Cooling and sealing device for outlet flue of melting furnace

Abstract

The utility model discloses a cooling and sealing device for an outlet flue of a melting furnace, which comprises a cylindrical flue wall, one end of the flue wall is communicated with the outlet flue of the melting furnace, the other end of the flue wall is communicated with an inlet flue of a waste heat boiler after reducing, and a cylindrical smoke blocking wall is coaxially arranged in the non-reducing end of the flue wall. The end, close to the smelting furnace, of the smoke barrier extends outwards in the radial direction to be connected to the inner wall of the flue wall, the outer wall, corresponding to the side wall of the smoke barrier, of the flue wall is communicated with an annular cooling air unit, and a double-wave metal compensator is arranged at the position, between the reducing end of the outer wall of the flue wall and the annular cooling air unit, of the outer wall of the flue wall. According to the utility model, the smoke barrier is arranged in the flue wall, so that most hazardous wastes are melted and vitrified in the hearth; cold air is introduced into the high-temperature flue gas through the annular cooling air unit for cooling, and therefore the requirement for waste heat recovery of the waste heat boiler is met. The high-temperature flue gas can stably and safely pass through the double-wave metal compensator; after the flue wall is reduced, the heat exchange efficiency of the water cooling wall can be improved, and waste heat is recycled.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste treatment engineering equipment, and in particular relates to a cooling and sealing device for a flue at an outlet of a melting furnace. Background Art

[0002] With the development of urbanization and industrialization, urban domestic waste has increased rapidly, and the types and accumulation of industrial waste have increased. In view of the treatment of fly ash and bottom slag from the incineration of urban waste, sludge, salt slag and other hazardous wastes with high heavy metal content associated with the energy and chemical industry, the national standard "Technical Requirements for Products of Solid Waste Vitrification Treatment" (GB / T41015) recommends vitrification treatment technology. Vitrification treatment of solid hazardous waste is a zero-pollution disposal technology for hazardous waste. Under high temperature conditions, the calorific value of hazardous waste is fully utilized to incinerate, gasify or pyrolyze organic matter, and inorganic matter forms a uniform molten state under the action of certain fluxes and additives, and then cools to form a glassy substance with an amorphous structure. The products of vitrification treatment can be used as substitutes for building materials.

[0003] Regardless of the type of furnace used for vitrification, the furnace temperature must reach more than 1500℃ to achieve melting. In order to achieve energy saving and consumption reduction and reduce processing costs, recycling the waste heat of the melting furnace flue gas is a feasible measure. However, the functions, operating parameters and furnace structures of the melting furnace and the waste heat boiler are different. The design requirements for the flue between the melting furnace and the waste heat boiler are relatively high, and conventional flues cannot meet the technical requirements; first, the high-temperature flue gas needs to be cooled, and then sufficient high-temperature strength is required to withstand its own load and the effect of thermal stress without losing structural strength, deformation, and fracture; wear and corrosion resistance and good sealing performance are also required. Utility Model Content

[0004] The utility model aims to provide a cooling and sealing device for a flue at an outlet of a melting furnace, which solves the problem that the high-temperature flue gas of the existing melting furnace cannot be used for waste heat recovery in a waste heat boiler.

[0005] The technical solution adopted by the utility model is: a cooling and sealing device for the flue at the outlet of the melting furnace, comprising a cylindrical flue wall, one end of the flue wall being connected to the outlet flue of the melting furnace, and the other end being connected to the inlet flue of the waste heat boiler after being reduced in diameter, a cylindrical smoke barrier wall being coaxially arranged inside the non-reduced end of the flue wall, the smoke barrier wall extending radially outwardly near one end of the melting furnace and connected to the inner wall of the flue wall, an outer wall of the flue wall corresponding to the side wall of the smoke barrier wall being connected to an annular cooling air unit, and a double-wave metal compensator being arranged on the outer wall of the flue wall between the reduced end thereof and the annular cooling air unit.

