Low-energy-consumption and high-safety incineration method

Abstract

The invention discloses a low-energy-consumption and high-safety incineration method which sequentially comprises the steps of waste gas pretreatment, high-temperature incineration, two-stage waste heat recovery and up-to-standard emission, and emergency safeguard measures are additionally arranged. The core system comprises a waste gas mixer, an incinerator, a combustor, a boiler, a rotary heat exchanger, a chimney and the like. In the pretreatment stage, the concentration of organic matters in waste gas is controlled within a safety range of less than or equal to 25% LEL through a flow verification function of a waste gas mixer; during high-temperature incineration, a combustor with an adjusting channel is used for preventing backfire, and oxygen supplementing air is preheated to 120-230 DEG C through a rotary heat exchanger; the two-stage waste heat recovery is realized through steam generated by a boiler and air preheating by a rotary heat exchanger; the method has efficient heat recovery capability and multiple safety protection, can ensure thorough degradation of organic matters, remarkably reduces operation energy consumption, and improves system safety and economical efficiency.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology, specifically to a low-energy-consumption and high-safety incineration method. Background Technology

[0002] Existing waste gas incineration technologies face the following two core technical challenges in practical applications:

[0003] Existing technologies often employ single waste heat recovery devices (such as boilers or heat exchangers alone), which cannot fully recover the heat from the high-temperature flue gas generated during incineration. A large amount of heat is wasted with the flue gas emissions, resulting in the system needing to consume additional energy to maintain operation, significantly increasing operating costs.

[0004] The exhaust gas has a complex composition and fluctuates greatly in concentration. Existing technologies make it difficult to accurately control the safe concentration of exhaust gas. At the same time, there is a lack of effective backfire prevention design, which can easily lead to flame backflow (backfire) into the exhaust gas pipeline, posing a safety hazard of explosion or pipeline burnout. Summary of the Invention

[0005] To address the aforementioned technical problems, this application solves the issues of low heat recovery efficiency and high energy consumption and cost in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is: a low-energy-consumption and high-safety incineration method, comprising the following steps:

[0007] Step (1) Waste gas pretreatment: The low oxygen content waste gas is sent into the waste gas mixer by the waste gas exhaust fan. After the concentration of organic matter in the waste gas is controlled within a safe range by the flow verification function of the waste gas mixer, the pretreated waste gas is sent to the furnace of the incinerator.

[0008] Step (2), High-temperature incineration: Start the burner connected to the incinerator, and at the same time send air into the rotary heat exchanger through the oxidation blower. After the air is heated in the rotary heat exchanger, it is delivered to the furnace of the incinerator as supplementary oxygen air to supplement the oxygen required for combustion. Control the temperature in the incinerator so that the pretreated waste gas stays in the incinerator for a preset time to achieve the oxidation and degradation of organic matter.

[0009] Step (3), two-stage waste heat recovery: the high-temperature flue gas generated by incineration first enters the boiler evaporator, and the first-stage waste heat recovery is achieved through heat exchange. The cooled flue gas then enters the rotary heat exchanger to heat up the air in the step, thus achieving the second-stage waste heat recovery.

[0010] Step (4) Emission in compliance with standards: The flue gas after secondary waste heat recovery is discharged through the chimney.

[0011] To better realize the present invention, further, in step (1), the safety range is ≤25%LEL of organic matter concentration in the exhaust gas.

[0012] To better realize the present invention, further, in step (2), the temperature inside the incinerator is ≥800℃ and the preset time is ≥1s.

[0013] To better realize the present invention, further, in step (2), the nozzle of the burner is provided with an adjustment channel. The airflow is controlled by adjusting the channel to ensure high flow rate and low temperature operation of the exhaust gas, so as to achieve no backfire, timely pressure relief, and prevent the flame from being transmitted to the exhaust gas pipeline.

[0014] To better realize the present invention, further, in step (2), the rotary heat exchanger is made of heat storage material, and uses the heat of flue gas discharged from the boiler evaporator to heat the air, so that the temperature of the oxygen-supplemented air reaches 120℃~230℃.

[0015] To better realize the present invention, further, in step (3), the boiler also includes a steam drum, a deaerator, a sewage pump and a feed water pump; during the primary waste heat recovery process, the flue gas and water heat exchange is realized inside the evaporator, the wastewater generated by the steam drum is discharged through the sewage pump, and the soft water treated by the deaerator is transported to the steam drum for water replenishment through the feed water pump; the steam generated by the boiler through the primary waste heat recovery is used by other equipment in the plant area.

