Horizontal welded finned tube type electric furnace waste heat boiler
By welding fins on the heat exchange pipe of the electric furnace waste heat boiler to form an elliptical flow field, the problem of poor dust cleaning effect caused by high viscosity of flue gas dust is solved, and efficient dust settlement and heat transfer efficiency are achieved, which is highly economical.
Patent Information
- Application Number
- CN202421313265.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-11
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-11
AI Technical Summary
The dust in the flue gas in the waste heat boiler of the electric furnace is more sticky, resulting in poor ash cleaning effect, reducing the heat transfer efficiency of the boiler, and possibly causing downtime.
The horizontal welded fin tube structure is adopted. By welding an elongated fin on the windward and leeward surfaces of the heat exchange tube, an elliptical flow field is formed, which reduces the probability of the pipe wall being ash, and allows more dust to settle to the ash bucket and is discharged.
It effectively reduces the risk of ash blockage, improves the heat transfer efficiency of the boiler, and saves pipe materials compared with light pipes and spiral fin tube structures, and has higher economicality.
Smart Images
Figure CN222669967U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a horizontal welded fin tube type electric furnace waste heat boiler. Background Art
[0002] Electric furnaces play an important role in the short-process steelmaking process of steel mills, and their energy consumption is also very alarming, so it is extremely necessary to recover the waste heat from the exhaust gas produced by steelmaking.
[0003] An important difficulty in recovering waste heat from electric furnaces is that there is a lot of dust in the flue gas. The grease contained in scrap steel and the oil-containing burners used in steelmaking make the dust produced by steelmaking sticky and difficult to remove. If the cleaning effect is not good, the heat transfer efficiency of the boiler will be reduced, and even dust bridging inside the boiler will cause shutdown accidents.
[0004] The boiler heat exchange surface is composed of a curved water-cooled flue, an evaporator, and an economizer, and an ash hopper is provided under the entire flue gas flow channel. At present, domestic electric furnace waste heat boilers are still mainly vertical structures, because vertical boilers occupy a small area, and because the flue gas is perpendicular to the heating surface tube bundle, the flue gas flushes the tube bundle evenly, and the heat exchange effect is good. However, because the vertical boiler finally falls ash at the boiler outlet, all the dust in the flue gas is flushed with all the tube bundles, and the dust is not effectively settled and removed when the flue gas passes through the boiler channel. Especially for the structure where the flue gas enters from the bottom and exits from the top, it is inevitable that the ash will be blocked by bridging. Although the horizontal boiler occupies a larger area, the dust continues to fall into the lower ash hopper when the flue gas passes through the boiler channel, so the probability of ash blockage is much smaller than that of the vertical structure.
[0005] Boiler heating surface form: In the early days, electric furnace waste heat boilers used heat pipes, but due to problems such as heat pipe failure and exhaust gas temperature not meeting requirements, heat pipe electric furnace waste heat boilers were eliminated from the market. After the water pipe solution was introduced to the market, some manufacturers believed that the ash content was not high, so they chose spiral finned tubes for the heating surface. They ignored the large amount of oil and fat in the flue gas dust, which easily adhered to the tube wall. Therefore, electric furnace waste heat boilers with spiral finned tube structures were prone to blockage and bridging, and gradually withdrew from the market. Now the main market push is the light tube form, which does greatly reduce the probability of ash blockage and bridging. However, because electric furnace waste heat boilers generally have a large heating area, the boiler volume will be relatively large without an expanded heating surface, and the economy is poor. Utility Model Content
[0006] The purpose of the utility model is to provide a horizontal welded fin tube electric furnace waste heat boiler, which is welded with long flat steel in the length direction of the tube bundle along the flue gas flow direction to expand the heating surface. Compared with the bare tube structure, a large amount of pipe material is saved, and compared with the spiral fin tube form, it is not easy to get dusty.
[0007] The technical solution adopted by the utility model is:
[0008] A horizontal welded finned tube electric furnace waste heat boiler comprises a flue gas inlet, a settling chamber, a turning channel, a plurality of evaporators, a plurality of economizers and a flue gas outlet which are connected in sequence, and heat exchange tubes are arranged at least in the plurality of evaporators and the plurality of economizers; characterized in that:
[0009] A fin is welded on the windward side and the leeward side of the heat exchange tube respectively. The fin is in a long strip shape and is arranged along the length direction of the heat exchange tube.
[0010] The horizontal welded fin tube electric furnace waste heat boiler, wherein: the heat exchange tube is connected to a steam drum.
[0011] The horizontal welded fin tube electric furnace waste heat boiler, wherein: an ash hopper is arranged below each evaporator and each economizer.
[0012] The horizontal welded fin tube electric furnace waste heat boiler, wherein: the bottom side of the turning channel is connected to the upper part of the settling chamber, and one side of the turning channel is connected to the horizontally arranged dry evaporators and several economizers.
[0013] The horizontal welded fin tube type electric furnace waste heat boiler, wherein: the cross section of the fin is rectangular, and the short side of the rectangle faces the windward side or the leeward side of the heat exchange tube.
[0014] The horizontal welded fin tube electric furnace waste heat boiler, wherein: the ratio of the length of the short side of the rectangle to the radius of the heat exchange tube is 1:5 to 1:10.