[0006] The utility model is also characterized in that:

[0007] The annular cooling air unit includes a plurality of swirl air inlets evenly spaced along the circumferential direction of the flue wall side wall. The plurality of swirl air inlets are connected to an annular bellows located on the outer wall of the flue wall. Air supply ports are provided on opposite sides of the annular bellows.

[0008] The inner diameter of the smoke barrier wall is 0.45 times the inner diameter of the non-reduced end of the flue wall, and the length of the smoke barrier wall is 0.35 to 0.40 times the inner diameter of the non-reduced end of the flue wall.

[0009] The axial angle between the swirl air inlet and the flue wall is 30°.

[0010] The radial angle between the swirl air inlet and the flue wall is 30°.

[0011] There are 8 swirl air inlets.

[0012] A pressure sensor and a temperature sensor are provided at the reduced diameter end of the flue wall.

[0013] The flue wall includes a steel outer wall layer, a refractory ceramic fiber layer, a medium-quality thermal insulation castable layer and a corundum refractory castable layer, which are connected from the outside to the inside in sequence by anchor nails made of chromium-nickel austenitic stainless steel rods. The two ends of the steel outer wall layer are welded and sealed to the melting furnace outlet flue and the waste heat boiler inlet flue respectively.

[0014] A disconnection port is provided on the steel outer wall layer at a position inside the double-wave metal compensator, and the steel outer wall layers at both ends of the disconnection port are respectively welded to both ends of the double-wave metal compensator, and a Z-shaped expansion joint penetrating the refractory ceramic fiber layer, the medium-quality thermal insulation castable layer and the corundum refractory castable layer is provided corresponding to the disconnection port in the steel outer wall layer, and the expansion joint is filled with refractory ceramic fiber material.

[0015] The smoke barrier wall adopts chromium-nickel austenitic stainless steel rod steel bar woven inner frame and corundum refractory castable outer protection.

[0016] The beneficial effects of the utility model are as follows: the cooling and sealing device of the flue at the outlet of the melting furnace of the utility model arranges a smoke barrier wall inside the flue wall to maintain the pressure of the furnace when the flue gas flows out of the furnace of the melting furnace, and captures hazardous waste fly ash to reduce the escape amount, so that most of the hazardous waste is melted and vitrified in the furnace; cold air is introduced into the high-temperature flue gas through the annular cooling air unit to cool it down, thereby meeting the requirements of the waste heat boiler for recovering waste heat; the expansion and contraction caused by the different temperature differences in the flues on both sides is absorbed by the double-wave metal compensator, ensuring the smooth and safe passage of the high-temperature flue gas; after the flue wall is reduced in diameter, it can adapt to the flexible connection of the flue interface of the waste heat boiler, and increase the flow rate of the flue gas entering the waste heat boiler, improve the heat exchange efficiency of the water-cooled wall, and recover the waste heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the connection position of the cooling and sealing device of the flue at the outlet of the melting furnace of the utility model;

[0018] Figure 2 It is a structural schematic diagram of the cooling and sealing device of the flue at the outlet of the melting furnace of the utility model;

[0019] Figure 3 yes Figure 2 The AA cross-sectional structural diagram of the cooling and sealing device of the flue at the outlet of the melting furnace of the utility model;

[0020] Figure 4 It is a partially enlarged schematic diagram of the location of the double-wave metal compensator in the cooling and sealing device of the flue at the outlet of the melting furnace of the utility model.

