Green and environmentally friendly mechanical bamboo charcoal carbonization kiln and flue gas purification method

Abstract

The invention discloses a green and environmentally friendly mechanical bamboo charcoal carbonization kiln and a flue gas purification method. An exhaust chamber is provided in the middle of the furnace body, a ventilation hole connected to the furnace is provided at the lower part of one side of the exhaust chamber, an air inlet and a steam nozzle and a combustion gun are provided on the furnace wall opposite to the ventilation hole, the steam nozzle is connected to the steam kettle through a pipeline I with a regulating valve, and the combustion gun is connected to the biomass gas storage cabinet through a pipeline II with a pressure regulating valve and a flame retardant; an exhaust port I connected to a tar separator II is provided at the upper part of the exhaust chamber, an exhaust port II is provided and the air inlet is connected through a pipeline III with a control valve; a top cover is provided at the upper opening of the furnace, a feed port and a smoke outlet connected to the tar separator I are provided on the top cover; the lower opening of the furnace is a charcoal outlet, and the charcoal outlet is connected to a charcoal collecting box. The invention uses waste bamboo materials processed from bamboo products to continuously produce high-temperature bamboo charcoal and bamboo vinegar liquid, obtains biomass gas through flue gas recovery and purification, and improves the utilization of biomass energy.

Description

Technical Field

[0001] The invention relates to a bamboo-wood dry distillation carbonization technology, in particular to a green and environmentally friendly mechanical bamboo charcoal carbonization kiln and a fume purification method. Background Art

[0002] The production of bamboo charcoal began in the 1990s and has reached more than 300,000 tons per year nationwide.

[0003] The existing bamboo carbonization process equipment mainly includes four types: brick-earth kiln, improved brick-earth kiln, dry distillation pyrolysis equipment and continuous vertical kiln.

[0004] The brick-earth kiln and improved brick-earth kiln are still the main methods of bamboo charcoal production at this stage. The burning of bamboo charcoal mainly depends on people's experience, observation, smell and judgment. There is a large temperature difference in the kiln, the product quality is uneven, the manual loading and charcoal removal are labor-intensive, and the intermittent production of flue gas is directly discharged into the atmosphere and cannot be recycled.

[0005] The dry distillation pyrolysis equipment is completely dependent on external heat sources, has low carbonization temperature, high energy consumption, and high labor intensity in manual carbonization. The flue gas produced intermittently is also directly discharged into the atmosphere and cannot be recycled.

[0006] The continuous vertical moving bed carbonization kiln has obvious advantages in carbonization process, product quality, energy consumption and production scale. In its process, bamboo raw materials are added from the top, and the bamboo raw materials gradually move downward by gravity, and are manually discharged from the discharge port after successively undergoing the stages of drying, pre-carbonization, carbonization, calcination and cooling. In the calcination zone, 500° combustion gas generated by a mixed burner is introduced from the outside and flows from bottom to top as a heat carrier to heat the bamboo raw materials, and flows out from the upper part of the bed together with the pyrolysis gas generated during the drying and carbonization of the bamboo raw materials, and then enters the condenser for cooling and condensation to produce bamboo vinegar liquid, but the generated flue gas is not purified and fully recycled, and the degree of mechanization is not high.

[0007] In order to improve the comprehensive utilization of renewable bamboo resources and achieve low-carbon, green, environmentally friendly and sustainable development, it is urgent to develop mechanical and automated production equipment suitable for the development of the domestic bamboo charcoal industry, resolve environmental pollution in the bamboo charcoal production process, and take into account the recycling of bamboo vinegar and flue gas. Summary of the invention

[0008] In order to solve the deficiencies in the prior art, the technical problem to be solved by the present invention is to propose a green and environmentally friendly mechanical bamboo charcoal carbonization kiln and a flue gas purification method to improve the utilization of biomass energy and reduce carbon emissions.

[0009] The green and environmentally friendly mechanical bamboo charcoal carbonization kiln capable of solving the above technical problems comprises a vertical kiln body, wherein the kiln body comprises a shell cover, a heat-insulating layer and a kiln core from the outside to the inside, and the difference is that:

[0010] 1. An exhaust chamber is provided in the middle of the kiln cavity (calcining area) of the kiln core. The exhaust chamber is arranged on the kiln wall on one side of the kiln cavity. Several rows of air holes connected with the kiln cavity are provided at the lower part of the exhaust chamber. An air inlet, a steam nozzle and a combustion gun are provided on the kiln wall on the other side of the kiln cavity opposite to the rows of air holes. The steam nozzle is connected to the steam kettle arranged in the insulation layer through a pipeline I with a regulating valve, and the combustion gun is connected to the biomass gas storage cabinet through a pipeline II with a pressure regulating valve and a flame retardant.

