CN106244242B

CN106244242B - Novel medical waste plasma gasification treatment system

Info

Publication number: CN106244242B
Application number: CN201610750754.8A
Authority: CN
Inventors: 肖燕; 李军; 陈竹; 李要建
Original assignee: Jiangsu Tianying Environmental Protection Energy Equipment Co Ltd
Current assignee: Jiangsu Tianying Environmental Protection Energy Equipment Co Ltd
Priority date: 2016-08-30
Filing date: 2016-08-30
Publication date: 2021-07-30
Anticipated expiration: 2036-08-30
Also published as: CN106244242A

Abstract

A novel medical waste plasma gasification treatment system relates to the field of environmental protection equipment. The device comprises a plasma furnace, wherein a synthesis gas outlet of the plasma furnace is sequentially connected with a synthesis gas cooling system, a synthesis gas purification system and a synthesis gas utilization system. The invention adopts the plasma gasification technology, and the medical waste is gasified at the high temperature of about 1100 ℃, so that the formation of dioxin toxic substances can be inhibited.

Description

Novel medical waste plasma gasification treatment system

Technical Field

The invention relates to the field of environment-friendly equipment, in particular to a novel medical waste plasma gasification treatment system.

Background

According to the annual newspaper for preventing and controlling the solid waste from polluting the environment in the large and medium cities issued by the Ministry of environmental protection in 2014, the medical waste treatment amount of the 261 large and medium cities in the country in 2013 is 54.21 ten thousand tons, and the treatment rate is only about one third of the medical waste generation amount in the country. In addition, as a considerable part of medical waste in China is treated together with industrial hazardous waste, the existing special medical waste treatment center is basically built and put into production before 2005 and is mainly distributed in main cities of each province. The problems of long construction age, untimely extension and the like also cause that the medical waste treatment scale of all the places at present can not basically meet the generation amount of medical waste in China.

Two treatment methods widely applied in China at present are high-temperature cooking (high-pressure) sterilization and pyrolysis incineration. But after the garbage is treated by a high-temperature sterilization method, the volume and the appearance are basically not changed, air pollutants can be discharged, odor is easy to generate, and substances such as formaldehyde, phenol, mercury and the like cannot be treated; the pyrolysis incineration method is not easy to realize stable combustion, the frequent change of the load of a tail gas system is easy to generate dioxin, a perfect tail gas purification system needs to be configured, and the bottom slag and the fly ash are harmful.

Along with the improvement of living standard of people, environmental protection consciousness is gradually enhanced, and the requirement for harmless treatment of medical waste is stricter and stricter. The medical waste treatment management system is gradually healthy, and the medical waste treatment technology meeting the national conditions is urgently needed in various places. The plasma furnace combines 2 processes of garbage high-temperature gasification and ash slag melting at 1350 ℃, so that the formation of dioxin toxic substances can be inhibited, and the vitreous slag generated by melting is harmless and can be recycled. The medical waste has high organic matter content, the medical waste is treated by using a plasma technology to obtain synthesis gas with high heat value, and the purified synthesis gas can be further utilized, such as power generation by using an internal combustion engine or fuel preparation, so that the aim of efficiently utilizing energy is fulfilled. Therefore, the plasma gasification technology can realize harmless, volume-reducing and volume-reducing treatment of medical waste to the maximum extent.

Disclosure of Invention

The invention aims to provide a novel plasma gasification treatment system for medical waste, which adopts a plasma gasification technology, can generate synthesis gas with high calorific value, can generate power through an internal combustion engine after purification, achieves the purpose of utilizing energy, and can also improve the economic benefit of enterprises.

The technical scheme for realizing the purpose is as follows: a novel medical waste plasma gasification treatment system is characterized by comprising a plasma furnace, wherein a synthesis gas outlet of the plasma furnace is sequentially connected with a synthesis gas cooling system, a synthesis gas purification system and a synthesis gas utilization system.

Furthermore, a compression condenser is connected between the synthesis gas purification system and the synthesis gas utilization system in series.

Furthermore, the synthesis gas cooling system comprises a heat exchanger and a cooling tower, wherein a heat medium inlet of the heat exchanger is connected with a synthesis gas outlet of the plasma furnace, a heat medium outlet of the heat exchanger is connected with the quenching tower, and the top end of the cooling tower is also provided with a NaOH solution injection device; the synthesis gas purification system comprises a wet electrostatic dust collector, a COS hydrolysis reactor and a washing tower which are sequentially connected.

