节点文献
工业酸雾的实验室模拟与检测系统的建立研究
【作者】 赵佳；
【导师】 孙彦琳；
【作者基本信息】 昆明理工大学 ， 工业催化， 2021， 硕士
【摘要】 在许多金属制品加工过程中,通常会产生大量酸雾,弥漫在生产车间或是扩散至大气中,影响工厂周边居民的生活环境,破坏生态环境,而抑制工业酸雾的方法研究要得以顺利进行需了解工业酸雾在实际工业中的产生量化关系,而建立通用性较强且可在实际生产车间进行酸雾检测的检测方法具有重要意义。目前,对于酸雾定量方法的研究常见的取样方式是抽气取样,采用抽气的方式对酸雾进行抽出再用过滤器或是相关化学溶液吸收,采用化学滴定法、分光光度法、离子色谱法对其检测,但是上述方法均存在取样器成本较高,时间较长,且单种检测或取样的方法通用性受限,某些酸雾取样方法只能针对特定的酸雾种类进行取样,不具有普遍适用性,关于可系统的模拟酸雾产生并进行检测的完整研究也相对较少,因此本论文设计了抽气取样检测及滤纸取样检测两种酸雾检测方法可用于在实验室条件下或是工厂车间内检测酸雾量的检测方法,并对这两种方法的有效性进行验证,利用该方法系统探究了通气流量、通气时间、酸雾分布高度等因素对单位空间内酸雾分布的影响规律,同时对实验室前期提出的pH试纸法检测酸雾进行对比分析,得出主要结论如下:（1）论文第三章主要探究酸雾定量检测方法的建立及其方法对比,讨论抽气方法对酸雾取样检测及滤纸方法对酸雾取样检测两种方法,结合前期课题组建立的使用pH试纸检测酸雾做出定性分析的方法,对比使用pH试纸、抽气取样酸雾检测、滤纸吸收酸雾检测方法,得出使用pH试纸检测酸雾具有定性分析作用,较为直观。在抽气方法对酸雾取样检测方法中,课题组设计酸雾吸收塔,放置碱液对酸雾进行吸收,酸雾吸收效率受塔结构影响较大,而采用碱液对酸雾进行吸收时发现引起碱液浓度发生变化的影响因素除了酸雾本身以外,还有CO2及空气中含酸杂质的影响;采用滤纸方法对酸雾取样检测方法,可排除CO2及空气中含酸杂质的影响,并得出使用滤纸法检测单位空间内酸雾分布量得到最低的检测值为0.098126mg/m3,该检测值低于硫酸雾排放国家标准20mg/m3,该检测方法的误差限最大为±26%,最小为±0%。（2）论文第四章探究了对于实验室自行组装的模拟工业酸雾产生的装置中,调节通气流量及通气时间对酸雾分布量的变化规律,在实际酸雾产生工业中酸雾产生量主要取决于酸液内气泡的炸裂形式及酸内的气泡数和气泡尺寸,在实验室组装模拟酸雾产生装置中,可通过调节通气流量及通气时间对酸雾气泡进行宏观调控,本章实验得出的单位空间内的酸雾分布量增加,且通气流量及通气时间与单位空间内的酸雾分布量呈绝对的线性增加关系。（3）同时,在论文第四章说明了酸雾的扩散以空气为介质扩散,在由低到高的扩散过程中,单位空间内的酸雾分布量呈梯度减少,为研究随着高度的变化酸雾扩散规律,课题组以酸液表面为零点,以5cm为间隔高度,探究5cm至酸雾产生装置的最高点30cm处得出酸雾的产生形式区域,由于气泡炸裂产生一定能量造成酸雾液滴向上喷溅,同时受尺寸较大的液滴受自身重力的影响上升之某一高度又降落至酸液里,尺寸较小的液滴,重力较小容易形成气溶胶容易随着空气扩散,针对酸雾这种特征课题组以酸液表面为零点,以5cm为间隔高度,探究5cm至酸雾产生装置的最高点30cm处得出酸雾的产生的分布区域,0-15cm区域的酸雾产生主要是气泡炸裂的溅射液滴,15-30cm区域的酸雾主要是尺寸较小可随气流流动的酸雾液滴;同时在酸雾以溅射为主产生的区域（0-15cm）中,通气时间及通气流量都对单位空间内的酸雾量增加有一定影响,但高度为10cm以上的单位空间内的酸雾量增加趋势不明显,随着时间增加也并未增大,而是基本相近;在酸雾以扩散为主产生的区域（17.5-30cm）,通气时间及通气流量都对单位空间内的酸雾量增加也有一定影响,通气流量及通气时间不变时,高度为27.5cm与30cm的单位空间内的酸雾分布量检测数据一致;单位空间内的酸雾分布量与高度的关系实验探究中,多次实验均指向一个结果,即酸雾量随高度的分布关系成指数型的函数规律在逐步下降,15cm-20cm这一高度区域内可能是容易沉降的尺寸较大的酸雾液滴与可随空气流动的尺寸较小的酸雾液滴两者之间的交介区域,说明对于实验室自行组装的酸雾产生装置而言,大量会沉降的酸雾液滴在该区间以下已经沉降,该区间以上的酸雾大部分是可随空气扩散的酸雾。（4）第五章初步介绍了实验室自行建立的使用聚合物微球抑制酸雾的抑雾效率的初步探究,使用聚合物微球进行抑雾效率的初步探究的实验中,使用滤纸检测酸雾的方法检测聚合物微球的抑雾效率,得出粒径为1.25<d≤1.6mm、1.6<d≤2mm的聚合物微球抑雾效率最好,能达到99%,微球粒径为0.45<d≤0.9mm的抑雾效率最差为77.81%。这说明使用聚合物微球抑制酸雾具有明显效果。
【Abstract】 In the processing of many metal products,a large amount of acid mist is usually generated,which diffuses in the production workshop or diffuses into the atmosphere,affecting the living environment of the residents around the factory and destroying the ecological environment.Research on methods to suppress industrial acid mist must be carried out smoothly.It is necessary to understand the quantitative relationship of industrial acid mist in the actual industry,and it is of great significance to establish a test method that is highly versatile and can be used for acid mist detection in the actual production workshop.At present,the common sampling method for the research on the quantitative method of acid mist is air sampling.The acid mist is extracted by air pumping and absorbed by filters or related chemical solutions.Chemical titration,spectrophotometry,and ion chromatography are used.However,all of the above methods have higher cost and longer time for the sampler,and the versatility of a single detection or sampling method is limited.Some acid mist sampling methods can only sample specific acid mist types.It does not have general applicability,and there are relatively few complete studies on the generation and detection of systemic simulation of acid mist.Therefore,this paper designs two acid