If the boiler is shut down for a long time, then it must be preserved. When preserving boilers, it is necessary to follow the instructions of the manufacturer's instructions for installation and operation.

To protect boilers from corrosion, dry, wet and gas preservation methods are used, as well as, in some cases, overpressure preservation methods.

Dry method conservation is used when the boiler is stopped for a long time and when it is impossible to heat the boiler room in winter. Its essence lies in the fact that after removing water from the boiler, superheater and economizer and cleaning the heating surfaces, the boiler is dried by passing hot air (thorough ventilation) or a small fire is made in the furnace. Wherein safety valve must be open to remove water vapor from the drum and boiler pipes. If there is a superheater, open the drain valve on the superheated steam chamber to remove the remaining water. After the end of drying, pre-prepared iron trays with quicklime CaO or silica gel (in the amount of 0.5-1.0 kg of CaC12, 2-3 kg of CaO or 1.0-1.5 kg of silica gel per 1 m3 of boiler volume). The drum manholes are tightly closed and all fittings are closed. When the boiler is shut down for more than 1 year, it is recommended to remove all fittings and install plugs on the fittings. In the future, the state of the reagents should be checked at least once a month, and then every 2 months, depending on the results of the check, it must be replaced. It is recommended to periodically monitor the state of the lining and, if necessary, dry it.

Wet way. Wet preservation of boilers is used when there is no danger of water freezing in them. Its essence lies in the fact that the boiler is completely filled with water (condensate) with increased alkalinity (the content of caustic soda is 2-10 kg / m air and dissolved gases and tightly close the boiler. The use of an alkaline solution ensures sufficient stability at a uniform concentration protective film on the metal surface.

Gas method... At gas method preservation, drain water from the cooled boiler, thoroughly clean the inner heating surface from scale. After that, the boiler is filled through an air vent with gaseous ammonia and a pressure of about 0.013 MPa (0.13 kgf / cm2) is created. The action of ammonia is that it dissolves in a film of moisture that is on the surface of the metal in the boiler. This film becomes alkaline and protects the boiler from corrosion. With the gas method, the personnel performing the conservation must know the safety rules.

Overpressure method consists in the fact that in the boiler, disconnected from the steam lines, the steam pressure is maintained slightly above atmospheric and the water temperature is above 100 ° C. This prevents air and therefore oxygen from entering the boiler, which is the main corrosive agent. This is achieved by periodically heating the boiler.

When the boiler is brought into a cold reserve for up to 1 month, it is filled with deaerated water and a slight excess hydrostatic pressure is maintained in it by connecting it to the tank with deaerated water located above. However, this method is less reliable than the previous one.

For all methods of preserving boilers, it is necessary to ensure complete tightness fittings; all hatches and manholes must be tightly closed; in the dry and gas method, idle boilers must be separated from the working ones with plugs. Equipment conservation and its control are carried out according to special instructions and under the guidance of a chemist.

You can order products for the preservation of boilers and equipment from us!

The concept of conservation is usually associated with food, which is understandable. The average consumer is faced with this form of preservation of the original characteristics much more often. In other areas, this approach to the maintenance of objects can be considered as one of the inventory tools. This is how the conservation of equipment at enterprises is characterized, which provides not only for the implementation of the technical side of the matter, but also for compliance with the relevant legal standards.

What is preservation of production equipment?

Situations are quite common when they remain unused for a while. This can be part of the technical equipment at the enterprise, or the entire infrastructure with equipment. In any case, leaving the equipment for a long time is possible only if it is properly prepared, which is preservation. This is a set of measures aimed at ensuring the safety of equipment characteristics for a certain period. That is, it is assumed that, for example, machines and units at this time will not be operated and will not be subject to repair and maintenance measures.

It is important to take into account that conservation of equipment is not a means of passive protection against external influences... Depending on the storage conditions, it may be necessary to special treatment metal surfaces, rubber elements and other equipment parts. From this point of view, conservation is also a preventive means of maintaining an object in good condition.

