Integrated process for carbonization incineration of dead animals - waste heat recovery

Abstract

The application discloses a carcass carbonization incineration-waste heat recovery integrated process and relates to the field of organic solid waste treatment. The application comprises the following steps: anaerobic pyrolysis of carcass material in a pyrolysis carbonization chamber to generate pyrolysis gas and solid carbonized substances; the pyrolysis gas is introduced into a high-temperature combustion chamber to be combusted to generate high-temperature flue gas; the high-temperature flue gas is introduced into an outer heating jacket of the pyrolysis carbonization chamber to provide pyrolysis heat; after heat exchange, the flue gas enters a waste heat recovery unit to preheat combustion-supporting air and dry the material fed into the chamber; and the low-temperature flue gas is purified and discharged. The pyrolysis carbonization chamber and the high-temperature combustion chamber are coaxially nested, and the wall surface of the pyrolysis carbonization chamber is provided with a flue gas channel connected with the high-temperature combustion chamber. Through pyrolysis-incineration coupling and gradient waste heat recovery, the application realizes harmless treatment of carcass material and energy self-sustaining operation.

Description

Technical Field

[0001] This invention relates to the field of organic solid waste treatment, and more specifically, to an integrated process for carbonization and incineration of dead animals and waste heat recovery. Background Technology

[0002] Animal carcasses and their slaughter waste are classified as special organic solid waste, carrying a large number of pathogenic microorganisms. Improper disposal can seriously endanger public health and the ecological environment. Currently, the main methods for the harmless treatment of dead animals include incineration, landfill, rendering, and aerobic fermentation. Incineration involves oxidizing the dead animals at high temperatures to completely eliminate pathogens, but it suffers from high operating costs, high auxiliary fuel consumption, heavy burden on flue gas treatment, and low waste heat utilization. Landfilling can easily lead to groundwater pollution and the spread of pathogenic microorganisms.

[0003] In the prior art, Chinese patent CN112139223A discloses a harmless treatment system and process for animal carcasses, employing a high-temperature and high-pressure chemical treatment method. This involves sterilizing and drying the carcasses by introducing saturated steam into the chemical treatment tank, and the treated material can be used as organic fertilizer or animal feed. This process relies on external steam heating, resulting in high energy consumption, and the biosafety of the products after wet heat treatment is controversial. Chinese patent CN106824972A discloses a comprehensive pollution control system and method for large-scale pig farms, treating manure and carcasses of diseased pigs through solid and liquid high-temperature aerobic fermentation, and incorporating an odor and flue gas treatment system. This process has a long processing cycle, requires a large area, and the fermentation process requires external boiler heating, thus its energy utilization efficiency needs improvement. Therefore, an integrated process of carbonization and incineration of dead animals and waste heat recovery is proposed to address the above problems. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide an integrated process for carbonization and incineration of dead animals and waste heat recovery, which aims to solve the problems of large auxiliary fuel consumption, low waste heat utilization rate and heavy flue gas treatment burden in the existing incineration method for treating dead animals, as well as the problems of high energy consumption, long processing cycle and low product added value in existing processes such as rendering and fermentation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An integrated process for carbonization and incineration of diseased and dead animals, including the following steps: S1: Place the dead animal material in the pyrolysis and carbonization chamber and carry out the pyrolysis reaction in the oxygen-deficient environment to generate pyrolysis gas and solid carbon, so that the organic matter in the dead animal material decomposes into combustible gas and solid carbon under anaerobic conditions. S2: The pyrolysis gas is introduced into the high-temperature combustion chamber, mixed with preheated combustion air, and then burned to generate high-temperature flue gas. The combustible components in the pyrolysis gas are converted into heat energy through combustion. S3: The high-temperature flue gas is introduced into the external heating jacket of the pyrolysis carbonization chamber to provide heat to the pyrolysis carbonization chamber through indirect heat exchange, thereby realizing the in-situ reuse of the heat required for the pyrolysis reaction; S4: The flue gas after heat exchange in the pyrolysis and carbonization chamber enters the waste heat recovery unit, which preheats the combustion air and dries the materials entering the furnace in sequence, thereby reducing system energy consumption through cascade utilization. S5: The low-temperature flue gas after heat exchange in the waste heat recovery unit enters the flue gas purification unit for treatment before being discharged to ensure that the exhaust gas meets the standards. The pyrolysis carbonization chamber and the high-temperature burnout chamber are arranged in a coaxial nested structure, with the pyrolysis carbonization chamber located in the inner layer and the high-temperature burnout chamber located in the outer jacket. A flue gas channel is provided on the wall of the pyrolysis carbonization chamber to connect with the high-temperature burnout chamber. The flue gas channel introduces the pyrolysis gas into the high-temperature burnout chamber and retains the solid carbonized material in the pyrolysis carbonization chamber, thereby realizing the integrated coupling of pyrolysis and combustion.

