The heating boiler, like almost any technological equipment operating in difficult conditions, needs periodic maintenance. One of the most important operations carried out during the maintenance of a gas boiler is the cleaning of its heat exchanger.

heat exchanger is a metal (or cast iron) box with a built-in radiator, which is heated from the outside by a burner flame and transfers heat to the liquid flowing inside. If the heat exchanger is clean, then it works with maximum efficiency, giving almost all the energy received for heating. However, over time, various impurities begin to precipitate on the walls of the internal channels, which are compounds of salts dissolved in the coolant (scale). The formation of lime deposits is especially intensive in the secondary heat exchanger of a double-circuit boiler, if hard water is used in the DHW line.

Such contamination of the heat exchanger channels can lead to a number of unpleasant consequences:

• Reduced boiler efficiency. Mineral deposits have a much lower thermal conductivity than metal, so much more energy will have to be spent on heating water. Accordingly, the gas consumption will also increase.
• Heat exchanger overheating. The scheme of operation of gas boilers assumes that the coolant coming from the return line cools the internal cavities of the heating element. When scale appears, the cooling efficiency drops, the heat exchanger overheats and quickly fails.
• Breakdown of heating equipment. Mineral deposits on the inner walls of the heat exchangers make it difficult for the coolant to pass through them. This creates an additional load on the circulation pump, which will quickly exhaust its resource if the narrowed channels are not cleaned in time.

Thus, timely flushing of the heat exchanger will help save significant funds by preventing the breakdown of expensive components and ensuring the minimum required fuel consumption.

Frequency of cleaning the heat exchanger

In different sources, you can find rather conflicting information about how often cleaning of various elements of heating boilers should be carried out. As a rule, maintenance intervals are given in the instructions for a specific model. However, please note that these figures are approximate and are based on the most favorable operating conditions. In fact, flushing of heat exchangers may be required more frequently.

It is possible to assess how heavily the heat exchanger is clogged by several indirect signs that accompany the operation of a gas boiler:

The design of modern boilers is designed for long-term use, and the cost of spare parts for them is quite high. Therefore, the heat exchanger should be cleaned immediately when the symptoms described above appear. Otherwise, the cost of maintaining heating boilers can increase significantly.

Methods for cleaning heat exchangers

Flushing of the heat exchanger can be carried out in different ways. Next, we will consider them in more detail, and at the same time we will note how to clean the heat exchanger of a double-circuit boiler, which is especially prone to the formation of organic deposits.

Manual cleaning

To solve the problem in this way, the heat exchanger must be completely removed from the boiler in order to gain free access to it. After that, it can be cleaned with various tools:

• mechanical cleaning. You can remove plaque from the inner surface with a hard metal brush or a special scraper;
• flushingin special formulations. Most often, heat exchanger parts are soaked in an acid wash solution. This method is especially effective for removing stubborn dirt, for example, in the channels of double-circuit gas boilers.

The manual cleaning method is simple and effective. It can be used to flush the heat exchanger yourself. The only remark is that it is necessary to be careful when working with the sealing elements of the boilers and monitor the tightness of all connections.

Hydrodynamic cleaning

Flushing of heat exchangers of a gas boiler can be carried out without disassembling it.

Hydrodynamic cleaning is a process of mechanical removal of scale from the walls of pipelines using high-pressure water jets, which sometimes contain impurities of small abrasive particles.

Such a procedure is carried out with the help of special installations that pump pressure up to one and a half thousand bar in the line. This is the most effective, although quite expensive, way to clean heat exchangers.

Chemical cleaning

Chemical flushing of the elements of gas boilers consists in the fact that an acid flushing solution is introduced into the system using a special device called a booster. Then this solution is run through the heat exchanger for several hours and cleans it. This method allows you to remove the most difficult types of deposits - carbonate scale and ferric iron.

The disadvantages of chemical cleaning include the high cost of the reagent, metal wear and a large amount of toxic waste.

Fluids for flushing heat exchangers

In conclusion, consider the question of how to flush the heat exchanger of a gas boiler. Despite the abundance of recommendations in various sources, some care must be taken in choosing a cleaning agent.

Many experts recommend using hydrochloric acid for flushing. It removes scale really well, but it is a rather aggressive compound that can break the protective coating of the inner surface of the heat exchanger.

In addition, there is evidence that washing with hydrochloric acid can cause metal brittleness.

Less dangerous for the heat exchanger material is citric acid. It perfectly copes with all types of deposits, as well as special reagents: DETEX, Cillit, Sanaks and others.

Timely and proper care of the elements of the heating system will increase its service life and reduce the cost of maintaining performance. Cleaning the heat exchanger, as one of the most important operations performed in the maintenance of boilers, will make the most significant contribution to this process.

During operation, the heat exchange device becomes dirty, scale forms on the walls and plates, sedimentary material settles, which worsens not only the performance of the equipment, but also disables it. In order not to bring to such an extreme, heat exchangers are cleaned of contamination either with their complete disassembly or without disassembly. There are several ways to clean heat exchange equipment, but the most popular is chemical.

Chemical method

This is a set of measures aimed at flushing the heat exchanger with all kinds of chemical reagents that can destroy and rid the system of scale. The choice of reagent is made based on the characteristics and magnitude of contamination.

The implementation of the method is as follows: a reagent is introduced into the heat exchanger with a special device, it circulates inside for several minutes, and then it is removed from there with washing water. Together with the remaining reagent, the PHE must be free of dissolved scale and contaminated water. If one wash cycle is not enough, then the process is started again, and possibly more than once. In addition, more effective reagents are introduced.