[0011] 2. The upper part of the exhaust chamber is provided with an exhaust port I connected to the tar separator II, and an exhaust port II is provided and connected to the air inlet through a pipeline III with a control valve arranged in the insulation layer.

[0012] 3. A top cover is provided at the upper opening of the kiln core, and a feed inlet and a smoke exhaust port connected to the tar separator I are provided on the top cover.

[0013] 4. The lower opening of the kiln core is a carbon outlet with a screw feeder I disposed therein, and the carbon outlet is connected to a carbon collecting box with a screw feeder II disposed therein.

[0014] In order to monitor the temperature change of the bamboo charcoal in the furnace, a temperature thermoelectric corner is arranged at the air vent position of the exhaust chamber.

[0015] In order to facilitate the autonomous reflow of smoke, the height difference between the exhaust port II and the air inlet is designed to be 30 cm to 150 cm.

[0016] In order to realize automatic feeding, a track connected with the feeding port is provided, a loading hopper for conveying bamboo raw materials is provided on the track, and a movable door which can be opened and closed autonomously by the loading hopper is provided on the feeding port.

[0017] The green and environmentally friendly mechanical bamboo charcoal carbonization kiln fume purification method of the present invention has the following process flow:

[0018] 1. The flue gas generated by the furnace body is led out from the smoke exhaust port and enters the tar separator I. The heavy tar in the flue gas is condensed and deposited, while the bamboo vinegar liquid, light tar and other components enter the flue gas condenser I through the pipeline and are cooled to the daily temperature in the water-cooled pipeline circulation. Most of the bamboo vinegar liquid and light tar are condensed into liquid and flow into the bamboo vinegar liquid storage tank I. A small amount of misty bamboo vinegar liquid and tar enter the spray purifier through the pipeline and the flue gas regulating valve I under the action of the flue gas airflow.

[0019] 2. The high-temperature flue gas in the exhaust chamber is introduced into the tar separator II from the exhaust port and part of the tar is precipitated. The flue gas enters the flue gas condenser II through the pipeline and is cooled to the daily temperature during the circulation of the condensation pipeline. Most of the water, dust and light tar are condensed into liquid and flow into the bamboo vinegar storage tank II. A small amount of mist water, dust and tar enter the spray purifier through the flue gas regulating valve II through the pipeline under the action of the flue gas airflow.

[0020] 3. The spray purifier washes the incoming flue gas to remove some dust and tar. After washing, the flue gas enters the activated carbon purification tower through the pipeline, and the tar particles, dust and water vapor in the flue gas are further adsorbed and filtered out by multiple layers of activated carbon. The purified flue gas enters the bag filter box through the pipeline to further filter out the tar particles, dust and water in the flue gas to obtain biomass fuel gas (main components CO2, H2, CO, CH4 and ethane, etc.). The biomass fuel gas is transported to the biomass fuel gas storage cabinet through a high-pressure air pump.

[0021] Beneficial effects of the present invention:

[0022] 1. The green and environmentally friendly mechanical bamboo charcoal carbonization kiln and flue gas purification method of the present invention utilizes waste bamboo materials to burn high-temperature bamboo charcoal and self-combustion technology to extract high-quality bamboo vinegar liquid, recycle and purify flue gas to obtain biomass gas and introduce it into a biomass gas storage cabinet for storage. The whole production process is low-carbon and zero-emission, which can maximize economic benefits, environmental benefits and social benefits.

[0023] 2. The present invention uses waste bamboo materials from bamboo processing enterprises as raw materials, with materials fed from the upper part of the kiln and charcoal discharged from the bottom. It can continuously and uninterruptedly industrially burn high-temperature bamboo charcoal, extract high-quality bamboo vinegar, ensure uninterrupted recovery of flue gas, and obtain biomass fuel gas through multi-stage purification. The entire production process of continuous supply is mechanized, laying the foundation for subsequent industrial upgrading to automation and intelligence.

[0024] 3. In the structure of the present invention, the combustion torch using biomass gas as fuel can stably control the temperature of the calcination zone in the furnace to maintain a high temperature of 900°C to 1000°C. At the same time, the steam nozzle injects steam to physically activate the bamboo charcoal, effectively improving the adsorption function and quality of the bamboo charcoal. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an implementation mode of the present invention.