[0006] Furthermore, the wall of the pyrolysis carbonization chamber described in S1 consists of, from the inside out, a material contact layer, a filter and flow guiding layer, and a structural support layer.

[0007] The contact material layer is made of a porous corrugated plate, which uses its uneven surface to generate a mechanical scraping effect during material movement to prevent tar and particulate matter from adhering.

[0008] The filter guide layer is composed of at least two layers of metal wire mesh with different mesh counts. The mesh count of the metal wire mesh near the inner layer is smaller than that near the outer layer. The gradient interception achieves graded filtration and coagulation reflux of tar droplets and particulate matter.

[0009] The pyrolysis gas passes sequentially through the contact material layer, the filter and guide layer, and the structural support layer before entering the high-temperature combustion chamber, where it undergoes in-situ purification before leaving the pyrolysis and carbonization chamber.

[0010] Furthermore, in S2, the pyrolysis gas enters the bottom of the high-temperature combustion chamber and forms a rotating airflow. The rotating airflow is guided by guide vanes, the angle of which is adjustable, and the swirling effect enhances mixing and stable combustion.

[0011] The pyrolysis gas is mixed and burned sequentially with primary air and secondary air. The primary air accounts for 20% to 30% of the total combustion air and is used to form a fuel-rich zone to suppress the generation of thermal nitrogen oxides. The secondary air accounts for 70% to 80% of the total combustion air and is used to achieve complete combustion.

[0012] Furthermore, S2 also includes a flue gas recirculation step: a portion of the high-temperature flue gas in the upper part of the high-temperature combustion chamber is led back to the bottom of the high-temperature combustion chamber through a recirculation channel, mixed with the pyrolysis gas that enters, and then burned. The amount of recirculated flue gas accounts for 20% to 35% of the total amount of flue gas in the high-temperature combustion chamber. The temperature of the combustion zone is reduced and the temperature field is uniform by diluting the high-temperature flue gas.

[0013] Furthermore, prior to S1, a material testing step is included: online component analysis of the dead animal material to obtain a moisture content value. The ratio of fat to protein mass was measured. This provides a basis for setting process parameters. The pyrolysis temperature setpoint for the pyrolysis carbonization chamber mentioned in S1... and material residence time according to the above and stated Adjustments are made to match the pyrolysis conditions with the material properties.

[0014] Furthermore, S2 also includes a gas monitoring step: Regarding the carbon monoxide content in the pyrolysis gas Hydrogen content and methane content Online monitoring is conducted to assess the depth of the pyrolysis reaction and the calorific value of the pyrolysis gas.

[0015] when A concentration below 40% indicates incomplete pyrolysis; therefore, the pyrolysis temperature should be adjusted accordingly. Increase by 20 Or reduce the feeding speed Reduced by 10%; when A value above 55% indicates that the calorific value of the pyrolysis gas is too high, which will lower the pyrolysis temperature. Reduce by 20 Or reduce the feeding speed Increase by 10%, and maintain stable pyrolysis gas quality through feedback adjustment.

[0016] Furthermore, the waste heat recovery unit in S4 includes a first-stage heat exchanger and a second-stage heat exchanger. The first-stage heat exchanger preheats the combustion air to 80°C. Up to 150 This improves combustion efficiency and reduces energy loss; The second-stage heat exchanger dries the material fed into the furnace to a moisture content of less than 15%, reducing energy consumption during the pyrolysis process.

[0017] Furthermore, the combustion temperature of the high-temperature burnout chamber described in S2 is controlled at 900°C. Up to 1200 The flue gas residence time is greater than 2 seconds to ensure complete decomposition of organic matter and inhibit dioxin formation.

[0018] The high-temperature combustion chamber is equipped with a bottom temperature monitoring point, a middle temperature monitoring point, and an upper temperature monitoring point, which are used to monitor the temperature of the combustion chamber. , and This provides temperature feedback for combustion control.

[0019] Furthermore, the process of this invention also includes a collaborative control step, the specific adjustment rules of which are as follows: Set the temperature monitoring value in the middle of the pyrolysis carbonization chamber. With pyrolysis temperature setpoint The deviation is ,when Adjustments should be made as needed.

[0020] like This indicates that the pyrolysis temperature is too low, and the feed rate should be reduced. reduce At the same time, the ratio of primary wind to secondary wind is adjusted. Increase by 1 percentage point The maximum adjustment range shall not exceed 20% and 10 percentage points; like This indicates that the pyrolysis temperature is too high, and the feed rate should be reduced. improve At the same time Lower by 1 percentage point The maximum adjustment range shall not exceed 20% and 10 percentage points.

