A high-temperature pyrolysis and multi-oxygen incineration treatment process and system for medical waste

Abstract

The present invention proposes a high-temperature pyrolysis and multi-oxygen incineration treatment process and system for medical waste. The process freezes and crushes the medical waste, and then screens it. During the screening, inorganic substances are separated and discharged after sterilization; the remaining organic substances are reverse-burned and gasified for multi-oxygen incineration; the generated gasification gas is firstly used for waste heat utilization, and the low-pressure steam generated by the waste heat utilization is used for medical institutions, and the low-temperature flue gas generated is used for reflux to adjust the oxygen-rich concentration of reverse-burning gasification and multi-oxygen incineration; the solid products of reverse-burning gasification and multi-oxygen incineration are treated with ash; the oxygen during reverse-burning gasification and multi-oxygen incineration is supplied by the surplus oxygen in the liquid oxygen production link. The process system of the present invention has the characteristics of distributed miniaturization, rapid start and stop, and can be used at any time, and can be shut down at any time. It also rationally utilizes the surplus cold in the hospital's own liquid oxygen gasification, rationally utilizes energy, solves the oxygen demand for multi-oxygen incineration, and forms a comprehensive medical institution waste distributed comprehensive utilization system.

Description

Technical Field

[0001] The invention relates to medical waste treatment, and in particular to a high-temperature pyrolysis method for treating medical waste. Background Art

[0002] In the operation of medical institutions, a large amount of medical waste is generated, forming solid waste that may contain bacteria, viruses, and pollutants. Governments of various countries attach great importance to the classification, storage, transportation, and disposal management of medical waste.

[0003] Medical waste mainly refers to the garbage and waste materials generated during the entire medical process, mainly composed of plastics, waste paper, kitchen waste, wood and bamboo, fiber, leather, rubber, surgical resections, glassware, etc. Most of these wastes are organic hydrocarbons, which can be completely burned into ashes under certain temperature and sufficient oxygen conditions. After incineration, medical waste can not only completely kill bacteria and viruses, but also convert most organic matter into inorganic matter, and also greatly reduce the volume of waste by 85% to 95%, making the waste difficult to identify. This greatly reduces the cost and land occupation of the final sealed landfill, eliminates people's aversion to medical waste, and the technology is mature. At present, the most commonly used method for the treatment of medical waste is incineration.

[0004] However, the biggest problem with the incineration method is that hospitals in cities are scattered and produce less solid waste, which is far from centralized incineration plants. The daily collection, transportation, and storage process consumes a lot of manpower and material resources, and there is a risk of environmental pollution. At present, the management requires hospitals to pay for the treatment, and their enthusiasm is not high.

[0005] At the same time, Article 17 of my country's "Regulations on Medical Waste Management" also clearly stipulates that the temporary storage time of medical waste shall not exceed 2 days. In fact, in the process of centralized disposal, due to various reasons, "medical waste left in the air for a long time or stored for too long is extremely harmful to the environment and human body, and may cause infectious diseases, damage human health, and pollute soil, water quality and atmosphere." - This is a factor that cannot be implemented in actual disposal.

[0006] Therefore, there is an urgent need for a solution for timely incineration and efficient treatment of hazardous waste on site. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a high-temperature pyrolysis and multi-oxygen incineration treatment process and system for medical waste, so as to solve the current problems that medical solid waste cannot be treated on-site, the economy is not high, and the medical waste cannot be treated in time due to excessive storage time. The process system of the present invention is designed in a distributed and miniaturized manner to address the shortcomings of a large number of medical institutions, a high degree of centralized disposal, and omissions in the collection and storage and transportation processes. It has the simplicity of rapid start and stop, and can be used at any time.

