CN105737163A - Household garbage internal circulation sealed low-temperature pyrolysis system and method based on decoupling combustion - Google Patents

Abstract

The invention discloses a closed-type low-temperature pyrolysis system based on decoupling combustion for internal circulation of domestic garbage. The pyrolysis section includes a drying drum and a pyrolysis drum, the gas scrubbing section includes two-stage scrubbing towers, and the heat recovery section includes flue gas, Pyrolysis gas waste heat recovery device. In the present invention, domestic garbage is first sent to the drying drum for drying, and then sent to the pyrolysis drum for pyrolysis to generate pyrolysis gas and carbon residue. Drying and pyrolysis are divided into a start-up stage and a normal operation stage. After the gas is mixed, it passes through the burners of the drying drum and the pyrolysis drum to burn in the cavity of the drying drum and the pyrolysis drum to generate high-temperature flue gas; during normal operation, the high-temperature flue gas in the cavity of the pyrolysis drum is sent to Heat exchange and drying are carried out in the cavity of the drying drum, and the burner of the drying drum becomes an auxiliary heat source; the pyrolysis gas is purified through the first-level and second-level scrubbing towers in turn. The invention makes full use of the waste heat to produce high-temperature steam, and the flue gas is discharged after being cooled and purified, effectively controlling the generation of dioxins, and realizing resource utilization, reduction and low-carbonization of domestic garbage.

Description

Closed Low-Temperature Pyrolysis System and Method Based on Decoupling Combustion

technical field

The invention relates to the harmless treatment of household garbage and its resource recycling technology, in particular to a closed-type low-temperature pyrolysis system and method based on decoupled combustion for internal circulation of household garbage.

Background technique

Now, my country produces more than 200 million tons of municipal solid waste every year, and the annual growth rate of waste has reached more than 10%. In recent years, although some achievements have been made in the treatment of domestic waste in my country, the overall capacity is still obviously insufficient. The growth rate of waste treatment capacity obviously lags behind the growth rate of waste generation. The suburbs have occupied a large area of land, and some cities are already facing the threat of "garbage siege".

At present, there are three main methods of municipal solid waste treatment widely used in my country and even in the world, including landfill, incineration, and composting. Among them, landfill is the main way to deal with municipal solid waste in my country, and the amount of waste treated accounts for about 10% of the total amount of waste. 80%. However, the landfill treatment method has disadvantages such as occupying a large amount of land resources, polluting leachate, and methane gas produced by fermentation intensifying the greenhouse effect. However, the composting method has problems such as a large area, a long conversion process, difficult to stabilize the state, and difficult to control the product quality. At the same time, the waste treated by composting in my country is basically mixed waste, which has not been strictly classified, so it is inevitable in the composting process. Mixing a large amount of toxic and harmful substances such as heavy metals, coupled with the unorganized emission of methane and other greenhouse gases, can easily cause serious pollution to the surrounding environment. Among the above three methods, the incineration method is the most effective treatment method for waste reduction, which can reduce the volume of waste by 85% and the weight by more than 75%. However, incineration of waste has hidden dangers of environmental pollution, especially the dioxin produced by incineration Ying has irreversible "three-induced" toxicity, which is extremely harmful to human health, and has become the most concerned issue at present. In addition, there are some restrictions on the incineration of waste:

(1) Municipal solid waste in China is basically mixed and collected, with complex components, and incineration generally requires the minimum calorific value of waste to be above 3360kJ·kg ^-1 , when the calorific value of waste is too low, it is necessary to add fuel to assist combustion, so It will cause an increase in operating costs. At present, except for a few economically developed cities in China, garbage sorting and collection in other cities have not been widely carried out, so the calorific value of mixed domestic garbage is low, which is not suitable for incineration;

(2) The investment and operating costs of incineration treatment equipment are relatively high. Most of the waste incineration power plants built in my country in the early stage imported foreign technology and equipment, and the investment cost was expensive. In recent years, with the localization of imported equipment and independent innovation of technology, domestic Technology and equipment have been developed and applied. Although the investment in incineration plant units has decreased, the investment and operating costs of incineration treatment are still high for areas with average economic affordability.

