A method for blowing and cleaning scale of a converter waste heat boiler

Abstract

The application discloses a kind of converter waste heat boiler scale blowing cleaning method, the method comprises the following steps: S1, after the end of the maintenance furnace base converter item repair, the corresponding waste heat boiler is boiled, closes the steam regulating valve (3) of the steam drum (1) outside sending to regenerator, opens steam drum (1) steam is dispersed by dispersing valve (2);S2, close dispersing valve (2) after the water temperature of steam drum (1) is reduced to 100 degrees;S3, using gas welding to open mobile section flue blowout hole (17) of mobile section lower annular tube, open fixed first section flue blowout hole (22) of fixed first section flue lower annular tube, open fixed second section flue blowout hole (23) of fixed second section flue lower annular tube, open fixed third section flue blowout hole (11) of fixed third section flue lower annular tube;S4, close the inlet electric valve (19) of two middle pressure pumps (20) of middle pressure forced circulation, outlet electric valve (21);S5, open the steam regulating valve (3) of the steam drum (1) outside sending to regenerator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of converter waste heat boiler, in particular to a converter waste heat boiler scale blowing and cleaning method. BACKGROUND

[0002] The converter waste heat boiler is an important part of the converter production equipment, and mainly cools the flue gas generated during the converter smelting and produces steam by using the waste heat of the flue gas. The safe and stable operation of the converter waste heat boiler is one of the important conditions for ensuring the stable and smooth production of the converter.

[0003] The moving section flue of the converter waste heat boiler adopts forced circulation under medium pressure, and the fixed first section, the fixed second section and the fixed third section flues adopt natural circulation. The converter waste heat boiler system mainly uses soft water circulation. Since there are Mg 2+ , Ca 2+ and weak acid ions in the soft water, as the waste heat boiler water evaporates continuously, when the calcium and magnesium ions in the boiler water reach saturation, solid substances are precipitated. If the precipitated solid substances are suspended in the water, they are called water slag, and if they are firmly attached to the heating surface, they are called scale. Scale is the source of 100 harms of the waste heat boiler. The scale on the pipe wall of the waste heat boiler flue will cause the pipe wall temperature to rise due to the increase in thermal resistance, the pressure bearing capacity will decrease, and transverse cracks, longitudinal cracks and bulges will occur on the pipe wall. When the scale is serious, it can block the flue circulating water pipeline, causing the waste heat boiler flue to burst, and then causing serious accidents such as shutdown and explosion. Especially during the converter repair period, the repair furnace seat steam drum and the waste heat boiler circulating water are all emptied, at this time the waste heat boiler flue is at room temperature, and the circulating water temperature in the waste heat boiler can reach 200 degrees during the converter smelting period. Due to the thermal expansion and cold contraction phenomenon, the scale on the inner wall of the waste heat boiler flue pipe cracks, loosens and falls off, and the scale accumulation causes internal blockage of the flue pipe, poor water flow, and thus causes flue pipe burst and water leakage accidents. The current measures to prevent scale formation still have scale in the pipeline after implementation. Since scale cannot be completely avoided, a method is needed to conveniently and quickly, simply and efficiently clean the scale in the pipeline to enable the equipment to operate normally. SUMMARY

[0004] In view of the above technical problems, the present application provides a converter waste heat boiler scale blowing and cleaning method.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] A converter waste heat boiler scale blowing and cleaning method, comprising the following steps:

[0007] S1. After the overhaul of the converter at the furnace seat is completed and the corresponding waste heat boiler is boiled, close the steam regulating valve for the steam drum to the accumulator and open the steam drum venting valve to release the steam from the steam drum.

[0008] S2. After the water temperature of the steam drum drops to 100 degrees, close the vent valve and open the steam drum drain valve, the moving section flue drain valve, the fixed first section flue drain valve, the fixed second section flue drain valve, and the fixed third section flue drain valve to drain water from the steam drum and the moving section, fixed first section, fixed second section, and fixed third section flues. After draining the water, close the drain valves of the waste heat boiler flue and the steam drum.

[0009] S3. Use gas welding to open the flue gas purging hole of the moving section lower ring pipe, open the flue gas purging hole of the fixed section lower ring pipe, open the flue gas purging hole of the fixed section lower ring pipe, open the flue gas purging hole of the fixed section lower ring pipe, open the flue gas purging hole of the fixed section lower ring pipe, and open the flue gas purging hole of the fixed section lower ring pipe, and weld protective plates around the purging holes.

[0010] S4. Close the inlet and outlet electric valves of the two medium-pressure pumps for forced circulation.

