Medical waste pyrolysis system and pyrolysis method based on low-temperature pyrolysis

Abstract

The application discloses a medical waste pyrolysis system and a pyrolysis method based on low-temperature pyrolysis, which comprises a pyrolysis furnace, one end of the pyrolysis furnace is connected with a feeding unit, the other end of the pyrolysis furnace is connected with a slag discharging unit, the front end and the rear end of the pyrolysis furnace are respectively connected with a front distributor and a rear distributor, and the gas outlet of the front distributor and / or the rear distributor is connected with a burner; the burner is connected with the pyrolysis furnace for providing heat; and the burner is connected with a tail gas treatment device through a waste heat boiler. The medical waste is indirectly heated under an oxygen-free or oxygen-deficient working condition, the continuous endothermic and exothermic reactions are utilized, the organic components in the medical waste are subjected to thermal cracking and thermal chemical reactions, the original molecular structure is changed, the medical waste is changed into different phase-state substances, pyrolysis gas and pyrolysis carbon are generated, the continuous pyrolysis treatment of the medical waste is realized, the heat is recycled, and the cost is reduced; and the system has high comprehensive heat energy utilization rate and high waste resource utilization rate.

Description

Technical Field

[0001] This invention relates to the field of waste treatment technology, and in particular to a medical waste pyrolysis system and pyrolysis method based on low-temperature pyrolysis. Background Technology

[0002] Because medical procedures generate a large amount of waste, which is produced during patient diagnosis, treatment, and care, and may contain a large number of pathogenic microorganisms and harmful chemicals, and may even contain radioactive and damaging substances, medical waste must be strictly treated to eliminate its hazardous factors.

[0003] For the large quantities of medical waste generated, incineration is currently the most common method. Incineration has significant effects on sterilization and volume reduction, but existing technologies face the following bottlenecks that are difficult to solve: ① High-temperature incineration easily produces highly toxic substances such as dioxins and furans, causing serious secondary pollution; ② The treatment process converts almost all carbon elements in medical waste into gaseous state, leading to large carbon emissions; ③ Due to the toxicity of medical waste during incineration, the energy generated is not fully utilized, resulting in serious energy waste; ④ High-value intermediate products are directly incinerated at high temperatures, limiting the potential for resource recycling. Low-temperature pyrolysis technology is economical and efficient, with high energy utilization and resource recovery rates and low environmental pollution, making it one of the important methods for treating general solid waste. However, due to the high toxicity of medical waste and the complexity of low-temperature pyrolysis process control, it has not yet been engineered for medical waste treatment. Therefore, the development of low-temperature pyrolysis processes and supporting equipment for medical waste is urgently needed.

[0004] Chinese invention patent CN105737163A, published on July 6, 2016, discloses a low-temperature pyrolysis system for municipal solid waste and medical waste based on decoupled combustion. The pyrolysis section includes a drying drum and a pyrolysis drum, the gas scrubbing section includes a two-stage gas scrubbing tower, and the heat recovery section includes a waste heat recovery device for flue gas and pyrolysis gas. Municipal solid waste is first fed into the drying drum for drying, and then into the pyrolysis drum for pyrolysis to generate pyrolysis gas and charcoal residue. However, this system fails to achieve stepped heating in the pyrolysis furnace during the heating process, which is detrimental to improving the quality of pyrolysis products and saving energy. Furthermore, the system primarily generates pyrolysis gas and charcoal residue and lacks a sterilization system and a liquid separation system; therefore, it is not suitable for the low-temperature pyrolysis of medical waste, and its pyrolysis efficiency is low. Summary of the Invention

[0005] To address the shortcomings of the aforementioned background technology, this invention proposes a medical waste pyrolysis system and pyrolysis method based on low-temperature pyrolysis, which realizes continuous sterilization and continuous pyrolysis treatment of medical waste, with high comprehensive thermal energy utilization and reduced costs.

[0006] The technical solution of this invention is implemented as follows:

[0007] The medical waste pyrolysis system based on low-temperature pyrolysis includes a pyrolysis furnace, one end of which is connected to a feeding unit and the other end to a slag discharge unit. A front separator and a rear separator are respectively connected to the front and rear ends of the pyrolysis furnace. The gas outlets of the front separator and / or the rear separator are connected to a burner. The burner is connected to the pyrolysis furnace to provide heat. The burner is connected to a tail gas treatment device through a waste heat boiler.