mist detection methods,namely air sampling detection and filter paper sampling detection,which can be used in laboratory conditions.The detection method of the acid mist volume in the factory or workshop is verified,and the effectiveness of these two methods is verified.The method is used to systematically explore the influence of the ventilation flow rate,ventilation time,acid mist distribution height and other factors on the acid mist in the unit space.At the same time,a comparative analysis of the pH test paper method to detect acid mist proposed in the early stage of the laboratory,the main conclusions are as follows:（1）Chapter 3 of the thesis mainly explores the establishment of quantitative detection methods for acid mist and the comparison of methods,discusses the two methods of gas extraction method for acid mist sampling detection and filter paper method for acid mist sampling detection,combined with the use of pH established by the previous research team The method of qualitative analysis for acid mist detection by test paper is more intuitive.Compared with the method of using pH test paper,acid mist detection by air sampling,and acid mist absorption by filter paper,it is concluded that the use of pH test paper for acid mist detection has a qualitative analysis effect,which is more intuitive.In the method of sampling and detecting acid mist in the air extraction method,the research team designed an acid mist absorption tower to place lye to absorb the acid mist.The absorption efficiency of acid mist is greatly affected by the tower structure,and when lye is used to absorb the acid mist It was found that the influencing factors that caused the change in the concentration of lye were not only the acid mist itself,but also the influence of CO2 and acid impurities in the air;the filter paper method was used to detect the acid mist sampling method to eliminate the influence of CO2 and acid impurities in the air.And it is concluded that using the filter paper method to detect the distribution of acid mist in a unit space,the lowest detection value is 0.098126mg/m3,which is lower than the national sulfuric acid mist emission standard of 20mg/m3,and the error limit of this detection method is±26%.The minimum is±0%.（2）Chapter 4 of the thesis explores the changes in the distribution of acid mist by adjusting the ventilation flow and the ventilation time in a device that simulates industrial acid mist generation in the laboratory self-assembled,and the amount of acid mist produced in the actual acid mist generation industry Mainly depends on the burst form of the bubbles in the acid and the number of bubbles and the size of the bubbles in the acid.In the laboratory assembly of a simulated acid mist generator,the acid mist bubbles can be macro-regulated by adjusting the ventilation flow and ventilation time.The experiments in this chapter have The acid mist distribution in the unit space increases,and the ventilation flow rate and ventilation time have an absolute linear increase relationship with the acid mist distribution in the unit space.