Servicing and repair of plate heat exchangers

Servicing and repair of heat exchangers

Servicing of heat exchangers should be performed by specialists with experience and relevant knowledge

Plate heat exchangers are devices designed for heat exchange between two different fluids without them coming into direct contact with each other. They consist of many thin metal plates arranged parallel to each other and pressed together in a frame. Narrow channels are formed between them, through which one of the fluids passes, while heat transfer to the other fluid occurs on the other side. Their compactness, high efficiency, and energy efficiency make such devices indispensable components for heat transfer and cooling. Plate heat exchangers have found a wide range of applications in various industries, including manufacturing, energy, the food industry, and others.

A heat exchanger is a complex device whose components are periodically exposed to various adverse conditions, which can lead to a variety of negative consequences, such as damage and contamination of plates, leaks, wear of seals, corrosion, and even equipment failure. Ultimately, the performance of the heat exchange system can significantly decrease, and a possible breakdown at an inconvenient time can cause serious problems and significant financial losses. Therefore, regular professional maintenance of heat exchange devices is mandatory and important to prevent potential negative consequences.

Reasons for malfunctions

Mechanical impacts, intensive use, and non-compliance with operating rules can lead to premature failure of the device or its components.
Mechanical impacts, chemical corrosion, fouling, thermal stress, improper installation or operation, and wear of seals are among the primary reasons for malfunctions in plate heat exchangers :

1. Aggressive environment. Acids, alkalis, salts, and other chemical compounds lead to damage to the surface of the plates and reduce their efficiency. Over time, wear of the plates can also occur, which can further impair heat exchange. Regular analysis of the composition of the working environment and selection of appropriate materials for the plates can reduce the risk of destruction due to an aggressive environment.
2. Improper maintenance. The absence of regular cleaning and flushing of the plates can lead to the formation of scale and contamination on the surfaces of the heat exchanger. This reduces heat exchange efficiency and can lead to underheating. It is recommended to establish a schedule for regular cleaning and maintenance to maintain the device in optimal condition.
3. Improper installation and assembly. Improper installation of the heat exchanger can lead to stresses in the casing and deformation of the plates, which can cause leaks and reduce productivity. To prevent this, it is necessary to follow the manufacturer’s recommendations and consult experienced specialists for installation and assembly.
4. High temperature loads. Large temperature differences between the mediums involved in heat exchange can lead to deformation and deterioration of the plate material, as well as cause thermal stresses. This can lead to leaks, plate failure, and even destruction of the heat exchanger frame. Regulating temperature regimes and using materials resistant to high temperatures will help reduce the risk of malfunctions.
5. Mechanical damage. Impacts, vibrations, and other influences can lead to damage of the plates and the casing of the heat exchanger. Placing the heat exchanger in safe locations and installing additional safety systems, such as shock absorbers and supports, can reduce the risk of mechanical damage.

Types of repair work

Repair of a heat exchanger is a process of restoring or making modifications to a heat exchange device that is used for transferring heat between two mediums. The repair of a plate heat exchanger includes a set of actions aimed at restoring the functionality and efficiency of the heat exchange system.

Flushing and cleaning heat exchangers is a fundamental aspect of their maintenance

For non-disassemblable (welded, brazed) heat exchangers, only chemical cleaning (flushing) is possible, while for disassemblable ones, both chemical and mechanical cleaning are options. This operation is aimed at removing scale, contaminants, corrosion, and other deposits from the surface of the heat exchangers, which allows for improved heat transfer and overall system performance. The frequency of this procedure is determined individually and depends on factors related to the use of the equipment.

Leak testing and examination are crucial because leaks in heat exchangers can have severe consequences

They can lead to the mixing of different working mediums, leading to potentially hazardous situations. Besides, they cause significant energy and resource losses, affecting costs and the environmental sustainability of processes. The testing procedure for leaks identifies even minor leaks before they lead to serious issues. There are several methods for this:
а) Hydrostatic. It involves filling the heat exchanger with water or another working medium and creating pressure. Then, the system is monitored for any changes in pressure to detect potential leaks.
б) Pneumatic. The heat exchanger is filled with compressed air or an inert gas, and then monitored for pressure changes. Any anomalies indicate the presence of leaks.
в) Dyes or indicators. A special indicator or dye is applied to the surface of the heat exchanger, which changes color or properties upon contact with the working medium.
г) Thermographic testing (thermal imaging control). Special thermal imaging cameras record infrared radiation, allowing the detection of temperature differences on the surface of the heat exchanger, which can indicate a leak. Leak checking and testing of heat exchangers is an important stage in maintaining the efficiency of technical systems. These procedures help to identify and eliminate potential problems at early stages, ensuring the uninterrupted operation of heat exchangers.