[0008] Furthermore, the gas outlet of the front and / or rear separator is connected to the burner via a non-condensable gas pipeline. The non-condensable gas pipeline is equipped with a purification tank and a pressure stabilizing tank, which are sequentially arranged between the gas outlet of the front and / or rear separator and the burner. The burner is equipped with an air inlet, a liquefied gas inlet, and a combustible gas inlet connected to the non-condensable gas pipeline. The liquid outlet of the front and / or rear separator is connected to an oil-water separator via a liquid transfer pump.

[0009] Furthermore, the flue gas outlet of the pyrolysis furnace is connected to the burner via a regenerating fan, and the connecting pipe between the regenerating fan and the burner is connected to the exhaust gas treatment device.

[0010] Furthermore, the pyrolysis furnace includes an outer shell and a heating cylinder disposed inside the outer shell for containing medical waste, a hot air chamber is formed between the outer shell and the heating cylinder, and the burner is connected to the hot air chamber of the pyrolysis furnace.

[0011] Furthermore, the pressure stabilizing tank is connected to the pyrolysis furnace via a non-condensable gas pipeline, which is equipped with a purifier. The non-condensable gas pipeline is connected to multiple non-condensable gas branch pipes arranged circumferentially on the pyrolysis furnace, and the non-condensable gas branch pipes are interconnected. Multiple flame torches are evenly distributed on the non-condensable gas branch pipes, inserted into the hot air chamber and aimed at the heating cylinder, and the flame torches are arranged from the feed end of the pyrolysis furnace to the other end, decreasing in number.

[0012] Furthermore, the feeding unit includes a conveyor, a bag-breaking machine, a steam sterilizer, and a screw feeder connected in sequence, with the screw feeder connected to the front end of the pyrolysis furnace; the slag discharge unit includes a discharge machine, a water-cooled discharge machine, a bucket elevator, and a solid product conveyor connected in sequence to the rear end of the pyrolysis furnace.

[0013] Furthermore, the steam sterilizer includes a furnace body, which contains a sterilization chamber, a feeding chamber connected to one side of the sterilization chamber, and a discharge chamber vertically connected to the other side of the sterilization chamber. The feeding chamber has a feeding hopper at its top and a feeding mechanism inside for pushing incoming material into the sterilization chamber and the discharge chamber. The sterilization chamber is connected to a steam supply mechanism. An exhaust valve is located at the top of the sterilization chamber and is connected to a tail gas treatment device. The discharge chamber also has a vertical pushing mechanism at its top for sealing the end of the sterilization chamber and pushing material downwards into the discharge chamber. The steam supply mechanism includes a housing with a heater at the bottom and multiple vents at the top communicating with the sterilization chamber. A water supply tank is connected to one side of the housing. The sterilization chamber also has a deoxidizer inlet for adding the deoxidizer.

[0014] The pyrolysis method, including the medical waste pyrolysis system based on low-temperature pyrolysis as described in any one of the preceding claims, further includes the following steps:

[0015] S1. The bagged medical waste is broken open and then placed in a steam sterilizer. The medical waste remains in the steam sterilizer for 45–120 minutes. Afterward, an oxygen absorber is added, and the introduced steam mixes the oxygen absorber evenly with the medical waste. The waste is then compressed to an apparent density of 500–900 kg / m³. 3 Then let it age for 10–60 minutes;

[0016] S2. The medical waste processed and deoxygenated in step S1 is crushed and sent to the medical waste pyrolysis system for pyrolysis.

[0017] S3. The combustible gas after the separation of pyrolysis products is used for combustion to heat the pyrolysis furnace, the separated pyrolysis oil is upgraded to form products, and the carbon produced by pyrolysis is upgraded to form products.

[0018] Further, the deoxidizer comprises: pickled iron powder, medical waste incineration fly ash, pyrolytic carbon, and fly ash; the ratio of pickled iron powder, medical waste incineration fly ash, pyrolytic carbon, and fly ash added to the medical waste is 1:0.002~0.004:0.001~0.002:0.001~0.002:0.001~0.002; the pickled iron powder is prepared by mixing iron powder with acidic mine water, heating and stirring for 5~20 minutes, the heating temperature is 60~100℃, the effective component of the acidic mine water is H2SO4, and the pH value is 3.5~5.5.

