A large-scale rotary furnace tail gas waste heat recovery system

Abstract

The utility model discloses a large -scale rotary furnace tail gas waste heat recovery system, including equipment module, gas -solid separation module and air intake combustion module, equipment module is by feeding machine, heating furnace feed bin, heating furnace and heating furnace discharge bin who connects gradually and is composed of, and heating air enters by the heating chamber rear end of heating furnace, and moves to the front end gradient heating to the furnace pipe, gas -solid separation module includes gas -solid separation filter and filter fan, gas -solid separation filter with between heating furnace discharge bin passes through pipeline connection, and filter fan with between gas -solid separation filter passes through pipeline connection, the utility model discloses the synergistic effect of equipment module, gas -solid separation module and air intake combustion module, has realized to the efficient recycling of large -scale rotary furnace tail gas waste heat, gas -solid separation module can effectively separate the solid material in tail gas and combustible gas, both recycle solid material, and utilize combustible tail gas as fuel, reduce energy waste.

Description

Technical Field

[0001] This utility model relates to the field of exhaust gas waste heat recovery technology, specifically a large rotary kiln exhaust gas waste heat recovery system. Background Technology

[0002] In industrial production processes, large rotary kilns, as important thermal equipment, often carry a large amount of unutilized waste heat in their exhaust emissions. If this waste heat is directly released into the environment, it will not only waste energy but may also cause thermal pollution to the surrounding environment. Therefore, this application proposes a waste heat recovery system for large rotary kiln exhaust gases. Utility Model Content

[0003] The purpose of this invention is to provide a waste heat recovery system for large rotary kiln exhaust gas to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a large rotary kiln tail gas waste heat recovery system, comprising an equipment module, a gas-solid separation module, and an inlet combustion module. The equipment module consists of a feeder, a heating furnace feed hopper, a heating furnace, and a heating furnace discharge hopper connected in sequence. Heating air enters from the rear end of the heating chamber of the heating furnace and moves towards the front end to perform gradient heating on the furnace tubes. The gas-solid separation module includes a gas-solid separation filter and a filter fan. The gas-solid separation filter is connected to the heating furnace discharge hopper via a pipeline, and the filter fan is connected to the gas-solid separation filter via a pipeline. The gas-solid separation filter is used to separate solid materials and combustible gases in the exhaust gas. The solid materials fall back to the heating furnace discharge hopper, and the filtered combustible exhaust gas is transported to the air intake combustion module via the filter fan. The air intake combustion module includes an air intake pipe, an exhaust gas outlet pipe, a heat exchange pipe, and a hot air furnace. The filter fan is connected to the hot air furnace via a pipe. The air intake pipe supplies natural gas to the hot air furnace. The hot air furnace is connected to the heat exchange pipe via a pipe. The hot air furnace burns natural gas and combustible exhaust gas to generate hot air, which heats the furnace tubes of the heating furnace. It also recovers the waste heat from the hot air discharged from the heating furnace to preheat the combustion air.

[0005] The hot air furnace adopts a dual-fuel burner structure, including a natural gas inlet pipeline and a combustible exhaust gas inlet pipeline. The external natural gas is connected to the natural gas inlet pipeline through a pipeline, and the hot air discharged from the heating furnace is connected to the combustible exhaust gas inlet pipeline through a pipeline.

[0006] The gas-solid separation filter is externally wound with an auxiliary electric heating wire.

[0007] The heat exchange pipe adopts a spiral coil structure, which is coiled around the outside of the hot blast stove exhaust channel, and uses the waste heat of the exhaust gas from the heating furnace to preheat the combustion air entering the hot blast stove.

[0008] The furnace tube of the heating furnace adopts segmented heating, which is divided into a preheating section, a reaction section and a cooling section along the material travel direction. The temperature range of the preheating section is 300-500℃, the temperature range of the reaction section is 600-800℃ and the temperature range of the cooling section is 200-400℃.

[0009] It also includes: a furnace tube auxiliary heating module, which includes a natural gas pipeline and a temperature compensation burner. The temperature compensation burner is evenly arranged along the furnace tube axis and is used to compensate for the temperature of the furnace tube.

[0010] It also includes: a gas-solid separator insulation module, and a heat tracing air duct for the gas-solid separator insulation module, which connects the hot air furnace to the gas-solid separator to prevent tar condensation inside the gas-solid separator.

