Method for cleaning internal surface of boiler

FIELD: chemistry.

SUBSTANCE: invention can be used in the operational cleaning of the internal surfaces of small and medium-pressure water boilers and steam boilers not exceeding 15 atm from the deposits, including high-temperature silicates, calcium, and magnesium phosphates, and insoluble or hardly soluble in mineral acids. Water prepared is used as a cleaning solution after Na-cationization with a total alkalinity of 4-6 mg*ekv/dm3, and a total hardness of 0.002 mg*EQ/dm3 at a temperature of 60-90C with pH of 7.0 and 8.5, with the addition of a complexing agent - "Trilon B" - disodium salt of ethylenediaminetetraacetic acid and phosphate, the concentration of which in the boiler water is raised to 50-168 mg/dm3 of disodium salt of ethylenediaminetetraacetic acid, and 10-20 mg/dm3 of PO43, respectively. The dosage of "Trilon B" and phosphate is carried out by two independent pumps into the suction header of the boiler feed pump. Boiler purge is carried out according to the constant analytical control, maintains the level of hardness and salt content of the boiler water in accordance with the technical requirements of the boiler.

EFFECT: improving the environmental characteristics of the cleaning process by eliminating the formation of aggressive wastewater, cleaning during the operation of the equipment.

3 cl, 1 tbl

 



 

Same patents:

FIELD: power industry.

SUBSTANCE: in the method of steam and chemical cleaning and passivation of surfaces of metal pipes which is characterized by their purging with water vapour with oxidizer and activators of cleaning process into the water vapour flow during their purging first the reagent is added which emits carbon oxide - water solution of formic acid, then hydrogen and at the end of the process oxygen is added.

EFFECT: improvement of efficiency of cleaning and passivation of internal surfaces of heat exchange pipes due to performing the process in three stages at consecutive dosing in the flow of steam of reagent of the formic acid decayed with release of carbon oxide in the following sequence: formic acid, hydrogen and oxygen.

FIELD: process engineering.

SUBSTANCE: invention relates to cleaning the heat exchanger surfaces of scale and corrosion. This process involves application of ascorbic acid, complexing agent, water and, possibly, auxiliary additives to be forced or pouted via heat exchanging hardware. Cleaning composition is fed from expansion tank of cavitation-thermal generator. The latter allows a hydrodynamic heating of cleaning fluid to 70-130C and swirling of liquid by hydrodynamic cavitation. Note here that before application of said composition heat exchange hardware is filled with water to be heated by cavitation-thermal generator to 50-70C.

EFFECT: higher power and process efficiency, decreased consumption of cleaning composition, non-polluting process.

3 cl, 6 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method for cleaning involves dividing a heat exchange system on the following circuits: a loop of the diesel water cooling system, a loop of air-water radiator sections of the water cooling system of the locomotive diesel and turbo compressor, a loop of air-water radiation sections of the water cooling system of oil and charging air, a turbo compressor loop, a charging air coolant loop, an oil-water heat exchange loop, an oil heater loop, and an operator's cab heater loop. That is combined with the separate washing of each of the above loops with a washing agent at its temperature of 50-80C with periodic change in the solution flow direction through the loop cavity, neutralisation of the agent solutions and anti-corrosion treatment. The washing solution is a solution containing, wt %: sulphamic acid - 2-5, ethylene diamine tetraacetic acid disodium salt - 1-1.5, a corrosion inhibitor - 0.1-0.2, water - the rest.

EFFECT: more effective cleaning of the heat exchange systems, higher operability, improved anticorrosion properties of the treated surfaces and safety of the method.

9 cl, 2 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: method includes washing the cavity to be treated with a solution of a washing reagent at 50-80C and periodically changing the direction of flow through the cavity, wherein the solution used has components in the following ratio, wt %: sulphamic acid - 2-5, disodium salt of ethylendiaminetetraacetic acid - 1-1.5, corrosion inhibitor - 0.1-0.2, water - the balance. The solution of the washing reagent is then neutralised with sodium hydroxide solution, followed by anti-corrosive treatment of the cavity by washing with a passivating solution.

EFFECT: high effectiveness of the action of the treating liquid on the internal surface of a cavity of heat-exchange equipment.

10 cl, 1 dwg

FIELD: heating.

