Model of water evaporation stage during drying of latex coatings

2021 ◽  
Author(s):  
Venkata Ramana Gundabala
2018 ◽  
Vol 7 (1.8) ◽  
pp. 185 ◽  
Author(s):  
Yousef Mubarak

Relatively pure and coarse crystalline potassium sulfate of about 52 wt % K2O content and almost chlorine free has been obtained by reacting commercial potassium chloride and commercial ammonium sulfate in a stirred tank reactor at moderately low temperature. To increase the yield of potassium sulfate to a reasonable value, an evaporation stage located between the reactor and the crystallizer is used. The main steps of the production process include dissolution, reaction, evaporation, crystallization, centrifuging, drying, and then cooling. It is found that the best operating parameters to produce potassium sulfate of good quality, quantity, and crystal size are 1:1 as KCl/ (NH4)2SO4 mole ratio, 60 ºC reaction temperature, 1 hour reaction time, about one third of the total water used in the dissolution step is to be evaporated, 10 ºC crystallization temperature, 1 hour crystallization time, and 160 and 60 rpm agitation speeds in the reactor and the crystallizer respectively. Applying these operating conditions, a potassium sulfate yield of about 78 % can be achieved. Also, a fully soluble complex salt as a mixture of ammonium chloride and potassium sulfate is obtained by further treatment of the mother liquor. Further concentration of the mother liquor by further water evaporation of about 40 wt % and then crystallization of the slurry at 25 oC can recover up to about 60 wt % of the remaining solid in the mother liquor as a complex salt. The total yield of potassium sulfate is found to be about 95 wt % and the whole value of the solid product obtained is about 79 wt %.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wang Yi ◽  
Chen Zhonghua ◽  
Yu Fei

The coalescing aid of propylene glycol phenyl ether (PPh) influences on the latexes system and its film formation process have been demonstrated in this paper. The latexes with different Tg are synthesized by seeded semicontinuous emulsion polymerization. The PPh have a significant impact on the water evaporation stage, in which PPh decreased the water evaporation rate for a low Tg latex system but accelerated the rate for a high Tg latex. This result was quantified using Routh-Russel model which was a useful model for the prediction of the latex particle deformation mechanisms. The different amounts of PPh can change the latex particle deformation mechanisms. The TGA results show that the PPh still exist in the latexes films during drying. The microstructures of the latex film which dry under 70°C with the PPh for different time display that the PPh can accelerate the polymer molecules motion and the diffusion rate for the latex coalescence stage.


2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Jiawei Liu ◽  
Yingzhi Xia ◽  
Hui Li ◽  
Guoping Hu ◽  
Mingming Hu

Embankment soil affected by saline can not only cause roadbed settlement, frosting, and road cracks but also cause corrosion and cracking of roadbed pipelines, which seriously affects the stability of the road. Water evaporation and dry cracking of the saline soil mainly cause soil swelling, poor water stability, and corrosive characteristics of the embankment soil. In this study, the evaporative cracking characteristics of soil with different saline concentrations were investigated. The results showed that the moisture content decreased linearly with the drying time in the early evaporation process, subsequently decreased slow down in the mid-term evaporation, and finally become got and remain a residual moisture content, which are 46.39%, 44.05%, 42.70%, and 40.27% with the increase of the saline concentration. The evaporation process with different saline concentrations in the soil can be divided into three stages: uniform evaporation stage, slow down evaporation stage, and equilibrium evaporation stage, which was consistent with the moisture content change. With the development of the drying time, the cracks gradually appeared on the soil surface, gradually deepened in the soil, and expanded the crack network. The development of cracks can be divided into three stages: the cracking preparation stage, the crack development stage, and the crack stable stage. The cracking began at high evaporation rate under high saline concentration, and the fractal dimension remained stable under similar saline concentration. The fractal dimension was gradually increased with the decrease of the moisture content and the increase of the saline concentration, respectively. The soil began to crack with larger moisture under high saline concentration. The drying cracks in the nature were consistent with the configuration of the cracks formed in the experimental results.


2005 ◽  
Vol 36 (5) ◽  
pp. 425-430 ◽  
Author(s):  
A. M. Pavlenko ◽  
B. I. Basok

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2021 ◽  
pp. 591-597
Author(s):  
Matthew C. D. Carter ◽  
Andrew Hejl ◽  
Samantha Woodfin ◽  
Brian Einsla ◽  
Miroslav Janco ◽  
...  

2021 ◽  
Vol 35 (3) ◽  
Author(s):  
Zhigang Sun ◽  
Guofeng Zhu ◽  
Zhuanxia Zhang ◽  
Yuanxiao Xu ◽  
Leilei Yong ◽  
...  

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