A biomass pyrolysis device with positive system operating pressure

Abstract

The present invention relates to a biomass pyrolysis device with a positive system operating pressure, comprising a rotary kiln, a bladeless booster fan, a spray tower, a gas booster fan, a packing tower, an electrostatic precipitator, a gas temporary storage buffer cabinet, a feeding system and a pipeline system. The beneficial effects are as follows: the device of the invention can make the rotary kiln operate at a slightly positive pressure, which is maintained by an appropriate amount of recirculated purified gas, the spray tower operates at a positive pressure, the gas pressure is provided by the bladeless booster fan arranged at the outlet of the rotary kiln, the feed port of the rotary kiln adopts a double-layer plug-in valve and inert sealing gas is introduced into the interlayer for sealing, and conventional scale seals can be adopted between the rotary kiln and the kiln head and kiln tail sealing covers, and the device has the characteristics of simple structure, easy implementation, stable operation, safety and reliability, not easy to be blocked, and low system failure rate.

Description

Technical Field

[0001] The invention relates to the technical field of biomass pyrolysis treatment, and in particular to a biomass pyrolysis device with a positive system operating pressure. Background Art

[0002] Pyrolysis is one of the methods for processing biomass, which usually includes equipment such as a pyrolysis furnace and its gas purification facilities. At present, the pure dry distillation pyrolysis rotary kiln device produces pyrolysis gas by pyrolyzing biomass fuel in an externally heated rotary kiln. The pressure of the pyrolysis gas generated in the rotary kiln of this device is very low. If an induced draft fan is directly installed after the rotary kiln purification device, the equipment in front of the induced draft fan is very likely to form a negative pressure, and air may leak into the system equipment. Once air leaks into the pyrolysis furnace and the purification device, it may cause the pyrolysis furnace to explode. At the same time, once the pyrolysis gas mixed with excessive air enters the purification device equipped with an electrostatic precipitator, it will cause the electrostatic precipitator to explode. Therefore, the pyrolysis gas generating device operating at negative pressure is explicitly prohibited in the specification. Therefore, whether the operating pressure of each device in the system can be effectively controlled is the key to whether the system can be allowed to produce safely. Summary of the invention

[0003] In order to overcome the defects of the prior art, the technical problem solved by the present invention is to provide a biomass pyrolysis device with a positive system operating pressure, which has a simple structure, is easy to implement, operates stably, is safe and reliable, is not easy to clog, and has a low system failure rate.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A biomass pyrolysis device with a positive system operating pressure, comprising a rotary kiln, a bladeless booster fan, a spray tower, a gas booster fan, a packing tower, an electrostatic precipitator, a gas temporary storage buffer cabinet, a feeding system and a pipeline system, characterized in that the rotary kiln is composed of a rotary kiln head sealing cover, a rotary kiln tail sealing cover and a pressure measuring point, wherein the rotary kiln head sealing cover and the rotary kiln tail sealing cover are both provided with pressure measuring points, which are respectively arranged at the two ends of the rotary kiln; the bladeless booster fan is arranged at the outlet end of the rotary kiln and is connected to the spray tower, and the spray tower is connected to the gas booster fan, the packing tower, the electrostatic precipitator and the gas temporary storage buffer cabinet in sequence; the pipeline system The system consists of a pipeline, a bladeless booster fan inlet valve, a rotary kiln head sealing cover inlet valve and a branch pipeline, wherein one end of the pipeline is connected to the gas temporary storage buffer cabinet, and the other end is connected to the rotary kiln head sealing cover through the rotary kiln head sealing cover inlet valve, and the bladeless booster fan inlet valve is arranged on the branch pipeline between the bladeless booster fan and the pipeline; the feeding system consists of a feed hopper, a double-layer plug-in door and an inert gas sealing pipeline, wherein there are two double-layer plug-in doors, which are arranged on the feed hopper at a certain distance, the inert gas sealing pipeline is connected to the feed hopper and is located between the two double-layer plug-in doors, and the feed hopper is arranged at the entrance end of the rotary kiln.