[0008] To achieve the above purpose, the present invention intends to adopt the following technical means:

[0009] A high-temperature pyrolysis and multi-oxygen incineration treatment process for medical waste, in which the medical waste is first frozen and then crushed, and then screened, and inorganic substances in the medical waste are separated during screening, and discharged after sterilization; the remaining organic substances are back-burned, gasified and incinerated by multi-oxygen;

[0010] The gasification gas produced by the reverse-burning gasification and oxy-fuel incineration is firstly utilized as waste heat. The low-pressure steam generated by the waste heat utilization is provided to medical institutions, and the low-temperature flue gas generated is used for reflux to adjust the oxygen-rich concentration of the reverse-burning gasification and oxy-fuel incineration; the solid products of the reverse-burning gasification and oxy-fuel incineration are treated as ash; the oxygen during the reverse-burning gasification and oxy-fuel incineration is supplied by the surplus oxygen in the liquid oxygen production link.

[0011] Preferably, the cold source for freezing medical waste comes from the surplus cold in the hospital's liquid oxygen production process.

[0012] Preferably, the incineration occurs at 850-1000°C by adjusting and controlling the oxygen enrichment concentration.

[0013] The present invention also provides a high-temperature pyrolysis and multi-oxygen incineration treatment system for medical waste, including a solid waste freezing storage tank, a grading and screening device, a back-burning gasification multi-oxygen incinerator, and a waste heat utilization device;

[0014] Medical waste is first frozen in a solid waste freezing storage tank and then crushed, and then screened by a grading and screening device. During the screening, inorganic substances in the medical waste are separated and discharged after sterilization; the remaining organic substances are incinerated in a reverse-burning gasification multi-oxygen incinerator;

[0015] The gasification gas produced by incineration is firstly used by the waste heat utilization equipment for waste heat utilization. The low-pressure steam produced by the waste heat utilization is used again by medical institutions, and the low-temperature flue gas produced is used for reflux to adjust the oxygen-rich concentration in the reverse-burning gasification multi-oxygen incinerator; the solid products of incineration are treated as ash;

[0016] The oxygen during incineration is supplied by the surplus oxygen in the liquid oxygen production process.

[0017] Furthermore, it also includes disinfection equipment. The medical waste is first frozen in a solid waste freezing storage box and then crushed. After crushing, it is disinfected by disinfection equipment, and then screened by grading and screening equipment. During the screening, inorganic substances in the medical waste are separated and discharged after disinfection by the disinfection equipment.

[0018] Furthermore, it also includes flue gas purification equipment. The low-temperature flue gas generated by waste heat utilization is used for reflux adjustment of the oxygen-rich concentration in the reverse-burning gasification multi-oxygen incinerator after passing through the flue gas purification equipment.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] The high-temperature pyrolysis and multi-oxygen incineration treatment process of medical waste of the present invention adopts a high-temperature pyrolysis method and is a new medical waste treatment process method. It has the advantages of miniaturized system integration, can recycle the surplus cold energy in the hospital's oxygen production, and treat hazardous wastes through low-temperature treatment, back-burning gasification, multi-oxygen re-combustion, and high-temperature flue gas recycling treatment processes, so that the system process is simplified, the flue gas volume is extremely small, and an integrated skid-mounted integrated device can be formed, which is dispersedly arranged in large and medium-sized hospitals in the city, implements on-site treatment, and has the advantages of treating medical waste from surrounding small medical units. At the same time, it achieves the purpose of low-temperature storage, rapid disposal, and reasonable use of heat energy. Specifically:

[0021] 1. The present invention adopts a system integration design, and can process medical waste at a scale of 100-1000kg / h. It can realize skid-mounted, standardized, serialized design, and container-type production.

[0022] 2. The process of the present invention targets the medical waste output of medium-sized and above comprehensive hospitals (1,000 sheets), and covers the medical waste output of small medical institutions within a certain distance (e.g., within 10 km) in the surrounding area. The waste is collected and processed on the same day, which can effectively implement the storage time limit of more than 2 days stipulated in the "Medical Waste Management Regulations", reduce the node omission factors in the intermediate handover and transportation links, avoid the risk of pollutant leakage, and reduce the collection and storage costs;

[0023] 3. The high-temperature pyrolysis and oxy-incineration treatment method for medical waste of the present invention can significantly reduce the cost of treating medical waste, and hospitals can manage independently with clear responsibilities; it reduces the transfer links of medical waste, saves medical waste treatment costs, and improves the enthusiasm of hospitals.