[0011] Compared with the prior art, the beneficial effects of this utility model are: This utility model achieves efficient recovery and utilization of waste heat from the tail gas of a large rotary kiln through the coordinated work of the equipment module, the gas-solid separation module and the air intake combustion module; the gas-solid separation module can effectively separate solid materials and combustible gases in the tail gas, thus recovering solid materials and utilizing combustible tail gas as fuel, reducing energy waste. The intake combustion module can burn natural gas and combustible exhaust gas simultaneously, generating enough hot air to heat the furnace tubes of the heating furnace. It also recovers the waste heat of the hot air discharged from the heating furnace through heat exchange pipes to preheat the combustion air, further improving energy utilization efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the waste heat recovery system for the tail gas of a large rotary kiln according to this utility model. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0014] Please see Figure 1 This utility model provides a technical solution: a large rotary kiln tail gas waste heat recovery system, including an equipment module, a gas-solid separation module and an air intake combustion module. Through the coordinated work of the equipment module, the gas-solid separation module and the air intake combustion module, the efficient recovery and utilization of large rotary kiln tail gas waste heat is realized.

[0015] The equipment module consists of a feeder, a heating furnace feed hopper, a heating furnace, and a heating furnace discharge hopper connected in sequence. The heating air enters from the rear end of the heating chamber of the heating furnace and moves towards the front end to perform gradient heating on the furnace tubes. Specifically, the heating air enters from the rear end of the heating chamber of the heating furnace and heats the furnace tubes while moving towards the front end. The temperature also decreases gradually from high to low and is finally discharged from the front end of the heating chamber.

[0016] Furthermore, the feeder transports the material to the heating furnace feed hopper through pipelines, and then the heating furnace feed hopper evenly feeds the material into the furnace tubes of the heating furnace. The material moves slowly forward in the furnace tubes as the furnace tubes rotate, passing through the preheating section, reaction section and cooling section in sequence. In the preheating section, the material is initially heated by heating air to prepare for the subsequent reaction. After entering the reaction section, the material undergoes specific chemical reactions or physical changes. Finally, it reaches the cooling section, where the material gradually cools down and stabilizes, and is finally discharged from the heating furnace discharge hopper.

[0017] The gas-solid separation module includes a gas-solid separation filter and a filter fan. The gas-solid separation filter is connected to the heating furnace discharge hopper via a pipeline, and the filter fan is connected to the gas-solid separation filter via a pipeline. The gas-solid separation filter is used to separate solid materials and combustible gases in the exhaust gas. The solid materials fall back to the heating furnace discharge hopper, and the filtered combustible exhaust gas is transported to the intake combustion module by the filter fan. The gas-solid separation filter separates solid materials and combustible gases in the exhaust gas. After separation, the solid materials fall back to the heating furnace discharge hopper for recycling, increasing the material recovery rate. The filtered exhaust gas is transported to the hot blast stove by the filter fan and used as fuel to heat the heating furnace.

[0018] Specifically, when the gas-solid separation filter is working, its internal filter element can intercept solid particles in the exhaust gas, allowing clean combustible exhaust gas to pass through. The filter fan provides power to ensure that the combustible exhaust gas is delivered to the hot air furnace. When the exhaust gas enters the gas-solid separation filter, larger solid particles fall directly back to the heating furnace discharge hopper due to gravity, while fine particles are intercepted by the filter medium and eventually fall back to the heating furnace discharge hopper as well, thus realizing the recovery of solid materials. The filtered combustible exhaust gas is transported to the filter fan through pipelines, and the filter fan sends the combustible exhaust gas into the hot air furnace to provide fuel for combustion. This not only improves the material recovery rate but also ensures the full utilization of combustible exhaust gas and avoids energy waste.

[0019] The intake combustion module includes an intake pipe, an exhaust pipe, a heat exchange pipe, and a hot air furnace. The filter fan is connected to the hot air furnace via a pipe. The intake pipe supplies natural gas to the hot air furnace. The hot air furnace is connected to the heat exchange pipe via a pipe. The hot air furnace burns natural gas and combustible exhaust gas to generate hot air, which heats the furnace tubes of the heating furnace. It also recovers the waste heat from the hot air discharged from the heating furnace to preheat the combustion air.

[0020] Specifically, after the filter fan delivers the combustible exhaust gas to the hot blast stove, the intake pipe simultaneously supplies natural gas to the stove. The dual-fuel burner inside the stove then operates, simultaneously burning both natural gas and the combustible exhaust gas to generate high-temperature hot air. This high-temperature hot air is then piped to the heating furnace to heat the furnace tubes, ensuring that the materials inside can undergo chemical reactions or physical changes at a suitable temperature. Simultaneously, the hot air discharged from the heating furnace is not directly emitted but undergoes waste heat recovery through heat exchange pipes. These heat exchange pipes employ a spiral coil structure, coiled around the outside of the hot blast stove's exhaust channel, utilizing the waste heat from the furnace's exhaust gas to preheat the combustion air entering the stove. In this way, the combustion air is preheated to a certain temperature before entering the hot blast stove, reducing the stove's energy consumption and further improving energy efficiency. Finally, the exhaust gas, after heat exchange, is discharged from the system through the exhaust gas outlet pipe, completing the entire waste heat recovery process.

