Regenerative burner with gravity dust removal

Abstract

The utility model discloses a kind of heat accumulating burner with gravity dedusting, belong to industrial heating furnace technical field.Series connection is arranged between burner and heat accumulating box gravity deduster, and dust outlet of gravity deduster is connected with dust collection system.Burner alternately works in exhaust smoke heat accumulating state and air supply combustion state, airflow path reverses.In exhaust smoke heat accumulating state, high-temperature dust-containing flue gas enters gravity deduster through burner, and flow cross section expands to make airflow decelerate and change direction, utilize the synergistic effect of dust self-gravity and airflow state change, make ≥20 μm iron oxide scale and dust separate and settle to dust collection system, separation efficiency is >85%.After clean flue gas enters heat accumulating box and exchanges heat, it is emptied out.The utility model effectively solves the problem of heat accumulating body blockage, significantly prolongs heat accumulating body service life (to 24 months or more), system comprehensive energy efficiency is improved by 12%, and compact structure, easy to integrated reconstruction.

Description

Technical Field

[0001] This utility model relates to the field of industrial heating furnace technology, specifically a regenerative burner that effectively solves the problem of heat storage blockage by gravity dust removal. Background Technology

[0002] Blast furnace gas is a byproduct of ironmaking in steel plants. It contains only about 30% combustible components and has a low calorific value. Direct combustion of blast furnace gas cannot meet the heating temperature requirements of steel billets. Traditional solutions require mixing with high-calorific-value gas (such as coke oven gas), resulting in low utilization and a large amount of surplus gas being directly emitted, causing energy waste and environmental pollution.

[0003] Regenerative combustion technology preheats blast furnace gas to above 1100℃ using ceramic regenerators, achieving efficient utilization. The regenerative burner is the most critical piece of equipment in a regenerative heater, a highly efficient combustion device whose working principle is based on the recovery and reuse of heat energy. The system includes at least two burners, two accumulators, a heat recovery system, and corresponding control devices. During operation, one burner is responsible for combustion, while the other is in exhaust mode, storing the heat from the exhaust gas in the accumulator. When the heat in the accumulator reaches a certain level, the reversing valve in the system activates, switching the functions of the two burners. The burner that was originally burning becomes the exhaust burner, while the burner that was originally exhausting begins to burn. This process is continuously repeated, achieving effective recovery and utilization of heat energy.

[0004] In terms of the materials used in the regenerator, the main types are ceramic balls and ceramic honeycomb structures, with ceramic honeycomb regenerator burners being the mainstream. The micropores in ceramic honeycomb regenerators have small diameters, making them easily clogged by impurities such as iron oxide scale (10-200μm particle size) and dust in the flue gas. Dust blockage accounts for 68% of regenerator burner malfunctions and furnace shutdowns. Blockage leads to:

[0005] 1. When the blockage rate is greater than 30%, the smoke exhaust resistance increases by more than 150%, causing the gas supply / smoke exhaust function to fail.

[0006] 2. Uneven heating of the ceramic heat storage body, with local temperature differences exceeding 250℃, can cause cracks and damage.

[0007] 3. Monthly shutdowns are required for clearing blockages, and frequent shutdowns for cleaning increase maintenance costs.

[0008] Existing technologies mostly employ filters or increase the pore size of the heat storage medium, but existing anti-clogging solutions have the following shortcomings:

[0009] Filter screen solution: Initial pressure loss increases by 120-150Pa, pores enlarge after high-temperature ablation, filter screen fails, separation efficiency decreases to 60% within 3 months.

[0010] Increasing the pore size of the heat storage medium: For every 0.5 mm increase in pore size, the heat recovery efficiency decreases by 7-9%, resulting in a 15% increase in gas consumption.

[0011] Therefore, there is an urgent need to develop a regenerative burner that is resistant to clogging and does not lose thermal efficiency. Utility Model Content

[0012] To address the aforementioned problems, this invention provides a regenerative burner with gravity dust removal. By expanding the flow cross-section and reducing the airflow velocity, the dust is separated by its own gravity and inertia, effectively removing iron oxide scale and dust particles from the flue gas, effectively solving the problem of heat storage blockage, while maintaining heat recovery efficiency.

[0013] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0014] A regenerative burner with gravity dust removal includes a burner, a gravity dust collector, a heat storage box, and an ash collection system. The gravity dust collector is connected in series between the burner and the heat storage box. The dust outlet of the gravity dust collector is connected to the ash collection system, forming an integrated process of "combustion-separation-heat storage-ash removal".

[0015] The gravity dust collector includes four gas inlets, a gas outlet, a cylindrical section, a guide cone, a central pipe, a conical section, and one gas inlet. A guide cone is provided on the inner side of the top of the cylindrical section, with the cone surface at an angle of 30°-60° to the horizontal plane (to guide the airflow and improve separation efficiency).

