Roasting vertical kiln with external heating chamber for heating air by using green electricity

Abstract

The utility model relates to a roasting shaft kiln with an external heating chamber for heating air by using green electricity. The roasting shaft kiln comprises a shaft kiln, the external heating chamber, a Roots blower, a dust remover, a smoke exhaust induced draft fan and a chimney, an external heating chamber is arranged on one side of the shaft kiln, the lower portion of the external heating chamber is communicated with the top of a cooling zone of the shaft kiln through a medium-temperature hot air guide-in structure, and the upper portion of the external heating chamber is communicated with the bottom of a roasting zone of the shaft kiln through a high-temperature hot air guide-out structure. And the external heating chamber is provided with a plurality of electric heating devices. Green electricity is adopted to heat air to provide a heat source for the roasting zone of the vertical kiln, so that the production cost is reduced, and energy conservation and environmental protection are realized; the electric heating devices are arranged on the top and the outer wall of the external heating chamber, air is led in from the lower portion of the heating chamber and led out from the upper portion of the heating chamber, materials in the roasting zone are heated more evenly after high-temperature air is adopted for heating, the roasting temperature can be accurately controlled, and the quality of roasted products is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial furnaces, in particular to a vertical furnace with an external heating chamber that heats air using green electricity. Background Art

[0002] Industrial furnaces refer to thermal equipment used in industrial production to smelt, melt, roast (calcine), heat, dry distill, and gasify materials or workpieces using heat generated by fuel combustion or electrical energy conversion. These include eight categories: smelting furnaces, melting furnaces, roasting (calcine) furnaces (kilns), heating furnaces, heat treatment furnaces, drying furnaces (kilns), coke ovens, and gasifiers. Industrial furnaces are widely used in industries such as steel, coking, nonferrous metals, building materials, petrochemicals, chemicals, and machinery manufacturing, playing a vital role in supporting industrial development.

[0003] Currently, industrial furnaces and kilns mostly use non-renewable energy sources such as gas fuels or fossil energy. For example, vertical kilns for roasting ore (such as magnesite and limestone) operate on the countercurrent heat transfer principle. This means that the material in the kiln moves from top to bottom, while the high-temperature flue gas generated by the burning fuel passes through the entire material column from bottom to top. The material is preheated, calcined, and cooled in the kiln before being discharged. Based on the fuel used, they can be divided into coke shaft kilns, coal shaft kilns, oil shaft kilns, and gas shaft kilns. These kilns, which use solid, liquid, or gaseous fuels, produce large amounts of harmful gases (such as CO2 and SO2) after combustion, which are the main source of atmospheric pollution in the industrial sector. To achieve standard flue gas emissions, flue gas treatment equipment is usually required, which increases production costs. Therefore, the use of green energy (such as electricity) as a heat source has gradually become a development trend in industrial furnaces.

[0004] A Chinese utility model patent, granted with publication number CN 207738663 U, discloses an "electrically heated vertical kiln," comprising a vertical kiln divided from top to bottom into a preheating zone, a calcining zone, and a cooling zone. The kiln is equipped with a hopper and exhaust system at the top, and a water-cooled discharge system at the bottom. Electric heating elements are evenly arranged circumferentially and vertically within the kiln walls of the calcining zone. Heating elements on the same cross-section are connected in series to form a group of heating units. Heating elements in adjacent heating units along the height are staggered, and each heating element within a group is separated by a refractory brick partition. Silicon carbide plates are installed on the kiln walls inside the electric heating elements, and a refractory layer is provided between the kiln walls outside the electric heating elements and the kiln shell. In this electrically heated vertical kiln, the electric heating elements are directly installed on the kiln walls of the calcining zone. While this kiln can heat the material, the heat received by the material at the edges and the center of the cross-section differs significantly, resulting in uneven heating. Materials such as limestone require stable temperature support during calcination to ensure calcination uniformity. If the temperature difference is large, it will directly affect the product yield. Summary of the Invention