[0016] The technical solution provided by this invention has the following advantages compared with the prior art:

[0017] 1. In this invention, a waste gas mixer with flow verification function is used in the waste gas pretreatment stage. A flow sensor monitors the waste gas flow rate in real time, and an electric regulating valve is used to strictly control the concentration of organic matter in the waste gas within a safe range of ≤25% LEL. Precise control of the waste gas concentration before it enters the incinerator ensures that the waste gas is in a non-flammable and non-explosive state. This avoids the risk of explosion in the incinerator or pipelines due to excessively high organic matter concentration in the waste gas (exceeding the lower explosive limit).

[0018] Establishing a safety barrier at the initial stage of the incineration process (pretreatment) lays a safe foundation for the stable operation of subsequent high-temperature incineration and reduces the probability of safety accidents during the pretreatment stage.

[0019] 2. In this invention, the burner nozzle is equipped with multiple sets of adjustable vane-type regulating channels. The vane opening is controlled by an electric actuator to regulate the airflow state, ensuring high flow velocity and low temperature operation of the exhaust gas within the incinerator. This directional control of the airflow direction and speed during combustion blocks the path of flame transmission to the exhaust gas pipeline and enables timely pressure relief. It prevents flame backflow (flashback) into the exhaust gas pipeline, avoiding the flame igniting residual exhaust gas within the pipeline. This eliminates the critical "flashback" safety hazard during the high-temperature combustion stage, protecting the exhaust gas pipeline and front-end pretreatment equipment, extending equipment lifespan, and reducing the incidence of safety accidents during combustion.

[0020] 3. This invention employs a combined model of "primary waste heat recovery from a boiler evaporator + secondary waste heat recovery from a rotary heat exchanger," wherein the rotary heat exchanger uses ceramic regenerator material. Primary recovery generates 0.8MPa saturated steam through heat exchange between the boiler evaporator and high-temperature flue gas. Secondary recovery absorbs waste heat from the flue gas through the rotary heat exchanger, preheating the supplementary oxygen air to 120℃~230℃. This efficiently recovers the heat from the high-temperature flue gas generated during incineration, achieving "tiered heat utilization"—primary recovery produces reusable steam, and secondary recovery increases the heat of the supplementary oxygen air, reducing system operating energy consumption. It reduces heat waste caused by direct emissions of high-temperature flue gas and simultaneously lowers the operating energy consumption of the incinerator; the produced steam can be supplied to other production equipment in the plant, achieving secondary energy utilization. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the incineration method of the present invention;

[0023] Figure 2 This is a schematic diagram of the layout for the waste gas incineration of the present invention.

[0024] Explanation of reference numerals in the attached drawings: 1-Waste gas mixer; 2-Waste gas induced draft fan; 3-Burner; 4-Incinerator; 5-Evaporator; 6-Rotary heat exchanger; 7-Oxidation fan; 8-Chimney; 9-Steam drum; 10-Sewage pump; 11-Water supply pump; 12-Deaerator. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0030] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Example 1

[0032] like Figure 1 and Figure 2 As shown, a low-energy, high-safety incineration method includes the following steps:

[0033] Step (1) Waste gas pretreatment: The low oxygen content waste gas is sent into the waste gas mixer 1 by the waste gas induced draft fan 2. The flow verification function of the waste gas mixer 1 is used to monitor the waste gas flow in real time by the flow sensor and adjust the intake volume with the electric regulating valve. After the concentration of organic matter in the waste gas is controlled within a safe range, the pretreated waste gas is sent to the furnace of the incinerator 4.

[0034] Step (2), High-temperature incineration: Start the burner 3 connected to the incinerator 4, and at the same time send air into the rotary heat exchanger 6 through the oxidation blower 7. After the air is heated in the rotary heat exchanger 6, it is delivered to the furnace of the incinerator 4 as supplementary oxygen air to supplement the oxygen required for incineration. Control the temperature in the incinerator 4 so that the pretreated waste gas stays in the incinerator 4 for a preset time to achieve the oxidation and degradation of organic matter.

[0035] Step (3), two-stage waste heat recovery: the high-temperature flue gas generated by incineration first enters the boiler evaporator 5, and realizes the first-stage waste heat recovery through heat exchange. The cooled flue gas then enters the rotary heat exchanger 6 to heat up the air in step (2) and realize the second-stage waste heat recovery.