[0019] Furthermore, step S1 also includes a method for using the steam sterilizer, which includes the following steps:

[0020] A1. After the medical waste is broken, it is put into the feed hopper of the steam sterilizer. The pushing mechanism retracts to expose the lower end of the feed hopper, causing the material to fall. The pushing mechanism extends to push the material out of the sterilization chamber. At the same time, the pushing mechanism blocks the lower end of the feed hopper, and the vertical pushing mechanism blocks the other end of the sterilization chamber, forming a sealed space in the sterilization chamber.

[0021] A2. The steam supply mechanism injects steam into the sterilization chamber to sterilize and disinfect medical waste, then shuts off the steam supply mechanism and discharges the steam through the exhaust valve;

[0022] A3. Add the deoxidizer into the sterilization chamber through the deoxidizer inlet, turn on the steam supply mechanism to mix the material and the deoxidizer evenly, and then extend the pusher mechanism to compress the material and age it;

[0023] A4. The vertical pushing mechanism retracts, and the pushing mechanism continues to extend, pushing the compressed medical waste into the discharge chamber. Then, the vertical pushing mechanism extends to push the sterilized medical waste out of the discharge chamber and into the crusher.

[0024] The beneficial effects of this invention are:

[0025] 1. The pyrolysis furnace of this invention indirectly heats medical waste in a heating cylinder under anaerobic or oxygen-deficient conditions. Utilizing continuous endothermic and exothermic reactions, the organic components in the medical waste undergo pyrolysis and thermochemical reactions, altering their original molecular structure and transforming them into substances of different phases, producing pyrolysis gas and pyrolysis char. This achieves continuous pyrolysis treatment of medical waste. Furthermore, the heat is recycled during the process, reducing costs. The system has a high overall thermal energy utilization rate, a high waste resource recovery rate, and exhaust emissions far below national standards.

[0026] 2. After medical waste is compressed, most of the oxygen is released by the deoxidizer of this invention. Fine gaps still exist between the material particles. Through the action of the deoxidizer, the residual oxygen in these gaps is further consumed, thereby ensuring an oxygen-free environment in the pyrolysis furnace, improving pyrolysis efficiency, and reducing environmental pollution. The acid-washed iron powder in the deoxidizer has high oxidation reactivity. The NaCl in the fly ash from medical waste incineration can increase the oxidation rate of the iron powder. Pyrolysis carbon and fly ash improve the permeability of the deoxidizer, further increasing the oxygen consumption rate.

[0027] 3. The pyrolysis furnace of the present invention is equipped with a flame torch on the inner wall of the outer shell and a non-condensable gas supply pipeline on the outer wall of the outer shell. Through the linkage of the non-condensable gas assisted combustion heating system and the hot air system, the temperature of the outer wall of the inner cylinder is precisely controlled. Under the efficient temperature gradient control, the rapid pyrolysis of the material inside the cylinder is effectively realized. At the same time, the quality of the pyrolysis products is improved, and the output value of the pyrolysis products is further enhanced.

[0028] 4. The high-temperature steam sterilizer of the present invention can realize continuous feeding and discharging of medical waste, which improves sterilization efficiency; the entire sterilization process does not require manual operation, and the equipment is well sealed. The sterilization steam is purified to avoid human infection and will not cause pollution to the environment. Attached Figure Description

[0029] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the medical waste pyrolysis system of the present invention;

[0031] Figure 2 This is a schematic diagram of the steam sterilizer of the present invention;

[0032] Figure 3 This is a schematic diagram of the auxiliary heating structure of the medical waste pyrolysis system of the present invention. Detailed Implementation

[0033] 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.

