Medical sludge incineration method and device

Abstract

The present application relates to the technical field of medical sludge disposal technology, and discloses a medical sludge incineration method and device, which is realized based on a medical waste incineration system with an incinerator and a secondary combustion chamber; medical sludge is dried to dry medical sludge particles with a water content of less than 30wt%, and then the dry medical sludge particles are mixed into medical waste at a mass ratio of 1:9-1:3 and incinerated together with the medical waste; wastewater generated during the drying process is collected and treated through a wastewater collection tank, and waste gas generated during the drying process is collected and transported for treatment through a waste gas conveying pipeline.In the present application, the medical sludge is mixed and burned in the original medical waste incineration system through a specific mixing and burning method, which not only has little effect on the original burning, but also can synergistically reduce the concentration of tail gas pollutants in the original medical waste incineration system; it is also conducive to reducing the calorific value of the medical waste mixture, improving the disposal capacity of the incineration system, and saving the treatment cost of medical sludge.

Description

Technical Field

[0001] This invention relates to the field of medical sludge disposal technology, and in particular to a method and apparatus for incinerating medical sludge. Background Technology

[0002] With the significant increase in the production of medical sludge, the timely, safe, and proper disposal of medical wastewater sludge from healthcare institutions (hereinafter referred to as "medical sludge") is of great practical importance. The "Technical Guidelines for Hospital Wastewater Treatment" specifically defines medical sludge as sludge generated during hospital wastewater treatment and septic tank sludge, further categorizing it according to specific process names such as septic tank sludge, excess sludge, and digester sludge. Because different hospitals employ different wastewater treatment processes, medical sludge is generated at various stages. During hospital wastewater treatment, microorganisms survive in large numbers within the sludge through flocculation and adsorption. Due to the particularly complex composition of hospital wastewater, pathogenic microorganisms are likely to be present in the medical sludge.

[0003] Medical sludge is classified as hazardous waste and requires proper treatment and disposal. Currently, hospital wastewater treatment often prioritizes achieving water quality standards while neglecting sludge treatment and disposal. Sludge treatment primarily involves sludge thickening, dewatering, and off-site sludge cake removal. However, in engineering and operational practice, sludge treatment is often intermittent, leading to poor operation or even complete shutdown, resulting in sludge being directly discharged into septic tanks, removed, or even indiscriminately discharged into sewers. According to the "Medical Pollutant Discharge Standard," sludge generated by medical institutions should be centrally treated by qualified units. Currently, the cost of incinerating sludge for hazardous waste treatment is also high, leading to long-term stockpiling of medical sludge. Therefore, optimizing the treatment and disposal of medical sludge, simplifying disposal methods, and ensuring harmless treatment are of significant practical importance for promoting the innovative development of hospital wastewater treatment technologies.

[0004] Currently, the main methods for disposing of medical sludge include disinfection and incineration. Incineration is considered a relatively reliable method due to its advantages in volume reduction, resource recovery, and harmlessness. The applicant previously designed a medical waste incineration treatment device suitable for co-firing medical sludge, as detailed in utility model patent publication number CN214198691U. While this patent can achieve complete combustion of co-firing medical sludge, the low calorific value and high water content of medical sludge mean that indiscriminate co-firing can easily lead to accidental flameout and furnace shutdown, or even exceed standards for flue gas and pollutants. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for co-firing medical sludge that ensures stable combustion after co-firing and enhances the treatment capacity of the incineration system, thereby providing at least a beneficial option or creating conditions for solving one or more technical problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] This invention achieves simplified and harmless disposal of medical sludge by optimizing the design of medical sludge treatment and disposal. A method for incinerating medical sludge involves drying the medical sludge to a moisture content below 30 wt%, then mixing the dried medical sludge with medical waste at a mass ratio of 1:9 to 1:3 and incinerating it together. Since medical waste generally has a high calorific value, approximately 4500 to 5000 kcal / kg, excessively high calorific values ​​can cause excessively high temperatures in subsequent process stages, leading to the shutdown of the medical waste feeding system and reducing incineration capacity. However, after drying, the medical sludge with a moisture content below 30 wt% has a lower calorific value than medical waste, approximately 2000 to 3000 kcal / kg. By co-firing a specific proportion of medical sludge, the calorific value of the medical waste mixture is reduced, improving the incineration system's capacity and avoiding high-temperature shutdowns; simultaneously, it can save on medical sludge treatment costs.