The advantage of chemical washing is that the unit does not need to be disassembled, which saves time and money for the event.

In addition to the composition of the cleaning agent, attention should be paid to the temperature of the washing solution, because it also affects the cleaning efficiency. The heating level of the solution is selected taking into account the type and composition of scale.

An unsuccessful cleaning operation and the aggressive action of the chemicals used can lead to partial destruction of materials and the formation of cracks in plates and gaskets. And the use of liquid cleaning agents, such as hydrochloric acid, increases the degree of damage and reduces the life of the heat exchanger. Therefore, chemical washing should be carried out using certified reagents, entrusting the work to real professionals!

Hydrodynamic method

Flushing is carried out by means of a water jet, through which water is supplied under high pressure through a hose to the internal PHE system. A variety of nozzles on the hose and varying the power of the water jet allow you to rid the heat exchanger of any contamination, including clogged pipes with zero clearance. Under the influence of powerful hydrodynamic pressure, even stubborn deposits are destroyed.

Electrohydropulse method

PHE cleaning is accompanied by water hammer, which occurs when a high-voltage discharge is applied to the liquid. All this is called the Yutkin effect. A running generator replaces the alternating voltage with a direct one. The high voltage obtained at the output is fed in parallel to the capacitor through the arrester. Impulse discharge occurs, which provokes the formation of a shock wave in the system. The efficiency of the flushing process is affected by the following:

• water hammer propagates at different speeds in different types of deposits
• the greatest voltage occurs when a wave passes between the metal surface of the unit and solid deposits on it;
• exfoliated contaminants are washed off with a water hammer and brought out.

Water jet cleaning method

When using this method, a combination of water jet and abrasive cleaning of the PHE occurs. Its advantages:

1. high performance;
2. lack of severe pollution and dust in the workplace.

Description:

State Unitary Enterprise "Teploremontnaladka" has been working in the public utilities sector of Moscow since 1992, specializing in the installation and maintenance of heating points for housing stock, educational and healthcare facilities, and administrative buildings. In 1997, the replacement of shell-and-tube heat exchangers with plate heat exchangers in hot water supply and heating systems began.

Chemical flushing of plate heat exchangers

N. V. Sologubova, chemical engineer, State Unitary Enterprise "Teploremontnaladka"

State Unitary Enterprise "Teploremontnaladka" has been working in the public utilities sector of Moscow since 1992, specializing in the installation and maintenance of heating points for housing stock, educational and healthcare facilities, and administrative buildings. In 1997, the replacement of shell-and-tube heat exchangers with plate heat exchangers in hot water supply and heating systems began.

Two years later, we faced a number of problems. Due to the high corrosivity of the pipeline material, a large number of corrosion products pass into the water, including a huge amount of iron compounds. When water passes through a plate (water) heater in a temperature range of 5–65 ° C, mineral salts contained in water and a significant part of various forms of iron are deposited on the surface of the plates. The resistance of the boilers began to grow rapidly, the temperature of the hot water at the outlet of the boiler fell, the heat removal decreased and the return temperature of the coolant increased.

Opening the boilers and examining the surface of the plates showed a high degree of their contamination - a layer of rust-salt deposits reached 1–3 mm, the grooves on the plates were completely clogged. The resulting deposits, despite the apparent friability, have a very high adhesion, i.e., adhesion to the surface of the plates, which may be due to the presence of a copper chloride film, which has a porous structure and enhances adhesion. The film thickness is about 30 microns and it is extremely strong.

Practice has shown that mechanical cleaning of the plates manually is ineffective and very time consuming. It is necessary to involve only qualified workers in such work. For example, manual cleaning of M10 heat exchangers takes 1 shift with a team of 4 people. In this case, there is a high probability of damage to the gaskets between the plates. Only the deposit of deposits is removed from the plates, the film with a thin surface layer of contamination remains intact. The plates become dirty again within 6 months. The search for ways to clean the plates showed that chemical cleaning is the most effective. There was a need to create a chemical solution for washing the plates of water heaters.

In January 2000, State Unitary Enterprise "Teploremontnaladka" together with OOO "Hemalyuks" began work on the development of cleaning technology and the selection of cleaning compounds.

Type heat exchanger pressure loss, m. Stolba Time, min Tempe- ratura Concentrated tradition Before flushing After flushing Estimated M3 GVS-1st 2 0,1 1,28 50 40 3% M3 GVS-2st 4 2 2,76 40 40 3% M10 GVS-1st 3 1 0,983 50 37 5% M6 GVS-2st 5 1 2,36 50 37 5% M15 DHW 1 st. 2 0,5 0,993 60 35 5% M10 DHW-2st. 4 0,8 2,74 60 35 5% M10 is heated. 4 0,5 1,89 30 30 4% М3* DHW 1 tbsp. 5 0,6 1,27 60 40 3–4–5% М3* DHW 2 st. 7 2 2,76 60 40 3–4–5%

It was decided to take an inorganic acid as the basis of such a solution. In laboratory conditions, solutions of hydrochloric, sulfuric and orthophosphoric acids were worked out on dirty plates. Hydrochloric acid must not be used on carbon steel materials. Sulfuric acid affected the material of the seal and itself at a temperature of 35–40°C is corrosive to the material of the plates. Orthophosphoric acid is able to passivate (i.e., create a protective active film) the surface of the plates and does not affect the seal, but even its 30% solution removed impurities only partially and did not provide the required degree of cleaning of the plates. In addition, the solution was quickly worked out (depleted), which required the addition of new portions of the fresh composition. The search for the optimal cleaning agent led to the preparation of a solution of a complex composition, including organic acids, orthophosphoric acid became the basis of the composition.