[0024] 4. The high-temperature pyrolysis and multi-oxygen incineration treatment method of medical waste of the present invention is a zero-pollution treatment process for medical waste, achieving the environmental protection goal of fully utilizing organic matter in medical waste as a resource. It greatly reduces the generation of atmospheric pollutants such as dioxins and NOx, increases the calorific value of pyrolysis gas, and reduces flue gas emissions.

[0025] 5. The treatment method of the present invention adds flue gas recirculation to the oxygen-rich atmosphere to reduce and reasonably control the oxygen concentration, thereby reducing the flame temperature of the combustion of pyrolysis gas and pure oxygen, and at the same time uses the method of changing the fluid form of pyrolysis gas and oxygen to protect the pyrolysis gas burner from overheating and burning, so that the pyrolysis gas burner has a longer service life under high temperature and oxygen-rich conditions.

[0026] 6. The present invention uses flue gas recirculation, which greatly reduces the amount of N2 involved in the incineration process, greatly reduces the amount of flue gas discharged, makes flue gas purification easier, and at the same time, the system thermal efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process system flow chart of the present invention.

[0028] The solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0029] The medical waste mentioned in the present invention mainly refers to the garbage and waste materials generated during the entire medical process. According to the current relevant national regulations, the "Medical Waste Classification Catalog" divides medical waste into 5 categories:

[0030] 1) Infectious waste: refers to medical waste that carries pathogenic microorganisms and has the risk of causing the spread of infectious diseases, including items contaminated by patients' blood, body fluids, and excrement, and garbage generated by patients with infectious diseases;

[0031] 2) Pathological waste: refers to human waste and animal carcasses generated during the diagnosis and treatment process, including discarded human tissue generated during surgery, discarded human tissue after pathological sections, pathological wax blocks, etc.;

[0032] 3) Injurious waste: refers to discarded medical sharps that can stab or cut the human body, including medical needles, scalpels, surgical knives, glass test tubes, etc.;

[0033] 4) Pharmaceutical waste: refers to discarded drugs that are expired, obsolete, deteriorated or contaminated, including discarded general drugs, discarded cytotoxic drugs and genotoxic drugs, etc.;

[0034] 5) Chemical waste: refers to discarded chemicals that are toxic, corrosive, flammable and explosive, such as discarded chemical reagents, chemical disinfectants, mercury sphygmomanometers, mercury thermometers, etc.

[0035] It should be noted that used disposable plastic infusion bottles do not belong to medical waste, and the medical waste described in this patent does not include such recyclable medical waste.

[0036] The reverse-burning gasification and multi-oxygen incineration described in the present invention, wherein reverse-burning is a combustion method in which fuel is added from the bottom, the high-temperature zone is generally in the middle and upper part of the furnace cavity, and, unlike a direct-burning furnace, not all of the generated flue gas is extracted. In the present invention, part of the low-temperature flue gas is sent back to the reverse-burning gasification and multi-oxygen incineration furnace for reflux regulation, and at the same time, a part of the gas is prompted to undergo a second gasification and combustion.

[0037] In the reverse combustion gasification multi-oxygen incineration link of the present invention, multi-oxygen means that the mass percentage of oxygen in the high-concentration oxygen is 50-100%, and the mass ratio of hazardous solid waste to high-concentration oxygen depends on the incineration situation and the surplus oxygen in the liquid oxygen production link of the hospital.

[0038] In addition, in the high-temperature pyrolysis and oxy-incineration treatment of medical waste described in the present invention, high-temperature pyrolysis means that pyrolysis occurs at 850-1000°C, which has environmental advantages.

