CN210796350U

CN210796350U - External combustion type agriculture and forestry waste pyrolysis system

Info

Publication number: CN210796350U
Application number: CN201921765367.7U
Authority: CN
Inventors: 甄恩明; 李淑芬
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-10-21
Filing date: 2019-10-21
Publication date: 2020-06-19
Anticipated expiration: 2029-10-21

Abstract

The utility model discloses an external combustion formula agriculture and forestry discarded object pyrolysis system relates to agriculture and forestry discarded object pyrolysis technical field. The pyrolysis system comprises an external combustion type square pyrolysis furnace, a pyrolysis gas treatment device and a control device, wherein the pyrolysis furnace consists of a feeding section, a gas collection section, a pyrolysis section and a discharging section which are sequentially communicated from top to bottom; a forward material conveying device and a reverse material conveying device are arranged at the bottom of the feeding section in parallel up and down; and a pressure difference measuring device is arranged between the lower part of the pyrolysis section and the gas collection section. The pyrolysis gas treatment device comprises a primary separator, a condensing device, a secondary separator, a pyrolysis gas pressurizing device and a special combustion chamber which are connected by pipelines; the side wall of the gas collection section is provided with a first gas guide pipe which is communicated with the primary separator, the pyrolysis gas pressurizing device is communicated with the pyrolysis section through a second gas guide pipe, and the second gas guide pipe is provided with a combustion-supporting air pipeline. The agricultural and forestry wastes are subjected to external combustion pyrolysis to obtain the biochar, vinegar liquid and fuel gas, the operation is reliable, the automation is easy to realize, and no secondary pollution is generated.

Description

External combustion type agriculture and forestry waste pyrolysis system

Technical Field

The utility model relates to an agriculture and forestry discarded object pyrolysis technical field, concretely relates to external combustion formula agriculture and forestry discarded object pyrolysis system.

Background

With the improvement of living standard, the living energy in rural areas is also changed from agricultural and forestry waste to clean energy such as electricity, liquefied gas, natural gas and the like. A large amount of agricultural and forestry wastes are abandoned, so that field pollution, fire and insect pest hidden dangers are caused. How to utilize agricultural and forestry wastes with various forms and change waste into valuable becomes a problem which needs to be solved urgently.

The existing agricultural and forestry waste pyrolysis system has the problems of poor efficiency, low automation degree, secondary pollution and poor raw material adaptability. The existing pyrolysis system depends on manual judgment too much, so that the phenomena of under burning and over burning exist in the pyrolysis process, and the pyrolysis efficiency is reduced. The existing pyrolysis system has the phenomenon that products in gas generated in the pyrolysis process are separated into liquid products, and the liquid products are expected to be sold as commodities. This risk depends on market conditions, and when sales are not smooth, the liquid product cannot be handled and secondary pollution is generated. Due to the diversity of agricultural and forestry wastes, the conventional pyrolysis system is quite passive in treatment, and when the pyrolysis system capable of consuming the materials is converted into another material, the problems of unsmooth feeding, unsmooth discharging, bridge building and the like exist.

Chinese patent CN208829594U discloses an internal combustion internal heating type biomass continuous carbonization system, which is used for feeding biomass raw materials from the top, and sequentially carrying out drying and carbonization processes. Combustible gas generated in the carbonization process enters a purification device, and wood tar and pyroligneous liquid in the combustible gas is separated out. Part of the generated combustible gas enters the furnace for circulation, and the rest is discharged outwards. This patent suffers from the following drawbacks:

1. biomass raw materials are different from coal, and are various in variety and poor in bulk material fluidity. The gas collection umbrella in this patent is in the middle of the stove, and the phenomenon of taking a bridge very easily appears in the operation in-process, causes the system operation unusual, even compels to shut down.

2. The circulating fuel gas is heated in the furnace and then mixed with newly generated pyrolysis gas in the process of flowing upwards, and the temperature is lower the more upwards, so that tar is condensed. These coagulated tars act as binders to bind the biomass feedstock. In combination with the factors in 1, the bridging phenomenon of the biomass raw material is more obvious.