[0005] The utility model provides a vertical kiln for baking in an external heating chamber which uses green electricity to heat air. The green electricity is used to heat the air to provide a heat source for the baking zone of the vertical kiln, which is beneficial to reducing production costs and being energy-saving and environmentally friendly. Electric heating devices are provided on the top and outer wall of the external heating chamber, and air is introduced from the lower part and discharged from the upper part of the heating chamber. After being heated by high-temperature air, the material in the baking zone is heated more evenly, and the baking temperature can be accurately controlled, thereby effectively improving the quality of the baked products.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A vertical kiln with an external heating chamber for heating air with green electricity comprises a vertical kiln, an external heating chamber, a Roots blower, a dust collector, a smoke exhaust fan and a chimney; the vertical kiln comprises a preheating zone, a roasting zone and a cooling zone from top to bottom, a material inlet is provided at the top of the vertical kiln, and a material outlet is provided at the bottom; an external heating chamber is provided on one side of the vertical kiln, the lower part of the external heating chamber is connected to the top of the cooling zone of the vertical kiln via a medium-temperature hot air inlet structure, and the upper part of the external heating chamber is connected to the bottom of the roasting zone of the vertical kiln via a high-temperature hot air outlet structure; a low-temperature air outlet is provided on one side of the top of the vertical kiln, which is connected in sequence to the dust collector, the smoke exhaust fan and the chimney through a low-temperature air duct; a cooling air inlet is provided on one side of the bottom of the vertical kiln, which is connected to the Roots blower through a cooling air duct; a plurality of electric heating devices are provided in the external heating chamber, and a temperature controller is provided on the line connecting the electric heating device and the power supply; a temperature measuring device is provided in the roasting zone, and the temperature measuring device is interlocked with the temperature controller for control.

[0008] The inner wall of the external heating chamber is shared with the kiln wall of the vertical kiln. An electric heating device is arranged on the outer wall of the external heating chamber. The electric heating device is a silicon carbon rod and is evenly arranged in the vertical and horizontal directions.

[0009] The top wall of the external heating chamber is also provided with an electric heating device.

[0010] The external heating chamber is built with refractory bricks or refractory castable blocks, and a thermal insulation layer is provided on the outer side of the chamber wall; the vertical kiln and the external heating chamber are supported by the same base; a conical discharge hopper is provided at the material outlet at the bottom of the vertical kiln, which is connected to the collection hopper through a discharger; a dust outlet is provided at the bottom of the external heating chamber, which is connected to the collection hopper through a conical dust collection hopper.

[0011] A cooling air distribution device is provided at the bottom of the vertical kiln above the material outlet, and a cooling air inlet of the cooling air distribution device is connected to a cooling air inlet.

[0012] The medium-temperature hot air introduction structure consists of an air collecting hood and a medium-temperature hot air duct. The air collecting hood is arranged in the vertical kiln chamber of the cooling zone, and one side of the air collecting hood is connected to the external heating chamber through the medium-temperature hot air duct.

[0013] The high-temperature hot air outlet structure consists of a high-temperature hot air duct and a high-temperature air hood; the high-temperature air hood is arranged in the vertical kiln chamber at the bottom of the roasting zone, and the bottom of the high-temperature air hood is connected to the external heating chamber through the high-temperature hot air duct. A plurality of high-temperature hot air outlets are arranged along the circumference at the connection between the high-temperature air hood and the high-temperature hot air duct.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1) Compared with conventional vertical kilns that use flue gas from fuel combustion as a heat source, the vertical kiln with an external heating chamber of the utility model uses green electricity to heat air to provide a heat source for the vertical kiln's roasting zone. No toxic or harmful gases are emitted during the roasting process, and environmental protection requirements can be met without the need for additional flue gas treatment equipment, thereby reducing production costs and achieving energy conservation and environmental protection.

[0016] 2) Electric heating devices are installed on the top and outer wall of the external heating chamber. Air is introduced from the bottom of the heating chamber and discharged from the top. After heating with high-temperature air, the materials in the roasting zone are heated more evenly, and the roasting temperature can be accurately controlled, effectively improving the quality of the roasted products. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a vertical furnace for roasting with an external heating chamber that uses green electricity to heat air, as described in the utility model.