Compared with the incineration method, the more advanced pyrolysis technology is a decomposition reaction carried out in an oxygen-free or hypoxic reducing environment, which not only has the same reduction characteristics as the incineration method, but also produces secondary pollution. There are fewer emission substances, so it has a good application prospect. In addition, pyrolysis technology converts useful substances in waste into gaseous (gas) or liquid (tar) forms for use respectively. These gaseous and liquid fuels are more efficient and less polluting than direct combustion of solid waste. At present, domestic waste pyrolysis treatment technology has been studied to a certain extent, such as the invention patent with the publication number CN103242134A and the name "A Method for Pyrolysis and Gasification Purification of Household Waste". Under certain conditions, oxygen is introduced to carry out combustion and cracking reactions, and the combustible gas generated by the pyrolysis of garbage is used comprehensively to synthesize chemical raw materials to realize the resource utilization of domestic waste. Complicated, so this increases the difficulty of synthesizing chemical raw materials, and the treatment of garbage under high temperature and aerobic conditions, the subsequent purification process costs are high, and the exhaust emissions are also large. Another example is an invention patent with the publication number CN102660306A and the name "Countercurrent Rotary Domestic Garbage Pyrolysis Carbonization Furnace System and Garbage Treatment Process". heat source to achieve waste reduction and recycling, but this process does not dry and pretreat domestic waste, but uses a method of drying while pyrolyzing, which will increase the energy consumption of the system and reduce the processing efficiency. The direct discharge of flue gas after cooling treatment will also have a certain impact on the atmospheric environment, especially in today's society plagued by smog, the follow-up treatment of flue gas cannot be ignored. Therefore, in view of the existing problems in the existing patented technology and its application, it is of great scientific and social and economic significance to further study and improve the waste pyrolysis treatment process, reduce the generation of secondary pollution emissions, and reduce the difficulty of tail gas treatment.

Contents of the invention

The technical problem to be solved by the present invention is to provide a closed-type low-temperature pyrolysis system and method based on decoupled combustion of domestic waste, which can reduce the generation of secondary pollution and discharge substances, reduce the difficulty of tail gas treatment, and make full use of the waste produced by the system. products, reducing energy consumption and improving process efficiency.

In order to solve the above technical problems, the present invention provides an internal circulation closed low-temperature pyrolysis system for domestic waste based on decoupled combustion, including a pyrolysis section, a gas scrubbing section and a heat recovery section, wherein the pyrolysis section includes a drying drum and a pyrolysis drum , the scrubbing section includes a primary scrubber, a secondary scrubber and a settling tank, and the heat recovery section includes a flue gas waste heat recovery device and a pyrolysis gas waste heat recovery device;

The drying drum includes a drying feeder, a drying drum inner drum, a drying drum outer cylinder and a drying drum burner; the inlet of the drying feeder is connected with the feeding device through a transmission mechanism, and the outlet of the drying feeder is connected with the drying drum. The inner drum of the drying drum is connected; the inner drum of the drying drum and the outer drum of the drying drum are of a sealed structure and a cavity is formed between them; the rear end of the inner drum of the drying drum is provided with a water vapor outlet and a mixed garbage outlet , the water vapor outlet is connected with a sewage treatment device; the outer cylinder of the drying drum is provided with a gas inlet and a flue gas outlet communicating with the cavity of the drying drum; the burner of the drying drum is arranged on the outer wall of the inner drum of the drying drum superior;

The pyrolysis drum includes a pyrolysis feeder, a pyrolysis drum inner drum, a pyrolysis drum outer cylinder, a pyrolysis drum burner and a gas-solid separator; the inlet of the pyrolysis feeder passes through a transmission mechanism and a drying drum The mixed garbage outlet of the inner drum is connected, and the outlet of the pyrolysis feeder is connected with the inner drum of the pyrolysis drum; the inner drum of the pyrolysis drum and the outer drum of the pyrolysis drum are of a sealed structure and a gap Cavity; the outer cylinder of the pyrolysis drum is provided with a gas inlet and a flue gas outlet communicating with the cavity of the pyrolysis drum, and the flue gas outlet is communicated with the gas inlet on the outer cylinder of the drying drum, and the gas inlet is supplied with air and a gas storage The gas in the pyrolysis drum enters; the pyrolysis drum burner is arranged on the outer wall of the inner drum of the pyrolysis drum, and the gas-solid separator communicates with the rear end of the inner drum of the pyrolysis drum, which has a pyrolysis gas outlet and A charcoal slag outlet, which is connected to a charcoal slag collecting device;

Both the first-level scrubber and the second-level scrubber have a gas inlet, a gas outlet and a liquid storage tank, the gas inlet of the first-level scrubber communicates with the pyrolysis gas outlet of the gas-solid separator, and the second-level scrubber The gas inlet of the first gas scrubber is connected with the gas outlet of the primary gas scrubber, the gas outlet of the secondary gas scrubber is connected with the gas storage, and the liquid in the liquid storage tank of the primary gas scrubber and the secondary gas scrubber enters the settling tank for precipitation;