Chinese patent CN201610454492 discloses a continuous biomass charcoal gas co-production device. The furnace body top has the feed inlet, down is drying chamber and carbomorphism room in proper order, sets up first through-hole on the furnace body lateral wall at carbomorphism roof portion, and the high temperature flue gas that the combustion chamber produced gets into the stove through first through-hole. The side wall in the discharge hopper at the lower part of the carbonization chamber is provided with a gas outlet which is used for guiding combustible gas generated in the carbonization process out of the furnace and entering the combustion chamber for combustion. This patent has the following drawbacks:

1. because the vent holes are positioned on the side wall, raw materials at the core part of the hearth are insufficiently heated. When the particle size of the raw material is small, the core is not heated sufficiently and is hard to be carbonized. This structure also makes it impossible to handle small particle size materials with a particle size of less than 30 mm.

2. Difficulty in enlarging round hearth

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an external combustion formula agriculture and forestry discarded object pyrolysis system carries out the external combustion pyrolysis with the agriculture and forestry discarded object, obtains biochar, vinegar liquid and gas, realizes the agriculture and forestry discarded object that can consume various forms, and is efficient, and the operation is reliable, easily realizes automaticly, does not produce secondary pollution's purpose.

In order to solve the technical problem, the utility model adopts the following technical scheme: an external combustion type agriculture and forestry waste pyrolysis system is characterized in that: the device comprises an external combustion type square pyrolysis furnace, a pyrolysis gas treatment device and a control device, wherein the external combustion type square pyrolysis furnace consists of a feeding section, a gas collection section, a pyrolysis section and a discharging section which are sequentially communicated from top to bottom; a forward material conveying device and a reverse material conveying device are arranged at the bottom of the feeding section in parallel up and down; a differential pressure measuring device is arranged between the lower part of the pyrolysis section and the gas collection section; the pyrolysis gas treatment device comprises a primary separator, a condensing device, a secondary separator, a pyrolysis gas pressurizing device and a special combustion chamber which are sequentially connected through pipelines; the gas collection section is provided with a first gas guide pipe on the side wall, the first gas guide pipe is communicated with the primary separator, the pyrolysis gas pressurizing device is communicated with the pyrolysis section through a second gas guide pipe, and the second gas guide pipe is provided with a combustion-supporting air pipeline.

A further technical proposal is that an isolation baffle is arranged between the forward material conveying device and the reverse material conveying device.

The bottom of the feeding section is connected with a waste material channel, the waste material channel extends into the gas collection section, and a cavity between the outer side wall of the waste material channel and the inner side wall of the gas collection section forms a gas collection chamber.

A further technical scheme is that a temperature sensor is arranged inside the gas collection chamber.

A further technical scheme is that a plurality of A-shaped flame paths are arranged at the bottom of the pyrolysis section in parallel, the tops of the A-shaped flame paths are sharp, the bottoms of the A-shaped flame paths are wide, and a combustion chamber is arranged in the A-shaped flame paths.

The further technical proposal is that the sharp top of the A-shaped flame path is vertically and upwards arranged, and the included angle between the side wall and the horizontal direction is not less than the stacking angle of the pyrolysis materials; and temperature sensors are arranged inside the A-shaped flame path and above the A-shaped flame path.

A further technical scheme is that the discharging section is sequentially provided with a first-stage discharging valve and a second-stage discharging valve from top to bottom, and the first-stage discharging valve and the second-stage discharging valve are opened alternately in sequence.

The technical scheme is that the condensing device and the liquid outlet of the secondary separator are communicated with a feed inlet of a vinegar liquid temporary storage device through pipelines, one discharge outlet of the vinegar liquid temporary storage device is communicated with a vinegar liquid storage device through a pipeline, the other discharge outlet of the vinegar liquid temporary storage device is connected with one end of a pressure pump through a pipeline, and the other end of the pressure pump is connected with a special combustion chamber through a pipeline.

The further technical proposal is that the liquid outlet of the first-stage separator is connected with one end of a booster pump through a pipeline, and the other end of the booster pump is connected with a special combustion chamber through a pipeline.

According to a further technical scheme, the external combustion type square pyrolysis furnace further comprises a material lifting device, and a discharge hole of the material lifting device is connected with a feed hole in the top of the feeding section.

