Optimization of Slurry PH Value for Limestone Wet Desulfurization Technology
Based on limestone wet desulfurization spray scrubber technology, this paper explicitly introduces the ionization process of water in slurry, deduces controlled range of slurry PH value and equation of slurry PH value in slurry droplet by analyzing the main origin of H+ and OH-, and other factors that influence ionization balance of water in slurry, provides theories for simulation of slurry PH value and optimization in practical operation. Besides, it concludes the reasonable range of slurry PH value by analyzing various factors such as increasing SO2 removal efficiency, decreasing operation cost, dissolution of CaCO3, oxidation of SO32- andHSO3-, and relationship of slurry PH values between slurry surface and the undersurface, provides reference for optimization of slurry PH value in practice. Finally, an optimization experiment of slurry PH value is designed for#11FGD in Taiyuan co-generation power plant, and the slurry PH value is optimized effectively.
The Impact of the pH Value of Circulating Slurry on a Wet Flue-Gas Desulfuration Process
In a limestone-gypsum wet desulfuration system the pH value of circulating slurry is an important parameter that affects the performance of the desulfuration system.By using a parallel-flow orderly falling-film type wet desulfuration device,an experimental study was performed of the impact of the pH value of the circulating slurry on a limestone-gypsum wet desulfuration process.The experimental results indicate that a higher pH value of the circulating slurry will contribute to a higher desulfuration rate.However,the content of limestone in the slurry will undergo an increase accordingly.When the pH value of the slurry in the circulating channel is greater than 6.0,the content of limestone in the slurry will rise drastically.If the above pH value is less than 4.8,however,the desulfuration rate will markedly drop.Summing up the effect of the pH value of the circulating slurry on desulfuration rate and limestone content,one can conclude that the rational pH value of the slurry in the circulating channel should range from 4.8 to 6.0.
History, criminology and the ‘use’ of the past
This article considers why, despite an apparent congruence of subject matter and methodologies, the disciplines of sociological criminology and criminal justice history are not more closely aligned. It contends that intellectual traffic between the two fields is not usually limited by institutional barriers, nor is it a legacy of the disciplinary antipathy which existed between history and sociology in Britain during the mid-twentieth century. Rather, it is due to the different ‘purposes’ with which sociological criminologists and criminal justice historians imbue their work and to the differing disciplinary perceptions of the relationship between the past, present and future which result from this. These different ‘purposes’ are traced via a consideration of the paths of development of the two disciplines from the 1940s. The article concludes by proposing an arena for future collaboration between criminal justice historians and sociological criminologists.