The flue gas waste heat recovery device has a high-temperature flue gas inlet, a low-temperature flue gas outlet, a low-temperature medium inlet, and a high-temperature medium outlet. The pyrolysis gas waste heat recovery device includes a circulating water inlet, a circulating water outlet, a low-temperature medium inlet, and a high-temperature medium outlet. The high-temperature flue gas inlet of the recovery device is connected to the flue gas outlet on the outer cylinder of the drying drum, the low-temperature flue gas outlet is connected to the atmosphere, the circulating water inlet of the pyrolysis gas waste heat recovery device is connected to the water outlet of the secondary scrubber, and the circulating water The outlet is connected to the gas inlet of the secondary gas scrubber, the low-temperature medium inlet of the flue gas waste heat recovery device and the pyrolysis gas waste heat recovery device are both connected to the lower water outlet of a high-temperature steam storage, the flue gas waste heat recovery device and the pyrolysis gas waste heat The high-temperature medium outlets of the recovery device are all communicated with the steam inlets of the high-temperature steam storage.

Further, both the outer surface of the outer cylinder of the drying drum and the outer surface of the outer cylinder of the pyrolysis drum are covered with an insulation layer of 80-120mm aluminum silicate or rock wool.

Further, the pyrolysis section also includes a squeeze dehydration device arranged between the feeding device and the drying drum. Preferably, the extrusion dehydration device includes a crusher and an extruder, the inlet of the crusher is connected with the feeding device through a transmission mechanism, the outlet of the crusher is connected with the inlet of the extruder through a transmission mechanism, and the The outlet is connected with the inlet of the dry feeder through a transmission mechanism.

Wherein, both the drying feeder and the pyrolysis feeder are screw feeders.

Further, the pyrolysis drum burners are evenly distributed on the outer wall of the inner drum of the pyrolysis drum located in the outer drum of the pyrolysis drum.

Further, the gas scrubbing section also includes a cyclone dust removal device located in front of the primary gas scrubber, the inlet of the cyclone dust removal device communicates with the pyrolysis gas outlet of the gas-solid separator in the pyrolysis section, and the outlet communicates with the primary scrubber. The gas inlet of the gas tower is connected.

Wherein, the first-stage scrubber adopts a quenching type, and the second-stage scrubber is equipped with a dynamic wave scrubber.

Wherein, both the flue gas waste heat recovery device and the pyrolysis gas waste heat recovery device are heat pipe heat exchangers.

Further, the inner wall of the outer cylinder of the drying drum is provided with a thread structure for guiding flue gas.

The present invention also provides a closed-type low-temperature pyrolysis method based on decoupled combustion of domestic waste, including:

1) Send the domestic waste into the inner drum of the drying drum for drying treatment, and discharge most of the water in the domestic waste to the sewage treatment device. The drying temperature is controlled at 120°C-200°C, and the drying time is controlled at 0.5h-1h. The speed of the inner drum is controlled at 4-8rpm;

The dried domestic waste is sent to the inner drum of the pyrolysis drum for pyrolysis treatment to generate pyrolysis gas and carbon residue. The pyrolysis temperature is controlled at 400°C-600°C, and the pyrolysis time is controlled at 0.5h-1h. The speed of the inner drum is controlled at 4-8rpm;

The drying treatment and pyrolysis treatment of domestic waste are divided into start-up phase and normal operation phase;

In the start-up phase, the air and the gas output from the gas storage are mixed and then burned in the cavity of the drying drum and the cavity of the pyrolysis drum through the drying drum burner and the pyrolysis drum burner to generate high-temperature flue gas;

After the start-up phase is completed and the normal operation phase is completed, the high-temperature flue gas in the cavity of the pyrolysis drum is transported to the cavity of the drying drum to perform heat exchange and drying on the domestic waste in the drum of the drying drum, and the burner of the drying drum is switched to an auxiliary heat source. After the air and the gas output from the gas storage are mixed, they continue to burn through the pyrolysis drum burner in the cavity of the pyrolysis drum to generate high-temperature flue gas. Water enters the flue gas waste heat recovery device for heat exchange, and the water flowing out from the lower part of the high-temperature steam storage absorbs the heat of the flue gas to form high-temperature steam, which enters the high-temperature steam storage, and the waste heat of the flue gas is absorbed and discharged;

2) The pyrolysis gas is sent to the gas washing section, and is purified through the first-level gas scrubber and the second-level gas scrubber in turn, and the washed pyrolysis gas enters the gas storage;

The high-temperature circulating water of the secondary scrubber and the water flowing out of the lower part of the high-temperature steam storage enter the pyrolysis gas waste heat recovery device for heat exchange, and the water flowing out of the lower part of the high-temperature steam storage absorbs the heat of the high-temperature circulating water of the secondary scrubbing tower to form a high temperature The steam enters the high-temperature steam storage, and the high-temperature circulating water in the secondary scrubber releases waste heat and circulates back to the secondary scrubber.

