad or assumed through purchase key equipment in China, high technical import cost and user charge need pay. Furthermore, the coal type, the economic and operated condition are different, we can not copy abroad WFGD technique. So it has distinctness society, economy and environment signification to develop and study the devices with autonomous intellectual properties, lower invest and operation cost,which are used to removal dust and desulphurization.The main work and novel results of this dissertation includes the following elements. (1) Based on amount home and abroad flue gas desulphurization and dust removal integrated device references, a new type of integrated installation - umbrella plate scrubber for dust removal and desulfurization from flue gas was developed, which possesses high efficiency in dust removal, desulphurization and other harmful gaseous purification and recycle use the scrubbed water. In addition, the device has a small-volume, low running cost and convenience maintenance. The device is suit to removal dust and desulphurization of the middle and small coal fire industrial boiler in China. (2) The experimental system was water-air-fly ash and the new type umbrella plate scrubber was studied through model experiment. Physical and chemical properties of the fly ash were tested firstly. Secondly, the leak rate of the device, pressure drop, collection efficiency, and energy consume were tested through experiment. The operation conditions included inlet gas velocity range of 10 - 18 m/s, dust concentration range of 2 - 22 g/m3, liquid and gas ratio range of 0 - 0.8 L/m3. The results showed that the pressure drop of the new type umbrella plate scrubber was about 250 - 750 Pa; when liquid and gas ratio was 0.2 L/m3, collection efficiency got up to 98.8%, energy consume was about 216 Pa. (3) Then the new type umbrella plate scrubber was studied through Computational Fluid Dynamics (CFD) simulation. After calculation zone was sured, the mesh generated through gambit software. The calculating grids had different size and spacing. SIMPLE arithmetic was selected. The velocity coupled pressure. The boundary conditions were set in terms of experimental, literature or experience data. k-εstandard model and Reynolds stress model (RSM) were use to simulate the continuous phase. Discrete phase model (DPM) was used for particle trajectories determination. The pressure drop and the collection efficiency of the new device were predicted through simulation. The simulation results show that the pressure drop of the new devices is 230 - 250 Pa and the efficiency is about 84-86%, with the inlet velocity equal to 10.6 m/s and the dust concentration ranging from 2 to 22 g/m3. The relative error of the pressure drop and the efficiency between simulative results and experimental data are approximately 4% and 10% respectively. With the inlet velocity equal to 12 m/s and the liquid and gas ratio is from zero to 0.8 L/m3, the simulation of gas-liquid two phases was unsteady through DPM model. The simulative results show that droplet keep a better cone-shaped pour figure. With time going, sprayed droplets begin to collide to umbrella plates, form liquid-film and rebound simultaneity. It could be observed that spray liquid possesses the better rectifier role on the gas flow. With the inlet velocity equal to 12 m/s, dust concentration is equal to 6.452 g/m3 and the liquid and gas ratio is from zero to 0.8 L/m3, the gas-liquid-solid three phase flow was simulated in the umbrella plate scrubber. The simulative results showed that liquid and gas ratio have a little effect on gas holdup in near wall and have a great impact on gas holdup inside the umbrella plates. And the gas holdup distributing is more even. The liquid-film can be full of the scrubber. Very few droplets were carried out by the flue gas. The volume fraction of the solid particle is bigger near the water tank. The removal dust effect is distinct. (4) The advanced non-contact Particle Image Velocimeter (PIV) technique was adopted to validate the simulative flow field. With the inlet velocity is 12 m/s, the gas flow field around the umbrella plates and inlet pipe were measured by PIV. The PIV measure results indicated that the turbulent flow is intense when the airflow rounded the umbrella plates, and forms a lot of small vortexes round the umbrella plates, which increases the contact surfaces, prolongs all kinds of phase residence time, benefits to separate and purify. There exist big vortex and circumfluence in the entrance to the scrubber. (5) Compare the performance test of the model scrubber, PIV flow field measure and the flow characteristic & performance through simulation, the result show that the flow orientation same between the simulation and PIV results. It has demonstrated that simulation is an effective method to predict and evaluate the performance of a new device, and visualize the flow field. The experiments not only provide parameters for the simulation, but also validate the simulative results. Simulation may provide instruct for the scrubber structure design and operation technique optimizing. (6) Pressure drop and efficiency similar modelling were declined through quanitity analysis. After the model scrubber was magnify ten fold, the simulation result show similar to the model scrubber in the velocity, pressure, DPM concentration distribution, and flow characterize. The similarity and modeling theory analysis of the umbrella plate scrubber provide theoretical foundation further for the engineering practice and amplification design.The dissertation has change the traditional design process, that is, small experiment- middle experiment - generalization. The flow detail particular may be obtained and the whole performance of the scrubber is predicted and evaluated through simulation combined with experimental method. Effective combination of two methods can sure the performance and visualize the flow field and strengthen understand of the flow disciplinarian, which have very strong engineering practice signification. Using simulation method can shorten device developed time and reduce experiment and design cost, which possesses a very good economic benefit. The simulation process complete through computer and reduce greatly experimental workload and decrease the environmental pollution, which have a good environmental benefit.
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