The solution has a number of fundamental advantages compared to others and meets the requirements:

Provides fast and complete removal of rust-salt deposits, including film removal by 70–80%;

Provides cleaning at low temperature of the working solution (20–35°С) and its low concentration (3–5%);

Does not change the properties of the sealing material;

Partially passivates the surface of the plates, slowing down the re-formation of the film.

The main distinguishing feature of this composition from others is the descaling mechanism, which provides the above advantages and benefits. The composition provides priority exfoliation of pollution with its subsequent dissolution.

The technology of flushing water heaters was tested, which includes two stages.

1st stage:

A closed loop is created, where the working solution is pumped through the heat exchanger by a pump.

2nd stage:

To neutralize the acidic component of the cleanser, a neutralizer (drinking or soda ash) is added 10–15 minutes before the end of washing, bringing the pH of the solution to 8.5–9.

After washing is completed, the working solution is diluted with tap water to the norms acceptable for draining, preparing for discharge into the sewer. Solid sediments are disposed of as household waste.

In May-June 2000, the flushing technology was tested in practice. Heat exchangers of different types were chosen as experimental ones - from small (M3 type) to the largest (M15 type). The overall results are presented in the table.

Both heating and hot water boilers were pressure tested at 10 atmospheres after flushing. No deviations were found in their work. It should also be noted that when washing the brazed heat exchanger with a composition with a concentration of 5%, copper leaching was not observed.

"Warm Company" offers comprehensive maintenance, cleaning and repair of heat exchange equipment in Moscow and St. Petersburg. Our services include the following types of work:

• Flushing of plate heat exchangers(physical, chemical)
• Repair of heat exchangers
• (physical, chemical)
• (physical, chemical)
• Maintenance of heat exchangers
• replacement of seals
• power increase, installation
• supply of spare parts
• consultations

Maintenance of plate heat exchangers: why in Moscow or St. Petersburg is it worth contacting the "Warm Company"?

Our services include washing of plate heat exchangers and their maintenance of the following manufacturers: Alfa Laval, Swep, Gea Ecoflex, G-Mar, Funke, EESTI Termotehnika, MASHIMPEKS, Promenergo, Etra, Thermoblock software .

When cleaning, repairing equipment and pipelines, we use only original spare parts, high-quality equipment (for example, pumps), and specially designed reagents. The service of washing the heat exchanger with acid is in great demand.

By contacting us, you will receive the highest level of service, your equipment will work for a long time and uninterruptedly. This means you save a lot of money!

Cleaning of heat exchangers, flushing of heat exchangers - the choice of method!

Cleaning in place of heat exchangers is selected as the main cleaning method in the following cases:

• when it is necessary to flush the heat exchanger, both brazed and semi-welded;
• when the degree of fouling is assessed as low or medium (method of washing the heat exchangers with acid).

collapsible the most effective and is used in the event that the degree of contamination of the heat exchangers is assessed as severe. This may be due to the fact that the channels are completely clogged with deposits and the heat exchangers need to be cleaned. In such cases, manufacturers advise resorting to a collapsible method that is guaranteed to remove any contamination.

Scheduled preventive maintenance is less painful, significantly extending their lifespan. At the same time, performance improves as well. The main signs of the need for maintenance are: an increase in pressure losses, failure to provide a temperature schedule in relation to the passport values. Conclusion of technical specialists - it is necessary to clean the heat exchanger.

A timely and regular procedure for washing the heat exchanger plates - this is the removal of deposits, scale, dirt, microorganisms of devices of any type significantly extends the service life, which is much cheaper than its overhaul. Nothing is more costly than unscheduled production shutdowns.

However, these costs can be avoided, as much can be planned before the problem becomes a reality. It is only necessary to outline a plan of preventive measures in advance. For example, seals are subject to wear. However, if they are replaced in time, leaks leading to various costs can be avoided. Plates may become dirty. Scale has a negative effect on heat transfer and impairs the quality of work. In some cases, an increased pressure drop can cause serious problems. Timely cleaning and flushing will help to avoid such problems.

Cleaning and flushing of the plate heat exchanger. Service of washing of heat exchangers.

In the process of work, our company uses special chemistry that does not lead to the destruction of the surface of the plates, does not react with seal materials, and at the same time effectively removes almost any type of deposits and scale that form as a result of operation.

Works on the chemical washing of plate heat exchangers, performed by our company, are characterized by high quality, corresponding to international standards, reliability, optimal price-quality ratio.

As part of the service, we clean and wash the heat exchanger plates with chemicals, including acid.

Maintenance and overhaul of heat exchangers

Current repair of the heat exchanger is the prompt elimination of defects in heat exchange equipment. The need for such an event as repair of a heat exchanger may arise in such situations as:

• leakage at one or more places between the plates;
• flow of media from circuit to circuit.

Overhaul of the heat exchanger - is a set of the following activities:

• replacement of all seals after the expiration of their service life (4-6 years);
• complete cleaning of heat exchangers from deposits, scale;
• inspection of the plates for signs of corrosion, rejection of such plates.

Our company provides round-the-clock service for any heat exchangers (emergency service for cleaning and washing the plates in the heat exchanger), as well as an emergency repair service for heat exchangers of any complexity. We also carry out work to maintain the constant performance of your equipment.

You can enter into a service contract or arrange individual visits. The important thing is that you can manage the situation without allowing problems to arise.

We always have the main components and spare parts for the types of heating equipment we service.