The working principle is as follows: open the pyrolysis system through controlling means, the feeding section top is gone up to the conveying through material hoisting device to the forestry and agricultural residues, and the material is because of self gravity down fall into feeding section bottom, and forward passes the material device and transports it to discharging channel top, and the material drops on reverse biography material device, passes the material device motion along the reverse and until getting into the pyrolysis section along discharging channel. The forward material transfer device and the reverse material transfer device can be used as a baffle plate for preventing pyrolysis gas from escaping from the feeding section while transferring materials.

The gas and air mixed combustion in the A-shaped flame path, the produced high-temperature flue gas flows upwards, and carries out reverse heat exchange with the waste falling downwards, the material continuously moves downwards, the temperature is gradually increased, and the pyrolysis reaction is carried out to generate biochar and pyrolysis gas. The amount of flue gas is small, and after the flue gas is mixed with pyrolysis gas, the mixture is still called pyrolysis gas. The biochar enters the discharging section, the first-stage valve is opened, the biochar enters the discharging section and then is closed, the second-stage valve is opened after the biochar is put out a fire and is cooled, and the biochar is discharged out of the pyrolysis furnace.

Pyrolysis gas up flows and gets into the collection chamber, get into the primary separator through first air duct, the tar of primary separator in with pyrolysis gas is separated out, remaining pyrolysis gas is through condensing equipment condensation, the separation of secondary separator, separate vinegar liquid, remaining incoagulable combustible gas is through pyrolysis gas pressure device pressurization back, partly gets into special combustion chamber burning, partly a font flame path that gets into the pyrolysis section through the second air duct burns, the high temperature flue gas that the burning formed lasts and carries out the heat exchange with the discarded object, with this operation of maintaining the pyrolysis oven.

The separated tar is pressurized and atomized by a pressurizing pump and then enters a special combustion chamber for combustion. The separated vinegar liquid can be stored for reuse, and can also be atomized by a booster pump and then enters a special combustion chamber for combustion. The vinegar liquid and the tar are separated and treated, so that secondary pollution is avoided.

The control device controls the actions of all parts of the pyrolysis furnace and the pyrolysis treatment device, simultaneously adjusts the proportion of combustible gas and combustion air according to data fed back by the temperature sensor, controls the waste treatment capacity according to the pressure difference measuring device between the gas collection section and the pyrolysis section, and realizes the automatic control of the equipment.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the tar is separated by a first-stage separator, the vinegar liquid is separated by a condensing device and a second-stage separator, and the tar and the vinegar liquid are separated and then treated, so that secondary pollution is avoided.

2. The forward material conveying device conveys materials to the upper part of the reverse material conveying channel, and the materials enter the pyrolysis section along with the reverse material conveying device on the reverse material conveying device. The forward and reverse material conveying device can be used as a baffle for preventing pyrolysis gas from escaping from the feeding section while conveying materials, so that sealed feeding is realized, and the safety and the sanitation of the operating environment of the pyrolysis furnace are ensured.

3. The structure of the feeding section can ensure that the external combustion type square pyrolysis furnace can treat agricultural and forestry wastes in various forms, and the problem of unsmooth feeding is greatly avoided.

4. The pyrolysis oven is square, and through setting up the A font flame path of suitable quantity, positive reverse material conveying device, the pyrolysis oven that sets up not unidimensional that can be convenient.

5. The gas collection section is positioned at the upper part of the pyrolysis furnace, a gas collection umbrella is replaced, and pyrolysis gas directly enters the pyrolysis gas treatment device through the first gas guide pipe, so that the bridging problem is avoided.

6. High-temperature gas and material reverse heat transfer, the abundant pyrolysis and the carbonization of the material of being convenient for realize the automated control of equipment through controlling means, and the operation is stable, and production efficiency is high, the facilitate promotion.

Drawings

Fig. 1 is a schematic structural diagram of the pyrolysis system of the present invention.

Fig. 2 is a front view of the external combustion type square pyrolysis furnace of the utility model.

Fig. 3 is a left view of the external combustion type square pyrolysis furnace of the utility model.

Fig. 4 is a schematic diagram of the conveying of the material in the feeding section of the present invention.