Legal registration of the procedure

Preparation for the conservation process begins with the implementation of formal procedures. In particular, the preparation of documentation is necessary so that in the future it remains possible to recognize all the costs of the implementation of the event. The initiator of conservation can be a representative of the service personnel, who submits an appropriate application to the name of the manager. Next, an order is drawn up for the allocation Money on the procedure and an instruction is given on the development of the project, in which the requirements for conservation from the side of technical services will be noted. As for the legal requirements, representatives of the administration, the leadership of the department responsible for objects, economic services, etc., should control the process of transferring equipment to storage. economic feasibility project and make up an estimate for the maintenance of objects.

Technical execution of conservation

The whole procedure consists of three stages. The first stage removes all kinds of contaminants from the surfaces of the equipment, as well as traces of corrosion. If necessary and available technical capability repair operations can also take place. This stage is completed by measures for surface degreasing, passivation and drying. The next stage involves processing protective equipment, which are selected based on individual operating requirements technical means... For example, preservation of boilers may involve treatment with high-temperature compounds, which in the future will provide the structure with optimal resistance to impact. high temperatures... Versatile treatments include anti-corrosion powders and a liquid inhibitor. The final stage involves

Performing re-preservation

During storage, the responsible services periodically conduct inspections of the equipment, assessing its condition. In case of traces of corrosion or other defects on the surfaces of the equipment, re-preservation is carried out. This event also involves the implementation of primary surface treatment in order to remove traces of damage to metal or other materials. In some cases, re-conservation takes place - this is the same set of preventive measures, but in this case it has a planned nature of implementation. For example, if a protective composition with a certain service life is applied, then after this period, the technical service must renew the product within the same re-preservation.

What is de-preservation?

When the time allotted for conservation has expired, the equipment undergoes the reverse process, which involves preparation for operation. This means that preserved parts must be freed from temporary protective compounds and, if necessary, treated with other means suitable for use with work equipment. It is worth noting the need for taking precautions. Like technical preservation, de-preservation should be carried out under conditions that meet the requirements for the use of degreasing, anti-corrosion and other compounds that are sensitive to temperature and humidity. Also, when performing such procedures, special standards for ventilation are usually observed, but this depends on the specifics of the specific equipment.

Conclusion

The conservation procedure undoubtedly has many advantages, and its implementation is mandatory in many cases. Nevertheless, it does not always justify itself from a financial point of view, which determines the involvement of the accounting department in the preparation of the corresponding project. Nevertheless, conservation is a set of measures aimed at maintaining the operability of equipment in order to obtain benefits for the enterprise. But if it comes about unused or unprofitable objects, then there is no sense in carrying out such activities. For this reason, the stage of preparation and development of a project for transferring equipment to a preserved state is to some extent even more responsible than practical implementation procedures.

RD 34.20.593-89

INSTRUCTIONS
ON THE APPLICATION OF CALCIUM HYDROXIDE FOR PRESERVATION
HEAT POWER AND OTHER INDUSTRIAL EQUIPMENT
AT THE OBJECTS OF THE USSR MINISTRY OF ENERGY

Valid from 01/01/89
until 01.01.99 *
__________________
* For the expiration date, see the "Notes" label. -
Database manufacturer's note.

WORKED BY the All-Union Intersectoral Research Institute for the Protection of Metals from Corrosion, REU "Mosenergo", 1st Moscow Order of Lenin and the Order of the Red Banner of Labor medical institute them. I.M.Sechenov

PERFORMERS A.P. AKOLZIN (All-Union Intersectoral Research Institute for the Protection of Metals from Corrosion), G. A. SHCHAVELEVA (REU "Mosenergo"), Y. Y. KHARITONOV (1st MMI)

APPROVED by the Main Scientific and Technical Directorate of Energy and Electrification on 12/30/88

Deputy Head A.P. BERSENEV


These Guidelines set out a method for protecting heat and power equipment from parking corrosion when it is put into reserve, as well as during emergency and planned shutdowns.

