Slag-bonding and nodulation-preventing converting furnace system

Abstract

An anti-slagging and anti-nodulation converting furnace system comprises a flash converting furnace (1) and a waste heat boiler (2), the flash converting furnace (1) is composed of a reaction tower (3), a sedimentation tank (4) and an exhaust flue (5), and the converting furnace system is characterized in that a slag blocking plate (6), a slag blocking sieve (7) and a water cooling hanging screen (8) are sequentially arranged in the exhaust flue from bottom to top; the water-cooling hanging screen (8) comprises a plurality of groups of heat exchange tubes (81) which are vertically arranged; wherein the surfaces of the slag blocking plate (6), the slag blocking sieve (7), a heat exchange pipe (81) of the water-cooling hanging screen (8) and the exhaust flue furnace lining (51) are coated with composite crystal films. According to the converting furnace system disclosed by the utility model, about 85% of fusible particles can be blocked or gathered in the exhaust flue, and are vibrated by the dust removal device to fall into slag. Over-temperature and pipe explosion accidents of the waste heat boiler are prevented, and long-period safe and stable operation of the flash furnace and the waste heat boiler is guaranteed.

Description

Technical Field

[0001] The utility model generally relates to metallurgical equipment, belongs to the technical field of energy saving in the copper smelting industry, and specifically relates to a slagging and nodulation-resistant blowing furnace system. Background Art

[0002] Flash converting furnaces have been widely used in nonferrous smelting enterprises. The smelting temperature of flash furnaces is high, and the high-temperature flue gas produced is recycled by waste heat boilers. The overall thermal efficiency of the converting furnace is high, and it is energy-saving, emission-reducing and environmentally friendly. The temperature of the high-temperature flue gas in the ascending flue and the air inlet area of ​​the waste heat boiler reaches about 1100°C, and the smoke rate reaches 6-10%. There are many fusible particles in the flue gas, which are easy to form slag and nodules on the refractory lining in various areas of the furnace. The vibrating plate of the concentrate nozzle is specially designed to prevent nodules around the nozzle, but it is effective in the short term, and the nodule problem still exists for a long time. It is necessary to manually remove the nodules on the vibrating plate with an iron rod. In addition, the high-temperature flue gas carries particles into the waste heat boiler, and the boiler slag plate, water-cooled wall, and heat exchange tube bundle are bonded to form coking, slag, and nodules, which will cause accidents such as overheating of the water-cooled wall and bursting of the tube. The continuous operation time of the device is short, and there are safety hazards.

[0003] At present, the flash furnace's concentrate nozzle vibration plate still needs to be manually temporarily de-nozzled, which is dangerous. The waste heat boiler is equipped with slag baffles, ash hoppers, blasting dust removal devices and other devices at the rear end of the air inlet flue to remove slag and nodules. Since the slag baffle is in a high temperature and corrosive environment, the slag, nodules and slag baffles have a high bonding strength, making it difficult to remove. In addition, the amount of slag and nodules is large, and large pieces of slag are easily dropped during the slag and nodule removal process to damage the equipment. Utility Model Content

[0004] In view of the current dust and slag removal problems in high-temperature flue gas of flash converting furnaces, as well as the slagging and nodulation problems on the slag baffles, water-cooled walls, and heat exchange tube bundles of waste heat boilers, the utility model provides a converting furnace system with anti-slagging and nodulation properties. The dust and slag removal solutions designed according to the characteristics of the flue gas and the structure of the converting furnace can reduce the smoke particles in the flue gas, improve the heat exchange effect of the waste heat boiler, extend the stable operation time of the device, and improve the safety of the device.

[0005] According to the utility model, a slagging and nodulation-resistant refining furnace system (or device) includes a flash refining furnace and a waste heat boiler. The flash refining furnace consists of three parts: a reaction tower, a sedimentation tank and an exhaust flue, wherein the reaction tower and the exhaust flue are respectively arranged on the upper left and right sides of the sedimentation tank; the exhaust flue outlet is connected to the waste heat boiler; slag retaining plates, slag retaining screens and water-cooled hanging screens are sequentially arranged in the exhaust flue from bottom to top; the water-cooled hanging screen comprises multiple groups of vertically arranged heat exchange tubes; wherein the surfaces of the slag retaining plates, slag retaining screens, heat exchange tubes of the water-cooled hanging screens and the exhaust flue lining are coated with a composite crystal film (coating).