In the figure: 1-external combustion type square pyrolysis furnace, 11-feeding section, 111-forward material transfer device, 112-reverse material transfer device, 113-isolation baffle, 114-waste material channel, 12-gas collection section, 121-gas collection chamber, 13-pyrolysis section, 131-A-shaped flame path, 14-discharging section, 141-first-stage discharging valve, 142-second-stage discharging valve, 21-first-stage separator, 22-condensing device, 23-second-stage separator, 24-pyrolysis gas pressurizing device, 25-special combustion chamber, 26-vinegar liquid temporary storage device, 27-vinegar liquid storage device, 28-pressurizing pump, 31-first air guide pipe, 32-second air guide pipe, 33-combustion air pipeline, 4-material lifting device, 5-temperature sensor and 6-differential pressure measuring device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the following description of the present invention will be made in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

Fig. 1 shows: an external combustion type agriculture and forestry waste pyrolysis system is characterized in that: the device comprises an external combustion type square pyrolysis furnace 1, a pyrolysis gas treatment device and a control device, wherein the external combustion type square pyrolysis furnace is composed of a feeding section 11, a gas collection section 12, a pyrolysis section 13 and a discharging section 14 which are sequentially communicated from top to bottom; the bottom of the feeding section 11 is provided with a forward material conveying device 111 and a reverse material conveying device 112 in parallel up and down.

The pyrolysis gas treatment device comprises a first-stage separator 21, a condensing device 22, a second-stage separator 23, a pyrolysis gas pressurizing device 24 and a special combustion chamber 25 which are sequentially connected through pipelines. The first separator 21 is a tar separator, the second separator 23 is a vinegar separator, and the pyrolysis gas pressurizing device 24 is preferably a fan.

A first gas-guide tube 31 is arranged on the side wall of the gas collection section 12, the first gas-guide tube 31 is communicated with the primary separator 21, the pyrolysis gas pressurizing device 24 is communicated with the pyrolysis section 13 through a second gas-guide tube 32, and a combustion-supporting air pipeline 33 is arranged on the second gas-guide tube 32; and a differential pressure measuring device 6 is arranged between the lower part of the pyrolysis section 13 and the gas collection section 12.

As shown in FIG. 4, the agricultural and forestry waste enters through the feeding port of the feeding section 11, enters the forward material conveying device 111 under the action of self gravity, then enters the reverse material conveying device 112, and enters the pyrolysis section 13 from the outlet of the reverse material conveying device 112. The forward material conveying device 111 and the reverse material conveying device 112 use a spiral conveying device, pyrolysis gas is prevented from escaping from the feeding section while material is conveyed, sealed feeding is formed, and safety and sanitation of the operation environment of the pyrolysis furnace are guaranteed. A differential pressure measuring device 6 is arranged between the lower part of the pyrolysis section 13 and the gas collection section 12, thereby controlling the feeding amount of the feeding section.

Preferably for fully exchanging heat with the waste, a plurality of A-shaped flame paths 131 are arranged at the bottom of the pyrolysis section 13 in parallel, and the top and the bottom of the A-shaped flame paths 131 are wide and provided with a combustion chamber inside. The high temperature flue gas that the combustion chamber produced carries out reverse heat transfer with the discarded object that drops, and the material continues to move down, and the pyrolysis takes place pyrolytic reaction and generates biochar and pyrolysis gas, and the biochar gets into the ejection of compact section and discharges the pyrolysis oven after putting out a fire the cooling.

The pyrolysis gas mixed with the high-temperature flue gas flows upwards to enter the gas collection chamber 12 and enters the primary separator 21 through the first gas guide pipe 31, tar in the pyrolysis gas is separated out by the primary separator 21, the rest pyrolysis gas is condensed by the condensing device 22, vinegar liquid is separated out by the separation of the secondary separator 23, the rest non-condensable combustible gas is pressurized by the pyrolysis gas pressurizing device 24, one part of the non-condensable combustible gas enters the special combustion chamber 25, the other part of the non-condensable combustible gas enters the A-shaped flame path 131 of the pyrolysis section 13 through the second gas guide pipe 32 to be combusted, and the high-temperature flue gas formed by combustion continuously exchanges heat with waste, so that the operation of the pyrolysis furnace is maintained. The tar is separated by a first-stage separator, the vinegar liquid is separated by a condensing device and a second-stage separator, and the tar and the vinegar liquid are separated and then treated, so that secondary pollution is avoided.