[0036] Step (4) Emission in compliance with standards: The flue gas after secondary waste heat recovery is discharged through chimney 8.

[0037] like Figure 1 and Figure 2 As shown, in this embodiment, in step (1), the safe range is the concentration of organic matter in the exhaust gas ≤25%LEL.

[0038] like Figure 1 and Figure 2 As shown, in this embodiment, in step (2), the temperature inside the incinerator 4 is ≥800℃ and the preset time is ≥1s.

[0039] like Figure 1 and Figure 2 As shown, in this embodiment, in step (2), the nozzle of the burner 3 is provided with an adjustment channel. The adjustment channel is a multi-set adjustable blade structure. The blade opening is controlled by an electric actuator, and the airflow is controlled by the adjustment channel to ensure high flow rate and low temperature operation of the exhaust gas, so as to achieve no backfire, timely pressure relief, and prevent the flame from being transmitted to the exhaust gas pipeline.

[0040] like Figure 1 and Figure 2 As shown, in this embodiment, in step (2), the rotary heat exchanger 6 is made of ceramic heat storage material. It uses the heat of flue gas discharged from the boiler evaporator to heat the air, so that the temperature of the oxygen-supplemented air reaches 120℃~230℃. The rotation speed of the heat exchanger is adjusted by the feedback signal of the temperature sensor to maintain the stability of the temperature rise.

[0041] like Figure 1 and Figure 2As shown, in this embodiment, in step (3), the boiler also includes a steam drum 9, a deaerator 12, a sewage pump 10, and a feedwater pump 11; during the primary waste heat recovery process, the evaporator 5 exchanges heat with the steam drum 9, and saturated steam at 0.8 MPa is generated in the steam drum 9. The wastewater generated by the steam drum 9 is discharged through the sewage pump 10, and the soft water treated by the deaerator 12 is transported to the steam drum 9 for water replenishment through the feedwater pump 11; the deaerator 12 first heats the soft water to 104°C to complete the deoxygenation treatment, and the feedwater pump 11 pressurizes the deoxygenated soft water to 1.2 MPa and then transports it to the steam drum 9. The steam generated by the boiler through the primary waste heat recovery is used by other equipment in the plant area.

[0042] This invention employs a closed-loop process of "waste gas pretreatment - high-temperature oxidation - two-stage waste heat recovery - safe emission," combined with optimized equipment structure and precise parameter control. This ensures efficient waste gas purification while reducing energy consumption, and multiple safety designs prevent risks such as backfire and overheating during incineration. Specific analysis follows:

[0043] Before starting, a joint inspection of the equipment must be completed to ensure that there are no leaks in the connecting pipes between the exhaust gas induced draft fan 2, oxidation fan 7, incinerator 4, boiler, and rotary heat exchanger 6; start the deaerator 12 to preheat the soft water, raising the temperature of the soft water to 104℃ to remove oxygen from the water, and at the same time prepare natural gas as ignition fuel for burner 3, and ensure that the boiler water supply system and sewage discharge system are in standby status.

[0044] Start the exhaust gas induced draft fan 2 to introduce the low-oxygen content exhaust gas to be treated into the exhaust gas mixer 1. The mixer has a built-in flow sensor and an electric regulating valve. The flow sensor collects the exhaust gas flow data in real time and feeds it back to the control system to adjust the opening of the electric regulating valve. The concentration of organic matter in the exhaust gas is strictly controlled within a safe range of less than 25% LEL to avoid the risk of combustion and explosion due to excessive concentration. The pretreated exhaust gas is sent to the furnace of the incinerator 4 through a dedicated pipeline. The exhaust gas flow rate in the pipeline is controlled at 13~16m / s to ensure stable and unfluctuating airflow.

[0045] The burner 3 is ignited. The multiple adjustable blades of the burner 3 nozzle are adjusted by an electric actuator to control the airflow state during exhaust gas combustion, achieving high flow rate and low temperature operation, and preventing the flame from being transmitted to the exhaust gas pipeline. At the same time, the oxidation fan 7 is started to send ambient air into the rotary heat exchanger 6 for preheating. The ceramic heat storage body in the heat exchanger absorbs the heat of the subsequent flue gas, raising the air temperature to 120℃~230℃, and then sends it into the incinerator 4 as supplementary oxygen air to supplement the oxygen required for combustion. The temperature of the furnace is monitored in real time by the temperature sensor built into the incinerator 4, maintaining the temperature ≥800℃, and ensuring that the residence time of the exhaust gas in the furnace is ≥1s, so that the organic matter is fully oxidized and degraded into water and carbon dioxide.