[0008] Specifically, the process for treating dried medical sludge includes front-end disinfection, dewatering, transportation, and low-temperature drying. Front-end disinfection and dewatering are completed at the medical sludge collection point, such as hospitals, while low-temperature drying is completed at a medical waste incineration plant.

[0009] In the aforementioned front-end disinfection step, lime is added to the medical sludge to adjust the pH value to above 11.5.

[0010] In the dewatering step, activated carbon (1%–3% by weight), coagulant (3%–8% by weight), and flocculant (0.1%–0.5% by weight) are added to the disinfected medical sludge for conditioning. The conditioned and concentrated sludge is then dewatered by filter press, yielding filtrate and medical sludge with a moisture content of 80±5%. The filtrate is recycled for further conditioning, while the medical sludge is transported off-site. Adding a certain proportion of activated carbon in the conditioning step not only adsorbs odors and reduces their emission but also increases the co-firing ratio.

[0011] In the aforementioned transportation step, a transfer vehicle is used to load turnover boxes for sealed transportation to prevent the spread of medical waste germs and toxic gases. When loading turnover boxes onto the transfer vehicle, more than 1 / 4 of the space inside the vehicle is reserved to ensure the circulation of air inside the vehicle, which facilitates disinfection and refrigeration.

[0012] The low-temperature drying step is carried out in a medical waste incineration plant. The high-temperature waste heat generated by the medical waste incineration system is sent to a low-temperature drying device for medical sludge via an induced draft fan, providing heat for the low-temperature drying of the medical sludge. The medical sludge in the transfer box is poured into the low-temperature drying device to obtain dried sludge particles. Wastewater generated during the drying process enters a wastewater treatment system, which includes a wastewater collection tank, an equalization tank, a flocculation sedimentation tank, an intermediate water tank, an MBR biological treatment tank, an RO reverse osmosis tank, and a clear water disinfection tank connected in sequence. In this way, all wastewater treated by the wastewater treatment system can be reused without external discharge. Exhaust gas generated during the drying process enters an exhaust gas treatment system, which includes an alkaline scrubbing spray tower, a water scrubbing spray tower, a UV photolysis exhaust gas treatment device, and an activated carbon adsorption device connected in sequence. The exhaust gas is treated by the exhaust gas treatment system and discharged in compliance with standards. A high exhaust stack of at least 15 meters is used when discharging the treated exhaust gas to reduce the environmental impact of the exhaust gas.

[0013] In some embodiments, the medical sludge low-temperature drying device uses a dedicated heat source instead of the high-temperature waste heat generated by the medical waste incineration system, which leads to increased energy consumption.

[0014] In some embodiments, the exhaust gas generated during the medical sludge transfer and drying process is introduced into the secondary combustion chamber through the air inlet duct and incinerated along with supplemental air. The sludge wastewater and sludge drying steam condensate generated during the medical sludge transfer and drying process are sprayed into the secondary combustion chamber through atomizing nozzles for incineration. This can fundamentally avoid the emission of exhaust gas and wastewater.

[0015] On the other hand, the present invention also provides a medical sludge incineration device for implementing the medical sludge incineration method described above, comprising: a medical sludge low-temperature drying mechanism, a wastewater collection tank, an exhaust gas conveying pipeline, and an incineration mechanism; the medical sludge low-temperature drying mechanism is used to achieve low-temperature drying of medical sludge; the wastewater collection tank is used to collect wastewater generated during the low-temperature drying process of medical sludge; the exhaust gas conveying pipeline is used to collect and convey exhaust gas generated during the low-temperature drying process of medical sludge; the incineration mechanism has an incinerator and a secondary combustion chamber for co-firing medical sludge and medical waste and providing the heat required for drying of the medical sludge low-temperature drying mechanism.