In order to make the pyrolysis section 13 burn sufficiently, a combustion air pipeline 33 is arranged on the second air duct 32, and air is introduced into a flame path of the pyrolysis section 13.

To further prevent the escape of pyrolysis gas from the feeding section 11, isolation baffles 113 are provided at the forward direction material transfer device 111 and the reverse direction material transfer device 112.

In order to facilitate material conveying, a material lifting device 4 is arranged on the side wall of the pyrolysis furnace 1, so that materials are lifted from the furnace bottom to the furnace top, and automatic feeding is realized.

Example 2

In order to further optimize the technical solution in embodiment 1, in this embodiment, a waste material channel 114 is connected to the bottom of the feed section 11, the waste material channel 114 extends into the gas collecting section 12, and a cavity between an outer side wall of the waste material channel 114 and an inner side wall of the gas collecting section 12 forms a gas collecting chamber 121. As shown in fig. 2, the gas collection chamber 121 arranged close to the furnace wall replaces a common gas collection umbrella, and the gas collection chamber 121 enables the gas collection section to form a large cavity structure with a large upper area and a small lower area, so that the pyrolysis gas can be conveniently led out; meanwhile, the conical discharging channel 114 can enable waste raw materials to be smoothly discharged, and stable operation of the pyrolysis furnace is guaranteed.

In order to facilitate smooth discharge of the material subjected to pyrolysis carbonization, the sharp top of the A-shaped flame path 131 is vertically and upwards arranged, and the included angle between the side wall and the horizontal direction is not smaller than the stacking angle of the pyrolysis material, so that the flame path is prevented from being blocked. The lower part of the pyrolysis section adopts an A-shaped channel made of heat-resistant materials as a flame path. The distance between the flame paths is adjusted according to the properties of the raw materials, the adjustment range is 100-600mm, and the pyrolysis device can be suitable for pyrolysis of waste raw materials with the thickness of 5-150 mm. The flame paths are uniformly distributed in the hearth of the pyrolysis furnace, so that the raw materials in the furnace are uniformly heated.

In order to enable the control device to adjust the proportion of the combustible gas and the combustion air according to data fed back by the temperature sensors, the temperature sensors 5 are arranged inside the A-shaped flame path 131, above the A-shaped flame path 131 and inside the gas collection chamber 121.

For the convenience of the fire extinguishing and temperature reduction of the biochar, the discharging section 14 is sequentially provided with a first-stage discharging valve 141 and a second-stage discharging valve 142 from top to bottom, and the first-stage discharging valve 141 and the second-stage discharging valve 142 are opened alternately in sequence. As shown in fig. 3, the biochar enters the discharging section 14, the control device opens the first-stage valve 141, the biochar enters the discharging section and then is closed, the biochar extinguishes and cools the fire, and then the control device controls the second-stage valve 142 to open, and the biochar is discharged out of the pyrolysis furnace and then is closed.

Example 3

In order to further optimize the technical scheme in the embodiment 1, in this embodiment, the liquid discharge ports of the condensing device 22 and the secondary separator 23 are communicated with the feed port of the vinegar liquid temporary storage device 26 through a pipeline, one discharge port of the vinegar liquid temporary storage device 26 is communicated with the vinegar liquid storage device 27 through a pipeline, the other discharge port of the vinegar liquid temporary storage device is connected with one end of a pressurizing pump 28 through a pipeline, and the other end of the pressurizing pump 28 is connected with the special combustion chamber 25 through a pipeline. The liquid outlet of the first-stage separator 21 is connected with one end of a booster pump 28 through a pipeline, and the other end of the booster pump 28 is connected with the special combustion chamber 25 through a pipeline.

The separated tar is pressurized and atomized by a pressurizing pump 28 through a liquid outlet of the first-stage separator 21 and then enters a special combustion chamber 25 for combustion. The condensing device 22 condenses and separates out a part of vinegar liquid, the other part is separated by the secondary separator 23, the separated vinegar liquid completely enters the vinegar liquid temporary storage device 26, and the vinegar liquid can be transferred to the vinegar liquid storage device 27 for reuse when necessary. Or pressurized by a pressurizing pump 28 and then enters the special combustion chamber 25 for atomized combustion. The vinegar liquid and the tar are separated and treated, and secondary pollution can be avoided by adopting a complete combustion mode.