[0006] In specific cases, the slag retaining plate, the slag retaining screen and the water-cooled hanging screen are respectively provided with a vibrating ash remover.

[0007] Specifically, the slag retaining plate is surrounded by steel plates of a "U-shaped" funnel structure, and the four side steel plates are at ∠45° with the exhaust flue. Preferably, the sum of the vertical projection areas of the four side steel plates of the slag retaining plate is 25% of the cross-sectional area of ​​the exhaust flue.

[0008] Preferably, the screen holes of the slag retaining screen are square holes with a side length of 100-150 mm.

[0009] Specifically, a concentrate nozzle is arranged at the center of the top of the reaction tower, and a hot air pipeline, a concentrate pipeline and a heavy oil pipeline are arranged above the concentrate nozzle; a vibration plate is arranged below the concentrate nozzle, and the surface of the vibration plate is coated with a composite crystal film.

[0010] Preferably, the vertical lengths of the multiple groups of heat exchange tubes of the water-cooled hanging screen gradually decrease along the flue gas flow direction.

[0011] The technical principle of preventing slagging and nodulation in the blowing furnace system of the utility model:

[0012] 1. The flue gas from the blowing furnace is easy to form slag and nodules on the metal and furnace lining surface, and it is difficult to clean because:

[0013] (1) The molten alkali metals and low-melting-point particles in the flue gas adhere to the heated surface at high temperatures, gradually forming slag and nodules.

[0014] (2) Molten alkali metals will corrode the heated surface, so that the slag, nodules and substrate form a high-strength bond, so the coke and nodules are difficult to clean.

[0015] Therefore, the composite crystal membrane with outstanding high temperature corrosion resistance and anti-coking and slagging performance used in furnace lining, slag baffle plate, and hanging screen heat exchange tube will not adhere to coking and slagging, nor will it be corroded by them. The composite crystal membrane has the characteristics of low surface energy, and it is difficult for molten particles to adhere to its surface, so it is not easy to produce slagging and nodules. The composite crystal membrane is chemically inert, does not react with smoke, and is not corroded, so it is not difficult to clean.

[0016] The composite crystal film applied on the surface of the slag screen has excellent anti-corrosion effect. The molten particles will adhere to its surface, but will not form a high-strength bond, so the slag and nodules are easy to clean using a vibrating dust collector. The slag screen plays the role of capturing and removing smoke particles.

[0017] 2. The slag plate directly blocks the smoke and dust particles close to the furnace wall below the slag plate, and only a small amount of accumulation is formed at the angle between the slag plate and the furnace lining. The vibrator can be used to remove ash and slag regularly, and the ash and slag directly fall into the molten pool for waste discharge. Therefore, the slag plate effectively prevents smoke and dust from approaching and adhering to the furnace wall, and the furnace wall can remain clean for a long time.

[0018] 3. The water-cooled hanging screen can initially reduce the flue gas temperature, solidify the low-melting-point particles in the flue gas, and will not adhere to the hanging screen heat exchange tube with the composite crystal film. Some particles will be blocked outside the air inlet of the waste heat boiler in solid form, and eventually fall into the sedimentation tank and be discharged with the slag. The other part will follow the flue gas into the waste heat boiler, be intercepted at the waste heat boiler slag blocking device and fall into the boiler ash hopper. The water-cooled hanging screen further reduces the smoke particles in the flue gas.

[0019] Compared with the existing devices, the device of the utility model has the following advantages:

[0020] 1. Compared with the original device, the flue slag baffle and water-cooled hanging screen are added, and the composite crystal film with high temperature corrosion resistance and anti-coking and slagging is applied on its surface, which can easily vibrate the coke and slag adhered on the surface and drop them into the molten slag without aggregation and difficulty in removal. 85% of the smoke dust is removed in the flue, which can ensure the efficient and stable operation of the waste heat boiler.