[0034] The medical waste pyrolysis system based on low-temperature pyrolysis described in Embodiment 1 of this invention, such as... Figure 1As shown, the medical waste pyrolysis system includes a pyrolysis furnace 8, which comprises a heating cylinder and an outer shell fitted over the heating cylinder. The outer shell is fixedly installed, and the heating cylinder is rotatably connected to the outer shell, with both ends of the heating cylinder extending out of the outer shell. The heating cylinder is used to contain medical waste, and a hot air chamber is formed between the outer shell and the heating cylinder. A heat storage ball is installed inside the heating cylinder, and a slag outlet is provided at one end of the heating cylinder. The slag outlet is equipped with a grate, which can block the heat storage ball during slag discharge to prevent it from falling out. The burner 20 has an air inlet, a liquefied petroleum gas inlet, and a combustible gas inlet at one end, and a heat supply outlet at the other end. A front separator 5 and a rear separator 9 are respectively connected to the front and rear ends of the pyrolysis furnace 8, i.e., the front and rear ends of the heating cylinder. The gas outlets of the front separator 5 and the rear separator 9 are connected to the combustible gas inlet of the burner 20 through non-condensable gas pipelines. The front separator 5 and the rear separator 9 perform gas-oil separation on the pyrolysis gas generated by combustion, and the separated combustible gas enters the combustible gas inlet of the burner 20 through the non-condensable gas pipeline. The heat outlet of burner 20 is connected to the hot air chamber of pyrolysis furnace 8 to heat the pyrolysis furnace 8, allowing the combustible gas produced from the pyrolysis of medical waste to be recycled and reused. Furthermore, liquefied petroleum gas (LPG) can be introduced through the LPG inlet 12 of burner 20. At the initial startup of the system, air and LPG are introduced, with the LPG providing heat through combustion. After the combustible gas is produced from the pyrolysis of medical waste in pyrolysis furnace 8, the amount of LPG used can be reduced. A combustion-supporting fan 21 is connected to the air inlet of burner 20 to assist combustion. In addition, the pyrolysis furnace 8 has a feeding unit connected to one end and a slag discharge unit connected to the other end. Burner 20 adopts a structure found in existing technology. The pyrolysis furnace of this invention indirectly heats medical waste to 500-600°C in a heating cylinder under anaerobic or hypoxic conditions. By utilizing continuous endothermic and exothermic reactions, the organic components in the medical waste undergo pyrolysis and thermochemical reactions, changing their original molecular structure and transforming them into substances of different phases, producing pyrolysis gas and pyrolysis char.

[0035] Furthermore, such as Figure 1 As shown, the non-condensable gas pipeline is equipped with a pump, a purification tank 10, and a pressure stabilizing tank 11. The purification tank 10 purifies the combustible gas containing impurities exiting from the gas outlets of the front separator 5 and the rear separator 9. The pressure stabilizing tank 11 is connected between the purification tank 10 and the burner 20. The purification tank 10 is connected to the pressure stabilizing tank 11 via a total pressure blower. The combustible gas after the purification tank 10 is temporarily stored in the pressure stabilizing tank 11 and then sent to the burner 20 for combustion and heating.

[0036] Furthermore, such as Figure 1 As shown, the liquid outlets of the front separator 5 and the rear separator 9 are respectively connected to an oil-water separator 7 via a pump 6. In this embodiment, the oil-water separator 7 uses a three-phase separator for three-phase separation.

[0037] Example 2 differs from Example 1 in that the pyrolysis furnace 8 has multiple flue gas outlets. These outlets are connected to the burner 20 via flue gas pipes. A regenerating fan 18 is installed on the flue gas pipes to send waste heat from the flue gas back into the pyrolysis furnace 8 for continued utilization. Simultaneously, the burner 20 is connected to a tail gas treatment device 15 via a waste heat boiler 17 to treat a portion of the flue gas. This tail gas treatment device 15 employs existing technology devices or systems. Furthermore, the flue gas pipe located between the regenerating fan 18 and the burner 20 is also connected to the tail gas treatment device 15 via a flue gas exhaust branch to purify the exhaust gas. The tail gas treatment device 15 can adopt a structure from existing technology; its specific structure will not be described in detail here.

[0038] Example 3 differs from Example 1 in that the medical waste pyrolysis system also includes an auxiliary heating structure. The pressure stabilizing tank 11 is also connected to the pyrolysis furnace 8 via a non-condensable gas pipeline. Figure 3 As shown, the auxiliary heating structure includes multiple non-condensable gas branch pipes 32 circumferentially arranged on the pyrolysis furnace 8, connected to the end of the non-condensable gas pipeline, and interconnected with each other. Multiple flame torches 33 are evenly distributed on the non-condensable gas branch pipes 32 and inserted into the hot air chamber. The ends of the flame torches 33 are all aligned with the heating cylinder, and the number of flame torches 33 in each ring gradually decreases from the feed end of the pyrolysis furnace 8 to the other end, thereby increasing the heating temperature of the heating cylinder. Furthermore, because medical waste gradually pyrolyzes after entering from the feed end, the number of flame torches 33 gradually decreases from front to back.