While the invention has been described herein with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this invention. More particularly, various variations and modifications are possible in the component parts or arrangements within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts or arrangements, other uses will also be apparent to those skilled in the art.

Claims

1. An external combustion type agriculture and forestry waste pyrolysis system is characterized in that: the device comprises an external combustion type square pyrolysis furnace (1), a pyrolysis gas treatment device and a control device, wherein the external combustion type square pyrolysis furnace is composed of a feeding section (11), a gas collection section (12), a pyrolysis section (13) and a discharging section (14) which are sequentially communicated from top to bottom;

a forward material conveying device (111) and a reverse material conveying device (112) are arranged at the bottom of the feeding section (11) in parallel up and down;

a differential pressure measuring device (6) is arranged between the lower part of the pyrolysis section (13) and the gas collection section (12);

the pyrolysis gas treatment device comprises a primary separator (21), a condensing device (22), a secondary separator (23), a pyrolysis gas pressurizing device (24) and a special combustion chamber (25) which are sequentially connected through pipelines;

the gas collection section (12) is provided with a first gas guide pipe (31) on the side wall, the first gas guide pipe (31) is communicated with the primary separator (21), the pyrolysis gas pressurizing device (24) is communicated with the pyrolysis section (13) through a second gas guide pipe (32), and the second gas guide pipe (32) is provided with a combustion-supporting air pipeline (33).

2. The external combustion type agricultural and forestry waste pyrolysis system of claim 1, wherein: an isolation baffle (113) is arranged between the forward material conveying device (111) and the reverse material conveying device (112).

3. The external combustion type agricultural and forestry waste pyrolysis system of claim 1, wherein: the bottom of the feeding section (11) is connected with a waste channel (114), the waste channel (114) extends into the gas collection section (12), and a cavity between the outer side wall of the waste channel (114) and the inner side wall of the gas collection section (12) forms a gas collection chamber (121).

4. The external combustion type agricultural and forestry waste pyrolysis system of claim 3, wherein: and a temperature sensor (5) is arranged in the gas collection chamber (121).

5. The external combustion type agricultural and forestry waste pyrolysis system of claim 1, wherein: a plurality of A-shaped flame paths (131) are arranged at the bottom of the pyrolysis section (13) in parallel, and a combustion chamber is arranged in the narrow top and the wide bottom of the A-shaped flame paths (131).

6. The external combustion type agricultural and forestry waste pyrolysis system of claim 5, wherein: the sharp top of the A-shaped flame path (131) is vertically arranged upwards, and the included angle between the side wall and the horizontal direction is not less than the stacking angle of pyrolysis materials; temperature sensors (5) are arranged inside the A-shaped flame path (131) and above the A-shaped flame path (131).

7. The external combustion type agricultural and forestry waste pyrolysis system of claim 1, wherein: the discharging section (14) is sequentially provided with a first-stage discharging valve (141) and a second-stage discharging valve (142) from top to bottom, and the first-stage discharging valve (141) and the second-stage discharging valve (142) are opened alternately in sequence.

8. The external combustion type agricultural and forestry waste pyrolysis system of claim 1, wherein: the liquid outlet of the condensing device (22) and the liquid outlet of the secondary separator (23) are communicated with the feed inlet of a vinegar liquid temporary storage device (26) through pipelines, one discharge outlet of the vinegar liquid temporary storage device (26) is communicated with a vinegar liquid storage device (27) through a pipeline, the other discharge outlet of the vinegar liquid temporary storage device is connected with one end of a pressure pump (28) through a pipeline, and the other end of the pressure pump (28) is connected with a special combustion chamber (25) through a pipeline.

9. The external combustion type agricultural and forestry waste pyrolysis system of claim 1, wherein: and a liquid outlet of the primary separator (21) is connected with one end of a booster pump (28) through a pipeline, and the other end of the booster pump (28) is connected with the special combustion chamber (25) through a pipeline.

10. The external combustion type agricultural and forestry waste pyrolysis system according to any one of claims 1 to 9, wherein: the external combustion type square pyrolysis furnace (1) further comprises a material lifting device (4), and a discharge hole of the material lifting device (4) is connected with a feed hole in the top of the feeding section (11).