[0016] In this invention, the low-temperature drying of medical sludge is carried out in a negative pressure chamber, and the waste gas conveying pipeline is used to collect and convey waste gas from the negative pressure chamber, the sludge storage room, and the dried sludge storage chamber.

[0017] In one embodiment, the medical sludge incineration device provided by the present invention further includes a waste gas treatment system. The waste gas conveying pipeline collects and conveys waste gas to the waste gas treatment system. The waste gas treatment system includes an alkaline washing spray tower, a water washing spray tower, a UV photolysis waste gas treatment device, an activated carbon adsorption device, an exhaust fan, and a high exhaust stack connected in sequence. The exhaust height of the high exhaust stack is more than 15 meters.

[0018] In one embodiment, the medical sludge incineration device provided by the present invention further includes a wastewater treatment system. Wastewater in the wastewater collection tank enters the wastewater treatment system for treatment. The wastewater treatment system includes an equalization tank, a flocculation sedimentation tank, an intermediate water tank, an MBR biochemical tank, an RO reverse osmosis tank, and a clean water disinfection tank connected in sequence. In this way, the wastewater treated by the wastewater treatment system can be completely reused without being discharged.

[0019] In one embodiment, the waste gas conveying pipeline collects and conveys waste gas to the air supply pipeline of the secondary combustion chamber for incineration, while wastewater from the wastewater collection tank is sprayed into the secondary combustion chamber for incineration via atomizing nozzles. This eliminates the need for additional waste gas and wastewater treatment devices, resulting in zero wastewater discharge and ensuring high safety. By collecting the waste gas and wastewater generated during the medical sludge transfer process using a waste gas and wastewater collection device and co-firing it into the secondary combustion chamber using the same method, zero waste gas and wastewater discharge can be achieved throughout the entire medical sludge collection and transfer chain.

[0020] In one embodiment, the medical sludge low-temperature drying mechanism includes a drying chamber, a waste heat module, a material spreading device, a chain conveyor belt, and a circulating fan. The drying chamber and the waste heat module are connected by an air circulation pipe, and the circulating fan is installed on the air circulation pipe to provide air circulation power. The waste heat module is used to cool and remove water from the humid hot air discharged from the drying chamber, and then heat it up to become dry hot air and send it back to the drying chamber, realizing hot air circulation and sludge dehumidification. The material spreading device is used to arrange the medical sludge to be dried on the chain conveyor belt located in the drying chamber. The chain conveyor belt is driven by a frequency converter and rotates in a cycle, and the spreading speed of the material spreading device controls the spreading thickness and drying time of the sludge.

[0021] In one embodiment, the fabrication device includes an agitator and an extrusion molding roller arranged vertically and connected in sequence. The agitator is used to mix and stir the medical sludge, and the extrusion molding roller is used to form the medical sludge into sludge particles to improve the uniformity of drying.

[0022] In one embodiment, the fabric feeding device controls the fabric speed through a corresponding frequency conversion control device.

[0023] In one embodiment, a waste heat boiler, a composite acid removal tower, a bag filter, and a wet acid removal tower are sequentially connected to the exhaust gas outlet of the secondary combustion chamber. The waste heat boiler is connected to a medical sludge low-temperature drying mechanism to provide the heat required for the low-temperature drying of the medical sludge. The composite acid removal tower, the bag filter, and the wet acid removal tower together constitute an exhaust gas treatment mechanism to ensure that the incineration flue gas meets emission standards.

[0024] The present invention adopts the above technical solution and has at least the following advantages and beneficial effects.

[0025] In this invention, sludge is co-burned in the original medical waste incineration system through a specific co-burning method. This not only has little impact on the original combustion, but also synergistically promotes the reduction of pollutant concentration in the incineration exhaust gas of the original medical waste incineration system. It also helps to reduce the calorific value of the medical waste mixture, improve the disposal capacity of the incineration system, and save on the treatment cost of medical sludge.

[0026] Some other beneficial effects of the present invention will become more apparent in the following description or may be learned by practice. Attached Figure Description

[0027] Figure 1 The diagram shown is a schematic diagram of the medical incineration device provided in Embodiment 1 of the present invention.

