Titanium anode for electrochemical scale removal
Titanium anode: a new process in the field of electrochemical descaling
Bringing breakthrough progress to the problem of scale in industrial circulating water systems
Circulating water scale removal technology
In the industrial production process, the problem of scale in circulating water systems has always been a key factor affecting production efficiency and equipment lifespan. Traditional descaling methods have issues such as high costs, environmental pollution, or limited effectiveness. However, the emergence of titanium anode electrochemical descaling technology has provided new ideas and methods for solving this problem.
This innovative technology utilizes the principle of electrolysis and, through specially designed titanium anode components, efficiently removes and prevents scale formation without the use of chemical agents. It also has multiple advantages such as environmental friendliness, cost-effectiveness, and long-term effectiveness, and is becoming a new trend in the field of industrial water treatment.
The titanium anode electrochemical descaling technology achieves multiple goals of efficient descaling, equipment protection, energy conservation, emission reduction, and environmental protection through an innovative electrochemical process, bringing significant economic and environmental benefits to industrial enterprises.
The Dilemma of Traditional Descaling Methods
In industrial circulating water systems, the formation of scale is a long-standing and urgent problem to be solved. Traditional descaling methods mainly include chemical descaling and physical descaling, but both methods have certain limitations.
Chemical descaling
By adding chemical agents to the circulating water, such as scale inhibitors and corrosion inhibitors, the formation of scale by scale-forming ions can be prevented.
- The cost of chemical agents is high.
- Cause environmental pollution, which may lead to eutrophication of water bodies.
- Long term use may cause equipment corrosion.
- Increase the maintenance costs of enterprises.
Physical descaling
Descaling is achieved by means of mechanical external forces or the action of physical fields. Common methods include mechanical descaling, ultrasonic descaling, etc.
- Cannot completely remove limescale in small gaps and complex structures.
- It is easy to damage the surface of the equipment.
- Limited scope of action, and energy is prone to attenuation.
- High cost of cleaning and decontamination.
Principle of Electrochemical Descaling Technology
Electrochemical descaling technology, as an emerging method for removing scale, offers a new approach to solving the problem of scale accumulation in industrial circulating water systems. The basic principle of this technology is based on electrolytic reactions. By installing an anode and a cathode in the water and applying a direct current electric field, the water molecules and the ions in the water undergo a series of complex electrochemical reactions under the influence of the electric field.
The core function of titanium anode
In the electrochemical descaling system, titanium anodes have become a key component due to their excellent performance. When a direct current electric field is applied to the circulating water containing dissolved salts, the following reactions occur on the electrode surface:
At the anode (titanium electrode), an oxygen evolution reaction occurs:
2H2O→O2↑ + 4H+ + 4e–
At the cathode, a hydrogen evolution reaction occurs:
2H2O + 2e– → H2↑ + 2OH–
Descaling process
Under the influence of an electric field, ions in water undergo directed migration:
- Cations such as Ca2+ and Mg2+ migrate towards the cathode, and in an alkaline environment, they form loose precipitates of Ca(OH)2 and Mg(OH)2.
- Anions (such as CO32-, SO42-, etc.) migrate to the anode.
- In an acidic anodic environment, the already formed calcium carbonate scale can be dissolved: CaCO3 + 2H+ → Ca2+ + CO2↑ + H2O.
- The reactive oxygen species generated at the anode attack the lattice structure of the scale layer, reducing the adhesion of the scale.