Repair and replacement of plates

Plates in heat exchangers are subject to wear over time. This can lead to deteriorated heat exchange, leaks, and reduced system efficiency. Professional assessment, timely repair, or replacement are important measures for maintaining reliable operation of the heat exchanger.
The main steps for repairing plates include:
а) Damage assessment. Experienced specialists conduct a detailed evaluation of the plate damages, including wear, corrosion, and other defects.
б) Cleaning and preparation. Plates are cleaned of contaminants, soot, and deposits. This allows for a more accurate determination of the extent of damage and the need for repair.
в) Restoration of geometry. Plates may become deformed due to mechanical impacts or thermal loads. The repair includes restoring the optimal geometry of the plates.
г) Replacement of seals. If necessary, replacement of sealing elements is carried out to ensure the tightness of the system.
The replacement of plates involves:
а) performance analysis. Before replacing the plates, an analysis of heat exchange efficiency is conducted to determine the necessity of replacement.
б) material selection. The choice of materials for the new plates is made taking into account the chemical properties of the working fluids and operating conditions.
в) installation and testing. The new plates are installed in accordance with strict technical standards. After installation, testing is conducted to ensure their effectiveness.

If you need to perform high-quality maintenance and repair of heat exchangers if you need high-quality maintenance and repair at a low price, contact us. The company “Teplo-Polis” provides repair services for heat exchangers from all manufacturers:

• Funke;
• Alfa Laval;
• Sondex;
• GEA (Kelvion);
• Tranter;
• APV;
• Schmidt;
• SECESPOL;
• and others.

The company “Teplo-Polis” carries out direct supplies from manufacturers of plates and seals. We have been working with plate heat exchangers since 2004. Your heat exchange equipment is in reliable hands.

Preventive maintenance

Heat exchanger involves systematic measures and actions aimed at maintaining proper operation and extending the service life of the heat exchange mechanism. It helps prevent potential problems, reduce the likelihood of failures, and ensure the efficient functioning of the system. Here are some aspects of preventive care for heat exchange units:

• Cleaning and lubrication. Periodically clean the surfaces of the heat exchanger from scale, dirt, and other contaminants, and also monitor the condition of the seals and lubricate them when necessary.
• Inspection. Conduct regular visual inspections of the heat exchanger. Early detection of problems can help prevent their deterioration.
• Replacement of seals and components. If necessary, replace worn seals, tubes, plates, and other components, as this prevents leaks and increases heat exchange efficiency.
• Parameter monitoring. Monitor the operating parameters of the heat exchanger, such as pressure, temperature, and flow rate of the medium, to detect any anomalies.
• Water cleaning and chemical treatment. In systems where water is used, regularly maintain the system and apply chemical treatment to prevent scale formation and corrosion.
• Testing and analysis: Periodically conduct tests and analyses of the heat exchanger’s efficiency. This may include measuring heat exchange efficiency, energy consumption, and other indicators.

The frequency of preventive maintenance depends on the operating conditions and the type of heat exchanger, which is recommended to be carried out at least once a year to not only extend the service life but also reduce costs for repairs and replacements.

Increasing efficiency and extending service life

Improving efficiency and extending the service life of a heat exchanger requires a combination of proper preventive maintenance, optimization of operational parameters, and the application of advanced technologies. Here are several steps that can be taken:

• Regular servicing of heat exchangers will help maintain heat transfer efficiency and prevent equipment damage.
• Utilize chemical treatments to prevent scale formation and corrosion in the heat exchanger.
• Parameter optimization. Monitor the flow rate of the medium, pressure, temperature, etc. Optimizing these parameters can enhance the efficiency of the device.
• Utilize high-efficiency heat transfer fluids.
• Installation of regulators and automation systems can optimize the operation of the heat exchanger based on current conditions.
• Monitoring and diagnostics allow tracking the condition of the heat exchanger and promptly reacting to any anomalies.
• Systematic employee training.
• Upgrading equipment to more modern and efficient models.
• Insulation and thermal insulation to minimize heat losses.
• Utilization of alternative energy sources.

Combining these approaches will not only increase the efficiency of the heat exchanger but also extend its service life, ultimately leading to energy and resource savings.

“Teplo-Polis Services”

We provide a full range of heat exchanger repair and maintenance services:

1. Diagnosis of the operability of a plate heat exchanger and detection of its malfunctions.
2. Disassembly and assembly of a plate heat exchanger.
3. Replacement of plates and seals in a plate heat exchanger.
4. Plate inspection.
5. Chemical non-dismantling cleaning (flushing) of the plate heat exchanger using specially selected reagents.
6. Mechanical cleaning of the heat exchanger.
7. Sandblasting and painting of plates.
8. Manufacturing and replacement of heat exchanger guides, stands, and tie rods.
9. Hydraulic testing of the heat exchanger.
10. Issuing recommendations for further maintenance of plate heat exchangers.
11. Modernization of the heat exchanger aiming at increasing performance and reducing pressure losses.

If you require high-quality technical servicing and repair of heat exchangers at an affordable cost, turn to us.

Why choose Teplo-Polis

The company “Teplo-Polis” carries out direct supplies from manufacturers of plates and seals. We have been working with plate heat exchangers since 2004. Advantages that help us succeed in the market:

• quality (we only use European components in the production of heat exchangers), which affects the durability and reliability of equipment operation;
• quick and optimal solution to difficult engineering tasks related to heat exchange (standard tasks – within a day, complex tasks – up to a week);
• individual approach to each customer;
• reasonable equipment cost.