[0018] In the figure: 1-external heating chamber; 2-silicon carbon rod; 3-temperature controller; 4-low-temperature air exhaust port; 5-vertical kiln; 6-thermocouple; 7-roasting belt; 8-medium-temperature hot air inlet structure; 9-cooling air inlet; 10-Roots blower; 11-dust collector; 12-exhaust fan; 13-chimney; 14-upper hopper; 15-lower hopper; 16-kiln top silo; 17-discharger; 18-high-temperature hot air outlet structure; 19-power supply; 20-collecting hopper. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0020] like Figure 1As shown, the utility model discloses a vertical kiln with an external heating chamber for heating air with green electricity, comprising a vertical kiln 5, an external heating chamber 1, a roots blower 10, a dust collector 11, a smoke exhaust fan 12 and a chimney 13; the vertical kiln 5 comprises a preheating zone, a roasting zone and a cooling zone from top to bottom, a material inlet is provided at the top of the vertical kiln 5, and a material outlet is provided at the bottom; an external heating chamber 1 is provided on one side of the vertical kiln 5, the lower part of the external heating chamber 1 is connected to the top of the cooling zone of the vertical kiln 5 through a medium-temperature hot air inlet structure 8, and the upper part of the external heating chamber 1 is connected to the cooling zone of the vertical kiln 5 through a medium-temperature hot air inlet structure 8. An overheated hot air outlet structure 18 is connected to the bottom of the roasting zone 7 of the vertical kiln 5; a low-temperature air outlet 4 is provided on one side of the top of the vertical kiln 5, which is connected in sequence to a dust collector 11, a smoke exhaust fan 12 and a chimney 13 through a low-temperature air duct; a cooling air inlet 9 is provided on one side of the bottom of the vertical kiln 5, which is connected to a Roots blower 10 through a cooling air duct; the external heating chamber 1 is provided with multiple electric heating devices, and a temperature controller 3 is provided on the line connecting the electric heating devices to the power supply 19; a temperature measuring device is provided on the roasting zone 7, and the temperature measuring device is interlocked with the temperature controller 3 for control.

[0021] The inner wall of the external heating chamber 1 is shared with the kiln wall of the vertical kiln 5. An electric heating device is provided on the outer wall of the external heating chamber 1. The electric heating device is a silicon carbon rod 2, which is evenly arranged in the vertical and horizontal directions.

[0022] The top wall of the external heating chamber 1 is also provided with an electric heating device.

[0023] The external heating chamber 1 is built with refractory bricks or refractory castable blocks, and a thermal insulation layer is provided on the outer side of the chamber wall; the vertical kiln 5 and the external heating chamber 1 are supported by the same base; a conical discharge hopper is provided at the material outlet at the bottom of the vertical kiln 5, which is connected to the collection hopper 20 through a discharger 17; a dust outlet is provided at the bottom of the external heating chamber 1, which is connected to the collection hopper 20 through a conical dust collection hopper.

[0024] A cooling air distribution device is provided at the bottom of the vertical kiln 5 above the material outlet, and a cooling air inlet of the cooling air distribution device is connected to a cooling air inlet 9 .

[0025] The medium-temperature hot air introduction structure 8 consists of an air collecting hood and a medium-temperature hot air duct. The air collecting hood is arranged in the kiln chamber of the vertical kiln 5 in the cooling zone, and one side of the air collecting hood is connected to the external heating chamber 1 through the medium-temperature hot air duct.

[0026] The high-temperature hot air outlet structure 18 consists of a high-temperature hot air duct and a high-temperature air hood; the high-temperature air hood is arranged in the kiln chamber of the vertical kiln 5 at the bottom of the roasting zone 7, and the bottom of the high-temperature air hood is connected to the external heating chamber through the high-temperature hot air duct. A plurality of high-temperature hot air outlets are arranged along the circumference at the connection between the high-temperature air hood and the high-temperature hot air duct.