[0006] The bladeless booster fan has no blades in its gas flow channel, and what enters the interior is the purified gas from the gas temporary storage buffer cabinet. The gas enters the cylindrical air duct interlayer from the radial pipe in the channel, and high-speed gas is ejected from the outlet to provide power for the pyrolysis gas generated by the rotary kiln.

[0007] The pressure measuring point is interlocked with the inlet valve of the rotary kiln head sealing cover for control.

[0008] The sealing inert gas is preferably nitrogen.

[0009] The circulating spraying liquid in the spray tower is alkali solution.

[0010] The gas booster blower is preferably a glass fiber reinforced plastic centrifugal blower.

[0011] A biomass pyrolysis process with a positive system operating pressure, characterized by comprising the following process steps and methods:

[0012] 1) Control the micro-positive pressure of the rotary kiln: According to the feedback from the pressure measuring points set at both ends of the rotary kiln, by adjusting the opening size of the inlet valve of the rotary kiln head sealing cover, the flow rate of the recirculated purified gas entering the rotary kiln can be controlled, so that the rotary kiln can operate at a micro-positive pressure;

[0013] 2) Providing power for the pyrolysis gas before the inlet of the gas booster fan: By adjusting the opening size of the inlet valve of the bladeless booster fan, the air volume of the purified gas from the gas temporary storage buffer cabinet entering the bladeless booster fan is controlled, and the purified gas is pressurized by the power fan in the bladeless booster fan to form a high-speed jet airflow, which is ejected from the air outlet of the bladeless gas channel wall, and the pyrolysis gas flow is driven by the viscosity of the gas and the local pressure drop formed, providing the power required for the rotary kiln to produce pyrolysis gas; the bladeless booster fan provides a slightly excess amount of purified pyrolysis gas so that the inlet of the gas booster fan always maintains a positive pressure without causing a negative pressure;

[0014] 3) Control the gas booster fan outlet to positive pressure: Because the power provided by the booster fan without blades is relatively small, the gas booster fan configured in the system should be arranged as far forward as possible; the booster fan with blades cannot adapt to a large amount of dust and tar, so the gas booster fan is arranged between the spray tower and the packing tower to provide the main power for the pyrolysis gas, so that the gas booster fan outlet equipment can operate stably at positive pressure.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) The present invention can realize positive pressure operation of the rotary kiln and gas purification devices;

[0017] 2) The present invention uses a bladeless fan, so that the first stage boosting position is basically not blocked by dust and tar;

[0018] 3) The present invention uses an alkali solution spray tower in front of the booster fan. The fan is made of glass fiber reinforced plastic. The booster fan is less likely to be blocked by a large amount of dust and tar, and is less likely to be corroded by an acidic gas atmosphere. The operating life of subsequent equipment is longer.

[0019] 4) The present invention sets a recirculating net pyrolysis gas inlet point at the feed point of the rotary kiln head, which can ensure that the pressure in the rotary kiln is positive;

[0020] 5) The present invention solves the safety of equipment operation through a conventional and simple sealing method, and the overall cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the process principle of the present invention.

[0022] In the figure: 1-rotary kiln 1-1-shaking head sealing cover 1-2-kiln tail sealing cover 1-3-pressure measuring point 2-bladeless booster fan 3-spray tower 4-gas booster fan 5-packing tower 6-electric dust collector 7-gas temporary storage buffer cabinet 8-feeding hopper 8-1-double-layer plug-in door 8-2-inert gas sealing pipeline 9-pipeline 9-1-bladeless booster fan inlet valve 9-2-rotary kiln head sealing cover inlet valve 9-3-branch pipeline DETAILED DESCRIPTION