[0039] The oxygen in the reverse combustion gasification multi-oxygen incineration of the present invention is supplied by the surplus oxygen in the liquid oxygen production link, wherein the "liquid oxygen production link" is operated by the hospital. Since the hospital is a medical institution, it needs to be equipped with a liquid oxygen tank or a liquid oxygen station to store oxygen for backup. Usually, oxygen is produced by an oxygen generator and stored in a liquid oxygen tank or a liquid oxygen station. The scheme of the present invention can make full use of the oxygen in the liquid oxygen tank of the hospital.

[0040] The high-temperature pyrolysis and multi-oxygen incineration treatment method of medical waste of the present invention is a zero-pollution treatment process of medical waste, which realizes the environmental protection goal of full resource utilization of organic matter in medical waste, greatly reduces the generation of atmospheric pollutants such as dioxins and NOx, increases the calorific value of pyrolysis gas, and reduces smoke emissions.

[0041] The "reverse-burning gasification multi-oxygen incinerator", "waste heat utilization equipment" and the low-pressure steam generated by "re-use by medical institutions" provided in the following embodiments respectively refer to: the reverse-burning gasification multi-oxygen incinerator utilizes the currently common coal-fired reverse-burning gasification furnace, and controls the combustion temperature and oxygen content to meet the requirements of this process. "Waste heat utilization equipment" may include a waste heat boiler, which generates low-pressure steam that is first used for high-temperature sterilization of screened metal and glass debris, and the surplus steam can be used for hospital disinfection, etc. "Re-use by medical institutions" refers to use in hospitals where high and low temperature steam is needed, such as hospital disinfection.

[0042] The inventor of this application has conducted a preliminary investigation:

[0043] The statistical bulletin of health and family planning development in a medium-sized city (Xi'an) with a population of 8 million shows that at the end of 2015, the total number of medical and health institutions in the city was 5,802, including 295 hospitals, 5,245 primary medical and health institutions, 238 professional public health institutions, and 24 others. According to the investigation, hospitals, which only account for about 5% of the total number of medical and health institutions in the city, have become the institutions with the largest output of medical waste in the city.

[0044] According to the city's central hospital (a medium-sized hospital with more than 1,000 beds, which is only one-third of the beds in the city's large hospitals), "the hospital produces about 25 to 30 barrels of medical waste every day, each barrel weighing about 15 kilograms, totaling about 375 kilograms to 450 kilograms." In other words, the daily output of medical waste from the city's large hospitals is as high as more than 1.3 tons.

[0045] Compared with large medical and health institutions, the output of primary medical and health institutions is negligible. The latest medical waste disposal delivery and handover form of a clinic in the district shows that the total amount of medical waste on December 22, 2016 was 2.5kg, which can easily flow into domestic waste.

[0046] According to data from 2020, there are 311 hospitals within the jurisdiction of Xi'an, including 24 Grade A hospitals with 55,789 beds. The estimated medical waste production is nearly 30t / d. Currently, there is only one centralized treatment plant, and its operating capacity is insufficient.

