A high-efficiency multi-layer and multi-row atmosphere-protected roller kiln

Abstract

The present invention provides a high-efficiency multi-layer multi-row atmosphere protection roller kiln, including a heating section and a cooling section. The first air inlet pipe is provided at the top, bottom and both sides of the furnace cavity of the heating section. The top and bottom of the furnace cavity of the heating section are respectively provided with exhaust gas outlets for extracting the exhaust gas in the furnace cavity. The furnace cavity of the cooling section adopts interlayer air cooling and fin heat exchange tube cooling at the same time. The interlayer air cooling is achieved by air flowing through the cold air inlet and the hot air outlet. The fin heat exchange tube runs through the furnace cavity, and a cooling medium is introduced into the fin heat exchange tube. The present invention ensures that each layer of sagger is fully exposed to oxygen, thereby improving the qualified rate; allowing oxygen to continuously enter the sagger and fully react with the product; preheating the oxygen before entering to avoid the introduction of normal temperature oxygen causing too large a temperature difference in the kiln cross section, thereby affecting the product quality; reducing the overall energy consumption; shortening the cooling time of the product, and improving the quality of the finished product.

Description

Technical Field

[0001] The invention relates to the technical field of roller kilns, in particular to a high-efficiency multi-layer multi-row atmosphere-protected roller kiln. Background Art

[0002] In recent years, with the increasing awareness of environmental protection and the intensification of the energy crisis, the development and application of new energy sources have become the focus of domestic attention. With the strong support of the country, lithium-ion batteries have ushered in explosive growth. Reaction sintering process is a key link in the production of lithium-ion battery materials. Reaction sintering equipment was originally mainly push-plate channel furnaces and rotary furnaces. As the production of lithium battery materials has entered a large-scale, continuous operation, sintering roller kilns have replaced other types of kilns.

[0003] The sintering roller kiln has a flat furnace bottom composed of several SIC rollers. The rollers rotate continuously under the drive of the power source. An exhaust pipe is set on the top to discharge the exhaust gas through the exhaust fan. Air or oxygen is introduced into the bottom through the blower. Multiple rows of saggers for placing products move slowly and continuously on the rollers, completing the preheating, calcining and cooling process of the products in the process of moving from the kiln head to the kiln tail.

[0004] At present, the sintering roller kilns used by lithium battery ternary material manufacturers are generally double-layer 4-row and single-layer 6-row. In order to increase production and reduce the unit energy consumption of materials, the saggers can only be stacked up to three or even four layers. Since the heating method of the roller kiln is up and down heating, the increase in the number of saggers will inevitably lead to uneven temperature of the calcined materials. At present, if the saggers of the roller kiln are more than three layers, the material inside will heat up much slower than the material on the surface, which will lead to inconsistent performance of the internal and external materials and reduce the quality of batch products.

[0005] The calcination process of ternary materials produces a lot of waste gas and consumes a lot of oxygen. The current roller kilns are designed with exhaust systems at the top and air intake systems at the bottom to meet the calcination requirements. This design cannot meet the calcination requirements of materials above three layers.

[0006] In order to ensure that the temperature of the product out of the kiln is not too high, air-cooled interlayer cooling is generally used in the cooling section of the kiln. When the number of saggers is greater than 3, it is difficult to cool the product in the bottom sagger only by using air-cooled interlayer cooling, and the temperature out of the kiln will be too high. Summary of the invention