[0021] The hot air furnace adopts a dual-fuel burner structure, including a natural gas inlet pipeline and a combustible exhaust gas inlet pipeline. The external natural gas is connected to the natural gas inlet pipeline through a pipeline, and the hot air discharged from the heating furnace is connected to the combustible exhaust gas inlet pipeline through a pipeline.

[0022] Specifically, the hot blast stove adopts a dual-fuel burner structure, enabling it to utilize both natural gas and combustible exhaust gas. During normal production, the mixing ratio of natural gas and combustible exhaust gas can be adjusted according to the content of combustible components in the exhaust gas and production needs. When there are more combustible components in the exhaust gas, the amount of natural gas used can be appropriately reduced, increasing the combustion ratio of combustible exhaust gas and thus reducing production costs. Conversely, when there are fewer combustible components in the exhaust gas, the supply of natural gas is increased to ensure that the hot blast stove can stably generate sufficient high-temperature hot air to meet the heating requirements of the furnace tubes.

[0023] The gas-solid separator is externally wound with auxiliary electric heating wires. The main function of these wires is to heat the gas-solid separator when the ambient temperature is low, preventing tar and other substances in the exhaust gas from condensing inside the filter due to temperature drops. Once tar condenses, it not only clogs the filter element, affecting filtration efficiency, but also increases the difficulty of cleaning and maintenance costs of the gas-solid separator.

[0024] The heat exchange pipe adopts a spiral coil structure, which is coiled around the outside of the hot blast stove exhaust channel, and uses the waste heat of the exhaust gas from the heating furnace to preheat the combustion air entering the hot blast stove.

[0025] The furnace tubes of the heating furnace adopt segmented heating, which is divided into a preheating section, a reaction section and a cooling section along the material travel direction. The temperature range of the preheating section is 300-500℃, the temperature range of the reaction section is 600-800℃ and the temperature range of the cooling section is 200-400℃.

[0026] Specifically, in the preheating section, the material is heated to 300-500℃ to reach a suitable initial reaction temperature, preparing it for subsequent chemical reactions or physical changes. After entering the reaction section, the temperature is raised to 600-800℃. This temperature range can meet the needs of most materials to undergo specific reactions, ensuring that the reaction proceeds fully. Finally, in the cooling section, the temperature drops to 200-400℃, allowing the material to gradually cool and stabilize, preventing product quality from being affected by excessively high or low temperatures.

[0027] It also includes: a furnace tube auxiliary heating module, which includes a natural gas pipeline and a temperature compensation burner. The temperature compensation burner is evenly arranged along the furnace tube axis and is used to compensate for the temperature of the furnace tube.

[0028] Specifically, the supplementary heating burners of the furnace tube auxiliary heating module are evenly distributed along the furnace tube axis, enabling precise temperature supplementation based on the temperature requirements of different locations within the furnace tube. When the temperature in a certain area of ​​the furnace tube is lower than the set range, the corresponding supplementary heating burner can be activated, using natural gas supplied through the natural gas pipeline for combustion heating. This ensures a uniform and stable temperature within the furnace tube, preventing incomplete material reaction or product quality degradation due to excessively low local temperatures.

[0029] It also includes: a gas-solid separator insulation module, a gas-solid separator insulation module heat tracing air duct, and a heat tracing air duct that connects the hot air furnace to the gas-solid separator to prevent tar condensation inside the gas-solid separator.

[0030] Specifically, a portion of the hot air generated by the hot air furnace is introduced into the vicinity of the gas-solid separator through a heated air duct, creating a relatively high-temperature environment. Under such conditions, the temperature inside the gas-solid separator is maintained, effectively preventing condensation of substances such as tar in the exhaust gas due to temperature reduction.