[0016] The ratio of the diameter d of the central exhaust pipe to the diameter D of the cylinder section is 0.35-0.45 (preferably 0.4).

[0017] The ash collection system includes valves, ash hoppers, airlock valves, and nitrogen inlets; the nitrogen inlets for backflushing are located on the side wall of the ash hoppers.

[0018] The bottom of the ash collection system is equipped with an ash discharge port with an airlock valve (for periodic ash discharge to prevent secondary dust generation).

[0019] The burner operates alternately in flue gas heat storage state and air supply combustion state, and the airflow path is reversed in the two states through structural design.

[0020] Preferred solution:

[0021] The cone angle of the conical section is 28°-42° (32° is optimal for dust discharge).

[0022] The angle between the nitrogen inlet axis and the tangential angle of the ash tank wall is 30°±5° (to form a swirling backflushing flow and avoid ash accumulation and blockage).

[0023] The inner walls of the gravity dust collector and heat storage tank are coated with high-temperature resistant and wear-resistant paint to reduce wall temperature and extend equipment life.

[0024] All interfaces are connected using high-temperature flanges, with graphite sealing rings sandwiched between the flanges (to ensure high-temperature sealing).

[0025] The beneficial effects of this utility model are as follows:

[0026] Highly efficient anti-clogging: The gravity dust collector separates impurities such as iron oxide scale and dust with a diameter of ≥20μm from the flue gas, with a particle separation efficiency of >85%, which significantly reduces the clogging rate of the heat storage body and solves the problem of airflow interruption caused by clogging.

[0027] Extended service life: Reduced internal temperature difference of the heat storage body, elimination of thermal stress cracks, crack incidence rate reduced by 80%, and service life of the heat storage body extended from 7 months to more than 24 months;

[0028] Energy efficiency improvement: Compared with traditional filtration solutions, which increase pressure loss by 2%, the system energy efficiency is improved by 12%;

[0029] Structural compatibility: It can be directly integrated into existing burner systems with low modification costs. Attached Figure Description

[0030] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0031] Figure 1 This is a schematic diagram of the elevation structure of Embodiment 1 of this utility model;

[0032] Figure 2 This is a top view of Embodiment 1 of the present invention.

[0033] Figure 3 This is a schematic diagram of the airflow direction in the flue gas heat storage state of Embodiment 1 of this utility model;

[0034] Figure 4 This is a schematic diagram of the airflow direction during the combustion state of Embodiment 1 of this utility model;

[0035] Figure 5 This is a schematic diagram of the elevation structure of Embodiment 2 of this utility model;

[0036] Figure 6 This is a schematic diagram of the airflow direction in the flue gas heat storage state of Embodiment 2 of this utility model;

[0037] Figure 7 This is a schematic diagram of the airflow direction during the combustion state of the air supply in Embodiment 2 of this utility model.

[0038] In the diagram: To clearly show the location of each part, the spacing or dimensions may be exaggerated. The diagram is for illustrative purposes only.

[0039] Among them: 1. Burner;

[0040] 2. Gravity dust collector; 21. Gas interface four; 22. Gas inlet; 23. Cylindrical section; 24. Guide cone; 25. Central pipe; 26. Conical section; 27. Gas interface one;

[0041] 3. Heat storage box; 31. Heat storage body; 32. Gas interface two; 33. Inspection hole; 34. Gas interface three;

[0042] 4. Ash collection system; 41. Valves; 42. Ash hopper; 43. Airlock valve; 44. Nitrogen port. Detailed Implementation

[0043] (Taking steel rolling heating furnace as an example)

[0044] Example 1:

[0045] like Figure 1 , Figure 2 As shown, this embodiment provides a regenerative burner with gravity dust removal.

[0046] Structural parameters:

[0047] The diameter of the cylindrical section 23 of the gravity dust collector is D = 300 mm, the cone angle of the conical section 26 is 32°, the angle between the cone surface of the guide cone 24 and the horizontal plane is 45°, the distance from the cone top to the lower port of the central tube 25 is 20 mm, the diameter of the central tube is d = 120 mm (0.4D), and the height of the gravity dust collector is H = 390 mm (1.3D).

[0048] Structural layout and installation:

[0049] The gas interface 21 of the gravity dust collector 2 is connected to the burner 1 through a flange; the gas interface 27 is connected to the gas interface 34 of the heat storage box 3 through a flange; the conical section 26 (dust outlet) is connected to the ash collection system 4 through a valve 41.

[0050] The gravity dust collector 2 and the ash collection system 4 are arranged concentrically.

[0051] The cylindrical section 23 and the conical section 26 are arranged concentrically.

[0052] The central tube 25 is located at the center of the cylindrical section 23 and is concentric.

[0053] Gas interface 4 21 is located at the top of cylinder section 23.

[0054] Gas inlet 27 is located on the upper part of the cylinder section 23 and is arranged opposite to gas inlet 21.

[0055] The guide cone 24 is located inside the upper part of the cylindrical section 23.