SUBSTANCE: method of cleaning heat exchanger from carbonate deposits is provided, comprising feeding of geothermal water with a concentration of carbon dioxide above the equilibrium value, which is generated by increasing the total, respectively, and the partial pressure of carbon dioxide in the cleaned heat exchanger. The cleaned heat exchanger is connected in series to the clean the heat exchanger, and from the geothermal water before feeding to the clean heat exchanger a part of carbon dioxide is removed to the equilibrium value and fed into the geothermal water before feeding to the cleaned heat exchanger, the partial pressure of carbon dioxide in the cleaned heat exchanger is maintained at a level above the equilibrium value.

EFFECT: invention enables to improve the efficiency of cleaning the heat exchanger and to avoid heat loss of geothermal water used for hot water supply.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention is related to oil production and may be used for paraffin deposits removal from heat exchangers at oil heating unit. Method of paraffin deposits removal from heat exchangers consist in removal of heated and liquefied paraffin by hot oil flow, at that the line of reverse oil delivery is connected to heat exchangers and at pressure drop between oil pressure at the input to heat exchangers and pressure at their output from 0.9 up to 0.95 of the maximum allowable value for these heat exchangers oil delivery is switched from their input to the output thus forming the reverse oil flow mode, which is maintained till the preset pressure drop is attained at each heat exchanger at the oil heating unit, thereupon oil delivery is switched to the input of heat exchangers.

EFFECT: design simplification of the oil heating unit both in operation mode and cleaning mode with permanent heated oil delivery to consumers.

1 dwg

FIELD: chemistry.

SUBSTANCE: disclosed is a method of cleaning the inner surface of boiler tubes via treatment thereof in a separate loop with a hot water-based cleaning medium with addition of a chemical agent in form of an aqueous solution of a disodium salt of ethylenediaminetetraacetic acid. Said hot medium is boiler water at temperature of 90-100C; the aqueous solution of said chemical agent is added to said medium for 40-80 minutes until achieving concentration thereof in the boiler water of 1.0-1.2 wt % at pH=5.0-6.0. Post-treatment and passivation of the inner surface of the boiler tubes is then carried out by switching to boiler operation in starting conditions while raising pressure and temperature of the boiler water at pH=8.8-9.3 to 3.0-25.0 MPa and 150-420C, respectively, and feeding oxygen with concentration of 1.8-2.2 g/dm3 into the boiler water for 9-12 hours and gradually removing said chemical agent from the treated loop for 40-80 minutes.

EFFECT: high reliability of operation of explosion-proof devices in case of accidental explosion at a facility and reduced release of hazardous substances into the atmosphere.

3 dwg, 3 tbl

FIELD: power engineering.

SUBSTANCE: proposed method comprises processing of pipes in isolated circuit by hot detergent water-based solution containing nitrogen-bearing chemical reagent. Said nitrogen-bearing chemical reagent represents a film-forming amine while batching of detergent solution is performed at concentration of chemical reagent in the boiler of (250300) mcg/dm3. Cleaning is performed in one step at boiler pressure of 1.52.5 MPa and working fluid temperature not exceeding 230C to stabilisation of iron content in boiler water. Passivation is performed at boiler pressure of 2.515.5 MPa and working fluid temperature equal to saturation temperature for boiler pressure to stabilisation of iron content in boiler water not exceeding 50 mcg/dm3.

EFFECT: lower costs.

2 cl, 2 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to cleaning outer aluminium surfaces of air cooling hardware. Proposed method comprises processing of surface with detergent and flushing with water. Note here that cleaning is conducted in three steps. At first and third steps, surface is flushed with heated water or the mix of water with steam at jet pressure of 20-150 bar. At second step, surface is flushed with 0.25-1.5% water solution of acidic detergent heated to 20-60C at jet pressure of 20-150 bar and duration of 10-30 minutes. Used detergent comprises the following substances at the following ratio of components in wt %: orthophosphoric acid - 20.0-25.0, nitric acid - 8.0-15.0, oxyethylidenediphosphorus acid - 2.0-4.5, non-ionic surfactant - 0.05-0.11, water making up to 100. At first and third steps, surface is flushed with water heated to 20-100C or with mix of water with steam heated to 100-155C.

EFFECT: higher efficiency of cleaning the surfaces located between heat exchanger ribs.

3 cl, 6 ex

FIELD: heating.

SUBSTANCE: device for leakage check, flushing and determining the heat emission of vehicle radiators relates to washing equipment and can be used to clean radiators of cooling systems for internal combustion engines. The device comprises a test chamber, tubular electric heaters, a tank, a compressor, a circulation pump, a filter and pipelines, a clamp for a radiator with a removable top allowing for the installation of radiators of different dimensions in it, a manually controlled four-position distributor, a drain tap.