[0047] The present invention is a new process technology solution developed after market and technical research path investigation. Its basic principle is fully mature and feasible. The output of medical waste is based on the data of the current actual medium-sized comprehensive hospital (1,000 beds). The cold box type medical waste storage box is designed by using the refrigeration capacity of medical liquid oxygen vaporization. It has outstanding characteristics, is theoretically feasible, and is energy-saving and environmentally friendly. The design idea of ​​the reverse burning pyrolysis gasification device draws on the traditional reverse burning coal-fired boiler. The multi-oxygen combustion has the characteristics of high combustion temperature and small flue gas volume. The concept of using flue gas reflux and regulating the combustion temperature with flow is novel and reasonable. It utilizes the cold energy in the process of liquid oxygen vaporization in the hospital, and puts the medical waste generated on the day into the freezer for low-temperature freezing on the spot, reducing the pollution source and the opportunity for the leakage of pathogens. At the same time, it avoids the common centralized treatment due to the long time of solid waste collection, transportation, storage, centralized incineration, multiple interfaces, and the possible long exposure time of medical waste, leakage of pollutants, and high disposal costs. On the one hand, the surplus cold source generated when the existing liquid oxygen in the hospital is vaporized is utilized. On the other hand, pure oxygen is used for high-temperature combustion during incineration. The combustion temperature is controllable, the incineration is thorough, dioxin generation is eliminated, and the flue gas volume is extremely small, thereby reducing the cost of flue gas purification. The system process of the present invention has a high degree of integration, and the medical waste storage box can be equipped with refrigeration function and mechanical crushing function, and heavy metal and glass debris are screened out. The remaining organic waste is sterilized by ozone in a closed manner and then enters the polyoxygen incinerator. The incinerator has the functions of flue gas recycling and waste heat recovery. The low-pressure steam generated is first used for high-temperature sterilization of the screened metal and glass debris. The surplus steam can be used for hospital disinfection, etc., and the waste heat is fully utilized. A part of the flue gas after waste heat utilization is recycled for combustion, and a part is purified by adsorption before being discharged in compliance with the emission standards. This process method has high system integration, complete functions, high degree of automation control, and can be designed as a series of skid-mounted products with a processing capacity of 100-1000kg / h. It can also be composed of 2-4 unit modules. It is very convenient to install and apply on site, and can realize the system application of a single system with a processing capacity of less than 1t / h. For large medical structures, 2-3 sets of processing systems can be used. This process method is a supplementary application to the current centralized incineration treatment of medical waste (solid waste).

[0048] Embodiment 1:

[0049] According to the above process, this embodiment provides a high-temperature pyrolysis and multi-oxygen incineration treatment system for medical waste. The system uses the residual energy of liquid oxygen refrigeration commonly used in hospitals to make the medical waste storage box into a storage box with a freezing function (below -10°C). On the one hand, it reduces the activity of pathogens, and on the other hand, it is collected in a very timely manner, does not involve transportation and storage links, and reduces costs; by designing a crushing mechanism at the bottom of the garbage storage box, the frozen medical waste is crushed and sterilized with ozone; after sterilization, it is automatically screened to separate a very small amount of metal, glass and other debris, and then further sterilized with high-temperature steam before being discharged from the system. External disposal; The crushed and ozone-sterilized medical waste is transported to the reverse-burning gasification multi-oxygen incinerator in a closed manner for reverse-burning gasification, and the gasification gas is then incinerated at high temperature through oxygen-enriched gas. The oxygen-enriched concentration can be adjusted through flue gas recirculation to control the combustion temperature to ensure combustion at 850-1000°C. The combustion is fully and cleanly carried out by adopting oxygen-enriched combustion, with very little flue gas volume and controllable and adjustable combustion temperature. The waste heat of the flue gas is utilized to produce low-pressure steam for ozone preparation, hospital disinfection and other purposes, realizing energy recovery. The low-temperature flue gas reflux after waste heat utilization is used to adjust the combustion oxygen concentration and control the combustion temperature.

[0050] In particular, the cold source for freezing medical waste comes from the surplus cold in the hospital's liquid oxygen production process. The advantage of this is that it rationally utilizes the surplus cold in the hospital's liquid oxygen production process, and can design refrigerated medical waste storage tanks. The small amount of liquid waste that may exist can be solidified to avoid leakage and deterioration, reduce the activity of pollutants, and reduce the risk of pollution.

[0051] Solid waste freezing storage box with crushing function makes rational use of the physical properties of medical waste in the frozen state. After solidification, it is easy to be mechanically crushed, which is convenient for subsequent treatment. The small pieces of medical waste after crushing can be sterilized by conventional ozone, ultraviolet rays, etc.; the small pieces of medical waste after crushing can be conveniently sent to the next link for treatment by closed conveying machinery, which improves the feasibility of implementation.

