Temperature regulating device for incinerator

Abstract

This invention discloses a furnace temperature control device for an incinerator, installed inside the furnace chamber. It includes multiple spaced-apart flue gas nozzles installed on the inner wall of the furnace in the high-temperature flame zone. The air inlets of these nozzles are connected to the low-temperature flue gas outlets at the tail end of a waste heat boiler via connecting pipes. This invention directly injects low-temperature flue gas from the tail end of the waste heat boiler into the high-temperature flame zone within the furnace chamber, reducing the temperature of the high-temperature flue gas and preventing the refractory lining of the furnace from being exposed to excessively high temperatures for extended periods. The spaced-apart nozzles ensure more thorough mixing of the low-temperature and high-temperature flue gas, helping to smooth out temperature peaks within the furnace, resulting in a more uniform temperature distribution, reduced localized thermal stress, and extended overall refractory material lifespan. Furthermore, it reduces the proportion of fresh combustion air, thereby lowering the overall oxygen concentration and effectively suppressing the formation of pollutants such as NOx, leading to better emission standards.

Description

Technical Field

[0001] This utility model relates to the field of incinerator technology, specifically to an incinerator temperature control device. Background Technology

[0002] In the chemical industry, direct combustion is often used to treat combustible exhaust gases. If a gas-fired boiler is used to treat the exhaust gas, the very strict "Emission Standard of Air Pollutants for Boilers" (GB 13271) will be enforced. Therefore, the exhaust gas is often treated by combining an exhaust gas incinerator with a waste heat boiler. In this case, the emission source is identified as an "exhaust gas incineration device" and is subject to the "Integrated Emission Standard of Air Pollutants" (GB 16297).

[0003] However, chemical exhaust gases often have very high calorific values, and after combustion in an incinerator, the flame and flue gas temperatures become extremely high. Under prolonged ultra-high temperatures, the refractory lining of the incinerator is prone to sintering, softening, and spalling, leading to damage to the furnace walls and a sharp increase in nitrogen oxides (NOx) within the incinerator, making it difficult to meet subsequent environmental standards. Utility Model Content

[0004] The purpose of this invention is to provide a furnace temperature control device for an incinerator to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, this utility model provides a furnace temperature control device for an incinerator, which is installed inside the furnace chamber of the incinerator. It includes multiple flue gas nozzles arranged at intervals. The flue gas nozzles are installed on the inner wall of the furnace chamber in the high-temperature area of ​​the flame. The air inlets of the multiple flue gas nozzles are connected to the low-temperature section flue gas outlet at the tail of the waste heat boiler through connecting pipes.

[0006] Furthermore, a recirculation fan is installed on the connecting pipe to pressurize the low-temperature flue gas at the tail end of the waste heat boiler.

[0007] Furthermore, the plurality of flue gas nozzles are evenly arranged circumferentially along the furnace chamber.

[0008] Furthermore, the plurality of flue gas nozzles are arranged in a U-shape within the furnace.

[0009] Furthermore, the axial direction of the flue gas nozzle is set at an angle to the flue gas flow direction inside the furnace.

[0010] Furthermore, the included angle is 45°.

[0011] The beneficial effects of this invention are as follows: This invention directly injects low-temperature flue gas from the tail end of the waste heat boiler into the high-temperature flame zone within the furnace through flue gas nozzles, reducing the temperature of the high-temperature flue gas inside the incinerator. This prevents the refractory lining material inside the furnace from being exposed to ultra-high temperatures for extended periods, avoiding sintering, softening, and spalling, and fundamentally solving the risk of furnace wall burnout. Multiple spaced nozzles ensure more thorough mixing of low-temperature and high-temperature flue gas, helping to smooth out temperature peaks within the furnace, resulting in a more uniform temperature distribution, reducing localized thermal stress, and extending the overall lifespan of the refractory material. Furthermore, it reduces the proportion of fresh combustion air, thereby lowering the overall oxygen concentration and effectively suppressing the formation of pollutants such as NOx, resulting in better emission standards. Attached Figure Description

[0012] Fig. 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0013] Fig. 2 This is a schematic diagram of the arrangement of multiple flue gas nozzles in an embodiment of the present invention.