[0039] Example 4 differs from Example 1 in that the feeding unit includes a conveyor 1, a bag-breaking machine 2, and a steam sterilizer 3. The conveyor 1 delivers bagged medical waste to the bag-breaking machine 2, which breaks open the bags and feeds the waste into the steam sterilizer 3. The steam sterilizer 3 not only sterilizes the medical waste but also adds an oxygen absorber to compress and age it, removing oxygen from the waste. A crusher 31 is connected to the outlet of the steam sterilizer 3. The crusher breaks down the compressed medical waste into blocks within the steam sterilizer 3. The crusher 31 is connected to the front end of a pyrolysis furnace 8 via a screw feeder 4, feeding the crushed medical waste into the heating cylinder of the pyrolysis furnace 8. Both the bag-breaking machine 2 and the crusher 31 can be existing crushers.

[0040] Furthermore, the slag discharge unit includes a discharge machine 19, a water-cooled discharge machine 16, a bucket elevator 14, and a solid product conveyor 13. The discharge machine 19 is connected to the rear end of the pyrolysis furnace 8. The discharge machine 19 is connected to the water-cooled discharge machine 16 to water-cool the solid product. The water-cooled discharge machine 16 is a water-cooled screw conveyor as described in the prior art. In other embodiments, the water-cooled discharge machine 16 may also employ a water-cooling structure on the outside of the discharge machine, as described in the prior art. The water-cooled discharge machine 16 is connected to the solid product conveyor 13 via the bucket elevator 14, sending the cooled solid product into a solid product silo for temporary storage and subsequent processing.

[0041] Example 5 differs from Example 4 in that, as Figure 2 As shown, the steam sterilizer 3 includes a furnace body, which contains a horizontal feeding chamber, a sterilization chamber 22, and a vertical discharge chamber 24. The horizontal feeding chamber communicates with the vertical discharge chamber 24 through the sterilization chamber 22. The horizontal feeding chamber is connected to one end of the sterilization chamber 22, and the vertical discharge chamber 24 is vertically connected to the other end of the sterilization chamber 22. A steam supply mechanism is connected to the bottom of the sterilization chamber 22, and an exhaust outlet with an exhaust valve 27 is connected to the top. In another embodiment, the exhaust valve 27 is connected to the aforementioned exhaust gas treatment device 15. A feeding hopper 23 is located at the top of the feeding chamber near the sterilization chamber 22. A feeding mechanism 30 is provided inside the feeding chamber to push the material entering the furnace body from the feeding hopper 23 into the sterilization chamber 22. After being pushed in, the feeding mechanism 30 simultaneously seals the lower port of the feeding hopper 23. The material is sterilized by high-temperature steam in the sterilization chamber 22. The feeding mechanism 30 can also push the material into the discharge chamber 24. The top of the discharge chamber 24 is also equipped with a vertical pushing mechanism 29 for pushing the material into the discharge chamber 24 downwards. The pushing mechanism and the vertical pushing mechanism 29 can be hydraulic cylinders, pneumatic cylinders, or electric push rods, and the pneumatic extension end is made of a high-temperature resistant material. The working ends of the pushing mechanism 30 and the vertical pushing mechanism 29 are both provided with a certain thickness. The thickness of the working end of the pushing mechanism 30 can seal the lower port of the feed hopper 23; the thickness of the working end of the vertical pushing mechanism 29 can seal the end of the sterilization chamber 22 away from the pushing mechanism 30, that is, seal the intersection of the sterilization chamber 22 and the discharge chamber 24, so that a sealed space can be formed in the sterilization chamber 22, which is convenient for high-temperature steam sterilization.

[0042] The feeding mechanism 30, due to its long stroke, can employ a double-stroke hydraulic cylinder or a double-stroke pneumatic cylinder. Alternatively, it can use two hydraulic cylinders, pneumatic cylinders, or electric push rods connected in series, with the telescopic end of the latter facing the sterilization chamber 22 and its fixed end fixed to the telescopic end of the former. The fixed end of the former is fixed inside the feeding chamber at the end furthest from the sterilization chamber. The vertical pushing mechanism 29 can also adopt the above structure.