As you can see from the photo, timely maintenance is an IMPORTANT condition for stable operation. Seals and some plates have failed

The specialists of the Warm Company clean the plates in an acid bath and wash the plates under pressure.

The cost of flushing heat exchangers, cleaning and repair of plate heat exchangers - Base prices in Moscow and St. Petersburg.

This table shows several types of heat exchangers. You can find out all the prices for the relevant works on the page with prices of our website. The price does not include spare parts. The indicated prices are indicative.

Ridan (Ridan), Sondex (Sondex)

	10	20	30	40	50
HH-S04	RUB 11,212.00	RUB 11,424.00	RUB 11,636.00	RUB 11,848.00	RUB 12,060.00
HH-S07	RUB 11,611.20	RUB 12,022.40	RUB 12,433.60	RUB 12,844.80	RUB 13,256.00

Etra (Etra) Funke (Funke)

	heat exchanger
	10	20	30	40	50
ET-004/FP04	RUB 11,212.00	RUB 11,424.00	RUB 11,636.00	RUB 11,848.00	RUB 12,060.00
ET-005/FP-08	RUB 11,611.20	RUB 12,022.40	RUB 12,433.60	RUB 12,844.80	RUB 13,256.00

Tranter, Swep

	Number of plates in the heat exchanger apparatus
	10	20	30	40	50
GX06-07-08	RUB 11,611.20	RUB 12,022.40	RUB 12,433.60	RUB 12,844.80	RUB 13,256.00
GC-09	RUB 11,611.20	RUB 12,022.40	RUB 12,433.60	RUB 12,844.80	RUB 13,256.00

Teplotex APV

	10	20	30	40	50
U165, TR 1	RUB 11,212.00	RUB 11,424.00	RUB 11,636.00	RUB 11,848.00	RUB 12,060.00
SR-2	RUB 12,212.40	RUB 12,924.80	RUB 13,637.20	RUB 14,349.60	RUB 15,062.00

Mashimpex GEA

	Number of plates in the machine
	10	20	30	40	50
VT-04	RUB 11,212.00	RUB 11,424.00	RUB 11,636.00	RUB 11,848.00	RUB 12,060.00
VT-10	RUB 12,212.40	RUB 12,924.80	RUB 13,637.20	RUB 14,349.60	RUB 15,062.00

Alfa Laval

	Number of plates in the machine
	10	20	30	40	50
M6	RUB 12,212.40	RUB 12,924.80	RUB 13,637.20	RUB 14,349.60	RUB 15,062.00
M10	RUB 16,710.00	RUB 17,920.00	RUB 19,130.00	RUB 20,340.00	RUB 21,550.00

A heat exchanger is a device through which the heat generated by the coolant is transferred to the environment. Inside the device there are corrugated plates through which the liquid (coolant) passes. Heating equipment, a plate heat exchanger (PHE) (Figure 1), is considered one of the most reliable devices, but with its own drawbacks.

Washing the plate heat exchanger is one of the mandatory procedures that is necessary for the successful operation of the device, to prevent repairs in the future. Due to the fact that the liquid heat carrier has substances in its chemical composition that are capable of settling on the plates, cleaning the device from blockages is necessary. Carrying out the procedure is the key to successful and efficient heat transfer.

Rice. one

PHE and the need for regular cleaning

Since PHE is an efficient and cost-effective heating equipment, it is widely used by modern enterprises. Not a big investment in the operation of the equipment, high efficiency from use is carried out precisely due to the flushing of plate heat exchangers. Other types of heat exchangers require more frequent cleaning than PHEs.

Lack of flushing of plate heat exchangers is fraught with the following consequences:

• Loss of efficiency in the operation of equipment;
• The pollutant changes the thermal conductivity of the plates;
• The likelihood of an accident increases.

The plates are made of thin metals, which allows you to achieve maximum thermal efficiency. Lack of cleaning, in turn, this figure underestimates precipitation, and the lack of cleaning leads to equipment repair work. Not flushing the plate heat exchangers reduces the efficiency of the device, and the cost of maintaining the desired heat increases. Flushing (cleaning) is necessary to remove accumulated dirt that adversely affects the performance of PHE tasks.

Rice. 2

Also, if the device is not cleaned (washed) in time, it will eventually result in an emergency situation, the elimination of which will require financial costs, repairs by specialists. Timely flushing of plate heat exchangers helps to maintain the efficiency of system work at a high level, saves money that will not be spent on repairing plate heat exchangers.

Flushing the heat exchanger and PHE

A heat exchanger of any kind will last a long time, will not require repair if it is flushed (cleaned) in a timely manner. There is a comprehensive range of flushing implementation. Cleaning of contamination that interferes with the normal functioning of the equipment is carried out. Most of the heat exchangers need to be flushed from settling on the walls of the components of the heat carrier.

To prevent repair of plate heat exchangers and most others, regular cleaning is important. It is imperative that the PHE be cleaned once every two or four years, but possibly more frequently. If you do not adhere to such a system, then the repair of plate heat exchangers, and in the future the replacement of the heat exchanger with a new device, will turn out to be a familiar activity. Repair costs will not be cheap, unlike preventive flushing (cleaning).

The most dangerous for the operation of the PHE is scale, which settles on the inside of the heat exchanger. Scale is called deposited hard salts, magnesium hydroxide. Cleaning of aggressive substances occurs by flushing the heat exchanger with a chemical type. But the scale can also have a more complex composition, which can only be cleaned using a mechanical flushing (cleaning) of the heat exchanger.

Cleaning of plate heat exchangers is possible using:

• Chemical washing;
• mechanical flushing.

