Effect of Magnesium Ion Concentration on the Scale Inhibition of Heat Exchanger in Circulating Cooling Water under Alternating Electric Field

This work investigated the effect of magnesium ion concentration on the formation of mineral scale in circulating cooling water under alternating electric field treatment (AEFT) by using a self-made power plant circulating cooling water simulator. In this experiment, the circulating cooling water used was artificial hard water. Three experimental groups with different magnesium ion concentrations and three corresponding control groups were studied. Scale inhibition rate, fouling resistance, calcium ion concentration, crystal phase, and crystal morphology were discussed. Results showed that 4 mmol/L magnesium chloride promoted the formation of scale on the copper tube wall, and the average scale inhibition rate was −107.86%. When the magnesium chloride concentration was 6 mmol/L, the situation was reversed, and the average scale inhibition rate reached 59.11%. The changes in calcium ion concentration supported the scale inhibition rate. Scanning electron microscope (SEM) photos showed the change in the composition of calcium carbonate crystals. The results showed that the effect of AEFT on fouling resistance is nonlinearly related to the concentration of magnesium ions in circulating cooling water.

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Effect of electric field and Mg2+ doping on calcium carbonate scaling shown in experiments and first principle calculations

Water Science & Technology Water Supply ◽

10.2166/ws.2020.215 ◽

2020 ◽

Vol 20 (8) ◽

pp. 3251-3265

Author(s):

Yuping Gao ◽

Judong Zhao ◽

Erjun Zhao ◽

Xiaomin Liu ◽

Yun Jia ◽

...

Keyword(s):

Crystal Structure ◽

Calcium Carbonate ◽

Electric Field ◽

Cooling Water ◽

Ion Concentration ◽

First Principle ◽

Scaling Properties ◽

First Principle Calculations ◽

Scale Inhibition ◽

Circulating Cooling Water

Abstract The effect of an applied electric field and Mg2+ doping on the formation of calcium carbonate scale in circulating cooling water was investigated by using a home-made experimental device, which can simulate the formation of scale in a local power plant. The results show that high-voltage electrostatic fields and magnesium ions can inhibit scale growth in circulating cooling water. When the magnesium ion concentration is 4 mmol/L, the scale inhibition effect is the best under the action of the electric field (6 kV), and its scale inhibition rate can reach 44.56%. Meanwhile, some phenomena are explained and confirmed by the results of first principle calculations. The calculated shear modulus of aragonite is greater than that of calcite. This might explain why aragonite adheres more easily to the heat exchange surface. This is in good agreement with experimental results. Calcite has better anti-scaling properties than aragonite. The crystal structure after physical water treatment is blunt, and the untreated crystal structure is sharp.

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Effect of changes in magnesium ion concentration on cat cerebral arterioles

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1983.245.1.h22 ◽

1983 ◽

Vol 245 (1) ◽

pp. H22-H26 ◽

Cited By ~ 2

Author(s):

J. M. Seelig ◽

E. P. Wei ◽

H. A. Kontos ◽

S. C. Choi ◽

D. P. Becker

Keyword(s):

Cerebrospinal Fluid ◽

Calcium Ion ◽

Ion Concentration ◽

Magnesium Ion ◽

Vasodilator Effect ◽

Pial Arterioles ◽

Cerebral Arterioles ◽

Calcium Ion Concentration ◽

Csf Concentration ◽

Dose Dependent

The effect of changes in cerebrospinal fluid (CSF) concentration of magnesium ion ([Mg2+]) on pial arterioles was investigated in anesthetized cats equipped with acutely implanted cranial windows for the observation of the pial microcirculation. Increased [Mg2+] caused vasodilation, whereas decreased [Mg2+] caused vasoconstriction. The effect of [Mg2+] was dose dependent and was the same in small and larger arterioles. There was an interaction between CSF [Mg2+] and calcium ion concentration ([Ca2+]), such that the vasodilator effect of Mg2+ was greater when the [Ca2+] was lower, especially in larger vessels. The vasodilator effect of Mg2+ on pial arterioles was enhanced in the presence of the calcium antagonist verapamil (0.5 micrograms/ml), despite the fact that verapamil by itself caused a 12-13% arteriolar dilation. These results show that the vasodilator effect of Mg2+ is probably related to an interaction at the cell membrane resulting in reduction in the influx of Ca2+ into vascular smooth muscle.

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Electromagnetic Field Acting on the Scale Inhibition Experiment and Mechanism on Circulating Cooling Water of Power Plant

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.664.62 ◽

2014 ◽

Vol 664 ◽

pp. 62-69

Author(s):

Zhi An Liu ◽

Shan Long ◽

Ju Dong Zhao ◽

Tian Xia ◽

Hui Feng An ◽

...

Keyword(s):

Electromagnetic Field ◽

Power Plant ◽

Cooling Water ◽

Field Size ◽

Inhibition Rate ◽

Crystalline Phases ◽

Inhibition Effect ◽

Scale Inhibition ◽

Circulating Cooling Water ◽

Inhibition Experiment

The scale-inhibition effect of electromagnetic field was tested on circulating cooling water of power plant, and then the scale sample was analyzed by SEM and XRD. The results showed that, under optimum scale-inhibition conditions, aragonite content increased and calcite content decreased, and scale-inhibition rate was up to 78.2%; under the poorest conditions, both aragonite and calcite crystals existed, and the scale-inhibition rate was-201.0%; after treating with electromagnetic field, size of both calcite and aragonite particles decreased, making them more easily flown away and thus showing better overall scale-inhibition effect; when energy provided by the electromagnetic field was more than the decrease in free energy of the system, extra energy turns the calcite CaCO3 into other forms of metastable crystalline phases, then content of different crystalline phases is changed in favor of scale inhibition.

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Synthesis and Properties of Environmentally Friendly Scale and Corrosion Inhibitor

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.618.180 ◽

2014 ◽

Vol 618 ◽

pp. 180-183

Author(s):

Zhen Fa Liu ◽

Xue Bai ◽

Li Hui Zhang ◽

Yan Liang Zhang

Keyword(s):

Weight Loss ◽

High Temperature ◽

Water System ◽

Cooling Water ◽

Inhibition Rate ◽

Polyaspartic Acid ◽

Ternary Composite ◽

Scale Inhibition ◽

Circulating Cooling Water ◽

Good Scale

Polyaspartic acid (PASP) and a copolymer (AA) of acrylic acid and acrylicester were synthesized. A ternary composite (PASP-AA-DTPMP) was made from PASP, AA and DTPMP. The performances of ternary composite were studied by using static scale inhibition and weight loss of rotating hung steel slices test. When the concentration of ternary composite was 6mg/L, the scale inhibition rate reached 95% and the corrosion inhibition rate reached 97.9%. The results showed that the ternary composite had good scale and corrosion inhibiton performance and was suitable for high temperature and hardness circulating cooling water system.

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