More Effective Clarification of Circulating Water at Coke Plants

2019 ◽  
Vol 62 (10) ◽  
pp. 474-480
Author(s):  
S. S. Dushkin ◽  
O. P. Galkina
Author(s):  
Olena Pavlivna Galkina

In the work, on the basis of the data of the analysis of theoretical works and the laboratory studies carried out, the prediction of the values of corrosion rates in the circulating systems of coke plants was carried out using the Langelier and Ryznar stability indixes. The laws governing changes in the thermal stability of water as a function of temperature and water quality indicators (pH, alkalinity, total salinity, calcium ion content) have been established. Analysis of the obtained data showed that there is a clear dependence of the scale-corrosion properties of water on temperature and its chemical composition. A stable and effective supplying water composition for the circulating water supply system of the Kharkiv Coke Plant has been established.


Author(s):  
N. S. Tsarev ◽  
V. I. Aksenov ◽  
I. I. Nichkova

To neutralize the waste pickling solutions and rinsing water, resulting from cleaning metal products s surface of rust by acids solutions, lime is used. Being cheap, this method of sewage neutralization has considerable drawbacks. Forming in the technological pipes strong gypsum depositions and low specific productivity of the equipment for sediment dewatering are most significant of them. Characteristic of aggressive industrial sewage, formed at pickling of ferrous metals presented. Methods of elimination of drawbacks of industrial sewage neutralization by lime considered, including stabilization of neutralized industrial sewage and control of properties of the sediment formed. It was noted, that stability of the circulating water can be provided by accelerating of crystallization of the forming gypsum sediments by introducing in it fine priming powder and heating the neutralized water up to 65-70 °С followed by thermal softening of a part of circulating water, removed out of the circulating system. It was shown, that the heating of the water and the ongoing changes of the composition and properties of the sediment result in decrease of filtration resistance 2-3 folds, increase of deposition speed 3-4 folds and decrease the sediment volume 1.5-2 folds comparing with lime neutralization in cold water. Calculated dozes of lime at the heating were taken the same as at the regular lime neutralization. Elimination of the circulating water oversaturation by bi-water gypsum can be reached also by addition into the water of powder-like gypsum pulp - priming powder for microcrystals of the gypsum, followed by aeration during 30-40 min. This method was tested under industrial conditions. Technological properties of the forming sediment can be improved by sediment treatment by flocculants and preliminary heating of the neutralized water up to 65-70 °С. Control of technological properties of the sediment is done by addition of flocculants and heating of the neutralized water. Recommendations for improving operation of the neutralization facilities presented with indicating particular technological parameters of the equipment operation for sewage and sediment treatment. 


2020 ◽  
Vol 63 (7) ◽  
pp. 351-355
Author(s):  
V. I. Zasel’skiy ◽  
D. V. Popolov ◽  
G. L. Zaytsev ◽  
D. V. Sagalay
Keyword(s):  

2013 ◽  
Vol 37 (11) ◽  
pp. 1750
Author(s):  
Bin HUANG ◽  
Bin LIU ◽  
Jilin LIE ◽  
Jieming ZHAI ◽  
Kuoqiu YAN ◽  
...  

2003 ◽  
Vol 69 (7) ◽  
pp. 4123-4128 ◽  
Author(s):  
R. T. Bacon ◽  
J. R. Ransom ◽  
J. N. Sofos ◽  
P. A. Kendall ◽  
K. E. Belk ◽  
...  

ABSTRACT The heat resistance of susceptible and multiantimicrobial-resistant Salmonella strains grown to stationary phase in glucose-free tryptic soy broth supplemented with 0.6% yeast extract (TSBYE−G; nonadapted), in regular (0.25% glucose) TSBYE, or in TSBYE−G with 1.00% added glucose (TSBYE+G; acid adapted) was determined at 55, 57, 59, and 61°C. Cultures were heated in sterile 0.1% buffered peptone water (50 μl) in heat-sealed capillary tubes immersed in a thermostatically controlled circulating-water bath. Decimal reduction times (D values) were calculated from survival curves having r 2 values of >0.90 as a means of comparing thermal tolerance among variables. D 59°C values increased (P < 0.05) from 0.50 to 0.58 to 0.66 min for TSBYE−G, TSBYE, and TSBYE+G cultures, respectively. D 61°C values of antimicrobial-susceptible Salmonella strains increased (P < 0.05) from 0.14 to 0.19 as the glucose concentration increased from 0.00 to 1.00%, respectively, while D 61°C values of multiantimicrobial-resistant Salmonella strains did not differ (P > 0.05) between TSBYE−G and TSBYE+G cultures. When averaged across glucose levels and temperatures, there were no differences (P > 0.05) between the D values of susceptible and multiantimicrobial-resistant inocula. Collectively, D values ranged from 4.23 to 5.39, 1.47 to 1.81, 0.50 to 0.66, and 0.16 to 0.20 min for Salmonella strains inactivated at 55, 57, 59, and 61°C, respectively. zD values were 1.20, 1.48, and 1.49°C for Salmonella strains grown in TSBYE+G, TSBYE, and TSBYE−G, respectively, while the corresponding activation energies of inactivation were 497, 493, and 494 kJ/mol. Study results suggested a cross-protective effect of acid adaptation on thermal inactivation but no association between antimicrobial susceptibility and the ability of salmonellae to survive heat stress.