[0021] When the temperature monitoring value in the middle of the high-temperature combustion chamber Above 1100 When the combustion is too intense, the proportion of high-temperature flue gas recirculated should be increased. Increase by 5 percentage points to dilute and cool; when Below 950 When this time, it indicates insufficient combustion. Reduce by 5 percentage points to enhance combustion; when Restored to 1000 Up to 1080 After the interval, it will be increased at a rate of 1 percentage point per minute. Gradually revert to the initial setting to avoid over-adjustment.

[0022] Furthermore, the heat generated by the combustion of the pyrolysis gas in S2 sustains the heat required for the pyrolysis reaction in S1 and the drying of the material entering the furnace in S4, thereby achieving self-sustaining operation of the system.

[0023] The technical effects and advantages of this invention are as follows: This invention couples the pyrolysis reaction and pyrolysis gas combustion into a single integrated unit through a coaxial nested structure design of a pyrolysis carbonization chamber and a high-temperature combustion chamber. A flue gas channel on the wall of the pyrolysis carbonization chamber directly guides the pyrolysis gas into the outer high-temperature combustion chamber, while simultaneously retaining solid carbonized material in the inner layer, achieving in-situ extraction of the pyrolysis gas and separation of solid products. This structure simplifies the process flow, reduces the equipment footprint, and avoids heat loss and tar condensation problems during pyrolysis gas transmission.

[0024] This invention employs a gradient pore size structure on the wall of the pyrolysis carbonization chamber, consisting of a material contact layer, a filter guide layer, and a structural support layer. The porous corrugated plates of the material contact layer generate a mechanical scraping effect during material movement, helping to prevent tar and particulate matter adhesion. The multiple layers of metal wire mesh with different mesh sizes in the filter guide layer achieve graded filtration and condensation recirculation of tar droplets and particulate matter through gradient interception. This design allows the pyrolysis gas to undergo in-situ purification before leaving the pyrolysis carbonization chamber, helping to reduce the load on subsequent flue gas purification units.

[0025] This invention employs a combustion method combining staged air distribution and internal flue gas recirculation in the high-temperature burnout chamber. After the pyrolysis gas passes through guide vanes to form a rotating airflow, it is sequentially mixed with primary and secondary air for combustion. The primary air, comprising 20% ​​to 30% of the total combustion air, is used to create a fuel-rich zone and suppress nitrogen oxide formation, while the secondary air is used to achieve complete combustion. Simultaneously, a portion of the high-temperature flue gas from the upper part of the high-temperature burnout chamber is drawn back to the bottom to mix with the pyrolysis gas, which helps to dilute the temperature in the combustion zone, homogenize the temperature field, and improve combustion stability.

[0026] This invention employs a tiered waste heat recovery method to fully utilize the system's heat. High-temperature flue gas first provides the heat required for pyrolysis in the pyrolysis and carbonization chamber. The medium-temperature flue gas, after heat exchange, is then used sequentially to preheat the combustion air and dry the materials fed into the furnace. This step-by-step utilization based on temperature and grade helps improve the system's thermal efficiency, ensuring that the heat generated by the combustion of the pyrolysis gas is sufficient to sustain the pyrolysis reaction and material drying, thus achieving energy self-sufficiency for the system.

[0027] This invention introduces a synergistic control strategy combining material characteristic detection and pyrolysis gas composition monitoring. The pyrolysis temperature setpoint is adjusted based on online detection of material moisture content and fat-to-protein ratio to match the pyrolysis conditions with the material characteristics. Feed rate and pyrolysis temperature are adjusted based on feedback from the carbon monoxide, hydrogen, and methane content in the pyrolysis gas to maintain stable pyrolysis gas quality. This control strategy helps improve the process's adaptability to different types of dead animal materials, ensuring the stability and reliability of the system operation. Attached Figure Description

[0028] Figure 1 This is a linear flow diagram of the overall process of the present invention; Figure 2This is a diagram of the coaxial nested structure of the core device of the present invention; Figure 3 This is the collaborative control feedback adjustment branch diagram of the present invention; Figure 4 This is the branch diagram of the collaborative control feedback adjustment of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] As attached Figures 1 to 4 The integrated carbonization and incineration-waste heat recovery process for dead animals, as shown, is implemented as follows: The process is achieved through an integrated system, which mainly includes a pyrolysis carbonization chamber, a high-temperature combustion chamber, a waste heat recovery unit, a flue gas purification unit, and supporting detection and control devices. The units are connected by pipes and valves to achieve continuous or semi-continuous material processing.