[0028] Figure 2 The diagram shown is a flowchart of the medical sludge drying and co-firing process provided in Embodiment 1 of the present invention.

[0029] Figure 3 The diagram shown is a wastewater treatment process flow chart according to Embodiment 1 of the present invention.

[0030] Figure 4 The diagram shown is a flow chart of the waste gas treatment process in Embodiment 1 of the present invention.

[0031] Figure 5 The diagram shown is a flowchart of the medical sludge drying and co-firing process provided in Embodiment 2 of the present invention.

[0032] Figure 6 The diagram shown is a schematic diagram of the medical sludge incineration device provided in Embodiment 2 of the present invention.

[0033] Figure 7 The image shows dried medical sludge particles.

[0034] Explanation of the reference numerals in the attached figures.

[0035] 1: Low-temperature drying mechanism for medical sludge; 2: Incineration mechanism; 3: Negative pressure chamber; 4: Waste gas transmission pipeline; 5: Wastewater treatment system; 6: Waste gas treatment system.

[0036] 201: Incinerator; 202: Secondary combustion chamber; 203: Atomizing nozzle; 204: Waste heat boiler; 205: Composite acid removal tower; 206: Bag filter; 207: Wet acid removal tower.

[0037] 501: Wastewater collection tank; 502: Equalization tank; 503: Flocculation sedimentation tank; 504: Intermediate water tank; 505: MBR biological treatment tank; 506: RO reverse osmosis tank; 507: Clear water disinfection tank.

[0038] 601: Alkali washing spray tower; 602: Water washing spray tower; 603: UV photolysis waste gas treatment equipment; 604: Activated carbon adsorption equipment; 605: Exhaust fan; 606: High exhaust stack. Detailed Implementation

[0039] The specific embodiments of the present invention will be further described below to make the technical solution and its beneficial effects clearer and more explicit. The embodiments described below are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0040] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention.

[0041] Example 1.

[0042] A method for pretreatment of medical sludge includes front-end disinfection, dewatering and off-site transportation steps, wherein front-end disinfection and dewatering are completed at the medical sludge collection point in hospitals or other facilities.

[0043] In the aforementioned front-end disinfection step, lime is added to the medical sludge to adjust the pH value to above 11.5.

[0044] In the dewatering step, activated carbon (2% by weight), coagulant (5% by weight), and flocculant (0.3% by weight) are added to the disinfected medical sludge for conditioning. The conditioned and concentrated sludge is then dewatered by filter press, yielding filtrate and medical sludge with a moisture content of 80±5%. The filtrate is recycled for further conditioning, while the medical sludge is transported off-site. Adding a certain proportion of activated carbon in the conditioning step not only adsorbs odors and reduces their emission but also increases the co-firing ratio.

[0045] In the aforementioned transportation step, a transfer vehicle is used to load turnover boxes for sealed transportation to prevent the spread of medical waste germs and toxic gases. When loading turnover boxes onto the transfer vehicle, more than 1 / 4 of the space inside the vehicle is reserved to ensure the circulation of air inside the vehicle, which facilitates disinfection and refrigeration.

[0046] Example 2.

[0047] Reference Figure 1 As shown, a medical sludge incineration device includes a medical sludge low-temperature drying mechanism 1 and an incineration mechanism 2. The medical sludge low-temperature drying mechanism 1 is used to perform low-temperature drying on the medical sludge pretreated in Example 1. The incineration mechanism 2 is used to incinerate the medical sludge and provide the heat required for drying to the medical sludge low-temperature drying mechanism 1.

