Research On The Establishment Of Laboratory Simulation And Detection System Of Industrial Acid Mist

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.