[0011] S5. Set the pressure of the main steam regulating valve for the heat accumulator to the company's external network to 1.2 MPa. Once the pressure of the three heat accumulators and other waste heat boiler systems rises to 1.2 MPa, the conditions for steam purging of scale in the waste heat boilers are met. When the pressure of the three heat accumulators and other waste heat boiler systems rises to 1.2 MPa, open the steam regulating valve for the heat accumulators. At this time, steam flows back from the heat accumulators and other waste heat boiler systems to the steam drum through the steam delivery pipe, and then flows from the steam drum riser pipe and downcomer pipe to the moving section flue, the fixed section flue, the fixed section flue, and the lower ring pipe of the fixed section flue. Finally, it is blown out from the purging holes of the moving section flue, the fixed section flue, the fixed section flue, and the fixed section flue, simultaneously blowing out the scale in the waste heat boilers, thereby achieving the purpose of cleaning the scale in the converter waste heat boilers.

[0012] In step S3, the dimensions of the moving section flue purging hole, the fixed first section flue purging hole, the fixed second section flue purging hole, and the fixed third section flue purging hole are 150mm × 150mm.

[0013] In step S5, when opening the steam regulating valve of the heat accumulator, the opening degree needs to be gradually increased from 0% to 100%.

[0014] In step S5, after cleaning, the moving section flue purge hole is sealed, the first section flue purge hole is fixed, the second section flue purge hole is fixed, and the third section flue purge hole is fixed. The inlet electric valve and outlet electric valve of the two medium-pressure pumps are opened, and the filters of the two medium-pressure pumps are opened for cleaning. After cleaning, the medium-pressure pump filter 18 is reinstalled.

[0015] The beneficial effects of this invention are:

[0016] 1. It solves the problem of difficult-to-clean scale inside the waste heat boiler flue, improves the service life of the waste heat boiler flue, and reduces equipment maintenance costs.

[0017] 2. This method can be used to easily and quickly clean the scale inside the waste heat boiler.

[0018] 3. This method does not require the use of other auxiliary cleaning agents, does not increase costs, has no side effects on waste heat boilers, and can quickly and effectively clean the scale inside waste heat boilers. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an existing single-furnace converter waste heat boiler system.

[0020] Figure 2 This is a schematic diagram of an existing heat storage system.

[0021] The diagram shows: 1. Steam drum, 2. Steam drum vent valve, 3. Regenerator steam regulating valve, 4. Safety valve, 5. Steam drum water supply valve, 6. Steam drum pressure gauge, 7. Steam drum blowdown valve, 8. Explosion-proof door, 9. Fixed three-section flue, 10. Fixed three-section flue blowdown valve, 11. Fixed three-section flue purge port, 12. Fixed two-section flue blowdown valve, 13. Fixed one-section flue blowdown valve, 14. Fixed one-section flue, 15. Mobile flue blowdown valve, 16. Mobile flue, 17. Mobile flue. 18. Purge port; 19. Medium-pressure pump filter; 20. Medium-pressure pump inlet electric valve; 21. Medium-pressure pump outlet electric valve; 22. Fixed first-stage flue purge port; 23. Fixed second-stage flue purge port; 24. Fixed second-stage flue; 30. Heat accumulator; 31. Heat accumulator pressure gauge; 32. Heat accumulator vent valve; 33. Silencer; 34. Heat accumulator steam external supply regulating valve; 35. Heat accumulator external supply shut-off valve; 36. Heat accumulator steam external supply regulating main valve; 37. Heat accumulator drain valve. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0023] like Figure 1 and Figure 2 As shown, a method for cleaning scale in a converter waste heat boiler includes the following steps:

[0024] S1. After the overhaul of the converter at the furnace seat is completed and the corresponding waste heat boiler is boiled, the steam regulating valve 3 for the steam drum 1 to the accumulator is closed, and the steam drum venting valve 2 is opened to vent the steam in the steam drum 1.

[0025] S2. After the water temperature of steam drum 1 drops to 100 degrees, close the vent valve 2 and open the steam drum drain valve 7, the moving section flue drain valve 15, the fixed first section flue drain valve 13, the fixed second section flue drain valve 12, and the fixed third section flue drain valve 10 to drain water from steam drum 1 and the moving section, fixed first section, fixed second section, and fixed third section flues. After draining the water, close the drain valves of the waste heat boiler flue and steam drum.

[0026] S3. Use gas welding to open the flue gas purging hole 17 of the moving section lower ring pipe, open the flue gas purging hole 22 of the fixed section lower ring pipe, open the flue gas purging hole 23 of the fixed section lower ring pipe, open the flue gas purging hole 11 of the fixed section lower ring pipe, and weld protective plates around the purging holes.