Furthermore, the treatment system also comprises a sewage treatment system, and the waste water outlets of the quenching tower, the wet electrostatic dust collector, the COS hydrolysis reactor and the washing tower are respectively connected with the sewage treatment system.

Further, the synthesis gas utilization system is an internal combustion engine power generation system, and the synthesis gas is processed by the synthesis gas cooling system and the synthesis gas purification system and then is conveyed to the internal combustion engine power generation system to be used as power generation fuel.

Further, an exhaust gas outlet of the synthesis gas utilization system is connected with an SCR reactor.

Further, the plasma furnace comprises a furnace body, a feeding hole is formed in one side of the top of the furnace body, and a grate is arranged on the lower portion in the furnace body;

a primary air inlet pipe and a secondary air inlet pipe are arranged on the furnace body above the grate, the primary air inlet pipe is arranged above the secondary air inlet pipe, a plasma torch and a synthesis gas outlet are arranged on the furnace body below the grate, and a slag outlet is also arranged at the bottom of the furnace body.

Further, the bottom in the furnace body is also provided with a resistance heater.

Furthermore, the two primary air inlet pipes and the two secondary air inlet pipes are respectively symmetrically arranged on two sides of the furnace body; the primary air inlet pipe is obliquely arranged and forms an included angle of 60 degrees with the outer wall of the furnace body, and the secondary air inlet pipe is horizontally arranged; the two plasma torches are symmetrically arranged on two sides of the furnace body, and the torch nozzles of the plasma torches form an included angle of 30-45 degrees with the horizontal line.

Furthermore, the top of furnace body is provided with elevating system, and elevating system's output is connected with the telescopic link, and the telescopic link downwardly extending is to in the furnace body to the lower extreme is connected with broken burnt claw.

Furthermore, a refrigerant inlet of the heat exchanger is connected with an air source, and a refrigerant outlet of the heat exchanger is connected with a secondary air inlet pipe.

Furthermore, a feeding device is arranged on one side of the top of the furnace body and comprises a feeding hopper, a feeding hole is formed in one side of the feeding hopper, the outlet end of the feeding hopper is connected with a crusher, the outlet end of the crusher is connected with a first-stage shaftless screw conveyor, the outlet end of the first-stage shaftless screw conveyor is connected with a second-stage shafted screw conveyor, and the outlet end of the second-stage shafted screw conveyor is connected with the feeding hole in one side of the top of the furnace body; one side of the feed hopper is provided with a bucket hanging lifter, and bagged solid medical waste is input into the crusher through a feed inlet of the feed hopper by the bucket hanging lifter.

The operation of the present invention will be described in detail in the detailed description section.

The invention has the beneficial effects that:

the invention adopts the plasma gasification technology, and the medical waste is gasified at the high temperature of about 1100 ℃, so that the formation of dioxin toxic substances can be inhibited.

The invention adopts the plasma torch and the resistance heating element to provide a heat source, the ash slag is melted at the temperature of more than 1350 ℃, and the generated vitreous slag is harmless and can be recycled. On one hand, the land waste caused by landfill is solved, and on the other hand, certain economic benefits can be brought.

The invention overcomes the problems of low steam grade, serious environmental pollution and energy waste, low heat source utilization rate and the like generated by the traditional pyrolysis incineration treatment technology. .

The invention adopts the plasma gasification technology, can generate the synthesis gas with high heat value, and can generate electricity through the internal combustion engine after purification, thereby not only achieving the purpose of efficiently utilizing energy, but also improving the economic benefit of enterprises.

Clean synthesis gas from the compression condenser is combusted by an internal combustion engine to generate electricity, and the generated waste gas is discharged after reaching the standard after SCR denitration, so that the environmental pollution is avoided.

The bagged medical waste materials are crushed and enter the two-stage spiral conveying system, the winding resistance is very strong, the phenomena of arching and material blockage are not easy to occur to the feeding of strip-shaped and easily-wound materials such as cotton yarns, clothes and quilts and the like in the conveying of medical waste materials, the faults caused by blockage are prevented, and the dynamic continuous and stable feeding of medical waste can be realized.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

Detailed Description

As shown in fig. 1, the present invention includes a plasma furnace 1, and a heat exchanger 2, a quench tower 3, a wet electrostatic precipitator 4, a COS hydrolysis reactor 5, a scrubber 6, a compression condenser 7, and a syngas utilization system 8 are sequentially connected to a syngas outlet end of the plasma furnace 1.