[0056] The cylinder section 23 is connected to the gas interface 27.

[0057] The bottom end of the central tube 25 is connected to the cylinder section 23; the top end of the central tube 25 is connected to the gas interface 21.

[0058] The valves 41, ash hopper 42, and airlock valve 43 of the ash collection system 4 are arranged vertically.

[0059] The side wall of the ash tank 42 is provided with a nitrogen port 44 for backflushing, and the angle between the port axis and the tangential direction of the ash tank wall is 30°.

[0060] The inner walls of the gravity dust collector 2 and the heat storage box 3 are coated with a composite silicon carbide wear-resistant layer.

[0061] All interfaces are connected using high-temperature flanges, with a 0.5mm graphite sealing ring sandwiched between the flanges.

[0062] The heat storage body 31 is a ceramic honeycomb structure.

[0063] Workflow:

[0064] 1. Smoke exhaust heat storage state ( Figure 3 ): 1100℃ dusty flue gas → burner 1 → gas interface 4 21 → central tube 25 → cylinder section 23 (the flow cross section is expanded, causing the airflow speed to suddenly drop from high speed to 1-2m / s, and at the same time the flow direction is changed. Dust particles with a particle size ≥20μm and high density cannot continue to move with the airflow due to inertial force and gravity, and settle into the conical section 26) → clean flue gas through gas interface 1 27 → gas interface 3 34 → heat exchange in heat storage body 31 → 130℃ flue gas is discharged through gas interface 2 32.

[0065] 2. Air supply combustion state ( Figure 4 ): Air → Gas Interface 2 32 → Heat Storage 31 Preheating → Gas Interface 3 34 → Gas Interface 1 27 → Cylinder Section 23 → Central Pipe 25 → Gas Interface 4 21 → Burner 1 Combustion (using the heat of the heat storage to improve combustion efficiency).

[0066] 3. Dust removal operation:

[0067] Nitrogen backflushing: pulse backflushing (0.6MPa, 0.2s / time) every shift to prevent ash accumulation and caking.

[0068] Ash discharge: When the ash hopper 42 is full, the airlock valve 43 opens to prevent secondary dust generation.

[0069] Example 2:

[0070] like Figure 5 , Figure 6 , Figure 7 As shown, this embodiment provides another regenerative burner structure with gravity dust removal.

[0071] The main difference from Embodiment 1 is that, to simplify the equipment structure, the gravity dust collector 2 in this embodiment consists of gas interface 21, gas inlet 22, cylindrical section 23, conical section 26, and gas interface 27, omitting the guide cone 24 and central pipe 25. The airflow channel is straight-through, utilizing the cylindrical structure to reduce flow velocity and change flow direction. Other structural features (such as series connection, dust collection system, interface connection method, working state switching, dust removal operation, etc.) and preferred parameters (such as conical section cone angle 32°, nitrogen interface angle 30°, wear-resistant coating, flange seal, etc.) are the same as in Embodiment 1.

[0072] In the state of flue gas heat storage ( Figure 6 ) and air supply combustion state ( Figure 7 In the following case, the airflow path is similar to that in Example 1, but the specific structure inside the gravity dust collector 2 is different. Similarly, the speed reduction and gravity dust removal are achieved by changing the flow cross section.

Claims

1. A regenerative burner with gravity dust collection, comprising a burner (1), a gravity dust collector (2), a heat storage box (3), and an ash collection system (4), characterized in that: A gravity dust collector (2) is connected in series between the burner (1) and the heat storage box (3); the dust outlet of the gravity dust collector (2) is connected to the ash collection system (4).

2. A regenerative burner with gravity dust removal according to claim 1, characterized in that: The gravity dust collector (2) includes a gas interface four (21), a gas inlet (22), a cylindrical section (23), a guide cone (24), a central tube (25), a conical section (26), and a gas interface one (27); the guide cone (24) is fixed to the inner side of the top of the cylindrical section (23), and the angle between its conical surface and the horizontal plane is 30°-60°.

3. A regenerative burner with gravity dust removal according to claim 2, characterized in that: The ratio of the diameter d of the central tube (25) to the diameter D of the cylindrical section (23) is 0.35-0.

45.

4. A regenerative burner with gravity dust removal according to claim 1, characterized in that: The ash collection system (4) includes a valve (41), an ash tank (42), an airlock valve (43), and a nitrogen port (44); the nitrogen port (44) for backflushing is located on the side wall of the ash tank (42), and the angle between the port axis and the tangential angle of the ash tank wall is 30°±5°.

5. A regenerative burner with gravity dust removal according to claim 4, characterized in that: The bottom of the ash collection system (4) is provided with an ash discharge port equipped with an airlock valve (43).

6. A regenerative burner with gravity dust removal according to any one of claims 1-5, characterized in that: The burner operates alternately in flue gas heat storage state and air supply combustion state, and the airflow path is reversed in the two states through structural design.

Images