[0048] Combination Figures 2-4 As shown, the dried sludge obtained after being dried and dewatered by the medical sludge low-temperature drying unit 1 is mixed with medical waste and sent to the incinerator 201 of the incineration unit 2 for high-temperature combustion. Wastewater generated during the medical sludge drying process enters the wastewater treatment system 5. The wastewater treatment system 5 includes a wastewater collection tank 501, an equalization tank 502, a flocculation sedimentation tank 503, an intermediate water tank 504, an MBR biological treatment tank 505, an RO reverse osmosis tank 506, and a clean water disinfection tank 507, connected in sequence. Thus, the wastewater treated by the wastewater treatment system can be completely reused without external discharge. The exhaust gas generated during the drying process enters the exhaust gas treatment system 6. The exhaust gas treatment system 6 includes an alkaline scrubbing spray tower 601, a water scrubbing spray tower 602, a UV photolysis exhaust gas treatment device 603, and an activated carbon adsorption device 604, connected in sequence. After treatment by the exhaust gas treatment system, the exhaust gas is drawn by the exhaust fan 605 to the high-level exhaust stack 606 to achieve compliant emissions. When discharging treated waste gas, a high exhaust stack of 15 meters or more is selected to reduce the environmental impact of the waste gas. In this embodiment, the low-temperature drying of medical sludge is carried out in a negative pressure chamber 3, and the air in the negative pressure chamber 3 is drawn into the waste gas treatment system 6 through the waste gas conveying pipe 4.

[0049] In this embodiment, the medical sludge low-temperature drying mechanism 1 includes a drying chamber, a waste heat module, a material distribution device, a chain conveyor belt, and a circulating fan. The drying chamber and the waste heat module are connected by an air circulation pipe, and the circulating fan is installed on the air circulation pipe to provide air circulation power. The waste heat module is used to cool and remove water from the humid hot air discharged from the drying chamber, and then heat it up to become dry hot air and send it back to the drying chamber, realizing hot air circulation and sludge dehumidification. The material distribution device is used to arrange the medical sludge to be dried on the chain conveyor belt located in the drying chamber. The chain conveyor belt circulates under the drive of a frequency converter, and the material distribution speed of the material distribution device controls the material thickness and drying time of the sludge to ensure that the moisture content of the dried medical sludge is less than 30 wt%. The dried medical sludge obtained in this embodiment is as follows: Figure 7 As shown, the measured moisture content is 20 wt%.

[0050] In some embodiments, the fabrication device includes an agitator and an extrusion molding roller arranged vertically and connected in sequence. The agitator is used to mix and stir the medical sludge, and the extrusion molding roller is used to form the medical sludge into sludge particles to improve the uniformity of drying.

[0051] In some embodiments, the corresponding fabric-making device is equipped with a frequency conversion adjustment control device, which controls the fabric speed.

[0052] It should be noted that the specific structures of components such as the drying chamber, waste heat module, material distribution device, chain conveyor belt, and circulating fan, as well as their assembly structures, are common technical knowledge possessed by those skilled in the art and will not be elaborated upon here. Furthermore, the medical sludge low-temperature drying mechanism 1 is designed to achieve low-temperature drying of medical sludge. Those skilled in the art can employ other known sludge drying mechanisms to achieve the drying of medical sludge, depending on actual needs, and are not limited to this embodiment.

[0053] Combined Figure 1 As shown, a waste heat boiler 204, a composite acid removal tower 205, a bag filter 206, and a wet acid removal tower 207 are sequentially connected to the exhaust gas outlet of the secondary combustion chamber 202. The waste heat boiler 204 is connected to the medical sludge low-temperature drying mechanism 1 to provide it with the heat required for the low-temperature drying of medical sludge. The composite acid removal tower 205, the bag filter 206, and the wet acid removal tower 207 together constitute the exhaust gas treatment mechanism to ensure that the combustion flue gas meets the emission standards.

[0054] The medical sludge incineration device and method provided in this embodiment have the following technical advantages: Medical waste generally has a high calorific value, approximately 4500 to 5000 kcal / kg. This excessively high calorific value causes excessively high temperatures in subsequent process stages, leading to the shutdown of the medical waste feeding system and reducing incineration capacity. Medical sludge has a lower calorific value than medical waste, approximately 2000 to 3000 kcal / kg. By co-firing a certain proportion of medical sludge, the calorific value of the medical waste mixture can be reduced, improving the incineration system's processing capacity. Simultaneously, it can save on medical sludge treatment costs.

[0055] Example 3.