[0043] Furthermore, the steam supply mechanism includes a box 25 disposed on the lower side of the sterilization chamber 22. The bottom of the box 25 is provided with a heater, and the top of the box 25 is provided with multiple air holes between it and the sterilization chamber 22 so that the box 25 communicates with the sterilization chamber 22, thereby allowing steam to enter the sterilization chamber. A water supply tank 26 is connected to one side of the box 25 through a water supply pipe.

[0044] In this embodiment, the lower port of the feeding hopper 23 is sealed by the pushing mechanism 30, and the side of the working end of the vertical pushing mechanism 29 blocks the other end of the sterilization chamber 22, keeping the sterilization chamber 22 in a sealed state. The steam supplied to the sterilization chamber 22 by the steam supply mechanism can increase the pressure inside the sterilization chamber 22. A pressure of 0.2~0.3 MPa allows the steam temperature inside the sterilization chamber 22 to be between 120~140℃, resulting in better sterilization of the medical waste inside the sterilization chamber. The exhaust valve 27 can be mechanically controlled for venting; alternatively, it can be an automatic exhaust valve that automatically vents and reduces pressure when the pressure exceeds 0.3 MPa.

[0045] Example 6 differs from Example 5 in that the sterilization chamber 22 is further provided with an oxygen absorber inlet 28 for adding the aforementioned oxygen absorber.

[0046] Example 7, pyrolysis method, including the above-mentioned medical waste pyrolysis system based on low-temperature pyrolysis, further includes the following steps:

[0047] S1. The bagged medical waste is broken open and then placed into a steam sterilizer 3 for high-temperature steam sterilization. The medical waste remains in the steam sterilizer 3 for 45–120 minutes. Afterward, an oxygen absorber is added, and the blown steam mixes the oxygen absorber and medical waste evenly. The medical waste is then compressed to an apparent density of 500–900 kg / m³ by the feeding mechanism and vertical pushing mechanism within the steam sterilizer 3. 3 Then let it age for 10–60 minutes;

[0048] S2. The compacted medical waste processed and deoxygenated in step S1 is crushed and then sent into the medical waste pyrolysis system for pyrolysis.

[0049] S3. The combustible gas after the separation of pyrolysis products is used for combustion to heat the pyrolysis furnace, the separated pyrolysis oil is upgraded to form products, and the carbon produced by pyrolysis is upgraded to form products.

[0050] Furthermore, the deoxidizer comprises: pickled iron powder, medical waste incineration fly ash, pyrolytic carbon, and fly ash; the ratio of pickled iron powder, medical waste incineration fly ash, pyrolytic carbon, and fly ash added to the medical waste is 1:0.002~0.004:0.001~0.002:0.001~0.002:0.001~0.002, that is, 1 part of medical waste is mixed with 0.002~0.004 parts of pickled iron powder, 0.001~0.002 parts of medical waste incineration fly ash, 0.001~0.002 parts of pyrolytic carbon, and 0.001~0.002 parts of fly ash.

[0051] The method for preparing the pickled iron powder is as follows: iron powder is mixed with acidic mine water, heated and stirred for 5 to 20 minutes, the heating temperature is 60 to 100°C, the effective component of the acidic mine water is H2SO4, and the pH value is 3.5 to 5.5.

[0052] Example 8 differs from Example 7 in that step S1 further includes a method for using the steam sterilizer 3, which includes the following steps:

[0053] A1. After the medical waste is broken, it is put into the feed hopper 23 of the steam sterilizer 3. The pushing mechanism 30 retracts, exposing the lower port of the feed hopper 23 so that the medical waste material in the feed hopper 23 enters the pushing chamber. Then the pushing mechanism 30 extends to push the material into the sterilization chamber 22 while blocking the lower port of the feed hopper 23. At the same time, the vertical pushing mechanism 29 works so that the side of its working end blocks the other end of the sterilization chamber 22, that is, the end near the discharge chamber 24, forming a closed space in the sterilization chamber 22.