[0031] Example 1: Basic Process for Disposing of Dead Pig Carcasses This embodiment uses the carcasses of diseased and dead pigs as the processing object, and details the specific implementation steps of the process.

[0032] S1: Material Pretreatment and Testing The carcasses of diseased and dead pigs are crushed into lumps with a particle size of less than 80mm by a crusher, and then fed into the raw material buffer silo via a closed screw conveyor. A near-infrared online composition analyzer is installed on the feed pipe to monitor the moisture content of the material in real time. The ratio of fat to protein mass In this embodiment, the detected... , .according to and The system is preset to the initial temperature of the pyrolysis reaction. 580 The initial pyrolysis time was set to 70 minutes.

[0033] and and The correspondence is established based on thermogravimetric analysis experiments: when For every 10 percentage point increase, Increase accordingly by 15 To compensate for the heat absorbed by water evaporation; when For every increase of 0.5, Reduced by 10 accordingly This embodiment utilizes the pyrolysis of fat to release heat. , Preset That is, it is calculated based on this relationship.

[0034] S2: Pyrolysis reaction Dead animal material is fed through the feeding device at a speed The material is fed into the pyrolysis carbonization chamber. The pyrolysis carbonization chamber is a horizontal cylindrical structure, and the interior is kept in an oxygen-deficient environment by filling the chamber with nitrogen to keep the oxygen volume concentration below 2%. The material is indirectly heated in the pyrolysis carbonization chamber, undergoing a pyrolysis reaction to generate pyrolysis gas and solid carbonized products.

[0035] The walls of the pyrolysis carbonization chamber, from the inside out, consist of a material contact layer, a filter and flow guiding layer, and a structural support layer. The material contact layer uses a 3mm thick porous corrugated plate with a corrugation height of 10mm, a corrugation spacing of 20mm, and an opening diameter of 2mm, resulting in an opening rate of 15%. The uneven surface of this layer generates a mechanical scraping effect during material movement, preventing tar and particulate matter from adhering.

[0036] The filter guide layer is composed of three layers of metal wire mesh with different mesh sizes: 20 mesh, 50 mesh, and 100 mesh 316L stainless steel wire mesh from the inside out, with each layer being 1mm thick. This layer maintains the tar level above the tar dew point through the conduction of high-temperature flue gas from the outer layer, preventing tar from condensing and solidifying to clog the mesh pores, thus achieving graded interception and condensation of tar droplets and particulate matter for reflux.

[0037] The structural support layer is made of 8mm thick steel plate with 8mm diameter flue gas passage holes, with an opening rate of 25%, which uniformly introduces the purified pyrolysis gas into the high-temperature combustion chamber.

[0038] As the pyrolysis gas passes through the wall, it sequentially passes through the contact material layer, the filter and guide layer, and the structural support layer. Tar droplets and particulate matter are intercepted and condensed in the wire mesh layer and flow back into the pyrolysis carbonization chamber, while the clean pyrolysis gas enters the high-temperature combustion chamber through the flue gas passage. This design ensures efficient removal of tar and particulate matter from the pyrolysis gas before it leaves the pyrolysis carbonization chamber, eliminating the need for additional pyrolysis gas purification equipment.

[0039] Three thermocouples are evenly arranged along the axial direction inside the pyrolysis carbonization chamber to monitor the temperature at the feed end. Central temperature and discharge end temperature In this embodiment, during stable operation... , , .

[0040] The solid carbonized material produced by the pyrolysis reaction is discharged from the bottom of the pyrolysis carbonization chamber through a water-cooled screw conveyor. After collection, it can be used to prepare biochar-based fertilizer.

[0041] S3: Pyrolysis gas combustion and flue gas recirculation The pyrolysis gas enters the high-temperature combustion chamber, which is a vertical cylindrical structure and is coaxially nested with the pyrolysis carbonization chamber. The pyrolysis carbonization chamber is located in the inner layer, and the high-temperature combustion chamber is located in the outer jacket.

[0042] A swirl burner is installed at the bottom of the high-temperature combustion chamber. After the pyrolysis gas enters through the central tube, it forms a rotating airflow through adjustable-angle guide vanes. The angle of the guide vanes can be adjusted from 15° to 45°. In this embodiment, the angle of the guide vanes is set to 30°.

[0043] The combustion air, after being preheated by the waste heat recovery unit, is divided into two paths: Primary air accounts for 25% of the total air volume and is injected into the swirl burner through the primary air ring, where it is premixed with the pyrolysis gas to form a fuel-rich zone. Secondary air accounts for 75% of the total air volume. It is injected from the middle of the combustion chamber through the secondary air ring and mixes with the unburned gas to achieve complete combustion.