The choice of PHE flushing method depends on the following factors:

• type of scale;
• constituent substances in the coolant;
• stages of heat exchanger fouling.

Chemical flush

Cleaning the plate heat exchanger with a chemical flush (fig. 2) is used only in case of low fouling of the PHE. For seriously contaminated equipment, cleaning should only be done mechanically.

Rice. 3

Chemical reagents destroy and remove less aggressive scale from the PHE. When purchasing a flushing agent (cleaning), you need to familiarize yourself with its composition, choose the best option that would correspond to the composition of the coolant.

The equipment is not dismantled before cleaning the plate heat exchanger. This is the difference between dry cleaning and mechanical cleaning, and savings. Special equipment is used to introduce chemicals into the PHE unit, as well as remove dirty water with peeled off scale.

Stages of dry cleaning:

• Special equipment introduces a chemical solution with active reagents into the PHE. Substances destroy scale.
• Chemicals for some time (according to the instructions of the product) are and circulate inside the PHE. During this time, deposits are destroyed.
• Flushing (cleaning) of the PTO is carried out with clean water. Water, like a chemical agent, circulates inside the equipment for some time. Then the liquid is removed.
• The above three points are repeated until the outlet water is visibly clean.

After cleaning the PHE, it is important to check the equipment. The device must be tested for normal operation:

• Measure the coolant pressure in the PHE;
• Check the possibility of leakage, the integrity of the device.

In order to avoid repair of the PTO, its failure, a check before starting should be mandatory.

Mechanical flush

Mechanical cleaning is also called collapsible (Figure 3). This cleaning method is used less frequently, as it copes with severe pollution, small corrosive deposits, which are rarely allowed by the owners. This method of cleaning takes more time, requires disassembly of the plates, and is less expensive than repair. The plates are washed under strong water pressure. A large amount of deposits that have been formed for a long time can be cleaned due to hydrodynamic flushing (cleaning).

Rice. 4

The main advantage of using cleaning under strong water pressure:

• Environmental friendliness. There is no use of a chemical reagent that pollutes the environment and poisons the air.
• Simple descent of waste water. In the case of dry cleaning, it is necessary to remove water, clean the device from chemical residues several times.

The disadvantage of mechanical cleaning can be attributed not only to the disassembly of the device, but also the use of special equipment to create water pressure. This method is used only for PTO. In the case of brazed heat exchangers (Fig. 4), their flushing (cleaning) is possible only with the help of chemicals. If the amount of deposits is too large, chemical agents are powerless, then the brazed plates must be partially replaced. If they cannot be repaired, then a complete replacement is required.

Rice. 5

After cleaning the device, it is important to properly assemble the structure. The next stage of activities after the completion of the flush, as in the case of dry cleaning, is equipment testing. A number of tests will help to establish whether the device is ready for operation, whether it can be repaired, etc. If leaks or other problems are found, then it is necessary to disassemble the device again, and then reassemble it.

Comprehensive cleaning measures

Cleaning a plate heat exchanger using a chemical and mechanical method is quite effective, but sometimes complex cleaning is also required. A large layer of corrosion is removed in a complex way: the device is disassembled, cleaned using chemicals and strong water pressure.

This method is the most expensive, after the failure to clean, only repairs will be required. After disassembling the plates, cleaning is carried out with chemicals, water pressure, cleaning from aggressive reagents and proper assembly of equipment with testing for proper functioning.

To avoid repairs, it is necessary to carry out preventive actions that will help save money and time.

The VekFort company implements the whole range of works on cleaning heat exchangers using high-quality innovative materials and effective methods to combat unwanted deposits. Thanks to their use, our specialists can guarantee high quality cleaning and greater efficiency of the work carried out. Masters of VekFort have extensive experience in project planning and management, especially when the completion date is one of the main criteria.

The main advantages of working with VekFort:

• To achieve the optimal cleaning result for heat exchangers, boilers, and other heat and heat exchange equipment, hydrochemical and hydrodynamic, hydropower and hydroabrasive cleaning technologies are used, which are currently the most effective.
• During the work, high-quality powerful equipment is used, including hydrodynamic machines with a pressure of up to 1500 bar, installations for cleaning the internal surfaces of pipes using soft abrasive materials, hydraulic impulse equipment for cleaning pipes with diameters from 10 to 100 mm, as well as pumping stations with a capacity of up to 200 m3 / h to ensure the circulation of reagents.
• The company has implemented a quality management system ISO 9001-2008, which guarantees the accuracy of all business processes.
• The company has implemented the environmental management system ISO 14001:2004.
• The company has implemented the occupational safety and health management system OHAS 18001:2007
• For the most effective cleaning by the hydrochemical method, reagents and corrosion inhibitors are used, which have the highest efficiency.
• The company is a design organization and has a SRO permit for the design of works that affect the safety of capital construction facilities; for each type of work, a project for the production of works or technological regulations is developed
• Professional specialists have all the necessary certificates and carry out work strictly according to technological maps.
• The VekFort company is responsible for the structural materials of boiler equipment and excludes their damage.
• The company employs qualified inspectors, whose duty is to conduct internal control of the work performed before handing it over to the customer.

Heat exchangers are actively used in the metallurgical, chemical, oil, gas and municipal industries. VekFort offers its customers the following services for all types of industrial heat exchangers:

• cleaning of shell-and-tube heat exchangers;
• cleaning elemental (sectional) heat exchangers;
• cleaning of twisted heat exchangers;
• cleaning of two-pipe heat exchangers;
• cleaning of plate heat exchangers;
• cleaning of finned heat exchangers.