[0026] Figure 2 for Figure 1 Flue gas purification flow chart of an implementation method.

[0027] Figure number identification: 1. Kiln core; 2. Smoke exhaust port; 3. Top cover; 4. Feed port; 5. Movable door; 6. Upper hopper; 7. Exhaust chamber; 8. Exhaust port I; 9. Exhaust port II; 10. Air vent; 11. Temperature thermoelectric corner; 12. Coal outlet; 13. Screw feeder I; 14. Combustion gun; 15. Steam nozzle; 16. Air inlet; 17. Steam kettle; 18. Coal collecting box; 19. Screw feeder II; 20. Track. DETAILED DESCRIPTION

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

[0029] The green and environmentally friendly mechanical bamboo charcoal carbonization kiln of the present invention comprises a vertical kiln body, wherein the kiln body comprises a steel shell cover from the outside to the inside, a heat-insulating layer filled with heat-insulating materials and a kiln core 1 built with refractory materials, the kiln cavity of the kiln core 1 is a rectangular upright vertical shaft, the top of the kiln core 1 is provided with a top cover 3 made of steel plates to cover the upper opening of the kiln cavity, one side of the top cover 3 is provided with a smoke exhaust port 2 connected to a tar separator I, the other side of the top cover 3 is provided with a feed port 4, and a movable door 5 is provided at the feed port 4; the lower opening of the kiln cavity is a charcoal outlet 12, a screw feeder I 13 is provided in the charcoal outlet 12, and a charcoal collecting box 18 is provided below the charcoal outlet 12, a screw feeder II 19 is provided in the charcoal collecting box 18, and the bamboo charcoal is cooled in the charcoal collecting box 18 and then transported to a pulverizer for pulverization through the screw feeder II 19, such as Figure 1 shown.

[0030] The middle part of the kiln cavity of the kiln core 1 is a calcining zone. A vertical rectangular exhaust chamber 7 made of refractory material is provided on the kiln wall on the left side of the calcining zone. Several rows of air holes 10 are provided on the lower right side of the exhaust chamber 7 to communicate with the kiln cavity. An air inlet 16 is provided on the right kiln wall opposite to the rows of air holes 10. A plurality of steam nozzles 15 and a plurality of combustion guns 14 are provided on the kiln wall around the air inlet 16. The plurality of steam nozzles 15 are connected to a steam kettle 17 through a pipeline Ⅰ with a regulating valve. The steam kettle 17 is located in the kiln body insulation layer on the side of the charcoal outlet 12, and uses the heat energy of the cooling section to generate steam. The lance 14 is connected to the biomass gas storage cabinet through a pipeline II with a pressure regulating valve and a flame retardant. A temperature thermoelectric corner 11 is provided at the lower air vent 10 of the exhaust chamber 7, and the temperature change of the bamboo charcoal in the kiln cavity can be monitored in real time through the temperature thermoelectric corner 11; multiple combustion lances 14 are directly opposite to the air vent 10 of the exhaust chamber 7, which is conducive to part of the combustion gas penetrating the charcoal material horizontally into the exhaust chamber 7 (the other part of the combustion gas penetrates the bamboo material layer upward), thereby stabilizing the high-temperature carbonization temperature of the bamboo charcoal in the calcining zone at about 900°C. Multiple steam nozzles 15 regularly and quantitatively spray steam into the calcining zone under high temperature conditions, which activates the bamboo charcoal. Figure 1 shown.

[0031] An exhaust port I8 and an exhaust port II9 are provided at the upper part of the exhaust chamber 7. The exhaust port I8 is connected to the tar separator II outside the kiln body through a pipeline IV. The exhaust port II9 is ​​connected to the air inlet 16 through a pipeline III with a control valve arranged in the insulation layer. The position of the exhaust port II9 is ​​30 cm to 150 cm higher than the position of the air inlet 16. Due to the height difference and the effects of the suction and exhaust pressures, the high-temperature flue gas flows back from the exhaust port II9 of the exhaust chamber 7 to the air inlet 16 and enters the kiln chamber for cyclic combustion. Figure 1 shown.