[0054] A2. The steam supply mechanism injects steam into the sterilization chamber 22 to sterilize and disinfect the medical waste. The medical waste stays in the steam sterilizer 3 for 45 to 120 minutes. After that, the exhaust valve 27 is opened to discharge the steam. The discharged steam enters the exhaust gas treatment device for treatment.

[0055] A3. The deoxidizer is introduced into the sterilization chamber 22 through the deoxidizer inlet 28. The steam supply mechanism is turned on to ensure that the material and the deoxidizer are mixed evenly. During the process, because medical waste is relatively soft, it is in a turbulent sulfurized state when steam is blown in from the bottom, which facilitates even mixing with the deoxidizer. Then, the working end of the pushing mechanism 30 extends to the working end of the vertical pushing mechanism 29 to compress and age the medical waste. The aging time is 10-60 minutes. The squeezed gas is discharged through the exhaust valve 27, removing oxygen from the medical waste through compression. The deoxidizer further achieves the purpose of deoxygenation.

[0056] A4. The vertical pushing mechanism 29 retracts, and the working end of the pushing mechanism 30 extends, pushing the sterilized and compressed medical waste into the discharge chamber 24. Then, the vertical pushing mechanism 29 extends, pushing the sterilized medical waste out of the discharge chamber 24 and into the crusher 31.

[0057] The aforementioned deoxygenation steps allow medical waste to be indirectly heated in a heating cylinder under anaerobic conditions after entering the pyrolysis furnace. Through continuous endothermic and exothermic reactions, the organic components in the medical waste undergo pyrolysis and thermochemical reactions, changing their original molecular structure and transforming them into substances of different phases, producing pyrolysis gas and pyrolysis char, thus achieving continuous pyrolysis treatment of medical waste.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A medical waste pyrolysis system based on low temperature pyrolysis, characterized by: The pyrolysis furnace (8) is connected with a feeding unit at one end and a slagging unit at the other end, and the front and rear ends of the pyrolysis furnace (8) are connected with a front distributor (5) and a rear distributor (9) respectively, and the gas outlet of the front distributor (5) and / or the rear distributor (9) is connected with a burner (20); the burner (20) is connected with the pyrolysis furnace (8) for providing heat; the burner (20) is connected with a tail gas treatment device (15) through a waste heat boiler (17); the pyrolysis furnace (8) comprises an outer shell and a heating cylinder arranged in the outer shell for containing medical waste, and a hot air cavity is formed between the outer shell and the heating cylinder, and the burner (20) is connected with the hot air cavity of the pyrolysis furnace (8); the gas outlet of the front distributor (5) and the rear distributor (9) is connected with the burner (20) through a non-condensable gas pipeline, and a purification tank (10) and a pressure stabilizing tank (11) are arranged on the non-condensable gas pipeline; the pressure stabilizing tank (11) is also connected to the pyrolysis furnace (8) through a non-condensable gas pipeline; a plurality of non-condensable gas branch pipes (32) are arranged on the pyrolysis furnace (8) in a circumferential direction, and the non-condensable gas branch pipes (32) are communicated with each other; a plurality of flame lances (33) are uniformly arranged on the non-condensable gas branch pipes (32) and inserted into the hot air cavity and aligned with the heating cylinder, and the flame lances (33) are arranged from more to less from the feeding end to the other end of the pyrolysis furnace (8); the feeding unit comprises a conveyor (1), a bag breaker (2), a steam sterilization furnace (3), a crusher (31) and a screw feeder (4) connected in sequence, and the screw feeder (4) is connected with the front end of the pyrolysis furnace (8); the slagging unit comprises a discharging machine (19), a water-cooled discharging machine (16), a bucket elevator (14) and a solid product conveyor (13) connected in sequence at the rear end of the pyrolysis furnace (8); the steam sterilization furnace comprises a furnace body, and a sterilization cavity (22) is arranged in the furnace body; a deoxidizer adding port (28) is further arranged on the sterilization cavity (22) for adding the deoxidizer; the composition of the deoxidizer comprises: pickling iron powder, medical waste incineration fly ash, pyrolysis carbon and fly ash; the proportions of the pickling iron powder, the medical waste incineration fly ash, the pyrolysis carbon and the fly ash added in the medical waste are 1:0.002-0.004:0.001-0.002:0.001-0.002:0.001-0.002; the preparation method of the pickling iron powder is: mixing iron powder with acid mine water, heating and stirring for 5-20 min, the heating temperature is 60-100℃, the effective component in the acid mine water is H2SO4, and the PH value is 3.5-5.

