Natural gas melting furnace for melting aluminum ingots

Abstract

The utility model discloses a natural gas melting furnace for melting aluminum ingots, and belongs to the technical field of metal melting equipment. The melting furnace comprises a box body and a furnace body, a liquid oxygen storage tank, a VPSA oxygen generator and a waste gas treatment box are integrated in the box body, and the liquid oxygen storage tank is connected with an oxygen supply pipeline through a vaporizer; the furnace body shell adopts a gradient refractory layer structure; the oxygen supply pipeline is of a Y-shaped parallel structure, a flame arrester and a dynamic pressure balance valve are arranged in the oxygen supply pipeline, and the oxygen flow is adjusted through linkage of a pressure sensor and a controller. A water-cooling observation window is arranged on the inner wall of the furnace body, and a thermal infrared imager is installed on the outer side to monitor the temperature of a molten pool and feed back and control combustion power. According to the utility model, efficient melting, safe oxygen supply and accurate temperature control are realized through structure optimization, and the device is suitable for continuous melting scenes of aluminum ingots.

Description

Technical Field

[0001] This utility model relates to the field of aluminum processing, and in particular to a natural gas melting furnace for melting aluminum ingots. Background Technology

[0002] Natural gas melting furnaces used for melting aluminum ingots are a common type of aluminum melting equipment in industry, characterized by high efficiency, energy saving, and environmental friendliness.

[0003] Traditional natural gas melting furnaces generally use air-assisted combustion, where nitrogen in the air (accounting for 78%) dilutes the combustion reaction, limiting the flame temperature (≤1800°C) and resulting in a thermal efficiency of only 35% to 45%. This leads to excessive natural gas consumption per ton of aluminum, and at the same time, nitrogen generates a large amount of NOx (>150mg / m³) at high temperatures, with an aluminum molten metal oxidation loss rate of 3% to 5%, resulting in serious pollution. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a natural gas melting furnace for melting aluminum ingots.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] This utility model discloses a natural gas melting furnace for melting aluminum ingots, comprising a furnace body and a controller. The furnace body includes:

[0007] The enclosure contains an exhaust gas treatment box, a liquid oxygen storage tank, and a VPSA oxygen generator. A vaporizer is installed at the bottom of the liquid oxygen storage tank, and a handle and a refill port are installed at the top of the liquid oxygen storage tank.

[0008] The furnace body is installed on one side of the box. The outer shell of the furnace body is made of a gradient refractory layer. The bottom of the furnace body is equipped with a burner assembly. The burner assembly is a diffusion-type multi-stage burner assembly. The nozzle of the burner assembly is made of water-cooled high-temperature resistant alloy, and its flame pattern is adjustable.

[0009] As a preferred embodiment of this utility model, both the liquid oxygen storage tank and the VPSA oxygen generator are connected to and installed with oxygen supply pipelines. The oxygen supply pipelines are Y-shaped, and a pipeline pressure sensor is installed inside the oxygen supply pipelines.

[0010] As a preferred technical solution of this utility model, a flame arrester and a dynamic pressure balancing valve are installed in the oxygen supply pipeline (305), and the opening degree of the dynamic pressure balancing valve is controlled by the pipeline pressure sensor and the controller in real time.

[0011] As a preferred technical solution of this utility model, the inner wall of the furnace is provided with a water-cooled observation window, and an infrared thermal imager is installed on the outside of the water-cooled observation window to monitor the surface temperature distribution of the molten pool. The infrared thermal imager is connected to the controller signal to dynamically adjust the burner power.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] This utility model is a natural gas melting furnace for aluminum ingot melting. Through the synergistic design of all-oxygen combustion technology and gradient refractory layer, it significantly improves the melting efficiency of aluminum ingots, while reducing natural gas consumption per ton of aluminum by more than 30% and reducing nitrogen oxide emissions, meeting stringent environmental protection standards. It integrates a dynamic pressure balancing valve and an infrared thermal imager intelligent feedback system to achieve uniform temperature distribution in the molten pool and stable oxygen supply. Combined with a composite refractory layer and modular structure, it extends the equipment's lifespan and has the advantages of high efficiency, low carbon emissions, safety, and intelligence, making it suitable for green manufacturing of high-end aluminum materials. Attached Figure Description

[0014] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a partial structural cross-sectional view of the present invention;

[0017] In the diagram: 1. Melting furnace body; 2. Furnace body; 3. Box; 301. Waste gas treatment box; 302. Liquid oxygen storage tank; 303. VPSA oxygen generator; 304. Vaporizer; 305. Oxygen supply pipeline; 306. Pipeline pressure sensor; 4. Burner assembly. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] In the attached diagram, all identical reference numerals refer to the same components.

[0020] like Figure 1-2As shown, this utility model provides a natural gas melting furnace for melting aluminum ingots. The main body 1 of the melting furnace includes a casing 3 and a furnace body 2. The casing 3 integrates a waste gas treatment box 301, a liquid oxygen storage tank 302, and a VPSA oxygen generator 303. The waste gas treatment box 301 has a built-in cyclone dust collector and activated carbon adsorption layer for treating combustion waste gas. The liquid oxygen storage tank 302 has a capacity of 5 cubic meters, and a vaporizer 304 is installed at its bottom to convert liquid oxygen into gaseous oxygen. A replenishment port and an explosion-proof handle are provided at the top for easy liquid oxygen replenishment and equipment maintenance. The VPSA oxygen generator 303 has an oxygen production capacity of 500 cubic meters per hour and an oxygen purity of 93%.