[0031] Working principle: During operation, the feeder first conveys the material to the heating furnace feed hopper, which then evenly feeds the material into the furnace tubes. The material moves slowly forward within the furnace tubes as they rotate, sequentially passing through the preheating section, reaction section, and cooling section. Simultaneously, heating air enters from the rear of the heating chamber and moves towards the front, providing gradient heating to the furnace tubes. In the preheating section, the material is heated to 300-500℃, reaching a suitable initial reaction temperature. Upon entering the reaction section, the temperature rises to 600-800℃, meeting the requirements for the specific reaction and ensuring a complete reaction. Finally, in the cooling section, the temperature drops to 200-400℃, allowing the material to gradually cool and stabilize. The exhaust gas from the heating furnace enters the gas-solid separation module. The gas-solid separation filter separates the solid materials and combustible gases in the exhaust gas. Larger solid particles fall directly back to the heating furnace discharge hopper due to gravity, while finer particles are intercepted by the filter medium and also fall back to the heating furnace discharge hopper. The filtered combustible exhaust gas is transported to the filter fan through the pipeline, and the filter fan sends the combustible exhaust gas into the hot air furnace. Natural gas is supplied to the hot blast stove through its intake pipe. The dual-fuel burner inside the hot blast stove simultaneously burns natural gas and combustible exhaust gas to generate high-temperature hot air. This high-temperature hot air is transported to the heating furnace through pipes to heat the furnace tubes. The hot air discharged from the heating furnace is then discharged through heat exchange pipes for waste heat recovery. These heat exchange pipes are coiled around the outside of the hot blast stove's exhaust channel, using the waste heat from the exhaust gas discharged from the heating furnace to preheat the combustion air entering the hot blast stove. When the temperature in a certain area of ​​the furnace tube is lower than the set range, the heat-compensating burners of the furnace tube auxiliary heating module are turned on, and natural gas supplied through the natural gas pipeline is used for combustion and heating to compensate for the temperature of the furnace tube. At the same time, the accompanying hot air pipes introduce some of the hot air generated by the hot blast stove into the vicinity of the gas-solid separator to prevent tar condensation in the gas-solid separator. Finally, the exhaust gas after heat exchange is discharged through the exhaust gas outlet pipe, completing the entire exhaust gas waste heat recovery process.

[0032] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

Claims

1. A large rotary kiln exhaust gas waste heat recovery system, comprising an equipment module, a gas-solid separation module, and an intake combustion module, characterized in that: The equipment module consists of a feeder, a heating furnace feed hopper, a heating furnace, and a heating furnace discharge hopper connected in sequence. Heating air enters from the rear end of the heating chamber of the heating furnace and moves towards the front end to perform gradient heating on the furnace tubes. The gas-solid separation module includes a gas-solid separation filter and a filter fan. The gas-solid separation filter is connected to the heating furnace discharge hopper via a pipeline, and the filter fan is connected to the gas-solid separation filter via a pipeline. The gas-solid separation filter is used to separate solid materials and combustible gases in the exhaust gas. The solid materials fall back to the heating furnace discharge hopper, and the filtered combustible exhaust gas is transported to the air intake combustion module via the filter fan. The air intake combustion module includes an air intake pipe, an exhaust gas outlet pipe, a heat exchange pipe, and a hot air furnace. The filter fan is connected to the hot air furnace via a pipe. The air intake pipe supplies natural gas to the hot air furnace. The hot air furnace is connected to the heat exchange pipe via a pipe. The hot air furnace burns natural gas and combustible exhaust gas to generate hot air, which heats the furnace tubes of the heating furnace. It also recovers the waste heat from the hot air discharged from the heating furnace to preheat the combustion air.

2. The waste heat recovery system for large rotary kiln tail gas according to claim 1, characterized in that: The hot air furnace adopts a dual-fuel burner structure, including a natural gas inlet pipeline and a combustible exhaust gas inlet pipeline. The external natural gas is connected to the natural gas inlet pipeline through a pipeline, and the hot air discharged from the heating furnace is connected to the combustible exhaust gas inlet pipeline through a pipeline.

3. The waste heat recovery system for large rotary kiln tail gas according to claim 1, characterized in that: The gas-solid separation filter is externally wound with an auxiliary electric heating wire.

4. The waste heat recovery system for large rotary kiln tail gas according to claim 1, characterized in that: The heat exchange pipe adopts a spiral coil structure, which is coiled around the outside of the hot blast stove exhaust channel, and uses the waste heat of the exhaust gas from the heating furnace to preheat the combustion air entering the hot blast stove.

5. A large rotary kiln tail gas waste heat recovery system according to claim 1, characterized in that: The furnace tubes of the heating furnace adopt segmented heating, which is divided into a preheating section, a reaction section and a cooling section along the material travel direction. The temperature range of the preheating section is 300-500℃, the temperature range of the reaction section is 600-800℃ and the temperature range of the cooling section is 200-400℃.

6. A large rotary kiln tail gas waste heat recovery system according to claim 1, characterized in that, It also includes: a furnace tube auxiliary heating module, which includes a natural gas pipeline and a temperature compensation burner. The temperature compensation burner is evenly arranged along the furnace tube axis and is used to compensate for the temperature of the furnace tube.

7. A large rotary kiln tail gas waste heat recovery system according to claim 1, characterized in that, Also includes: A gas-solid separator insulation module, wherein the gas-solid separator insulation module has a heat tracing air duct that connects the hot air furnace to the gas-solid separator, and is used to prevent tar condensation inside the gas-solid separator.

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