Preferably, before the domestic waste enters the drying drum, it is mechanically cut in a shredder, and then dehydrated in an extruder.

Preferably, before the pyrolysis gas enters the primary scrubber, it is firstly dedusted in a cyclone dedusting device.

Wherein, the first-stage gas scrubber sprays the pyrolysis gas with alkaline cold water, and the second-stage gas scrubber performs dynamic wave washing on the pyrolysis gas output from the first-stage gas scrubber.

The benefits of the present invention are:

1) Using low-temperature pyrolysis technology, domestic waste does not need to be sorted specially. The waste heat of the system is used to dry and pretreat the waste before entering the pyrolysis drum, which increases the pyrolysis treatment capacity by 50%. materials, effectively reduce heat loss, save energy consumption, and control heat loss within 30%;

2) The clean pyrolysis gas provides the combustion medium for the drying drum burner and pyrolysis drum burner in the start-up phase and the pyrolysis drum burner in the normal operation phase in the way of internal recycling and combustion. Multiple burners are arranged to make the inner drum of the pyrolysis drum evenly heated and fully pyrolyzed;

3) The gas washing section adopts a cascade purification process, which passes through two-stage gas scrubbers in sequence, and uses alkaline liquid spray and dynamic wave scrubber to remove tar and dust in the pyrolysis gas, and at the same time, the flue gas is removed after cooling and purification treatment Chlorides that lead to dioxins are eliminated, the tar content is finally lower than 1.2%, PM emissions meet the standards, and the pyrolysis gas (gas) is stored after waste heat recovery; the whole system fully recovers waste heat, and finally produces both clean gas and high-temperature steam. Such products, the clean gas produced can fully meet the needs of waste pyrolysis, and the surplus part will be output as products.

Description of drawings

The accompanying drawing is a schematic diagram of the system principle of the present invention.

Wherein the reference signs are explained as follows:

1 is the extrusion dehydration device; 1-1 is the crusher; 1-2 is the extruder; 2 is the drying drum; 2-1 is the inner drum of the drying drum; 2-2 is the outer cylinder of the drying drum; 2-3 is Drying drum burner; 2-4 is the screw feeder; 3 is the pyrolysis drum; 3-1 is the inner drum of the pyrolysis drum; 3-2 is the outer drum of the pyrolysis drum; 3-3 is the combustion of the pyrolysis drum 3-4 is a gas-solid separator; 3-5 is a screw feeder; 4 is a cyclone dust removal device; 5 is a gas washing section; 5-1 is a first-level scrubber; Gas tower; 6 is settling tank; 7 is pyrolysis gas waste heat recovery device; 8 is flue gas waste heat exchanger; 9 is gas storage; 10 is high-temperature steam storage; 11 is fan; 12 is sewage treatment device; 13 is charcoal Slag collection device; A is air; F is high-temperature flue gas; W is clear water; S is high-temperature steam product; G is gas product.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The domestic waste internal cycle closed low-temperature pyrolysis system based on decoupled combustion provided by the present invention, as shown in the accompanying drawings, includes a pyrolysis section, a scrubbing section, and a heat recovery section, wherein the pyrolysis section includes a drying drum 2 and a pyrolysis section. Drum 3, scrubbing section 5 includes primary scrubber 5-1, secondary scrubber 5-2 and settling tank 6, heat recovery section includes flue gas waste heat recovery device and pyrolysis gas waste heat recovery device; wherein:

The drying drum 2 includes a drying feeder, a drying drum inner drum 2-1, a drying drum outer drum 2-2 and a drying drum burner 2-3; the inlet of the drying feeder passes through a conveying mechanism (such as a conveyor belt, the same below) It is connected with the feeding device, and the outlet of the drying feeder is communicated with the inner drum 2-1 of the drying drum; the inner drum 2-1 of the drying drum and the outer drum 2-2 of the drying drum are in a sealed structure and a gap is formed between the two. cavity; the rear end of the drum 2-1 in the drying drum is provided with a water vapor outlet and a mixed garbage outlet, and the water vapor outlet is connected with a sewage treatment device 12; Gas inlet and flue gas outlet; the drying drum burner 2-3 is arranged on the outer wall of the drying drum inner drum 2-1;