[0032] A track 20 is provided obliquely on the ground corresponding to the feed port 4, and an upper hopper 6 runs on the track 20. When the upper hopper 6 runs upward to reach the feed port 4, the upper hopper 6 pushes open the movable door 5 and discharges the material into the kiln cavity of the kiln core 1. After the material is discharged, the upper hopper 6 runs downward to leave the feed port 4, and the movable door 5 is automatically closed. Figure 1 shown.

[0033] During normal production of the present invention, bamboo material is added into the furnace cavity once every 30 minutes until it is full. The bamboo material moves downward in the furnace cavity due to gravity, and is directly smoked and heated by the flue gas rising from the lower part of the furnace cavity, dehydrated and dried. At the same time, high-boiling-point tar and other organic components in the flue gas condense on the surface of the bamboo material. As the bamboo material gradually moves downward, the temperature continues to rise, and organic substances such as semi-lignin and sugar in the bamboo material begin to pyrolyze and carbonize. As it continues to move downward, the temperature in the furnace cavity is higher, and the amount of pyrolysis products of the bamboo material increases dramatically. These products are in the state of flue gas, which rises along the gaps between the bamboo materials in the furnace cavity, penetrates the material layer, and exchanges heat with the carbonized bamboo material to heat it up. The volume of the bamboo material gradually shrinks during the carbonization process. As the bamboo charcoal continues to move downward, the temperature is higher, and the generated liquid product begins to decrease. At this stage, the combustion gun 14 is used to return The purified flue gas (a small amount or no air is added) is collected as energy to supplement heat energy to remove volatile substances remaining in the bamboo charcoal. When oxygen is present, the combustible volatiles burn, and the bamboo charcoal oxidizes and becomes hot on the surface, and flameless combustion occurs. The calcined bamboo charcoal has a denser charcoal structure. At this time, the temperature is stable at about 900°C. Under this condition, the steam nozzle 15 valve is opened to quantitatively inject steam, which physically activates the bamboo charcoal and increases the specific surface area of ​​the bamboo charcoal. The bamboo charcoal continues to move downward and enters the cooling section. It is only necessary to start the screw feeder Ⅰ13 to quantitatively stir the bamboo charcoal from the furnace cavity to the charcoal collecting box 18. After cooling to about 60°C, the charcoal can be discharged through the screw feeder Ⅱ19. During the entire carbonization process, from the bamboo material entering the feed port 4 of the furnace body 1 to the charcoal being discharged from the charcoal outlet 12, it takes about 24 hours.

[0034] To summarize, the bamboo material is delivered to the feed port 4 by the upper hopper 6 for feeding, and the bamboo material in the kiln chamber gradually moves downward from top to bottom due to its own gravity, and is dried, carbonized, high-temperature calcined and steam activated in sequence at one time, and the generated bamboo charcoal moves downward to the lower part of the kiln chamber for cooling, and is stirred out from the charcoal outlet regularly by the screw feeder Ⅰ13 into the charcoal collecting box 18 for further cooling, and then is transported to the crusher for crushing through the screw feeder Ⅱ19.

[0035] The green and environmentally friendly mechanical bamboo charcoal carbonization kiln fume purification method of the present invention has the following process flow:

[0036] 1. The flue gas is led out from the exhaust port 2 of the kiln core 1 and enters the tar separator Ⅰ to precipitate part of the tar. The flue gas then enters the flue gas condenser Ⅰ and condenses and precipitates most of the bamboo vinegar and tar. The bamboo vinegar is collected in the bamboo vinegar storage tank Ⅰ. The non-condensable flue gas passes through the regulating valve Ⅰ and enters the spray purifier.

[0037] 2. The high-temperature flue gas is led out from the exhaust port II8 of the exhaust chamber 7 and enters the tar separator II to separate out some water vapor and dust. The flue gas then enters the flue gas condenser II and condenses and separates out most of the bamboo vinegar liquid and dust. The bamboo vinegar liquid is collected in the bamboo vinegar storage tank II. The non-condensable flue gas passes through the regulating valve II and enters the spray purifier.

[0038] 3. The spray purifier uses circulating water (after filtering) to wash the dust and tar particles from the incoming flue gas.

[0039] 4. The flue gas enters the activated carbon purification tower, where multiple layers of activated carbon and filter cotton are used to further absorb and remove tar particles, dust and water vapor in the flue gas.

[0040] 5. The flue gas enters the bag filter box to further filter out tar particles, dust and moisture in the flue gas to obtain biomass gas.

[0041] 6. The biomass gas is transported to the biomass gas storage cabinet through a high-pressure gas pump. When the high-pressure gas pump stops, a check valve is used to automatically block the backflow of the biomass gas.