EFFECT: device allows for check of leakages, flushing of a radiator and determination of the heat emission factor.

1 dwg

FIELD: heat-and-power engineering, may be used for refinement and passivation of steam turbines' setting or for the purpose of their temporary closing-down or increasing effectiveness of exploiting.

SUBSTANCE: refinement and passivation is carried out by processing of the surface of the setting by oxygen-steam mixture under definite temperature mode of operation. The setting is processed at revolving rotor at that the steam temperature at turbine's exit is below 180°C. Processing is made in series - at free-running during 2-6 hours at the temperature of 70-300°C at the turbine's exit, then under load within the limits of 10-40% of nominal during 7-10 hours at the temperature within the limits of 400-540°C at turbine's entry.

EFFECT: provides possibility for refinement and passivation of steam turbine's setting by the most effective and environmentally appropriate mode.

3 ex

FIELD: sugar industry.

SUBSTANCE: method comprises preparing solution of hydrochloric acid with inhibitor in a tank, alternating heating and cooling the surface of the evaporator by circulating the solution prepared by means of a pump from the tank to the evaporator.

EFFECT: enhanced efficiency.

2 ex

FIELD: the invention refers to heat-and-power engineering particularly to the mode of cleansing inner surfaces of heat exchangers from scale deposit.

SUBSTANCE: the mode includes dilution of acid-forming gas in water by way of water-gas ejection, creation of overpressure with the aid of gas of water solution until magnitude higher then hydrostatic resistance of heat exchanger and throwing down this pressure. After ejection of formed water-gas dispersion additional rotationally-whirling motion is given, then overpressure is dropped at least once until forming of cavitational bubbles then it is once more raised until its initial meaning. At that acidation of water solution is made.

EFFECT: provides reduction of harmful impacting of acids on environment, excludes possible stopping of tubes with flinders of scale sediment due to complete dispersion of scale.

6 cl, 2 dwg

FIELD: heat power engineering, applicable for cleaning and protection against scale and corrosion of inner heating or heat-exchange surfaces of hot-water and steam boilers and heat exchangers, heating-water converter plants, accelerators, heat supply routes, heating systems of dwellings and industrial objects, cooling systems of internal combustion engines in the process of service.

SUBSTANCE: the method consists in treatment of the inner heating or heat-exchange surfaces by solutions at a cyclic or multiple circulation of them in the system with a subsequent removal of scale, an aqueous solution of a special repair=reducing composition is used for the purpose, it consists of rocks finely divided to a dispersity of 0.07 to 0.075mm including oxides of elements SiO2, TiO2, Al2O3, Fe2O3, FeO, MnO, MgO, CaO, Na2O, K2O, P2O5, SO3, CO2, H2O used in amounts of at least one gram per liter of the volume of the treated equipment. Circulation of the solution is accomplished at the temperature of the working condition of the equipment, and the scale is removed by blow-through by water or steam at least after 72 hours of solution circulation at the following relation of the oxides of elements contains in the composition, percent by mass

EFFECT: enhanced efficiency of equipment cleaning in service and formation of a protective film on the heating surfaces preventing the repetitive scale formation thus increasing the overhaul period.

FIELD: heat power engineering.

SUBSTANCE: invention relates to prestarting chemical cleaning and passivating of equipment surfaces and it can be used for prestarting cleaning of heating surfaces of recovery boilers of steam-gas plants from inner deposits and cleaning of other boilers. Method includes washing of surfaces to be cleaned by survice water in open circuit, creating of at least one closed circuit including at least part of surface to be cleaned and provision of circulation of heated solution of chemical reagent in said closed circuit. Solution of reagent is prepared directly in each circuit by filling the circuit with desalinated or softened water with subsequent introduction of reagent. Water solution of mixture of volatile and film forming amines mixed with dispersing agent is used as reagent. Solution is heated to 70-350°C. Reagent is added at a rate of 5-25 g/sq.m to saturated surface of circuits revealed by appearance of concentration of reagent in solution within 25 mg/l. When content of ferrum compounds in circulating solution equals 10 mg/l. blowing through of circuits is started with introduction into circuits of make-up water and reagent. Cleaning is carried out for at least 24 h until concentration of ferrum compounds in circulating solution of reagent is reduced by 1/l, minimum.

EFFECT: simplified and reduced cost of cleaning, preventing of discharge of substances harmful to environment.

1 ex

FIELD: heat supply systems.