[0007] In view of the above problems, the present invention provides a high-efficiency multi-layer and multi-row atmosphere-protected roller kiln, which ensures that each layer of saggers is fully exposed to oxygen, ensures normal reaction of products in the furnace, and improves the qualified rate; allows oxygen to continuously enter the saggers and fully react with the products; preheats the oxygen before entering the heating section to avoid too large temperature difference in the kiln cross section caused by the introduction of normal temperature oxygen, thereby affecting product quality; reduces overall energy consumption; shortens the cooling time of products, ensures that the products out of the furnace are cooled to the appropriate temperature in time, and improves the quality of the finished products.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A high-efficiency multi-layer and multi-row atmosphere-protected roller kiln comprises a heating section and a cooling section. First air inlet pipes are arranged on the top, bottom and both sides of the furnace chamber of the heating section, wherein the first air inlet pipes on both sides face the sagger. Exhaust gas outlets are respectively arranged on the top and bottom of the furnace chamber of the heating section for extracting exhaust gas from the furnace chamber. The furnace chamber of the cooling section adopts interlayer air cooling and fin heat exchange tube cooling at the same time. The top and bottom of the furnace chamber of the cooling section are respectively provided with connected cold air inlet and hot air outlet. The interlayer air cooling is achieved by air flowing through the cold air inlet and the hot air outlet. The fin heat exchange tube cooling is achieved by heat exchange through fin heat exchange tubes arranged on and below the sagger. The fin heat exchange tube runs through the furnace chamber, and a cooling medium is introduced into the fin heat exchange tube.

[0010] Preferably, a plurality of interlayers are provided at intervals above and below the furnace cavity of the cooling section, and each interlayer is provided with the cold air inlet and the hot air outlet.

[0011] Preferably, three or more layers of saggers are placed in the roller kiln.

[0012] Preferably, the protective gas introduced into the first air inlet pipe of the temperature rising section is preheated.

[0013] Preferably, the cooling medium heated by the finned heat exchange tube is used to preheat the protective gas before it is introduced into the furnace chamber.

[0014] Preferably, the bottom and both sides of the furnace chamber of the cooling section are provided with second air inlet pipes for introducing protective gas, and the height of the second air inlet pipes located on the two sides is higher than the sagger at the top.

[0015] Preferably, the protective gas is oxygen.

[0016] Beneficial effects of the present invention:

[0017] 1. The first air inlet pipe is installed at the top, bottom and both sides of the furnace chamber in the heating stage to supply oxygen, ensuring that each layer of saggers is fully exposed to oxygen, ensuring the normal reaction of the products in the furnace and improving the qualified rate;

[0018] 2. During the heating stage, exhaust gas is extracted from both the upper and lower parts of the furnace cavity to ensure that the kiln pressure is not too high. This solves the problem of increasing the kiln pressure by increasing the top suction force of conventional kilns, so that oxygen can continue to enter the sagger and fully react with the product;

[0019] 3. Preheat the oxygen before it enters the heating section to avoid excessive temperature difference in the kiln section caused by the oxygen at room temperature, which would affect product quality.

[0020] 4. The cooling coal after heat exchange is used to heat the oxygen before it enters the furnace cavity of the heating section, making full use of the heat of the cooling coal and reducing overall energy consumption.

[0021] 5. The furnace cavity of the cooling section adopts interlayer air cooling and fin heat exchange tube cooling at the same time to improve heat exchange efficiency, shorten product cooling time, ensure that the products out of the oven are cooled to the appropriate temperature in time, and improve the quality of the finished products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a front view of the present invention;

[0023] Figure 2 is a cross-sectional view of a cooling section of the present invention;

[0024] Figure 3 It is a front view of a section of the interlayer length of the cooling section of the present invention;

[0025] Figure 4 It is a cross-sectional view of the temperature rising section of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is described below in conjunction with the accompanying drawings and embodiments.

[0027] like Figures 1 to 4 As shown, the high-efficiency multi-layer multi-row atmosphere protection roller kiln described in the present invention includes a heating section and a cooling section, the heating section is in front and the cooling section is in the back, the sagger 1 in the kiln moves on the top of the roller 2, and the sagger 1 is placed with products. In this embodiment, three or more layers of saggers 1 are placed in the roller kiln, and the first air inlet pipe 3 is provided at the top, bottom and both sides of the furnace cavity of the heating section. Oxygen is introduced into the first air inlet pipe 3, and the first air inlet pipe 3 on both sides is facing the sagger 1, so that each layer of the sagger 1 can be ensured to have sufficient oxygen for reaction. The top and bottom of the furnace cavity of the heating section are respectively provided with exhaust gas outlets 4 for extracting the exhaust gas in the furnace cavity, so that there is no need to increase the suction force of the exhaust fan at the top of the furnace cavity, thereby ensuring that the pressure in the kiln is not too low, and the exhaust gas can be extracted in time to ensure the normal reaction of the product.