Preservation with calcium hydroxide solution is used for any hot water boilers and for steam drum boilers with pressures up to 4.0 MPa that do not have superheaters, as well as for steam boilers with superheaters, but the superheaters themselves are not preserved.

The guidelines apply to stationary power plants, heating boiler houses, enterprises with hot water and steam power boilers with pressures up to 4.0 MPa, and must be taken into account by design organizations.

Based on these Guidelines, enterprises draw up local work instructions for conservation.

When preserving the equipment, it is necessary to observe the current "Safety Rules for the Operation of Thermal Mechanical Equipment of Power Plants and Heating Networks" (M .: Energoizdat, 1985), as well as the precautions set forth in Section 4.

1. CHARACTERISTIC OF THE METHOD FOR PRESERVATION OF HEAT POWER EQUIPMENT WITH CALCIUM HYDROXIDE

1. CHARACTERISTIC OF THE PRESERVATION METHOD
HEATING EQUIPMENT WITH CALCIUM HYDROXIDE

1.1. The method of protection against parking corrosion (conservation) of heat and power equipment, based on the use of inhibiting solutions of calcium hydroxide, is highly effective.

1.2. Calcium hydroxide (see reference annex) is a non-funded local product which makes it widely available. It is also a waste of a number of industries (for example, welding). Calcium hydroxide solutions are harmless to humans and environment... When discharging waste solutions, it is required to dilute them with water to pH<8,5. Вследствие малой растворимости (около 1,4 г/л при 25 °С) создать концентрации раствора гидроксида кальция, опасные для жизни и здоровья человека, практически невозможно. Кроме того, в естественных условиях (водоемах, почвах) происходит быстрая нейтрализация гидроксида кальция путем его взаимодействия с углекислым газом атмосферы, в результате чего образуется карбонат кальция (мел), также безопасный для здоровья человека.

1.3. The effectiveness of the protective action of calcium hydroxide solutions against the metal of heat and power equipment in all respects is significantly higher than that of a number of other inhibitors.

For example, the corrosion rate of steel in the presence of calcium hydroxide (protective concentration, see clause 1.4) in environments containing up to 3 g / l of chlorides is 1.5-2.2 times lower than in sodium silicate solutions, and 10 -12 times lower than in sodium hydroxide solutions at the same equivalent concentration of inhibitors. The corrosion rate was determined gravimetrically and by the method of polarization resistance.

1.4. The protective concentration of calcium hydroxide solutions in relation to equipment made of carbon steel is 0.7 g / l and higher.

Overdose is impossible due to its limited solubility.

1.5. With long-term conservation (more than a month) under conditions of contact of the preservative solution with air, its concentration gradually decreases due to the absorption of acidic components of the air. A decrease in pH to less than 8.3 is unacceptable, since it indicates the appearance of carbonates, bicarbonates and hydrosulfites in the preservative solution, i.e. products of interaction of calcium hydroxide with air constituents. The result of this interaction is a decrease in the protective effect. The control of the preservative solution is carried out by taking samples at least 1 time per week. When the pH of the solution drops below the permissible level (the disappearance of color for phenolphthalein), the preservative solution should be renewed.

In the absence of contact with air, the protective properties of the solution are not limited by time.

1.6. The presence of corrosion activators (chlorides in a concentration of up to 0.365 g / l and sulfates up to 0.440 g / l) in a calcium hydroxide solution with a concentration of 0.7 g / l and above practically does not reduce the protective properties of preservative solutions. This is due to the fact that a phase protective film with a thickness of 12-21 μm is formed in calcium hydroxide solutions on the surface of carbon steel, consisting of insoluble hydroxo and aqua complexes of iron and calcium, which also includes other compounds and ions.

1.7. If bicarbonates are present in an aqueous preservative solution (when preparing a solution on river water), the protective properties of the films formed on steel increase due to the additional formation of calcium carbonate (chalk) layers.