The pyrolysis drum 3 includes a pyrolysis feeder, a pyrolysis drum inner drum 3-1, a pyrolysis drum outer cylinder 3-2, a pyrolysis drum burner 3-3 and a gas-solid separator 3-4; The inlet of the feeder is connected to the mixed waste outlet of the inner drum 2-1 of the drying drum through the transmission mechanism, and the outlet of the pyrolysis feeder is connected with the inner drum 3-1 of the pyrolysis drum; the inner drum 3-1 of the pyrolysis drum 1 and the pyrolysis drum outer cylinder 3-2 are sealed structures and a cavity is formed between them; the pyrolysis drum outer cylinder 3-2 is provided with a gas inlet and a flue gas outlet communicating with the pyrolysis drum cavity. The flue gas outlet communicates with the gas inlet on the outer cylinder 2-2 of the drying drum, and the gas inlet is supplied by air and gas in a gas storage 9; the pyrolysis drum burner 3-3 is arranged on the inner drum 3-1 of the pyrolysis drum The gas-solid separator 3-4 communicates with the rear end of the inner drum 3-1 of the pyrolysis drum, and has a pyrolysis gas outlet and a carbon residue outlet, and the carbon residue outlet is connected to a carbon residue collection device 13 connections;

The first-level scrubber 5-1 and the second-level scrubber 5-2 all have a gas inlet, a gas outlet and a liquid storage tank, and the gas inlet of the first-level scrubber 5-1 is connected to the heat of the gas-solid separator 3-4. The solution gas outlet is connected, the gas inlet of the secondary scrubber 5-2 is connected with the gas outlet of the primary scrubber 5-1, the gas outlet of the secondary scrubber 5-2 is connected with the gas storage 9, and the gas outlet of the primary scrubber 5-2 is connected. The liquid in the liquid storage tank of the gas tower 5-1 and the secondary gas scrubber 5-2 enters the settling tank 6 for precipitation;

The flue gas waste heat recovery device has a high-temperature flue gas inlet, a low-temperature flue gas outlet, a low-temperature medium inlet, and a high-temperature medium outlet. The pyrolysis gas waste heat recovery device includes a circulating water inlet, a circulating water outlet, a low-temperature medium inlet, and a high-temperature medium outlet. The high-temperature flue gas inlet of the recovery device is connected to the flue gas outlet on the outer cylinder 2-2 of the drying drum, the low-temperature flue gas outlet is connected to the atmosphere, and the circulating water inlet of the pyrolysis gas waste heat recovery device is connected to the secondary scrubber 5-2. The water outlet is connected, the circulating water outlet is connected with the gas inlet of the secondary gas scrubber 5-2, the low-temperature medium inlet of the flue gas waste heat recovery device and the pyrolysis gas waste heat recovery device are both connected with the lower water outlet of a high-temperature steam storage 10, Both the high-temperature medium outlets of the flue gas waste heat recovery device and the pyrolysis gas waste heat recovery device communicate with the steam inlet of the high-temperature steam storage 10 .

The two ends of the inner drum 2-1 of the drying drum extend out of the outer drum 2-2 of the drying drum, and the two ends of the inner drum 3-1 of the pyrolysis drum also extend out of the outer drum 3-2 of the pyrolysis drum. In order to heat the inner drum 3-1 of the pyrolysis drum evenly to achieve sufficient pyrolysis, the burners 3-3 of the pyrolysis drum are evenly distributed in the inner drum 3-1 of the pyrolysis drum located in the outer drum 3-2 of the pyrolysis drum on the outer wall.

In addition, in order to effectively reduce the heat loss of the drying drum 2 and the pyrolysis drum 3, the outer surface of the drying drum outer cylinder 2-2 and the outer surface of the pyrolysis drum outer cylinder 3-2 are covered with 80-120mm aluminum silicate Insulation layer or rock wool insulation layer.

Preferably, the pyrolysis section also includes a squeeze dehydration device 1 located between the feeding device and the drying drum 2, the squeeze dehydration device 1 includes a crusher 1-1 and an extruder 1-2, and the crusher The entrance of 1-1 is connected with the feeding device (such as grab bucket, hopper) through the transmission mechanism, the exit of the crusher 1-1 is connected with the entrance of the extruder 1-2 through the transmission mechanism, and the extruder 1-2 The outlet is connected with the inlet of the dry feeder through a transmission mechanism.

In the aforementioned structure, both the drying feeder and the pyrolysis feeder are screw feeders 2-4, 3-5, which can push domestic garbage into the drying drum inner drum 2-1 and the pyrolysis drum In the drum 3-1.

More preferably, the gas scrubbing section also includes a cyclone dust removal device 4 before the primary gas scrubber 5-1. The pyrolysis gas outlet of -4 is connected, and the outlet is connected with the gas inlet of the first-stage scrubber 5-1.