[0046] Primary waste heat recovery: The high-temperature flue gas of about 850°C generated by incineration enters the boiler evaporator 5, and the heat is transferred to the soft water in the steam drum 9 through heat exchange, so that 0.8MPa saturated steam is generated in the steam drum 9. The steam is supplied to other production equipment in the plant through the pipeline, realizing the recovery and utilization of heat energy; after this process, the flue gas temperature drops to about 250°C.

[0047] Secondary waste heat recovery: The cooled flue gas enters the rotary heat exchanger 6 and exchanges heat with the ceramic heat storage body. The heat storage body absorbs the heat of the flue gas and uses it to preheat the cold air sent in by the oxidation fan 7, thus completing the heat recycling. After heat exchange, the flue gas temperature is further reduced to about 120°C, effectively reducing the system energy consumption.

[0048] When shutting down, first turn off the exhaust gas induced draft fan 2, then stop the burner 3, and continue running the oxidation fan 7 to completely purge the residual exhaust gas in the furnace. After the temperature of the incinerator 4 drops below 200℃, turn off the oxidation fan 7, boiler-related equipment and rotary heat exchanger 6 in sequence to complete the shutdown of the entire incineration system.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A low-energy-consumption and high-safety incineration method, characterized in that: Includes the following steps: Step (1), waste gas pretreatment: the low oxygen content waste gas is sent into the waste gas mixer (1) by the waste gas induced draft fan (2). After the concentration of organic matter in the waste gas is controlled within a safe range by the flow verification function of the waste gas mixer (1), the pretreated waste gas is sent to the furnace of the incinerator (4). Step (2), high-temperature incineration: Start the burner (3) connected to the incinerator (4), and at the same time send air into the rotary heat exchanger (6) through the oxidation blower (7), so that the air is heated in the rotary heat exchanger (6) and then delivered to the furnace of the incinerator (4) as supplementary oxygen air to supplement the oxygen required for incineration; control the temperature in the incinerator (4) so ​​that the pretreated waste gas stays in the incinerator (4) for a preset time to achieve the oxidation and degradation of organic matter; Step (3), two-stage waste heat recovery: the high-temperature flue gas generated by incineration first enters the boiler evaporator (5) and realizes the first-stage waste heat recovery through heat exchange. The cooled flue gas then enters the rotary heat exchanger (6) to heat up the air in step (2) and realize the second-stage waste heat recovery. Step (4) Emission in compliance with standards: The flue gas after secondary waste heat recovery is discharged through the chimney (8).

2. The low-energy-consumption and high-safety incineration method according to claim 1, characterized in that: In step (1), the safe range is the concentration of organic matter in the exhaust gas ≤25%LEL.

3. The low-energy-consumption and high-safety incineration method according to claim 1, characterized in that: In step (2), the temperature inside the incinerator (4) is ≥800℃ and the preset time is ≥1s.

4. The low-energy-consumption and high-safety incineration method according to claim 1, characterized in that: In step (2), the nozzle of the burner (3) is equipped with an adjustment channel. The airflow is controlled by adjusting the channel to ensure high flow rate and low temperature operation of the exhaust gas, so as to achieve no backfire, timely pressure relief, and prevent the flame from being transmitted to the exhaust gas pipeline.

5. The low-energy-consumption and high-safety incineration method according to claim 1, characterized in that: In step (2), the rotary heat exchanger (6) is made of heat storage material and uses the heat of flue gas discharged from the boiler evaporator to heat the air, so that the temperature of the oxygen-supplemented air reaches 120℃~230℃.

6. The low-energy-consumption and high-safety incineration method according to claim 1, characterized in that: In step (3), the boiler also includes a steam drum (9), a deaerator (12), a sewage pump (10), and a feedwater pump (11); during the primary waste heat recovery process, the flue gas in the evaporator (5) exchanges heat with water, the wastewater generated by the steam drum (9) is discharged through the sewage pump (10), and the soft water treated by the deaerator (12) is transported to the steam drum (9) for water replenishment through the feedwater pump (11); the steam generated by the boiler through the primary waste heat recovery is used by other equipment in the plant area.

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