2021 ◽  
Vol 676 (1) ◽  
pp. 012099
Author(s):  
Yao Yang ◽  
Xiaona Li ◽  
Xiang Li ◽  
Yuchao Li ◽  
Tianqi Meng ◽  
...  

Author(s):  
Eugene Grindle ◽  
John Cooper ◽  
Roger Lawson

This paper presents an assessment of heat injection as a means of improving natural draft cooling tower performance. The concept involves injecting heat into the cooling tower exit air/vapor stream immediately above the drift eliminators in order to increase the difference between the density of the exit air/vapor stream and the ambient air. The density difference between the air/vapor in the cooling tower stack and the ambient air is the engine that drives airflow through the cooling tower. The enhancement of the airflow through the cooling tower (the natural draft) results in more evaporation and thus lowers the circulating water temperature. Because the heat is injected above the drift eliminators, it does not heat the circulating water. To evaluate the cooling tower performance improvement as a function of heat injection rate, a thermal/aerodynamic computer model of Entergy’s White Bluff 1 & 2 and Independence 1 & 2 (approximately 840 MW each) natural draft cooling towers was developed. The computer model demonstrated that very substantial reductions in cold water temperature (up to 7°F) are obtainable by the injection of heat. This paper also discusses a number of possible heat sources. Sources of heat covered include extraction steam, auxiliary steam, boiler blow-down, and waste heat from a combustion turbine. The latter source of heat would create a combined cycle unit with the combination taking place in the condensing part of the cycle (bottom of the cycle) instead of the steam portion of the cycle (top of the cycle).


2019 ◽  
Vol 29 (10) ◽  
pp. 1346-1358 ◽  
Author(s):  
Sebastian Englart

This study discusses the use of a membrane module for semi-direct evaporative air cooling. A cross-flow membrane module was used to carry out this air treatment process. For such a flow, it was proposed to describe and solve the heat and mass transfer model as a one-dimensional problem. The mathematical model was used to determine the moisture content and air temperature at the outlet from the module and the temperature of the circulating water. Results obtained using the proposed model are in good agreement with the experimental data. The relative error for the air temperature at the module outlet did not exceed 0.5%. For the moisture content, the relative error did not exceed 4%. For the circulating water temperature, the relative error did not exceed 0.6%. This paper also discusses the heating efficiency of the evaporative cooling process. Methods for determining the unit cooling indicator and the energy efficiency ratio are also proposed.


2017 ◽  
Vol 76 (8) ◽  
pp. 1981-1991 ◽  
Author(s):  
Lili Jiang ◽  
Xiayan Yao ◽  
Haitao Yu ◽  
Xingang Hou ◽  
Zongshu Zou ◽  
...  

Effect of a permanent magnet field on the scale inhibition property of circulating water was investigated. Orthogonal experiments of L16(45) were performed and analyzed using the range analysis method. The operating parameters included magnetic field intensity, initial concentration of Ca2+ and Mg2+, magnetic treatment time, temperature, and flow velocity. Scale inhibition rate, hardness, relative variation in the proportion of free water molecules, electrical conductivity, and relative variation of molecular energy were chosen as the objectives. In addition, the morphology and the composition of CaCO3 and MgCO3 scale were studied by X-ray diffraction analysis. The optimal conditions were initial concentration of 900 mg/L, magnetic field intensity of 0.5 T, temperature of 303 K, time of 54 h and flow velocity of 0.17 m/s. The nuclear magnetic resonance results demonstrated that the number of hydrogen bonds increased between water molecules and hydrated ions. The magnetic field can promote the increase in the number of hydrogen bonds, which can inhibit the formation of calcium and magnesium carbonate precipitation. Moreover, the ratio of calcite, aragonite and vaterite will be changed at different magnetic field intensities, and the aragonite ratio will reach the peak at the optimum conditions.


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