[0021] In the figure, 1. melting furnace, 2. flue wall, 3. waste heat boiler, 4. smoke barrier wall, 5. annular cooling air unit, 6. double-wave metal compensator, 7. pressure sensor, 8. temperature sensor;

[0022] 21. Anchor nails, 22. Steel outer wall layer, 23. Refractory ceramic fiber layer, 24. Medium quality thermal insulation castable layer, 25. Corundum refractory castable layer, 26. Disconnection port, 27. Expansion joint;

[0023] 41. Endoskeleton;

[0024] 51. Annular bellows, 52. Swirl air inlet, 53. Air supply port. DETAILED DESCRIPTION

[0025] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0026] Example 1

[0027] The utility model provides a cooling and sealing device for a flue at a melting furnace outlet, such as Figure 1 As shown, it includes a cylindrical flue wall 2, one end of which is connected to the outlet flue of the melting furnace 1. The melting furnace 1 adopts a vertical upright circular furnace, and the furnace outlet is bent to the horizontal direction; the other end of the flue wall 2 is connected to the inlet flue of the waste heat boiler 3 after the diameter is reduced. The high-temperature flue gas generated by the melting furnace 1 passes through the flue wall 2, and the flue gas temperature is reduced to below 1100°C through air cooling, and then enters the waste heat boiler 3 to recover waste heat.

[0028] like Figure 2 As shown, a cylindrical smoke barrier 4 is coaxially arranged inside the non-reduced end of the flue wall 2. The smoke barrier 4 extends radially outwards near the end of the melting furnace 1 and is connected to the inner wall of the flue wall 2. The axial cross section is L-shaped. The smoke barrier 4 uses a chrome-nickel austenitic stainless steel bar steel bar braided inner skeleton 41 and a corundum refractory castable outer protection. The smoke barrier 4 can reduce the diameter of the outlet flue of the melting furnace 1 on the one hand, and can maintain the pressure of the furnace; on the other hand, a vortex can be formed at the smoke barrier 4, so that large particles of fly ash are diverted back to the melting furnace 1, reducing the amount of fly ash escaping.

[0029] like Figure 2 and Figure 3 As shown, the outer wall of the flue wall 2 corresponds to the side wall of the smoke barrier wall 4 and is connected to an annular cooling air unit 5. The annular cooling air unit 5 includes 8 swirl air inlets 52 evenly spaced along the circumference of the flue wall side wall. The 8 swirl air inlets 52 form a rotating counter-jet. By designing the angle of the swirl air inlet 52 and the horizontal arm length of the smoke barrier wall 4, for example, the inner diameter of the smoke barrier wall 4 is preferably 0.45 times the inner diameter of the non-reduced end of the flue wall 2, the length of the smoke barrier wall 4 is 0.35-0.40 times the inner diameter of the non-reduced end of the flue wall 2, and the axial angle between the swirl air inlet 52 and the flue wall 2 is 30°. Then, the right end of the smoke barrier wall 4 just extends to the swirl air inlet 52 to form a shield, thereby reducing the impact of high-temperature flue gas on the swirl air inlet 52 and the flow direction of the cooling air jet. Disturbance; the radial angle between the swirl air inlet 52 and the flue wall 2 is 30°, so the cooling air forms a swirl in the jet process, and the imaginary tangent circle of the swirl is exactly the same as the size of the flue in the smoke barrier wall 4. The confluence section of the cooling air and the high-temperature flue gas at the outlet of the smoke barrier wall 4 is located in the mixed cooling air chamber space behind the smoke barrier wall 4. This design enables the cooling air to be better mixed with the high-temperature flue gas for cooling, thereby realizing the cooling function, reducing the high-temperature flue gas from 1500°C to below 1100°C, ensuring that the conventional waste heat boiler 3 can be used to meet the waste heat recovery requirements and reduce the cost of the waste heat boiler equipment; in addition, the external cooling air wraps the high-temperature flue gas for swirl heat exchange, which can also reduce the scouring and erosion of the inner wall of the flue wall 2 by the fly ash of the high-temperature flue gas, and reduce the wear of the flue wall 2 by the fly ash. After the high-temperature flue passes through the mixed cooling air chamber, the diameter of the interface with the waste heat boiler 3 is reduced along the cooling wind jet angle. The reduction angle is consistent with the jet angle, so that the cooling wind jet is disturbed internally during the mixing process with the high-temperature flue gas, but cannot diffuse externally, and the effect is better; at the same time, the reduction helps to reduce the caliber of the interface of the waste heat boiler 3, making the design of the flue interface of the waste heat boiler 3 more flexible and safe. The furnaces of the front and rear melting furnaces 1 and the furnaces of the waste heat boiler 3 are both large spaces. The design of the high-temperature reduced flue can form a Venturi effect at the entrance of the waste heat boiler 3, so that the flow rate of the flue gas after cooling and mixing is increased, and the flue gas mixed flow is more smoothly into the waste heat boiler 3 to recover waste heat. The eight swirl air inlets 52 are connected to the annular wind box 51 located on the outer wall of the flue wall 2. The opposite sides of the annular wind box 51 are provided with air supply ports 53, which can make the air volume and air pressure in the annular wind box 51 uniform, thereby ensuring the uniformity of the flow field parameters of the eight swirl air inlets 52.