[0044] In this embodiment, the ratio of primary air to secondary air is as follows: Set to 25%.

[0045] A high-temperature flue gas recirculation channel is installed at the top of the high-temperature burnout chamber. This channel has an annular gas collection hood structure and is connected to the bottom inlet of the high-temperature burnout chamber via a recirculation pipe. An electrically operated regulating valve is installed on the recirculation pipe to control the amount of recirculated flue gas. The recirculated flue gas is mixed with fresh pyrolysis gas before entering the swirl burner. The recirculation ratio is adjusted by regulating the valve opening. It has stabilized at 30%.

[0046] Three thermocouples are installed inside the high-temperature combustion chamber: the bottom combustion zone Central main combustion zone Upper Exit Area In this embodiment, , , Combustion temperature controlled at 900 Up to 1200 During this process, the flue gas remains in the high-temperature zone for more than 2 seconds to ensure complete decomposition of organic matter.

[0047] An online gas analyzer is installed on the pyrolysis gas pipeline to monitor the carbon monoxide content in the pyrolysis gas in real time. Hydrogen content and methane content In this embodiment, , , Total combustible gas content It is 45%.

[0048] when When the temperature drops below 40%, the system automatically adjusts the pyrolysis temperature. Increase by 20 Or reduce the feeding speed Reduced by 10%; when When the temperature exceeds 55%, the system will automatically adjust the pyrolysis temperature. Reduce by 20 Or reduce the feeding speed Increase by 10%.

[0049] S4: Waste heat recovery in stages The heat gradient utilization in this process follows the principle of temperature matching: 1100 The above high-temperature sections are used for pyrolysis gas combustion and heating of the pyrolysis carbonization chamber; 650 Up to 1100 The medium and high temperature sections are used to preheat the combustion air; 150 Up to 650 The medium-temperature section is used to dry the materials fed into the furnace; 150 The following low-temperature sections are discharged after purification.

[0050] Through this tiered utilization, the system's thermal efficiency can reach over 85%.

[0051] The high-temperature flue gas generated in the high-temperature burnout chamber is first introduced into the external heating jacket of the pyrolysis carbonization chamber. The high-temperature burnout chamber and the external heating jacket of the pyrolysis carbonization chamber are connected, and the high-temperature flue gas flows within the external heating jacket, providing heat for the pyrolysis reaction through indirect heat exchange.

[0052] The flue gas flows in a spiral path within the external heating jacket to increase the heat exchange length and time. After heat exchange, the flue gas temperature drops to 650°C. It becomes medium-temperature flue gas.

[0053] The intermediate-temperature flue gas then enters the waste heat recovery unit, which consists of two heat exchangers connected in series. The first-stage heat exchanger is a plate-type gas-to-gas heat exchanger, used to preheat the combustion air from ambient temperature (20°C). Preheat to 120 ; The second-stage heat exchanger is a rotary gas-solid dryer used to dry the materials fed into the furnace, reducing the moisture content of crushed, diseased, and dead animal materials from 68% to below 15%. The flue gas temperature drops to 150°C after heat exchange in the waste heat recovery unit. The following is the low-temperature flue gas.

[0054] S5: Flue Gas Purification and Emission The low-temperature flue gas enters the flue gas purification unit, which includes a quench tower, a dry acid removal tower, and a bag filter. The low-temperature flue gas first enters the quench tower, where its temperature is reduced to 200°C within one second. The following inhibits dioxin resynthesis; Then it enters the dry deacidification tower, where slaked lime and activated carbon are sprayed in to remove acidic gases and adsorb heavy metals; Finally, the flue gas enters the bag filter to remove dust. The purified flue gas is then discharged through a chimney by an induced draft fan, meeting emission standards.

[0055] S6: Coordinated Control of Energy Balance and Process Parameters The core of this process lies in utilizing the heat generated by the combustion of pyrolysis gas to maintain the energy required for the pyrolysis reaction and material drying, thereby achieving energy self-sufficiency.

[0056] During the stable operation phase, the intelligent control system coordinates and adjusts multiple parameters accordingly. , , , , , , Based on the detected values, a combined feedforward and feedback control strategy is adopted to automatically adjust the feeding speed. pyrolysis temperature Primary wind to secondary wind ratio and the proportion of high-temperature flue gas recirculation .