[0021] 2. Compared with the original device, a flue slag screen is added. The surface of the screen is a composite crystal film resistant to high temperature corrosion, but the surface energy is similar to that of metal, which can capture smoke and molten particles. The smoke and molten particles adhere to the slag screen, and the slag is knocked off by the vibrating dust collector to achieve the purpose of dust removal.

[0022] 3. The vibrating plate is surface treated with a composite crystal film, which can effectively and long-term prevent nodules at the nozzle outlet, avoiding the dangerous operation of manual coke removal and nodules.

[0023] 4. The original slag retaining device in the waste heat boiler is used to retain slag, where a large amount of coking and nodules will form, requiring regular shutdown for cleaning, and during the cleaning process, large coke blocks will fall and damage the furnace body. After the modification of the utility model, the smoke rate of flue gas entering the waste heat boiler is reduced by 85%, which can reduce the slag retaining device in the waste heat boiler due to slag nodules and reduce the number of shutdowns for coking. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of a blowing furnace system for preventing slagging and nodulation according to the utility model;

[0025] Figure 2 It is a three-dimensional schematic diagram of the setting state of the slag retaining plate in the utility model;

[0026] Figure 3 It is a schematic diagram of the setting state of the slag baffle plate and the vibration dust collector in the utility model;

[0027] Figure 4 It is a three-dimensional schematic diagram of the setting state of the slag retaining screen in the utility model;

[0028] Figure 5It is a schematic diagram of the setting state of the slag screen and the vibration dust collector in the utility model;

[0029] Figure 6 It is a side view schematic diagram of the water-cooled hanging screen structure in the utility model;

[0030] Wherein, each reference numeral represents:

[0031] 1-flash refining furnace, 2-waste heat boiler, 3-reaction tower, 4-sedimentation tank, 41-slag outlet, 5-exhaust flue, 51-furnace lining, 6-slag retaining plate, 61-steel plate, 7-slag retaining screen, 8-water cooling hanging screen, 81-heat exchange tube, 82-water inlet, 83-water return outlet, 84-collecting pipe, 9-vibrating dust collector, 91-vibrating head, 10-concentrate nozzle, 101-hot air duct, 102-concentrate duct, 103-heavy oil duct, 104-vibrating plate, 11-fixing parts. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be understood by those skilled in the art that the embodiments described below are merely exemplary descriptions of the present invention and are not intended to limit the present invention in any way.

[0033] Figure 1 A specific embodiment of the utility model is shown, and the slagging and nodulation-proof converting furnace system includes a flash converting furnace 1 and a waste heat boiler 2. The flash converting furnace 1 consists of three parts: a reaction tower 3, a sedimentation tank 4, and an exhaust flue 5, wherein the reaction tower 3 is arranged at the upper left part of the sedimentation tank 4, and the exhaust flue is arranged at the upper right part of the sedimentation tank 4. The outlet of the exhaust flue 5 is connected to the waste heat boiler 2, and a slag retaining plate 6, a slag retaining screen 7, and a water-cooled hanging screen 8 are sequentially arranged in the exhaust flue 5 from bottom to top. The slag retaining plate 6, the slag retaining screen 7, and the water-cooled hanging screen 8 are respectively provided with a vibrating ash remover 9.

[0034] A concentrate nozzle 10 is arranged at the center of the top of the reaction tower 3, and a hot air pipeline 101, a concentrate pipeline 102 and a heavy oil pipeline 103 are arranged on the upper part of the concentrate nozzle 10; a vibration plate 104 is arranged at the lower part of the concentrate nozzle 10. The concentrate powder is melted into liquid after high-temperature reaction in the reaction tower 3 and enters the sedimentation tank 4. The flue gas after combustion first enters the exhaust flue 5 and then enters the waste heat boiler 2.

