Modeling CaCO3 crystallization fouling on a heat exchanger surface – Definition of fouling layer properties and model parameters

Pääkkönen, Tiina; Riihimäki, Markus; Simonson, Carey J.; Muurinen, Esa; Keiski, Riitta L.

doi:10.1016/j.ijheatmasstransfer.2014.11.073

Cited by 59 publications

(17 citation statements)

References 29 publications

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“…They concluded that this trend was an indication of the diffusion controlled mechanism. Paakkonen et al [41], however, showed a decrease in the mass deposition rate of calcium carbonate with an increase in the flow velocity.…”

Section: Effect Of Flow Velocitymentioning

confidence: 95%

“…Pääkkönen et al [41] suggested to include the effect of flow velocity by introducing time scaling factor to equation (3) to become:…”

Section: Deposit Ratementioning

confidence: 99%

“…The fouling rate increase in low-velocity regions, especially where the velocity drops suddenly [46]. Paakkonen et al [41] mentioned that the deposit rate increases as the residence time of the fluid increases (Low velocity). In MSF evaporated stages and heat exchangers in general, the evaporated tubes are connected to each other by water boxes where the velocity drops suddenly and thus more fouling is expected at the outlet tubes and on the shell side of the water boxes.…”

Section: Fouling Resistancementioning

confidence: 99%

“…However, further increase in the velocity results in decrease in the deposit rate of calcium carbonate. Though Brahim et al [22] reported that the heat transfer can be improved due to the increase in the velocity, Paakkonen et al [41] pointed out that reducing the resident time of the fluid at the surface may decrease the probability of the fouling material to stick to the surface. As it can be seen in Figure 15, the heat transfer was slightly improved with the increase in the velocity.…”

Section: Effect Of Flow Velocitymentioning

confidence: 99%

“…However, for diffusion controlled process, Andritsos et al [35] reported a weak effect of the fluid velocity on the activation energy of carbonate system. Paakkonen et al [41] found out that the effect of activation energy is much stronger than the effect of preexponential constant. In the present work, and due to the lack of experimental data for fouling in MSF process, values for k r0 and Ea for calcium carbonate were assumed to be (k r0 = 1.8x10 10 …”

mentioning

confidence: 99%

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Dynamic modelling of Heat Exchanger fouling in multistage flash (MSF) desalination

Alsadaie

Mujtaba

2017

Desalination

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Fouling on heat transfer surfaces due to scale formation is the most concerned item in thermal desalination industry. Here, a dynamic fouling model is developed and incorporated into the MSF dynamic process model to predict fouling at high temperature and high velocity. The proposed dynamic model considers the attachment and removal mechanisms in the fouling phenomena with more relaxation of the assumptions such as the density of the fouling layer and salinity of the recycle brine. While calcium sulphate might precipitate at very high temperature, only the crystallization of calcium carbonate and magnesium hydroxide are considered in this work. Though the model is applied in a 24 stages brine recycle MSF plant, only the heat recovery section (21 stages) is considered under this study. The effect of flow velocity and surface temperature are investigated. By including both diffusion and reaction mechanism in the fouling model, the results of the fouling prediction model are in good agreement with most recent studies in the literature. The deposition of magnesium hydroxide increases with the increase in surface temperature and flow velocity while calcium carbonate deposition increases with the increase in the surface temperature and decreases with the increase in the flow velocity.

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Section: Effect Of Flow Velocitymentioning

confidence: 95%

“…Pääkkönen et al [41] suggested to include the effect of flow velocity by introducing time scaling factor to equation (3) to become:…”

Section: Deposit Ratementioning

confidence: 99%

Section: Fouling Resistancementioning

confidence: 99%

Section: Effect Of Flow Velocitymentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Dynamic modelling of Heat Exchanger fouling in multistage flash (MSF) desalination

Alsadaie

Mujtaba

2017

Desalination

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An investigation on scaling failure of heat exchanger in cooling water system of natural gas purification plant

Jiang

Huang

Wang

et al. 2022

Asia-Pacific J Chem Eng

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In this study, a natural gas purification plant adopts open circulating water system, which cannot work properly and hinder the normal production of natural gas due to the problems such as scaling and blockage in the operation of heat exchanger device was reported. Qualities of the make‐up water and recirculating cooling water were evaluated by parameters such as hardness, alkalinity, pH, and conductivity. X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and optical microscope were employed to study the crystal structure, composition, and morphology of the scale deposits. The flow rate of the water in the tube bundle was calculated according to the design scale of these exchangers. The Langelier Saturation Index (LSI) was used to analyze the scale tendency of the cooling water system. The scale inhibition performance of the inhibitor was verified by static inhibition method. Results show that the scale mainly contains calcium carbonate, and the quality of circulating water is reasonably controlled with a proper range. However, there are three units sharing one cooling water system, of which the flow rate cannot be adjusted according to the actual heat load. The calculation results confirmed that the circulating water velocity in the tube bundle did not exceed 0.9 m/s. Although the scale inhibitor has a scale inhibition efficiency of more than 90% for the simulated circulating water at 80°C, the LSI analysis results showed that the high local temperature on the surface of the tube bundle caused by the low flow rate of water will increase the scaling tendency of the heat exchanger. Furthermore, the untimely injection of the inhibitor in the daily management and operation also greatly increased the risk of system scaling. This paper proves that the scaling of circulating water heat exchanger in the purification plant is mainly caused by device design and poor daily management. In order to prevent future failures, potential solutions and mitigation strategies were put forward.

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Numerical simulation of calcium sulfate (CaSO4) fouling in the plate heat exchanger

Han

et al. 2018

Heat Mass Transfer

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Modeling CaCO3 crystallization fouling on a heat exchanger surface – Definition of fouling layer properties and model parameters

Cited by 59 publications

References 29 publications

Dynamic modelling of Heat Exchanger fouling in multistage flash (MSF) desalination

Dynamic modelling of Heat Exchanger fouling in multistage flash (MSF) desalination

An investigation on scaling failure of heat exchanger in cooling water system of natural gas purification plant

Numerical simulation of calcium sulfate (CaSO4) fouling in the plate heat exchanger

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