[0030] like Figure 2 and Figure 4As shown, the outer wall of the flue wall 2 is provided with a double-wave metal compensator 6 between its reduced diameter end and the annular cooling air unit 5. The flue wall 2 includes a steel outer wall layer 22, a refractory ceramic fiber layer 23, a medium-quality thermal insulation castable layer 24 and a corundum refractory castable layer 25, which are connected from the outside to the inside in sequence by anchor nails 21 made of chromium-nickel austenitic stainless steel rods, to ensure that the high-temperature flue wall 2 has sufficient strength to resist high-temperature residual stress, wear, corrosion damage, etc. caused by high-temperature flue gas on the flue. The two ends of the steel outer wall layer 22 are welded and sealed with the outlet flue of the melting furnace 1 and the inlet flue of the waste heat boiler 3 respectively. A disconnection port 26 is provided on the steel outer wall layer 22 at a position inside the double-wave metal compensator 6. The steel outer wall layer 22 at both ends of the disconnection port 26 is welded to the two ends of the double-wave metal compensator 6 respectively. A Z-shaped expansion joint 27 penetrating the refractory ceramic fiber layer 23, the medium-quality thermal insulation castable layer 24 and the corundum refractory castable layer 25 is provided corresponding to the disconnection port 26 in the steel outer wall layer 22. The expansion joint 27 is filled with refractory ceramic fiber material, and its good flexibility can absorb the expansion and contraction caused by the temperature difference of the flues on both sides. At the same time, the section is located at the end of the inner annular cooling air chamber. The low-temperature cooling wind protects the refractory ceramic fiber from being eroded by high-temperature flue gas, thereby increasing its service life, thereby ensuring the good flexibility and sealing of the flue wall 2.

[0031] Example 2

[0032] The utility model provides a cooling and sealing device for a flue at a melting furnace outlet, such as Figure 1 and Figure 2 As shown, a pressure sensor 7 and a temperature sensor 8 are provided at the reduced diameter end of the flue wall 2. During operation, the high-temperature flue mixing air chamber is monitored by the pressure sensor 7 and the temperature sensor 8, and the air volume and air pressure parameters of the annular cooling air unit 5 are adjusted through feedback control to achieve the purpose of safe operation.

[0033] Example 3

[0034] The utility model provides a cooling sealing device for the flue at the outlet of the melting furnace. The cooling air to the air outlet 53 adopts the low-temperature dry flue gas after the system downstream flue gas purification, and gradually reduces the content of O2 and N2 entering the waste heat boiler 3. Reducing the amount of N2 can reduce the high-temperature NO x The production of O2 can reduce the pressure of the subsequent flue gas purification section; reducing the amount of O2 can reduce the corrosion of the subsequent sections such as the waste heat boiler and the tail flue. The cooling wind does not directly use air, which can avoid the impact of cold wind on the structural stress of the flue wall 2 in extreme winter weather and increase safety in use.