1.8. The preservative solution is prepared in water with a temperature below 40 ° C, since as the temperature rises, the solubility of calcium hydroxide in water decreases and the protective properties of the solution decrease.

2. TECHNOLOGY OF PRESERVATION

2.1. Preservative solutions of calcium hydroxide are prepared from milk of lime. At the VPU with pretreatment, you can use a lime solution prepared for clarifiers.

2.2. For the preparation of milk of lime, almost any slaked lime can be used, including construction lime, with preliminary removal of the undershot; fluff lime; waste quenching of calcium carbide in the production of acetylene. Slaked lime and milk of lime should not contain sand, clay and other contaminants insoluble in water (see clauses 2.5, 2.6, 2.8).

2.3. Preservative solutions are prepared on condensate or chemically purified water. Sea and boiler water is not suitable for the preparation of preservative solutions.

2.4. The preservative solution is prepared in a separate supply tank with a volume of 20-70 m. It is more convenient when the volume of the supply tank exceeds the volume of the equipment to be preserved. The amount of slaked lime supplied to the supply tank for the preparation of the preservative solution is 1-1.5 kg per 1 m of water in the tank. Preliminarily, lime is stirred with water to a liquid consistency, then the mixture is poured into the tank through a mesh with cells of no more than 1 mm to retain solid impurities.

2.5. In the tank, the preservative solution is allowed to settle for 10-12 hours until the reagent is completely clarified and dissolved.

2.6. The preservative solution can be fed from the supply tank to the boiler by gravity. For this, the tank is installed above the boiler. If the supply tank is at the bottom, the boiler is filled with pumps.

2.7. The selection of preservative solutions is carried out not from the lower point of the supply tank, but from a level of 40-50 cm from the bottom of the tank in order to avoid the ingress of solid insoluble particles into the boiler. For the same purpose, before feeding into the boiler, preservative solutions are passed through any mechanical filter.

2.8. The preservative solution is fed into a completely drained and cooled boiler. Preservation can be carried out both on a chemically or mechanically cleaned boiler, and on a boiler with internal deposits. The solution is fed through the lower collectors of the boiler.

2.9. The entire internal volume of the boiler is filled with a preservative solution. If a hot water boiler has a closed circulation loop, then the entire circuit, including pipelines and heat exchangers, is filled with a preservative solution. In drum boilers, water economizers, guard and downpipes and the boiler drum are filled.

2.10. If the amount of solution prepared in the supply tank is not enough to fill the entire boiler, the next portion of the preservative solution is prepared in the supply tank in accordance with paragraphs 2.4-2.8.

2.11. For hot water boilers, it is advisable to provide stationary systems for the preparation of preservative solutions and their supply to the boiler. Possible schemes for the preparation and supply of preservative solutions are shown in Figs. 1, 2. In Fig. 1, for the preparation of solutions, the scheme has a saturator tank. There is also a filter (for example, of the type of a salt water treatment solvent). Fig. 2 shows another variant of conservation, which provides for the supply of a preservative solution using the acid washing scheme for hot water boilers.

Fig. 1. Scheme of adding calcium hydroxide to canned equipment

Fig. 1. Scheme for introducing calcium hydroxide into canned equipment:

1 - filling funnel; 2 - tank for the preparation of lime milk; 3 - preservative preparation tank
calcium hydroxide solution; 4 - filter; 5 - supply tank; 6 - ejector; 7 - feed pump; I - condensate;
II - chemically purified water; III - steam; IV - sampling before the introduction of calcium hydroxide; V - sampling after
calcium hydroxide injection; VI - from the feed tanks; VII - for boilers

Fig. 2. Scheme of preservation of hot water boilers with Ca (OH) solution (2) using acid washing scheme

Fig. 2. Scheme of preservation of hot water boilers with a solution using the acid washing scheme: If the payment procedure on the payment system website has not been completed,
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REGULATORY DOCUMENTS FOR THERMAL POWER PLANTS AND BOILER BOILERS