In the above system, the primary scrubber 5-1 adopts the quenching type of alkaline cold water spray, and the secondary scrubber 5-2 is equipped with a dynamic wave scrubber. The flue gas waste heat recovery device and the pyrolysis gas waste heat recovery device are respectively a heat pipe type pyrolysis gas waste heat recovery device 7 and a heat pipe type flue gas waste heat heat exchanger 8 .

In addition, the inner wall of the outer cylinder 2-2 of the drying drum is provided with a threaded structure, which can guide the high-temperature flue gas in the cavity of the drying drum to run.

The closed low-temperature pyrolysis method based on the decoupled combustion of the above-mentioned system includes:

1) Send domestic waste to the inner drum 2-1 of the drying drum for drying treatment, and discharge most of the water in the domestic waste to the sewage treatment device 12, wherein the drying temperature is controlled at 120°C-200°C, and the drying time is controlled at 0.5h -1h, the speed of the inner drum is controlled at 4-8rpm;

The dried domestic waste is sent to the inner drum 3-1 of the pyrolysis drum for pyrolysis treatment, and pyrolysis gas and carbon residue are generated. The pyrolysis temperature is controlled at 400°C-600°C, and the pyrolysis time is controlled at 0.5h- 1h, the speed of the inner drum is controlled at 4-8rpm;

The drying treatment and pyrolysis treatment of domestic waste are divided into start-up phase and normal operation phase;

In the start-up phase, the air A delivered by the fan 11 and the gas G output from the gas storage 9 are mixed and passed through the drying drum burner 2-3 and the pyrolysis drum burner 3-3 respectively in the drying drum cavity and the pyrolysis drum cavity Combustion heat supply produces high temperature flue gas;

After the start-up phase is completed and enters the normal operation phase, the high-temperature flue gas F in the cavity of the pyrolysis drum is transported to the cavity of the drying drum to perform heat exchange and drying on the domestic garbage in the drum 2-1 in the drying drum, and the drying drum burner 2 -3 is switched to an auxiliary heat source, the air A delivered by the fan 11 is mixed with the gas G output by the gas storage 9, and then continues to burn through the pyrolysis drum burner 3-3 in the cavity of the pyrolysis drum to generate high-temperature flue gas F. The heat-exchanged flue gas in the cavity of the drying drum (the temperature drops to 180°C-200°C) and the water flowing out from the lower part of the high-temperature steam storage 10 (the temperature is about 80°C) enter the flue gas waste heat recovery device 8 for heat exchange. The water flowing out from the lower part of the steam storage 10 absorbs the heat of the flue gas to form high-temperature steam and enters the high-temperature steam storage 10. After the waste heat of the flue gas is absorbed, the temperature drops to 105°C and can be discharged directly;

2) The pyrolysis gas is sent to the scrubbing section 5, and is purified through the primary scrubber 5-1 and the secondary scrubber 5-2 in turn, and the cleaned pyrolysis gas enters the gas storage 9;

The high-temperature circulating water of the secondary gas scrubber 5-2 and the water flowing out from the lower part of the high-temperature steam storage 10 enter the pyrolysis gas waste heat recovery device for heat exchange, and the water flowing out of the lower part of the high-temperature steam storage 10 absorbs the secondary gas scrubber 5-2 The heat of the high-temperature circulating water forms high-temperature steam and enters the high-temperature steam storage 10, and the high-temperature circulating water in the secondary scrubber 5-2 releases waste heat and circulates back to the secondary scrubber 5-2;

The high-temperature steam S in the high-temperature steam storage 10 and the surplus gas G in the gas storage 9 are finally output as products.

Preferably, before the household garbage enters the drying drum 2, it is picked up in batches by grab buckets and sent to the crusher 1-1, and the pieces of household garbage after fully mechanically cutting are then sent to the extruder 1-2 for dehydration through the conveyor belt. The moisture content of the rubbish after being squeezed and dehydrated can be reduced to 50%, and after passing through the drying drum 2, the moisture content of the discharged mixed rubbish is further reduced to 40%.

In the water washing section 5, the clear water W is sent to the primary scrubber 5-1 and the secondary scrubber 5-2, and in the primary scrubber 5-1, the pyrolysis gas is sprayed with alkaline cold water, The temperature of the gas drops rapidly, so that the tar condenses, and the tar condensed into small droplets and the dust in the gas are stripped by alkaline water together and fall into the liquid storage tank of the first-stage scrubber 5-1. The secondary gas scrubber 5-2 is equipped with a power wave scrubber, and the liquid (including clean water and water flowing back to the secondary gas scrubber 5-2 after heat exchange by the pyrolysis gas waste heat exchanger 7) is reversely sprayed into In the scrubber, the gas and liquid discharged from the primary scrubber 5-1 collide, forming a stable standing wave in close contact with the gas and liquid on the contact surface. Effectively remove residual tar and dust in pyrolysis gas. The liquid in the liquid storage tank of the two-stage gas scrubber is pumped into the settling tank 6 by the circulating pump for sedimentation, the light oil in the uppermost layer is directly separated and stored, the sewage in the middle layer is sent to the water treatment system, and the heavy oil and ash in the bottom layer are separated and stored. discharge.