SUBSTANCE: method comprises supplying pulses of pressurized air and discharging contaminated liquid. The heating apparatus to be cleaned is connected with the air hydraulic pulse unit through flexible hose. The compressed air pulses are generated in the air receiver by means of gradual opening of the valve that is spring-loaded and has varying area of the cross-section. As a result, the expanding air is intensively mixed with water thus removing contaminations from the surface of heating apparatus.

EFFECT: enhanced efficiency and reliability.

3 dwg

FIELD: nuclear and thermal power engineering, possible use for restoring serviceability of steam generators and other thermal power engineering equipment by means of chemical washing.

SUBSTANCE: method includes sequential three-stage processing of working surfaces of steam-water hollow of steam generator by water solutions in forced stirring mode, at which during first and third stages ammoniac solution of ammonium salt of weak organic acid is used with concentration of 5-50 g/kg and hydrogen peroxide with 1-5 g/kg concentration, and at second stage a solution is used consisting of ethylene diamine tetra-acetic acid, ammonium salt of weak organic acid and hydrazine with weight ratio of components 1:0,65:0,1, respectively. After draining of solutions used during first and third washing stages, regeneration of solutions is performed by precipitating hydroxide or oxide of copper in them, dividing the sediment and growth solution and injecting admixtures into growth solution and then returning regenerated solutions into washing cycle of other steam generators of power unit.

EFFECT: decreased volumes of liquid toxic wasters and energy costs required for their reprocessing; decreased flow of distillate required for performing power unit steam generator washing operations; decreased probability of migration of copper into natural waters in the region near a nuclear power plant.

6 cl, 5 tbl

FIELD: heat engineering, possible use for steam-chemical cleaning of internal surfaces of boiler pipes from precipitations of both operational (salt) and atmospheric corrosion (ferrioxide) products.

SUBSTANCE: method includes blowing surfaces being cleaned with overheated steam with dosed injection of chemical reagent into steam. As chemical reagent, water solutions of complexions are used at concentration in steam-chemical environment ranging from 0,1 to 5,0% of mass, and cleaning is performed under steam pressure 0,2-0,7 MPa and temperature of boiler pipe surface heating in interval of 130-170°C.

EFFECT: increased efficiency of cleaning.

3 cl, 1 dwg, 3 app

FIELD: the invention refers to servicing and repairing of the heating systems of inhabited and industrial premises, and also of boiler plants and central heating points.

SUBSTANCE: the installation for chemical cleaning of heating systems has a foundation, on which there are installed a low pressure and a high pressure pumps. Each pump is placed vertically and is set in motion with a separate electric engine. The pumps are located at a distance from each other and in the space between them there is installed a disperser in the shape of a vertical tubular capacity with a hopper in the lid for filling the capacity with liquid chemical reagent. The capacity is connected with the pumps and the radiators of the central heating. In the capacity there are installed splitters of the flow of fluid medium in the shape of cases with pointed edges and of rods with pointed ends.

EFFECT: such fulfillment of the installation simplifies its construction, increases reliability and safety of the operators' work.

2 dwg

FIELD: clearing of heat exchangers from asphalt-resin-wax deposits (ARWD), applicable in oil production.

SUBSTANCE: the method consists in the fact that a system of connection of the elements in the operating condition is made, that has a system of supply of cold crude oil from the wells, heat recuperation unit (HRU), system of discharge of crude heated oil from the HRU to the terminal separation plant (TSP) of crude oil, preliminary water discharge reservoir (WDR), desalting and dehydration plant (DDP) for commercial oil, system for delivery of hot finished separated oil from the TSP to the commercial oil reservoir. Cold crude oil from the wells is directed to the HRU, heated in the HRU is the cold crude oil by means of the exchange with the flow of hot finished separated oil. The hot finished separated oil is cooled down by heat exchange with the flow of cold crude oil. Monitoring of the temperature of the heated and cooled oil is accomplished, monitoring of the liquid level in the bullets of the commercial oil TSP is performed. Use is made of the clearing condition that consists in the fact that the flow of cold crude oil is completely overlapped, hot finished separated oil at a temperature 41 to 43 C is supplied, the ARWD is heated and diluted by the flow of hot finished separated oil; the ARWD is discharged from the ducts of hot finished separated oil by the same flow supplied to the HRP in the clearing condition at a speed making up 5 to 30 per cent of the speed of this flow in the operating condition, then the heated and diluted ARWD accumulated in the clearing condition is discharged from the ducts that are used for passage of the flow of cold crude oil by the same flow in the operating position.

EFFECT: reduced net cost of oil.

2 cl, 1 dwg

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