[0027] S4. Close the inlet electric valve 19 and outlet electric valve 21 of the two medium-pressure forced circulation pumps 20;

[0028] S5. Set the pressure of the external steam regulating valve 36 of the heat accumulator to 1.2 MPa. After the pressure of the three heat accumulators 30 and other waste heat boiler systems rises to 1.2 MPa, the conditions for steam purging of scale in the waste heat boilers are met. When the pressure of the three heat accumulators 30 and other waste heat boiler systems rises to 1.2 MPa, open the steam regulating valve 3 of the steam drum 1 to the heat accumulator. At this time, steam flows from the heat accumulators 30 and other waste heat boilers... The boiler system returns steam to the steam drum 1 through the steam drum steam delivery pipe, and flows from the steam drum riser pipe and downcomer pipe to the moving section flue 16, the fixed first section flue 14, the fixed second section flue 24, the fixed third section flue 9 lower ring pipe, and finally blows out from the moving section flue purging hole 17, the fixed first section flue purging hole 22, the fixed second section flue purging hole 23, and the fixed third section flue purging hole 11, while simultaneously blowing out the scale from the waste heat boiler, thereby achieving the purpose of cleaning the scale from the converter waste heat boiler.

[0029] In step S3, the dimensions of the movable section flue purging hole 17, the fixed section flue purging hole 22, the fixed second section flue purging hole 23, and the fixed third section flue purging hole 11 are 150mm × 150mm.

[0030] In step S5, when opening the accumulator steam regulating valve 3, the opening degree needs to be gradually increased from 0% to 100%.

[0031] In step S5, after cleaning, the moving section flue purge hole 17 is sealed, the first section flue purge hole 22 is fixed, the second section flue purge hole 23 is fixed, and the third section flue purge hole 11 is fixed. The inlet electric valve 19 and outlet electric valve 21 of the two medium-pressure pumps 20 are opened, and the two medium-pressure pump filters 18 are opened for cleaning. After cleaning, the medium-pressure pump filters 18 are reinstalled.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for cleaning scale from a converter waste heat boiler, characterized in that, Includes the following steps: S1. After the overhaul of the converter at the furnace seat is completed and the corresponding waste heat boiler is boiled, close the steam drum (1) and send the steam to the accumulator steam regulating valve (3), and open the steam drum venting valve (2) to release the steam from the steam drum (1). S2. After the water temperature of the steam drum (1) drops to 100 degrees, close the vent valve (2), open the steam drum drain valve (7), the moving section flue drain valve (15), the fixed section flue drain valve (13), the fixed section flue drain valve (12), and the fixed section flue drain valve (10) to drain water from the steam drum (1) and the moving section, fixed section, fixed section, and fixed section flues. After draining the water, close the drain valves of the waste heat boiler flue and the steam drum. S3. Use gas welding to open the flue gas purging hole (17) on the lower ring pipe of the moving section, open the flue gas purging hole (22) on the lower ring pipe of the fixed section, open the flue gas purging hole (23) on the lower ring pipe of the fixed section, open the flue gas purging hole (11) at the lower ring pipe of the fixed section, and weld protective plates around the purging holes. S4. Close the inlet electric valve (19) and outlet electric valve (21) of the two medium-pressure forced circulation pumps (20); S5. Set the pressure of the steam regulating valve (36) of the external network of the heat accumulator to 1.2 MPa. After the pressure of the three heat accumulators (30) and other waste heat boiler systems rises to 1.2 MPa, the conditions for steam purging of scale in the waste heat boilers are met. When the pressure of the three heat accumulators (30) and other waste heat boiler systems rises to 1.2 MPa, open the steam drum (1) to send steam to the heat accumulator steam regulating valve (3). At this time, steam flows from the heat accumulators (30) and other waste heat boiler systems. Steam flows back to the steam drum (1) through the steam drum external pipe, and flows from the steam drum riser pipe and downpipe to the moving section flue (16), the fixed section flue (14), the fixed section flue (24), the fixed section flue (9) and the lower ring pipe. Finally, it is blown out from the moving section flue purging hole (17), the fixed section flue purging hole (22), the fixed section flue purging hole (23), and the fixed section flue purging hole (11), which at the same time drives the waste heat boiler scale to be blown out, thereby achieving the purpose of cleaning the scale of the converter waste heat boiler.

2. The method for cleaning scale from a converter waste heat boiler according to claim 1, characterized in that, In step S3, the dimensions of the movable section flue purging hole (17), the fixed section flue purging hole (22), the fixed second section flue purging hole (23), and the fixed third section flue purging hole (11) are 150mm×150mm.

3. The method for cleaning scale from a converter waste heat boiler according to claim 1, characterized in that, In step S5, when opening the accumulator steam regulating valve (3), the opening degree needs to be gradually increased from 0% to 100%.

4. The method for cleaning scale from a converter waste heat boiler according to claim 1, characterized in that, In step S5, after cleaning is completed, the moving section flue purge hole (17), the fixed section flue purge hole (22), the fixed second section flue purge hole (23), and the fixed third section flue purge hole (11) are sealed. The inlet electric valve (19) and outlet electric valve (21) of the two medium-pressure pumps (20) are opened. The two medium-pressure pump filters (18) are opened for cleaning. After cleaning is completed, the medium-pressure pump filters (18) are reinstalled.

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