[0042] 7. The biomass gas in the biomass gas storage cabinet is introduced into the combustion gun 14 for recycling.

[0043] 8. The biomass gas stored in the biomass gas storage cabinet can be used for bamboo vinegar distillation and purification and gas generator power generation, and can also be supplied to surrounding residents and enterprises as gas.

Claims

1. A green and environmentally friendly mechanical bamboo charcoal carbonization kiln, comprising a vertical kiln body, wherein the kiln body comprises a shell cover, a heat-insulating layer and a kiln core (1) from the outside to the inside, characterized in that: An exhaust chamber (7) is provided in the middle of the kiln cavity of the kiln core (1), and the exhaust chamber (7) is provided on the kiln wall on one side of the kiln cavity. A plurality of rows of air holes (10) communicating with the kiln cavity are provided at the lower part of the exhaust chamber (7), and an air inlet (16) and a steam nozzle (15) and a combustion gun (14) are provided on the kiln wall on the other side of the kiln cavity opposite to the plurality of rows of air holes (10). The steam nozzle (15) is connected to a steam kettle (17) provided in the heat-insulating layer through a pipeline I with a regulating valve, and the combustion gun (14) is connected to a biomass gas storage cabinet through a pipeline II with a pressure regulating valve and a flame retardant. The exhaust chamber (7) has an exhaust port I (8) in the upper part thereof connected to the tar separator II, and an exhaust port II (9) in the upper part thereof connected to the air inlet (16) via a pipeline III with a control valve in the insulation layer; The upper opening of the kiln core (1) is provided with a top cover (3), and the top cover (3) is provided with a feed inlet (4) and a smoke exhaust port (2) connected to the tar separator I; The lower opening of the kiln core (1) is a charcoal outlet (12) having a screw feeder I (13) therein, and the charcoal outlet (12) is connected to a charcoal collecting box (18) having a screw feeder II (19) therein.

2. The green and environmentally friendly mechanical bamboo charcoal carbonization kiln according to claim 1 is characterized in that: A temperature thermoelectric corner (11) is arranged at the air vent (10) of the exhaust chamber (7) to sense the temperature change of the bamboo charcoal in the furnace.

3. The green and environmentally friendly mechanical bamboo charcoal carbonization kiln according to claim 1 is characterized in that: The height difference between the exhaust port II (9) and the air inlet (16) is 30 cm to 150 cm.

4. The green and environmentally friendly mechanical bamboo charcoal carbonization kiln according to any one of claims 1 to 3, characterized in that: A track (20) connected to the feed port (4) is provided, a loading hopper (6) for transporting bamboo raw materials is provided on the track (20), and a movable door (5) that can be opened and closed autonomously by the loading hopper (6) is provided on the feed port (4).

5. A green and environmentally friendly mechanical bamboo charcoal carbonization kiln fume purification method, characterized in that The green and environmentally friendly mechanical bamboo charcoal carbonization kiln as claimed in claim 4 is adopted, and its process flow is as follows: ①, the flue gas is led out from the exhaust port (2) of the kiln core (1) and enters the tar separator I to separate out part of the tar, and then enters the flue gas condenser I to condense and separate out most of the bamboo vinegar liquid and tar, the bamboo vinegar liquid is collected in the bamboo vinegar liquid storage tank I, and the non-condensable flue gas passes through the regulating valve I and enters the spray purifier; ②, the high-temperature flue gas of the exhaust chamber (7) is introduced into the tar separator II from the exhaust port (8) to separate part of the water, dust and light tar, and the flue gas enters the flue gas condenser II through the pipeline, and is cooled to the normal temperature during the circulation in the condensation pipeline. Most of the water, dust and light tar are condensed into liquid and flow into the bamboo vinegar storage tank II, and a small amount of mist water, dust and tar flow into the spray purifier through the pipeline through the flue gas regulating valve II under the action of the flue gas flow; ③. The spray purifier washes the incoming flue gas to remove some dust and tar. After washing, the flue gas enters the activated carbon purification tower through the pipeline, and the tar particles, dust and water vapor in the flue gas are further adsorbed and filtered out by multiple layers of activated carbon. The purified flue gas enters the bag filter box through the pipeline to further filter out the tar particles, dust and water in the flue gas to obtain biomass gas, which is transported to the biomass gas storage cabinet through a high-pressure air pump.

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