Claims

1. A cooling and sealing device for the flue at the outlet of a melting furnace, characterized in that: The invention comprises a cylindrical flue wall (2), one end of the flue wall (2) is connected to the outlet flue of a melting furnace (1), and the other end is connected to the inlet flue of a waste heat boiler (3) after being reduced in diameter; a cylindrical smoke barrier wall (4) is coaxially arranged inside the non-reduced end of the flue wall (2); the smoke barrier wall (4) is radially extended outwardly at one end close to the melting furnace (1) and connected to the inner wall of the flue wall (2); an annular cooling air unit (5) is connected to the outer wall of the flue wall (2) corresponding to the side wall of the smoke barrier wall (4); and a double-wave metal compensator (6) is arranged on the outer wall of the flue wall (2) between the reduced end thereof and the annular cooling air unit (5).

2. The cooling and sealing device for the flue at the outlet of the melting furnace according to claim 1, characterized in that: The annular cooling air unit (5) comprises a plurality of swirl air inlets (52) uniformly spaced along the circumference of the flue wall side wall, the plurality of swirl air inlets (52) being commonly connected to an annular wind box (51) located on the outer wall of the flue wall (2), and air supply ports (53) are provided on opposite sides of the annular wind box (51).

3. The cooling and sealing device for the flue at the outlet of the melting furnace according to claim 2, characterized in that: The inner diameter of the smoke barrier wall (4) is 0.45 times the inner diameter of the non-reduced end of the flue wall (2), and the length of the smoke barrier wall (4) is 0.35 to 0.40 times the inner diameter of the non-reduced end of the flue wall (2).

4. The cooling and sealing device for the flue gas outlet of a melting furnace according to claim 3, characterized in that: The axial angle between the swirl air inlet (52) and the flue wall (2) is 30°.

5. The cooling and sealing device for the flue at the outlet of the melting furnace according to claim 3, characterized in that: The radial angles between the swirl air inlet (52) and the flue wall (2) are both 30°.

6. The cooling and sealing device for the flue at the outlet of the melting furnace according to claim 5, characterized in that: The swirl air inlets (52) are provided in eight numbers.

7. The cooling and sealing device for the flue at the outlet of a melting furnace according to claim 1, characterized in that: A pressure sensor (7) and a temperature sensor (8) are provided at the reduced diameter end of the flue wall (2).

8. The cooling and sealing device for the flue at the outlet of a melting furnace according to claim 1, characterized in that: The flue wall (2) comprises a steel outer wall layer (22), a refractory ceramic fiber layer (23), a medium-quality thermal insulation castable layer (24) and a corundum refractory castable layer (25) which are connected in sequence from the outside to the inside by anchoring nails (21) made of chromium-nickel austenitic stainless steel rods, and the two ends of the steel outer wall layer (22) are welded and sealed to the outlet flue of the melting furnace (1) and the inlet flue of the waste heat boiler (3) respectively.

9. The cooling and sealing device for the flue at the outlet of a melting furnace according to claim 8, characterized in that: A disconnection opening (26) is provided on the steel outer wall layer (22) at a position located inside the double-wave metal compensator (6); the steel outer wall layer (22) at both ends of the disconnection opening (26) is respectively welded to both ends of the double-wave metal compensator (6); a Z-shaped expansion joint (27) penetrating the refractory ceramic fiber layer (23), the medium-quality thermal insulation castable layer (24) and the corundum refractory castable layer (25) is provided in the steel outer wall layer (22) corresponding to the disconnection opening (26); and the expansion joint (27) is filled with refractory ceramic fiber material.

10. The cooling and sealing device for the flue at the outlet of a melting furnace according to claim 1, characterized in that: The smoke barrier wall (4) is made of a chrome-nickel austenitic stainless steel bar braided inner skeleton (41) and a corundum refractory castable outer protection.

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