[0057] The adjustment range is determined based on experimental analysis of the system's dynamic response characteristics. Let... With target value The deviation is ,when At that time, the control system adjusts according to the following rules: like This indicates that the temperature is too low, so the feed rate should be reduced. reduce At the same time Increase by 1 percentage point The maximum adjustment range shall not exceed 20% and 10 percentage points; like This indicates that the temperature is too high, so the feed rate should be reduced. improve At the same time Lower by 1 percentage point The maximum adjustment range shall not exceed 20% and 10 percentage points.

[0058] The temperature control rules for the high-temperature combustion chamber are as follows: when Above 1100 At that time, the proportion of high-temperature flue gas recirculation Increase by 5 percentage points; when Below 950 At that time, the proportion of high-temperature flue gas recirculation Reduced by 5 percentage points; when Restored to 1000 Up to 1080 After the interval, it will be increased at a rate of 1 percentage point per minute. Gradually revert to the initial setting of 30%.

[0059] The quality control rules for pyrolysis gas are as follows: when When the content is below 40%, the pyrolysis temperature will be lowered. Increase by 20 and the feeding speed Reduced by 10%; when When it is above 55%, the pyrolysis temperature will be... Reduce by 20 and the feeding speed Increase by 10%.

[0060] The material drying control rules are as follows: when When the material residence time in the second-stage heat exchanger is above 70%, the residence time can be extended by 15% by reducing the rotational dryer speed. when When the concentration is below 50%, the material residence time in the second-stage heat exchanger is reduced by 15%, which is achieved by increasing the rotation speed of the rotary dryer.

[0061] Through the above-mentioned coordinated control, after the system is running stably, the heat generated by the combustion of pyrolysis gas in S2 is fully sufficient to meet the heat required for the pyrolysis reaction in S1 and the material drying in S4, without the need for external auxiliary fuel, thus achieving energy self-sufficiency.

[0062] System startup and shutdown process: When the system starts up, the auxiliary burner is first started to preheat the high-temperature combustion chamber to 800°C. That's all, then start feeding.

[0063] In the initial stage, the pyrolysis gas yield and calorific value are low. The auxiliary burner continues to operate until the heat generated by the combustion of the pyrolysis gas is sufficient to sustain the system's operation. The start-up time depends on the material moisture content and ambient temperature, ranging from 2 to 4 hours.

[0064] When the system is shut down, first stop feeding, and after all the material in the pyrolysis and carbonization chamber has been discharged, gradually reduce the combustion temperature, and finally stop the blower and auxiliary equipment.

[0065] Security protection mechanism: The system is equipped with multiple safety protections: If the high-temperature combustion chamber temperature exceeds the equipment's design temperature limit of 1250°C... Automatically increase the reflux ratio And reduce the feeding speed ; The explosion-proof valve will automatically open when the pressure inside the pyrolysis carbonization chamber exceeds 1.2 times (5000Pa) of the design working pressure; When the oxygen concentration in the pyrolysis carbonization chamber exceeds 5%, nitrogen is automatically introduced for inerting; when the fan fails, the feed is automatically cut off and the bypass flue is opened.

[0066] Example 2: Processing technology for the disposal of carcasses of diseased and dead cattle This embodiment processes the carcasses of diseased and dead cattle, which have a high fat content. The process flow is basically the same as in Example 1, the difference being the parameter adjustments.

[0067] Detected in S1 , Because of its high fat content, the pyrolysis reaction releases a large amount of heat, therefore the pyrolysis temperature is... The default value is 620. The pyrolysis time is 90 minutes.

[0068] S2 feeding speed The speed is set at 300 kg / h. During the pyrolysis process, , , Stable at 600 620 610 .

[0069] Components of pyrolysis gas in S3: , , Total combustible gas content The primary air ratio is 50%. Due to its high calorific value, the primary air ratio is... Adjust to 20% to reduce initial combustion intensity; adjust the recirculation ratio. Adjust to 25% to control the combustion zone temperature. High-temperature burnout chamber temperature monitoring value: , , .

[0070] In S4, the combustion air is preheated to 100°C. After drying, the moisture content of the material decreased to 12%.

[0071] All the above parameter adjustments are made by the control system. , The detection value and the control logic described in S6 are completed automatically without manual intervention.

[0072] Example 3: Processing technology for handling carcasses of diseased and dead poultry This embodiment processes carcasses of diseased or dead poultry, which have a high moisture content. The process flow is adjusted as follows: Detected in S1 , Preset pyrolysis temperature The pyrolysis time is 40 minutes.

[0073] S2 feeding speed During pyrolysis , , .

[0074] Components of pyrolysis gas in S3: , , Total combustible gas content The calorific value is 34%. Due to the low calorific value, the feed rate is reduced. Reduce the flow rate to 700 kg / h, and lower the pyrolysis temperature. Increased to 540 .