[0056] Reference Figure 5 , Figure 6 As shown, a medical sludge incineration device includes a medical sludge low-temperature drying mechanism 1 and an incineration mechanism 2. The medical sludge low-temperature drying mechanism 1 is used to perform low-temperature drying on the medical sludge pretreated in Example 1. The incineration mechanism 2 is used to incinerate the medical sludge and provide the heat required for drying to the medical sludge low-temperature drying mechanism 1.

[0057] Specifically, the dried sludge obtained after being dried and dehydrated by the medical sludge low-temperature drying unit 1 is mixed with medical waste and enters the incinerator 201 of the incineration unit 2 for high-temperature combustion. The exhaust gas generated during the drying and dehydration process of the medical sludge is sent to the secondary combustion chamber 202 of the incineration unit 2 through the secondary combustion chamber air inlet pipe for combustion. The sludge wastewater and sludge drying steam condensate generated during the drying and dehydration process of the medical sludge are sprayed into the secondary combustion chamber 202 for combustion through the atomizing nozzle 203.

[0058] The medical sludge incineration device and method provided in this embodiment have the following technical advantages: 1) Since medical waste generally has a high calorific value, approximately 4500 to 5000 kcal / kg, excessively high calorific value causes excessively high temperatures in subsequent process stages, leading to the shutdown of the medical waste feeding system and reducing incineration capacity. Medical sludge has a lower calorific value than medical waste, approximately 2000 to 3000 kcal / kg. By co-firing a certain proportion of medical sludge, the calorific value of the medical waste mixture can be reduced, improving the incineration system's capacity and saving on medical sludge treatment costs. 2) The waste gas and wastewater generated during the dehydration and drying process of medical sludge are incinerated together in the incineration unit 2, eliminating the need for additional waste gas and wastewater treatment devices, resulting in no wastewater discharge and good safety. In some embodiments, waste gas and wastewater generated during the medical sludge transfer process are collected by a waste gas and wastewater collection device and co-firing them into the secondary combustion chamber using the same method, achieving zero waste gas and wastewater discharge throughout the entire medical sludge collection and transfer chain.

[0059] In this embodiment, the specific structure of the medical sludge low-temperature drying mechanism 1 is the same as that in Embodiment 1, and will not be described again here.

[0060] In this embodiment, the low-temperature drying of medical sludge is carried out in a negative pressure chamber 3. Air in the negative pressure chamber 3 is drawn into the air supply pipe of the secondary combustion chamber 202 through the waste gas conveying pipe 4 and then incinerated in the secondary combustion chamber 202, thus avoiding the environmental risks caused by waste gas emissions during the low-temperature drying of medical sludge. The sludge wastewater and sludge drying steam condensate generated during the drying and dewatering process are sprayed into the secondary combustion chamber for incineration through atomizing nozzles 203. Run the test.

[0061] The following operational tests will be conducted to determine the optimal matching relationship between the amount of dried medical sludge co-firing and the incineration load of the medical waste incineration line, so as to provide a basis for subsequent operation and control.

[0062] Run test 1.

[0063] Based on Example 2, dried medical sludge was mixed with 10wt% of the medical waste input into the medical waste incineration line and co-incinerated, with online monitoring of flue gas data and incinerator operation.

[0064] Run test 2.

[0065] Based on Example 2, dried medical sludge was mixed with 15wt% of the medical waste input into the medical waste incineration line and co-incinerated, with online monitoring of flue gas data and incinerator operation.

[0066] Run test 3.

[0067] Based on Example 2, 20wt% of the medical waste input to the medical waste incineration line was mixed with dried medical sludge for co-incineration, and flue gas data and incinerator operation were monitored online.

[0068] Run test 4.

[0069] Based on Example 2, 25 wt% of the medical waste input to the medical waste incineration line was mixed with dried medical sludge for co-incineration, and flue gas data and incinerator operation were monitored online.

[0070] Run test 5.

[0071] Based on Example 2, dried medical sludge was mixed with 30wt% of the medical waste input into the medical waste incineration line and co-incinerated, with online monitoring of flue gas data and incinerator operation.