5.

2. The low temperature pyrolysis based medical waste pyrolysis system of claim 1, wherein: The purification tank (10) and the pressure stabilizing tank (11) are arranged in sequence between the gas outlet of the front distributor (5) and / or the rear distributor (9) and the burner (20); the burner (20) is provided with an air inlet, a liquefied gas inlet (12) and a combustible gas inlet connected with the non-condensable gas pipeline; the liquid outlet of the front distributor (5) and / or the rear distributor (9) is connected with an oil-water separator (7) through a liquid feeding pump (6).

3. The low temperature pyrolysis based medical waste pyrolysis system of claim 2, wherein: The flue gas outlet of the pyrolysis furnace (8) is connected with the burner (20) and the tail gas treatment device (15) through the regenerative blower (18) respectively.

4. The low temperature pyrolysis based medical waste pyrolysis system of claim 3, wherein: The furnace body is provided with a pushing chamber communicated with one side of the sterilization chamber (22) and a dropping chamber (24) vertically connected with the other side of the sterilization chamber (22), the top of the pushing chamber is provided with a feeding hopper (23), and a pushing mechanism (30) is arranged in the pushing chamber for pushing the entering material into the sterilization chamber (22) and the dropping chamber (24); the sterilization chamber (22) is connected with a steam supply mechanism; the top of the sterilization chamber (22) is provided with an exhaust valve (27) connected with the tail gas treatment device (15); the top of the dropping chamber (24) is provided with a vertical pushing mechanism (29) for closing the end of the sterilization chamber (22) and pushing the material entering the dropping chamber (24) downward; the steam supply mechanism comprises a box body (25), the bottom of the box body (25) is provided with a heater, the top of the box body (25) is communicated with the sterilization chamber (22) through a plurality of air holes, and one side of the box body (25) is connected with a water supplement tank (26).

5. Pyrolysis process, characterized in that, The medical waste pyrolysis system based on low-temperature pyrolysis comprises the medical waste pyrolysis system based on low-temperature pyrolysis according to any one of claims 1-4, and further comprises the following steps: S1. The bagged medical waste is broken and put into the steam sterilization furnace (3). The medical waste stays in the steam sterilization furnace (3) for 45-120 min, and then the deoxidizing agent is added. The steam blowing makes the deoxidizing agent and the medical waste mix uniformly, and is extruded to the apparent density of 500-900 kg / m 3 , and then aged for 10-60 min. S2. crushing the medical waste after being treated and extrusion-deoxidized in step S1 and feeding the medical waste into the medical waste pyrolysis system for pyrolysis; S3. using the combustible gas separated from the pyrolysis products to provide heat for the pyrolysis furnace, using the pyrolysis oil separated from the pyrolysis products to form products, and using the carbon produced by pyrolysis to form products.

6. The pyrolysis method of claim 5, wherein, The use method of the steam sterilization furnace (3) in step S1 comprises the following steps: S11. feeding the medical waste after bag breaking into the feeding hopper (23) of the steam sterilization furnace (3), retracting the pushing mechanism (30) to expose the lower end of the feeding hopper (23) to make the material fall, extending the pushing mechanism (30) to push the material out of the sterilization chamber (22), meanwhile, the pushing mechanism (30) blocks the lower end of the feeding hopper (23), and the vertical pushing mechanism (29) blocks the other end of the sterilization chamber (22), thereby forming a closed space in the sterilization chamber (22); S12. injecting steam into the sterilization chamber (22) by the steam supply mechanism to sterilize and disinfect the medical waste, then closing the steam supply mechanism and discharging the steam through the exhaust valve (27); S13. feeding the deoxidizer into the sterilization chamber (22) through the deoxidizer feeding port (28), opening the steam supply mechanism to mix the material with the deoxidizer uniformly, then closing the steam supply mechanism, extending the pushing mechanism (30) to compress the material and aging; S14. retracting the vertical pushing mechanism (29) and continuing to extend the pushing mechanism (30) to push the compressed medical waste into the dropping chamber (24), then extending the vertical pushing mechanism (29) to push the sterilized medical waste out of the dropping chamber (24) into the crusher (31).

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