[0014] The components include: 1. Incinerator; 2. Flue gas nozzle; 3. Connecting pipes. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only one embodiment of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] To make the objectives, technical solutions and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0017] In the following description, references to "an embodiment," "an embodiment," "an example," "example," etc., indicate that the described embodiment or example may include a particular feature, structure, characteristic, property, element, or limitation, but not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Furthermore, the repeated use of the phrase "an embodiment according to this application," while possibly referring to the same embodiment, does not necessarily refer to the same embodiment.

[0018] like Figs. 1-2As shown, this utility model discloses a furnace temperature control device for an incinerator 1, which is installed inside the furnace chamber of the incinerator 1. It includes multiple flue gas nozzles 2 arranged at intervals. The flue gas nozzles 2 are installed on the inner wall of the furnace chamber in the high-temperature zone of the flame. The air inlets of the multiple flue gas nozzles 2 are all connected to the low-temperature section flue gas outlet at the tail of the waste heat boiler through connecting pipes 3.

[0019] Chemical waste gas (typically high-calorific-value combustible waste gas) is ignited and fully combusted in the furnace of incinerator 1, producing extremely high-temperature flames and flue gas. This high-temperature flue gas enters the subsequent waste heat boiler, flowing sequentially through various heat exchange sections (such as superheaters, evaporators, and economizers), where its temperature is gradually recovered and utilized to generate steam. Finally, at the tail end (low-temperature section) of the waste heat boiler, the flue gas temperature has significantly decreased. The connecting pipe 3 of this unit leads out this portion of low-temperature, low-oxygen flue gas from this point.

[0020] The extracted low-temperature flue gas is transported through connecting pipe 3 to multiple flue gas nozzles 2 installed on the inner wall of the furnace, directly facing the high-temperature area of ​​the flame. These nozzles are spaced apart to ensure uniform coverage, while the low-temperature flue gas is injected at high speed into the core high-temperature zone of the furnace. A large amount of relatively low-temperature flue gas rapidly mixes with the high-temperature flame and flue gas, directly reducing the temperature of the mixed gas physically. Furthermore, because the introduced recirculated flue gas occupies the combustion space, it reduces the proportion of fresh combustion air, thereby lowering the overall oxygen concentration and effectively suppressing the formation of pollutants such as NOx, resulting in better emission standards.

[0021] This invention directly injects low-temperature flue gas from the tail end of the waste heat boiler into the high-temperature flame zone within the furnace via flue gas nozzles 2. This lowers the temperature of the high-temperature flue gas inside the incinerator 1, preventing the refractory lining material from being exposed to ultra-high temperatures for extended periods, thus avoiding sintering, softening, and spalling, and fundamentally eliminating the risk of furnace wall burnout. Multiple spaced nozzles ensure more thorough mixing of the low-temperature and high-temperature flue gas, helping to smooth out temperature peaks within the furnace, resulting in a more uniform temperature distribution, reduced localized thermal stress, and extended overall refractory material lifespan. Furthermore, it reduces the proportion of fresh combustion air, thereby lowering the overall oxygen concentration and effectively suppressing the formation of pollutants such as NOx, leading to better emission standards.

[0022] In one embodiment, a recirculation fan is installed on the connecting pipe 3 to pressurize the low-temperature flue gas at the tail end of the waste heat boiler.

[0023] The waste heat boiler's tail flue is under negative pressure, and the pressure is low. This pressure difference alone is insufficient to reliably deliver a sufficient quantity of low-temperature flue gas to the core flame zone of the furnace, which is under positive or slightly negative pressure, especially when higher flow velocities are required at the nozzles for good penetration and mixing. The recirculation fan provides the necessary, adjustable booster power, ensuring that a sufficient quantity of low-temperature flue gas can be extracted and delivered on demand, regardless of fluctuations in the main system's operating conditions.

[0024] Simultaneously, by adjusting the speed of the recirculation fan (e.g., using frequency converter control), the flow rate and pressure of the recirculated flue gas can be precisely and linearly adjusted. This transforms furnace temperature control from coarsely adjustable to finely controllable, enabling more sensitive responses to changes in the calorific value or load of the incinerator 1 inlet exhaust gas, achieving constant temperature control in the high-temperature zone of the furnace. In other words, by adjusting the recirculated flue gas volume, changes in the calorific value of the exhaust gas can be flexibly addressed, making the system operation more stable and controllable.