[0075] At the same time, the primary wind ratio Adjust to 30% to enhance initial combustion; recirculation ratio Maintain at 30%. High-temperature burnout chamber temperature monitoring value: , , .

[0076] In S4, the combustion air is preheated to 80°C. After drying, the moisture content of the material decreased to 14%.

[0077] All the above parameter adjustments are made by the control system. , The detection value and the control logic described in S6 are completed automatically without manual intervention.

[0078] Comparing Examples 1 to 3, it can be seen that material properties significantly affect the process parameter settings: High fat content materials ( High calorific value, needs to be reduced and To control the intensity of combustion; High moisture content materials ( The calorific value is low and needs to be increased. and This ensures complete pyrolysis. This demonstrates the adaptability of this process to different materials; the control system can adjust based on real-time monitoring data. and Automatic parameter adjustment.

[0079] Example 4: Verification of Energy Self-Sustaining Operation This embodiment demonstrates the energy balance state of the system after stable operation. Based on the parameters of Embodiment 1, after 24 hours of continuous operation, the key data are recorded as follows: Average temperature of pyrolysis carbonization chamber Average temperature of high-temperature combustion chamber Feeding speed .

[0080] The mass flow rate of pyrolysis gas was directly measured to be 300 kg / h by a mass flow meter installed on the pyrolysis gas pipeline, accounting for 60% of the feed material mass of 500 kg / h.

[0081] The lower heating value of the pyrolysis gas was directly measured to be 15.2 MJ / kg using an online gas analyzer and a calorific value analyzer.

[0082] The total heat released by the combustion of pyrolysis gas is .

[0083] Heat required for pyrolysis reaction: Based on experimental data of the material's pyrolysis characteristics, the heat required for the material to rise from room temperature to 600°C... The heat required for the pyrolysis reaction is 2.6 MJ / kg of material, i.e. .

[0084] Heat required for material drying: Assuming the initial moisture content is 100%. The target moisture content is The amount of water evaporated The calculation formula is: ; Assuming a flow rate of 312 kg / h, and a latent heat of vaporization of 2.26 MJ per kilogram of water, the required heat is... .

[0085] According to the system thermal balance test, heat loss Including sensible heat loss from flue gas and wall heat loss : ; According to calculations, It accounts for approximately 35% of the total heat of combustion, that is .

[0086] The effective utilization of heat is It is greater than the sum of the heat required for pyrolysis and drying. Therefore, there is an excess heat of 959 MJ / h that can be recovered for heating in the factory area, and the system is fully self-sufficient in energy.

[0087] Example 5: Adaptive Adjustment Process under Different Operating Conditions This embodiment demonstrates the specific process by which the control system automatically adjusts process parameters based on detected values. Assume the following data is detected at a certain moment: , , , , .

[0088] The control system performs coordinated adjustment according to the following steps: First step, because Below the target value (current )and When the temperature drops below 40%, the control system will lower the pyrolysis temperature. Increase by 20 Up to 600 At the same time, the feeding speed Reduce by 10% to 450 kg / h; The second step, because Above 1100 The control system will recirculate a certain proportion of high-temperature flue gas. Increased from 30% to 35%; The third step is monitoring. Changes, 15 minutes later Rebounded to 575 The control system suspends further adjustments; Step 4, monitoring Changes, 10 minutes later Reduced to 1080 Enter 1000 Up to 1080 Within the interval, the control system will adjust at a rate of 1 percentage point per minute. Gradually pulled back to 32%; Fifth step, when After recovering to over 45%, the control system will operate at 5... The rate of / min will Gradually pullback to 580 The feed rate is increased to 10 kg / h / min. Restored to 500 kg / h.

[0089] The entire adjustment process was completed within 45 minutes, and the system returned to stable operating conditions without human intervention.

[0090] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A process for integrated carbonization incineration-waste heat recovery of dead animals, characterized in that, Includes the following steps: S1: Place the dead animal material in the pyrolysis and carbonization chamber and carry out the pyrolysis reaction in an oxygen-deficient environment to generate pyrolysis gas and solid carbonized material. S2: The pyrolysis gas is introduced into the high-temperature combustion chamber, mixed with preheated combustion air, and then burned to generate high-temperature flue gas; S3: The high-temperature flue gas is introduced into the external heating jacket of the pyrolysis carbonization chamber to provide heat to the pyrolysis carbonization chamber through indirect heat exchange; S4: The flue gas after heat exchange in the pyrolysis and carbonization chamber enters the waste heat recovery unit, where it is used to preheat the combustion air and dry the materials entering the furnace in sequence. S5: The low-temperature flue gas after heat exchange in the waste heat recovery unit enters the flue gas purification unit for treatment before being discharged. The pyrolysis carbonization chamber and the high-temperature burnout chamber are arranged in a coaxial nested structure, with the pyrolysis carbonization chamber located in the inner layer and the high-temperature burnout chamber located in the outer jacket. A flue gas channel is provided on the wall of the pyrolysis carbonization chamber to connect with the high-temperature burnout chamber. The flue gas channel introduces the pyrolysis gas into the high-temperature burnout chamber and retains the solid carbonized material in the pyrolysis carbonization chamber.