[0035] See Figure 2-3The slag retaining plate 6 is formed by arranging four side steel plates 61, which are fixed to the four side furnace linings 51 through fixing parts 11, presenting a "Hui-shaped" funnel structure. The four side steel plates 61 are ∠45° with the air inlet flue, and the middle is a flue gas channel. The size of the slag retaining plate 6 is designed according to the actual flue gas volume. If the slag retaining plate 6 is too long, it will hinder the normal discharge of flue gas; if the slag retaining plate 6 is too short, the slag retaining effect is not ideal; the sum of the vertical projection areas of the four side steel plates 61 of the slag retaining plate is 25% of the cross-sectional area of ​​the exhaust flue 5, which is the best. The motor of the rapping ash remover 9 matched with the slag retaining plate 6 is set outside the exhaust flue 5, and the rapping head 91 is set at the bottom of the steel plate 61. After the system is running, the rapping ash remover 9 starts the rapping head 91 at a certain time interval to rap the slag retaining plate 6, clean the surface ash into the sedimentation tank 4 below, and discharge it outward through the slag port 41 together with the slag.

[0036] See Figure 4-5 The slag screen 7 is arranged above the slag plate 6, and is also fixed to the furnace lining 51 of the exhaust flue 5 by the fixing part 11, and a rapping dust collector 9 is provided accordingly, and the rapping head 91 is arranged below the slag screen. The slag screen 7 can further capture the smoke and molten particles, and the smoke and molten particles adhere to the slag screen 7, and the slag is knocked off by the rapping dust collector 9 to achieve the purpose of dust removal. The aperture design of the slag screen 7 needs to be determined by experiments. If the aperture is too large, the effect of blocking the adhering smoke particles becomes poor, and if it is too small, it is easy to cause blockage and affect the smoke flow. A more reasonable one is a square hole with a side length of 100-150mm.

[0037] See Figure 1 and Figure 6 The water-cooled hanging screen 8 comprises a plurality of groups of heat exchange tubes 81 arranged vertically, and the vertical lengths of the plurality of heat exchange tubes 81 gradually decrease along the flue gas flow direction. The water inlet and water outlet of the plurality of heat exchange tubes 81 are connected to the water inlet 82 and the water return port 83 through the manifold 84 respectively. Each group of heat exchange tubes 81 is correspondingly provided with a vibration dust collector 9.

[0038] In the blowing furnace system of the utility model, the surfaces of the slag retaining plate 6, the slag retaining screen 7, the heat exchange tube 81 of the water-cooled hanging screen 8, the furnace lining 51 of the exhaust flue 5, and the vibrating plate 104 of the concentrate nozzle 10 are coated with a composite crystal film. The thickness of the composite crystal film on the furnace lining 51 is 100-200μm. The thickness of the composite crystal film applied to the vibrating plate 104, the slag retaining plate 6, the slag retaining screen 7, and the water-cooled hanging screen 8 is 60-100μm, and all composite crystal films should have a complete and smooth appearance. The composite crystal film has the characteristics of low surface energy, and it is difficult for molten particles to adhere to its surface, so it is not easy to produce slag and nodules. The composite crystal film is chemically inert, does not react with smoke, and is not corroded, so there is no situation that is difficult to clean.

[0039] The fixing member 11 mentioned in the above embodiment can be a conventional fixing member such as a bolt, and the composite crystal membrane is made of SEC-E series materials produced by Beijing Xike Energy Saving and Environmental Protection Technology Co., Ltd.

[0040] When the blowing furnace system of the utility model is in operation, the smoke dust particle removal process in the flue gas is as follows:

[0041] High-temperature flue gas is generated in the reaction tower 3 and the sedimentation tank 4 and enters the waste heat boiler 2 through the exhaust flue 5 .

[0042] 1. The smoke first encounters the slag blocking plate 6 in the exhaust flue 5, which blocks the smoke particles in the smoke close to the furnace lining 51. The subsequent contact of the furnace lining 51 with the smoke particles is greatly reduced, which reduces the slagging of the furnace lining. The smoke particles adhering to the slag blocking plate 6 are vibrated and dropped by the vibrating dust collector 9.

[0043] 2. The flue gas continues to rise and passes through the slag screen 7, where the "screen" further adheres to the smoke particles, achieving the purpose of dust and slag removal. The smoke particles adhered to the slag screen 7 are vibrated and dropped by the vibrating dust collector 9.