[0052] The method of high-temperature pyrolysis and multi-oxygen incineration treatment of medical waste can be designed with reference to the design concept of coal-fired reverse burning furnace, which increases the feasibility. By adjusting and controlling the oxygen enrichment concentration, the incineration is carried out at 850-1000℃ with multi-oxygen incineration. The flue gas contains very little N2, which reduces the generation of dioxins and has environmental advantages. The reverse burning uses hot flue gas to pyrolyze the waste, which belongs to anaerobic and carbon-rich pyrolysis. The pyrolysis gas has a high combustible component and high calorific value, making further multi-oxygen incineration of the pyrolysis gas easier to achieve and control. At the same time, the flue gas is used for waste heat utilization, the flue gas volume is small, the flue gas temperature is high, and it is easy to realize miniaturized waste heat utilization, and the waste heat steam can be used by the hospital. The flue gas volume is small, and part of the flue gas is backfired to adjust the multi-oxygen concentration and control the incineration at 850-1000℃, while achieving further combustion of the flue gas and more thorough disinfection of pathogens.

[0053] Effect demonstration:

[0054] The system of the present invention can be skid-mounted and designed as a series of skid-mounted products with a processing capacity of 100-1000kg / h, or it can be composed of 2-4 unit modules, which can realize the system application of a single system with a processing capacity of less than 3t / h. For large medical structures, 2-3 processing systems can be used. This process method is a supplementary application to the current centralized incineration treatment of medical waste (solid waste).

Claims

1. A high-temperature pyrolysis and multi-oxygen incineration treatment device for medical waste, characterized in that: Including solid waste freezing storage tanks, grading and screening equipment, reverse burning gasification multi-oxygen incinerators and waste heat utilization equipment; The medical waste storage box is made into a solid waste freezing storage box with a freezing function. The lower part of the solid waste freezing storage box is designed with a crushing mechanism. The medical waste is first frozen in the solid waste freezing storage box and then crushed, and then screened by a grading and screening device. During the screening, inorganic substances in the medical waste are separated and discharged after sterilization; the remaining organic substances are incinerated in a reverse-burning gasification multi-oxygen incinerator; The gasification gas produced by incineration is firstly used by the waste heat utilization equipment for waste heat utilization. The low-pressure steam produced by the waste heat utilization is used again by medical institutions, and the low-temperature flue gas produced is used for reflux to adjust the oxygen-rich concentration in the reverse-burning gasification multi-oxygen incinerator; the solid products of incineration are treated as ash; The oxygen used for incineration is supplied by the surplus oxygen in the liquid oxygen production process, and the cold source for freezing medical waste comes from the surplus cold in the liquid oxygen production process of the hospital.

2. The high-temperature pyrolysis and multi-oxygen incineration treatment device for medical waste according to claim 1, characterized in that: The system also includes disinfection equipment. The medical waste is first frozen in a solid waste freezing storage box and then crushed. After crushing, it is disinfected by disinfection equipment and then screened by grading and screening equipment. During the screening, the inorganic substances in the medical waste are separated and discharged after disinfection by the disinfection equipment.

3. The high-temperature pyrolysis and multi-oxygen incineration treatment device for medical waste according to claim 1, characterized in that: The system also includes a flue gas purification device. The low-temperature flue gas generated by waste heat utilization is used for reflux adjustment of the oxygen-rich concentration in the reverse-burning gasification multi-oxygen incinerator after passing through the flue gas purification device.

4. A high-temperature pyrolysis and multi-oxygen incineration process for medical waste, characterized in that: A medical waste high-temperature pyrolysis and multi-oxygen incineration treatment device as described in any one of claims 1 to 3 is used.

5. The high-temperature pyrolysis and multi-oxygen incineration process for medical waste according to claim 4, characterized in that: By adjusting and controlling the oxygen enrichment concentration, incineration occurs at 850-1000°C.

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