[0028] Specifically, the furnace cavity of the cooling section adopts interlayer air cooling and fin heat exchange tube cooling at the same time. The top and bottom of the furnace cavity of the cooling section are respectively provided with interlayers, and there is an independent interlayer at every certain interval. A connected cold air inlet 5 and a hot air outlet 6 are provided in the interlayer. The cold air inlet 5 located above the furnace cavity of the cooling section is connected to the cold air outlet 6 located above, and the cold air inlet 5 located below the furnace cavity of the cooling section is connected to the cold air outlet 6 located below. Cold air is introduced into the furnace cavity from the cold air inlet 5. After the cold air exchanges heat with the furnace cavity and the product on the sagger 1, the cold air is heated and then discharged from the hot air outlet 6. The interlayer air cooling is achieved by the air flowing through the cold air inlet 5 and the hot air outlet 6. The finned heat exchange tube cooling is heat exchanged through the finned heat exchange tube 7 arranged on the upper and lower sides of the sagger 1. The finned heat exchange tube 7 runs through the furnace cavity. The cooling medium is introduced into the finned heat exchange tube 7. The cooling coal enters the finned heat exchange tube 7 and exchanges heat with the gas in the furnace cavity in the furnace cavity, thereby reducing the furnace temperature. The cooling medium after heat exchange and temperature rise from the finned heat exchange tube 7 is used to preheat the protective gas before entering the furnace cavity. Here, a heat exchanger can be used to transfer the heat of the cooling coal to oxygen, so that the oxygen entering the heating section is preheated and will not reduce the furnace temperature too much, ensuring the normal reaction of the product in the furnace and ensuring the qualified rate. The bottom and both sides of the furnace cavity of the cooling section are provided with a second air inlet pipe 8 to introduce protective gas. The protective gas here is oxygen. The height of the second air inlet pipe 8 located on both sides is higher than the top sagger 1, and an exhaust gas discharge port 9 is provided above the furnace cavity to discharge the exhaust gas in the furnace cavity.

[0029] The present invention is provided with a first air inlet pipe 3 at the top, bottom and both sides of the furnace chamber in the heating section for oxygen supply, ensuring that each layer of the sagger 1 is fully exposed to oxygen, ensuring the normal reaction of the product in the furnace, and improving the qualified rate; in the heating section, the exhaust gas is extracted from the upper and lower parts of the furnace chamber at the same time to ensure that the kiln pressure is not too high, solving the problem of increasing the influence of the conventional kiln furnace on the kiln pressure by increasing the top suction force, so that oxygen can continue to enter the sagger 1 and fully react with the product; the oxygen before entering the heating section is preheated first to avoid the oxygen introduced lowering the furnace temperature and affecting the product quality; the cooling coal after heat exchange is used to heat the oxygen before entering the furnace chamber of the heating section, making full use of the heat of the cooling coal and reducing the overall energy consumption. The furnace chamber of the cooling section adopts interlayer air cooling and fin heat exchange tube 7 cooling at the same time to improve the heat exchange efficiency, shorten the cooling time of the product, ensure that the products out of the furnace are timely reduced to the appropriate temperature, and improve the quality of the finished product.