INSTRUCTIONS FOR
CONSERVATION OF HEAT-MECHANICAL
EQUIPMENT WITH APPLICATION
FILM FORMING AMINES

RD 34.20.596-97

INDUSTRY GUIDANCE DOCUMENT

This Industry Guidance Document:

Developed in accordance with the requirements of the Rules for the technical operation of power plants and networks of the Russian Federation (RD 34.20.501-95);

It applies to the main thermal and mechanical equipment of thermal power plants and establishes the method of conservation and the sequence of operations for its implementation during various types of shutdowns (planned and emergency shutdowns, shutdowns for current, medium and major repairs, shutdowns in reserve for a certain and indefinite period);

Designed for operating personnel of TPPs, hot water boilers, personnel of adjustment enterprises, power equipment manufacturers, design and research organizations.

1. GENERAL PROVISIONS

1.1. Conservation of heat and power equipment (boilers, turbines, heaters) using amine-containing compounds is carried out to protect steam-water ducts from atmospheric corrosion in the following cases:

Short-term planned or emergency shutdowns;

Stops for maintenance, medium or major repairs:

Putting equipment into reserve;

When decommissioning equipment for a long time.

1.2. The protective effect is provided due to the creation of a molecular adsorption film of a preservative on the internal surfaces of the equipment, which protects the metal from the effects of oxygen, carbon dioxide, and other corrosive impurities and significantly reduces the rate of corrosion processes.

1.3. The choice of the parameters of the conservation process (time characteristics, concentration of the preservative, etc.) is carried out on the basis of a preliminary analysis of the state of the equipment of the power unit (specific contamination of surfaces, composition of sediments, conducted water chemistry, etc.).

1.4. During conservation, an accompanying partial washing of the steam-water ducts of the equipment from iron and copper-containing deposits and corrosive impurities is carried out.

1.5. The quality of preservation is assessed by the value of the specific sorption of the preservative on the surface of the equipment, which should not be lower than 0.3 μg / cm 2. Whenever possible, gravimetric studies of witness samples are carried out and electrochemical tests of cut samples are performed.

1.6. The advantages of this conservation technology are as follows:

Reliable protection of equipment and pipelines is provided, including in hard-to-reach places and stagnant zones, from the occurrence of parking corrosion for a long period of time (for a period of at least 1 year);

Equipment start-up time is significantly reduced. operation;

Provides the ability to implement corrosion protection not only for specific equipment separately, but also for the entire set of this equipment, i.e. the energy block as a whole;

The corrosion-protective effect remains after drainage and opening of the equipment, as well as under a layer of water;

No special measures for re-conservation are required, quick re-commissioning of both individual elements and all mothballed equipment as a whole is ensured;

Allows to carry out repair and maintenance work with equipment opening;

Conservation is carried out without significant time labor costs, heat and water consumption;

Environmental safety is ensured;

The use of toxic preservatives is excluded.

1.7. On the basis of these guidelines, at each power plant, a work instruction for the conservation of equipment must be drawn up and approved, with a detailed indication of measures to ensure the strict implementation of the conservation technology and the safety of the work performed.

2. INFORMATION ABOUT PRESERVATIVE

2.1. To carry out conservation, the preservative produced by the domestic industry is used flotamine (octadecylamine stearic technical), which is one of the highest film-forming aliphatic amines. It is a waxy white substance, the main properties of which are given in TU-6-36-1044808-361-89 dated 20.04.90 (instead of GOST 23717-79). Along with the domestic preservative, a foreign analogue of ODACON (condensation ODA) of increased purity can be used, corresponding to the European standard DIN EN ISO 9001: 1994 with the following main parameters:

2.2. The sampling of the preservative and the acceptance rules must be carried out in accordance with GOST 6732 (organic dyes, intermediate products for dyes, textile auxiliary substances). The indicators of the technical requirements provided for by the TU correspond to the world level and the requirements of consumers.