[0025] In one embodiment, multiple flue gas nozzles 2 are uniformly arranged circumferentially along the furnace. During the combustion of high-calorific-value exhaust gases, the flame morphology may be unstable or exhibit off-center burning, leading to uneven circumferential temperature in the furnace. The uniformly arranged nozzles form a continuous low-temperature flue gas barrier surrounding the flame. Regardless of the direction in which the high-temperature zone appears, it receives direct and equal-intensity cooling intervention from the nearest nozzle, thereby forcibly smoothing the circumferential temperature gradient and effectively eliminating the risk of local overheating. At the same time, it uniformly reduces the oxygen concentration around the flame core, making it difficult for oxygen to diffuse towards the flame center, thus creating a uniform environment in three-dimensional space that suppresses NOx formation.

[0026] In one embodiment, multiple flue gas nozzles 2 are arranged in a U-shape within the furnace. That is, the multiple flue gas nozzles 2 are concentrated on the horizontal cross-section where the high-temperature flame region is located within the furnace, and are arranged circumferentially along the furnace wall of this cross-section. From a side view, the nozzle group forms a "U"-shaped injection band located in the lower middle part of the furnace. The high-speed, low-temperature flue gas ejected from the U-shaped band forms a strong lateral shear and vertical momentum exchange with the rising high-temperature main airflow at the bottom of the furnace, effectively disrupting the natural upward flow of the flame and creating significant turbulence in the high-temperature zone. This allows the cooling and oxygen reduction effects to be completed instantaneously, maximizing the utilization of the heat capacity and chemical inhibition capabilities of the temperature-regulating flue gas.

[0027] In one embodiment, the axis of the flue gas nozzle 2 is set at an angle to the flue gas flow direction within the furnace. The strong shearing and swirling flow generated by this angle converts the momentum energy of the injected low-temperature flue gas into turbulent kinetic energy most effectively, which is the physical basis for achieving rapid and uniform mixing. This maximizes the cooling and dilution effect of the temperature-regulating flue gas per unit volume. Furthermore, it avoids the potential for excessive localized cooling or erosion wear caused by prolonged direct impact of a low-temperature, high-speed jet onto the opposite furnace wall or nozzle.

[0028] In one embodiment, the included angle is 45°.

[0029] In this embodiment of the invention, multiple flue gas nozzles 2 with a 45° angle are opened in the furnace area of ​​the high-temperature flame zone of the incinerator 1. They are arranged in a U-shape around the circumference. The flue gas from the low-temperature section of the waste heat boiler is pressurized by the flue gas recirculation fan and introduced into the multiple flue gas nozzles 2 in the incinerator 1 to regulate the furnace temperature of the incinerator 1.

[0030] The high-temperature flue gas from incinerator 1 can be reduced from 1400℃ to below 950℃, protecting the incinerator body. This solves the problem of easily burned-out furnace walls, significantly extending the service life of the furnace walls in incinerator 1. The introduced recirculated flue gas occupies the combustion space, reducing the proportion of fresh combustion air and thus lowering the overall oxygen concentration, effectively suppressing the formation of pollutants such as NOx and resulting in better emission standards. Simultaneously, by adjusting the recirculated flue gas volume, changes in the calorific value of the exhaust gas can be flexibly addressed, making the system operation more stable and controllable.

[0031] The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A furnace temperature control device for an incinerator, installed inside the furnace chamber of an incinerator, characterized in that: It includes multiple flue gas nozzles spaced apart, which are installed on the inner wall of the furnace in the high-temperature zone of the flame. The air inlets of the multiple flue gas nozzles are connected to the low-temperature section flue gas outlet at the tail of the waste heat boiler through connecting pipes.

2. The incinerator temperature control device according to claim 1, characterized in that: A recirculation fan is installed on the connecting pipe to pressurize the low-temperature flue gas at the tail end of the waste heat boiler.

3. The incinerator temperature control device according to claim 1, characterized in that: The plurality of flue gas nozzles are evenly arranged around the circumference of the furnace.

4. The incinerator temperature control device according to claim 3, characterized in that: The multiple flue gas nozzles are arranged in a U-shape inside the furnace.

5. The incinerator temperature control device according to claim 1, characterized in that: The axis of the flue gas nozzle is set at an angle to the direction of flue gas flow in the furnace.

6. The incinerator temperature control device according to claim 5, characterized in that: The included angle is 45°.

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