[0072] Run test 6.

[0073] Blank co-firing was used as a control group, and flue gas data were monitored online.

[0074] The flue gas monitoring data for each operational test are shown in Table 1.

[0075] Table 1. Flue gas monitoring data for each operational test.

[0076]

[0077] As can be seen from Table 1, the flue gas emission concentrations of each operation test can meet the emission standards, and the content of nitrogen oxides in the flue gas can be significantly reduced after co-firing medical sludge. However, when medical sludge is co-fired at 30wt% of the medical waste input of the medical waste incineration line, the content of carbon monoxide and hydrogen chloride in the flue gas increases significantly, indicating that the co-firing of medical sludge at 30wt% has an impact on the original combustion.

[0078] Table 2. Incinerator Operation Status.

[0079]

[0080] As shown in Table 2, when the co-firing amount of medical sludge is below 25 wt%, the furnace temperature and secondary combustion chamber temperature remain relatively stable, while the flue gas temperature rises slightly but not significantly. There are no significant differences in flue gas velocity, moisture content, and oxygen content. The dry standard flow rate of the flue gas decreases with increasing co-firing ratio. When the co-firing amount of medical sludge reaches 30 wt%, the furnace temperature drops significantly, and the incinerator may even experience flameout. Therefore, a co-firing amount of 15-25 wt% for medical sludge is the preferred range.

[0081] Run test 7.

[0082] Furthermore, to verify the impact of co-firing waste gas and wastewater into the secondary combustion chamber, a co-firing ratio of 20 wt% was implemented based on Example 3. Waste gas and wastewater generated online by the medical sludge drying facility were co-fired together in the secondary combustion chamber, and flue gas data were monitored online. The results are shown in Table 3.

[0083] Table 3. Comparison of flue gas monitoring data after co-firing waste gas and wastewater.

[0084]

[0085] As can be seen from Table 3, when the waste gas and wastewater generated online by the medical sludge drying facility are fed into the secondary combustion chamber for co-firing, the changes in flue gas data are not significant, the emission concentrations of the flue gas can meet the emission standards, and the content of nitrogen oxides in the flue gas even decreases after co-firing the waste gas and wastewater.

[0086] Run test 8.

[0087] Furthermore, to verify the impact of adding activated carbon to medical sludge, a co-firing scheme with a 20wt% ratio was designed based on Example 2. Medical sludge without activated carbon was used instead of the sludge with added activated carbon for co-firing, and flue gas data was monitored online. Other co-firing processes remained unchanged. The results are shown in Table 4.

[0088] Table 4. Comparison of flue gas monitoring data without added activated carbon.

[0089]

[0090] As can be seen from Table 4, when no activated carbon was added to the medical sludge, the content of carbon monoxide and nitrogen oxides in the flue gas increased significantly at a co-combustion ratio of 20 wt%, which may be due to incomplete combustion or fluctuations in combustion temperature.

[0091] It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Parts not described in the specific embodiments are all prior art or common knowledge.

Claims

1. A method for incinerating medical waste sludge, characterized in that, This is achieved using a medical waste incineration system with an incinerator and a secondary combustion chamber; medical sludge is dried to dry medical sludge particles with a moisture content of less than 30 wt%, and then the dried medical sludge particles are mixed into medical waste at a mass ratio of 1:9 to 1:3 and incinerated together with the medical waste. The drying process of medical sludge includes front-end disinfection, dewatering, transportation and low-temperature drying. Front-end disinfection and dewatering are completed at the medical sludge collection end, and low-temperature drying is completed at the medical waste incineration plant. Wastewater generated during the drying process is collected and treated through a wastewater collection pond, and waste gas generated during the drying process is collected and transported for treatment through a waste gas transmission pipeline.