[0027] The utility model relates to a vertical kiln for roasting ore (magnesite, limestone, etc.). An external heating chamber 1 is disposed outside the vertical kiln 5. This chamber is equipped with an electric heater (preferably a silicon carbon rod 2). Green electricity is used to heat medium-temperature hot air introduced from the lower portion of the vertical kiln 5 into the external heating chamber 1. The heated hot air is then directed back into the roasting section of the vertical kiln 5 as a heat source for roasting the ore. The electric heater is configured according to process requirements, and a temperature measuring device (preferably a thermocouple 6) is interlocked with a temperature controller 3 to control the temperature of the hot air entering the roasting section 7, thereby achieving precise control of the material roasting temperature.

[0028] The heating power of the electric heating device (such as the silicon carbon rod 2) is adjustable; the cooling air supply device adopts a Roots blower 10, which is a variable frequency blower with adjustable air volume.

[0029] The medium temperature hot air introduction structure 8 can be made of steel structure or refractory material, and the high temperature hot air outlet structure 18 is made of refractory material. The medium temperature hot air introduction structure 8 and the high temperature hot air outlet structure 18 are both fixed in the shaft kiln 5 by corresponding steel structure brackets.

[0030] The following examples are implemented under the premise of the technical solution of the present utility model, and provide detailed implementation methods and specific operating processes, but the scope of protection of the present utility model is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0031] [Example]

[0032] like Figure 1 As shown, in this embodiment, a vertical furnace kiln with an external heating chamber for heating air with green electricity includes a vertical kiln 5, an external heating chamber 1, a silicon carbon rod 2, a temperature controller 3, a thermocouple 6, a medium-temperature hot air outlet structure 8, a high-temperature hot air inlet structure 18, a Roots blower 10, a dust collector 11, a smoke exhaust fan 12, a chimney, etc.

[0033] An external heating chamber 1 is connected to the wall of the vertical kiln 5. Multiple silicon carbide rods 2 are installed on the outer wall of the external heating chamber 1. The temperature of the silicon carbide rods 2 is controlled and regulated by a temperature controller 3. A high-temperature hot air outlet structure 18 made of refractory material is installed between the upper portion of the vertical kiln 5 and the external heating chamber 1. A medium-temperature hot air inlet structure 8 made of steel is installed between the lower portion of the vertical kiln 5 and the external heating chamber 1. A cooling air inlet 9 is installed on one side of the bottom of the vertical kiln 5, connected to a Roots blower 10 via a cooling air duct. A low-temperature air outlet 4 is installed on the top side of the vertical kiln 5, which is connected in sequence to a dust collector 11, a smoke exhaust fan 12, and a chimney via a low-temperature air duct.

[0034] The materials enter the vertical kiln 5 from the upper hopper 14, the lower hopper 15 and the kiln top silo 16 above the vertical kiln 5 in sequence, and are discharged from the material outlet through the discharger 17 and the collecting hopper 20 after being preheated, roasted and cooled. The external heating chamber 1 is connected to the kiln wall of the vertical kiln 5. The cooling air supplied from the bottom of the vertical kiln 2 by the Roots blower 10 enters the vertical kiln 5, exchanges heat with the material in the cooling section to cool the material. A part of the medium-temperature hot air after heat exchange continues to move upward along the vertical kiln 5 to exchange heat with the material, and the other part is collected by the gas collecting hood and enters the external heating chamber 1 through the medium-temperature hot air inlet structure 8; a plurality of silicon carbide rods 2 are set on the outer wall and top wall of the external heating chamber 1 to heat the medium-temperature hot air entering the external heating chamber 1. The heated high-temperature hot air then enters the roasting section 7 of the vertical kiln 5 through the high-temperature hot air outlet structure 18 to increase the heat for the roasting of the material; a thermocouple 6 is set in the roasting section 7 to detect the real-time temperature, and the power of the silicon carbide rod 2 is adjusted by the temperature controller 3 to ensure that the temperature of the high-temperature hot air entering the roasting section 7 is between 1250 and 1350°C, and the pressure of the high-temperature hot air is between -100 and 20Pa. The high-temperature hot air enters the roasting section 7, exchanges heat with the material, and then enters the preheating section. After further heat exchange with the material in the preheating section, the low-temperature air is discharged from the shaft kiln 5 through the low-temperature air outlet 4. After dust removal by the dust collector 11, it is discharged into the chimney by the exhaust fan 12. Dust in the external heating chamber 1 falls to the bottom, is discharged from the dust outlet through the conical dust hopper, and is then sent to the collection hopper 20.