[0023] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0024] See Figure 1As shown, the present invention relates to a biomass pyrolysis device with a positive system operating pressure, comprising a rotary kiln 1, a bladeless booster fan 2, a spray tower 3, a gas booster fan 4, a packing tower 5, an electrostatic precipitator 6, a gas temporary storage buffer cabinet 7, a feeding system and a pipeline system, wherein the rotary kiln 1 is composed of a rotary kiln head sealing cover 1-1, a rotary kiln tail sealing cover 1-2 and a pressure measuring point 1-3, wherein the rotary kiln head sealing cover 1-1 and the rotary kiln tail sealing cover 1-2 are both provided with pressure measuring points 1-3, which are respectively arranged at both ends of the rotary kiln 1; the bladeless booster fan 2 is arranged at the outlet end of the rotary kiln 1 and is connected to the spray tower 3, and the spray tower 3 is connected to the gas booster fan 4, the packing tower 5, the electrostatic precipitator 6 and the gas temporary storage buffer cabinet 7 in sequence; the pipeline system consists of a pipeline 9. It is composed of a bladeless booster fan inlet valve 9-1, a rotary kiln head sealing cover inlet valve 9-2 and a branch pipe 9-3, wherein one end of the pipe 9 is connected to the gas temporary storage buffer cabinet 7, and the other end is connected to the rotary kiln head sealing cover 1-1 through the rotary kiln head sealing cover inlet valve 9-2, and the bladeless booster fan inlet valve 9-1 is arranged on the branch pipe 9-3 between the bladeless booster fan 2 and the pipe 9; the feeding system is composed of a feed hopper 8, a double-layer plug-in door 8-1 and an inert gas sealing pipe 8-2, wherein there are two double-layer plug-in doors 8-1, which are arranged on the feed hopper 8 at a certain distance, the inert gas sealing pipe 8-2 is connected to the feed hopper 8 and is located between the two double-layer plug-in doors 8-1, and the feed hopper 8 is arranged at the inlet end of the rotary kiln 1.

[0025] The gas flow channel of the bladeless booster fan 2 is not provided with blades, and the purified gas from the gas temporary storage buffer cabinet 7 is passed into the interior. The gas enters the cylindrical air duct interlayer from the radial pipe of the channel, and high-speed gas is ejected from the outlet to provide power for the pyrolysis gas generated by the rotary kiln.

[0026] The pressure measuring point 1-3 is interlocked with the rotary kiln head sealing cover inlet valve 9-2 for control.

[0027] Furthermore, in order to prevent air from leaking into the feed port 8, the feed port 8 is sealed by a double-layer gate valve 8-1 and an inert sealing gas 8-2 is introduced into the interlayer, and nitrogen is preferably used as the sealing gas.

[0028] The circulating spraying liquid in the spray tower 3 is alkaline solution, which is used to neutralize the acidic components in the gas and increase the service life of subsequent equipment.

[0029] The gas booster fan is preferably a glass fiber reinforced plastic centrifugal blower to reduce the impact of corrosive media in the front-end gas. In addition, the gas booster fan 4 is set after the spray tower 3 and before the packing tower 5 and the electrostatic precipitator 6, thereby reducing the impact of dust, tar and corrosive liquids on the gas booster fan 4 and other equipment.

[0030] A biomass pyrolysis process with a positive system operating pressure includes the following process steps and methods:

[0031] 1) Control the micro-positive pressure of the rotary kiln: According to the feedback from the pressure measuring points 1-3 set at both ends of the rotary kiln 1, the flow rate of the recirculated purified gas entering the rotary kiln 1 is controlled by adjusting the opening size of the inlet valve 9-2 of the rotary kiln head sealing cover, so that the rotary kiln 1 can be operated at a micro-positive pressure;

[0032] 2) Providing power for the pyrolysis gas before the inlet of the gas booster fan 4: By adjusting the opening of the inlet valve 9-1 of the bladeless booster fan, the air volume of the purified gas from the gas temporary storage buffer cabinet 7 entering the bladeless booster fan 2 is controlled. The power fan in the bladeless booster fan 2 is pressurized to form a high-speed jet airflow. The high-speed airflow drives the pyrolysis gas flow through the viscosity of the gas and the local pressure drop formed, providing the power required for the rotary kiln to produce pyrolysis gas. The bladeless booster fan 2 provides a slightly excess amount of purified pyrolysis gas to keep the inlet of the gas booster fan 4 at a positive pressure without causing negative pressure;

[0033] 3) Control the outlet of the gas booster fan 4 to be positive pressure: Because the power provided by the booster fan 2 without blades is relatively small, the gas booster fan 4 configured in the system should be arranged as far forward as possible; the booster fan with blades cannot adapt to a large amount of dust and tar, so the gas booster fan 4 is arranged between the spray tower 3 and the packing tower 5 to provide the main power for the pyrolysis gas, so that the packing tower 5, electrostatic precipitator 6, gas temporary storage buffer cabinet 7 and other equipment at the outlet of the gas booster fan 4 can operate stably at positive pressure.