2. The method for incinerating medical sludge according to claim 1, characterized in that, In the aforementioned front-end disinfection step, lime is added to the medical sludge to adjust the pH value to above 11.5; In the dewatering step, activated carbon (1% to 3% of the total weight of sludge), coagulant (3% to 8% of the total weight of sludge), and flocculant (0.1% to 0.5% of the total weight of sludge) are added to the disinfected medical sludge for conditioning. Then, the concentrated sludge after conditioning is dewatered by filter press to obtain filtrate and medical sludge with a moisture content of 80±5%. The filtrate is recycled for conditioning again, and the medical sludge is transported off-site. In the aforementioned transportation step, a transfer vehicle is used to load turnover boxes for sealed transportation to prevent the spread of medical waste germs and toxic gases. When loading turnover boxes onto the transfer vehicle, more than 1 / 4 of the space inside the vehicle is reserved to ensure the circulation of air inside the vehicle, which facilitates disinfection and refrigeration.

3. The method for incinerating medical sludge according to claim 1, characterized in that, Wastewater collected in the wastewater collection tank enters the wastewater treatment system, which includes a wastewater collection tank, an equalization tank, a flocculation sedimentation tank, an intermediate water tank, an MBR biological treatment tank, an RO reverse osmosis tank, and a clear water disinfection tank connected in sequence. All wastewater treated by the wastewater treatment system is reused and not discharged externally.

4. The method for incinerating medical sludge according to claim 1, characterized in that, The waste gas is collected and transported to the waste gas treatment system through the waste gas conveying pipeline. The waste gas treatment system includes an alkaline washing spray tower, a water washing spray tower, a UV photolysis waste gas treatment device and an activated carbon adsorption device connected in sequence. After being treated by the waste gas treatment system, the waste gas is discharged through a high exhaust stack of more than 15 meters.

5. The method for incinerating medical sludge according to claim 1, characterized in that, The exhaust gas is collected and transported to the secondary combustion chamber through the exhaust gas pipeline and then enters the secondary combustion chamber for incineration along with the supplementary air. The sludge and wastewater collected in the sewage collection tank are sprayed into the secondary combustion chamber for incineration through atomizing nozzles.

6. A medical sludge incineration device, characterized in that, A method for incinerating medical sludge as described in any one of claims 1-5 includes: a medical sludge low-temperature drying unit, a wastewater collection tank, an exhaust gas conveying pipeline, and an incineration unit; the medical sludge low-temperature drying unit is used to achieve low-temperature drying of medical sludge; the wastewater collection tank is used to collect wastewater generated during the low-temperature drying process of medical sludge; the exhaust gas conveying pipeline is used to collect and convey exhaust gas generated during the low-temperature drying process of medical sludge; the incineration unit has an incinerator and a secondary combustion chamber, used to achieve co-firing of medical sludge and medical waste and to provide the heat required for drying of the medical sludge low-temperature drying unit.

7. The medical sludge incineration device according to claim 6, characterized in that, The low-temperature drying of medical sludge is carried out in a negative pressure chamber, and the waste gas conveying pipeline is used to collect and convey waste gas from the negative pressure chamber, the sludge storage room and the dried sludge storage chamber.

8. A medical sludge incineration device according to claim 6, characterized in that, It also includes a waste gas treatment system. The waste gas conveying pipeline collects and conveys waste gas to the waste gas treatment system. The waste gas treatment system includes an alkaline washing spray tower, a water washing spray tower, a UV photolysis waste gas treatment device, an activated carbon adsorption device, an exhaust fan, and a high exhaust stack connected in sequence. The exhaust height of the high exhaust stack is more than 15 meters.

9. A medical sludge incineration device according to claim 6, characterized in that, It also includes a wastewater treatment system, in which the wastewater in the wastewater collection tank enters the wastewater treatment system for treatment. The wastewater treatment system includes an equalization tank, a flocculation sedimentation tank, an intermediate water tank, an MBR biological treatment tank, an RO reverse osmosis tank, and a clear water disinfection tank connected in sequence. All wastewater treated by the wastewater treatment system is reused and not discharged externally.

10. A medical sludge incineration device according to claim 6, characterized in that, The exhaust gas conveying pipeline collects and conveys exhaust gas to the air supply pipeline of the secondary combustion chamber for incineration. The sewage in the sewage collection tank is sprayed into the secondary combustion chamber for incineration through atomizing nozzles.

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