The plasma furnace 1 comprises a furnace body 1-1, materials in the furnace body 1-1 are divided into a drying layer, a thermal decomposition layer, an oxidation layer and a reduction layer from top to bottom, a feeding hole 1-2 is arranged on one side of the top of the furnace body 1-1, and a fire grate 1-3 is arranged on the lower part in the furnace body 1-1; the furnace body 1-1 above the grate 1-3 is provided with two primary air inlet pipes 1-4 which are symmetrically arranged and two secondary air inlet pipes 1-5 which are symmetrically arranged, the primary air inlet pipes 1-4 are arranged above the secondary air inlet pipes 1-5, the primary air inlet pipes 1-4 are obliquely arranged and form an included angle a with the outer wall of the furnace body 1-1, the angle a =60 degrees, and the secondary air inlet pipes 1-5 are horizontally arranged.

A feeding device 10 is arranged on one side of the top of the furnace body 1, the feeding device 10 comprises a feeding hopper 10-1, a feeding port 10-1-1 is arranged on one side of the feeding hopper 10-1, the outlet end of the feeding hopper 10-1 is connected with a crusher 10-2, the outlet end of the crusher 10-2 is connected with a first-stage shaftless screw conveyor 10-3, the outlet end of the first-stage shaftless screw conveyor 10-3 is connected with a second-stage shafted screw conveyor 10-4, and the outlet end of the second-stage shafted screw conveyor 10-4 is connected with the feeding port 1-2 on one side of the top of the furnace body 1; one side of the feed hopper 10-1 is provided with a barrel hanging lifter 11, and the bagged solid medical waste is input into the pulverizer 10-2 through a feed inlet 10-1-1 of the feed hopper 10-1 by the barrel hanging lifter 11.

The primary air inlet pipe 1-4 is positioned on the drying layer and used for providing a small part of gasifying agent, and simultaneously adjusting the pressure of the upper space of the furnace body 1-1 to prevent gas with too low pressure from flowing back to the feed port 1-2 to cause the temperature of the feed port 1-2 to be too high.

The secondary air inlet pipes 1-5 are positioned between the thermal decomposition layer and the oxidation layer, provide a required gasifying agent for gasification reaction, are horizontally arranged, can generate high heat flux density near the secondary air nozzles, and can cause over-temperature fracture of the wall surface below the secondary air nozzles if the secondary air inlet pipes are obliquely arranged.

Two symmetrically arranged plasma torches 1-6 and two symmetrically arranged synthesis gas outlets 1-7 are arranged on a furnace body 1-1 of the synthesis gas refining area, the plasma torches 1-6 are arranged above the synthesis gas outlets 1-7, an included angle b is formed between a torch nozzle of each plasma torch 1-6 and a horizontal line, and b = 30-45 degrees.

The plasma torches 1-6 provide the high temperature of 1100-; meanwhile, the uncracked tar is further cracked in the refining zone, so that the tar content in the synthesis gas is further reduced.

The bottom in the furnace body 1-1 is also provided with a resistance heater 1-8, heating elements of the resistance heater 1-8 can adopt a silicon molybdenum rod, a silicon carbon rod and the like, the resistance heater and the plasma torch 1-6 provide high temperature of about 1350 ℃ for an ash melting area, and the ash is fully melted at the high temperature.

The two sides of the bottom of the furnace body 1-1 are respectively provided with a slag outlet 1-9.

The plasma furnace 1 is also provided with a coke breaking device to prevent the reaction zone in the furnace from slagging.

The coke breaking device comprises a lifting mechanism 1-10 arranged at the top end of the furnace body 1-1, the lifting mechanism 1-10 can adopt a hydraulic cylinder, the output end of the lifting mechanism 1-10 is connected with a coke breaking claw 1-12, a telescopic rod 1-11 extends downwards into the furnace body 1-1, the lower end of the telescopic rod is connected with the coke breaking claw 1-12, and the coke breaking claw 1-12 is three claw bodies connected to the periphery of the lower end of the telescopic rod 1-11.

