Study On Particulate Trapping And Energy Dissipation Of Vertical Multi-tube Scrubbers

Dust contamination control is one of main emphasis and difficult point of construction of “green mine”.Bag filter purify,spraying dust-settling and water bath scrubber dedusting are mainstay of mine dust control at present,the water bath scrubber performance better relative to their economic indicator.Since the shortages of operation unstable,serious secondary pollution and inefficient energy transform are existing in water bath dedusting technology,it is essential to develop a high efficiency and low energy consumption dust collector and technique for mine environmental protection.A vertical multi-tube scrubber(VMTS)has been designed in this paper.Quarry dust and coal dust were used as experimental dust which surface character is hydrophilic and hydrophobic respectly.Based on the theory of computational fluid dynamics,aerodynamics and mesoscopic scale mechanics theory,the coupling of gas-liquid-solid multiphase flow,the characteristics of air distribution in water bath tubes,the motion behavior of dust particles and the dust capture behavior in the air flow field are calculated and analyzed.The effects of primary liquid level,airflow and throttling height on the characteristics and change rules of VMTS’s gas-liquid coupling pressure fluctuation,energy consumption and dust capture rate were investigated.Based on interfacial chemistry method,the modification of dedusting liquid was studied,and the effect of dedusting liquid modification on the performance of VMTS was also investigated.The model of adhesion and desorption of dust particles-liquid membrane has been established.Results shows that dust particle that size is less than 50mm have strong self-adhesive property;furthermore,the dust density smaller the self-adhesive property is more significant;on the condition of RH > 65%,self-adhesive property of quarry dust is greatly improved,it was captured when adhere with water membrane;the coal dust is repulsive by the water membrane,and the smaller the particle size is,with the effect of the repulsive force between liquid membrane and coal dust particle,it is to more difficult for liquid membrane to capture small size particles.The gas-liquid coupling characteristics of VMTS has been investigated.The results show that there is a linkage phenomenon between the scale of the cavitations under the bottom of water bath tubes and the fluctuation of the pressure fluctuation;resonance phenomenon occurs when the coupling frequency is similar to the frequency of liquid pool;at the same time,the energy consumption and the efficiency of VMTS decrease;with a porous throttle plate which throttling intensity is 0.298 incorporation above the liquid tank,the liquid pool resonance can be suppressed effectively.The effects of structural parameters and operating parameters on the performance of VMTS are investigated.The results show that the comprehensive energy consumption of VMTS is inversely proportional to the cross sectional area of air flow path,and is directly proportional to the airflow and the primary liquid level.The energy dissipation rate is negatively correlated with the airflow and positivelycorrelated with the liquid level.The rate of respirable dust collecting efficiency and total collecting efficiency are increased after the throttle plate was incorporated in VMTS.The modification of the dedusting liquid and its effect on the performance of the throttle type VMTS has studied.The results show that the best formulation of the dedusting liquid was W106:AOE-15=0.12%: 0.06%;with modified dedusting liquid adopt,the collecting efficiency of the throttle type VMTS to dust C increased by4.6~6.2 percentage point,the total energy consumption decreased by 2.3%~2.7%,and the energy dissipation rate increased by 7 percentage points to 83%.The study also found that the the main reason of restricting the efficiency of wet scrubber dust collecting include "avalanche effect",imbalance of liquid level and wettability of dust by dedusting liquid;gas-liquid coupling resonance is the important reason for the energy utilization inefficient;to solve the above problems,the methods include incorporate throttle plate according to optimal throttling height and dedusting liquid modifying have been proved to be feasible.This paper has laid a key theoretical basis for the industrial application of vertical multi-tube scrubber.