2. The process according to claim 1, characterized in that, The wall of the pyrolysis carbonization chamber described in S1 consists of a contact material layer, a filter and flow guiding layer and a structural support layer from the inside out. The contact material layer is made of a porous corrugated plate. The filter and flow guiding layer is composed of at least two layers of metal wire mesh with different mesh counts. The mesh count of the metal wire mesh near the inner layer is smaller than that near the outer layer. The pyrolysis gas passes sequentially through the contact material layer, the filter and guide layer, and the structural support layer before entering the high-temperature combustion chamber.

3. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 1, characterized in that, The pyrolysis gas mentioned in S2 enters the bottom of the high-temperature combustion chamber and forms a rotating airflow. The rotating airflow is guided by guide vanes, and the angle of the guide vanes is adjustable. The pyrolysis gas is mixed and burned sequentially with primary air and secondary air, wherein the primary air accounts for 20% to 30% of the total combustion air and the secondary air accounts for 70% to 80% of the total combustion air.

4. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 3, characterized in that, S2 also includes a flue gas recirculation step: a portion of the high-temperature flue gas in the upper part of the high-temperature burnout chamber is led back to the bottom of the high-temperature burnout chamber through a recirculation channel, mixed with the pyrolysis gas that enters, and then burned. The amount of recirculated flue gas accounts for 20% to 35% of the total amount of flue gas in the high-temperature burnout chamber.

5. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 1, characterized in that, S1 is preceded by a material inspection step: The composition of the dead animal material was analyzed online to obtain the moisture content value. The ratio of fat to protein mass was measured. ; The pyrolysis temperature setpoint of the pyrolysis carbonization chamber mentioned in S1 and material residence time according to the above and stated Adjustments will be made.

6. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 5, characterized in that, S2 also includes a gas monitoring step: Regarding the carbon monoxide content in the pyrolysis gas Hydrogen content and methane content Conduct online monitoring; when When the content is below 40%, the pyrolysis temperature will be lowered. Increase by 20 Or reduce the feeding speed Reduced by 10%; when When it is above 55%, the pyrolysis temperature will be... Reduce by 20 Or reduce the feeding speed Increase by 10%.

7. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 1, characterized in that, The waste heat recovery unit in S4 includes a first-stage heat exchanger and a second-stage heat exchanger. The first-stage heat exchanger preheats the combustion air to 80°C. Up to 150 The second-stage heat exchanger dries the furnace feed material to a moisture content of less than 15%.

8. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 1, characterized in that, The combustion temperature of the high-temperature burnout chamber described in S2 is controlled at 900°C. Up to 1200 The residence time of the flue gas is greater than 2 seconds. The high-temperature combustion chamber is equipped with a bottom temperature monitoring point, a middle temperature monitoring point, and an upper temperature monitoring point, which are used to monitor the temperature of the combustion chamber. , and .

9. The integrated process for carbonization and incineration of diseased and dead animals with waste heat recovery according to claim 1, characterized in that, It also includes control steps: Set the temperature monitoring value in the middle of the pyrolysis carbonization chamber. With pyrolysis temperature setpoint The deviation is ,when When adjusting, follow these rules: like , increase the feeding speed reduce At the same time, the ratio of primary wind to secondary wind is adjusted. Increase by 1 percentage point The maximum adjustment range shall not exceed 20% and 10 percentage points; like , increase the feeding speed improve At the same time Lower by 1 percentage point The maximum adjustment range shall not exceed 20% and 10 percentage points; When the temperature monitoring value in the middle of the high-temperature combustion chamber Above 1100 At that time, the proportion of high-temperature flue gas recirculation Increase by 5 percentage points; when Below 950 At that time, Reduced by 5 percentage points; when Restored to 1000 Up to 1080 After the interval, it will be increased at a rate of 1 percentage point per minute. Gradually revert to the initial setting value.

10. The integrated process for carbonization and incineration of diseased and dead animals and waste heat recovery according to any one of claims 1 to 9, characterized in that, The heat generated by the combustion of the pyrolysis gas in S2 sustains the heat required for the pyrolysis reaction in S1 and the drying of the material fed into the furnace in S4.

Images