There are several types of standard technologies for cleaning heat exchangers. The choice of a particular one can be influenced by the type of heat exchanger design, the characteristics of the cleaning apparatus and the degree of contamination. The VekFort company offers a variety of methods for cleaning heat exchangers using various technologies, including innovative ones. All of them correspond to the Russian categories of standards GOST, SNiP 3. 05. 05-84, as well as the norms of ISO, the International Organization for Standardization.

Hydrochemical cleaning of heat exchangers

Hydrochemical treatment of heat exchange devices is very effective in combating unwanted deposits, scale. The increase in the number of layers leads to the fact that industrial and utility systems operate at a low level of efficiency. This leads to a decrease in fluid temperature, excessive fuel consumption and an increase in the number of unplanned repairs. Hydrochemical cleaning involves cleaning without preliminary analysis of the structure itself. Cleaning is carried out due to the interaction of chemical reagents circulating in a closed circuit with scale-corrosion deposits on the inner surfaces of plates, pipes and other elements of the heat exchanger.

Clogging of the inner surface of the pipeline of heating systems, which have a service life of more than 10 years, is 60%, and pipes in buildings over 15 years 80%. As a result of deposits, the temperature in the premises decreases, and transportation costs increase.

For hydrochemical cleaning, VekFort uses special installations, which consist of pumps, tanks for preparing the solution, hoses and filters. The pumps used by us allow pumping up to 500 m3/hour. For this washing method, I use reagents based on organic or inorganic acids with the obligatory presence of corrosion inhibitors. They are certified by the Sanitary and Epidemiological Supervision of the Russian Federation and do not destroy the integrity of heat exchangers and other equipment. Such chemicals are able to eliminate scale and corrosion, and also destroy all biomass: mold, fungi, algae, microorganisms. Only hydrochemical cleaning of heat exchangers makes it possible to get rid of biological organisms in full.

Hydrochemical cleaning of heat exchange devices will provide:

• restoration of the original throughput; increase in service life of heat exchangers of other equipment by 10-15 years;
• reduction of heat loss during transportation by 20-30%;
• increasing the temperature of a liquid, steam or gas to the required values ​​without increasing fuel consumption;
• 50% reduction in fuel consumption.

Hydrochemical cleaning is a good alternative to overhaul, as its cost is several times lower than the replacement of the heat exchange equipment itself. The undoubted advantage of hydrochemical cleaning is the speed of work performed. The entire washing complex is carried out in one cycle.

There are several types of hydrochemical cleaning:

• collapsible hydrochemical cleaning;
• in-place hydrochemical cleaning of plate heat exchangers;
• hydrochemical cleaning of shell-and-tube heat exchangers.

Hydrodynamic cleaning of heat exchangers

The essence of this method of washing the heat exchanger is that the contaminated surfaces are treated with running water under pressure up to 1500 bar. As a result of this, all kinds of deposits and scale are washed off. In most cases, this cleaning method involves the dismantling of heat exchange devices, however, for tubular heat exchange devices, this measure is not necessary. This method involves the use of special installations, which are distributors of a water jet under high pressure. In the presence of significant deposits and dried scale, coarse sand is sometimes used. For greater efficiency, VekFort specialists use nozzles of various modifications that allow you to adjust the required pressure and the angle of its distribution of the jet. They can also use narrow nozzles with a large number of holes that allow you to get inside any device.

Today, this method of cleaning is considered the most effective. It has a number of advantages over others:

• When carrying out hydrodynamic flushing, more than 98% of deposits and scale are removed from the inner surface of the heat exchanger parts, which is quite enough for the normal functioning of the device.
• This method does not damage the surface of the equipment.
• The use of ultra-high pressure systems makes it possible to increase the productivity of the work being carried out, which makes it possible to avoid significant downtime and financial losses.
• The safety and environmental friendliness of the process is due to the fact that it does not use hazardous chemicals.
• This method of cleaning produces a small amount of waste.

The use of hydrodynamic installations allows solving a number of engineering and technical problems:

1. clean heat exchangers, boilers and other equipment,
2. remove all kinds of layers, paint, dried oil products and other deposits,
3. get rid of the inner burr,
4. degrease and decontaminate the internal surface of the heat exchanger.

Causes of deposits on heat exchanger parts

During operation, various deposits accumulate on the parts of heat exchange plants and boilers. They contribute to an increase in hydrodynamic resistance and a decrease in heat transfer. As a result, efficiency is significantly reduced and costs increased. Thus, layers 2-4 mm thick on the inner surfaces of heat-releasing devices reduce the efficiency by 4-7%.

The consequences of the appearance of deposits

In addition to economic losses, the presence of significant deposits on heat exchange surfaces can lead to overheating and rupture of metal pipes, i.e., to loss of performance. For example, poor water quality, elevated levels of iron, calcium, magnesium salts, organic inclusions cause deposits on the inner surface of parts of heat exchange devices, and reduce their heat transfer and performance characteristics. In addition, the presence of scale accelerates corrosion processes.

Reasons and formula for the economic efficiency of cleaning heat exchangers

In order to calculate the cleaning efficiency of heat exchangers, several parameters must be taken into account. The final result is affected by the performance of the equipment, the amount of fuel used, the number and nature of the deposits present. With such calculations, it is necessary to test the heat exchange equipment, measure the temperature difference on a particular device. The overall economic effect can be calculated independently using the existing formula:

E - economic efficiency in monetary terms (rubles);

P - losses due to lower productivity of heat exchange equipment (rubles);

Z - the cost of cleaning (rubles).