The present invention has been described in detail through specific embodiments above, which are only preferred embodiments of the present invention, and are not intended to limit the present invention. Without departing from the principle of the present invention, all other embodiments obtained by persons of ordinary skill in the art through any modification, equivalent replacement, improvement, etc. without creative work shall be considered as included in the present invention. within the technical scope of protection.

Claims (14)

1. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning, it is characterized in that, including pyrolysis section, gas washing section and heat-recovery section, wherein pyrolysis section includes drying drum and pyrolysis drum, gas washing section includes one-level aeration tower, two grades of aeration towers and Sedimentation tank, and heat-recovery section includes flue gas waste heat recovery apparatus and pyrolysis gas waste-heat recovery device；

Described drying drum includes rotating cylinder, drying drum urceolus and drying drum burner in dry batcher, drying drum；The entrance of described dry batcher is connected with feeding device by connecting gear, and the outlet of dry batcher connects with rotating cylinder in drying drum；In described drying drum, rotating cylinder and drying drum urceolus are for sealing structure and being formed with therebetween cavity；In described drying drum, the rear end of rotating cylinder is provided with moisture outlet and composting outlet, this moisture outlet and sewage-treatment plant connection；Described drying drum urceolus is provided with the gas access and exhanst gas outlet that connect with drying drum cavity；On the lateral wall that described drying drum burner is arranged in drying drum rotating cylinder；

Described pyrolysis drum includes rotating cylinder in pyrolysis batcher, pyrolysis drum, pyrolysis drum urceolus, pyrolysis drum burner and gas-solid separator；The entrance of described pyrolysis batcher is connected with the composting outlet of rotating cylinder in drying drum by connecting gear, and the outlet of pyrolysis batcher connects with rotating cylinder in pyrolysis drum；In described pyrolysis drum, rotating cylinder and pyrolysis drum urceolus are for sealing structure and being formed with therebetween cavity；Described pyrolysis drum urceolus is provided with the gas access and exhanst gas outlet that connect with pyrolysis drum cavity, and this exhanst gas outlet connects with the gas access on drying drum urceolus, and gas access enters for the combustion gas in air and a combustion gas memorizer；Described pyrolysis drum burner is arranged in pyrolysis drum on the lateral wall of rotating cylinder, and described gas-solid separator connects with the rear end of rotating cylinder in pyrolysis drum, and it has pyrolysis gas outlet and breeze outlet, and the outlet of this breeze is connected with a breeze collection device；

Described one-level aeration tower and two grades of aeration towers are respectively provided with gas access, gas outlet and liquid storage tank, the pyrolysis gas outlet of the gas access of one-level aeration tower and gas-solid separator, the gas access of two grades of aeration towers connects with the gas outlet of one-level aeration tower, the gas outlet of two grades of aeration towers connects with combustion gas memorizer, and in the liquid storage tank of one-level aeration tower and two grades of aeration towers, liquid enters Sedimentation tank precipitation；

Flue gas waste heat recovery apparatus has high-temperature flue gas entry, low-temperature flue gas exports, cryogenic media entrance and high-temperature medium outlet, pyrolysis gas waste-heat recovery device includes recirculated water entrance, circulating water outlet, cryogenic media entrance and high-temperature medium outlet, the high-temperature flue gas entry of flue gas waste heat recovery apparatus connects with the exhanst gas outlet on drying drum urceolus, low-temperature flue gas outlet and atmosphere, the outlet connection of the recirculated water entrance of pyrolysis gas waste-heat recovery device and two grades of aeration towers, the gas access connection of circulating water outlet and two grades of aeration towers, flue gas waste heat recovery apparatus all connects with the bottom outlet of a high-temperature steam memorizer with the cryogenic media entrance of pyrolysis gas waste-heat recovery device, flue gas waste heat recovery apparatus exports with the high-temperature medium of pyrolysis gas waste-heat recovery device and all connects with the steam inlet of high-temperature steam memorizer.

2. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterized in that, the outer surface of the outer surface of described drying drum urceolus and pyrolysis drum urceolus is all covered with aluminium silicate heat-insulation layer or the rock wool heat-preservation layer of 80-120mm.

3. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterised in that described pyrolysis section also includes the squeezing dehydration device being located between feeding device and drying drum.

4. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterized in that, described squeezing dehydration device includes disintegrating machine and extruder, the entrance of disintegrating machine is connected with feeding device by connecting gear, the outlet of disintegrating machine is connected with the entrance of extruder by connecting gear, and the outlet of extruder is connected by the entrance of connecting gear with dry batcher.

5. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1 or 4, it is characterised in that described dry batcher and pyrolysis batcher are spiral batcher.

6. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterised in that described pyrolysis drum burner is evenly distributed on the lateral wall of the pyrolysis drum rotating cylinder being positioned at pyrolysis drum urceolus.

7. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterized in that, described gas washing section also includes the cyclone dust collector before being positioned at one-level aeration tower, the entrance of this cyclone dust collector and the pyrolysis gas outlet of gas-solid separator in pyrolysis section, outlet connects with the gas access of one-level aeration tower.

8. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterised in that described one-level aeration tower adopts quenching, equipped with dynamic wave scrubber in two grades of aeration towers.

9. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterised in that described flue gas waste heat recovery apparatus and pyrolysis gas waste-heat recovery device are heat-pipe heat exchanger.

10. the closed low temperature pyrogenation system of the house refuse internal recycle based on decoupling burning according to claim 1, it is characterised in that the inwall of described drying drum urceolus is provided with the helicitic texture guiding flue gas.

11. one kind adopts the closed low temperature pyrogenation method of the house refuse internal recycle based on decoupling burning that system described in claim 1 realizes, it is characterised in that including:

1) the interior rotating cylinder that house refuse is sent into drying drum is dried process, the most of moisture of house refuse is expelled to sewage-treatment plant, wherein baking temperature controls, at 120 DEG C 200 DEG C, to control drying time at 0.5h-1h, and the rotating speed of interior rotating cylinder controls at 4-8rpm；

The interior rotating cylinder that dried house refuse is sent into pyrolysis drum carries out pyrolysis processing, generates pyrolysis gas and breeze, and wherein pyrolysis temperature controls at 400 DEG C 600 DEG C, and pyrolysis time controls at 0.5h-1h, and interior rotating cylinder rotating speed controls at 4-8rpm；

The startup stage that the dried of house refuse and pyrolysis processing being divided into and the normal operation stage；

Startup stage, air and combustion gas memorizer output combustion gas mixing after by drying drum burner and pyrolysis drum burner respectively drying drum cavity and pyrolysis drum cavity in combustion heat supplying produce high-temperature flue gas；

Startup stage, completes to enter after the normal operation stage, high-temperature flue gas in pyrolysis drum cavity is delivered in drying drum cavity the house refuse in rotating cylinder in drying drum is carried out heat exchange dries, drying drum burner switches to auxiliary thermal source, continue through pyrolysis drum burner combustion heat supplying in pyrolysis drum cavity after the combustion gas mixing of air and the output of combustion gas memorizer and produce high-temperature flue gas, the water flowed out through the flue gas of heat exchange and high-temperature steam memorizer bottom in drying drum cavity enters in flue gas waste heat recovery apparatus and carries out heat exchange, the water that high-temperature steam memorizer bottom is flowed out absorbs the heat of flue gas and is formed in high-temperature steam entrance high-temperature steam memorizer, fume afterheat is discharged after being absorbed；

2) pyrolysis gas being sent into gas washing section, pass sequentially through one-level aeration tower and two grades of aeration towers carry out purified treatment, the pyrolysis gas after washing enters combustion gas memorizer；

The water that the high temperature circulation water of two grades of aeration towers and high-temperature steam memorizer bottom are flowed out enters in pyrolysis gas waste-heat recovery device and carries out heat exchange, the water that high-temperature steam memorizer bottom is flowed out absorbs the heat of the high temperature circulation water of two grades of aeration towers and is formed in high-temperature steam entrance high-temperature steam memorizer, and the high temperature circulation water of two grades of aeration towers discharges waste heat and loops back two grades of aeration towers.

12. the closed low temperature pyrogenation method of the house refuse internal recycle based on decoupling burning according to claim 11, it is characterised in that before house refuse enters drying drum, first in disintegrating machine, carry out machine cuts, in extruder, then carry out dehydration.

13. the closed low temperature pyrogenation method of the house refuse internal recycle based on decoupling burning according to claim 11, it is characterised in that before pyrolysis gas enters one-level aeration tower, first in cyclone dust collector, carry out dust removal process.

14. the closed low temperature pyrogenation method of the house refuse internal recycle based on decoupling burning according to claim 11, it is characterized in that, pyrolysis gas is carried out alkalescence cold water spray by described one-level aeration tower, and the pyrolysis gas that one-level aeration tower is exported by two grades of aeration towers carries out dynamic wave scrubbing.