2.3. The maximum permissible concentration of flotamine in the air of the working area should not exceed 1 mg / m 3 (GOST 12.1.005-88).

Russian joint stock company
energy and electrification "UES of Russia"

Department of Science and Technology

INSTRUCTIONS
FOR CONSERVATION
HEAT POWER EQUIPMENT

RD 34.20.591-97

Expiration date set

from 01.07.97 to 01.07.2002

Designed by company for the adjustment, improvement of technology and operation of power plants and networks "ORGRES" and JSC VTI

PerformersIN AND. Startsev (JSC "Firm ORGRES"), E.Yu. Kostrikina, T. D. Modestova (JSC VTI)

Approved byDepartment of Science and Technology of RAO "UES of Russia" 02/14/97

Head A.P. BERSENEV

These Guidelines apply to power and hot water boilers, as well as turbine installations of thermal power plants.

The methodological guidelines determine the main technological parameters of various conservation methods, establish criteria for choosing methods or combinations (combinations) of methods, the technology for their implementation on boilers and turbine plants when withdrawing to reserve or repair, taking into account a sharp increase in both the number of shutdowns and the duration of equipment downtime at power plants.

With the introduction of these Guidelines, “Guidelines for the conservation of heat and power equipment: RD 34.20.591-87” (Moscow: Rotaprint VTI, 1990) are no longer valid.

1. GENERAL PROVISIONS

The water discharged from the boiler must be used in the steam-water cycle of the power plant, for which it is necessary to provide for pumping of this water to neighboring blocks at block power plants.

During processing, the hydrazine content is monitored by taking water samples from a sampling point on the feed water line in front of the boiler.

At the end of the specified processing time, the boiler is stopped. When shutting down in reserve for up to 10 days, the boiler can not be drained. In the event of a longer downtime, a CO should be performed after hydraulic fracturing.

At the end of the FV, the boiler is stopped and after the pressure drops to atmospheric, it is emptied, directing the solution to neutralization.

2.7.8 ... The boiler, brought out into reserve and emptied, is filled with a preservative solution through the lower points of the screens and drainage E. The filling of the boiler is controlled by means of air vents.

If the solution is mixed in the boiler by recirculation (see Fig. 1), then the end of it is determined by equalizing the concentration of the solution at the sampling points along the steam-water path.

After filling the boiler, close all the shut-off valves of the steam-water path.

2.7.9 ... During the conservation period of the boiler, the tightness of the closure of valves and gates is regularly checked, leaks and leaks of glands are promptly eliminated.

In case of partial emptying, the boiler is fed with a fresh solution of reagents.

2.7.10 ... At the end of the conservation, the solution from the boiler is drained into the reagent tank, using, if necessary, to fill another preserved boiler or directing it to the neutralization unit.

If the boiler was preserved with a solution of sodium hydroxide with trisodium phosphate, before firing up, the superheater is washed with water for 30 - 60 minutes with water being discharged through the lower points of the boiler. The steam superheater flushing line must be reliably disconnected from the operating boiler.

2.8. Filling the boiler heating surfaces with nitrogen

2.8.1 ... Filling the internal heating surfaces with chemically inert nitrogen followed by maintaining its excess pressure in the boiler prevents oxygen access, which ensures the stability of the previously formed protective film on the metal for a long time.

2.8.2 ... The boiler is filled with nitrogen at overpressure in the heating surfaces. During the conservation process, the nitrogen flow rate must ensure a slight overpressure in the boiler.

2.8.3 ... Nitrogen conservation is used on boilers of any pressure at power plants that have nitrogen from their own oxygen plants. At the same time, it is allowed to use nitrogen at its concentration of at least 99%.

2.8.4 ... Filling with nitrogen is carried out when the boiler is put into reserve for a period of up to one year.