Heat exchange devices of all types: shell-and-tube, sectional, twisted, two-pipe, lamellar, ribbed, need competent cleaning from corrosive deposits and scale. The need to flush heat exchangers appears for several reasons:

• Untimely flushing with running water leads to the accumulation of deposits.
• Routine cleaning periodic flushing of heat exchangers to prevent breakdowns and scale accumulation.
• Failure of heat exchange equipment due to irregular routine cleaning.

All technologies and materials used to clean heat exchangers and boilers are environmentally friendly for humans and the environment. They do not leave negative consequences after the end of the work. In addition, all equipment for washing heat exchangers used by VekFort specialists complies with safety norms and standards.

Before carrying out any cleaning work on heat exchangers, it is necessary to consult with VekFort specialists. Thus, it is possible to reconcile the disagreements that have arisen, to find the best option for the ratio of price and quality. In addition, VekFort consultants will make preliminary calculations of the cost of work and develop individual cleaning schemes, taking into account the nature of deposits in heat exchangers.

Examples of cleaning heat exchangers:

Flushing the heat exchanger

CIP chemical cleaning and flushing of heat exchangers

During operation, heat exchanger plates gradually become contaminated, salt deposits, scale, corrosion elements appear on them, fragments of sludge of various origins accumulate between the plates. Such processes lead to a decrease in the resource and performance of heat exchange equipment. That is why plate heat exchangers need regular maintenance and cleaning from scale and dirt. Depending on the type and quality of the media in the heat exchangers and the intensity of their work, it is recommended to carry out chemical cleaning in place at least once every 1-2 years.

When is CIP required for heat exchangers?
There are two types of cleaning of heat exchangers - in-place (chemical) and collapsible. Each method has its advantages and disadvantages and is used depending on the degree of contamination. First of all, the design of the heat exchanger influences the choice of method. Welded or semi-welded heat exchangers can only be cleaned in-place. Collapsible heat exchangers suggest the possibility of both collapsible and CIP cleaning. In this case, the choice of cleaning method depends on the degree of contamination of the plates. Before cleaning the heat exchanger, diagnostics of the equipment is carried out, media analyzes are taken, the actual parameters of the operating equipment are measured and compared with the calculated ones. Based on the results of the diagnostics, a conclusion is issued on the need for service maintenance. If the contamination is recognized as insignificant, the most effective cleaning option is CIP chemical cleaning of heat exchangers.

In the case of significant contamination and a significant pressure drop, it is recommended to carry out a dismountable chemical cleaning of the heat exchangers. In-place flushing with the use of chemical reagents is also carried out for preventive purposes during the heating and non-heating periods.

CIP method:
CIP flushing of the heat exchanger is carried out using a circulation pump unit.

Duringcleaning a special chemical reagent is used that effectively dissolves scale and plaque, as well as organic deposits, protecting the plates and seals. Under pressure, the reagent is fed into the heat exchanger, where it dissolves plaque and flushes out sludge. The final stage of CIP flushing of the heat exchanger - neutralization of the reagent and flushing of the circuits with clean water

Benefits of flushing heat exchangers in place
The main advantage of in-place flushing of heat exchangers is the speed of the procedure: disassembly of the equipment is not required; a professional service company takes no more than 4-5 hours to complete the work. Also, this technique is more gentle on seals: since there is no need to dismantle the heat exchanger, seals are not subjected to mechanical stress (especially for equipment with a long service life).

Comparison of in-place and in-place PHE flushes

Parameter	collapsible	CIP
Plate cleaning quality		High, however, due to the configuration of the plates, the presence of the so-called. "stagnant zones" in which the plates are undercleaned
Cost of work (coefficient)		(cheaper by 15-20%)
Time costs	Small (compared to CIP) on small and medium sizes, significant on large	Significant (compared to collapsible) on small and medium sizes, small on large
Gasket quality assessment	It is carried out visually, if the gaskets are worn, they may be damaged	Visually not produced, additional mechanical damage to the gaskets is not applied
Availability of additional equipment	Not required AVD "KARCHER", bath	Pump, connections
Production culture	Depends on the performing works - on the culture of placement of PTO components and equipment

Our specialists are constantly improving and applying new methods of CIP cleaning of heat exchangers and in some cases very successfully, for example:

The water pressure drop was 4 kg / cm3, which indicated very strong contamination and the need for collapsible chemical cleaning, but when disassembling the PHE, a set of gaskets of about 255 pieces would have to be replaced, and due to the considerable size of the PHE and a rare brand, the price is comparable to a new PHE of another brands, and the delivery time for such gaskets is 6-8 weeks. Our technicians applied their own PHE flushing method, which is longer (2 working days) and laborious, but the pressure drop was reduced from 4 kg/cm3 to 0.9, of course, this is not always possible, but the fact remains.

Specialists of the MZ Teplo Systems Company will carry out a full range of maintenance and cleaning of the heat exchanger. In our work, we use a special certified reagent that provides a gentle effect on the plates and gaskets of the heat exchanger and at the same time guarantees the effective removal of all contaminants.

Consider an example of flushing a brazed heat exchanger

It can be seen how the ports of the heat exchanger are clogged with scale before flushing and how after flushing

MZ Teplo Systems LLC- performs maintenance and repair of heat exchangers in Moscow and on the territory of the Central Federal District.

List of served regions: Moscow, Moscow, Kaluga, Yaroslavl, Tver, Tula, Ryazan, Tambov, Lipetsk, Tver, Smolensk, Ivanovo, Kursk, Kostroma, Vladimir, Bryansk regions, etc...