A heat medium inlet and outlet of the heat exchanger 2 are connected between a synthetic gas outlet end of the plasma furnace 1 and the quench tower 3, a refrigerant inlet of the heat exchanger 2 is connected with an air source, and a refrigerant outlet of the heat exchanger 2 is connected with secondary air inlet pipes 1-5.

The top end of the cooling tower 3 is also provided with a NaOH solution spraying device 3-1.

The working wastewater of the quench tower 3, the wet electrostatic precipitator 4, the COS hydrolysis reactor 5 and the scrubber 6 is respectively delivered to a wastewater treatment system 9 for treatment.

The synthesis gas utilization system 8 is an internal combustion engine power generation system, synthesis gas generated by the plasma furnace 1 is processed by the synthesis gas cooling system and the synthesis gas purification system, and then is conveyed to the synthesis gas utilization system 8 to be used as power generation fuel, and an exhaust gas outlet of the synthesis gas utilization system 8 is connected with an SCR reactor 10.

The working principle of the invention is as follows:

the barrel hanging elevator 11 inputs the bagged solid medical garbage into the crusher 10-2 through the feeding port 10-1-1 of the feeding hopper 10-1, the bagged solid medical garbage is crushed by the crusher 10-2 and then sequentially input into the first-stage shaftless screw conveyor 10-3 and the second-stage shafted screw conveyor 10-4, and finally input into the plasma furnace 1, the materials in the plasma furnace 1 are divided into a drying layer, a thermal decomposition layer, an oxidation layer and a reduction layer from top to bottom, and the pyrolysis products are fully cracked through the hot oxidation layer and the reduction layer, so that the tar in the produced gas is greatly reduced.

The lower part of the grate 1-3 is divided into a synthetic gas refining area and an ash slag melting area in sequence, the crude synthetic gas from the reduction layer enters the synthetic gas refining area, and enters the heat exchanger 2 from a synthetic gas outlet after being reformed. The ash generated by the reduction layer falls into the bottom of the plasma furnace 1 through the grate 1-3, enters an ash melting zone for melting, and finally is discharged out of the plasma furnace 1 through a slag outlet 1-9. .

The temperature of the synthetic gas at 1050-1150 ℃ from the plasma furnace is reduced to about 500 ℃ through the heat exchanger 2, the part of heat is used for heating the working gas entering the plasma furnace 1 through the secondary air inlet pipe 1-5 for reaction, the temperature of the working gas entering the heat exchanger 2 is the local environment temperature, the outlet temperature is about 600 ℃, the working gas of the plasma furnace is heated by using the waste heat of the synthetic gas, and the energy consumption of a plasma torch can be effectively reduced by about 16%.

And (3) introducing the synthesis gas from the heat exchanger 2 into a quench tower 3, quenching to 150-200 ℃ in 1S, avoiding a resynthesis interval of dioxin, and removing acid gases such as hydrogen chloride and the like by using the sprayed NaOH solution. In consideration of the problems of ash discharge and cleaning, the vertical heat exchanger is adopted in the invention, and dust is slowly accumulated at the tail end of the heat exchanger and falls into the ash discharge port under the washing of flue gas to be discharged and treated.

The synthesis gas from the quench tower 3 enters a wet electrostatic dust collector 4 to remove particles, and the dust collection efficiency of the wet electrostatic dust collector 4 can reach more than 90%. The dust deposited on the polar plate during the operation of the wet electrostatic dust collector 4 can be washed off by water, and the washed off water is conveyed to a sewage treatment system by a sewage conveying pump.

The sulfur element in the synthesis gas exists mainly in two forms, i.e., organic sulfur and H2S, and the content of the organic sulfur accounts for about 20%. Since the sulfur element in the form of H2S is easier to be removed, the synthesis gas treated by the wet electrostatic precipitator 4 is sent to a COS hydrolysis reactor 5 to hydrolyze organic sulfur (COS) and convert it into H2S gas, which is then removed by a scrubber 6.