Electric fields have a significant impact on the behavior of ions in water. Scale forming cations in water, such as Ca²⁺ and Mg²⁺, migrate toward the cathode under the influence of the electric field force; while anions like CO₃²⁻ and SO₄²⁻ migrate toward the anode. This directional migration alters the distribution of scale forming ions in water and disrupts the concentration balance of these ions in local regions. In the cathode area, due to the increased concentration of OH⁻, an alkaline environment is formed, where cations such as Ca²⁺ and Mg²⁺ combine with OH⁻ to generate precipitates like Ca(OH)₂ and Mg(OH)₂. These precipitates exist in the form of loose flocs, which are not easy to adhere to the surface of equipment to form hard scale. Instead, they can be discharged from the system through water flow scouring or regular sewage discharge operations. In the anode region, due to the increased concentration of H⁺, an acidic environment is created. On one hand, it can dissolve part of the already formed scale such as calcium carbonate, with the reaction formula being CaCO₃ + 2H⁺→Ca²⁺ + CO₂↑ + H₂O; on the other hand, the reactive oxygen species generated at the anode (such as hydroxyl radicals ・OH, O₃, etc.) have strong oxidizing properties, which can attack the lattice structure of the scale layer, causing lattice distortion of the scale crystals, transforming from a dense calcite structure to a loose aragonite structure, reducing the adhesion of the scale and making it easier to be carried away by water flow.
Innovative Applications of Titanium Anodes
Electrochemical descaling titanium anodes exhibit extensive applicability and excellent performance. In addition to industrial circulating water systems, they also play an important role in multiple fields, providing effective solutions to scaling problems in different industries.
A petrochemical enterprise used to adopt chemical descaling methods for its circulating water system. It had to spend a large amount of money on chemicals every year, and the equipment was severely corroded, resulting in high maintenance costs.
After adopting electrochemical descaling technology and equipping with titanium anodes, the system achieved remarkable results after one year of operation:
Central air conditioning system
Electrochemical descaling devices using titanium anodes can effectively prevent scaling on components such as condensers and evaporators, ensure the cooling and heating efficiency of the system, extend the service life of equipment, and reduce the number of maintenance operations and costs.
Cooling tower system
Not only does it solve the problem of water scale, but the active substances such as hypochlorous acid produced by the titanium anodes also have antibacterial and disinfecting properties. They inhibit the growth of microorganisms, reduce the formation of biofilm, and help to keep the cooling tower clean and in proper operation.
Boiler system
Electrochemical descaling titanium anodes can efficiently remove scale without damaging equipment, reduce energy consumption, improve the thermal efficiency and safety of boilers, and lower the risk of failures caused by scaling.
Other industrial systems
These systems are widely used in various cooling systems and heat exchange equipment in industries such as metallurgy, power, and chemicals. They effectively address the issue of water scale under different operating conditions, thereby improving production efficiency.
Although electrochemical descaling titanium anodes have demonstrated significant advantages in industrial applications, they still face several challenges that need to be overcome in order to further enhance their performance and expand their range of uses.
The challenge of treating water with high hardness
In high hardness water bodies, when the concentrations of calcium and magnesium ions in the water are too high (for example, when the total hardness exceeds 800 mg/L), a large amount of Ca(OH)₂ and Mg(OH)₂ flocs are generated in the cathode area. If these flocs cannot be promptly carried away by the water flow, they tend to accumulate on the cathode surface or in the water flow channels, causing blockages and affecting the normal operation of the system. For instance, in some areas where groundwater has extremely high hardness, after using electrochemical descaling equipment, problems with poor water flow in the cathode area occur within a short period, requiring frequent shutdowns for cleaning.
The cost of precious metal coatings is relatively high
The high cost of the precious metal coatings on the surface of titanium anodes is one of the key factors limiting their widespread use. Taking the common RuO₂ IrO₂ coating as an example, the prices of precious metals such as ruthenium (Ru) and iridium (Ir) are quite high. This poses a significant initial investment challenge for companies with limited budgets or for large scale water treatment projects. Additionally, the current manufacturing processes for these coatings are relatively complex, which further restricts their application in large industrial water treatment systems.
Maintenance issues in complex water quality conditions
In an environment enriched with organic pollutants, substances such as oils, greases, and colloids in water can cover the active sites of the MMO coating, hindering the progress of electrochemical reactions. This necessitates regular acid cleaning maintenance of the anode to restore its activity. Compared with traditional processes, under such complex water quality conditions, the frequency of acid cleaning maintenance may increase by 50%, which not only increases maintenance costs but also may cause certain corrosion damage to the equipment.