[0034] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A biomass pyrolysis device with a positive system operating pressure, comprising a rotary kiln, a bladeless booster fan, a spray tower, a gas booster fan, a packing tower, an electrostatic precipitator, a gas temporary storage buffer cabinet, a feeding system and a pipeline system, characterized in that: The rotary kiln is composed of a rotary kiln head sealing cover, a rotary kiln tail sealing cover and a pressure measuring point, wherein the rotary kiln head sealing cover and the rotary kiln tail sealing cover are both provided with pressure measuring points, which are respectively arranged at both ends of the rotary kiln; the bladeless booster fan is arranged at the outlet end of the rotary kiln and connected to the spray tower, and the spray tower is connected to the gas booster fan, the packing tower, the electrostatic precipitator and the gas temporary storage buffer cabinet in sequence; the pipeline system is composed of a pipeline, a bladeless booster fan inlet valve, a rotary kiln head sealing cover inlet valve and a branch pipeline, wherein the pipeline One end of the rotary kiln is connected to the gas temporary storage buffer cabinet, and the other end is connected to the rotary kiln head sealing cover through the rotary kiln head sealing cover inlet valve, and the bladeless booster fan inlet valve is arranged on the branch pipeline between the bladeless booster fan and the pipeline; the feeding system is composed of a feed hopper, a double-layer plug-in door and an inert gas sealing pipeline, wherein there are two double-layer plug-in doors, which are arranged on the feed hopper at a certain interval, the inert gas sealing pipeline is connected to the feed hopper and is located between the two double-layer plug-in doors, and the feed hopper is arranged at the inlet end of the rotary kiln; The pyrolysis process of the biomass pyrolysis device includes the following process steps and methods: 1) Control the micro-positive pressure of the rotary kiln: According to the feedback from the pressure measuring points set at both ends of the rotary kiln, by adjusting the opening size of the inlet valve of the rotary kiln head sealing cover, the flow rate of the recirculated purified gas entering the rotary kiln can be controlled, so that the rotary kiln can operate at a micro-positive pressure; 2) Providing power for the pyrolysis gas before the inlet of the gas booster fan: By adjusting the opening size of the inlet valve of the bladeless booster fan, the air volume of the purified gas from the gas temporary storage buffer cabinet entering the bladeless booster fan is controlled. The purified gas is pressurized by the power fan in the bladeless booster fan to form a high-speed jet airflow, which is ejected from the air outlet of the bladeless gas channel wall. The viscosity of the gas and the local pressure drop formed drive the pyrolysis gas flow, providing the power required for the rotary kiln to produce pyrolysis gas; the bladeless booster fan provides a slightly excess amount of purified pyrolysis gas to keep the inlet of the gas booster fan at a positive pressure without causing negative pressure; 3) Control the outlet of the gas booster fan to be positive pressure: The gas booster fan installed between the spray tower and the packing tower provides power for the pyrolysis gas, so that the gas booster fan outlet equipment can operate stably at positive pressure.

2. A biomass pyrolysis device with a positive system operating pressure according to claim 1, characterized in that: The gas flow channel of the bladeless booster fan is not provided with blades.

3. A biomass pyrolysis device with a positive system operating pressure according to claim 1, characterized in that: The pressure measuring point is interlocked with the inlet valve of the rotary kiln head sealing cover for control.

4. The biomass pyrolysis device with a positive system operating pressure according to claim 1, characterized in that: The sealing inert gas is nitrogen.

5. The biomass pyrolysis device with a positive system operating pressure according to claim 1, characterized in that: The circulating spraying liquid in the spray tower is alkali solution.

6. The biomass pyrolysis device with a positive system operating pressure according to claim 1, characterized in that: The gas booster fan is a glass fiber reinforced plastic centrifugal blower.

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