[0021] Furthermore, furnace body 2 is installed on one side of box body 3, and its outer shell adopts a gradient refractory layer structure, consisting of a composite material working layer, a mullite castable transition layer, and a nanoporous heat insulation board insulation layer from the inside out. A diffusion-type multi-stage burner group 4 is installed at the bottom of furnace body 2. The burner flame pattern can be adjusted by a swirler, supporting a flat flame mode (for the initial melting stage) and a swirling flame mode (for the rapid melting stage).

[0022] Furthermore, oxygen supply pipeline 305 connects liquid oxygen storage tank 302 to VPSA oxygen generator 303, forming a Y-shaped oxygen supply pipeline. A flame arrester and a dynamic pressure balancing valve are installed inside the pipeline. The flame arrester is a stainless steel corrugated structure with a pressure resistance of 1.6 MPa; the opening of the dynamic pressure balancing valve is adjusted in real time by the controller using a PID algorithm, controlling oxygen pressure fluctuations within ±2% based on feedback signals from pipeline pressure sensor 306.

[0023] Furthermore, the inner wall of furnace body 2 is equipped with a water-cooled observation window, and an infrared thermal imager is installed on the outside of the window. The water-cooled observation window is made of sapphire glass, 20 mm thick, and can withstand high-temperature radiation. The infrared thermal imager uses a short-wave infrared sensor (wavelength 1.5-2 micrometers), which can monitor the surface temperature distribution of the molten pool (resolution 640×480 pixels, temperature measurement range 600-2000°C).

[0024] The workflow of this utility model is as follows:

[0025] When the system starts up, the VPSA oxygen generator 303 is turned on first. After the oxygen purity reaches 93%, the vaporizer 304 of the liquid oxygen storage tank 302 is started. The controller ignites the burner group 4 according to the preset program, with the initial power set to 30% and operating in flat flame mode.

[0026] After the aluminum ingots are fed into furnace body 2, an infrared thermal imager detects the local temperature of the molten pool. When the temperature exceeds 600°C, the controller switches the burner to swirling flame mode, increasing the power to 80%. Simultaneously, the dynamic pressure balancing valve adjusts the oxygen flow rate to stabilize the oxygen-to-natural gas ratio at 1.98:1. The flue gas generated by combustion enters the exhaust gas treatment box 301, where, after cyclone dust removal and activated carbon adsorption, the carbon monoxide concentration is reduced to below 50 ppm.

[0027] When the aluminum melt temperature reaches 750°C, the burner power is reduced to 40% to maintain the temperature. Carbon dioxide in the high-temperature flue gas is introduced into the amine absorption tower through a bypass pipe, with a capture rate of not less than 90%. After smelting, the system starts a nitrogen purging procedure to reduce the oxygen concentration in the furnace to below 3%.

[0028] This utility model is a natural gas melting furnace for aluminum ingot melting. Through the synergistic design of all-oxygen combustion technology and gradient refractory layer, it significantly improves the melting efficiency of aluminum ingots, while reducing natural gas consumption per ton of aluminum by more than 30% and reducing nitrogen oxide emissions, meeting stringent environmental protection standards. It integrates a dynamic pressure balancing valve and an infrared thermal imager intelligent feedback system to achieve uniform temperature distribution in the molten pool and stable oxygen supply. Combined with a composite refractory layer and modular structure, it extends the equipment's lifespan and has the advantages of high efficiency, low carbon emissions, safety, and intelligence, making it suitable for green manufacturing of high-end aluminum materials.

[0029] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A natural gas melting furnace for melting aluminum ingots, comprising a furnace body (1) and a controller, characterized in that, The main body of the melting furnace (1) includes: The box (3) is equipped with an exhaust gas treatment box (301), a liquid oxygen storage tank (302) and a VPSA oxygen generator (303). A vaporizer (304) is installed at the bottom of the liquid oxygen storage tank (302), and a handle and a filling port are installed at the top of the liquid oxygen storage tank (302). The furnace body (2) is installed on one side of the box (3). The outer shell of the furnace body (2) is made of gradient refractory layer. The bottom of the furnace body (2) is equipped with a burner group (4). The burner group (4) is a diffusion multi-stage burner group (4). The nozzle of the burner group (4) is made of water-cooled high-temperature resistant alloy, and its flame pattern is adjustable.

2. The natural gas melting furnace for melting aluminum ingots according to claim 1, characterized in that, Both the liquid oxygen storage tank (302) and the VPSA oxygen generator (303) are connected to an oxygen supply pipeline (305). The oxygen supply pipeline (305) is Y-shaped, and a pipeline pressure sensor (306) is installed inside the oxygen supply pipeline (305).

3. The natural gas melting furnace for melting aluminum ingots according to claim 2, characterized in that, The oxygen supply pipeline (305) is equipped with a flame arrester and a dynamic pressure balancing valve. The opening degree of the dynamic pressure balancing valve is controlled in real time by the pipeline pressure sensor (306) and the controller.

4. The natural gas melting furnace for melting aluminum ingots according to claim 1, characterized in that, The inner wall of the furnace body (2) is provided with a water-cooled observation window. An infrared thermal imager is installed on the outside of the water-cooled observation window to monitor the surface temperature distribution of the molten pool. The infrared thermal imager is connected to the controller signal to dynamically adjust the burner power.

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