（3）At the same time,in the fourth chapter of the thesis,it is explained that the diffusion of acid mist uses air as the medium.In the process of diffusion from low to high,the distribution of acid mist in a unit space decreases in a gradient.To study the diffusion law of acid mist,the research team took the surface of the acid liquid as the zero point and the interval height of 5cm,and explored the area from 5cm to 30cm from the highest point of the acid mist generator to find the area of the acid mist generation form.A certain amount of energy was generated due to bubble bursting.This causes the acid mist droplets to splash upwards,and at the same time,the larger droplets rise to a certain height under the influence of their own gravity and then fall into the acid.Smaller droplets have smaller gravity and are easier to form aerosols.Based on the air diffusion,the research group for the characteristic of acid mist takes the surface of the acid liquid as the zero point and the interval height of 5cm,and explores the distribution area of acid mist generation from 5cm to 30cm from the highest point of the acid mist generator,0-15cm The acid mist generated in the area is mainly sputtering droplets with bubble bursting,and the acid mist in the 15-30cm area is mainly acid mist droplets that are small in size and can flow with the airflow;at the same time in the area where the acid mist is mainly generated by sputtering（0-15cm）,both the ventilation time and the ventilation flow have a certain effect on the increase of the acid mist volume in the unit space,but the increase trend of the acid mist volume in the unit space above 10cm is not obvious,and it does not increase with the increase in time.Increase,but basically similar;in the area where acid mist is mainly generated by diffusion（17.5-30cm）,both ventilation time and ventilation flow have a certain effect on the increase of acid mist in the unit space,and the ventilation flow and ventilation time remain unchanged At the time,the detection data of the acid mist distribution in the unit space with heights of27.5cm and 30cm are consistent;in the experimental exploration of the relationship between the acid mist distribution in the unit space and the height,many experiments point to one result,that is,the amount of acid mist varies with The relationship of the height distribution becomes an exponential function.The law is gradually decreasing.In the height area of 15cm-20cm,there may be two large-sized acid mist droplets that are easy to settle and smaller acid mist droplets that can flow with the air.The intervening area between the two indicates that for the self-assembled acid mist generator in the laboratory,a large number of acid mist droplets that will settle have settled below this interval,and most of the acid mist above this interval can diffuse with the air Acid mist.（4）Chapter 5 preliminarily introduces the preliminary investigation of the mist suppression efficiency of using polymer microspheres to inhibit acid mist in the laboratory.In the experiment of using polymer microspheres to conduct the preliminary investigation of mist suppression efficiency,filter paper is used to detect acid.The fog method detects the fog suppression efficiency of polymer microspheres,and it is found that polymer microspheres with a particle size of 1.25<d≤1.6mm and 1.6<d≤2mm have the best fog suppression efficiency,which can reach 99%.The particle size of the microspheres The worst fog suppression efficiency of 0.45<d≤0.9mm is 77.81%.This shows that the use of polymer microspheres to suppress acid mist has a significant effect.