Flushing of heat exchangers is a guarantee of reliability and efficiency of their work. Heat exchangers, as well as any engineering and technical equipment, must be operated not only in compliance with technical conditions, but also with periodic cleaning of the heat exchanger.

Regardless of structural modifications, the operation of heat exchange equipment is directly dependent on the quality of the working environment. Under the influence of high temperatures, numerous salts dissolved in water form an insoluble precipitate on the internal surfaces of heat exchangers. The intensity of the formation of solid lime deposits is determined by the chemical composition of the water.

The gradual appearance of scale causes:

• Narrowing the parameters of the nominal passage;
• Reducing the intensity and uniform patency of the work flow;
• A sharp drop in heat transfer efficiency.

If you flush the heat exchanger in a timely manner, the cost of subsequent scheduled maintenance will be significantly reduced. The longest possible operation, rational and economical use of energy resources will be ensured, and various breakdowns in heat exchange equipment will be prevented.

The method and way of cleaning heat exchangers is determined by the instruction based on the principle of operation and design of the recuperative device. But the main algorithm of the collapsible method always includes the stages of dismantling, cleaning, finishing installation and requires the use of specialized equipment for washing heat exchangers, which is often necessary to buy to reduce time costs and increase the efficiency of the process.

If this is at hand, armed with additional plumbing tools, fluid for flushing heat exchangers and diligence, you can perform this procedure yourself at the place of operation.

Flushing the heat exchanger with your own hands

Before proceeding with direct execution, it should be noted that flushing the heat exchanger with your own hands is a painstaking task that does not tolerate haste and amateurism, therefore, in the absence of minimum engineering skills, it is most rational to resort to the services of service companies.

Before carrying out preventive maintenance of the heat exchanger, it should be initially taken out of operation: shut off the flow of the medium, drain the remaining coolant in the device, and dismantle the unit. When disassembling, it is highly recommended to use friction wrenches or pneumatic wrenches.

Immediately before washing the plate heat exchanger, its visual inspection is carried out, the defects found and the width of the compressed set of plates are fixed, the seal is opened (manufacturers and service companies always perform sealing).

When opening the package of plates, it is necessary to observe the parallel position of the stationary and movable plates as much as possible, respectively, the thread of the fasteners must be preliminarily cleaned and lubricated. The loosening and unscrewing of the bolts begins with the middle pair, the upper and lower bolts are also turned out in pairs, but diametrically opposite. After removing the bolts, the outer plates are moved apart and the plates are removed.

The plates are taken out carefully and only separately. If the plate heat exchanger has not been flushed for an extended period, the plates and their seals may have hardened due to high temperatures and pressures. In this case, the splitting of the plates is carried out with particular scrupulousness so as not to damage their configuration and integrity.

The plates are cleaned without seals and immediately after dismantling, since the drying of deposits increases their hardness and it will be even more difficult to remove them. With a stiff fiber brush, the plates are pre-cleaned and then immersed in the solution.

The fluid for flushing heat exchangers is selected based on the nature of the contamination:

• For organic deposits, you can simply use a solution of citric and phosphoric acid;
• For inorganic and bulk deposits, it is better to use specialized chemicals.

The time of chemical treatment depends on the selected reagent: in the first case, it will take approximately three to nine hours, in the second case, a little more than an hour.

After that, the plates are rinsed in a large amount of hot water or a jet supplied under pressure. Drying of the plates can occur naturally or with the help of a heat gun, the only condition is to avoid deformation and stress.

The dried plates are carefully inspected and wiped with a dry rag; if damaged parts are found, new ones should be ordered and installed. If damage and ruptures of seals are found, they are also replaced with new ones, taking into account the marking and color code.

The assembly of the heat exchanger is carried out in the reverse order. The package of plates is assembled taking into account the counter-parallel arrangement of the grooves. The assembled package is covered with outer plates and tightened with bolts. The tightening begins with the middle pair and ends with the alternate tightening of the upper and lower fittings.

When the package is tightened, the screed should be rechecked - the profile of the plates and seals should organize a uniform pattern, and the width should match the primary parameters.

Flushing brazed plate heat exchangers

These types are used in household systems and have an integral design, so the heat exchangers are flushed without disassembling them. If you decide to perform this procedure yourself, then according to the instructions, you will need a booster for flushing heat exchangers, the price of which is relatively small. Mechanical cleaning and many hours of soaking in acidic solutions do not provide even half the effect of its use.

The booster for flushing heat exchangers is actually a pump. It provides a closed and intensive circulation of a solution of descaling chemicals through the internal circuit.

If you have a pre-season flushing of the heat exchanger, you should buy professional reagents: Detex, Master Boiler, Docker, as this will significantly reduce the time spent on the procedure.

Miser pays twice

Despite the apparent ease of the procedure, it is not always possible to flush heat exchangers on their own with a complete restoration of their energy efficiency and functionality. In addition, do not forget that flushing the gas boiler heat exchanger is associated with the diagnosis of filtration units and the final adjustment of the electronics. A poorly selected acid for washing heat exchangers can cause chemical corrosion of metal parts and destruction of rubber seals.

Service maintenance of heat exchangers allows:

• Promptly and efficiently flush heat exchangers;
• Minimize the risks associated with incorrect and emergency operation of devices;
• Eliminate the possibility of damage to structural elements and associated communications;
• Choose the most effective cleaning method (hydrodynamic, mechanical or chemical washing of heat exchangers).

Each model of heat exchange equipment is designed for a certain pressure value, a certified installation for flushing heat exchangers allows cleaning with absolute matching of parameters and thereby completely eliminating a decrease in the dynamic strength of the device.