[0035] In this embodiment, the production capacity of the vertical kiln 5 is 50 tons / day, the heat consumption is 900-1000 kcal / kg finished product, and the maximum air supply volume of the Roots blower 10 is 100m 3 / min, the external dimensions of the external heating chamber 1 are 3500 mm (height) × 800 mm (length) × 800 mm (width).

[0036] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vertical furnace with an external heating chamber that heats air with green electricity, characterized in that: The invention comprises a vertical kiln, an external heating chamber, a Roots blower, a dust collector, an exhaust fan and a chimney; the vertical kiln comprises a preheating zone, a roasting zone and a cooling zone from top to bottom, a material inlet is provided at the top of the vertical kiln and a material outlet is provided at the bottom; an external heating chamber is provided on one side of the vertical kiln, the lower part of the external heating chamber is connected to the top of the cooling zone of the vertical kiln through a medium-temperature hot air inlet structure, and the upper part of the external heating chamber is connected to the bottom of the roasting zone of the vertical kiln through a high-temperature hot air outlet structure; a low-temperature air outlet is provided on one side of the top of the vertical kiln, which is connected in sequence to the dust collector, the exhaust fan and the chimney through a low-temperature air duct; a cooling air inlet is provided on one side of the bottom of the vertical kiln, which is connected to the Roots blower through a cooling air duct; a plurality of electric heating devices are provided in the external heating chamber, and a temperature controller is provided on the line connecting the electric heating device and the power supply; a temperature measuring device is provided in the roasting zone, and the temperature measuring device is interlocked with the temperature controller for control.

2. The vertical furnace kiln with an external heating chamber for heating air with green electricity according to claim 1, characterized in that: The inner wall of the external heating chamber is shared with the kiln wall of the vertical kiln. An electric heating device is arranged on the outer wall of the external heating chamber. The electric heating device is a silicon carbon rod and is evenly arranged in the vertical and horizontal directions.

3. The vertical furnace with an external heating chamber for heating air with green electricity according to claim 2, characterized in that: The top wall of the external heating chamber is also provided with an electric heating device.

4. A vertical furnace with an external heating chamber for heating air with green electricity according to claim 1, 2 or 3, characterized in that: The external heating chamber is built with refractory bricks or refractory castable blocks, and a thermal insulation layer is provided on the outer side of the chamber wall; the vertical kiln and the external heating chamber are supported by the same base; a conical discharge hopper is provided at the material outlet at the bottom of the vertical kiln, which is connected to the collection hopper through a discharger; a dust outlet is provided at the bottom of the external heating chamber, which is connected to the collection hopper through a conical dust collection hopper.

5. The vertical furnace with an external heating chamber for heating air with green electricity according to claim 1, characterized in that: A cooling air distribution device is provided at the bottom of the vertical kiln above the material outlet, and a cooling air inlet of the cooling air distribution device is connected to a cooling air inlet.

6. The vertical furnace with an external heating chamber for heating air with green electricity according to claim 1, characterized in that: The medium-temperature hot air introduction structure consists of an air collecting hood and a medium-temperature hot air duct. The air collecting hood is arranged in the vertical kiln chamber of the cooling zone, and one side of the air collecting hood is connected to the external heating chamber through the medium-temperature hot air duct.

7. The vertical furnace with an external heating chamber for heating air with green electricity according to claim 1, characterized in that: The high-temperature hot air outlet structure consists of a high-temperature hot air duct and a high-temperature air hood; the high-temperature air hood is arranged in the vertical kiln chamber at the bottom of the roasting zone, and the bottom of the high-temperature air hood is connected to the external heating chamber through the high-temperature hot air duct. A plurality of high-temperature hot air outlets are arranged along the circumference at the connection between the high-temperature air hood and the high-temperature hot air duct.

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