[0044] 3. The flue gas continues to rise and passes through the water-cooled hanging screen 8, where the heat of the flue gas is absorbed by the water in the water-cooled hanging screen heat exchange tube 81, the flue gas temperature decreases, the smoke dust particles cool and solidify and lose their adhesion, a part of them falls into the sedimentation tank 4 and is discharged, and the other part enters the waste heat boiler 2 with the flue gas. Since the adhesion of the smoke dust particles is reduced, they will not stick to the boiler slag retaining plate when encountering the waste heat boiler slag retaining plate, and will eventually fall into the boiler ash hopper.

[0045] After research and investigation of actual working conditions, the exhaust flue is the best area to remove smoke particles in the flue gas. The smoke particles can fall into the slag and be discharged from the flash refining furnace from the slag port along with the slag. Due to the high temperature and corrosive environment of the exhaust flue, there are currently no measures to remove smoke particles. This device uses high temperature resistant metal materials to make vibration plates, slag retaining plates, slag retaining screens, water-cooled hanging screen heat exchange tubes, etc., and uses composite crystal membrane technology for surface treatment to improve surface corrosion resistance and reduce surface energy. After slagging and nodules, it is easy to vibrate and clean, and the smoke particles in the high-temperature flue gas can be intercepted and removed in the exhaust flue. The flow of smoke particles to the inside of the waste heat boiler is reduced, the stable operation cycle of the device is extended, and the number of boiler cleaning times is reduced by 3 to 4 times.

[0046] The above are only preferred embodiments of the present invention. Any equivalent changes or modifications made according to the claims of the present invention shall fall within the scope of the claims of the present invention.

Claims

1. A converting furnace system for preventing slagging and nodulation, comprising a flash converting furnace (1) and a waste heat boiler (2), wherein the flash converting furnace (1) consists of three parts: a reaction tower (3), a sedimentation tank (4) and an exhaust flue (5), wherein the reaction tower (3) and the exhaust flue (5) are respectively arranged on the upper left and right sides of the sedimentation tank (4); the outlet of the exhaust flue (5) is connected to the waste heat boiler (2); characterized in that: A slag retaining plate (6), a slag retaining screen (7) and a water-cooled hanging screen (8) are arranged in sequence from bottom to top in the exhaust flue; the water-cooled hanging screen (8) comprises a plurality of groups of heat exchange tubes (81) arranged vertically; wherein the surfaces of the slag retaining plate (6), the slag retaining screen (7), the heat exchange tubes (81) of the water-cooled hanging screen (8) and the exhaust flue furnace lining (51) are coated with a composite crystal film.

2. The blowing furnace system according to claim 1, characterized in that: The slag retaining plate (6), the slag retaining screen (7) and the water-cooling hanging screen (8) are respectively provided with a vibrating ash remover (9).

3. The blowing furnace system according to claim 1, characterized in that: The slag retaining plate (6) is surrounded by a steel plate (61) of a "U-shaped" funnel structure, and the four side steel plates (61) are at an angle of ∠45° to the exhaust flue (5).

4. The converting furnace system according to claim 3, characterized in that: The sum of the vertical projection areas of the steel plates (61) on the four sides of the slag retaining plate is 25% of the cross-sectional area of ​​the exhaust flue (5).

5. The blowing furnace system according to claim 1, characterized in that: The sieve holes of the slag retaining screen (7) are square holes with a side length of 100-150 mm.

6. The converting furnace system according to claim 1, characterized in that: A concentrate nozzle (10) is arranged at the center of the top of the reaction tower (3), and a hot air pipeline (101), a concentrate pipeline (102) and a heavy oil pipeline (103) are arranged on the upper part of the concentrate nozzle (10); a vibration plate (104) is arranged at the lower part of the concentrate nozzle (10), and the surface of the vibration plate (104) is coated with a composite crystal film.

7. The converting furnace system according to claim 1, characterized in that: The vertical lengths of the multiple groups of heat exchange tubes (81) of the water-cooled hanging screen (8) gradually decrease along the flue gas flow direction.

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