[0030] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, and a specific direction structure and operation, and therefore, cannot be understood as a limitation of the present invention. In addition, "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A high-efficiency multi-layer multi-row atmosphere protection roller kiln, characterized in that: The kiln comprises a heating section and a cooling section, wherein the heating section is in front and the cooling section is in the back. The sagger in the kiln moves on the top of the rollers, and the products are placed in the sagger. Three or more layers of saggers are placed in the roller kiln. The top, bottom and both sides of the furnace cavity of the heating section are provided with first air inlet pipes, and oxygen is introduced into the first air inlet pipes. The top and bottom of the furnace cavity of the heating section are respectively provided with exhaust gas outlets for extracting the exhaust gas in the furnace cavity, so that there is no need to increase the suction force of the exhaust fan at the top of the furnace cavity, thereby ensuring that the pressure in the kiln is not too low, and the exhaust gas can be extracted in time to ensure the normal reaction of the product. The furnace cavity of the cooling section adopts interlayer air cooling and fin heat exchange tube cooling at the same time. The furnace cavity of the cooling section is respectively provided with interlayers at the top and the bottom, and a cold air inlet and a hot air outlet are provided in the interlayers. The cold air inlet located above the furnace cavity of the cooling section is connected with the cold air outlet located above, and the cold air inlet located below the furnace cavity of the cooling section is connected with the cold air outlet located below. Cold air is introduced from the cold air inlet, and after the cold air exchanges heat with the furnace cavity and the products on the sagger, the cold air is heated and discharged from the hot air outlet. The fin heat exchange tube cooling exchanges heat through the fin heat exchange tubes arranged on and below the sagger, and the fin heat exchange tubes run through the furnace cavity. A cooling medium is introduced into the fin heat exchange tubes, and the cooling coal enters the fin heat exchange tubes, exchanges heat with the gas in the furnace cavity in the furnace cavity, thereby reducing the furnace temperature, and the cooling medium heated by heat exchange from the fin heat exchange tubes is used to preheat the protective gas before being introduced into the furnace cavity. The bottom and both sides of the furnace cavity of the cooling section are provided with second air inlet pipes for introducing protective gas, wherein the protective gas is oxygen. The height of the second air inlet pipes located on both sides is higher than the sagger at the top, and an exhaust gas discharge port is provided above the furnace cavity to discharge the exhaust gas in the furnace cavity. A first air inlet pipe is provided at the top, bottom and both sides of the furnace chamber in the heating section for oxygen supply, ensuring that each layer of saggers is fully exposed to oxygen, ensuring normal reaction of the products in the furnace and improving the qualified rate; in the heating section, exhaust gas is extracted from the upper and lower parts of the furnace chamber at the same time to ensure that the kiln pressure is not too high, which solves the problem of increasing the kiln pressure by increasing the top suction force of conventional kilns, so that oxygen can continue to enter the saggers and fully react with the products; the oxygen before entering the heating section is preheated first to avoid the oxygen introduced lowering the furnace temperature and affecting the product quality; the cooling coal after heat exchange is used to heat the oxygen before it is introduced into the furnace chamber of the heating section, making full use of the heat of the cooling coal and reducing the overall energy consumption; the furnace chamber of the cooling section adopts interlayer air cooling and fin heat exchange tube cooling at the same time to improve the heat exchange efficiency, shorten the cooling time of the product, ensure that the products out of the furnace are cooled to the appropriate temperature in time, and improve the quality of the finished product.

2. The high-efficiency multi-layer multi-row atmosphere protection roller kiln according to claim 1 is characterized in that: The first air inlet pipes on both sides face the saggers to ensure that each layer of the saggers has sufficient oxygen for reaction.

3. The high-efficiency multi-layer multi-row atmosphere protection roller kiln according to claim 1, characterized in that: There is an independent mezzanine at every certain distance.

4. The high-efficiency multi-layer multi-row atmosphere protection roller kiln according to claim 1, characterized in that: The interlayer air cooling is achieved by air flowing through the cold air inlet and the hot air outlet.

5. The high-efficiency multi-layer multi-row atmosphere protection roller kiln according to claim 1, characterized in that: The cooling medium heated by heat exchange in the finned heat exchange tube is used to preheat the protective gas before entering the furnace cavity. It transfers the heat of the cooling coal to the oxygen through a heat exchanger. In this way, the oxygen entering the heating section has been preheated and will not lower the furnace temperature too much, thereby ensuring the normal reaction of the product in the furnace and ensuring the qualified rate.

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