2.8.5 ... The conservation scheme should provide for the supply of nitrogen to the outlet headers of the superheaters and to the drum through the air vents.

The supply to the air vents is carried out by means of tie-in pipes with high-pressure fittings. The outlets from the air vents should be combined into a common collector, which is connected to the nitrogen supply pipeline. The collector that combines the branches from the air vents must be reliably disconnected from the nitrogen pipeline by installing high pressure fittings. On this manifold it is necessary to have an inspection valve open during the operation of the boiler.

The specific layout of nitrogen pipelines is developed taking into account the capabilities of the oxygen plant and the types of installed boilers.

2.8.6 ... When the boiler is shut down for up to 10 days, conservation is carried out without draining the water from the heating surfaces.

After stopping the boiler and reducing the pressure in the drum to 0.2-0.5 MPa, open the valves on the nitrogen supply lines to the superheater and to the drum and proceed, if necessary, to drain the boiler, after which the drains are closed.

During the conservation process, the gas pressure in the boiler is maintained at the level of 5 - 10 kPa.

2.8.7 ... During the conservation period, measures are taken to identify possible gas leaks and eliminate them.

2.8.8 ... If it is necessary to carry out minor repairs, a short-term interruption of the gas supply to the boiler is possible.

2.9. Preservation of the boiler with a contact inhibitor

2.9.1 ... Contact inhibitor M-1 is a salt of cyclohexylamine and synthetic fatty acids.

In the form of an aqueous solution, a contact inhibitor (CI) protects cast iron and steel of various grades against corrosion. Its protective properties are due to the presence of amino groups in the inhibitor in the hydrophobic part of the molecule. Upon contact with the metal surface, the inhibitor is adsorbed at the amino group, leaving the hydrophobic part of the molecule in the external environment. This structure of the adsorption layer prevents the penetration of moisture or electrolyte to the metal. An additional obstacle is the overlying layers of inhibitor molecules, which enhance the adsorption layer. Water and gas molecules penetrating deep into this layer ( S О 2, СО 2, etc.) lead to hydrolysis of a part of the inhibitor molecule. This liberates cyclohexylamines and fatty acids. Cyclohexylamines bind acid gases, and acids, being adsorbed, maintain the hydrophobicity of the metal surface.

The contact inhibitor creates a protective film on the metal, which remains even after the preservative solution has been drained.

2.9.2 ... To preserve the heating surfaces, the boiler is filled with an aqueous solution of an inhibitor with a concentration of 0.5 - 1.5%, depending on the duration of the downtime, the composition and amount of deposits on the heating surfaces. The specific concentration of the inhibitor solution is established after a chemical analysis of the composition of the deposits.

2.9.3 ... KI conservation is used for all types of boilers, regardless of the applied modes of corrective treatment of feed and boiler water.

2.9.4 ... Preservation with M-1 inhibitor is carried out when the boiler is taken into reserve or under repair for a period of 1 month or more. up to 2 years.

2.9.5 ... To carry out conservation, a special separate scheme for preparing an aqueous solution of the inhibitor and feeding it into the boiler should be provided (Fig. 3). The scheme includes a tank for storing and preparing a solution with a capacity of at least the full water volume of the boiler and a pump for mixing the solution and supplying it to the boiler. The tank must be supplied with condensate or demineralized water.

The boiler is filled with an inhibitor solution through the pipeline from the pressure side of the pump to the lower drainage header of the boiler. Through the same pipeline, the preservative solution from the boiler is discharged into the storage tank during re-preservation.

2.9.6 ... To prepare a working solution, flasks with a commercial inhibitor are preheated by dropping them into a bath with water heated to 70 ° C. The approximate warm-up time is 8 - 10 hours.

The heated commercial inhibitor is poured into the tank of the preservative solution during water recirculation according to the "tank - pump - tank" scheme. The circulating water temperature should be around 60 ° C. The circulation time of the solution is 1 h. The concentration of the inhibitor in the working solution is determined in accordance with the application procedure.