The high water content of the synthesis gas can directly influence the combustion characteristic of the synthesis gas as the fuel of the power generation system of the internal combustion engine, and the wet scrubbing and hydrolysis reaction can improve the water content of the synthesis gas in the flue gas purification process, so a compression condenser 7 is arranged in the synthesis gas purification process to remove water molecules in the synthesis gas, ensure that the synthesis gas can be stably combusted, and finally the synthesis gas is conveyed to a synthesis gas utilization system 8 to be used as the power generation fuel.

Claims

1. A novel medical waste plasma gasification treatment system is characterized by comprising a plasma furnace, wherein a synthesis gas outlet of the plasma furnace is sequentially connected with a synthesis gas cooling system, a synthesis gas purification system and a synthesis gas utilization system;

the plasma furnace comprises a furnace body, wherein materials in the furnace body are divided into a drying layer, a pyrolysis layer, an oxidation layer and a reduction layer from top to bottom;

a primary air inlet pipe and a secondary air inlet pipe are arranged on the furnace body above the grate, the primary air inlet pipe is arranged above the secondary air inlet pipe, the primary air inlet pipe is positioned on the drying layer, the secondary air inlet pipe is positioned between the thermal decomposition layer and the oxidation layer, a plasma torch and a synthetic gas outlet are arranged on the furnace body below the grate, and a slag outlet is also arranged at the bottom of the furnace body; the bottom in the furnace body is also provided with a resistance heater;

the two primary air inlet pipes and the two secondary air inlet pipes are respectively symmetrically arranged on two sides of the furnace body; the primary air inlet pipe is obliquely arranged and forms an included angle of 60 degrees with the outer wall of the furnace body, and the secondary air inlet pipe is horizontally arranged; the two plasma torches are symmetrically arranged on two sides of the furnace body, and the torch nozzles of the plasma torches form an included angle of 30-45 degrees with the horizontal line.

2. The novel medical waste plasma gasification treatment system according to claim 1, wherein a compression condenser is further connected in series between the synthesis gas purification system and the synthesis gas utilization system.

3. The novel medical waste plasma gasification treatment system according to claim 1 or 2, wherein the synthesis gas cooling system comprises a heat exchanger and a cooling tower, a heat medium inlet of the heat exchanger is connected with a synthesis gas outlet of the plasma furnace, a heat medium outlet of the heat exchanger is connected with a quenching tower, and a NaOH solution injection device is further mounted at the top end of the cooling tower; the synthesis gas purification system comprises a wet electrostatic dust collector, a COS hydrolysis reactor and a washing tower which are sequentially connected.

4. The novel medical waste plasma gasification treatment system according to claim 3, further comprising a sewage treatment system, wherein the waste water outlets of the quench tower, the wet electrostatic precipitator, the COS hydrolysis reactor and the scrubber tower are respectively connected with the sewage treatment system.

5. The novel medical waste plasma gasification treatment system according to claim 1 or 2, wherein an exhaust gas outlet of the synthesis gas utilization system is connected with an SCR reactor, the synthesis gas utilization system is an internal combustion engine power generation system, and the synthesis gas treated by the synthesis gas cooling system and the synthesis gas purification system is delivered to the internal combustion engine power generation system to serve as power generation fuel.

6. The novel medical waste plasma gasification treatment system according to claim 1, wherein a lifting mechanism is arranged at the top end of the furnace body, an output end of the lifting mechanism is connected with a telescopic rod, the telescopic rod extends downwards into the furnace body, and the lower end of the telescopic rod is connected with a coke breaking claw.

7. The novel medical waste plasma gasification treatment system according to claim 3, wherein a refrigerant inlet of the heat exchanger is connected with an air source, and a refrigerant outlet of the heat exchanger is connected with a secondary air inlet pipe.

8. The novel medical waste plasma gasification treatment system according to claim 1, wherein: a feeding device is arranged on one side of the top of the furnace body, the feeding device comprises a feeding hopper, a feeding hole is formed in one side of the feeding hopper, the outlet end of the feeding hopper is connected with a crusher, the outlet end of the crusher is connected with a first-stage shaftless screw conveyor, the outlet end of the first-stage shaftless screw conveyor is connected with a second-stage shafted screw conveyor, and the outlet end of the second-stage shafted screw conveyor is connected with the feeding hole in one side of the top of the furnace body; one side of the feed hopper is provided with a bucket hanging lifter, and bagged solid medical waste is input into the crusher through a feed inlet of the feed hopper by the bucket hanging lifter.