[0015] The horizontal welded fin tube electric furnace waste heat boiler, wherein: the ratio of the length of the long side of the rectangle to the radius of the heat exchange tube is 5:3 to 2:3.
[0016] When the flue gas flows through the heat exchange tube, the flue gas does not completely wrap the heat exchange tube, but forms an elliptical flow field, thereby reducing the probability of dust on the tube wall of the heat exchange tube. The dust is not easily adsorbed on the tube wall and settles more in the ash hopper and is discharged. Therefore, from the perspective of flue gas flow field and economic efficiency, the utility model is superior to the electric furnace waste heat boiler with a bare tube structure and the electric furnace waste heat boiler with a spiral fin tube structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the overall structure of a horizontal welded fin tube electric furnace waste heat boiler.
[0018] Figure 2 It is a schematic diagram of the planar structure of the heat exchange tube and its fins.
[0019] Figure 3 It is a schematic diagram of the longitudinal cross-section structure of the heat exchange tube and its fins.
[0020] Explanation of reference numerals: flue gas inlet 1; settling chamber 2; turning channel 3; evaporator 4; economizer 5; flue gas outlet 6; heat exchange tube 7; fin 71; steam drum 8; ash hopper 9. DETAILED DESCRIPTION
[0021] like Figure 1 As shown, the utility model provides a horizontal welded fin tube electric furnace waste heat boiler, comprising a flue gas inlet 1, a settling chamber 2, a turning channel 3, a plurality of evaporators 4, a plurality of economizers 5 and a flue gas outlet 6 which are connected in sequence, a heat exchange tube 7 is arranged in the turning channel 3, the plurality of evaporators 4 and the plurality of economizers 5, the heat exchange tube 7 is connected to a steam drum 8, and an ash hopper 9 is arranged below each evaporator 4 and each economizer 5;
[0022] When in use, the high-temperature flue gas enters the settling chamber 2, clears some dust impurities, enters the turning channel 3 upward, turns horizontally and is transported to several evaporators 4 and several economizers 5, transfers heat to the heat exchange tube 7, leaves dust impurities in the ash hopper 9, and is finally discharged from the flue gas outlet 6; the water in the heat exchange tube 7 absorbs the heat of the high-temperature flue gas and stores the heat in the steam drum 8;
[0023] In order to improve the heat transfer efficiency and reduce dust, Figure 2 , Figure 3 As shown, in the present invention, a fin 71 is welded on the windward side and the leeward side of the heat exchange tube 7 , respectively. The fin 71 is in a long strip shape and is arranged along the length direction of the heat exchange tube 7 .
[0024] The cross section of the fin is rectangular, and the short side of the rectangle faces the windward side or the leeward side of the heat exchange tube. The ratio of the length of the short side of the rectangle to the radius of the heat exchange tube is 1:5 to 1:10. The ratio of the length of the long side of the rectangle to the radius of the heat exchange tube is 5:3 to 2:3.
[0025] When the flue gas flows through the heat exchange tube 7, the flue gas does not completely wrap the heat exchange tube 7, but forms an elliptical flow field, thereby reducing the probability of dust sticking to the tube wall of the heat exchange tube 7. The dust is not easily adsorbed on the tube wall and settles more to the ash hopper 9 and is discharged.
[0026] Therefore, from the perspective of flue gas flow field and economy, the utility model is superior to the electric furnace waste heat boiler with a bare tube structure and the electric furnace waste heat boiler with a spiral fin tube structure.
[0027] In summary, the horizontal welded fin 71 tube electric furnace waste heat boiler provided by the utility model has high economy and greatly reduces the risk of ash blockage.
Claims
1. A horizontal welded finned tube electric furnace waste heat boiler, comprising a flue gas inlet, a settling chamber, a turning channel, a plurality of evaporators, a plurality of economizers and a flue gas outlet which are connected in sequence, wherein heat exchange tubes are arranged in at least the plurality of evaporators and the plurality of economizers; characterized in that: A fin is welded on the windward side and the leeward side of the heat exchange tube respectively. The fin is in a long strip shape and is arranged along the length direction of the heat exchange tube.
2. The horizontal welded fin tube electric furnace waste heat boiler according to claim 1, characterized in that: The heat exchange tube is connected with the steam drum.
3. The horizontal welded fin tube electric furnace waste heat boiler according to claim 1, characterized in that: An ash hopper is arranged below each evaporator and each economizer.
4. The horizontal welded fin tube electric furnace waste heat boiler according to claim 1, characterized in that: The bottom side of the turning channel is connected to the upper part of the settling chamber, and one side of the turning channel is connected to the horizontally arranged dry evaporators and a plurality of economizers.
5. The horizontal welded fin tube electric furnace waste heat boiler according to claim 1, characterized in that: The cross section of the fin is rectangular, and the short side of the rectangle faces the windward side or the leeward side of the heat exchange tube.
6. The horizontal welded fin tube electric furnace waste heat boiler according to claim 5, characterized in that: The ratio of the length of the short side of the rectangle to the radius of the heat exchange tube is 1:5 to 1:
10.
7. The horizontal welded fin tube electric furnace waste heat boiler according to claim 5 or 6, characterized in that: The ratio of the length of the long side of the rectangle to the radius of the heat exchange tube is 5:3 to 2:3.